[Federal Register Volume 71, Number 163 (Wednesday, August 23, 2006)]
[Notices]
[Pages 49418-49433]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-7097]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 071406A]


Small Takes of Marine Mammals Incidental to Specified Activities; 
Seismic Surveys in the Chukchi Sea off Alaska

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

ACTION: Notice of Issuance of an Incidental Harassment Authorization.

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SUMMARY: In accordance with regulations implementing the Marine Mammal 
Protection Act (MMPA) as amended, notification is hereby given that an 
Incidental Harassment Authorization (IHA) to take marine mammals, by 
harassment, incidental to conducting marine geophysical seismic 
surveys, on oil and gas lease blocks located on Outer Continental Shelf 
(OCS) waters in the Chukchi Sea. has been issued to GX Technology of 
Houston, Texas (GXT).

DATES: Effective from August 15, 2006, through December 31, 2006.

ADDRESSES: The application, a list of references used in this document, 
and/or the IHA are available 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. A copy of the application, the IHA and/or the research 
monitoring plan is also available at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.
    A copy of the Minerals Management Service's (MMS) Programmatic 
Environmental Assessment (PEA) is available on-line at: http://www.mms.gov/alaska/ref/pea_be.htm
    Documents cited in this document, that are not available through 
standard public (inter-library loan) access, may be viewed, by 
appointment, during regular business hours at this address.

FOR FURTHER INFORMATION CONTACT: Kenneth Hollingshead, Office of 
Protected Resources, NMFS, (301) 713-2289, ext 128.

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

[[Page 49419]]

intentional, taking of small numbers 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.
    An 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 subsistence uses and 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 March 28, 2006, NMFS received an IHA application from GXT to 
take several species of marine mammals incidental to conducting a 
marine seismic survey in the Chukchi and Beaufort Seas. On March 31, 
2006, GXT notified NMFS that it would not be conducting surveys in the 
U.S. Beaufort Sea, but would instead conduct seismic surveys in the 
Canadian Exclusive Economic Zone (EEZ) in the Beaufort Sea.
    GXT plans to collect seismic reflection data that reveal the sub-
bottom profile for assessments of petroleum reserves in the area. 
Ultra-deep 2D lines such as those to be collected are used to better 
evaluate the evolution of the petroleum system at the basin level, 
including identifying source rocks, migration pathways, and play types. 
All planned geophysical data acquisition activities will be conducted 
by GXT. The geophysical survey will be performed from the M/V 
Discoverer (the original proposed action was for the M/V Discoverer II 
to conduct the seismic survey, see Comments and Responses).
    The M/V Discoverer will arrive in Dutch Harbor about June 1st where 
it will be resupplied and the crew will change in preparation for the 
beginning of seismic surveys in the Chukchi Sea. Depending on ice 
conditions, the vessel will mobilize to arrive off Cape Lisburne and 
begin survey data acquisition as soon as possible; the expected date is 
July 30, 2006, depending upon ice conditions. Two alternative schedule 
scenarios are planned depending on the seasonal ice conditions 
encountered in 2006.
    The first (and most likely) scenario entails operations beginning 
in the Chukchi Sea about July 30, 2006. Collection of seismic data will 
continue there until there is sufficient open water near Point Barrow 
and in the Alaskan Beaufort Sea to allow passage east into the Canadian 
Beaufort Sea. The M/V Discoverer will then leave the Chukchi Sea, 
traverse the Alaskan Beaufort Sea, and conduct surveys in the Canadian 
Beaufort Sea under GX Technology Canada Ltd. of Calgary, Alberta,. a 
company incorporated in Canada. Seismic operations will continue in the 
Canadian Beaufort Sea until all planned seismic lines have been 
completed, or new ice begins forming in the fall. The vessel will then 
return to the Chukchi Sea to complete any lines not previously 
surveyed, or until weather and sea ice force an end to the survey 
season, which is not expected to continue past November 30, 2006.
    The second scenario will occur only if sea ice in the Beaufort Sea 
does not move far enough offshore to allow the M/V Discoverer to travel 
to the Canadian Beaufort. In that case, the vessel will continue 
operations in the Chukchi Sea until all survey lines there are 
completed. The M/V Discoverer will then exit the area and transit to 
Dutch Harbor to de-mobilize. Helicopter operations are not planned as a 
part of the seismic survey and would occur only in the case of an 
emergency.
    The total seismic survey program, if it can be completed, will 
consist of a total of about 5302 km (3294.5 mi) of surveys, not 
including transits when the airguns are not operating. Water depths 
within the study area are 30-3800 m (98-12467 ft). Approximately 14 
percent of the survey (about 742 km (461 mi)) will occur in water 
depths greater than 500 m (1640 ft), 5 percent of the survey (about 265 
km (165 mi)) will be conducted in water 200-500 m (656-1640 ft) deep, 
and most (81 percent) of the survey (about 4295 km (2669 mi) ) will 
occur in water less than 200 m (656 ft). None of the survey will take 
place in nearshore waters within 25 km (15.5 mi) of the coast (the 
Chukchi polynya zone).
    The M/V Discoverer will tow an airgun array directly astern and a 
single hydrophone streamer up to 9 km long. The array will consist of 
36 sleeve airguns (8 40 in\3\, 4 70 in3, 4 80 in\3\, 12 100 in\3\, and 
8 150 in\3\) that produce a total discharge of 3320 in\3\. The vessel 
will travel along pre-determined lines at about 4-5 knots while the 
airgun array discharges about every 20 seconds (shot interval about 46 
m (151 ft). The towed hydrophone streamer will receive the reflected 
signals and transfer the data to an on-board processing system. The 
proposed survey lines cover a large portion of the Chukchi Sea, and tie 
together known wells, core locations, fault lines and other geophysical 
points of interest. Specifications of the M/V Discoverer and the 36-
airgun array that will be used can be found in GXT's application 
(Appendices A and B; see ADDRESSES).
    The survey consists of a large grid of 14 lines oriented to connect 
previous well locations and core sample locations as well as geological 
structures in the sub-surface. The extent of the lines allows 
flexibility to mitigate any interaction with seasonal subsistence 
hunting as well as species migration patterns. GXT has restricted its 
survey lines along the shore to the area of the MMS lease sales 
(greater than 25 km (15.5 mi) offshore) to exclude the nearshore 
Chukchi polynya, through which marine mammals migrate in the spring. 
Lines will be chosen based on marine mammal migration and subsistence 
hunting, as well as ice movement and geophysical importance. If heavy 
ice conditions are encountered in the northern portions of the survey 
area, some trackline planned for that region may be shifted to ice-free 
waters within the central or southern portions of the survey area. 
There will be additional seismic operations associated with airgun 
testing, start up, and repeat coverage of any areas where initial data

[[Page 49420]]

quality is sub-standard. In addition to the airgun array, a pinger 
system will be used to position the 36-airgun array and streamer 
relative to the vessel.
    The M/V Discoverer will serve as the platform from which vessel-
based marine mammal observers will watch for marine mammals before and 
during airgun operations (see Mitigation and Monitoring later in this 
document). A ``chase boat'' will be used to protect the streamer from 
damage and otherwise lend support to the M/V Discoverer. It will not be 
introducing sounds into the water beyond those associated with normal 
vessel operations.

Characteristics of Airgun Pulses

    Discussion of the characteristics of airgun pulses was provided in 
several previous Federal Register documents (see 69 FR 31792 (June 7, 
2004) or 69 FR 34996 (June 23, 2004)) and is not repeated here. 
Additional information can be found in the MMS PEA and Appendix C in 
GXT's application. Reviewers are encouraged to read these documents for 
additional information.

Safety Radii

    The rms (root mean square) received sound pressure levels (SPLs) 
that are used to estimate marine mammal takes and establish safety 
zones for mitigation are not directly comparable to the peak or peak-
to-peak values normally used by geophysicists to characterize source 
levels of airguns (GXT IHA Application, Appendix C). The measurement 
units used to describe airgun sources, peak or peak-to-peak dB, are 
always higher than the rms dB referred to in much of the biological 
literature and by NMFS. A measured broadband received level of 160 dB 
re 1 microPa (rms) in the far field would typically correspond to a 
peak measurement of about 170 to 172 dB, and to a peak-to-peak 
measurement of about 176 to 178 decibels, as measured for the same 
pulse received at the same location (Greene, 1997; McCauley et 
al.,1998, 2000a). The precise difference between rms and peak or peak-
to-peak values for a given pulse depends on the frequency content and 
duration of the pulse, among other factors. However, the rms level is 
always lower than the peak or peak-to-peak level for an airgun-type 
source.
    Received sound fields have been modeled by GXT using the Gundalf 
software suite (Gundalf, 2002) for the 36-airgun array that will be 
used during this survey (GXT IHA Application Appendix B). GXT used an 
advanced version of the Gundalf modeling program to estimate the rms 
received sound levels (in dB re 1 microPa) at different distances from 
the seismic source on a broadband basis (0-256 Hz). These estimates are 
believed by GXT to be conservative (i.e., likely to overestimate the 
distance at which received levels will be [gteqt]160 dB) and most 
applicable to the 36-airgun array discharging 3320 in\3\ in water 
depths between 200 and 500 m (656-1640 ft), or ``intermediate depths.'' 
The safety radii are expected by GXT to be smaller in ``deep'' (greater 
than 500 m) and ``shallow'' (less than 200 m) water. Empirical data do 
not exist for this airgun array's sound propagation, so those data will 
be collected at the beginning of seismic operations. During this 
initial period, a 1.5X precautionary factor will be applied to the 190 
dB and 180 dB radii listed here in Table 1, for use as shutdown radii 
for marine mammals in the water. Once empirical measurements of the 
sound produced by GXT's airgun array have been collected and analyzed, 
the safety radii presented in Table 1 may be adjusted to reflect those 
results.
    As discussed in detail later in this document (see Mitigation), the 
airguns will be powered down immediately (or shut down if necessary) 
when cetaceans or pinnipeds are detected within or about to enter the 
[gteqt]180 dB or [gteqt]190 dB radii, respectively. A single 40 in\3\ 
sleeve airgun will be used as the power down source. The 160-190 dB re 
1 microPa (rms) radii for this source will be measured during acoustic 
verification measurements at the beginning of seismic shooting.
[GRAPHIC] [TIFF OMITTED] TN23AU06.043


[[Page 49421]]



Comments and Responses

    A notice of receipt of GXT's MMPA application and NMFS' proposal to 
issue an IHA to GXT was published in the Federal Register on June 6, 
2006 (71 FR 32045). That notice described, in detail, GXT's proposed 
activity, the marine mammal species that may be affected by the 
activity, and the anticipated effects on marine mammals. During the 30-
day public comment period on GXT's application, substantive comments 
were received from the Marine Mammal Commission (Commission), the 
Alaska Eskimo Whaling Commission (AEWC), the Center for Biological 
Diversity (CBD) and GXT. The comments of the Commission are identical 
to its comments on NMFS' proposed IHA to Shell. NMFS has addressed 
these comments in its Federal Register notice of issuance of that IHA 
and they are not repeated here. That notice will publish shortly. The 
CBD suggested that the comments submitted by the Natural Resources 
Defense Council on the PEA also be considered for the issuance of the 
IHA. These comments have been considered in the Final PEA and in NMFS' 
and MMS' Finding of No Significant Impact (FONSI) determinations. Many 
of those 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 either in this 
section or in notices of issuance of IHAs to Shell and ConocoPhillips 
(71 FR 43112, July 31, 2006).

Activity Concerns

    Comment 1: GXT notes that the source vessel for the planned seismic 
survey in the Chukchi Sea will be the M/V Discoverer, not the M/V 
Discoverer II. Because the M/V Discoverer is the sister-ship of the M/V 
Discoverer II, the two vessels are almost identical. The M/V Discoverer 
is 2 m (6.6 ft) longer, 2 m (6.6 ft) narrower, and its draft is 0.7 m 
(2.3 ft) less than the M/V Discoverer II. Because of the great 
similarities between the two vessels, the noise generated by the 
operations of each of the two sister-ships is expected to be 
approximately the same. The airgun array described in the notice is 
accurate for the M/V Discoverer.
    Response: NMFS has made the appropriate modifications to this 
document.

MMPA Concerns

    Comment 2: The CBD states that waters in the Canadian Beaufort EEZ 
are ``high seas'' and therefore GXT's activities there are subject to 
the take prohibition in section 102(a)(1) of the MMPA, 16 U.S.C. 
1372(a)(1). They cite the Center for Biological Diversity v. National 
Science Foundation, (2002 WL 31548073 (N.D. Cal, Oct 30, 2002).
    Response: MMPA section 102(a)(1) applies only to persons and 
vessels subject to the jurisdiction of the United States (16 U.S.C. 
1372(a)(1)). The vessel is Chinese-owned and flagged in the Bahamas, 
and there will be no person subject to the jurisdiction of the United 
States owning or operating the vessel while it is in the Canadian EEZ. 
Further, the persons responsible for the conduct of the seismic survey 
in the Canadian EEZ are not U.S. citizens (and the seismic work in the 
Canadian EEZ will be conducted under permits issued by the Canadian 
government to GX Technology Ltd of Calgary, Canada). Therefore, section 
102(a)(1) of the MMPA is irrelevant.
    Comment 3: The CBD also states that ``the MMPA prohibits any person 
to use ``any port, harbor, or other place'' under U.S. jurisdiction to 
take marine mammals. 16 U.S.C. 1372(a)(2)(B). Because GXT will start 
operations from Dutch Harbor, which is under U.S. jurisdiction, CBD 
believes this brings GXT's surveys in the Canadian Beaufort Sea within 
the jurisdictional reach of the MMPA.
    Response: We do not interpret the use of Dutch Harbor in this 
manner as falling within the meaning of 16 U.S.C. 1372(a)(2)(B). We 
also point out that the surveys in the Chukchi and Beaufort Seas are 
not one continuous survey. See also NMFS' response to Comment MMPAC1.
    Comment 4: The CBD believes that the proposed IHA does not 
adequately 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 GXT's description of the activity and the locations for conducting 
seismic surveys meet the requirements of the MMPA. GXT intends to 
conduct seismic surveys within the area of the Chukchi Sea indicated in 
its application.

Marine Mammal Impact Concerns

    Comment 5: 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 GXT's activities arbitrary and capricious.
    Response: 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 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 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

[[Page 49422]]

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 
Chukchi Sea seismic areas. 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 GXT 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 serious injury or mortality as a result of 
Arctic Ocean seismic surveys in 2006.
    Comment 6: The CBD states that the IHA notice provide no support 
for NMFS' ``conclusion'' on small numbers and negligible impact. For 
GXT's proposed seismic surveys in the Chukchi, the number of bowheads 
likely to be harassed is 337. In absolute terms these numbers cannot be 
considered ``small.'' Even relative to population size, the higher 
estimate represents a third of the estimated population of bowheads. 
For beluga whales, the number harassed is estimated to be 650; for gray 
whales the number is 481. None of these numbers can be considered 
``small.'' Given the MMPA is designed to protect not just populations, 
but individual marine mammals, any number in the hundreds or thousands 
simply cannot be considered ``small.
    Response: As discussed elsewhere in this document, NMFS believes 
that the small numbers requirement has been satisfied (see Estimates of 
Marine Mammal Exposures later in this document). The maximum number of 
bowhead whales that may be exposed to seismic sounds is estimated to be 
337 (Table 2). With a population size estimated to be 10,545 bowheads, 
NMFS estimates that the maximum percentage of the population that will 
be exposed would be approximately 3 percent, not 33 percent. For beluga 
whales and gray whales these numbers represent less than 5 percent of 
each population stock size.
    Also, NMFS must clarify that the numbers provided in Table 2 
estimate the numbers indicate the number of animals that would be 
exposed to seismic noise at the SPLs indicated, not the numbers of 
animals that will be taken by Level B (behavioral) harassment. Not all 
individuals of a marine mammal species would be expected to react at 
the same level or even react at all as indicated in GXT's application.
    Comment 7: The CBD notes that as many as 12,223 ringed seals and 
over 7000 bearded seals may be harassed in the Chukchi Sea. Bearded 
seals with over seven thousand to be harassed. The total numbers of 
marine mammals potentially harassed in the Chukchi from GXT's seismic 
surveys is almost twenty thousand individuals. These numbers cannot 
rationally be considered ``small.'' The proposed seismic surveys simply 
are not designed to avoid impacting more than small numbers of marine 
mammals and, therefore, the IHA must be denied.
    Response: NMFS is not required to consider the total estimated take 
across all species in making its small numbers determination. The 
species most likely to be harassed during seismic surveys in the Arctic 
Ocean area is the ringed seal, with a ``best estimate'' of animals 
being exposed to sound levels of 160 dB or greater of 3056 in the 
Chukchi Sea. As stated previously, this does not mean that this number 
of ringed seals will be taken by Level B harassment, it is only the 
best estimate of the number of animals that could be exposed to an SPL 
of 160 dB or greater and, theoretically could be harassed due to the 
noise. However, Moulton and Lawson (2002) indicate that most pinnipeds 
exposed to seismic sounds in the Beaufort Sea 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)). 
In addition, 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 (as part of GXT's survey will be), 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 very few 
animals.
    Although it might be argued that the absolute number of ringed seal 
behavioral harassment numbers may not be small, the number of 
``exposures'' is relatively small, representing less than 4 percent of 
the regional population of that species (245,000) if each ``exposure'' 
represented an individual ringed seal and maximum ringed seal density 
was used. Bearded (and spotted) seals take estimates ignore the 
likelihood that these two species frequent polar ice areas where 
seismic vessels cannot operate and, therefore, likely overestimate take 
levels.
    Comment 8: The CBD believes that NMFS' assumption that sounds below 
160 dB do not constitute harassment is incorrect and, therefore, 
underestimates the possible true impact. The CBD notes that their NEPA 
comments pointed out numerous studies showing significant behavioral 
impacts from received sounds well below 160 dB and even the PEA 
acknowledges that impacts to bowheads occur at levels of 120 dB and 
below. This clearly meets the statutory definition of harassment and 
demonstrates that the numbers of marine mammals estimated to be taken 
by GXT's activity likely constitute a significant underestimate. NMFS' 
``small numbers'' conclusion is therefore arbitrary and capricious.
    Response: The best information available to date for reactions by 
bowhead whales to impulse noise, such as seismic, is based on the 
results from the 1998 aerial survey (as supplemented by data from 
earlier years) as reported in Miller et al. (1999). In 1998, bowhead 
whales below the water surface at a distance of 20 km (12.4 mi) from an 
airgun array received pulses of about 117-135 dB re 1 
microParms, depending upon propagation. Corresponding levels 
at 30 km (18.6 mi) were about 107-126 dB re 1 microParms. 
Miller et al. (1999) surmise that deflection may have begun about 35 km 
(21.7 mi) to the east of the seismic operations, but did not provide 
SPL measurements to that distance, and noted that sound propagation has 
not been studied as extensively eastward in the alongshore direction, 
as it has northward, in the offshore direction. Therefore, while this 
single year of data analysis indicates that bowhead whales may make 
minor deflections in swimming direction at a distance of 30-35 km 
(18.6-21.7 mi), there is no indication that the SPL where deflection 
first begins is at 120 dB, it could be at another SPL lower or higher 
than 120 dB. Miller et al. (1999) also note that the received levels at 
20-30 km (12.4-18.6 mi) were considerably lower in 1998 than have 
previously been shown to elicit avoidance in bowheads exposed to 
seismic pulses. However, the seismic airgun array used in 1998 was 
larger

[[Page 49423]]

than the ones used in 1996 and 1997 (1500 in\3\ vs 1320 in\3\). It 
should also be pointed out that these minor course changes are during 
migration and, as indicated in the Final PEA, have not been seen at 
other times of the year and during other activities. Therefore, until 
additional data is obtained to indicate at what SPL bowhead whales 
begin to deflect away from a seismic airgun array, NMFS will not adopt 
any single SPL value below 160 dB and apply it across the board for all 
species and in all circumstances. NMFS therefore continues to estimate 
``takings'' under the MMPA from impulse noises, such as seismic, as 
being at a distance of 160 dB (re 1 microPa).
    Comment 9: The CBD states that NMFS has no idea of the actual 
population status of several of the species subject to the proposed 
IHA. NMFS acknowledges (in its Status of Stock's Reports (SARS)) it has 
no accurate information on the status of spotted seals, bearded seals, 
and ringed seals. Without this data, NMFS cannot make a rational 
``negligible impact'' finding. This is particularly so given there is 
real reason to be concerned about the status of these populations. Such 
concerns were raised recently in a letter to NMFS from the Commission 
that cautioned against assuming a stable population given apparent 
changes in the Bering, Chukchi, and Beaufort Seas and the declines of 
many other Alaska marine mammals.
    Response: NMFS uses the best information available when making a 
determination that the impacts from an activity will have a negligible 
impact on the affected species and stocks of marine mammals. This 
information comes from many sources, including NMFS' SARS reports. As 
noted in GXT's application for the pinniped species mentioned by CBD:
    (1) Bearded seals: While no reliable estimate of bearded seal 
abundance is available for the Beaufort Sea (Angliss and Lodge, 2002), 
results from aerial surveys of the eastern Chukchi Sea indicated 
densities of up to 0.149 bearded seals/km\2\ and a population of 4862 
animals, although actual abundance may be much higher (Angliss and 
Lodge, 2004).
    (2) Spotted seals: While the total number of spotted seals in 
Alaskan waters is not known (Angliss and Lodge, 2002), the estimate is 
most likely between several thousand and several tens of thousands 
(Rugh et al., 1997).
    (3) Ringed seals: While no estimate for the size of the Alaska 
ringed seal stock is currently available (Angliss and Lodge, 2002), 
past ringed seal population estimates in the Bering-Chukchi-Beaufort 
area ranged from 1-1.5 million (Frost, 1985) to 3.3-3.6 million (Frost 
et al., 1988). Frost and Lowry (1981) estimated 80,000 ringed seals in 
the Beaufort Sea during summer and 40,000 during winter.
    At present, there is no scientific information that population 
declines are occurring or have occurred. Moreover, long-term monitoring 
studies of Alaskan marine mammals being conducted by NMFS and others 
would note significant population declines.

Cumulative Effects Concerns

    Comment 10: In its comments on NMFS' negligible impact 
determination, CBD states that NMFS must look at the immediate effects 
of GXT's seismic surveys together with the cumulative effects over 
multiple years of other oil and gas activities and anthropogenic risk 
factors such as climate change, both onshore and offshore Alaska. CBD 
contends that these cumulative effects should be analyzed with respect 
to their potential population consequences at the species level, stock 
level, and at the local population level, citing Anderson v. Evans, 371 
F.3d 475 (9th Cir. 2004).
    Response: Under section 101(a)(5)(D) of the MMPA, NMFS is required 
to determine whether the taking by the IHA applicant's specified 
activity will have a negligible impact on the affected marine mammal 
species or population stocks. 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 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 and it is part of NMFS' 
Administrative Record. Finally, the proposition for which CBD cites 
Anderson was in the context of the court's analysis under NEPA, not 
MMPA section 101(a)(5)(D), which was not at issue in Anderson.

Mitigation Concerns

    Comment 11: GXT suggests (as noted in section XI of GXT's IHA 
application) that the 190-dB radius, not the 180-dB radius, is the 
appropriate zone that should be fully visible to observers and clear of 
all marine mammal sightings for 30 minutes prior to ramp-up from a full 
shutdown of all airguns. This includes during night-time or other times 
of reduced visibility. The rationale for this is as follows:
    (1) Pinnipeds, to which the 190-dB safety zone applies, have not 
shown much avoidance of operating seismic arrays in the Beaufort Sea 
(Harris et al., 2001; Moulton and Lawson, 2002; Miller et al., 2005). 
Therefore, it is appropriate to assume that some pinnipeds will not 
move out of the safety zone during a ramp-up. Accordingly, the 190-dB 
zone should be visible before a ramp-up begins.
    (2) The types of cetaceans likely to be encountered (bowheads, 
belugas, and gray whales) have shown avoidance of active seismic 
surveys and it is expected that they will move beyond the full 180-dB 
radius for the airgun array during the ramp-up (Malme and Miles, 1985; 
Malme et al., 1986, 1988; Richardson et al., 1986, 1999; Miller et al. 
2005). Thus, it is not critical that the full 180-dB radius applicable 
to cetaceans be visible prior to commencing a ramp-up.
    Response: While NMFS fully expects that bowhead and beluga whales 
will avoid seismic activity by large distances, scientific information 
is less clear that the gray whales will do so. Documentation of 
avoidance in either the Beaufort or Chukchi seas is lacking and, 
although Malme et al. (1985) indicate that gray whales will avoid 
seismic activity, later research by Clark and Tyack (1999) duplicating 
the work of Malme et al. (1985) indicates that gray whale avoidance 
response is context dependent. Essentially, gray whales did not react 
(avoid) the sound source when the source was not directly in its 
migratory path. Also, because GXT will be conducting seismic operations 
in the Chukchi Sea where additional cetaceans may be affected (killer 
whales and harbor porpoise (although these species are more sensitive 
to higher frequencies than seismic)), NMFS has determined that the 
scientific evidence to support using only 190-dB isopleth as a safety 
zone for all species of marine mammals is not supportable at this time.
    Comment 12: The CBD believes that the proposed IHA notice ignores 
the MMPA statutory requirement that all methods and means of ensuring 
the least practicable impact have been adopted.
    Response: NMFS believes that the mitigation measures required under 
GXT's IHA will result in the least

[[Page 49424]]

practicable adverse impact. Inherent in implementing these mitigation 
measures is some level of uncertainty on the distribution and abundance 
of cetaceans in the Chukchi Sea and on whether the acoustic impacts 
observed in the Beaufort Sea also occur in the Chukchi Sea. Additional 
information on this concern can be found later in this document and in 
previous responses to this concern by CBD (see for example, comment 
MiC2 and MiC3 in Shell's IHA notice.

Monitoring Concerns

    Comment 13: The AEWC incorporates by reference into its comments on 
the GXT application, the comments submitted by the North Slope 
Borough's Department of Wildlife Management regarding the most recent 
version of the ``Marine Mammal Monitoring, Mitigation, and 
Investigatory Plan for Seismic Exploration in the Alaskan Chukchi Sea, 
2006'' (Monitoring Plan) prepared on behalf of Shell, ConocoPhillips 
and GXT.
    Response: Please see the discussion on marine mammal monitoring 
later in this document.

Subsistence Concerns

    Comment 14: The AEWC notes that GXT's proposed data acquisition in 
the Chukchi Sea includes work near shore, the AEWC is concerned about 
the potential effects on the fall bowhead whale subsistence hunt at 
Barrow and possibly Wainwright and Pt. Hope. The village of Barrow 
traditionally has hunted during both the spring and fall bowhead whale 
migraitons; however, unfavorable ice conditions in the Chukchi Sea this 
year resulted in a very poor spring bowhead whale hunt for all of the 
spring (hunt) villages. As a result, the villages of Wainwright and 
Point Hope have announced that they may attempt to hunt bowheads this 
fall.
    To protect the fall bowhead hunt at Barrow, the Conflict Avoidance 
Agreement (CAA) (see description later in this document) includes a 
prohibition on all seismic operations beginning on September 10th 
through October 25\th\, from Pitt Point on the east side of Smith Bay 
to the east to a location about half way between Barrow and Peard Bay 
to the west. However, given the outcome of the spring bowhead hunt in 
the Chukchi villages (which had not been completed at the time the CAA 
was negotiated), the AEWC requests NMFS' assistance in providing 
further protections for the near-shore areas of the Chukchi during the 
fall bowhead migration in this region. In particular, the AEWC requests 
NMFS include in GXT's IHA, provisions designed to protect the nearshore 
area from the effects of seismic operations, either directly or through 
sound propagation. The AEWC suggests that GXT refrain from conducting 
seismic operations within 50 miles of the Chukchi coast beginning 
September 15 through October 25\th\, from the halfway point between 
Barrow and Peard Bay to 50 miles due west of Cape Lisburne.
    Response: The IHA requires GXT to comply with the conditions of the 
CAA. This requirement ensures that, to the greatest extent practicable, 
GXT's activities will not have an unmitigable adverse impact on 
subsistence uses of marine mammals, particularly bowhead whales.
    Comment 15: The CBD disagrees with NMFS' ``no unmitigable adverse 
impact'' determination for the same reasons it disagrees with NMFS' 
``negligible impact'' and ``small numbers'' determinations.
    Response: This comment is not specific enough for a response, but 
we disagree with the conclusion.

Endangered Species Act (ESA) Concerns

    Comment 16: The CBD states that previous Biological Opinions for 
the bowhead whale have been inadequate. The CBD hopes NMFS will perform 
a full analysis required by law.
    Response: NMFS has issued a biological opinion regarding the 
effects of this action 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).
    Comment 17: The CBD states that NMFS may authorize incidental take 
of bowhead whales under the ESA pursuant to section 7(b)(4), but only 
where such take occurs while ``carrying out an otherwise lawful 
activity.'' CBD believes GXT's proposed activities violate the MMPA and 
NEPA and therefore are not ``otherwise lawful.'' Any take authorization 
for the bowhead whale would therefore violate the ESA as well as other 
statutes.
    Response: NMFS believes it has complied with the requirements of 
the MMPA, the ESA and NEPA in connection with the incidental harassment 
of marine mammals by GXT while conducting activities permitted under 
MMS' jurisdiction.

NEPA Concerns

    Comment 18: The CBD notes that they submitted comments on the MMS 
PEA along with comments on GXT's IHA application. Subsequent to CBD's 
May 10, 2006 letter on the PEA, they believe additional information has 
come to light that requires the preparation of an EIS in accordance 
with 40 CFR 1508.27(b)(4). The CBD notes that the Native Village of 
Kaktovik passed a resolution opposing Shell's seismic survey plans and 
the Native Village of Point Hope also officially expressed its 
opposition to this summer's various seismic surveys. The CBD believes 
that NMFS cannot rationally adopt the PEA and make a FONSI on this 
action. Instead, it must prepare a full EIS analyzing the effects of 
Shell's proposed activities in the context of cumulative effects of all 
other natural and anthropogenic impacts on marine mammals, habitats and 
communities of the Chukchi and Beaufort seas.
    Response: While the Villages of Point Hope and Kaktovik expressed 
opposition to seismic activities (specifically by Shell) in the Chukchi 
and Beaufort seas this year (as coastal native Alaskan communities have 
done for many years), the Whaling Captains' Associations of Point Hope, 
Kaktovik, Nuiqsut, and Wainwright signed a CAA with Shell, 
ConocoPhillips and GXT. This CAA indicates to NMFS that seismic 
exploration activities by these companies will not have an unmitigable 
adverse impact on the availability of marine mammals for subsistence 
uses, including bowheads and belugas. This, along with the required 
mitigation and monitoring measures, informed NMFS' FONSI.

Description of Habitat and Marine Mammals Affected by the Activity

    A detailed description of the Chukchi Sea ecosystem and its 
associated marine mammals can be found in several documents, including 
the MMS PEA and does not need to be repeated here. The Chukchi Seas 
support a diverse assemblage of marine mammals, including bowhead 
whales (Balaena mysticetus), gray whales (Eschrichtius robustus), 
beluga whales (Delphinapterus leucas), killer whales (Orcinus orca), 
harbor porpoise (Phocoena phocoena), ringed seals (Phoca hispida), 
spotted seals (Phoca largha), bearded seals (Erignathus barbatus), 
walrus (Odobenus rosmarus) and polar bears (Ursus maritimus). These 
latter two species are under the jurisdiction of the U.S. Fish and 
Wildlife Service (USFWS) and are not discussed further in this 
document. Abundance estimates of these species can be found in Table 2 
in GXT's application. Descriptions of the biology and distribution of 
the marine mammal species under NMFS' jurisdiction can be

[[Page 49425]]

found in GXT's application, MMS' PEA, and several other documents 
(Corps of Engineers, 1999; Lentfer, 1988; MMS, 1992, 1996; Hill et al., 
1999). Information on marine mammal hearing capabilities can be found 
in GXT's application.
    Information on these species can also be found in NMFS Stock 
Assessment Reports. The Alaska stock assessment document is available 
at: http://www.nmfs.noaa.gov/pr/readingrm/MMSARS/sar2003akfinal.pdf. 
Updated species reports are available at: http://www.nmfs.noaa.gov/pr/readingrm/MMSARS/2005alaskasummarySARs.pdf. Please refer to these 
documents for information on these species.

Potential Impacts of Seismic Surveys on Marine Mammals

    Disturbance by seismic noise is the principal means of taking by 
this activity. Support vessels and marine mammal survey aircraft (if 
required) 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.
    As outlined in several 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;
    (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 
presumably 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.

Potential Effects of Seismic Airgun Arrays on Marine Mammals

    GXT believes that the effects of sounds from airguns might include 
one or more of the following: (1) Tolerance; (2) masking of natural 
sounds; (2) behavioral disturbance; and (3) at least in theory, hearing 
impairment and other non-auditory physical effects (Richardson et al., 
1995). Discussion on marine mammal tolerance to noise, masking effects 
of noise, temporary or permanent hearing impairment, and non-auditory 
effects can be found in GXT's IHA application, and previous Federal 
Register notices for seismic activities (e.g., see 69 FR 74906, 
December 14, 2004). In summary, NMFS and GXT believe that it is 
unlikely that there would be any cases of temporary or permanent 
hearing impairment, non-auditory physical effects, or strandings. NMFS 
has also provided information previously on the potential effects of 
noise on marine mammal species expected to be in the Chukchi Sea region 
(see 71 FR 26055 (May 3, 2006), 71 FR 27685 (May 12, 2006) and 71 FR 
32045 (June 6, 2006)). Readers are encouraged to review those documents 
for additional information.

Potential Effects of Pinger Signals on Marine Mammals

    A description of the pinger system (DigiRANGE I and II, Input/
Output, Inc) that will be used during seismic operations to position 
the airgun array and hydrophone streamer relative to the vessel was 
described in the proposed IHA notice for GXT June 6, 2006 (71 FR 32045) 
and is not repeated here.

Estimates of Marine Mammal Exposures to SPLs of 160 dB or Higher (Level 
B Harassment)

    Table 2 of this Federal Register notice provides the estimates of 
the number of potential sound exposure to levels 160 dB re 1 microPa 
(rms) or greater. The methodology used and the assumptions made to 
estimate incidental take by Level B harassment, at sound pressure 
levels at 160 dB or above, by seismic and the numbers of marine mammals 
that might be affected during the proposed seismic survey area in the 
Chukchi Sea are presented in the GXT application. While GXT believes, 
based on the evidence summarized in the application, that the 170-dB 
criterion is appropriate for estimating Level B harassment for 
delphinids and pinnipeds, which tend to be less responsive (whereas the 
160-dB criterion is considered relevant for other cetaceans), there is 
no empirical evidence to indicate that some delphinid species do not 
respond at the lower level (i.e., 160 dB). Also, since delphinids are 
not expected to be affected by this action, this suggested new 
criterion is not relevant for this action. While the application cites 
recent empirical information regarding responses of pinnipeds to low-
frequency seismic sounds, the information cited in the application is 
less than convincing. As a result, NMFS will continue to use the 160-dB 
isopleth to estimate the numbers of pinnipeds that may be taken by 
Level B harassment. However, while some autumn migrating bowheads in 
the Beaufort Sea have been found to react to a noise threshold closer 
to 130 dB re 1 microParms; (Miller et al., 1999; Richardson 
et al., 1999), evidence in Richardson et al. (1986) and Miller et al. 
(2005) indicate that the 160-dB criterion is suitable for summering 
bowhead whales.
    The following estimates are based on a consideration of the number 
of marine mammals that might be exposed to SPLs of 160 dB or more along 
about 5302 line-km (3294 line mi) of seismic surveys across the Chukchi 
Sea. An assumed total of 6628 km (4118 mi) of trackline in the Chukchi 
Sea includes a 25 percent allowance over and above the planned 
trackline to allow for turns and lines that might have to be repeated 
because of poor data quality, or for minor changes to the survey 
design.
    The anticipated radii of influence of the M/V Discoverer's pinger 
system are

[[Page 49426]]

much less than those for the airgun array (for those species that can 
hear it). It is assumed that, during simultaneous operations of the 
airgun array and pinger system, any marine mammals close enough to be 
affected by the pingers will already be affected by the airguns. 
However, whether or not the airguns are operating simultaneously with 
the pinger system, odontocetes and seals are expected to exhibit no 
more than momentary and inconsequential responses to the pingers, based 
on evidence of their reactions from pingers on maritime private and 
commercial vessels using similar instrumentation for obtaining 
bathymetric information. Therefore, no additional take numbers are 
provided for animals exposed to pingers.
    The estimates of marine mammals that might be exposed to SPLs that 
could result in Level B harassment are based on available data about 
mammal distribution and densities at different locations and times of 
the year. The proposed survey covers a large area in the Chukchi Sea in 
two different seasons. The estimates of marine mammal densities have 
therefore been separated both spatially and temporarily in an attempt 
to represent the distribution of animals expected to be encountered 
over the duration of the survey. Density estimates in the Chukchi Sea 
have been derived for two time periods, the early summer period 
covering the months of June and July (Table 3 in GXT's IHA 
application), and the late fall period including most of October and 
November (Table 4 in GXT's IHA application). For the Chukchi Sea, 
cetacean densities during the summer were estimated from effort and 
sighting data in Moore et al. (2000) and Richardson and Thomson (eds., 
2002), while pinniped densities were estimated from Bengtson (2005) and 
Moulton and Lawson (2002).
    The potential number of events when members of each species might 
be exposed to received levels 160 dB re 1 microPa (rms) or greater was 
calculated by summing the results for each season and habitat zone by 
multiplying:
    (1) The expected species density, either ``average'' (i.e., best 
estimate) or ``maximum'' (see Tables 3 and 4 in GXT's IHA application),
    (2) The anticipated total line-kilometers of operations with the 
36-airgun array in the time period, and habitat zone to which that 
density applies after applying a 25 percent allowance for possible 
additional line kilometers (see GXT IHA application) and
    (3) The cross-track distances within which received sound levels 
are predicted to be [gteqt]160 (Table 1 in this document).
    Some marine mammals that are estimated to be exposed, particularly 
migrating bowhead whales, might show avoidance reactions before being 
exposed to 160 dB re 1 microPa (rms). Thus, these calculations actually 
estimate the number of exposures to >160 dB that would occur if there 
were no earlier avoidance of the area ensonified to that level.
    For the 36-airgun array, the cross track distance is 2X the 
predicted 160-dB radius predicted by the Gundalf model or 6000 m (19685 
ft). Applying the approach described above, 55,560 km2 of open-water 
habitat in the Chukchi Sea would be within the 160-dB isopleth over the 
course of the seismic project (though not at any given moment). After 
adding the 25-percent contingency to the expected number of line 
kilometers of seismic run, the number of exposures is calculated based 
on 69,450 km2.
    The numbers of exposures in the two habitat categories (open water 
and ice margin) were then summed for each species. GXT's estimate of 
marine mammal exposures to SPL of 160 dB (and greater) is provided in 
Tables 5, 6, and 7 in the IHA application. Table 2 in this document is 
a summary of that information.

TABLE 2. Summary of the number of potential exposures of marine mammals to received sound levels in the water of
[gteqt]160 dB during GXT's proposed seismic program in the Chukchi Sea, Alaska, -15 June -25 July and -1 October
   - 30 November, 2006. Not all marine mammals will change their behavior when exposed to these sound levels,
                    although some might alter their behavior somewhat when levels are lower.
                                Number of Exposure to Sound Levels [gteqt]160 dB
----------------------------------------------------------------------------------------------------------------
                                         Summer                   Fall                        Total
----------------------------------------------------------------------------------------------------------------
            Species                Average     Maximum     Average    Maximum    Average          Maximum
----------------------------------------------------------------------------------------------------------------
Odontocetes                      ..........  ..........  ..........  .........  .........  .....................
  Monodontidae                   ..........  ..........  ..........  .........  .........  .....................
    Beluga                       3           11          160         639        163                         650
  Delphinidae                    ..........  ..........  ..........  .........  .........  .....................
  Killer whale                   3           11          5           22         8                            33
  Phocoenidae                    ..........  ..........  ..........  .........  .........  .....................
    Harbor porpoise              0           0           0           0          0                             0
Mysticetes                       ..........  ..........  ..........  .........  .........  .....................
    Bowhead whale                1           8           57          328        59                          337
    Gray whale                   1           4           83          333        84                          337
    Minke whale                  3           11          5           22         8                            33
    Fin whale                    1           2           1           4          2                             7
  Total Cetaceans                11          47          313         1349       324                        1396
Pinnipeds                        ..........  ..........  ..........  .........  .........  .....................
    Bearded seal                 586         2344        1190        4760       1776                       7104
    Spotted seal                 6           23          12          47         17                           70
    Ringed seal                  1008        4033        2047        8189       3056                      12223
    Harbor seal                  0           0           0           0          0                             0
                                 ..........  ..........  ..........  .........  .........  .....................
Total Pinnipeds                  1600        6401        3249        12996      4849                      19397
----------------------------------------------------------------------------------------------------------------


[[Page 49427]]

    GXT and NMFS believe that bowhead, beluga, and gray whales are the 
only cetaceans expected to be exposed to noise levels [gteqt]160-dB 
levels. The estimates show that one endangered cetacean species, the 
bowhead whale, is expected to be exposed to such noise levels, unless 
bowheads avoid the approaching survey vessel before the received levels 
reach 160 dB. Migrating bowheads are likely to do so, though summering 
bowheads, if encountered may not. For convenience, GXT refers to either 
eventuality as an ``exposure''. As a result, GXT's average and maximum 
estimates for bowhead whale exposures are 59 and 337, respectively 
(Table 2). The average and maximum estimates of the number of exposures 
of cetaceans are beluga (163 and 650) and gray whale (84 and 337). The 
seasonal breakdown of these numbers is shown in Tables 5 and 6 and 
totaled in Table 7 in the application and Table 2 in this document. 
Other cetacean species may occasionally occur near the seismic areas, 
but given their low estimated densities in the area, they are not 
likely to be exposed to SPLs of 160 dB or greater. With a population 
size estimated to be 10,545 bowheads, NMFS estimates that the maximum 
percentage of the population that will be exposed would be 
approximately 3 percent. For beluga whales and gray whales these 
numbers represent less than 5 percent of each population stock size. 
NMFS believes that this number of potential Level B harassment takes is 
small.
    The ringed seal is the most widespread and abundant pinniped in 
ice-covered arctic waters, but there is a great deal of annual 
variation in population size and distribution of these marine mammals. 
Ringed seals account for the vast majority of marine mammals expected 
to be encountered, and, therefore, exposed to airgun sounds with 
received levels [gteqt]160 dB re 1 microPa (rms) during the proposed 
seismic survey. Haley and Ireland (2006) reported that 20 percent of 
ringed seals remained on the ice when a seismic vessel passed. Because 
the SPL radii for this project are assumed to be larger than those 
found in the Haley and Ireland (2006) project, NMFS and GXT believe a 
larger percent of ringed seals within the 160-dB radii are likely to 
remain on the ice while the M/V Discoverer passes, and not subject to 
potential harassment. Therefore, GXT's estimates of numbers of ringed 
seals that might be exposed to sound levels 160 dB re 1 microPa (rms) 
were reduced by 50 percent to account for animals that are expected to 
be out of the water, and hence exposed to much lower levels of seismic 
sounds. The average (and maximum) estimate is that 3056 (max. 12,223) 
ringed seals out of a Beaufort/Chukchi Sea population of 245,048 seals 
might be exposed to seismic sounds with received levels >160 dB. NMFS 
believes that this number of potential Level B harassment takes (less 
than 4 percent of the population size of ringed seals is small.
    Two other species of pinnipeds are expected to be encountered 
during the proposed seismic survey. With Alaskan stock estimates of 
300-450,000 and 1000 respectively, the bearded seal has average and 
maximum exposure estimates of 1776 and 7104, and the spotted seal has 
average and maximum exposure estimates of 17 and 70, respectively. 
These exposure estimates are small numbers relative to their population 
sizes. Finally, the harbor seal is unlikely to be encountered so no 
exposure estimates have been made.

Effects of Seismic Survey Noise on Subsistence Uses

    GXT (2006) reports that marine mammals are legally hunted in 
Alaskan waters by coastal Alaska Natives; species hunted include 
bowhead and beluga whales; ringed, spotted, and bearded seals; 
walruses, and polar bears. The importance of each of the various 
species varies among the communities based largely on availability. 
Bowhead whales, belugas, and walruses are the marine mammal species 
primarily harvested during the time of the proposed seismic survey. 
There is little or no bowhead hunting by the community of Point Lay, so 
beluga and walrus hunting are of more importance there. Members of the 
Wainwright community do hunt bowhead whales in the spring, although 
bowhead whale hunting conditions there are often more difficult than 
elsewhere, and traditionally they do not hunt bowheads during seasons 
when GXT's seismic operation would occur. Depending on the level of 
success during the spring bowhead hunt, Wainwright residents may be 
very dependent on the presence of belugas in a nearby lagoon system 
during July and August. Barrow residents focus hunting efforts on 
bowhead whales during the spring and generally do not hunt beluga then. 
Barrow residents also hunt in the fall.
    Bowhead whale hunting is the key activity in the subsistence 
economies of Barrow and Wainwright. 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.
    An overall quota system for the hunting of bowhead whales was 
established by the International Whaling Commission in 1977. The quota 
is now regulated through an agreement between NMFS and the Alaska 
Eskimo Whaling Commission (AEWC). The AEWC allots the number of bowhead 
whales that each whaling community may harvest annually (USDI/BLM, 
2005).
    Bowhead whales migrate around northern Alaska twice each year, 
during the spring and autumn, and are hunted in both seasons. Bowhead 
whales are hunted from Wainwright only during the spring migration and 
animals are not successfully harvested every year. The spring hunt 
there and at Barrow occurs after leads open due to the deterioration of 
pack ice; the spring hunt typically occurs from early April until the 
first week of June. The fall migration of bowhead whales that summer in 
the eastern Beaufort Sea typically begins in late August or September. 
Fall migration into Alaskan waters is primarily during September and 
October. However, in recent years a small number of bowheads have been 
seen or heard offshore from the Prudhoe Bay region during the last week 
of August (Treacy, 1993; LGL and Greeneridge, 1996; Greene, 1997; 
Greene et al., 1999; Blackwell et al., 2004).
    The location of the fall subsistence hunt near Barrow depends on 
ice conditions and (in some years) industrial activities that influence 
the bowheads movements as they move west (Brower, 1996). In the fall, 
subsistence hunters use aluminum or fiberglass boats with outboards. 
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). The 
autumn hunt usually begins in Barrow in mid-September, and mainly 
occurs in waters east and northeast of Point Barrow. The whales have 
usually left the Beaufort Sea by late October (Treacy, 2002a,b).
    The scheduling of this seismic survey has been discussed with 
representatives of those concerned with the subsistence bowhead hunt, 
most notably the AEWC, the Barrow Whaling Captains' Association, and 
the North Slope Borough (NSB) Department of Wildlife Management.
    The starting date for seismic surveys in the Chukchi Sea is well 
after the end of the spring bowhead migration and hunt at Wainwright 
and Barrow. Similarly, the resumption of seismic activities in the 
Chukchi Sea in October will occur after most subsistence whaling from 
Barrow has been

[[Page 49428]]

completed and if the hunt is still active, seismic operations will be 
conducted far from Barrow to avoid conflicting with subsistence hunting 
activities.
    Beluga whales are available to subsistence hunters along the coast 
of Alaska in the spring when pack-ice conditions deteriorate and leads 
open up. Belugas may remain in coastal areas or lagoons through June 
and sometimes into July and August. The community of Point Lay is 
heavily dependent on the hunting of belugas in Kasegaluk Lagoon for 
subsistence meat. From 1983-1992 the average annual harvest was about 
40 whales (Fuller and George, 1997). In Wainwright and Barrow, hunters 
usually wait until after the spring bowhead whale hunt is finished 
before turning their attention to hunting belugas. The average annual 
harvest of beluga whales taken by Barrow for 1962-1982 was five (MMS, 
1996). The Alaska Beluga Whale Committee recorded that 23 beluga whales 
were 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, 1997; 
Alaska Beluga Whale Committee, 2002 in USDI/BLM, 2005). GXT states that 
it is possible, but unlikely, that accessibility to belugas during the 
subsistence hunt could be impaired during the survey. However, very 
little of the proposed survey is within 25 km (15.5 mi) of the Chukchi 
coast. That means the vessel will usually be well offshore away from 
areas where seismic surveys would influence beluga hunting by these 
communities.
    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, seismic surveys should not conflict 
with seal harvest activities.

Impact on Habitat

    The proposed seismic survey will not result in any long-term impact 
on habitats used by marine mammals, or to the food sources they 
utilize. Although feeding cetaceans and pinnipeds may occur in the 
area, the proposed activities will be of short duration in any 
particular area at any given time; thus any effects would be localized 
and short-term.
    One of the reasons for the adoption of airguns as the standard 
energy source for marine surveys was that, unlike explosives, they do 
not result in any appreciable fish kill. However, the existing body of 
information relating to the impacts of seismic on marine fish and 
invertebrate species, the primary food sources of pinnipeds and 
belugas, is very limited.
    In water, acute injury and death of organisms exposed to seismic 
energy depends primarily on two features of the sound source: (1) the 
received peak pressure, and (2) the time required for the pressure to 
rise and decay (Hubbs and Rechnitzer, 1952; Wardle et al., 2001). 
Generally, the higher the received pressure and the less time it takes 
for the pressure to rise and decay, the greater the chance of acute 
pathological effects. Considering the peak pressure and rise/decay time 
characteristics of seismic airgun arrays used today, the pathological 
zone for fish and invertebrates would be expected to be within a few 
meters of the seismic source (Buchanan et al., 2004).
    Therefore, NMFS has determined that the proposed Chukchi Sea 
seismic program for 2006 will have negligible physical effects on the 
various life stages of fish and invertebrates or have any habitat-
related effects that could cause significant or long-term consequences 
for individual marine mammals or their populations, since operations at 
any specific location will be limited in duration.

Mitigation Measures

    For the proposed seismic survey in the Chukchi Sea, GXT will deploy 
an airgun source composed of 36 sleeve airguns. The airguns comprising 
the array will be spread out horizontally, so that most the energy will 
be directed downward. GXT and NMFS believe that the directional nature 
of this array is an important factor for mitigating high energy sounds 
on marine mammals that are on or in near-surface waters. This 
directionality will result in reduced sound levels at any given 
horizontal distance compared to levels expected at that distance if the 
source were omnidirectional with the stated nominal source.
    Important mitigation factors built into the design of the survey 
include the fact that the spring migration and hunt for bowhead whales 
in Chukchi waters will be completed prior to the start of GXT's survey. 
Also, it is likely that many bowhead whales have already reached 
Russian waters north of the Chukotsk Peninsula when surveying is 
expected to resume in the autumn. Thus, the density of bowhead whales 
encountered during the fall in the Chukchi Sea, where the migration 
corridor becomes broad across the Chukchi, is expected to be much lower 
than that of the Beaufort Sea during the fall, where the migration 
corridor is narrow (Richardson and Thomson, 2002).
    Received sound fields were modeled by GXT for the 36-airgun 
configuration, in relation to distance and direction from the array. 
The distance from the array by which received levels would have 
diminished to 190, 180, 160 and other levels (in dB re 1 microPa rms) 
are likely to depend on water depth and location. Table 1 presents the 
predicted sound radii for the 36-airgun array in intermediate (200-500 
m (656-1640 ft)) water depths. The radii for deeper or shallower water 
are predicted by GXT to be smaller than those for intermediate depths.
    Empirical data concerning these radii are not yet available, but 
will be acquired prior to commencing the 2006 seismic field season. In 
addition to performing an acoustic characterization/verification of the 
full 36-airgun array at different depths, the output from a single 40 
in3 sleeve gun source will also be measured in order to determine the 
appropriate safety radius for use during power downs. A summary report 
on the acoustic measurements and proposed refinements to the safety 
radii will be made available for review shortly after the data have 
been collected. Until these empirical data are available, the 180- and 
190-dB radii predicted to be applicable to intermediate water depths 
(with a precautionary 1.5X adjustment) will also be applied for deep 
and shallow water operations when estimating the required safety radii. 
More detailed modeling of the airgun array may be completed prior to 
the beginning of the field season and the resulting 120-, 160-,180- and 
190-dB (rms) safety radii (with 1.5X factor) will be applied at the 
start of the season if that occurs.
    The following mitigation measures, as well as marine mammal visual 
monitoring (discussed later in this document), will be implemented for 
the subject seismic survey: (1) Speed and course alteration (provided 
that they do not compromise operational safety requirements); (2) 
power-down/shut-down procedures; and (3) ramp-up procedures.

Speed and Course Alteration

    If a marine mammal is detected outside its respective safety zone 
(180 dB for cetaceans, 190 dB for pinnipeds) and, based on its position 
and the relative motion, is likely to enter the safety zone, the 
vessel's speed and/or direct course may, when practical and safe, be 
changed to avoid the mammal in a manner that also minimizes the effect 
to the planned science objectives. The marine mammal activities and 
movements relative to the seismic vessel will be closely monitored to 
ensure that

[[Page 49429]]

the marine mammal does not enter the safety zone. If the mammal appears 
likely to enter the safety zone, further mitigative actions will be 
taken (i.e., either further course alterations or shut down of the 
airguns).

Power-down and Shut-down Procedures

    A power-down involves decreasing the number of airguns in use such 
that the radii of the 190-dB and 180-dB zones are decreased to the 
extent that observed marine mammals are not in the applicable 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 (or some other 
number of airguns less than the full airgun array) is operated. The 
continued operation of one airgun is intended to (a) alert marine 
mammals to the presence of the seismic vessel in the area, and (b) 
retain the option of initiating a ramp up to full operations under poor 
visibility conditions. In contrast, a shut down occurs when all airgun 
activity is suspended.
    If a marine mammal is detected outside the safety radius but 
appears 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 immediately if this is a 
reasonable alternative to a complete shut down. During a power-down of 
the 36-airgun array, the number of guns operating will be reduced to a 
single 40 in3 sleeve airgun. The 190-dB (rms) safety radius around the 
40 in3 airgun had not been modeled previously, but will empirically 
measured during acoustic verification measurements made at the start of 
seismic operations. If a marine mammal is detected within or near the 
smaller safety radius around the single 40 in3 sleeve airgun, all 
airguns will be shut down.
    Following a power-down, operation of the full airgun array 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 to have left the safety zone, or has not been seen within the 
zone for 15 minutes in the case of small odontocetes and pinnipeds, and 
for 30 minutes in the case of mysticetes (large odontocetes do not 
occur within the activity area).

Shut-down Procedures

    The operating airgun(s) will be shut down completely if a marine 
mammal approaches or enters the applicable safety radius and a power 
down is not practical or adequate to reduce exposure to less than 190 
or 180 dB (rms), as appropriate. The operating airgun(s) will also be 
shut down completely if a marine mammal approaches or enters the 
estimated safety radius around the reduced source (one 40 in\3\ sleeve 
gun) that will be used during a power down.
    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 as described previously. Ramp-up procedures will be 
followed during resumption of full seismic operations.

Ramp-up Procedure

    A ``ramp up'' or ``soft start'' procedure will be followed when the 
airgun array begins operating after a specified-duration period with no 
or reduced airgun operations. The specified period depends on the speed 
of the source vessel, the size of the airgun array that is being used, 
and the size of the safety radii, but is typically about 10 minutes or 
the time the vessel would reach the location of the 180-dB radius at 
the time of shut-down or power-down, whichever is greater.
    Ramp-up will likely begin with a single airgun (the smallest, or 40 
in\3\). The precise ramp-up procedure will be determined prior to 
start-up (based upon array configuration), but will proceed at a ramp-
up rate of no more than 6 dB per 5 min period. The standard industry 
procedure is to double the number of operating airguns at 5-minute 
intervals which is equal to about a 6 dB increase. During the ramp-up, 
the safety zone for the full 36-airgun array (or whatever smaller 
source might then be in use) will be maintained. If the complete 180-dB 
safety radius has not been visible for at least 30 minutes prior to the 
planned start of a ramp-up in either daylight or nighttime, ramp-up 
will not commence unless at least one airgun has been operating during 
that period. This means that it will not be permissible to ramp up the 
36-airguns from a complete shut down in thick fog, when the entire 180-
dB safety zone is not visible. If the entire safety radius is visible 
using vessel lights and/or night-vision devices (NVDs), then start up 
of the airguns from a complete 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 either be alerted by the sounds from the 
single airgun and could move away, or may be detected by visual 
observations. Given the responsiveness of bowhead and beluga whales to 
airgun sounds, it can be assumed that those species, in particular, 
will move away during a ramp-up.
    Ramp-up of the airguns will not be initiated during the day or at 
night if a marine mammal has been sighted within or near the applicable 
safety radius during the previous 15 minutes.

Mitigation for Subsistence Needs

    GXT has signed a Conflict Avoidance Agreement (CAA) for the 
proposed 2006 seismic survey in the Chukchi Sea, in consultation with 
representatives of communities along the Alaska coast including Pt. 
Hope, Pt. Lay, Wainwright, and Barrow. The signed CAA provides NMFS 
with information to make a determination that the activity will not 
have an unmitigable adverse impact on the subsistence use of marine 
mammals. GXT worked with representatives of these communities to 
identify and avoid areas of potential conflict, and provided a 
presentation at the AEWC mini-convention in Anchorage, Alaska, on 15 
March 2006. Meetings with AEWC and NSB representatives also occurred at 
the time of the convention. Also, GXT participated in the open water 
peer/stakeholder review meeting that was convened by NMFS in Anchorage 
on April 18-21, 2006, along with representatives of the AEWC and NSB.
    The signed CAA covers GXT's seismic survey planned to occur in the 
Chukchi Sea between July 1 and November 30, 2006. The purpose is to 
identify measures that will be taken to minimize any adverse effects on 
the availability of marine mammals for subsistence uses, and to ensure 
good communication between GXT (including the project leaders and the 
M/V Discoverer), native communities along the coast, and subsistence 
hunters at sea.
    The CAA also addresses the following: (1) operational agreement and 
communications procedures; (2) where/when agreement becomes effective; 
(3) general communications scheme; (4) on-board Inupiat observer; 
identification of seasonally sensitive areas; (5) vessel navigation; 
(6) air navigation; (7) marine mammal monitoring activities; (7) 
measures to avoid impacts to marine mammals; (8) measures to avoid 
conflicts in areas of active whaling; (9) emergency assistance; and 
(10) dispute resolution process.
    In the unlikely event that subsistence hunting or fishing is 
occurring within 5 km (3 mi) of the M/V Discoverer's

[[Page 49430]]

trackline, or in other situations inconsistent with the CAA, the airgun 
operations will be suspended until the vessel is greater than 5 km (3 
mi) away and otherwise in compliance with the CAA.

Monitoring

    GXT will implement a marine mammal monitoring program during the 
present project, in order to implement the mitigation measures that 
require real-time monitoring, to satisfy the anticipated monitoring 
requirements of the NMFS and USFWS IHAs, and to meet any monitoring 
requirements agreed to as part of the CAA. The monitoring work 
described here has been planned as a self-contained project independent 
of any other related monitoring projects that may be occurring 
simultaneously in the same regions.

Vessel-based Visual Monitoring

    Vessel-based observers will monitor marine mammals near the seismic 
source vessel during all daytime hours and during any power ups of the 
airgun(s) at night. Airgun operations will be powered down or (if 
necessary) shut down when marine mammals are observed within, or about 
to enter, designated safety radii. Vessel-based marine mammal observers 
(MMOs) will also watch for marine mammals near the seismic vessel for 
at least 30 minutes prior to the planned start of airgun operations and 
after any shut downs of the airgun array that do not have at least 30 
minutes of continuous marine mammal observations prior to start-up. 
When feasible, observations will also be made during daytime periods 
without seismic operations (e.g., during transits).
    During seismic operations when there is 24 hrs of daylight, four 
observers will be based aboard the vessel. As the number of hours of 
daylight decreases in the fall, the number of MMOs on the vessel will 
be reduced to three MMOs. MMOs will be appointed by GXT with NMFS and 
USFWS concurrence. An Alaska native resident knowledgeable about the 
mammals and fish of the area is expected to be included as one of the 
team of MMOs aboard the M/V Discoverer. At least one observer, and when 
practical two observers, will monitor marine mammals near the seismic 
vessel during ongoing daytime operations and any nighttime start ups of 
the airguns. (There will be no periods of total darkness until mid-
August.) Use of two simultaneous observers will increase the proportion 
of the animals present near the source vessel that are detected. MMOs 
will be on duty in shifts of duration no longer than 4 hours. The M/V 
Discoverer crew will be instructed by the MMOs onboard 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 by the MMOs regarding implementation of 
mitigation measures.
    The M/V Discoverer is a suitable platform for marine mammal 
observations. Observations will be made from either the bridge or the 
flying bridge, which are greater than 12 m (40 ft) above sea level. 
From the bridge, about 45[deg] of the view will be obstructed directly 
to the stern. During daytime, the MMO(s) will scan the area around the 
vessel systematically with reticle binoculars (e.g., 7 50 Fujinon), and 
with the naked eye. During any periods of darkness, NVDs will be 
available (ITT F500 Series Generation 3 binocular-image intensifier or 
equivalent), if and when required. Laser rangefinding binoculars (Leica 
LRF 1200 laser rangefinder or equivalent) will be available to assist 
with distance estimation; these are useful in training observers to 
estimate distances visually, but are generally not useful in measuring 
distances to animals directly.
    When marine mammals in the water are detected within or about to 
enter the designated safety radius, the airgun(s) will be powered down 
or shut down immediately. To assure prompt implementation of shut 
downs, multiple channels of communication between the MMOs and the 
airgun technicians will be established. During power downs and shut 
downs, the MMO(s) will continue to maintain watch to determine when the 
animal(s) are outside the safety radius. Airgun operations will not 
resume until the animal is outside the safety radius. Marine mammals 
will be considered to have cleared the safety radius if they are 
visually observed to have left the safety radius, or if they have not 
been seen within the radius for 15 minutes (pinnipeds and small 
cetaceans) or for 30 minutes (large cetaceans).
    All observations and airgun power downs or 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 power or shut down), (2) 
information needed to estimate the number of marine mammals potentially 
taken by harassment, (3) data on the occurrence, distribution, and 
activities of marine mammals in the area where the seismic study is 
conducted, (4) information to compare the distance and distribution of 
marine mammals relative to the source vessel at times with and without 
seismic activity, and (5) data on the behavior and movement patterns of 
marine mammals seen at times with and without seismic activity.

Acoustic Verification and Modeling

    Measurements of received sound levels as a function of distance and 
direction from the proposed airgun arrays will be made prior to 
beginning the seismic survey. Results of this acoustic 
characterization/verification will be used to refine the pre-season 
estimates of safety and disturbance radii applicable to the sources 
during the remainder of seismic operations. A preliminary report of the 
measurement results concerning the 190-dB and 180- dB (rms) safety 
radii will be submitted shortly after data collection.
    Additionally, more extensive modeling of the sounds that will be 
produced by the airgun array may be completed prior to the field 
season. The results of this modeling, if done, will be made available 
before the field season and the safety radii adjusted accordingly.
Additional Mitigation and Monitoring Measures
    As part of NMFS' week-long open-water meeting in Anchorage, on 
April 19-20, 2006, participants had a discussion on appropriate 
mitigation and monitoring measures for Arctic Ocean seismic activities 
in 2006. In addition to the standard mitigation and monitoring 
measures, additional measures, such as expanded monitoring-safety zones 
for bowhead and gray whales, and having those zones monitored 
effectively, have been implemented in order for NMFS to meet its 
requirements under NEPA. The additional mitigation measures reviewed 
here are specific for this project. They do not establish NMFS policy 
applicable to other projects or other locations under NMFS' 
jurisdiction, as each application for an IHA is context dependent, that 
is, judged independently as to which measures are practicable and 
necessary to reduce impacts to the lowest level and to ensure that 
takings do not have

[[Page 49431]]

an unmitigable adverse impact on subsistence uses. These measures have 
been developed based upon available data specific to the project areas. 
NMFS and MMS intend to collect additional information from all sources, 
including industry, non-governmental organizations, Alaska Natives and 
other federal and state agencies regarding measures necessary for 
effectively monitoring marine mammal populations, assessing impacts 
from seismic on marine mammals, and determining practicable measures 
for mitigating those impacts. MMS and NMFS anticipate that mitigation 
measures applicable to future seismic and other activities may change 
and evolve based on newly-acquired data.

Research

    GXT, Shell and ConocoPhillips have developed, and will implement, a 
joint-research component to their individual marine mammal monitoring 
programs that will further improve the understanding of impacts of 
seismic exploration on marine mammals, particularly bowhead whales. A 
preliminary description of this research was outlined in NMFS' proposed 
notice (71 FR 32045, June 6, 2006). Following NMFS' open water meeting 
in Anchorage, AK on April 19-24, 2006, a more detailed research plan 
was developed for the seismic industry. The latest version of this 
report is available for downloading (see ADDRESSES). This plan 
includes:
    Vessel-based Surveys: MMOs will conduct observations onboard a 
dedicated vessel conducting at least three individual surveys early in 
the seismic season, in the middle of the season and late in the season, 
as well as opportunistic surveys while the vessel is being used for 
crew changes/supply runs. The survey will systematically cover broad 
areas of the Chukchi planning area in order to obtain adequate coverage 
across multiple habitat types (subject to vessel operational 
limitations near ice pack). The surveys will provide: (1) quantitative 
data on distribution and densities for each marine mammal species by 
habitat (depth and ice); (2) sighting data to compute densities during 
seismic and non seismic periods; (3) density information during non-
seismic periods to be used to estimate numbers of marine mammals that 
would have been exposed to various sound levels (160, 180, 190 dB re 1 
microPa), if they had not moved away from the seismic vessel; and (4) 
sighting and density information from operating seismic vessel will 
provide data on numbers that did not avoid the vessel and were exposed 
to the same sound levels.
    Passive Acoustic Monitoring (PAM): 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 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 
daylight hours by at least one bioacoustician. Sightings rates, and 
depending on the amount of data collected, the densities of marine 
mammals in the survey area will be estimated during the three surveys. 
Most likely the R/V Torsvik, the dedicated marine mammal monitoring 
vessel will tow the PAM.
    Chukchi Sea Coastal Aerial Survey: An aerial survey program will be 
conducted in support of the seismic programs in the Chukchi Sea during 
summer and fall of 2006. The objectives of the aerial survey will be: 
(1) to address data deficiencies in the distribution and abundance of 
marine mammals in coastal areas of the eastern Chukchi Sea; and (2) to 
collect and report data on the distribution, numbers, orientation and 
behavior of marine mammals, particularly beluga whales, near 
traditional hunting areas in the eastern Chukchi Sea.
    Acoustic ``Net'' Array: A suite of autonomous seafloor recorders 
(pop-ups) will be deployed to collect acoustic data from strategically 
situated sites in the Chukchi Sea. The basic plan is 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 four 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 four pop-ups will be deployed at sites about 50-
75 nm (93-139 km) offshore. The acoustic ``net'' array has been 
designed to accomplish two main objectives: (1) to collect information 
on the occurrence and distribution of beluga whales that may be 
available to subsistence hunters near villages located on the Chukchi 
Sea coast, and (2) to measure the ambient noise levels near these 
villages and record received levels of sounds from seismic survey 
activities should they be detectable.

Reporting

    During the field season, brief bi-weekly progress reports on the 
status of the activity and level of marine mammal interactions will be 
submitted. A report on the preliminary results of the acoustic 
verification measurements, including as a minimum the measured 180- and 
190-dB (rms) radii of the airgun sources, will be submitted shortly 
after collection and analysis of those measurements at the start of the 
field season. This report will specify the refinements to the safety 
radii that are proposed for adoption.
    A report on GXT's seismic activities and on the relevant monitoring 
and mitigation results will be submitted to NMFS within 90 days after 
the end of the Chukchi sea seismic work. The report will provide full 
documentation of methods, results, and interpretation pertaining to all 
acoustic characterization work and vessel-based monitoring. The 90-day 
report will summarize the dates and locations of seismic operations, 
and all cetacean and seal sightings (dates, times, locations, 
activities, associated seismic survey activities). The number and 
circumstances of ramp-ups, power-downs, shutdowns, and other mitigation 
actions will be reported. The report will also include estimates of the 
numbers of mammals affected and the nature of observed impacts on 
cetaceans and seals.
    Following the 2006 open water season, a single comprehensive report 
describing the acoustic, vessel-based, and aerial monitoring programs 
for all industrial seismic programs 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

[[Page 49432]]

types of acoustic systems for data collection, 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.

ESA

    NMFS has issued a biological opinion regarding the effects of this 
action 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).

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 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 that issuance by NMFS of an IHA to GXT 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.
    This determination is predicated 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 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. These mitigation 
measures were incorporated into NMFS' Selected Alternative and IHA 
conditions for this year's seismic survey operations. Accordingly, NMFS 
adopts MMS' Final PEA and has determined that the preparation of an 
Environmental Impact Statement for this action is not necessary. A copy 
of the MMS Final PEA for this activity is available upon request and is 
available online (see ADDRESSES).

Essential Fish Habitat (EFH)

    The action area has been identified and described as EFH for 5 
species of Pacific salmon (pink (humpback), chum (dog), sockeye (red), 
chinook (king), and coho (silver)) occurring in Alaska. The issuance of 
this proposed incidental harassment authorization is not anticipated to 
have any adverse effects on EFH, and therefore no consultation is 
required.

Determinations

Summary

    Based on the information provided in GXT's application and the MMS 
Final PEA, NMFS has determined that GXT's seismic surveys in the 
northern Chukchi Sea in 2006 will have a negligible impact on the 
affected species or stocks of marine mammals, result in the taking of 
small numbers of marine mammals, and will not have an unmitigable 
adverse impacts on their availability for taking for subsistence uses, 
provided the mitigation and monitoring measures required under the IHA 
are implemented and the POC/CAA is implemented.

Potential Impacts on Marine Mammals

    NMFS has determined that the impact of conducting relatively short-
term seismic surveys in the U.S. Chukchi Sea may result, at worst, in a 
temporary modification in behavior by certain species of marine 
mammals. While behavioral and avoidance reactions may occur in response 
to the resultant seismic noise and vessel appearance, 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 in the area 
of seismic operations, which will vary annually due to variable ice 
conditions and other factors, the number of potential harassment 
takings is estimated to be small relative to the population estimates 
(see Table 2 in this document).
    In addition, no take by death or serious injury is anticipated, and 
the potential for temporary or permanent hearing impairment will be 
avoided through the incorporation of the mitigation measures proposed 
for GXT's IHA. 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 (especially bowhead, gray, and beluga 
whales in Arctic waters) are expected to move away from seismic noise 
that is annoying prior to its becoming potentially injurious; (2) 
recent research that indicates that TTS is unlikely at SPLs as low as 
180 dB re 1 microPa; (3) the fact that injurious levels would be 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 seismic vessel. Finally, 
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 proposed seismic activity by GXT in the 
northern Chukchi Sea in 2006, in combination with other seismic and oil 
and gas programs in this area, 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 the spring 
bowhead hunt is expected to have ended; (2) the CAA conditions should 
significantly reduce impacts on subsistence hunters; (3) while it is 
possible that accessibility to belugas during the spring subsistence 
beluga hunt could be impaired by the survey, it is unlikely because 
little to none of GXT's proposed survey is within 25 km (15.5 mi) of 
the Chukchi coast, meaning the vessel will usually be well offshore

[[Page 49433]]

and away from areas where seismic surveys would influence beluga 
hunting by communities; and (4) 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 where 
natives would harvest these seals, it should not conflict with harvest 
activities.

Authorization

    As a result of these determinations, NMFS has issued an IHA to GXT 
to take small numbers of marine mammals, by harassment, incidental to 
conducting a seismic survey in the northern Chukchi Sea in 2006, 
provided the mitigation, monitoring, and reporting requirements 
described in this document are undertaken.

    Dated: August 15, 2006.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 06-7097 Filed 8-22-06; 8:45 am]
BILLING CODE 3510-22-S