Incidental Takes of Marine Mammals During Specified Activities; Shallow Hazard and Site Clearance Surveys in the Chukchi Sea in 2008, 49421-49443 [E8-19424]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 73, Number 163 (Thursday, August 21, 2008)]
[Notices]
[Pages 49421-49443]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-19424]



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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XJ71


Incidental Takes of Marine Mammals During Specified Activities; 
Shallow Hazard and Site Clearance Surveys in the Chukchi Sea in 2008

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

ACTION: Notice of issuance of a marine mammal incidental take 
authorization.

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SUMMARY:  In accordance with provisions of the Marine Mammal Protection 
Act (MMPA) as amended, notification is hereby given that an Incidental 
Harassment Authorization (IHA) to take marine mammals, by Level B 
harassment, incidental to conducting open water shallow hazard and site 
clearance surveys by ConocoPhillips Alaska, Inc. (CPAI) in the Chukchi 
Sea has been issued.

DATES:  The authorization is effective from August 15, 2008, until 
October 31, 2008.

ADDRESSES:  A copy of the application, IHA, the Final Programmatic 
Environmental Assessment for Arctic Ocean Outer Continental Shelf 
Seismic Surveys--2006 (2006 PEA) prepared by the Minerals Management 
Service (MMS), the 2008 Supplemental Environmental Assessment (SEA) for 
the Issuance of five IHAs for open water seismic surveys and shallow 
hazard and site clearance surveys in the Arctic, and/or a list of 
references used in this document may be obtained by writing to P. 
Michael Payne, Chief, Permits, Conservation and Education Division, 
Office of Protected Resources, National Marine Fisheries Service, 1315 
East-West Highway, Silver Spring, MD 20910-3225, or by telephoning one 
of the contacts listed here (see FOR FURTHER INFORMATION CONTACT).

FOR FURTHER INFORMATION CONTACT:  Shane Guan, Office of Protected 
Resources, NMFS, (301) 713-2289, ext 137 or Brad Smith, Alaska Region, 
NMFS, (907) 271-5006.

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) and will not have 
an unmitigable adverse impact on the availability of the species or 
stock(s) for certain subsistence uses, and if the permissible methods 
of taking and requirements pertaining to the mitigation, monitoring and 
reporting of such takings are set forth. NMFS has defined ``negligible 
impact'' in 50 CFR 216.103 as ``...an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the United States can apply for an authorization 
to incidentally take small numbers of marine mammals by harassment. 
Except with respect to certain activities not pertinent here, the MMPA 
defines ``harassment'' as:
    any act of pursuit, torment, or annoyance which (i) has the 
potential to injure a marine mammal or marine mammal stock in the 
wild [Level A harassment]; or (ii) has the potential to disturb a 
marine mammal or marine mammal stock in the wild by causing 
disruption of behavioral patterns, including, but not limited to, 
migration, breathing, nursing, breeding, feeding, or sheltering 
[Level B harassment].
    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 the authorization.

Summary of Request

    On April 30, 2008, NMFS received an application from CPAI for the 
taking, by Level B harassment, of several species of marine mammals 
incidental to conducting shallow hazard and site clearance surveys 
using acoustic equipment and small airguns in the Chukchi Sea for 30-45 
days from approximately August 10, 2008 until October 31, 2008. The 
geographic region of the proposed activities includes two areas spaced 
about 60 km (37 mi) apart and a path for sampling conditions along a 
potential pipeline route. Each area is about 2,000 km\2\ (772.5 mi\2\) 
with dimensions about 72 km (45 mi) by 62 km (38.5 mi). The two areas 
are about 111 km (69 mi) off the Alaska coast, generally west from the 
village of Wainwright. The marine surveys will be performed from a 
seismic vessel.
    Detailed information on the shallow hazard and seismic surveys can 
be found in the CPAI application and in the Federal Register notice for 
the proposed IHA published on May 23, 2008 (73 FR 30064) (hereinafter 
``FR Notice of Proposed IHA''). No changes have been made to the 
proposed activities since publication of the FR Notice of Proposed IHA.

Comments and Responses

    During the 30-day public comment period, NMFS received comments 
from the Marine Mammal Commission (Commission), the Native Village of 
Point Hope (NVPH); the North Slope Borough (NSB); the Alaska Eskimo 
Whaling Commission (AEWC); the Center for Biological Diversity (CBD), 
Pacific Environment, Natural Resources Defense Council and Alaska 
Wilderness League; Oceana and Ocean Conservancy; the Inupiat Community 
of the Arctic Slope (ICPS); Dr. David E. Bain of the University of 
Washington; and CPAI.

General Comments

    Comment 1: The Commission recommends that NMFS issue the IHA 
provided that (a) the proposed marine mammal mitigation and monitoring 
activities are carried out as described in NMFS' FR Notice of Proposed 
IHA; (b) operations be suspended immediately if a dead or seriously 
injured marine mammal is found in the vicinity of the operations and 
the death or injury could have occurred incidental to those operations; 
and (c) the list of species authorized to be taken be expanded to 
include fin whales.
    Response: NMFS concurs with the Commission's recommendation and 
will require the immediate suspension of seismic activities if a dead 
or injured marine mammal has been sighted within an area where the 
Holder of the IHA deployed and utilized seismic airguns within the past 
24 hours.
    In addition, fin whales have been included in the list of species 
authorized to be taken by Level B harassment for the CPAI shallow 
hazard and site clearance surveys.
    Comment 2: The NSB and ICAS point out that the CPAI application was 
incomplete because the proposed dates and duration of activities vary 
throughout the application documents. In addition, the NSB points out 
that the application has limited information

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about marine mammal distribution, movements, habitat use, population 
size and trends. In addition, the ICAS states that CPAI cannot have 
adequately provided estimates of the number and type of species taken, 
when the IHA application did not adequately acknowledge the 
uncertainties in the available data for this type of operation.
    Response: Comment noted. NMFS reviewed the CPAI application and 
verified the information provided within. At the time when CPAI 
submitted its application, no specific dates had been identified by 
CPAI, but a range of possible dates (i.e., July 15 through November 15, 
2008) for the activity was noted. CPAI has since narrowed its operation 
window to between August 10 and October 31, 2008. CPAI also indicates 
that the seismic activities would take approximately 30-45 days, and it 
is likely to finish the operation earlier if weather permits.
    While information on marine mammals is lacking, NMFS conducted 
relevant research so that complete information is provided in the FR 
Notice of Proposed IHA. In addition, detailed and updated information 
on bowhead whales and other marine mammal species is provided in the 
MMS 2006 PEA, MMS 2007 draft PEIS, NMFS 2008 SEA, and the SAR, as 
referenced in the FR Notice of Proposed IHA.
    Comment 3: The NSB and ICAS recommend that NMFS not authorize 
CPAI's proposed seismic activities. The CBD also urges NMFS not to 
issue any take authorization to CPAI for the proposed activities unless 
and until the agency can ensure that mitigation measures are in place 
that truly avoid adverse impacts to all species and their habitats and 
only after full and adequate public participation has occurred and 
environmental review of the cumulative impacts of such activities on 
these species and their habitats has been undertaken. The CBD feels 
that the proposed IHA does not meet these standards and therefore 
violates the MMPA, ESA, NEPA, and other governing statutes and 
regulations.
    Response: NMFS does not agree with NSB, ICAS, and CBD's 
recommendation and CBD's assessment. In its FR Notice of Proposed IHA, 
NMFS outlined in detail the proposed mitigation and monitoring 
requirements. The implementation of these measures will reduce the 
impacts of the proposed survey on marine mammals and their surrounding 
environment to the lowest level practicable, as required by the MMPA. 
The public was given 30 days to review and comment on these measures, 
in accordance with section 101(a)(5)(D) of the MMPA. NMFS has prepared 
a Supplemental EA to the 2006 MMS PEA. NMFS has fulfilled its 
obligations under NEPA by completing a SEA, which is not required to be 
available for public comment prior to its finalization. Additionally, 
NMFS completed a Biological Opinion in July 2008, as required by 
section 7 of the ESA, which 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. Therefore, 
NMFS does not believe the issuance of an IHA to CPAI would result in a 
violation of the MMPA, ESA, NEPA, and other governing statutes and 
regulations.

Acoustics Impacts

    Comment 4: Citing studies on noise impacts to chinchillas 
(Henderson et al., 1991) and human noise exposure standards by the U.S. 
Occupational Safety Health Administration (OSHA), Dr. Bain states that 
``in humans, chronic exposure to levels of noise too low to generate a 
TTS can result in PTS.'' As OSHA standards require limiting human 
exposure to noise at 115 dBA above threshold to 15 minutes per day, Dr. 
Bain concludes that this level is equivalent to 145 dB re 1 microPa for 
killer whales.
    Response: Although NMFS agrees that chronic exposure to noise 
levels that would not cause TTS could result in hearing impairment in 
the long-term, it is important to understand that such exposure has to 
be of a chronic and long-term nature. The OSHA standards for 
permissible exposure are based on daily impacts throughout an 
employee's career, while the noise exposure to seismic surveys by 
marine mammals is short-term and intermittent, as described in the FR 
Notice of Proposed IHA and in the MMS 2006 PEA. In addition, the 
reference Dr. Bain cites to (Henderson et al., 1991) does not address 
chronic noise impact to humans. The research by Henderson et al. (1991) 
focused on the applicability of the equal energy hypothesis (EEH) to 
impact (impulse) noise exposures on chinchillas, and the results 
indicated that hearing loss resulting from exposure to impact noise did 
not conform to the predictions of the EEH, which is the basis for OSHA 
standards for continuous noise exposure.
    Most importantly, Dr. Bain's extrapolation of 145 dB re 1 microPa 
for killer whale hearing safety from OSHA's 115 dBA is fundamentally 
flawed for three reasons:
    (1) The reference points when using decibel (dB) unit that address 
sound in air and in water are different. For airborne sounds, such as 
those by OSHA, the reference point is 20 microPa, while for underwater 
sounds, the reference point is 1 microPa. There are 26 dB differences 
between the values when different reference points are used for the 
same sound pressure, therefore, 115 dB re 20 microPa is 141 dB re 1 
microPa for the same sound pressure. So 115 dB re 20 microPa in air 
above human threshold (defined as 0 dB re 20 microPa in air) would be 
141 dB re 1 microPa underwater for the same sound pressure. Using the 
lowest threshold of 30 dB re 1 microPa as the killer whale hearing 
threshold, and assuming that noise impacts to killer whales are the 
same as for humans, one could extrapolate that continuous noise 
exposure of 171 dB re 1 microPa (141 dB over the 30 dB threshold) for 
15 minutes for killer whales would be equivalent to humans exposed to 
115 dB re 20 microPa for 15 minutes. Nevertheless, such extrapolation 
still leaves much uncertainty since marine mammals have a different 
mechanism for sound reception (Au, 1993; Richardson et al., 1005). Some 
of the most recent science has shown that for some odontocetes, the 
onset of TTS when exposed to impulse noise is much higher (Finneran et 
al., 2002) than NMFS' current thresholds.
    (2) The decibel values used by OSHA are expressed as broadband A-
weighted sound levels expressed in dBA. This frequency-dependent 
weighting function is used to apply to the sound in accordance with the 
sensitivity of the human ear to different frequencies. Thus, it is 
inappropriate to compare these values to an animal's hearing 
capability, including how an animal perceives sound in air (Richardson 
et al., 1995). For marine mammals, M-weighting functions have been 
suggested based on five different hearing functional groups to address 
different hearing sensitivities of different frequencies by each of the 
marine mammal groups (Southall et al., 2007).
    (3) Finally, the sound characteristic used in OSHA standards is 
continuous sound, while the seismic sound from the proposed shallow 
hazard and site clearance surveys is impulse sound, which by its very 
nature is not a continuous sound.
    Comment 5: Dr. Bain asserts that the zone of immediate risk of 
injury or death for marine mammals should be within the 150-215 dB re 1 
microPa contours and assumes that values can be extrapolated from 
terrestrial species. Dr. Bain supports his argument by stating that 
immediate injury may result from

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brief exposure to sound levels that are 120 to 140 dB above threshold 
in terrestrial mammals, and that marine mammals vary in their best 
sensitivity from killer whales at around 30 dB re 1 microPa (killer 
whale) to 60 dB re 1 microPa (phocids) and 75 dB re 1 microPa 
(otariids)
    Response: NMFS does not agree with Dr. Bain's assessment. As 
discussed in Response to Comment 3, the reference points when using 
decibel (dB) unit that address sound in air is 20 microPa, while in 
water the reference point is 1 microPa. Therefore, the decibel levels 
used to address injury in terrestrial mammals cannot be extrapolated to 
apply marine mammal species without adding a correction factor of 26 dB 
(see Richardson et al., 1995). Even so, plenty of controlled laboratory 
experiments on several marine mammal species (e.g., beluga whales, 
bottlenose dolphins, harbor seals, California sea lions, and northern 
elephant seals) in the past decade point out injuries (PTS) to marine 
mammals would probably occur at much higher sound exposure levels, far 
above the 180 and 190 dB re 1 microPa NMFS currently applies to protect 
cetaceans and pinnipeds from onset of Level A harassment (injury). (see 
review by Southall et al., 2007).
    Comment 6: Citing OSHA (2007) standards for human noise exposure 
standards, Nachtigall et al. (2003), and Henderson et al. (1991), Dr. 
Bain extrapolates that permanent injury to hearing from repeated 
exposure to noise at 120 dB re 1 microPa would occur to killer whales 
after being exposed for 8 hours.
    Response: NMFS does not agree with Dr. Bain's assessment as such an 
extrapolation is invalid. First, as discussed in Response to Comment 4, 
the reference point addressing sound levels or intensities in air, 
which is used by OSHA for the human noise exposure standards, is 
relative to 20 microPa, while the reference point used to address sound 
levels or intensities in water is relative to 1 microPa. These are 
fundamentally different acoustical measures and should not be confused. 
Second, as discussed in Response to Comment 5, the noise exposure 
standard unit used by OSHA is dBA, which is the weighted sound exposure 
level based on human hearing sensitivities, and is not suitable to be 
used in other animals which have very different hearing sensitivities 
across the spectrum. Third, the sound sources used by OSHA are based on 
continuous sound, as is the referenced paper by Nachtigall et al. 
(2003), while the sound sources from the proposed seismic surveys are 
impulse sounds. The prediction of acoustic injury from continuous noise 
exposure is not applicable to impulse noise exposure, as is shown in 
the referenced paper by Henderson et al. (1991); therefore, the 
extrapolation is invalid. Fourth, ambient noise levels at many shallow 
water areas could easily reach 120 dB re 1 microPa, coupled with surf 
and wave actions. If killer whales suffered from permanent hearing 
damage when exposed to this noise level for 8 hours as suggested by Dr. 
Bain, then most killer whales in the coastal areas would have no 
hearing left. The lab controlled experiments by Nachtigall et al. 
(2003), as cited by Dr. Bain, show that an Atlantic bottlenose dolphin 
exhibited TTS of an average 11 dB after being exposed to continued 
noise up to 179 dB re 1 microPa for 55 minutes, a much higher level 
than where Dr. Bain would consider TTS to occur. However, in the wild, 
animals are expected to avoid such intense noise levels, thus 
preventing onset of TTS. Finally, killer whales are not expected to 
occur frequently in the proposed Arctic shallow hazard and site 
clearance project area, so the risk to this species is minimal.
    Comment 7: Citing several papers on killer whales, harbor 
porpoises, and marbeled murrelets, Dr. Bain states that major behavior 
changes of these animals appear to be associated with received levels 
of around 135 dB re 1 microPa, and that minor behavioral changes can 
occur at received levels from 90-110 dB re 1 microPa or lower. Citing 
his own studies, Dr. Bain states that ``killer whales are 40% less 
likely to forage at all when vessels are nearby, perhaps because vessel 
noise masks echoes from prey, making the probability of foraging 
successfully negligible (Bain et al. 2006ab).'' In addition, Dr. Bain 
states that the threshold for effects on harbor porpoise is 90 dB re 1 
microPa, for killer whale is 100 dB re 1 microPa, and for beluga whale 
is 153 dB re 1 microPa, which are all lower than the threshold used to 
estimate the takes. CBD also cited a study of Canadian beluga whales 
showing flight responses from ice-breakers at received sound levels as 
low as 94 dB. In addition, citing NRC (2003), the NVPH states that at 
distances of up to 50 km from icebreakers or other ships operating in 
deep channels, beluga whales respond with a suite of behavioral 
reactions which include rapid swimming away from the ship for distances 
up to 80 km. Finally, citing Richardson et al. (1999) and Richardson 
(2008), the NSB states that bowhead whales were excluded from a zone 
around an active seismic vessel where sound levels were estimated to be 
between 116 and 135 dB, and that bowhead whales were deflected away 
from sounds associated with a development island in the Beaufort Sea at 
levels perhaps approaching ambient sound levels.
    Response: NMFS does not agree with Dr. Bain, CBD, NVPH, and NSB's 
assessment. Although it is possible that marine mammals could react to 
any sound levels detectable above the ambient noise level within the 
animals' respective frequency response range, this does not mean that 
such animals would react in a biologically significant way. In 
addition, as discussed in Response to Comment 5, ambient noise levels 
in many of the world's ocean can easily exceed 90 dB re 1 microPa 
(Urick, 1983).
    According to experts on marine mammal behavior, the degree of 
reaction which constitutes a ``take,'' i.e., a reaction deemed to be 
biologically significant that could potentially disrupt the migration, 
breathing, nursing, breeding, feeding, or sheltering, etc. of a marine 
mammal is complex and context specific, and it depends on several 
variables in addition to the received level of the sound by the 
animals. These additional variables include, but are not limited to, 
other source characteristics (such as frequency range, duty cycle, 
continuous vs. impulse vs. intermittent sounds, duration, moving vs. 
stationary sources, etc.); specific species, populations, and/or 
stocks; prior experience of the animals (naive vs. previously exposed); 
habituation or sensitization of the sound by the animals; and behavior 
context (whether the animal perceives the sound as predatory or simply 
annoyance), etc. (Southall et al., 2007).
    The references cited by Dr. Bain, CBD, NVPH, and NSB's second 
example in this comment address different source characteristics 
(continuous sound rather than impulse sound that are planned for the 
proposed shallow hazard and site clearance surveys) or species (killer 
whales and harbor proposes) that rarely occur in the proposed Arctic 
action area. No reference supporting the ``threshold for effects'' on 
beluga whales is provided by Dr. Bain. Much research regarding bowhead 
and gray whales response to seismic survey noises has been conducted in 
addition to marine mammal monitoring studies during prior seismic 
surveys. Detailed descriptions regarding behavior responses of these 
marine mammals to seismic sounds are available (e.g., Richardson et 
al., 1995; review by Southall et al., 2007), and are also discussed in 
this document.

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    Although migrating bowhead whales were shown to be excluded from a 
zone around an active seismic vessel where sound levels were estimated 
to be at around 120 dB (Richardson et al., 1999), the situation in this 
issue was that the migratory corridor was narrower in the Beaufort Sea. 
As the 120 dB ensonified area filled the narrow migratory corridor, 
thus impedes the movement of the whales. However, NMFS believes that in 
the Chukchi Sea where the area is more open, the 120 dB ensonified area 
would not impede bowhead whale migration. Therefore, there would be no 
significant biological affect to the species. However, as discussed 
below that monitoring a 120-dB radius in the Chukchi Sea is not 
practicable and due to safety concerns, NMFS would not require this 
level of monitoring in the Chukchi Sea.
    Comment 8: Dr. Bain states that sound sources are typically divided 
into continuous and pulsed categories, and that behavioral effects from 
pulsed sound are likely to be independent of the repetition rate and 
duty cycle, and depend primarily on the duration of the survey. Dr. 
Bain further states that intermittent pulses can result in continuously 
received noise when sound arrives via multiple paths, which Dr. Bain 
explains as ``sound that bounces between the bottom and the surface 
will take longer to reach an animal than sound traveling via a direct 
path,'' and that ``noise can mask signals for a brief period before and 
after it is received, meaning an almost continuous received noise can 
mask signals continuously.'' Dr. Bain concludes that ``the subbottom 
profilers proposed for use during the site clearance surveys, with the 
very short intervals between pulses, present a risk of continuous 
masking effects.''
    Response: NMFS does not agree with Dr. Bain's statement on ocean 
acoustics and his subsequent analysis and assessment regarding 
underwater sound propagation and its effects to marine mammals. Within 
the scientific community on ocean acoustics and bioacoustics, two types 
of sounds are traditionally recognized: transient sounds (sounds of 
relatively short duration) and continuous sounds (sounds that go on and 
on). Transient sounds can be further classified into impulsive (such as 
seismic airguns, explosives, pile driving) and non-impulsive (such as 
military tactic sonars) sounds (Richardson et al., 1995). Other 
researchers working on noise impacts to marine mammals classified sound 
types into a single pulse (such as a single explosive), multiple pulses 
(seismic airguns, pile driving), and nonpulses (ship, sonar) (Southall 
et al., 2007). A simple way to distinguish pulses sound from nonpulses 
(continuous sound included) is that the former have rapid rise-time in 
relation to its extremely short duration. As mentioned in Response to 
Comment 7, behavioral responses from marine mammals when exposed to 
underwater noise is complex and context specific, and often depend on 
the sound characteristics (such as received levels, duration, duty 
cycles, frequency, etc.) and other variables.
    NMFS agrees that the distinction between transient and continuous 
sounds is not absolute, as continuous sound from a fast moving vessel 
is often treated as transient sound in relation to a stationary or slow 
moving marine mammal. Further, the distinction between pulses and 
nonpulses is also not always clear as certain pulsed sound sources 
(e.g., seismic airguns and explosives) may become nonpulses at greater 
distances due to signal decay through reverberation and other 
propagation paths. However, Dr. Bain's statement that intermittent 
pulses can result in continuously received noise when sound arrives via 
multiple paths is unfounded. For a marine mammal exposed to noise, 
multipath propagation would expose the animal to the noise multiple 
times, usually each subsequent exposure with lower sound level due to 
loss of acoustic energy from surface and bottom reflections; however, 
the noise arriving via multipath propagation would not become 
continuous sound because the intervals between signals would always 
exist. In addition, noise cannot mask a signal before or after it is 
received by the animal. Noise masking of signals can only occur when 
the unwanted sound (noise) interferes with the signal when received by 
the animal, generally at similar frequencies (Richardson et al., 1995). 
Therefore, Dr. Bain's assessment that the subbottom profilers proposed 
for shallow hazard and site clearance surveys would cause continuous 
masking effects to marine mammals is not supported.
    Comment 9: Dr. Bain states that one characteristic of pulsed 
sources is known as ``time-bandwidth'' product, and he explains that it 
is ``any sound with a finite duration (that is, any real-world sound) 
contains additional frequencies to the nominal frequency. That is, 
pulsed sources that nominally have a frequency that is too high to 
hear, may, in fact, be audible, as the source will contain lower 
frequencies that are detectable.''
    Response: NMFS does not agree with Dr. Bain's statement that high 
frequency pulsed sources nominally contain additional frequencies that 
are audible. The high frequency pulsed sources are expected to operate 
within their frequency range, although some mechanical noise at lower 
frequencies may be produced as a byproduct during the operation. The 
mechanical noise associated with acoustic equipment is expected to be 
low intensity and is not expected to result in harassment of marine 
mammals. Furthermore, the term ``time-bandwidth product'' is generally 
used in signal process, which is irrelevant to the proposed Arctic 
seismic survey.
    Comment 10: Dr. Bain states that the directionality of the sources 
and whether they are on during turns would also affect the ensonified 
area.
    Response: All acoustic sources are downward directional, thus no 
additional ensonified area would result during turns.
    Comment 11: The CBD argues that NMFS analysis of the various high-
energy sound sources on marine mammals is deficient, with NMFS for the 
most part simply asserting that the sound generated by these sources is 
outside the hearing range of most marine mammals. The CBD further 
states that even NMFS acknowledges that odontocetes such as beluga 
whales can in fact hear these sounds.
    Response: NMFS does not agree with the CBD statement as it does not 
have scientific basis. In the FR Notice of the Proposed IHA, NMFS 
stated that the 445 kHz frequency band from the Klein System 3000 dual 
frequency digital side-scan sonar is outside any marine mammal species' 
hearing range, therefore, there would be no effect to marine mammals 
when this frequency is chosen. High frequency sounds above 200 kHz are 
clearly outside the hearing ranges for any marine mammals, which is 
well accepted among marine mammal bioacousticians (Richardson et al., 
1995; Southall et al., 2007). In addition, NMFS never acknowledged that 
odontocetes such as beluga whales can hear sounds above 200 kHz (CBD 
did not provide any reference to support its statement.) Furthermore, 
the sound generated by various side-scan sonars operated at the 
frequency of 120 kHz and beyond produce signals above the hearing 
ranges for mysticetes, such as bowhead, gray, humpback, and minke 
whales (Richardson et al., 1995; Southall et al., 2007).

MMPA Comments

    Comment 12: The CBD, ICAS, and NSB state that since NMFS has not 
promulgated any regulations related to shallow hazard and site 
clearance surveys under the MMPA, and because

[[Page 49425]]

such surveys and associated activities carry the real potential of 
injury or death to marine mammals, neither an IHA nor an LOA can be 
issued for CPAI's proposed activities.
    Response: NMFS does not agree with the CBD, ICAS, and NSB's 
statement. Section 101(a)(5)(D) of the MMPA authorizes Level A (injury) 
harassment and Level B (behavioral) harassment takes. While NMFS' 
regulations indicate that a LOA must be issued if there is a potential 
for serious injury or mortality, NMFS does not believe that CPAI's 
shallow hazard and site clearance survey requires a LOA. As explained 
throughout this Federal Register Notice, it is highly unlikely that 
marine mammals would be exposed to sound pressure levels (SPLs) that 
could result in serious injury or mortality. The best scientific 
information indicates that an auditory injury is unlikely to occur as 
apparently sounds need to be significantly greater than 180 dB for 
injury to occur (Southall et al., 2007).
    NMFS has determined that exposure to several seismic pulses at 
received levels near 200 205 dB (rms) might result in slight temporary 
threshold shift (TTS) (which is not considered injury) in hearing in a 
small odontocete, assuming the TTS threshold is a function of the total 
received pulse energy. Received levels of 200 205 dB or more from the 
loudest acoustic device would be restricted to a radius of no more than 
5 m (16 ft) around a seismic vessel. CPAI's airgun array is considered 
to be of small size. For baleen whales, while there are no data, direct 
or indirect, on levels or properties of sound that are required to 
induce TTS, there is a strong likelihood that baleen whales (bowhead 
and gray whales) would avoid the approaching airguns (or vessel) before 
being exposed to levels high enough for there to be any possibility of 
onset of TTS. For pinnipeds, information indicates that for single 
seismic impulses, sounds would need to be higher than 190 dB rms for 
TTS to occur while exposure to several seismic pulses indicates that 
some pinnipeds may incur TTS at somewhat lower received levels than do 
small odontocetes exposed for similar durations. Consequently, NMFS has 
determined that it would be lawful to issue an IHA to CPAI for the 2008 
seismic survey program.
    Comment 13: The CBD states that it referenced the scientific 
literature linking seismic surveys with marine mammal stranding events 
in its comments to MMS on the 2006 Draft PEA and in comments to NMFS 
and MMS on the 2007 DPEIS. The CBD further states that NMFS' failure to 
address these studies and the threat of serious injury or mortality to 
marine mammals from seismic surveys renders NMFS' conclusory 
determination that serious injury or morality will not occur from 
CPAI's activities arbitrary and capricious.
    Response: The MMS briefly addressed the humpback whale stranding in 
Brazil on page PEA-127 in the 2006 Final PEA. Marine mammal strandings 
are also discussed in the MMS 2007 DPEIS. A more detailed response to 
the cited strandings has been provided in several previous IHA issuance 
notices for seismic surveys (e.g., 73 FR 40512, July 15, 2008). 
Additional information has not been provided by CBD or others regarding 
these strandings. As NMFS has stated, the evidence linking marine 
mammal strandings and seismic surveys remains tenuous 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 33 km 
(18 nm) at 1430 hrs. At 1300 hrs, the seismic vessel was located 46 km 
(25 nm) 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 33 km (18 nm). 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 two 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 International 
Whaling Commission (IWC) in 2004 (SC/56/E28), mentioned a possible link 
between oil and gas seismic activities and the stranding of eight 
humpback whales (seven off the Bahia or Espirito Santo States and one 
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 either extralimital 
or not located in the Chukchi Sea where shallow hazard and site 
clearance survey would occur. Moreover, NMFS notes that in the Arctic, 
marine mammal observation and monitoring have been conducted by the 
industry during periods of industrial activity (and by MMS during times 
with no activity). No strandings or marine mammals in distress have 
been observed during these surveys; nor reported by NSB inhabitants. 
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 CPAI to ramp-up the seismic array to avoid 
a startle effect, strandings are highly unlikely to occur in the Arctic 
Ocean. Ramping-up of the array will allow marine mammals the 
opportunity to vacate the area of ensonification and thus avoid any 
potential injury or impairment of their hearing capabilities. In 
conclusion, NMFS does not expect any marine mammals will incur serious 
injury or mortality as a result of CPAI's shallow hazard and site 
clearance survey in the Chukchi Sea in 2008.
    Comment 14: The CBD states that NMFS failed to adequately specify

[[Page 49426]]

CPAI's activities and impacts of vessels because neither CPAI's 
application nor NMFS' FR Notice of the Proposed IHA mention the various 
transit routes through U.S. waters in the Bering, Chukchi and/or 
Beaufort Seas that these vessels associated with CPAI's surveys would 
take.
    Response: The specified activity that has been proposed and for 
which an IHA has been requested is the use of seismic airguns to 
conduct oil and gas exploration. While the support vessels play a role 
in facilitating seismic operations, NMFS does not expect these 
operations to result in the incidental take of marine mammals. Since 
these support vessels are typically slow-moving, any risk of vessel 
collisions with marine mammals is expected to be minimal. Moreover, 
normal shipping and transit operations do not rise to a level requiring 
an authorization under the MMPA. To require IHAs and LOAs for standard 
shipping would affect NMFS' ability to review activities that have a 
potential to cause harm to marine mammal populations.
    Comment 15: The ICAS and NSB state that a ``small take'' finding is 
inadequate and thus cannot be supported with actual data for the 
proposed CPAI shallow hazard and site clearance survey, therefore, 
placing NMFS in the position of having to make an arbitrary decision. 
In addition, the CBD states that NMFS did not make the distinction 
between ``small number'' and ``negligible impact'' while making the 
decision in the FR Notice of the Proposed IHA.
    Response: NMFS does not agree with the ICAS, NSB, and CBD's 
statement. The analysis provided in the FR Notice of Proposed IHA 
clearly described in detail the numbers of bowhead, gray, and beluga 
whales, and ringed and bearded seals that may be potentially taken by 
Level B harassment as a result of the seismic operations in the Chukchi 
Sea. As clearly stated in the aforementioned Federal Register notice, 
take numbers of these species represent 0.09, 0.19, and 0.06 percent of 
the western Arctic stock of bowhead (population estimated at 10,545), 
eastern North Pacific stock of gray (population estimated at 18,178), 
and the Bering Sea stock of harbor porpoises (population estimated at 
66,078), respectively; and 0.55 and 0.15 percent of the Alaska stocks 
of ringed (population estimated at 249,000 in the Chukchi Sea) and 
bearded seal (population estimated at 250,000-300,000 in the Bering and 
Chukchi Seas) populations within the Chukchi Sea, respectively. 
Although no take number was estimated for humpback, fin, minke, and 
killer whales, harbor porpoises, and spotted and ribbon seals in the 
vicinity of the project area due to their rare presence based in the 
Chukchi Sea, NMFS believes that the harassment of these species would 
be much less likely than those of bowhead and beluga whales and ringed 
and bearded seals. NMFS believes that the numbers for all affected 
species are small relative to their stock size. Separate detailed 
analyses on the levels of take by noise exposure and cumulative impacts 
to these marine mammal species and stocks from a wide spectrum in the 
past, current, and foreseeable future were also conducted and described 
in the aforementioned Federal Register notice, the MMS 2006 PEA, and 
NMFS 2008 SEA. These analyses led NMFS to conclude that while 
behavioral modifications, including temporarily vacating the area 
during the project period may be made by these species to avoid the 
resultant visual and acoustic disturbance, NMFS nonetheless found that 
this action would result in no more than a negligible impact on the 
affected marine mammal species and/or stocks. NMFS also found that the 
proposed action would not have an unmitigable adverse impact on the 
availability of such species or stocks for taking for subsistence uses.
    Comment 16: The CPAI states although for bowhead whales a current 
minimum population is estimated at 9,472, there are more data that 
gives a range of the population up to 13,000 individuals. CPAI requests 
NMFS to consider using the range that more accurately reflects the 
health of the population and its increased growth over the past few 
decades.
    Response: Comment noted. Although several recent studies have put 
the western Arctic stock of bowhead whales in the range of 13,000 
individuals (Gerber et al., 2007; Citta et al., 2007), those studies 
were based on the projection of an approximate 3 percent increase from 
the most recent estimate conducted in 2004 (George et al., 2004). 
However, it is important to recognize that this number (13,000) is 
merely a projection based on the stock assessment survey and does not 
represent the population estimate which is usually based on population 
abundance surveys. NMFS Stock Assessment Report defines the best stock 
estimate for the western Arctic bowhead whales at 10,545, the minimum 
at 9,472 individuals, respectively (Angliss and Outlaw, 2008). For the 
purpose of this activity, NMFS uses the best population estimate, i.e., 
10,545.
    Comment 17: The ICAS points out that the population density 
estimates used in the IHA application to determine the estimated take 
of various species are uncertain because CPAI based population density 
estimates on the published report of marine mammal surveys conducted 
during the Shell and CPAI seismic program in the Chukchi Sea during 
2007 (``LGL Report''). The ICAS further states that while these may be 
the most recent density estimates for the region, they do not include 
estimates for ribbon seals, beluga, humpback whales, or fin whales. 
Finally, the ICAS points out that only 22 percent of the total daylight 
observation effort from the main vessel, and 43 percent of the total 
daylight observation from chase/monitoring vessels for the Chukchi Sea 
survey was useable.
    Response: As ICAS states in its comment these are the most recent 
density estimates of marine mammal species/stocks in the vicinity of 
the proposed seismic survey area. Therefore, NMFS considers these data 
to best reflect the recent marine mammal distribution and abundance in 
the region. These density estimates were adjusted for sighting rates to 
account for animals present but not actually seen. As for those species 
and stocks whose density data are not available, such as beluga, 
humpback, and killer whales, and ribbon seals that could also be 
affected by Level B behavioral harassment, since the occurrence of 
these marine mammals is very rare within the proposed project area 
during the late summer and fall in the Chukchi Sea, take numbers cannot 
be estimated. However, should these animals occur in the project area, 
NMFS believes their take numbers would be much lower (including as a 
percentage of the affected species or stock) as compared to those 
marine mammals whose take numbers were calculated.
    Comment 18: The CBD, ICAS, and NSB state that NMFS' estimates of 
the number of marine mammals that may be harassed based on the 
assumption that sounds below 160 dB re 1 microPa (rms) do not 
constitute harassment is incorrect because an activity can constitute 
harassment if it has the ``potential'' to affect marine mammal 
behavior. In addition, the CBD argues that 160 dB threshold for belugas 
is similarly flawed, as it points out in previous IHA notices, NMFS has 
acknowledged the impacts of sounds on beluga even at significant 
distances from a sound source (up to 20 km).
    Response: NMFS does not agree with CBD, ICAS, and NSB's statement. 
As stated in the MMPA, Level B harassment is defined as any act of

[[Page 49427]]

pursuit, torment, or annoyance which ``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.'' Activities that 
affect marine mammal behavior briefly but not cause disruption of 
behavioral patterns are not considered ``takes.''
    In addition, in regard to impacts to marine mammal behaviors, 
distance is not the only factor that counts. The received levels at 
which marine mammals are affected are related to a number of factors 
including source levels, distances, and acoustic propagation pathways. 
The particular example CBD brought up regarding the seismic surveys by 
the National Science Foundation used airgun arrays with total discharge 
volume of 2,840 in\3\, while the proposed CPAI shallow hazard and site 
clearance survey would only use an airgun array with total discharge 
volume of 40 in\3\. The different source levels determine the 
ensonified zone where marine mammals, including beluga whales, would be 
impacted.
    Comment 19: The ICAS points out that when calculating the estimated 
take number, CPAI used the equation of multiplying the average density 
of species by the length of trackline shots (in km) by twice of the 
distance of transmission loss to 160 dB. The ICAS states that such 
calculation did not include marine mammal takes within the semi-
circular areas defined by the safety radii that would bound the start 
and end-points of seismic surveying. The ICAS states that to account 
for this discrepancy, the above equation should be supplemented with 
the semi-circular areas.
    Response: Comment noted. Although it is customary to include the 
semi-circular areas defined by the safety radii that would bound the 
start and end-points of seismic surveying, the 160-dB distance is very 
short due to the overall low intensity of the acoustic sources. 
Therefore, the ensonified area within the bounded semi-circular areas 
is very small (8 km\2\, or 0.045 percent of the total ensonified area) 
when compared to the total ensonified area even without the semi-
circular areas (17,649 km\2\). A recalculation of the estimated takes 
including the semi-circular areas did not show a difference from the 
original calculation.
    Comment 20: The CBD, ICAS, and NSB state that NMFS has no idea of 
the actual population status of several of the species subject to the 
proposed IHA. For example, in the most recent Stock Assessment Reports 
(SARs) prepared pursuant to the MMPA, NMFS acknowledges it has no 
accurate information on the status of ribbon, spotted, bearded, and 
ringed seals. CBD and NSB both indicate that without these data, NMFS 
cannot conclude that surveys which will harass untold numbers of 
individuals of each species would have no more than a ``negligible 
impact'' on the stocks.
    Response: As required by the MMPA implementing regulations at 50 
CFR 216.102(a), NMFS has used the best scientific information available 
in making its determinations required under the MMPA. The Alaska SAR 
provides population estimates based on past survey work conducted in 
the region, and the SAR shows that based on the most recent 
information, all of these Alaska stocks of ice seal species have robust 
populations. The proposed survey by CPAI is not expected to have 
adverse impacts on ice seals. The activity will last for approximately 
30-45 days in the open-water environment of the Chukchi Sea, where 
bearded and spotted seals are found only occasionally.
    In addition, it is expected that approximately 1,379 ringed and 376 
bearded seals would be affected by Level B behavioral harassment as a 
result of the proposed shallow hazard and site clearance surveys, 
respectively, and that these take numbers represent 0.55 and 0.15 
percent of the Alaska stocks of ringed and bearded seal populations 
within the Chukchi Sea, respectively. Although spotted and ribbon seals 
could also be taken by Level B behavioral harassment as a result of the 
proposed marine surveys in the Chukchi Sea, the probability of take is 
very low since their presence is very rare within the proposed project 
area. Nonetheless, NMFS believes their take numbers would be much lower 
as compared to those marine mammals whose take numbers were calculated.
    Comment 21: Citing research on long term adverse effects to whales 
and dolphins from whale watching activities (Trites and Bain, 2000; 
Bain, 2002; Lusseau et al., 2006), Dr. Bain states that Level B 
behavioral harassment could be the primary threat to cetacean 
populations.
    Response: Although NMFS agrees that long-term, persistent, and 
chronic exposure to Level B harassment could have a profound and 
significant impact on marine mammal populations, such as described in 
the references cited by Dr. Bain, however, those examples do not 
reflect the impacts of seismic surveys to marine mammals for the 
proposed CPAI project. First, whale watching vessels are intentionally 
targeting and making close approaches to cetacean species so the 
tourists onboard can have a better view of the animals. Some of these 
whale/dolphin watching examples cited by Dr. Bain occurred in the 
coastal waters of the Northwest Pacific between April and October and 
for extended periods of time (``[r]ecreational and scientific whale 
watchers were active by around 6 a.m., and some commercial whale 
watching continued until around sunset.'') Thus multiple vessels have 
been documented to be in relatively close proximity to whales for about 
12 hours a day, six months a year, not counting some ``out of season'' 
whale watching activities and after dark commercial filming efforts. In 
addition, noise exposures to whales and dolphins from whale watching 
vessels are probably significant due to the vessels' proximity to the 
animals. To the contrary, the proposed 2008 open water shallow hazard 
and site clearance surveys, along with other potential four seismic 
activities and existing industrial operations in the Chukchi and 
Beaufort Seas, do not intentionally approaching marine mammals in the 
project areas. The two areas situate in a much larger Arctic Ocean 
Basin which is far away from most human impacts. Therefore, the adverse 
effects from each activity are remote and spread farther apart, as 
analyzed in the MMS 2006 PEA and draft EIS. The proposed seismic 
activities would only be conducted between August and October for 30-45 
days, weather permitting. In addition, although studies and monitoring 
reports from previous seismic surveys have detected Level B harassment 
of marine mammals, such as avoidance of certain areas by bowhead and 
beluga whales during the airgun firing, no evidence suggests that such 
behavioral modification is biologically significant or non-negligible 
(Malme et al., 1986; 1988; Richardson et al., 1987; 1999; Miller et 
al., 1999; 2005), as compared to those exposed by chronic whale 
watching vessels cited by Dr. Bain. Therefore, NMFS believes that 
potential impacts to marine mammals in the Arctic by shallow hazard and 
site clearance surveys would be limited to Level B harassment only, and 
due to the limited scale and remoteness of the projects in relation to 
a large area, such adverse effects would not accumulate to the point 
where biologically significant effects would realized.
    Comment 22: Dr. Bain states that changes in behavior resulting from 
noise exposure could lead to indirect injury in marine mammals in the 
wild. He presented several examples to suggest that marine mammals 
repeatedly

[[Page 49428]]

exposed to Level B behavioral harassment could result in Level A takes: 
(1) Gas bubble lesions in beaked whales due to acoustically mediated 
bubble growth or rapid ascent by animals after deep diving; (2) a minke 
whale and harbor porpoises were observed traveling at high speed during 
exposure to mid-frequency sonar in Haro Strait in 2003, and that 
exhaustion from rapid flight could lead to heart or other muscle 
damage, which could cause mortality; (3) citing MMS' (2004) 
Environmental Assessment on Proposed Oil and Gas Lease Sale 195 in the 
Beaufort Sea Planning Area (OCS EIS/EA MMS 2004-028) that feeding 
requires a prey density of 800 mg/m3 and his own observation, Dr. Bain 
is concerned displacement from high productive feeding areas would 
negatively affect individual whales, and that small cetaceans such as 
harbor porpoises would face a risk of death if they are unable to feed 
for periods as short as 48-72 hours; (4) individual killer whales have 
been observed splitting their pod when frightened by sonar, and that 
other killer whales' separation from their social units has resulted in 
death; (5) TTS may lead to harm as a minke whale was nearly struck by a 
research vessel in the area where one had been observed fleeing mid-
frequency sonar; and (6) impaired auditory ability may increase 
predation as white-sided dolphins were attacked by killer whales due to 
the noise of the research vessel caused the approach of killer whales 
undetected by the dolphins.
    Response: NMFS agrees that it is possible that changes in behavior 
or auditory masking resulting from noise exposure could lead to injury 
in marine mammals under certain circumstances in the world, such as 
those examples/hypotheses raised by Dr. Bain. However, it is not likely 
that received sound pressure levels (SPLs) from the shallow hazard and 
site clearance surveys would drastically cause changes in behavior or 
auditory masking in marine mammals in the vicinity of the proposed 
action area. First, marine mammals in the aforementioned examples and 
hypotheses were exposed to high levels of non-pulse intermittent sounds 
such as the military sonar, which has been shown to cause flight 
activities (e.g., Haro Strait killer whales); and continuous sounds 
such as the vessel, which could cause auditory masking when animals are 
closer to the source. The sources produced by the acoustic equipment 
and airguns for the proposed shallow hazard and site clearance surveys 
are impulse sounds used in seismic profiling, bathymetry, and seafloor 
imaging. Unlike military sonar, seismic pulses have an extremely short 
duration (tens to hundreds milliseconds), and relatively long intervals 
(several seconds) between pulses. Therefore, the sound energy levels 
from these acoustic equipment and small airguns are far lower in a 
given time period. Second, the intervals between each short pulse would 
allow the animals to detect any biologically significant signals, and 
thus avoid or prevent auditory masking. In addition, NMFS requires 
mitigation measures to ramp up acoustic sources at a rate of no more 
than 6 dB every 5 minutes. This ramp up would prevent marine mammals 
from being exposed to high level noises without warning, thereby 
eliminating the possibility that animals would dramatically alter their 
behavior (i.e. from a ``startle'' reaction). NMFS also believes that 
long-term displacement of marine mammals from a feeding area is not 
likely because the seismic vessel is constantly moving, and the maximum 
160-dB ensonified radius is about 4 km, which would make an ensonified 
zone of approximately 50 km2 at any given moment, which constitutes a 
very small portion of the Chukchi Sea. In reality, NMFS expects the 
160-dB ensonified zone to be smaller due to absorption and attenuation 
of acoustic energy in the water column.
    Comment 23: Citing that the difference between takes by subsistence 
harvest and potential biological removal (PBR) of the Western Arctic 
stock bowhead whales is about 28 individuals whales, or less than 0.3 
percent of the population, Dr. Bain is concerned that the cumulative 
effects of multiple seismic surveys would not need to be very large to 
push takes over PBR for bowheads.
    Response: NMFS does not agree with Dr. Bain's assessment. None of 
the five proposed 2008 open water Arctic seismic surveys and shallow 
hazard and site clearance surveys is expected to result in any Level A 
harassment (i.e., injury) or mortality. As analyzed in the NMFS 2008 
supplemental environmental assessment (SEA) for the issuance of five 
Arctic seismic surveys and shallow hazard and site clearance surveys, 
all incidental takes of marine mammals are expected to be Level B 
behavioral harassment (NMFS, 2008). Therefore, no PBR would be applied 
for the proposed CPAI seismic activities and other 2008 seismic 
activities in the Chukchi and Beaufort Seas.
    Comment 24: Citing MMS 2006 Programmatic Environmental Assessment 
(MMS 2006 PEA) and the MMS 2007 draft Programmatic Environmental Impact 
Statement (DEIS) for seismic surveys in the Arctic Ocean, Dr. Bain 
states that he supports the mitigation measures established in these 
documents that no more than 12 cow/calf pairs and aggregation of 
feeding or resting bowheads are within the area to be ensonified by 120 
dB and 160 dB, respectively. The CBD also states that the monitoring of 
a 120 dB safety zone for bowhead cow/calf pairs and monitoring of a 160 
dB safety zone for large groups of bowhead or gray whales (> 12 
individuals) were required by NMFS in 2006 and were practicable. The 
CBD states that the failure to require such conditions, or at least 
analyze it, violates the MMPA. Dr. Bain presumes that these numbers 
(using 120 and 160 dBs) reflect the difference between takes allocated 
to hunters and the PBR for the stock. Dr. Bain further suggests that 
this number be applied to all seismic activities combined, not 
individual seismic surveys, thus, if four seismic surveys occur 
concurrently, no single survey should be allowed to affect the 
migration of more than 3 cow/calf pairs or 3 aggregation of feeding or 
resting bowhead whales.
    Response: First, the additional mitigation measures in the MMS 2006 
PEA and the MMS 2007 draft PEIS, as well as in the 2007 NMFS SEA for 
the issuance of an IHA to Shell Offshore Inc. for its open water 
seismic surveys conducted in the Chukchi and Beaufort Seas in 2007, 
establish safety (shut-down) zones of 120 dB re 1 microPa for an 
aggregation of four or more bowhead cow/calf pairs and 160 dB re 1 
microPa for an aggregation of 12 or more bowhead or gray whales, not 12 
cow/calf pairs as Dr. Bain states in his comment. The rationale for 
this cautious and conservative approach when addressing the 120-dB and 
160-dB safety zones is clearly stated in the MMS 2006 PEA. These 
additional mitigation and monitoring measures were identified through 
the analyses to further reduce the potential for adverse environmental 
impacts and, depending on the scope of seismic-survey activities, could 
be adopted as requirements for seismic-survey-related marine mammal 
incidental take authorizations. With respect to CBD's concern that 
these measures were ``practicable'' in 2006, NMFS has re-evaluated the 
practicability of requiring aerial monitoring to the 120-dB isopleth in 
the Chukchi. NMFS has determined that it is not practicable to conduct 
aerial monitoring to the 120-dB isopleth because aerial surveys have 
currently been determined to be impracticable

[[Page 49429]]

due to lack of adequate landing facilities, the prevalence of fog and 
other inclement weather in that area, thereby resulting in safety 
concerns. Additionally, these conditions are analyzed in NMFS' 2008 
SEA. These numbers have nothing to do with the PBR of the bowhead whale 
stock, as assumed by Dr. Bain. As discussed in FR Notice of Proposed 
IHA, the proposed 2008 Arctic seismic surveys and shallow hazard and 
site clearance surveys are not expected to result in Level A harassment 
(injury) or mortality.
    In addition, Dr. Bain's suggestion of ``breaking up'' the 
aggregated takes of bowheads into small subsets that can be 
``allocated'' to each seismic survey is based on his assumption that 
these numbers were set by PBR. NMFS does not support this suggestion 
because it has no scientific support other than assumption. The safety 
zones of 120-dB for four or more cow/calf pairs and 160-dB for an 
aggregation of 12 bowhead or gray whales are based on the biology of 
the bowhead and gray whales as analyzed in the MMS 2007 draft PEIS.
    The threshold of four or more fall-migrating bowhead whale cow/calf 
pairs was set based on the following: (a) cow/calf pairs are identified 
as the most vulnerable portion of the population and disruption of 
their biologically significant behaviors or their avoidance of 
important habitats is more likely to lead to population level impacts; 
(b) mitigation measures for this portion of the population should be 
cautiously developed to ensure that takings are at the lowest 
practicable level and that significance is avoided; (c) bowhead whale 
cow/calf pairs migrate in groupings or pulses and the observed presence 
of cow/calf pairs by surveys generally indicates that additional cow/
calf pairs are present but unseen; (d) using professional judgment, 
NMFS and MMS have determined that the presence of four or more cow/calf 
pairs (as observed during surveys) indicates that enough cow/calf pairs 
are likely present (but some unseen) in the area in numbers equal to or 
greater than 12 animals; and (e) the potential for significance to 
occur therefore increases when four or more bowhead whale cow/calf 
pairs are observed (MMS, 2007).
    The threshold of an aggregation of 12 or more bowhead or gray 
whales is based on the following premises: (a) whales aggregate in 
order to communicate and perform ``biologically significant'' behaviors 
(as defined by NRC, 2005), such as feeding, resting, socializing, 
mating, and calving; (b) aggregations of animals can also indicate an 
area of preferred habitat and locations where biologically significant 
behaviors are likely occurring; (c) disruptions of these biologically 
significant behaviors and important habitats have a greater potential 
to lead to population level effects (i.e., result in limiting 
reproductive potential or recruiting success, impeding important 
mother/calf bonding); (d) protective measures should be designed to 
reduce the potential for disruption of biologically significant 
behaviors or help ensure whales do not avoid important key habitat 
areas (and thus potentially negate a negligible impact finding under 
the MMPA); and (e) standard scientific acceptance that the presence of 
observed whales (i.e., at the surface) during monitoring surveys 
indicates that additional whales are also present in the area but non-
detectable (i.e., below the surface) (MMS, 2007).
    Comment 25: Dr. Bain is concerned that the North Pacific right 
whale is excluded from consideration for the proposed seismic activity 
in the Chukchi Sea. Citing Nowacek et al. (2004), Dr. Bain further 
states that the [North] Atlantic right whale is less easily disturbed 
[than the North Pacific right whale], is known to be affected by 
received levels below 135 dB.
    Response: NMFS does not agree with Dr. Bain and believes his 
concern is unwarranted. The North Pacific right whales are found in the 
northern part of the Pacific, such as the Bering Sea and the Gulf of 
Alaska (Moore et al.; 2000; 2002; LeDuc et al., 2001; Waite et al., 
2003; Mellinger et al., 2004; Wade et al., 2006). They do not enter 
Chukchi Sea in the Arctic Ocean, where the proposed seismic activity is 
planned. In addition, NMFS is not able to verify Dr. Bain's statement 
that the North Atlantic right whale is less easily disturbed than the 
North Pacific right whale, since he did not provide a supporting 
reference.
    Comment 26: Dr. Bain is concerned that many species are sedentary, 
territorial, or have strong tendencies toward site fidelity, and that 
these species are unlikely to move away from a noise sourc