[Federal Register Volume 78, Number 161 (Tuesday, August 20, 2013)]
[Notices]
[Pages 51147-51169]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-20310]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC563


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Marine Seismic Survey in the 
Chukchi Sea, Alaska

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

ACTION: Notice; issuance of an incidental take authorization.

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SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) 
regulations, notification is hereby given that NMFS has issued an 
Incidental Harassment Authorization (IHA) to TGS-NOPEC Geophysical 
Company ASA (TGS) to take, by harassment, small numbers of marine 
mammals incidental to a marine 2-dimensional (2D) seismic survey 
program in the Chukchi Sea, Alaska, during the 2013 Arctic open-water 
season.

DATES: Effective August 14, 2013, through October 31, 2013.

ADDRESSES: Inquiry for information on the incidental take authorization 
should be addressed to P. Michael Payne, Chief, Permits and 
Conservation Division, Office of Protected Resources, National Marine 
Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910. A 
copy of the application containing a list of the references used in 
this document, NMFS' Environmental Assessment (EA), Finding of No 
Significant Impact (FONSI), and the IHA may be obtained by writing to 
the address specified above, telephoning the contact listed below (see 
FOR FURTHER INFORMATION CONTACT), or visiting the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    Documents cited in this notice may be viewed, by appointment, 
during regular business hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected 
Resources, NMFS, (301) 427-8401 or Brad Smith, NMFS, Alaska Region, 
(907) 271-3023.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of 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.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``. . . an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the U.S. can apply for an authorization to 
incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS review of 
an application followed by a 30-day public notice and comment period on 
any proposed authorizations for the incidental harassment of marine 
mammals. Within 45 days of the close of the comment period, NMFS must 
either issue or deny the authorization.
    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''].

Summary of Request

    On December 3, 2012, NMFS received an application from TGS 
requesting an authorization for the harassment of small numbers of 
marine mammals incidental to conducting an open-water 2D seismic survey 
in the Chukchi Sea off Alaska. After addressing comments from NMFS, TGS 
modified its application and submitted a revised application on April 
1, 2013, and a revised marine mammal monitoring and mitigation plan on 
April 15, 2013, with additional clarification on May 7, 2013. TGS' 
activities discussed here are based on its April 1, 2013, IHA 
application and April 15, 2013, marine mammal monitoring and mitigation 
measures.

Description of the Specified Activity

    TGS proposes to conduct approximately 9,600 km of marine 2D seismic 
surveys along pre-determined lines in U.S. waters and international 
waters of the Chukchi Sea (Figure 1 of TGS' IHA application) during the 
2013 open water season. The purpose of the seismic program is to gather 
geophysical data using a 3,280 in\3\ seismic source array and an 8,100-
m long hydrophone solid streamer towed by the seismic vessel. Results 
of the 2D seismic program would be used to identify and map potential 
hydrocarbon-bearing formations and the geologic structures that 
surround them.
    Approximately 35 days of seismic operations are expected to occur 
over a period of about 45-60 days in U.S. Chukchi Sea. In addition, up 
to 33 days of seismic operations may occur in international waters 
(depending on ice and weather conditions). Seismic operations are 
proposed to occur along pre-determined track lines at speeds of about 
four to five knots. Seismic operations would be conducted up to 24 
hours per day as possible except as potentially needed for shut-down 
mitigation for marine mammals. The full 3,280 in\3\ airgun array would 
only be firing during seismic acquisition operations on and near the 
end and start of survey lines; during turns and transits between 
seismic lines, a single ``mitigation'' airgun (60 in\3\ or smaller) is 
proposed to be operated.
    Two vessels would be used during the survey: (1) a seismic 
operations vessel that would tow the seismic source array hydrophone 
solid streamer, and (2) a

[[Page 51148]]

smaller vessel that will be used to search for marine mammals and scout 
for ice and other navigation hazards ahead of the seismic vessel. In 
the event of an emergency, the scout vessel may be used to support the 
seismic vessel. In this extraordinary circumstance, all seismic 
activity will cease since the scout vessel will no longer be devoted to 
monitoring the exclusion zones.
    The seismic vessel will tow a compressed-air seismic source array 
of 28 Bolt 1900 LLXT airguns with a total discharge volume of 3,280 
in\3\. The airguns range in volume from 40 in\3\ to 300 in\3\ and are 
arranged in a geometric lay-out of three sub-arrays that will be towed 
approximately 200 m behind the vessel at a depth of 6 m. The seismic 
source would discharge every 25 m (82 ft) or approximately every 10 
seconds. Additional details regarding seismic acquisition parameters 
are provided in TGS' IHA application. To ascertain whether the seismic 
source array is operating correctly, the full volume will be enabled 
for 1 km from the start of every line (i.e., a run in). To ensure full 
fold data acquisition the vessel will require a 4 km run out at the 
conclusion of each line. TGS states that gravity and magnetic data will 
also be passively acquired during the survey by measuring gravity and 
magnetic variations while traversing the lines (no acoustics are 
involved with these methods).
    The acoustic source level of the proposed 3,280 in\3\ seismic 
source array was predicted using JASCO's airgun array source model 
(AASM) based on data collected from three sites chosen in the project 
area by JASCO. Water depths at the three sites were 17, 40, and 100 m. 
JASCO applied its Marine Operations Noise Model (MONM) to estimate 
acoustic propagation of the proposed seismic source array and the 
associated distances to the 190, 180 and 160 dB (rms) re 1 [mu]Pa 
isopleths. The resulting isopleths modeled for the 180 and 190 dB (rms) 
re 1 [mu]Pa exclusion zone distances for cetaceans and pinnipeds, 
respectively, differed with the three water depths. An additional 10 
percent distance buffer was added by JASCO to these originally modeled 
distances to provide larger, more protective exclusion zone radii 
distances that will be adhered to during the project (Table 1).
    The estimated distances to the 190, 180 and 160 dB re 1[mu]Pa (rms) 
isopleths for the single 60 in\3\ airgun (the largest single airgun 
that would be used as a ``mitigation'' gun) were measured by JASCO 
during a monitoring sound source verification (SSV) study conducted for 
Statoil in 2010 in the Chukchi Sea during the open water season of 2010 
(Blees et al. 2010). Results indicated that the distance to the 190 dB 
isopleth was 13 m, the 180 dB isopleth distance was 68 m, and the 160 
dB isopleth distance was 1,500 m (all dB (rms) re 1 [mu]Pa).

Table 1--Modeled Distances in (Meters) to Received Sound Levels for the TGS' 3,280 in \3\ Airgun Array in Waters
                                 With Three Different Depths in the Chukchi Sea
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                                                     Received sound level (dB re 1 [mu]Pa rms)
        Water depths (m)         -------------------------------------------------------------------------------
                                          190                      180                           160
----------------------------------------------------------------------------------------------------------------
17-40...........................  930...............  2,200.......................  8,500
40-100..........................  920...............  2,500.......................  9,900
>100............................  430...............  2,400.......................  15,000
----------------------------------------------------------------------------------------------------------------

    Both vessels would use industry-standard echosounder/fathometer 
instruments to continuously monitor water depth for navigation purposes 
while underway. These instruments are the same as those used aboard all 
large vessels to obtain information on water depths and potential 
navigation hazards for vessel crews during routine navigation 
operations. Navigation echosounders direct a single, high-frequency 
acoustic signal that is focused in a narrow beam directly downward to 
the sea floor. The reflected sound energy is detected by the 
echosounder instrument which then calculates and displays water depth 
to the user. Typical source levels of these types of navigational 
echosounders are generally 180-200 dB re 1 [mu]Pa at 1 m.
    One navigational echosounder would be used by the seismic vessel 
and another one will be used by the scout vessel. The echosounder used 
by the seismic vessel will consist of a downward-facing single-beam 
(Kongsberg EA600) that operates at frequencies of 18 to 200 kHz (output 
power 1-2 kilowatt [kW]). Associated pulse durations are 0.064 and 
4.096 milliseconds (ms) long and repetition frequency of the pulse 
(i.e., the ping rate) is related to water depth. In shallow water, the 
highest pulse repetition frequency is about 20 pings per second. The 
scout vessel will use a Furuno 292 echosounder that operates at a 
frequency of 28 and 88 kHz. The highest ping rate in shallow water is 
12 pings per second.

Dates, Duration and Action Area

    TGS plans to conduct its 2D seismic surveys in both the U.S. 
Chukchi Sea and international waters through October 31, 2013. Seismic 
operations are anticipated to occur for about 35 days over a period of 
45-60 days in U.S. waters and up to about 33 days in international 
waters. Operations in U.S. waters are expected to be complete no later 
than October 5, 2013. However, poor weather, ice conditions, equipment 
repair, etc., would likely delay or curtail operations. Thus, this 
extended period allows flexibility in proposed operational dates, 
contingent on such conditions. Specific dates and durations of project 
activities are listed below in chronological order, but are contingent 
on weather and ice, etc.
    The seismic operations are proposed to occur in U.S. and 
international waters of the Chukchi Sea between about 70-77[deg] N and 
154-165[deg] W (Figure 1 of TGS' IHA application). Up to approximately 
6,088 km of seismic operations with the full sound source are planned 
to be conducted in U.S. waters as follows, which include 5,973 km of 
pre-plot lines plus approximately 115 km for 1-km run-in and 5-km run-
out between seismic lines. In addition, approximately 1,556 km with the 
single 60 in\3\ (or smaller) mitigation airgun are planned to be 
conducted during turns and transits between lines. Approximately 3,691 
km of seismic operations with the full seismic source as follows are 
planned to be conducted in international waters, which include 3,631 km 
of pre-plot lines plus about 60 km of 1-km run-in and 5-km run-out 
between pre-plot lines. In addition, approximately 812 km with the 
single 60 in\3\ (or smaller) mitigation airgun are planned to be 
conducted during turns and transits between seismic lines. Most of the 
total approximately 9,600 km of seismic lines occur in water 40-100 m 
deep (82% or 7,890 km), followed by waters >100 m deep (14% or 1,320 
km) and waters <40 m deep (4% or 390 km).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to TGS was published in 
the Federal Register on June 12, 2013 (78 FR 35508). That notice 
described, in

[[Page 51149]]

detail, TGS' activity, the marine mammal species that may be affected 
by the activity, and the anticipated effects on marine mammals and the 
availability of marine mammals for subsistence uses. During the 30-day 
public comment period, NMFS received three comment letters from the 
following: the Marine Mammal Commission (Commission); the Alaska Eskimo 
Whaling Commission (AEWC); the North Slope Borough; the Alaska 
Wilderness League (AWL), Center for Biological Diversity, Earthjustice, 
Greenpeace, International Fund for Animal Welfare, Natural Resources 
Defense Council, Northern Alaska Environmental Center, Ocean 
Conservation Research, Oceana, Redoil, and Sierra Club (collectively 
``AWL''), and two private citizens.
    Any comments specific to TGS' application that address the 
statutory and regulatory requirements or findings NMFS must make to 
issue an IHA are addressed in this section of the Federal Register 
notice.

Impacts Analysis

    Comment 1: A private citizen states that NMFS may not issue the IHA 
because it kills marine animals.
    Response: As discussed in detail in the Federal Register notice for 
the proposed IHA and in this document, the potential effects to marine 
mammals from TGS' 2D seismic surveys would be Level B behavioral 
harassment of small numbers of marine mammals in the project vicinity, 
and no injury, serious injury, or mortality is expected. In addition, 
no injury, serious injury, or mortality to marine mammal is authorized 
by NMFS under this IHA.
    Comment 2: The AEWC noted that on page 35516 of the Federal 
Register notice for the proposed IHA, NMGS stated that ``though 
temporary diversions of the swim path of migrating whales have been 
documented, the whales have generally been observed to resume their 
initial migratory route.'' The AEWC argues that there is no research 
support migrating bowhead whales return to their normal migratory path 
following deflection.
    Response: NMFS acknowledges that the above statement made in the 
Federal Register notice was somewhat misleading. NMFS has corrected the 
statement to read ``though temporary diversions of the swim path of 
migrating whales have been documented, the whales have generally been 
observed to continue their migration via a deflected migratory route.''
    Comment 3: The AEWC states that NMFS also needs to point out the 
potential for whales to become skittish--changing their swim speeds, 
breathing rates, and other migratory behavior--when affected by the 
proposed open-water seismic surveys and vessel noise, even when they do 
not deflect from their migratory path.
    Response: NMFS is aware of the potential effects of whales becoming 
skittish when exposed to seismic surveys and vessel noise, and has 
incorporated this information in this document.
    Comment 4: The NSB states that the distances estimated for the 190 
and 180 dB zones seem reasonable but the 160 dB zone may be 
substantially low. The NSB points out that previous sound source 
verifications (SSV) conducted in the Chukchi Sea measured distances of 
~ 8,000 to ~ 13,500 m for the 160 dB zone in similar water depths as 
proposed by TGS. The NSB requests that NMFS require applicants to 
provide data from previous SSV tests in future applications, even those 
conducted by other companies, as a check on the modeled estimates. The 
NSB further states that NMFS should require TGS to provide some sort of 
estimate of the possible variability in distances for each of the 
isopleths.
    Response: As stated in the Federal Register notice for the proposed 
IHA, as well as in TGS' IHA application, the acoustic source levels of 
the seismic source array and mitigation airgun were calculated using 
JASCO's airgun array source model (AASM) based on data collected from 
three sites chosen in the project area reported in SSV for Statoil in 
2010 by JASCO (see TGS' IHA application Appendix C). Water depths at 
the these three sites were 17, 40, and 100 m, and the modeled 160 dB 
zones range from 8,500 to 15,000 m. The possible variability in 
distances for the isopleths has been considered and the originally 
modeled exclusion zones were expanded by 10 percent by JASCO to provide 
larger, more protective exclusion zones.
    Comment 5: The Commission requests NMFS provide stronger assurance 
that the actual numbers of takes would be negligible by revising the 
estimates to (1) incorporate some measure of uncertainty in that 
estimate (e.g., upper and lower confidence limits) or (2) use maximum 
estimated densities. The AWL also claims that NMFS density estimations 
are arbitrary, and that maximum estimated densities should be used.
    Response: As discussed in detail in the Federal Register notice for 
the proposed IHA, TGS' 2D seismic survey areas include the U.S. Chukchi 
Sea and the international waters north of 72[deg] N, where marine 
mammal density is less certain, primarily due to lack of systematic 
scientific surveys. Therefore, density estimates for the proposed 
seismic survey area were based on two types of sources: (1) Dedicated 
marine mammal abundance surveys for certain areas and species, and (2) 
sightings of marine mammals observed from prior seismic surveys when 
seismic airgun arrays were off. The latter data were used to calculate 
marine mammal densities for areas with high uncertainties (because of 
the lack of well designed, dedicated marine mammal surveys). Since 
these latter data were based on a few opportunistic sightings, it was 
not possible to perform a rigorous statistical analysis and derive 
upper and lower confidence limits. In fact, some of these densities in 
the north of 72[deg] N were actually based on marine mammal densities 
south of 72[deg] N, which is considered protective because it over-
estimates take numbers.
    In this case, NMFS has chosen to use the average density data of 
marine mammal populations to calculate estimated take numbers because 
these numbers are based on dedicated surveys and monitoring of marine 
mammals in the vicinity of the proposed project area. ``Maximum 
densities'' are typically the average densities multiplied by a factor 
of 4 or 5, and the method of their derivation is not scientifically 
justified and would likely result in an overestimate. For several 
species whose average densities are too low to yield a take number due 
to extra-limital distribution in the vicinity of the proposed Chukchi 
Sea survey area, but whose chance occurrence has been documented in the 
past, such as killer whales, narwhales, and harbor porpoises, NMFS 
allotted a few numbers of these species to allow unexpected takes.
    The negligible determination is based on analysis of the potential 
effects of the specific activities (i.e., airgun impulses from TGS' 2D 
seismic surveys) on marine mammals, as well as the effectiveness of the 
required monitoring and mitigation measures to minimize such effects. 
Although different marine mammal densities used for take calculation 
may yield different take numbers, the result is not likely to change 
the nature of potential effects. In addition, an inflated take number 
based on ``maximum densities'' could lead to more takes being 
authorized. Finally, based on prior year marine mammal monitoring 
reports from Arctic seismic surveys, it is well documented that the 
numbers of marine mammals (modeled and corrected to account for animals 
not observed) exposed to noise levels above harassment thresholds were 
always

[[Page 51150]]

lower than take numbers calculated based on average densities.
    Comment 6: The NSB states that beluga whales from both the Chukchi 
Sea stock and Beaufort Sea stock will be found in TGS' proposed seismic 
survey area. The NSB further points out that the Chukchi Sea stock will 
certainly be there throughout the summer and the Beaufort Sea stock 
will migrate through the Chukchi Sea during autumn migration in 
September and October. The NSB states that it is unlikely that PSOs 
will see belugas from the vessels because the animals are very 
sensitive to anthropogenic sounds. The NSB states that TGS should be 
required to have a monitoring technique that will allow them to observe 
belugas in the far field (i.e., beyond the visual observers view). In 
addition, citing TGS' IHA application, the NSB points out that although 
it is true that most observations of belugas tend to be near the shore, 
the entire Beaufort Sea stock of beluga whales migrates south through 
the Chukchi Sea. The NSB further states that satellite tagged belugas 
from the Beaufort Sea stock migrate south through the Chukchi Sea far 
offshore in some cases.
    Response: While the Beaufort Sea stock beluga whales do migrate 
through the Chukchi during their fall migration, NMFS considers it 
unlikely TGS would encounter this population during its open-water 
seismic survey because of the temporal and spatial design of the 
survey. TGS plans on surveying the Alaskan Chukchi first in August when 
the Beaufort Sea stock beluga whales will be in their Beaufort Sea 
summer area. Although recent tagging studies showed that Beaufort Sea 
stock beluga whales migrate through deep water during their fall 
westward migration, the majority of the animals are expected to stay 
below 72[deg] N in September (Hauser et al. 2013). In October, most 
Beaufort Sea beluga whales will have moved farther south/west along the 
Russian Chukchi Sea (Hauser et al. 2013). The TGS survey area during 
September and October will be moved farther north offshore in 
international waters above 72[deg] N. Therefore, it is not likely the 
survey would encounter Beaufort Sea stock beluga whales during the 
latter portion of the surveys.
    Regarding far field monitoring of marine mammals, as stated in the 
Federal Register notice for the proposed IHA, visual monitoring from a 
scout vessel at the perimeter of the exclusion zone as well as towed 
passive acoustic monitoring will be implemented.
    Comment 7: Citing TGS' IHA application that harbor porpoises are 
unlikely to occur in significant numbers within the seismic survey 
area, the NSB argues that this is a misstatement. Citing Industry's 
Joint Monitoring Program Reports for the Chukchi and Beaufort Seas and 
90-day monitoring reports since 2006, the NSB points out that in recent 
industry surveys, harbor porpoises are one of the most commonly seen 
cetaceans in the Chukchi Sea. The NSB further points out that harbor 
porpoises are among the most commonly sighted cetaceans in Table 3 of 
TGS' IHA application. The NSB states that TGS must consider this 
cetacean in their assessment of possible impacts to marine mammals from 
the proposed seismic survey.
    Response: While NMFS does not disagree with the NSB assessment 
regarding the occurrence of harbor porpoises in Chukchi Sea, it is also 
important to note that the area where harbor porpoise occurrences were 
recorded in the Industry's Joint Monitoring Program Report for the 
Chukchi and Beaufort Seas are limited to within the U.S. Beaufort Sea, 
while much of TGS' proposed 2D seismic survey area is located in 
international waters farther north and offshore, which is not likely a 
habitat for the harbor porpoise, which occur more often inshore. 
Further, while TGS may have inaccurately characterized the abundance of 
harbor porpoises in the U.S. Chukchi Sea, where part of its 2D seismic 
surveys would occur, NMFS conducted its own analyses in determine the 
potential impacts to all marine mammal species within both U.S. Chukchi 
Sea and international waters. Finally, as the NSB also noticed, the 
harbor porpoise densities presented in Table 3, which were used to 
calculate take estimates, actually used information from 90-day 
monitoring reports submitted in prior years by holders of incidental 
take authorizations, and took into consideration the high occurrence of 
this species in the U.S. Chukchi Sea.
    Comment 8: Citing TGS' IHA application, the NSB points out that 
TGS' statement that its activities are ``expected to be temporary and 
minor, with no long-term impacts to individuals or populations based on 
available studies'' is misleading. The NSB pointed out that no one has 
examined the long-term effects from seismic exposure; therefore no data 
exist to evaluate the long-term effects.
    Response: NMFS agrees with the NSB's assessment that the long-term 
effects on marine mammals from seismic surveys are still largely 
unknown, therefore, the statement made by TGS in its IHA application 
needs to be viewed with caution. Nevertheless, in making the 
determination to issue the IHA to TGS, NMFS conducted its own analyses 
and evaluation. A more detailed discussion on potential anthropogenic 
noise impacts on marine mammals and marine mammal habitat can be found 
in the Federal Register notice for the proposed IHA, as well as in this 
document.
    Comment 9: The Commission requests that NMFS require TGS to revise 
its take estimates such that adjustment factors do not reduce the 
estimated densities for waters north of 72[deg] N latitude without 
additional scientific basis for those adjustments. The NSB also pointed 
out that satellite tagging of beluga whales indicated many of the 
whales traveled to north of 72[deg] N. The NSB questions how TGS is 
going to monitor and assess possible impacts to beluga whales.
    Response: NMFS believes that this comment is due to the language 
presented in TGS' original IHA application. The initial IHA application 
submitted by TGS in November 2012 contained an adjustment factor of 
0.01 for gray whales, 0.10 for bowhead and beluga whales, and ringed 
and bearded seals for areas above 72[deg] N. This IHA application, 
though not published for public comment as NMFS did not consider it 
complete, was submitted to a peer review panel, which included members 
from the Commission and the NSB, for review and comment. After 
receiving NMFS comments and recommendations, TGS subsequently modified 
its analysis and submitted a revised IHA application on April 1, 2013. 
The revised IHA application included ``upper-adjusted density 
estimates'', which is virtually the same adjustment proposed in TGS' 
initial IHA application, and ``lower-adjusted density estimates'', 
which only make an adjustment for gray whales north of 72[deg] N by a 
factor of 0.2. No adjustments were made for bowhead and beluga whales 
and bearded and ringed seals north of 72[deg] N.
    In NMFS calculation of take estimates, the ``lower-adjusted density 
estimates'' were used for adjusting the gray whale numbers because 
reported gray whale distribution in the Chukchi Sea normally does not 
extend much north of 72[deg] N during summer/fall (Clarke and Ferguson 
2010). This northernmost peripheral boundary area is thus expected to 
have very low gray whale densities. In addition, by fall when TGS 
enters into the international waters after completing surveys in the 
U.S. Chukchi Sea, most gray whales will have migrated south of the 
project area north of 72[deg] N (Rice and Wolman 1971; Allen and 
Angliss 2011).

[[Page 51151]]

    Comment 10: The NSB states that Table 4 of TGS' IHA application 
showed that all adjustments would lower the densities of marine mammals 
north of 72[deg] N as all the values are <=1. The NSB also notes that 
the footnote (*) suggests the densities may increase but because the 
factors are one or less the densities will all actually decrease. The 
NSB asks if this is appropriate for all species, especially belugas. 
The NSB further notes that belugas have a mark for a footnote (**) but 
there is no corresponding discussion associated with the footnote.
    Response: As discussed in the previous response to comment, the 
adjustment factors under ``high adjustment'' were carried over from 
TGS' previous IHA application, and were not used in density estimates. 
Regarding the ``low adjustment'', there is only one adjustment factor 
(0.2) for gray whales, which is explained in the previous response to 
comment. Several species such as humpback, fin, minke, and killer 
whales, harbor porpoises, and ribbon and spotted seals, are not 
expected to occur north of 72[deg] N, therefore NMFS does not believe 
they would be taken north of 72[deg] N. For the rest of the marine 
mammal species, including beluga whales and bowhead whales, no 
adjustment was made in take calculation. As far as the extra footnote 
for beluga whale in Table 4 of TGS' IHA application, TGS responded that 
the corresponding notes to the footnote for beluga should read ``the 
beluga population estimate for the E Chukchi Sea is based on the 
minimum population estimate, as this is the only and most current up to 
date population estimate per the NMFS Stock Assessment Report.'' The 
note was accidentally omitted.
    Comment 11: The NSB notes that TGS should be congratulated for 
providing a range of estimates of numbers of marine mammals that may be 
exposed to seismic sounds. The NSB further states that this approach is 
an improvement over a single point estimate that is typically provided 
in an IHA application.
    Response: NMFS agrees with the NSB assessment that presenting a 
range of estimates of numbers of marine mammal that may be exposed to 
anthropogenic sounds is a better approach than a single number 
estimate.
    Comment 12: The NSB states that the approach for calculating the 
size of the ensonified area could lead to a negative bias in animals 
exposed to seismic sound because there are areas of overlap. The NSB 
notes that since most marine mammals will not stay stationary in one 
location of the Chukchi Sea over extended periods of time, the areas of 
overlap should be counted twice.
    Response: NMFS does not completely agree with the NSB's assessment. 
While there is a potential for negative bias in calculating animals 
exposed to seismic sound where the take zones overlap but the 
calculation is based on multiplying the ensonified area by marine 
mammal densities, such cases are only applicable to 3D seismic surveys 
and site clearance and shallow hazard surveys where the survey track 
lines are much closer together. For TGS' 2D seismic survey, the 
ensonified areas are established along each track line, which took into 
consideration areas where track lines crisscross and thus the 
overlapping areas are accounted for. Therefore, even though marine 
mammals may move in/out the survey area, the entire ensonified areas 
along the track lines were included in the calculation of exposures.
    Comment 13: The NSB and AWL claims that NMFS underestimated the 
number of animals that would be harassed from TGS's survey because it 
calculates harassment from TGS's proposed survey based on the exposure 
of marine mammals to impulsive sounds at or above 160 dB. The AWL 
states that this uniform approach to harassment does not take into 
account known reactions of marine mammals in the Arctic to levels of 
noise well below 160 dB. The NSB states that bowhead and beluga whales 
respond to anthropogenic sound at lower levels, as low as or lower than 
120 dB. Without citing specific research, the AWL claims that ``for 
harbor porpoises, behavioral changes, including exclusion from an area, 
can occur at received levels from 90-110 dB [near ambient level] or 
lower,'' and beluga whales ``are known to alter their migration paths 
in response to ice breaker noise at received levels as low as 80 dB 
[quiet ambient level].'' The AWL further pointed out that NMFS 
acknowledged the potential for behavioral disturbance to belugas at 
distances of 10-20 km, and for bowhead whales to react to sound levels 
lower than 160 dB.
    Response: NMFS does not agree with NSB and AWL's assessment on 
acoustic effects of marine mammals. Even though bowhead and beluga 
whales have been observed to respond to anthropogenic sound levels as 
low as 120 dB, as stated by the NSB, most likely those are non-impulse 
sounds (such as noise from icebreaking) as NSB did not provide specific 
description of characteristics of the noise. In general, marine mammals 
tend to respond to short pulses at higher received levels than longer 
non-pulse sound, hence the difference in NMFS current criteria of 
different take thresholds.
    In regards to the AWL's argument, first, the AWL did not provide a 
reference on harbor porpoise behavioral responses and exclusion from an 
area to received levels at 90-110 dB or lower, which is near the 
ambient noise level. Second, for the beluga whale example at quiet 
ambient level, although also not supported by a reference, such a 
deviation could be attributed to noise exposure to continuous sound 
(icebreaker), rather than exposure to seismic impulses. Additionally, 
as TGS does not intend to use icebreakers during its operations, 
statements regarding beluga reactions to icebreaker noise are not 
relevant to this activity. Concerning the behavioral disturbance by 
belugas at distances of 10-20 km, there was no mention of received 
level, so it is irrelevant to the AWL's argument concerning 160 dB 
received noise levels.
    Additionally, as stated in the past, NMFS does not believe that 
minor course corrections during a migration will always equate to 
``take'' under the MMPA. This conclusion is based on controlled 
exposure experiments conducted on migrating gray whales exposed to the 
U.S. Navy's low frequency sonar (LFA) sources (Tyack 2009). When the 
source was placed in the middle of the migratory corridor, the whales 
were observed deflecting around the source during their migration. 
However, such minor deflection is considered not to be biologically 
significant. To show the contextual nature of this minor behavioral 
modification, recent monitoring studies of Canadian seismic operations 
indicate that when not migrating, but involved in feeding, bowhead 
whales do not move away from a noise source at an SPL of 160 dB. 
Therefore, while bowheads may avoid an area of 20 km (12.4 mi) around a 
noise source, when that determination requires a post-survey computer 
analysis to find that bowheads have made a 1 or 2 degree course change, 
NMFS believes that does not rise to a level of a ``take.'' 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 
[mu]Pa). Although it is possible that marine mammals could react to any 
sound levels detectable above the ambient noise level within the 
animals' respective frequency response range, this does not mean that 
such animals would react in a biologically significant way. According 
to experts on marine mammal behavior, the degree of reaction which 
constitutes a ``take,'' i.e.,

[[Page 51152]]

a reaction deemed to be potentially biologically significant or that 
could potentially disrupt the migration, breathing, nursing, breeding, 
feeding, or sheltering, etc., of a marine mammal is complex and context 
specific, and it depends on several variables in addition to the 
received level of the sound by the animals. These additional variables 
include, but are not limited to, other source characteristics (such as 
frequency range, duty cycle, continuous vs. impulse vs. intermittent 
sounds, duration, moving vs. stationary sources, etc.); specific 
species, populations, and/or stocks; prior experience of the animals 
(naive vs. previously exposed); habituation or sensitization of the 
sound by the animals; and behavior context (whether the animal 
perceives the sound as predatory or simply annoyance), etc. (Southall 
et al. 2007).
    NMFS is in the process of developing revised acoustic criteria and 
thresholds for different sources, including seismic sources. The 
revised acoustic criteria will be peer-reviewed and made available for 
public comment. Until that process is complete, it is not appropriate 
to apply the new criteria and thresholds in any incidental take 
authorization. Instead, NMFS will continue its longstanding practice of 
considering specific modifications to the acoustic criteria and 
thresholds currently employed for incidental take authorizations only 
after providing the public with an opportunity for review and comment 
and responding to the comments.
    Comment 14: The AWL states that uncertainty precludes conclusions 
regarding take number and potential impacts. The AWL further states 
that NMFS must consider the extent of missing information about 
ecosystems in the Chukchi Sea, especially considering the large 
footprint of TGS' proposed survey.
    Response: Although NMFS agrees that it would be desirable to obtain 
additional information about the Chukchi Sea ecosystem and regional 
populations of marine mammals, NMFS has sufficient information to 
support its analysis of the potential impacts of TGS's proposed marine 
surveys on wildlife. As required by the MMPA implementing regulations 
at 50 CFR 216.102(a), NMFS has used the best scientific information 
available in assessing the level of take and whether the impacts would 
be negligible. The Federal Register notice for the proposed IHA, NMFS 
EA for the issuance of IHAs to take marine mammals incidental to open-
water marine and seismic surveys in 2013, and this document all provide 
detailed analysis using the best available scientific information that 
enables NMFS to make the required determinations. In addition, the 
required monitoring and mitigation measures prescribed in the IHA NMFS 
issued to TGS will further reduce any potential impacts of the proposed 
marine surveys on marine mammals.
    Comment 15: The AWL states that NMFS may not issue the IHA because 
it has not negated the possibility of serious injury from TGS's 
airguns. Further, the AWL noted that 18 years ago, NMFS once stated 
that permanent hearing loss qualifies as serious injury (60 FR 28381, 
May 31, 1995). A private citizen further states that the marine survey 
is ``massive deadly'' to marine mammals.
    Response: NMFS does not agree with the private citizen and AWL's 
assessment. NMFS was able to make a preliminary determination in the 
Federal Register for the proposed IHA to TGS to take marine mammals 
incidental to its open-water marine surveys. In addition, NMFS' 
preliminary determination states that the potential effects would be 
Level B behavioral harassment of small numbers of marine mammals in the 
project vicinity, and no injury, serious injury, or mortality is 
expected.
    Concerning the AWL's comments on NMFS 1995 proposed rule to 
implement the process to apply for and obtain an IHA, NMFS stated that 
authorizations for harassment involving the ``potential to injure'' 
would be limited to only those that may involve non-serious injury (60 
FR 28379; May 31, 1995). While the Federal Register notice cited by the 
commenters states that NMFS considered PTS to be a serious injury (60 
FR 28379; May 31, 1995), our understanding of anthropogenic sound and 
the way it impacts marine mammals has evolved since 1995, and NMFS no 
longer considers PTS to be a serious injury. NMFS has defined ``serious 
injury'' in 50 CFR 216.3 as ``. . . any injury that will likely result 
in mortality.'' There are no data that suggest that PTS would be likely 
to result in mortality, especially the limited degree of PTS that could 
hypothetically be incurred through exposure of marine mammals to 
seismic airguns at the level and for the duration that are likely to 
occur in this action.
    Further, as stated several times in this document and previous 
Federal Register notices for seismic activities, there is no empirical 
evidence that exposure to pulses of airgun sound can cause PTS in any 
marine mammal, even with large arrays of airguns (see Southall et al. 
2007). PTS is thought to occur several decibels above that inducing 
mild temporary threshold shift (TTS), the mildest form of hearing 
impairment (a non-injurious effect). NMFS concluded that cetaceans and 
pinnipeds should not be exposed to pulsed underwater noise at received 
levels exceeding, respectively, 180 and 190 dB re 1 [mu]Pa (rms). The 
established 180- and 190-dB re 1 [mu]Pa (rms) criteria are the received 
levels above which, in the view of a panel of bioacoustics specialists 
convened by NMFS before TTS measurements for marine mammals started to 
become available, one could not be certain that there would be no 
injurious effects, auditory or otherwise, to marine mammals. 
Additionally, NMFS has required monitoring and mitigation measures to 
negate the possibility of marine mammals being seriously injured or 
killed as a result of TGS's activities. In the proposed IHA, NMFS 
determined that TGS's activities are unlikely to even result in TTS. 
Based on this determination and the explanation provided here, PTS is 
also not expected. Therefore, an IHA is appropriate.
    Comment 16: The AWL claims that NMFS' take estimates of 30,000 
ringed seals, close to 1,500 gray whales, 800 bowhead whales, and 400 
beluga whales do not meet MMPA's ``small number'' requirement. The AWL 
further claims that NMFS underestimated the Level B takes in the 
proposed IHA.
    Response: NMFS does not agree with the AWL's assessment. First, as 
mentioned in the Federal Register notice for the proposed IHA and in 
this document, the estimated takes of the bowhead, gray, and beluga 
whales and ringed seals represent 7.53%, 7.13%, 11.11%, and 14.36% of 
their populations, respectively. As described in the Negligible Impact 
and Small Numbers Analysis and Determination section of this document, 
NMFS considers the number of authorized takes small. In addition, the 
percent population of bowhead whale takes is further reduced to 4.70% 
based on the most recent surveys and on the recommendation by 
scientists from the NSB (see Response to Comment 39).
    As discussed in detail in the Negligible Impact and Small Numbers 
Analysis and Determination section of this document, all takes from 
TGS' proposed open-water seismic surveys are expected to be Level B 
behavioral harassment, in the form of startle behavior or vacating the 
area for the short duration of time when the seismic airgun is firing 
in the area. Animals could also change their behavior patterns during 
this short duration, but are expected to resume their normal activities 
and reoccupy the area as soon

[[Page 51153]]

as the vessels move away. Additionally, since a portion of the proposed 
open-water seismic survey is planned in offshore waters far north above 
72[deg] N, it is expected to be outside the gray whale habitat. In 
addition, the mitigation and monitoring measures (described previously 
in the Federal Register notice for the proposed IHA) included in the 
IHA are expected to further reduce any potential disturbance to marine 
mammals.
    Comment 17: The AWL claims that NMFS' negligible impact finding is 
unjustified.
    Response: NMFS does not agree with the AWL's assessment. First, as 
discussed in the Negligible Impact and Small Numbers Analysis and 
Preliminary Determination section of the Federal Register notice for 
the proposed IHA, based on rigorous analyses, TGS' proposed 2D seismic 
surveys in the Chukchi Sea are expected to result in takes of small 
numbers of marine mammals in the form of Level B behavioral harassment. 
Animals exposed to airgun noises are expected to show brief startle 
reactions or to temporarily vacate the seismic site. No injury, serious 
injury, or mortality is expected, and none is authorized. Please also 
see Responses to Comments 15 and 16 for additional justification.
    Comment 18: The AWL states that NMFS must consider potential 
effects from masking and stress.
    Response: NMFS agree that potential acoustic masking and stress 
caused by anthropogenic sources could negatively affect marine mammal 
fitness and survival. The potential impacts from masking and stress by 
seismic surveys are considered and discussed in detail in the Federal 
Register notice for the proposed IHA. In this case, masking effects of 
pulsed sounds on marine mammal calls and other natural sounds are 
expected to be limited. Some whales continue calling in the presence of 
seismic pulses (e.g., Richardson et al. 1986; McDonald et al. 1995; 
Greene et al. 1999a, 1999b; Nieukirk et al. 2004; Smultea et al. 2004; 
Holst et al. 2005a, 2005b, 2006; Dunn and Hernandez 2009). In addition, 
marine mammals are thought to be able to compensate to some degree for 
masking by adjusting their acoustic behavior such as shifting call 
frequencies, and increasing call volume and vocalization rates, as 
discussed in the Federal Register notice for the proposed IHA (e.g., 
Miller et al. 2000; Parks et al. 2007; Di Iorio and Clark 2009; Parks 
et al. 2010).
    Although not much is known about potential stress to marine mammals 
from exposure from seismic surveys, the TGS' proposed 2D survey in the 
Chukchi Sea is short in duration, and will not stay in one area. 
Therefore, as analyzed in the Federal Register notice for the proposed 
IHA, the potential effects are expected to be negligible.

Mitigation

    Comment 19: AEWC requested that NMFS include the following 
provisions of the 2013 CAA in Section 6(d) of the IHA issued to TGS: 
Section 202(a) and (c): Com-Center General Communications Scheme; 
Section 204: Standardized Log Books; Section 302: Barge and Transit 
Vessel Operations; Section 402: Sound Signature Tests; Section 501: 
General provisions for Avoiding Interference with Bowhead Whales or 
Subsistence Whale Hunting Activities; Section 502(b): Limitations on 
Geophysical Activity in the Chukchi Sea; Section 505: Termination of 
Operations and Transit Through the Bering Strait; and Title VI, 
Sections 601 and 602: Late Season Seismic Operations.
    Response: NMFS has incorporated the above provisions of the 2013 
CAA into the IHA issued to TGS, as these measures will help ensure 
there is no unmitigable adverse impact on the availability of affected 
species or stock(s) for subsistence uses.
    Comment 20: The Commission requested that NMFS specify reduced 
vessel speeds of 9 knots or less when weather conditions or darkness 
reduce visibility.
    Response: NMFS worked with TGS and included the speed limitation 
requested by the Commission in the IHA as a mitigation measure for 
vessel movement.
    Comment 21: A private subsistence user comments that since seals 
diving to the bottom to feed on benthic organisms in deep water can 
stay down for an hour or more, NMFS should extend the visual monitoring 
of the exclusion zone to 30 minutes or longer before ramping up, after 
a shutdown due to a pinniped entering the zone.
    Response: NMFS is aware that pinnipeds are able to dive for long 
periods. However, in the case of TGS' 2D seismic survey, the required 
condition for ramping up seismic airguns after a shutdown triggered by 
pinniped presence is that (1) the pinniped is visually observed to have 
moved out of the exclusion zone, or (2) 15 minutes have passed since 
the last time the pinniped is seen. The time duration of 15 minutes is 
not based on the depth to which the pinniped can dive. Rather, it is 
based on the relatively small 190-dB exclusion zone for pinnipeds, and 
the speed of the seismic vessel, which is typically between 4 and 5 
knots. As presented in the Federal Register notice for the proposed 
IHA, the modeled 190-dB exclusion zones range from 430-930 m, depending 
on depth. Assuming that the radius of the zone is 930 m, and the source 
vessel is moving at a speed of 4 knots (7.4 km/hr), then in 15 minutes, 
the vessel will be at a location 1.85 km from where the pinniped was 
initially sighted. Therefore, NMFS believes that 15 minutes is a long 
enough duration to wait prior to safely ramping up seismic airguns 
after a shutdown caused by the presence of a pinniped.
    Comment 22: The AWL states NMFS should include provisions in the 
IHA that restrict TGS's operations based on geographic location, and/or 
time of year, such as restricting activity in certain areas, including 
subsistence use areas, areas of high productivity or diversity; areas 
that are important for feeding, migration, or other parts of the life 
history of species; or areas of biogenic habitat, structure-forming 
habitat, or habitat for endangered or threatened species.
    Response: While processing the proposed IHA, NMFS worked with TGS 
and conducted extensive analysis on the areas where TGS's proposed 
open-water marine surveys would occur. The areas TGS proposed to have 
its proposed marine surveys are analyzed in the proposed IHA process, 
during the section 7 consultation under the ESA, as well as under the 
NEPA analysis conducted during preparation of the EA. However, NMFS did 
not find that further restriction is needed given that no areas of high 
productivity or diversity, areas that are important for feeding and 
migration, or critical habitat for endangered or threatened species 
were found. Nevertheless, certain time and area restrictions are 
included in the IHA to minimize potential impacts on subsistence 
activities which are consistent with the CAA TGS has signed. These time 
and area restrictions are:
     Vessels should remain as far offshore as weather and ice 
conditions allow, and at least five miles offshore during transit,
     From August 31 to October 31 vessels in the Chukchi Sea or 
Beaufort Sea shall remain at least 20 miles offshore of the coast of 
Alaska from Icy Cape in the Chukchi Sea to Pitt Point on the east side 
of Smith Bay in the Beaufort Sea whether in transit or engaging in 
activities in support of oil and gas operations unless ice conditions 
or an emergency that threatens the safety of the vessel or crew 
prevents compliance with this requirement,

[[Page 51154]]

     Beginning September 15, and ending with the close of the 
fall bowhead whale hunt, if Wainwright, Pt. Lay, or Pt. Hope intend to 
whale in the Chukchi Sea, no more than two geophysical activities 
employing geophysical equipment will occur at any one time in the 
Chukchi Sea. During the fall bowhead whale hunt, geophysical equipment 
will not be used within 30 miles of any point along the Chukchi Sea 
coastline. Industry participants will contact the Whaling Captains' 
Associations of each village to determine if a village is prepared to 
whale and will notify the AEWC of any response, and
     All Industry participant vessels shall complete operations 
in time to allow such vessels to complete transit through the Bering 
Strait to a point south of 59 degrees North latitude no later than 
November 15, 2013.
    Comment 23: The AWL states that NMFS should examine imposing 
requirements for the use of new technology that could reduce the 
footprint of seismic exploration. The AWL cited an expert conference in 
February in Silver Spring, Maryland, by NMFS on alternative 
technologies for offshore energy production and requested that NMFS 
consider (1) Mandating the use of marine vibroseis or other 
technologies in some or all of the survey area; (2) mandating the 
testing of marine vibroseis in a pilot area, precedent to a decision to 
permit seismic activity, with an obligation to accrue data on 
environmental impacts; (3) deferring the permitting of surveys in part 
or all of the survey area until effective mitigative technologies, such 
as marine vibroseis, become available; (4) providing incentives for 
TGS's use of these technologies as was done for passive acoustic 
monitoring systems; and (5) exacting funds from TGS to support 
accelerated mitigation research in this area.
    Response: First, the February workshop (not an ``expert 
conference'') in Silver Spring, Maryland, titled Quieting Technologies 
for Reducing Noise during Seismic Surveying and Pile Driving, was 
convened by BOEM, not NMFS. The goals of the workshop, as stated in the 
Web site of the workshop, were to (1) Review and examine recent 
developments (existing, emerging, and potential) in quieting 
technologies for seismic surveying, whether proposed or in development; 
(2) identify the requirements for operation and limitations for using 
these technologies; (3) evaluate data quality and cost-effectiveness of 
these technologies as compared to that from existing marine acoustic 
technologies; (4) identify the acoustic characteristics of new 
technologies in varying environments compared to that from existing 
technologies; (5) examine potential environmental impacts from these 
technologies; (6) identify which technologies, if any, provide the most 
promise for full or partial traditional use and specify the conditions 
that might warrant their use (e.g., specific limitations to water 
depth, use in Marine Protected Areas, etc.); and (7) identify next 
steps, if appropriate, for the further development of these 
technologies, including potential incentives for field testing. Most of 
these technologies are still in research and development stages and 
have not been field tested. The workshop provided a forum for 
discussion and evaluation of such technologies, including vibroseis. 
NMFS supports and encourages both the development and use of 
technologies that will reduce impacts to marine mammals and other 
marine species. These alternative technologies will likely be adopted 
for use to replace some subset of future seismic survey activities once 
their development is further along and their environmental impacts, 
especially as compared to seismic airguns, are better understood. 
However, NMFS does not believe it can currently mandate the use of such 
technologies.

Monitoring

    Comment 24: The Commission requests NMFS only authorize an in-
season adjustment in the size of the exclusion and/or disturbance zones 
if the size(s) of the estimated zones are determined to be too small. 
The Commission states that the purpose of SSV is to ensure protection 
of marine mammals, and one way to reduce risk to marine mammals would 
be to only allow expansion of the exclusion and/or disturbance zones.
    Response: NMFS does not agree with the Commission's recommendation. 
While it may seem to be more protective to increase the size of the 
exclusion zone, if the effectiveness of visual-based marine mammal 
monitoring remains the same, the actual result may not be an increase 
in protection. For example, when the SSV suggests that the exclusion 
and/or disturbance zones are smaller than the ones modeled and 
monitoring still focuses on the larger modeled zones, it is likely that 
the effectiveness of marine mammal monitoring could be reduced as the 
area to be monitored would be larger than necessary. In addition, 
larger than realistic exclusion zones would cause unnecessary power-
down and shutdowns, which could increase the total duration of the 
marine surveys, and cause unnecessary impacts to the marine 
environment.
    Comment 25: The Commission requests NMFS require TGS to monitor for 
marine mammals 30 minutes before, during, and 30 minutes after survey 
operations and other activities have ceased.
    Response: TGS is required to monitor for marine mammals 30 minutes 
before, during, and 30 minutes after survey operations and other 
activities have ceased.
    Comment 26: The Commission requests NMFS encourage TGS to deploy 
additional protected species observers to (1) increase the probability 
of detecting all marine mammals in or approaching the Level A and B 
harassment zones and (2) assist in the collection of data on 
activities, behaviors, and movements of marine mammals around the 
source.
    Response: NMFS agrees that an adequate number of PSOs is critical 
to ensure complete coverage in visual monitoring and implementing 
mitigation measures. While it is reasonable to conclude that additional 
PSOs would increase detection capability to a certain degree, the 
number of PSOs that can be stationed on vessels is limited by the 
available berth spaces. TGS plans to have 5 PSOs onboard the survey 
vessel and 4 onboard the scout vessel, and will have 100% monitoring 
coverage during all periods of survey operations in daylight. In 
addition, each PSO is limited to maximum of 4 consecutive hours per 
watch and maximum of 12 hours of watch time per day. NMFS believes that 
the number of PSOs onboard is adequate given the limited space 
available on the survey vessel.
    Comment 27: The NSB notes that towed PAM will be used for marine 
mammal monitoring during TGS' 2D seismic survey. The NSB states that 
PAM is still in the research and development phase, and that it is not 
clear whether it will provide useful data. In addition, the NSB states 
that since the PAM will be towed by the scout vessel thus presumably 
reducing the maneuverability of the scout vessel. The NSB further 
states that the scout vessel would have a more difficult time visually 
monitoring the safety and behavioral impact zones with the streaming 
towed array.
    Response: NMFS is aware of the technical challenges involved in 
towed PAM for marine mammal monitoring. Nevertheless, given the needs 
for marine mammal monitoring at far-field beyond visual observation, 
and the technological progresses made in the

[[Page 51155]]

past few years regarding towed PAM, it is worth the efforts to require 
towed PAM as an extra modality to monitor marine mammal presence in the 
seismic survey area, and to enhance visual monitoring. Towed PAM has 
been used in past IHAs issued by NMFS for marine mammal monitoring in 
the Arctic (e.g., open-water seismic survey by StatOil in the Chukchi 
Sea in 2010), and the results indicated more acoustic detections than 
visual detections, and acoustic detections have led to visual 
detections of marine mammals. Regarding towed PAM for TGS' 2D seismic 
survey, NMFS worked with the applicant and its acoustic contractor and 
carefully reviewed all technical aspects of the acoustic monitoring 
design and methods. The reason that PAM will be conducted from the 
scout vessel is to decouple the PAM array from the seismic streamer and 
airgun arrays. In addition, because the purpose of the towed PAM is to 
expand the monitoring to the far-field by positioning them 
approximately 2 km ahead of the seismic vessel, it makes sense that the 
PAM array be deployed off the scout vessel. The design will not reduce 
the maneuverability of the scout vessel since the scout vessel is 
positioned to be approximately 2 km ahead of the seismic vessel for 
far-field monitoring. More details of the towed PAM design and 
discussion are described in TGS' 4MP.
    Comment 28: The NSB states that because the towed PAM is not a 
proven technique for monitoring marine mammals in the vicinity of a 
seismic survey in the Arctic, NMFS should require TGS to collect 
acoustic data using bottom mounted instruments. The NSB states that TGS 
should deploy at least several instruments in the northern areas of 
their proposed seismic survey area.
    Response: As discussed above, NMFS is aware of the technical 
challenges involved in implementing towed PAM for marine mammal 
monitoring. The justification and improvement in implementing the towed 
PAM as an effective tool for marine mammal monitoring is discussed in 
Response to Comment 27. As discussed in the Federal Register notice for 
the proposed IHA, NMFS discussed extensively with TGS ways to improve 
the far-field marine mammal monitoring. As a result, upon further 
investigation and conversations with both JASCO and Bio-Waves by TGS, 
as well as further research into past Arctic marine mammal monitoring 
results conducted with towed-PAM, NMFS and TGS agree that utilizing a 
well-designed towed-PAM system would be a better choice under this 
circumstance to provide enhanced marine mammal monitoring beyond 
exclusion zones in a real time basis, as well as using acoustic data 
for limited relative abundance and distribution analysis, and possibly 
limited insights on impacts to marine mammals.
    NMFS also studied other PAM methodologies suggested by the peer-
review panel. First, concerning deploying fixed bottom mounted 
instruments, TGS states that it worked with other operators but was not 
able to find a collaborator to participate in long-term acoustic 
monitoring due to the short-term nature of the proposed survey. 
Regarding real-time acoustic monitoring with a fixed buoy, TGS stated 
that it conducted an evaluation of this option and discussed the 
possibility with Cornell University's Bioacoustical Research Program 
concerning its real-time marine acoustic recording unit (MARU), but 
decided that the technology is still in the research and development 
stage. When the fact that the equipment is still in the developmental 
stages is considered in combination with the increased cost of this 
technology, TGS believes that the downsides of using fixed buoys 
outweigh the potential benefits and that towed PAM is a more effective 
solution. Therefore, NMFS considers in this case that a towed PAM is a 
reasonable alternative for passive acoustic monitoring.
    Comment 29: The AWL claims that NMFS' proposed mitigation measures 
are ineffective and do not negate the potential for serious injury. 
Citing the example of ION Geophysical's 90-day monitoring report, the 
AWL points out the difficulty of monitoring these zones at distances 
greater than 2.2 miles. The AWL further states that since the very 
large size of the 180-dB exclusion zone could extend to 2.5 km (1.5 mi) 
from the sound source, depending on water depth, marine mammals could 
be injured. The AWL also points out that the proposed monitoring 
measures for behavioral harassment were also inadequate as the 160 dB 
zone could extend to 15 km from the source. Further, the AWL states 
that the Open-water peer review panel reviewing TGS's proposed 
activities also noted serious limitations of visual monitoring, and 
that ``PSOs on the scout vessel will only be able to monitor a small 
portion of the 160 dB zone.'' Finally, the AWL quotes ION's 90-day 
report as saying ``nights with fog, no ambient light, or heavy seas 
made observations nearly impossible.''
    Response: NMFS recognizes the limitations of visual monitoring as 
distance increases. However, TGS's proposed open-water seismic survey 
would employ a scout vessel to supplement the visual monitoring of the 
exclusion zone at a distance of approximately 2 km in front of the 
source vessel, to ensure that the exclusion zone is free of marine 
mammals during the survey. In addition, NMFS recognizes that 2.5 km 
(1.5 mi) is a large distance for vessel monitoring, however, based on 
prior marine mammal monitoring reports, this distance is well within 
the line of sight and can be effectively monitored by experienced PSOs. 
Furthermore, towed PAM will be implemented to supplement marine mammal 
monitoring to further increase the chance of detecting marine mammals 
in the survey vicinity.
    Concerning far field monitoring of the 160-dB zone, NMFS recognizes 
the limitations of visual monitoring, but again, towed PAM will provide 
information on marine mammals in the vicinity. It is likely that towed 
PAM designed for TGS' seismic survey will be able to localize marine 
mammals in the far field beyond exclusion zones, as discussed in detail 
in the Federal Register notice for the proposed IHA.
    In addition, NMFS also recognizes the limitations of visual 
monitoring in darkness and other inclement weather conditions. 
Therefore, in the IHA issued to TGS, NMFS required that no seismic 
airgun can be ramped up when the entire exclusion zones are not 
visible. However, TGS's operations will occur in an area where periods 
of darkness do not begin until early September. Beginning in early 
September, there will be approximately 1-3 hours of darkness each day, 
with periods of darkness increasing by about 30 min each day. By the 
end of the survey period, there will be approximately 8 hours of 
darkness each day. These conditions provide PSOs favorable monitoring 
conditions for most of the time.
    Comment 30: The AWL states that the use of PAM does not remedy 
AWL's perceived flaws in the mitigation regime, and the AWL is not 
clear whether or how towed PAM will be used to improve implementation 
of the exclusion zones. The AWL further states NMFS provided less 
detail about how the PAM system will work by stating that details and 
specifications of the equipment will be determined at a later date once 
TGS has identified a contractor for the system.
    Response: Concerning the effectiveness of using towed PAM to 
supplement marine mammal monitoring, and the effectiveness of 
implementing towed PAM, please refer

[[Page 51156]]

to Response to Comment 27. The utilization of towed PAM to improve 
implementation of the exclusion zones is discussed in detail in the 
Federal Register notice for the proposed IHA and in TGS' 4MP. In 
summary, using towed PAM to supplement marine mammal visual detection 
has been required by NMFS in the past for various marine seismic and 
geophysical activities and it has proven to be effective. Specifically, 
there are far more acoustic detections than visual detection of marine 
mammals, and many visual detections were based on initial acoustic 
detection of marine mammals in the project vicinity. In addition, for 
the TGS' seismic survey, marine mammal localization by towed PAM is 
also proposed by using target motion analysis. With this method, it is 
possible with a single towed hydrophone array to obtain a localization 
to vocalizing animals given certain assumptions. Although due to the 
linear alignment of hydrophones, there is a left/right ambiguity that 
cannot be resolved without turning the tow vessel, this ambiguity is 
not a concern for mitigation during the seismic survey because the 
exclusion zones are circular and would encompass both sides of the 
hydrophones. Therefore, the distance to the calling animal is the same 
on the right and left side of the vessel.
    Although at the time when the Federal Register notice for the 
proposed IHA was published NMFS did not have specific information 
concerning the design of the towed PAM, specific requirements for an 
effective towed PAM were analyzed and requested. For example, the towed 
PAM system shall be able to monitor marine mammal occurrence within 160 
dB isopleths, and shall minimize the interferences from flow noise by 
equipping the system with pre-amplifier filters that are ``tuned'' to 
reduce low-frequency flow and vessel noise. Detailed discussion on 
these requirements and specifications are provided in the Federal 
Register notice for the proposed IHA and in TGS' 4MP.
    Comment 31: Citing ION's error in its initial exclusion zone 
measurements, the AWL states that sound measurements used to estimate 
the size of safety radii from which animals should be excluded can 
easily be miscalculated. The AWL further requests NMFS require sound 
source verification before any activities commence to ensure no similar 
errors and resulting takes occur during TGS' proposed activities.
    Response: Although NMFS recognizes the error made by ION's 
contractor during the sound source verification measurement and the 
radius of the 180-dB exclusion was originally estimated less than it 
was measured to be, NMFS does not agree with AWL's speculation that 
sound measurements used to estimate the size of exclusion zones can be 
``easily miscalculated.'' The ION incident was not due to 
miscalculation. It was due to human error in data handling and is 
preventable. NMFS has subsequently discussed this with ION and its 
contractor to make sure that rigorous checks and verification are 
performed to ensure no error in data handling.
    NMFS agrees with the AWL that SSV will be conducted before TGS 
commences its seismic surveys in the Chukchi Sea.

Subsistence Issues

    Comment 32: The NSB requests NMFS require TGS to sign the CAA with 
the Alaska Eskimo Whaling Commission (AEWC).
    Response: The signing of a CAA is not a requirement to obtain an 
IHA. The CAA is a document that is negotiated between and signed by the 
industry participant, AEWC, and the Village Whaling Captains' 
Associations. Although the contents of a CAA may inform NMFS' ``no 
unmitigable adverse impact'' determination for bowhead and beluga 
whales, the signing of it is not a requirement. Nevertheless, TGS 
signed the 2013 CAA and NMFS incorporated all relevant measures that 
will help to ensure no unmitigable adverse impacts to subsistence 
harvest activities into the IHA issued to TGS.
    Comment 33: The Commission recommends that NMFS encourage the 
development of conflict avoidance agreements that reflect the interests 
of all potentially affected communities and co-management organizations 
and account for potential adverse impacts on all marine mammal species 
taken for subsistence.
    Response: TGS signed a Conflict Avoidance Agreement (CAA) with the 
Alaska native whaling communities to ensure that there is no 
unmitigable adverse impacts to subsistence whaling activities from its 
proposed 2D seismic survey in the Chukchi Sea. For marine mammal 
species other than bowhead whales, TGS developed a POC and engaged with 
all potentially affected communities and co-management organizations to 
ensure that the potential effects to subsistence activities can be 
mitigated. In addition, TGS developed a marine mammal monitoring and 
mitigation plan to make sure that there will be no unmitigable impacts 
to subsistence use of all marine mammal species by the native 
communities. Finally, NMFS has rigorously reviewed TGS' POC and the 4MP 
and provided additional recommendations (e.g., passive acoustic 
monitoring) to further reduce any adverse effects. NMFS has 
subsequently made a determination that TGS' 2013 open-water 2D seismic 
survey will not have unmitigable adverse impacts to subsistence use of 
any marine mammal species. Neither the MMPA nor its implementing 
regulations require an independent legal agreement between TGS and any 
subsistence use representative. TGS has already ensured there will be 
no unmitigable adverse impact to subsistence uses.
    Comment 34: The AEWC and NSB point out that currently there are 11 
villages that take bowhead whales, not 10 as described in the Federal 
Register notice for the proposed IHA. The AEWC further asks NMFS to 
update the discussion of Barrow whaling to acknowledge the increasing 
importance of the fall hunt.
    Response: NMFS appreciates the additional new information on the 
current subsistence whaling activities and clarifying the role of the 
fall bowhead whale hunt. NMFS' analyses provided in the Federal 
Register notice for the proposed IHA was based on historical data as 
the most recent data from the same season may not be available at the 
time of analysis. NMFS has incorporated this information into the 
subsistence impact analysis in this document.
    Comment 35: Citing the Federal Register notice for the proposed IHA 
that NMFS states that the provisions in the POC ``should minimize 
impacts to subsistence hunters,'' the AEWC argues that ``should'' and 
``minimize'' simply has no place in the statutory analysis. The AEWC 
states that NMFS must determine that the proposed activities ``will not 
have an unmitigable adverse impact on the availability of such species 
or stock for taking for subsistence uses.''
    Response: NMFS agrees with the AEWC's point and considers that the 
sentence in the ``Unmitigable Adverse Impact Analysis and Preliminary 
Determination'' section of the Federal Register notice did not 
accurately convey NMFS analyses on subsistence affects. NMFS 
subsequently corrected the sentence to read ``TGS has adopted a spatial 
and temporal strategy for its Chukchi Sea open-water seismic surveys 
that will have no unmitigable impacts to subsistence hunters'' under 
the ``Unmitigable Adverse Impact Analysis and Determination'' section 
of this document.

[[Page 51157]]

NEPA Concern

    Comment 36: The AEWC and AWL state that NMFS must address the 
potential cumulative effects of multiple concurrent seismic operations 
in the Chukchi and Beaufort Seas.
    Response: NMFS prepared an EA to analyze and address cumulative 
impacts of other oil and gas activities planned for the Arctic Ocean. 
The oil and gas related activities in the U.S. Arctic in 2013 include 
this activity and Shell's open-water marine surveys in the Chukchi Sea. 
Seismic survey activities in the Canadian and Russian Arctic occur in 
different geophysical areas, therefore, they are not analyzed under the 
NMFS 2013 EA. Other appropriate factors, such as Arctic warming, 
military activities, and noise contributions from community and 
commercial activities were also considered in NMFS' 2013 EA. Please 
refer to that document for further discussion of cumulative impacts.
    Comment 37: The AWL notes that NMFS is in the middle of preparing a 
programmatic EIS for Arctic Ocean oil and gas exploration, and states 
that NEPA prohibits piecemeal approvals while a programmatic EIS 
process is ongoing, except under strictly prescribed circumstances not 
found here. The AWL further states that if NMFS were to allow TGS' 
activities to go forward pending completion of the EIS, NMFS risks 
undermining the overarching aim of the programmatic EIS process to 
establish appropriate standards for future oil and gas activities that 
address and mitigate potential cumulative effects of the activities.
    Response: NMFS does not agree with the AWL statement. While the 
analysis contained in the Final EIS will apply more broadly to Arctic 
oil and gas operations, NMFS' issuance of an IHA to TGS for the taking 
of several species of marine mammals incidental to conducting its open-
water marine survey in the Chukchi Sea in 2013, as analyzed in the EA, 
is not expected to significantly affect the quality of the human 
environment. In the 2013 Arctic EA, NMFS included a rigorous analysis 
on cumulative effects of all activities currently occurring in the 
Arctic. TGS's surveys are not expected to significantly affect the 
quality of the human environment because of the limited duration and 
scope of operations.

ESA Concern

    Comment 38: The AWL states that although NMFS has completed a 
programmatic biological opinion for Arctic oil and gas activities, it 
must also thoroughly analyze the impacts of the specific activities 
authorized here including future impacts. The AWL further states that 
in order to comply with the ESA, this site-specific analysis must 
include an incidental take statement specifying the number and type of 
takes expected.
    Response: For the issuance of the IHA to TGS, NMFS' Permits and 
Conservation Division initiated consultation with NMFS Alaska Regional 
Office (AKRO) Protected Resources Division under section 7 of the ESA 
on the issuance of an IHA to TGS under section 101(a)(5)(D) of the MMPA 
for this activity. The consultation took into consideration the 
specific activities proposed to be authorized and all aspects of 
current and future impacts to the species. A Biological Opinion was 
issued on June 19, 2013, which concludes that issuance of the IHA is 
not likely to jeopardize the continued existence of the ESA-listed 
marine mammal species. In addition, analysis by NMFS AKRO showed that 
humpback whale will not be affected, therefore, no take was authorized. 
NMFS will issue an Incidental Take Statement under this Biological 
Opinion which contains reasonable and prudent measures with 
implementing terms and conditions to minimize the effects of take of 
listed species.

Miscellaneous

    Comment 39: The NSB points out that the most recent bowhead 
population estimates are: 12,631 from 2004 (Koski et al. 2010) and 
16,892 for 2011 (Givens et al. 2013).
    Response: NMFS appreciates NSB pointing out the most recent bowhead 
population estimates and made corrections in the relevant section. With 
the revised population estimates, the percentage of the Bering-Chukchi-
Beaufort Sea population of bowhead whales that could be taken by Level 
B harassment is changed from 7.53% to 4.70%.
    Comment 40: The NSB notes that TGS has proposed to coordinate with 
state, federal and NSB divisions but has not discussed how they will 
coordinate with other industry operators. The NSB points out that 
Shell, ConocoPhillips and Statoil have an extensive monitoring program 
in the Chukchi Sea, including passive acoustic monitoring (PAM). The 
NSB points out that results from that PAM could provide useful 
information about possible impacts from TGS' seismic operations. The 
NSB requests NMFS require TGS to work with other industry partners who 
are collecting useful data in the area where they are operating.
    Response: As discussed in the Federal Register notice for the 
proposed IHA, NMFS has discussed extensively with TGS on a variety of 
techniques to improve its far field monitoring, including PAM using 
ocean bottom mounted acoustic sensors. During the course of discussion, 
TGS stated that it was in contact with other industry operators but was 
not able to find a collaborator to participate in long-term acoustic 
monitoring due to the short-term nature of its proposed survey. 
Further, NMFS cannot legally require TGS to work with other industry 
partners under the MMPA. Nevertheless, TGS is able to implement PAM 
with towed acoustic arrays, as described in detail in the Federal 
Register notice for the proposed IHA and in this document.
    Comment 41: The Commission requested that NMFS allow sufficient 
time between the close of the comment period and the issuance of an IHA 
for NMFS to analyze, consider, and respond fully to comments received 
and incorporate recommended changes, as appropriate--the applicable 
statutory provision, section 101(a)(5)(D)(iii), anticipates that up to 
45 days might be required. The Commission points out that the deadline 
for comments on the proposed IHA is July 12, 2013, yet the IHA was 
proposed to be issued on July 15, 2013. The Commission states that it 
is concerned that the time between the close of the comment period and 
the issuance of the IHA does not provide adequate opportunity for NMFS 
to consider, provide adequate responses to, and incorporate any changes 
prompted by comments from the Commission and the public.
    Response: NMFS always fully reviews and considers comments 
submitted by the Commission and the public, and works with the 
applicant to incorporate such input as appropriate. In the case of the 
TGS IHA, NMFS is actively working with the applicant on the scheduling 
issue, and since the publication of the Federal Register notice for the 
proposed IHA, TGS has indicated that its 2D seismic survey would 
probably start in early August, thus giving NMFS extra time to complete 
the process.

Description of Marine Mammals in the Area of the Specified Activity

    The marine mammal species under NMFS jurisdiction most likely to 
occur in the seismic survey area include eight cetacean species: beluga 
whale (Delphinapterus leucas), harbor porpoise (Phocoena phocoena), 
killer whale (Orcinus orca), bowhead whale (Balaena mysticetus), gray 
whale (Eschrichtius robustus), minke whale

[[Page 51158]]

(Balaenoptera acutorostrata), fin whale (B. physalus), and humpback 
whale (Megaptera novaeangliae), and four pinniped species, ringed 
(Phoca hispida), spotted (P. largha), bearded (Erignathus barbatus), 
and ribbon seals (Histriophoca fasciata).
    The bowhead, fin, and humpback whales are listed as ``endangered'', 
and the ringed and bearded seals are listed as ``threatened'' under the 
Endangered Species Act (ESA) and as depleted under the MMPA. Certain 
stocks or populations of gray and beluga whales and spotted seals are 
also listed under the ESA, however, none of those stocks or populations 
occur in the proposed activity area.
    TGS' application contains information on the status, distribution, 
seasonal distribution, and abundance of each of the species under NMFS 
jurisdiction mentioned in this document. Please refer to the 
application for that information (see ADDRESSES). Additional 
information can also be found in the NMFS Stock Assessment Reports 
(SAR). The Alaska 2012 SAR is available at: http://www.nmfs.noaa.gov/pr/sars/pdf/ak2012.pdf.

Potential Effects of the Specified Activity on Marine Mammals

    Operating active acoustic sources such as airgun arrays, 
navigational sonars, and vessel activities have the potential for 
adverse effects on marine mammals. Potential effects from TGS' 2D 
seismic survey on marine mammals in the Chukchi Sea are discussed in 
the Federal Register (78 FR 35508; June 12, 2013) notice for the 
proposed IHA. No changes have been made to the discussion contained in 
this section of the Federal Register notice for the proposed IHA.

Anticipated Effects on Habitat

    The primary potential impacts to marine mammal habitat are 
associated with elevated sound levels produced by airguns and vessels 
and their affects to marine mammal prey species. These potential 
effects from TGS' 2D seismic survey are discussed in the Federal 
Register (78 FR 35508; June 12, 2013) notice for the proposed IHA. No 
changes have been made to the discussion contained in this section of 
the Federal Register notice for the proposed IHA.

Potential Impacts on Availability of Affected Species or Stock for 
Taking for Subsistence Uses

    Subsistence hunting is an essential aspect of Inupiat Native life, 
especially in rural coastal villages. The Inupiat participate in 
subsistence hunting activities in and around the Chukchi Sea. The 
animals taken for subsistence provide a significant portion of the food 
that will last the community through the year. Marine mammals represent 
on the order of 60-80% of the total subsistence harvest. Along with the 
nourishment necessary for survival, the subsistence activities 
strengthen bonds within the culture, provide a means for educating the 
young, provide supplies for artistic expression, and allow for 
important celebratory events.

Potential Impacts to Subsistence Uses

    NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103 
as: ``. . . an impact resulting from the specified activity: (1) That 
is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.''
(1) Bowhead Whales
    TGS' planned seismic surveys would have no or negligible effects on 
bowhead whale harvest activities. Noise and general activity associated 
with seismic surveys and operation of vessels has the potential to 
harass bowhead whales. However, though temporary diversions of the swim 
path of migrating whales have been documented, the whales have 
generally been observed to continue their migration via a deflected 
migratory route. The proposed open-water seismic surveys and vessel 
noise could affect subsistence hunts by placing the animals further 
offshore or otherwise at a greater distance from villages thereby 
increasing the difficulty of the hunt or retrieval of the harvest, or 
creating a safety risk to the whalers. Further, whales have the 
potential to become skittish--changing their swim speeds, breathing 
rates, and other migratory behavior--when exposed to seismic and vessel 
noise, even if they do not deflect, thus make hunting more difficult.
    Eleven primary coastal Alaskan villages deploy whaling crews during 
whale migrations. Around the TGS' proposed project area in the Chukchi 
Sea, the primary bowhead hunting villages that could be affected are 
Barrow, Wainwright, and Point Hope. Whaling crews in Barrow hunt in 
both the spring and the fall (Funk and Galginaitis 2005). The primary 
bowhead whale hunt in Barrow occurs during spring, while the fall hunt 
is used to meet the quota and seek strikes that can be transferred from 
other communities. In the spring, the whales are hunted along leads 
that occur when the pack ice starts deteriorating. This tends to occur 
between the first week of April through May in Barrow and the first 
week of June in Wainwright, well before the proposed 2D seismic surveys 
would be conducted. The Point Hope bowhead whale hunt occurs from March 
to June. Whaling camps are established on the ice edge south and 
southeast of Point Hope, 10 to 11 km (6 to 7 mi) offshore. However, due 
to extremely dangerous and challenging ice conditions, along with 
persistent strong westerly and southwesterly winds in 2013, the spring 
bowhead whale subsistence hunt fell far below the subsistence needs 
this year. Only four of the villages were able to take any whales: 
Gambell landed two out of a quota of eight, Savoonga landed four out of 
a quota of eight, and Pt. Hope landed five out of a quota of 10. Barrow 
was able to land only one whale out of a quota of 22. The remaining 
spring villages were unable to take any whales. As a result, the fall 
hunting will be especially important, not only for Barrow and the 
Beaufort Sea villages, but also for attempts out of Wainwright, Pt. 
Lay, and possibly Pt. Hope. Nevertheless, the proposed seismic survey 
would be conducted in the West of Point Barrow in the Chukchi Sea far 
offshore.
(2) Beluga Whales
    Belugas typically do not represent a large proportion of the 
subsistence harvests by weight in the communities of Wainwright and 
Barrow. Barrow residents hunt beluga in the spring (normally after the 
bowhead hunt) in leads between Point Barrow and Skull Cliffs in the 
Chukchi Sea primarily in April-June, and later in the summer (July-
August) on both sides of the barrier island in Elson Lagoon/Beaufort 
Sea (MMS 2008), but harvest rates indicate the hunts are not frequent. 
Wainwright residents hunt beluga in April-June in the spring lead 
system, but this hunt typically occurs only if there are no bowheads in 
the area. Communal hunts for beluga are conducted along the coastal 
lagoon system later in July-August. Between 2005 and 2009, the annual 
beluga subsistence take was 94 whales (Allen and Angliss 2012) among 
both Wainwright and Barrow.
    Belugas typically represent a much greater proportion of the 
subsistence harvest in Point Lay and Point Hope. Point Lay's primary 
beluga hunt occurs from mid-June through mid-July, but can sometimes 
continue into August if

[[Page 51159]]

early success is not sufficient. Belugas are harvested in coastal 
waters near these villages, generally within a few miles from shore. 
However, the southern extent of TGS' proposed surveys is over 88 m to 
the north of Point Lay, and much farther away from Point Hope. 
Therefore NMFS considers that the surveys would have no or negligible 
effect on beluga hunts.
(3) Seals
    Seals are an important subsistence resource and ringed seals make 
up the bulk of the seal harvest. Most ringed and bearded seals are 
harvested in the winter or in the spring before TGS' 2013 activities 
would commence, but some harvest continues during open water and could 
possibly be affected by TGS' planned activities. Spotted seals are also 
harvested during the summer. Most seals are harvested in coastal 
waters, with available maps of recent and past subsistence use areas 
indicating seal harvests have occurred only within 30-40 mi (48-64 km) 
off the coastline. TGS does not plan to survey within 88 km (55 mi) of 
the coast, which means that the proposed activities are not likely to 
have an impact on subsistence hunting for seals.
    As stated earlier, the proposed seismic survey would take place 
between July and October. The proposed seismic survey activities would 
be conducted in far offshore waters of the Chukchi Sea and away from 
any subsistent activities. In addition, the timing of the survey 
activities that would be conducted between July and October would 
further avoid any spring hunting activities in Chukchi Sea villages. 
Therefore, due to the time and spatial separation of TGS' proposed 2D 
seismic surveys and the subsistence harvest by the local communities, 
it is anticipated to have no effects on spring harvesting and little or 
no effects on the occasional summer harvest of beluga whale, 
subsistence seal hunts (ringed and spotted seals are primarily 
harvested in winter while bearded seals are hunted during July--
September in the Beaufort Sea), or the fall bowhead hunt.
    In addition, TGS has developed and proposes to implement a number 
of mitigation measures (described in the next section) which include a 
Marine Mammal Monitoring and Mitigation Plan (4MP), employment of 
subsistence advisors in the villages, and implementation of a 
Communications Plan (with operation of Communication Centers). TGS has 
also prepared a Plan of Cooperation (POC) under 50 CFR 216.104 that 
addresses potential impacts on subsistence seal hunting activities.
    Finally, to ensure that there will be no conflict from TGS' 
proposed open-water seismic surveys to subsistence activities, TGS 
stated that it will maintain communications with subsistence 
communities via the communication centers (Com and Call Centers) and 
signed the Conflict Avoidance Agreement (CAA) with Alaska whaling 
communities.

Mitigation Measures

    In order to issue an incidental take authorization under Section 
101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods 
of taking pursuant to such activity, and other means of effecting the 
least practicable adverse impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and on the availability of such species 
or stock for taking for certain subsistence uses.
    For the proposed TGS open-water marine 2D seismic surveys in the 
Chukchi Sea, NMFS is requiring TGS to implement the following 
mitigation measures to minimize the potential impacts to marine mammals 
in the project vicinity as a result of its survey activities. The 
primary purpose of these mitigation measures is to detect marine 
mammals within, or about to enter designated exclusion zones and to 
initiate immediate shutdown or power down of the airgun(s).

(1) Establishing Exclusion and Disturbance Zones

    Under current NMFS guidelines, the ``exclusion zone'' for marine 
mammal exposure to impulse sources is customarily defined as the area 
within which received sound levels are >=180 dB (rms) re 1 [mu]Pa for 
cetaceans and >=190 dB (rms) re 1 [mu]Pa for pinnipeds. These safety 
criteria are based on an assumption that SPL received at levels lower 
than these will not injure these animals or impair their hearing 
abilities, but that at higher levels might have some such effects. 
Disturbance or behavioral effects to marine mammals from underwater 
sound may occur after exposure to sound at distances greater than the 
exclusion zones (Richardson et al. 1995). Currently, NMFS uses 160 dB 
(rms) re 1 [mu]Pa as the threshold for Level B behavioral harassment 
from impulses noise.
    The acoustic source level of the proposed 3,280 in\3\ seismic 
source array was predicted using JASCO's airgun array source model 
(AASM) based on data collected from three sites chosen in the project 
area by JASCO. Water depths at the three sites were 17, 40, and 100 m. 
JASCO applied its Marine Operations Noise Model (MONM) to estimate 
acoustic propagation of the proposed seismic source array and the 
associated distances to the 190, 180 and 160 dB (rms) re 1 [mu]Pa 
isopleths relative to standard NMFS mitigation and monitoring 
requirements for marine mammals. The resulting isopleths modeled for 
the 180 and 190 dB (rms) re 1 [mu]Pa exclusion zone distances for 
cetaceans and pinnipeds, respectively, differed with the three water 
depths. An additional 10 percent distance buffer was added by JASCO to 
these originally modeled distances to provide larger, more protective 
exclusion zone radii. The modeled exclusion zones and zones of 
influence are listed in Table 1.
    These safety distances will be implemented at the commencement of 
2013 airgun operations to establish marine mammal exclusion zones used 
for mitigation. TGS will conduct sound source measurements of the 
airgun array at the beginning of survey operations in 2013 to verify 
the size of the various marine mammal exclusion zones. The acoustic 
data will be analyzed as quickly as reasonably practicable in the field 
and used to verify and adjust the marine mammal exclusion zone 
distances. The mitigation measures to be implemented at the 190 and 180 
dB (rms) sound levels will include power downs and shut downs as 
described below.

(2) Vessel Related Mitigation Measures

    These mitigation measures apply to all vessels that are part of the 
Chukchi Sea seismic survey activities, including the supporting vessel.
     Avoid concentrations or groups of whales by all vessels 
under the direction of TGS. Operators of vessels should, at all times, 
conduct their activities at the maximum distance possible from such 
concentrations of whales.
     Vessels in transit shall be operated at speeds necessary 
to ensure no physical contact with whales occurs. If any vessel 
approaches within 1.6 km (1 mi) of observed bowhead whales, except when 
providing emergency assistance to whalers or in other emergency 
situations, the vessel operator will take reasonable precautions to 
avoid potential interaction with the bowhead whales by taking one or 
more of the following actions, as appropriate:
    [cir] Reducing vessel speed to less than 5 knots within 300 yards 
(900 feet or 274 m) of the whale(s);
    [cir] Steering around the whale(s) if possible;
    [cir] Operating the vessel(s) in such a way as to avoid separating 
members of

[[Page 51160]]

a group of whales from other members of the group;
    [cir] Operating the vessel(s) to avoid causing a whale to make 
multiple changes in direction; and
    [cir] Checking the waters immediately adjacent to the vessel(s) to 
ensure that no whales will be injured when the propellers are engaged.
     Reduce vessel speed to 5 knots when weather conditions 
require, such as when visibility drops, to avoid the likelihood of 
injury to whales.

(3) Mitigation Measures for Airgun Operations

    The primary role for airgun mitigation during the seismic surveys 
is to monitor marine mammals near the airgun array during all daylight 
airgun operations and during any nighttime start-up of the airguns. 
During the seismic surveys PSOs will monitor the pre-established 
exclusion zones for the presence of marine mammals. When marine mammals 
are observed within, or about to enter, designated safety zones, PSOs 
have the authority to call for immediate power down (or shutdown) of 
airgun operations as required by the situation. A summary of the 
procedures associated with each mitigation measure is provided below.
Ramp Up Procedure
    A ramp up of an airgun array provides a gradual increase in sound 
levels, and involves a step-wise increase in the number and total 
volume of airguns firing until the full volume is achieved. The purpose 
of a ramp up (or ``soft start'') is to ``warn'' cetaceans and pinnipeds 
in the vicinity of the airguns and to provide time for them to leave 
the area and thus avoid any potential injury or impairment of their 
hearing abilities.
    During the open-water survey program, the seismic operator will 
ramp up the airgun arrays slowly. Full ramp ups (i.e., from a cold 
start after a shut down, when no airguns have been firing) will begin 
by firing a single airgun in the array (i.e., the mitigation airgun). A 
full ramp up, after a shut down, will not begin until there has been a 
minimum of 30 min of observation of the safety zone by PSOs to assure 
that no marine mammals are present. The entire exclusion zone must be 
visible during the 30-minute lead-in to a full ramp up. If the entire 
exclusion zone is not visible, then ramp up from a cold start cannot 
begin. If a marine mammal(s) is sighted within the safety zone during 
the 30-minute watch prior to ramp up, ramp up will be delayed until the 
marine mammal(s) is sighted outside of the exclusion zone or the 
animal(s) is not sighted for at least 15-30 minutes: 15 minutes for 
small odontocetes (harbor porpoise) and pinnipeds, or 30 minutes for 
baleen whales and large odontocetes (including beluga and killer whales 
and narwhal).
Use of a Small-Volume Airgun During Turns and Transits
    Throughout the seismic survey, particularly during turning 
movements, and short transits, TGS will employ the use of a small-
volume airgun (i.e., 60 in\3\ ``mitigation airgun''). The mitigation 
airgun would be operated at approximately one shot per minute and would 
not be operated for longer than three hours in duration during daylight 
hours and good visibility. In cases when the next start-up after the 
turn is expected to be during lowlight or low visibility, use of the 
mitigation airgun may be initiated 30 minutes before darkness or low 
visibility conditions occur and may be operated until the start of the 
next sail line. The mitigation gun must still be operated at 
approximately one shot per minute.
    During turns or brief transits (e.g., less than three hours) 
between seismic tracklines, one mitigation airgun will continue 
operating. The ramp-up procedure will still be followed when increasing 
the source levels from one airgun to the full airgun array. However, 
keeping one airgun firing will avoid the prohibition of a ``cold 
start'' during darkness or other periods of poor visibility. Through 
use of this approach, seismic surveys using the full array may resume 
without the 30 minute observation period of the full exclusion zone 
required for a ``cold start''. PSOs will be on duty whenever the 
airguns are firing during daylight, during the 30 minute periods prior 
to ramp-ups.
Power-Down and Shut Down Procedures
    A power down is the immediate reduction in the number of operating 
energy sources from all firing to some smaller number (e.g., single 
mitigation airgun). A shut down is the immediate cessation of firing of 
all energy sources. The array will be immediately powered down whenever 
a marine mammal is sighted approaching close to or within the 
applicable safety zone of the full array, but is outside the applicable 
safety zone of the single mitigation source. If a marine mammal is 
sighted within or about to enter the applicable safety zone of the 
single mitigation airgun, the entire array will be shut down (i.e., no 
sources firing).
Poor Visibility Conditions
    TGS plans to conduct 24-hour operations. PSOs will not be on duty 
during ongoing seismic operations during darkness, given the very 
limited effectiveness of visual observation at night (there will be no 
periods of darkness in the survey area until mid-August). The 
provisions associated with operations at night or in periods of poor 
visibility include the following:
     If during foggy conditions, heavy snow or rain, or 
darkness (which may be encountered starting in late August), the full 
180 dB exclusion zone is not visible, the airguns cannot commence a 
ramp-up procedure from a full shut-down.
     If one or more airguns have been operational before 
nightfall or before the onset of poor visibility conditions, they can 
remain operational throughout the night or poor visibility conditions. 
In this case ramp-up procedures can be initiated, even though the 
exclusion zone may not be visible, on the assumption that marine 
mammals will be alerted by the sounds from the single airgun and have 
moved away.

(4) Mitigation Measures for Subsistence Activities

    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 
activities that take place in Arctic waters to provide a Plan of 
Cooperation (POC) or information that identifies what measures have 
been taken and/or will be taken to minimize adverse effects on the 
availability of marine mammals for subsistence purposes.
    TGS has prepared a POC, which relies upon the Chukchi Sea 
Communication Plans to identify the measures that TGS has developed in 
consultation with North Slope subsistence communities and will 
implement during its planned 2013 activities to minimize any adverse 
effects on the availability of marine mammals for subsistence uses. The 
POC describes important subsistence activities near the proposed survey 
program and summarizes actions TGS has taken to inform subsistence 
communities of the proposed survey activities; and measures it will 
take to minimize adverse effects on marine mammals where proposed 
activities may affect the availability of a species or stock of marine 
mammals for arctic subsistence uses or near a traditional subsistence 
hunting area.
    TGS began stakeholder engagement by introducing the project to the 
North Slope Borough (NSB) Planning Commission on October 25, 2012, and 
it also met with the NSB Planning Director and other Barrow leadership. 
In

[[Page 51161]]

December 2012, TGS met with Chukchi Sea community leaders at the 
tribal, city, and corporate level in Barrow, Wainwright, Point Hope, 
Point Lay, and Kotzebue. TGS also introduced the project to the Alaska 
Eskimo Whaling Commission (AEWC) at their 4th Quarter Meeting on 
December 13-14, 2012, in Anchorage.
    Community POC meetings were held in Barrow, Kotzebue, Point Hope, 
Point Lay, and Wainwright in January and February 2013. Finally, in 
February 2013, TGS participated in the AEWC mini-convention and 
Conflict Avoidance Agreement (CAA) discussion. A final POC that 
documents all consultations with community leaders and subsistence 
users was submitted to NMFS in May, 2013.
    In addition, TGS signed a CAA with the Alaska whaling communities 
to further ensure that its proposed open-water seismic survey 
activities in the Chukchi Sea will not have unmitigable impacts to 
subsistence activities. NMFS has included appropriate measures 
identified in the CAA in the IHA.
Mitigation Conclusions
    NMFS has carefully evaluated the mitigation measures and considered 
a range of other measures in the context of ensuring that NMFS 
prescribes the means of effecting the least practicable impact on the 
affected marine mammal species and stocks and their habitat. Our 
evaluation of potential measures included consideration of the 
following factors in relation to one another:
     The manner in which, and the degree to which, the 
successful implementation of the measure is expected to minimize 
adverse impacts to marine mammals; and
     the practicability of the measure for applicant 
implementation.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
required mitigation measures provide the means of effecting the least 
practicable impact on marine mammal species or stocks and their 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance.

Monitoring and Reporting Measures

    In order to issue an ITA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking''. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for ITAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present in the proposed action area.

I. Monitoring Measures

    Monitoring will provide information on the numbers of marine 
mammals potentially affected by the exploration operations and 
facilitate real time mitigation to prevent injury of marine mammals by 
industrial sounds or activities. These goals will be accomplished in 
the Chukchi Sea during 2013 by conducting vessel-based monitoring from 
both the source vessel and a supporting vessel and an acoustic 
monitoring program using a towed hydrophone array to document marine 
mammal presence and distribution in the vicinity of the survey area 
beyond visual observation distances.
    Visual monitoring by Protected Species Observers (PSOs) during 
seismic operations, and periods when these surveys are not occurring, 
will provide information on the numbers of marine mammals potentially 
affected by these activities and facilitate real time mitigation to 
prevent impacts to marine mammals by industrial sounds or operations. 
Vessel-based PSOs onboard the survey vessel will record the numbers and 
species of marine mammals observed in the area and any observable 
reaction of marine mammals to the survey activities in the Chukchi Sea.
    Real-time PAM would be conducted from the supporting vessel to 
complement the visual monitoring conducted by PSOs during the seismic 
surveys in the Chukchi Sea. Studies have indicated that towed PAM is a 
practical and successful application for augmenting visual surveys of 
low-frequency mysicetes, including blue and fin whales (Clark and 
Fristrup 1997). Passive acoustics methods, including towed hydrophone 
arrays, are most effective in remote areas, harsh environments (e.g. 
the arctic) and when visibility and/or sea conditions are poor, or at 
nighttime or during low-light conditions when animals cannot be sighted 
easily. Surveys have collected more acoustic detections than visual 
observations while using towed PAM in the Arctic during an open-water 
seismic survey program conducted by Statoil in 2010 (McPherson et al. 
2012). TGS states that the designed PAM system would provide the 
possibility of advanced real-time notification of vocalizing marine 
mammals that are not observed visually (or are observed after acoustic 
detection) and allow for mitigation actions (i.e., power-down, shut-
down) to take place, if necessary.
Visual-Based Protected Species Observers (PSOs)
The visual-based marine mammal monitoring will be implemented by a team 
of experienced PSOs, including both biologists and Inupiat personnel. 
PSOs will be stationed aboard the survey and supporting vessels through 
the duration of the project. The vessel-based marine mammal monitoring 
will provide the basis for real-time mitigation measures as discussed 
in the Mitigation Measures section. In addition, monitoring results of 
the vessel-based monitoring program will include the estimation of the 
number of ``takes'' as stipulated in the IHA.
(1) Protected Species Observers
    Vessel-based monitoring for marine mammals will be done by trained 
PSOs throughout the period of survey activities. The observers will 
monitor the occurrence of marine mammals near the survey vessel during 
all daylight periods during operation, and during most daylight periods 
when operations are not occurring. PSO duties will include watching for 
and identifying marine mammals; recording their numbers, distances, and 
reactions to the survey operations; and documenting ``take by 
harassment''.
    A sufficient number of PSOs will be required onboard the survey 
vessel to meet the following criteria:
     100% Monitoring coverage during all periods of survey 
operations in daylight;
     maximum of 4 consecutive hours on watch per PSO; and
     maximum of 12 hours of watch time per day per PSO.
    PSO teams will consist of Inupiat observers and experienced field 
biologists. Each vessel will have an experienced field crew leader to 
supervise the PSO team. The total number of PSOs may decrease later in 
the season as the duration of daylight decreases.
(2) Observer Qualifications and Training
    Crew leaders and most PSOs will be individuals with experience as 
observers during recent seismic, site clearance and shallow hazards, 
and other monitoring projects in Alaska or other offshore areas in 
recent years.
    Biologist-observers will have previous marine mammal observation 
experience, and field crew leaders will be highly experienced with 
previous vessel-based marine mammal monitoring and mitigation projects. 
Resumes for those individuals will be provided to NMFS

[[Page 51162]]

for review and acceptance of their qualifications. Inupiat observers 
will be experienced in the region and familiar with the marine mammals 
of the area. All observers will complete a NMFS-approved observer 
training course designed to familiarize individuals with monitoring and 
data collection procedures.
    PSOs will complete a two or three-day training and refresher 
session on marine mammal monitoring, to be conducted shortly before the 
anticipated start of the 2013 open-water season. Any exceptions will 
have or receive equivalent experience or training. The training 
session(s) will be conducted by qualified marine mammalogists with 
extensive crew-leader experience during previous vessel-based seismic 
monitoring programs.
Marine Mammal Observer Protocol
    Vessel-based visual monitoring for marine mammals shall be 
conducted by NMFS-approved PSOs throughout the period of survey 
activities, and extends to 30 minutes after the survey is completed. 
The PSOs will watch for marine mammals from the best available vantage 
point on the survey vessels, typically the bridge. The PSOs will scan 
systematically with the unaided eye and 7 x 50 reticle binoculars, 
supplemented with 20 x 60 image-stabilized Zeiss Binoculars or Fujinon 
25 x 150 ``Big-eye'' binoculars, and night-vision equipment when 
needed. Personnel on the bridge will assist the marine mammal 
observer(s) in watching for marine mammals.
    The observer(s) aboard the survey and support vessels will give 
particular attention to the areas within the marine mammal exclusion 
zones around the source vessel. These zones are the maximum distances 
within which received levels may exceed 180 dB (rms) re 1 [micro]Pa 
(rms) for cetaceans, or 190 dB (rms) re 1 [micro]Pa for pinnipeds.
    Distances to nearby marine mammals will be estimated with 
binoculars (Fujinon 7 x 50 binoculars) containing a reticle to measure 
the vertical angle of the line of sight to the animal relative to the 
horizon. Observers may use a laser rangefinder to test and improve 
their abilities for visually estimating distances to objects in the 
water.
    When a marine mammal is seen approaching or within the exclusion 
zone applicable to that species, the seismic survey crew will be 
notified immediately so that mitigation measures called for in the 
applicable authorization(s) can be implemented.
    Night-vision equipment (Generation 3 binocular image intensifiers 
or equivalent units) will be available for use when/if needed. In TGS' 
Marine Mammal Monitoring and Mitigation Plan submitted in May 2013, TGS 
stated that it would use the ITT F500 Series Generation 3 binocular 
image intensifiers or equivalent units. However, TGS later notified 
NMFS that such technology is restrict for export and thus cannot be 
carried to high seas. Therefore, Generation 1 night-vision devices 
(NVDs) will be used instead. Since the low-light hours during TGS' 
survey period is very limited, and there is strict mitigation measures 
prohibiting airgun ramp up from cold start when the entire exclusion 
zones are not visible, NMFS considers that the unavailability of 
Generation 3 NVDs does not compromise the effectiveness of mitigation 
measures. Past experience with night-vision devices (NVDs) in the 
Chukchi Sea and elsewhere has indicated that NVDs are not nearly as 
effective as visual observation during daylight hours (e.g., Harris et 
al. 1997, 1998; Moulton and Lawson 2002).
Field Data-Recording
    The PSOs aboard the vessels will maintain a digital log of seismic 
surveys, noting the date and time of all changes in seismic activity 
(ramp-up, power-down, changes in the active seismic source, shutdowns, 
etc.) and any corresponding changes in monitoring radii in a project-
customized Mysticetus\TM\ observation software spreadsheet. In 
addition, PSOs will utilize this standardized format to record all 
marine mammal observations and mitigation actions (seismic source 
power-downs, shut-downs, and ramp-ups). Information collected during 
marine mammal observations will include the following:
     Vessel speed, position, and activity
     Date, time, and location of each marine mammal sighting
     Number of marine mammals observed, and group size, sex, 
and age categories
     Observer's name and contact information
     Weather, visibility, and ice conditions at the time of 
observation
     Estimated distance of marine mammals at closest approach
     Activity at the time of observation, including possible 
attractants present
     Animal behavior
     Description of the encounter
     Duration of encounter
     Mitigation action taken
    Data will preferentially be recorded directly into handheld 
computers or as a back-up, transferred from hard-copy data sheets into 
an electronic database. A system for quality control and verification 
of data will be facilitated by the pre-season training, supervision by 
the lead PSOs, in-season data checks, and will be built into the 
Mysticetus\TM\ software (i.e., Mysticetus\TM\ will recognize and notify 
the operator if entered data are non-sensical). Computerized data 
validity checks will also be conducted, and the data will be managed in 
such a way that it is easily summarized during and after the field 
program and transferred into statistical, graphical, or other programs 
for further processing. Mysticetus\TM\ will be used to quickly and 
accurately summarize and display these data.
Passive Acoustic Monitoring
(1) Sound Source Measurements
    Prior to or at the beginning of the seismic survey, sound levels 
will be measured as a function of distance and direction from the 
proposed seismic source array (full array and reduced to a single 
mitigation airgun). Results of the acoustic characterization and SSV 
will be used to empirically refine the modeled distance estimates of 
the pre-season 190 dB, 180 dB, and 160 dB isopleths. The refined SSV 
exclusion zones will be used for the remainder of the seismic survey. 
Distance estimates for the 120 dB isopleth will also be modeled. The 
results of the SSV will be submitted to NMFS within five days after 
completing the measurements, followed by a report in 14 days. A more 
detailed report will be provided to NMFS as part of the 90-day report 
following completion of the acoustic program.
    (2) Real-Time Passive Acoustic Monitoring
    TGS will conduct real-time passive acoustic monitoring using a 
towed hydrophone array from the support vessel. The towed hydrophone 
array system consists of two parts: the ``wet end'' and the ``dry 
end''. The wet end consists of the hydrophone array and tow cable that 
is towed behind the vessel. The dry end includes the analog-to-digital, 
computer processing, signal conditioning and filtering system used to 
process, record and analyze the acoustic data. Specific noise filters 
will be used to maximize the systems ability to detect low frequency 
bowhead whales. The towed hydrophone array will be deployed using a 
winch from the scout vessel. Details and specifications on the 
equipment will be determined at a later date once TGS has selected an 
acoustics contractor, as each contractor has different equipment 
specifications.
    Localization of vocalizing animals will be accomplished using 
target motion analysis. With this method, it is possible with a single 
towed

[[Page 51163]]

hydrophone array to obtain a localization to vocalizing animals given 
certain assumptions. Due to the linear alignment of hydrophones, there 
is a left/right ambiguity that cannot be resolved without turning the 
tow vessel. The left/right ambiguity, however, is not a critical 
concern for mitigation during the TGS 2D seismic survey because the 
exclusion zones are circular; therefore, the distance to the calling 
animal is the same on the right and left side of the vessel. 
Furthermore, unambiguous localization can be achieved in circumstances 
where the vessel towing the array can turn and the calling animals call 
multiple times or continuously.
    To ensure the effectiveness of real-time PAM with a towed 
hydrophone array, the following requirements for PAM design and 
procedures will be required:
Lowering Interferences From Flow Noise
     Limit towing speeds to 4-6 knots. Reduce speed 
appropriately if bowhead whales are detected so that bearing can be 
obtained. If greater speeds are necessary, slow down every 20-30 
minutes to listen for animal calls for at least 5-10 minutes.
     Maintain straight track-lines unless right/left ambiguity 
must be resolved (usually by turning 20-30 degrees at a time, then 
maintaining a straight course until good bearings can be obtained).
     Maintain a separation distance of at least several hundred 
meters (preferably more) from the seismic survey vessel.
     Design pre-amplifier filters that are `tuned' to reduce 
low[hyphen]frequency flow and vessel noise.
     If necessary, use a variable high-pass filter before 
digitizing the signals.
Monitoring Marine Mammal Occurrence Within 160 dB Isopleths
     Design a hydrophone array that is sensitive to frequencies 
of interest (e.g. marine mammal sounds) but attenuates (via filters) 
noise.
     Use a processing system that can further signal conditions 
(i.e. filter and match signal gains) to allow software to effectively 
estimate bearings and/or localize.
     Use software designed exclusively for monitoring, 
localizing and plotting marine mammal calls.
     Design the sampling software to optimize overlap between 
monitoring the 180 and 160 dB isopleths.
     Allow the survey vessel to deviate from designated 
track[hyphen]lines by 25-30 degrees (for brief periods) so that left/
right ambiguity can be resolved.
Increase Localization Capability
     Start with a simple hydrophone array, and if needed, add 
additional capabilities (or hydrophones) to supplement this system. For 
example, a 2[hyphen]hydrophone array that can do TMA but with an 
additional array (or inline section) that can be added in front of the 
primary array would allow crossed[hyphen]pair localization methods to 
be used.
     Use a processing and geographic display system that can 
accommodate at least the TMA localization method, but also, additional 
methods if needed.
     Provide at least 300 m of cable (for TMA methods), and up 
to 500 m if crossed[hyphen]pair or hyperbolic localization methods will 
be used.
Monitoring Plan Peer Review
    The MMPA requires that monitoring plans be independently peer 
reviewed ``where the proposed activity may affect the availability of a 
species or stock for taking for subsistence uses'' (16 U.S.C. 
1371(a)(5)(D)(ii)(III)). Regarding this requirement, NMFS' implementing 
regulations state, ``Upon receipt of a complete monitoring plan, and at 
its discretion, [NMFS] will either submit the plan to members of a peer 
review panel for review or within 60 days of receipt of the proposed 
monitoring plan, schedule a workshop to review the plan'' (50 CFR 
216.108(d)).
    NMFS convened an independent peer review panel to review TGS' 
mitigation and monitoring plan in its IHA application for taking marine 
mammals incidental to the proposed open-water seismic survey in the 
Chukchi Sea during 2013. The panel met on January 8 and 9, 2013, and 
provided their final report to NMFS in March 2013. The full panel 
report can be viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    NMFS provided the panel with TGS' monitoring and mitigation plan 
and asked the panel to address the following questions and issues for 
TGS' plan:
     Will the applicant's stated objectives effectively further 
the understanding of the impacts of their activities on marine mammals 
and otherwise accomplish the goals stated below? If not, how should the 
objectives be modified to better accomplish the goals above?
     Can the applicant achieve the stated objectives based on 
the methods described in the plan?
     Are there technical modifications to the proposed 
monitoring techniques and methodologies proposed by the applicant that 
should be considered to better accomplish their stated objectives?
     Are there techniques not proposed by the applicant (i.e., 
additional monitoring techniques or methodologies) that should be 
considered for inclusion in the applicant's monitoring program to 
better accomplish their stated objectives?
     What is the best way for an applicant to present their 
data and results (formatting, metrics, graphics, etc.) in the required 
reports that are to be submitted to NMFS (i.e., 90-day report and 
comprehensive report)?
    The peer review panel report contains recommendations that the 
panel members felt were applicable to the TGS' monitoring plans. The 
panel agrees that the objective of vessel-based monitoring to implement 
mitigation measures to prevent or limit Level A takes is appropriate. 
In addition, at the time the panel reviewed the TGS' proposed marine 
mammal monitoring and mitigation plan, TGS only proposed vessel-based 
visual monitoring (but subsequently added PAM as described above). The 
panel was particularly concerned that there are considerable 
limitations to the ability of PSOs to monitor the full extent of the 
zones of influence, as these zones extend to as far as 15 km beyond the 
source. In addition, the panel pointed out that TGS did not specify how 
it planned to operate the scout vessel for marine mammal monitoring.
    Specific recommendations provided by the peer review panel to 
enhance marine mammal monitoring, especially far distance monitoring 
beyond exclusion zones, include: (1) Implementing passive acoustic 
monitoring, with bottom mounted passive acoustic recorders probably 
being the most appropriate method; (2) deploying a real-time, passive 
acoustic monitoring device that is linked by satellite (i.e., Iridium) 
phone; (3) collaborating with NMFS to use aerial survey data for 
assessing marine mammal distribution, relative abundance, behavior, and 
possible impacts relative to seismic surveys; (4) looking into the 
possibility of using unmanned aerial systems to survey for marine 
mammals in offshore areas; and (5) utilizing new technologies, such as 
underwater vehicles, gliders, satellite monitoring, etc., to conduct 
far-field monitoring.
    NMFS discussed extensively with TGS ways to improve far-field 
marine mammal monitoring. As a result, upon further investigation and 
conversations with both JASCO and Bio-Waves by TGS, as well as further 
research into past Arctic marine mammal monitoring results conducted 
with towed-PAM, NMFS and TGS agree that utilizing a

[[Page 51164]]

well-designed towed-PAM system would meet the need to provide enhanced 
marine mammal monitoring beyond exclusion zones, as well as using 
acoustic data for limited relative abundance and distribution analysis, 
and possibly limited insights on impacts to marine mammals.
    NMFS also studied other PAM methodologies suggested by the peer-
review panel. First, concerning deploying fixed bottom mounted 
recorders, TGS states that it has been in contact with other operators 
but was not able to find a collaborator to participate in long-term 
acoustic monitoring due to the short-term nature of the proposed 
survey. Regarding the real-time acoustic monitoring with fixed buoy, 
TGS stated that it conducted an evaluation of this option and discussed 
the possibility with the Cornell University's Bioacoustical Research 
Program concerning its real-time marine acoustic recording unit (MARU), 
but decided that the technology is still in the research and 
development stage. TGS also states that it did not consider the 
technology because the cost is more expensive than other PAM methods. 
TGS also discussed (with NMFS scientists) the possibility of using 
NMFS' aerial survey data for assessing marine mammal distribution, 
relative abundance, and possible impacts relative to seismic surveys. 
However, most of TGS' survey areas are outside NMFS aerial survey area, 
which makes it impossible to use these datasets for impact analyses. 
TGS also did a cost-benefit analysis of manned aerial surveys, and 
eliminated this as an option due to increased health and safety 
exposure risk, especially north of 72[deg]N. TGS also investigated the 
possibility of using unmanned aerial vehicles (UAV) to survey for 
marine mammals in offshore areas, however, it has also turned out not 
to be feasible due to the fact that the approach is currently awaiting 
an FAA permit to operate in the Arctic, and this permit could not be 
guaranteed to be obtained in time for the TGS monitoring effort. TGS 
states that it did consider new technologies, but did not feel that 
they could justify the expense of testing techniques with unknown 
capabilities in the Arctic environment.
    In addition, the panel also recommends that TGS collaborate with 
other organizations operating in the Chukchi Sea and share visual and 
acoustic data to improve understanding of impacts from single and 
multiple operations and efficacy of mitigation measures. Accordingly, 
TGS plans to share these data via the OBIS-SEAMAP Web site entertaining 
all appropriate data-sharing agreements, including data obtained using 
towed PAM.

II. Reporting Measures

1. Sound Source Verification Reports
    A report on the preliminary results of the sound source 
verification measurements, including the measured 190, 180, and 160 dB 
(rms) radii of the airgun sources, would be submitted within 14 days 
after collection of those measurements at the start of the field 
season. This report will specify the distances of the exclusion zones 
that were adopted for the survey.
2. Field Reports
    Throughout the survey program, PSOs will prepare a report each day 
or at such other intervals, summarizing the recent results of the 
monitoring program. The reports will summarize the species and numbers 
of marine mammals sighted. These reports will be provided to NMFS and 
to the survey operators.
3. Technical Reports
    The results of TGS' 2013 vessel-based monitoring, including 
estimates of ``take'' by harassment, would be presented in the ``90-
day'' and Final Technical reports, if the IHA is issued for the 
proposed open-water 2D seismic surveys. The Technical Reports should be 
submitted to NMFS within 90 days after the end of the seismic survey. 
The Technical Reports will include:
    (a) Summaries of monitoring effort (e.g., total hours, total 
distances, and marine mammal distribution through the study period, 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals);
    (b) Analyses of the effects of various factors influencing 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog/glare);
    (c) Species composition, occurrence, and distribution of marine 
mammal sightings, including date, water depth, numbers, age/size/gender 
categories (if determinable), group sizes, and ice cover;
    (d) To better assess impacts to marine mammals, data analysis 
should be separated into periods when a seismic airgun array (or a 
single mitigation airgun) is operating and when it is not. Final and 
comprehensive reports to NMFS should summarize and plot:
     Data for periods when a seismic array is active and when 
it is not; and
     The respective predicted received sound conditions over 
fairly large areas (tens of km) around operations;
    (e) Sighting rates of marine mammals during periods with and 
without airgun activities (and other variables that could affect 
detectability), such as:
     initial sighting distances versus airgun activity state;
     closest point of approach versus airgun activity state;
     observed behaviors and types of movements versus airgun 
activity state;
     numbers of sightings/individuals seen versus airgun 
activity state;
     distribution around the survey vessel versus airgun 
activity state; and
     estimates of take by harassment;
    (f) Reported results from all hypothesis tests should include 
estimates of the associated statistical power when practicable;
    (g) Estimate and report uncertainty in all take estimates. 
Uncertainty could be expressed by the presentation of confidence 
limits, a minimum-maximum, posterior probability distribution, etc.; 
the exact approach would be selected based on the sampling method and 
data available;
    (h) The report should clearly compare authorized takes to the level 
of actual estimated takes; and
    (i) Methodology used to estimate marine mammal takes and relative 
abundance on towed PAM.
4. Notification of Injured or Dead Marine Mammals
    In addition, NMFS would require TGS to notify NMFS' Office of 
Protected Resources and NMFS' Stranding Network within 48 hours of 
sighting an injured or dead marine mammal in the vicinity of seismic 
survey operations. TGS shall provide NMFS with the species or 
description of the animal(s), the condition of the animal(s) (including 
carcass condition if the animal is dead), location, time of first 
discovery, observed behaviors (if alive), and photo or video (if 
available).
    In the event that an injured or dead marine mammal is found by TGS 
that is not in the vicinity of the proposed open-water seismic survey 
program, TGS would report the same information as listed above as soon 
as operationally feasible to NMFS.

Estimated Take by Incidental 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,

[[Page 51165]]

feeding, or sheltering [Level B harassment]. Only take by Level B 
behavioral harassment is anticipated as a result of the proposed open-
water seismic survey program. Anticipated impacts to marine mammals are 
associated with noise propagation from the survey airgun(s) used in the 
seismic surveys.
    The full suite of potential impacts to marine mammals was described 
in detail in the ``Potential Effects of the Specified Activity on 
Marine Mammals'' section found earlier in this document. The potential 
effects of sound from the proposed open-water seismic survey programs 
might include one or more of the following: masking of natural sounds; 
behavioral disturbance; non-auditory physical effects; and, at least in 
theory, temporary or permanent hearing impairment (Richardson et al. 
1995). As discussed earlier in this document, the most common impact 
will likely be from behavioral disturbance, including avoidance of the 
ensonified area or changes in speed, direction, and/or diving profile 
of the animal. For reasons discussed previously in this document, 
hearing impairment (TTS and PTS) is highly unlikely to occur based on 
the mitigation and monitoring measures that would preclude marine 
mammals from being exposed to noise levels high enough to cause hearing 
impairment.
    For impulse sounds, such as those produced by airgun(s) used in the 
2D seismic surveys, NMFS uses the 160 dB (rms) re 1 [mu]Pa isopleth to 
indicate the onset of Level B harassment. TGS provided calculations for 
the 160-dB isopleths produced by the proposed seismic surveys and then 
used those isopleths to estimate takes by harassment. NMFS used the 
calculations to make the necessary MMPA findings. TGS provided a full 
description of the methodology used to estimate takes by harassment in 
its IHA application, which is also provided in the following sections.

Basis for Estimating ``Take by Harassment''

    The estimated takes by harassment is calculated in this section by 
multiplying the expected densities of marine mammals that may occur 
near the planned activities by the area of water likely to be exposed 
to impulse sound levels of >=160 dB (rms) re 1 [mu]Pa.
    Marine mammal occurrence near the operation is likely to vary by 
season and habitat, mostly related to the presence or absence of sea 
ice. Although current NMFS' noise exposure standards state that Level B 
harassment occurs at exposure levels >=160 dB (rms) re 1 [mu]Pa by 
impulse sources, there is no evidence that avoidance at these received 
sound levels would have significant biological effects on individual 
animals. Any changes in behavior caused by sounds at or near the 
specified received levels would likely fall within the normal variation 
in such activities that would occur in the absence of the planned 
operations. However, these received levels are currently used to set 
the threshold for Level B behavioral harassment.

Marine Mammal Density Estimates

    The first step in estimating the number of marine mammals that 
might be ``taken by harassment'' was to conduct a review of available 
data on density estimates for the marine mammal species occurring in 
the project vicinity and adjacent areas of the Chukchi Sea. While 
several densities are available for U.S. waters in the Chukchi Sea, no 
reliable estimates are known for U.S. waters north of 72[deg] N. 
Furthermore, no systematic surveys are known for the western half of 
the proposed project area in international waters.
    Therefore, densities used to estimate exposures were based on two 
recent IHA applications and three 90-day reports to NMFS summarizing 
results of field monitoring surveys. These project areas overlapped the 
proposed TGS project area to at least some extent as well as TGS' 
proposed seismic operations period. A map showing the boundaries of 
these survey areas relative to TGS' proposed seismic line locations is 
provided in Figure 2 of TGS' IHA application. The surveys consisted of 
the (1) Two Statoil 90-day reports from the northern Chukchi Sea (Blees 
et al. 2010; Hartin et al. 2011), (2) UAGI's IHA (LGL 2011) and 90-day 
report (Cameron et al. 2012), and (3) Shell 2012 IHA (Shell 2011). 
These data are considered the ``best available'' density estimates and 
occurrence data currently available for the project area.
    All recent density estimates for four different project areas 
overlapping the TGS project area based on the observed or derived 
densities reported in other studies (Blees et al. 2010; Hartin et al. 
2011; LGL 2011; Shell 2011; Cameron et al. 2012) and are shown in Table 
3 of TGS' IHA application. Note that only the Cameron et al. (2012) 
survey occurred north of 72[deg] N in U.S. waters and international 
waters partially overlapping the TGS project area. Sightings providing 
data on observed densities were available for the following six 
species: the bowhead, gray and beluga whale, and the bearded, ringed 
and spotted seal. The remaining other six species occur so rarely in 
the project area vicinity that reliable densities are not available for 
them and/or no sightings were made during the reported surveys: the 
humpback, minke, fin, and killer whales, the harbor porpoise, and the 
ribbon seal (Blees et al. 2010; Hartin et al. 2011; Cameron et al. 
2012). Thus, certain fractional numbers were assigned to them based on 
those reported for other IHAs overlapping the proposed TGS project 
area, to address the rare chance of an encounter (Blees et al. 2010; 
Hartin et al. 2011; LGL 2011; Shell 2011; Cameron et al. 2012).

Adjustment Factors Applied to Provide Lower and Upper Estimates of 
Density

    A number of habitat parameters have been shown to influence the 
distribution of marine mammal species occurring in the TGS project 
area. These parameters were applied to adjust the density of species 
accordingly, as done by other applicants in previous IHA applications 
(e.g., Blees et al. 2010; Hartin et al. 2011; LGL 2011; Shell 2011, 
Cameron et al. 2012). These included (1) open water (i.e., ice-free) 
vs. ice-edge margin (higher densities of pinnipeds and beluga whales 
occur near and/or within the ice margin), (2) summer (July-August) vs. 
fall (September-October), (3) water depth (>200 vs. <200 m deep), and 
(4) likelihood of occurrence above or below 72[deg] N. Open-water 
densities were used if available because TGS operations must completely 
avoid ice to be able to safely and effectively conduct operations.
    Densities (Table 3 in TGS' IHA application) used to estimate and 
calculate the number of exposures to TGS' seismic impulse sound levels 
>=160 dB (rms) re1[mu]Pa were obtained by (1) averaging the densities 
from the four previous studies by summer (July-August), fall 
(September-October), and summer-fall, and then (2) multiplying the 
resulting averaged densities by adjustment factors for water depth 
(shallower or deeper than 200 m) and expected occurrence in waters 
north or south of 72[deg] N. Notably, TGS plans to operate above 
72[deg] N for about half (32 days) of the total 45-60-day period in US 
Federal waters (35 days of which would involve seismic operations), and 
for all operations in international waters, up to 33 days. These 
northern waters above 72[deg] N would be accessed sometime between 
about mid-September and 15 October (when waters are ice-free).
    Because few data were available for most of the survey area, 
particularly north of 72[deg] N and west of Barrow, it is not known how 
closely the applied average densities reflect the actual densities that 
will be encountered

[[Page 51166]]

during the proposed TGS seismic survey. Thus, lower and upper 
adjustment factors (Table 4 in TGS' IHA application) were multiplied by 
the averaged densities to provide a range of density estimates. The 
latter adjustment was incorporated into a formula to estimate exposures 
to seismic sounds. The ``lower adjustment factor'' does not apply 
adjustment factors to densities north of 72[deg] N for the bowhead and 
beluga whale and the ringed and bearded seal. In contrast, the ``upper 
adjustment factor'' applies factors to account for the expected lower 
density of marine mammal species north of 72[deg] N. Adjustment factors 
differed by species and were based on (1) the reported distribution and 
occurrence of each species in these waters, and (2) factors applied by 
ION (LGL 2012) for their 2012 IHA application for the fall period of 
Oct-Dec 2012 that overlapped the fall period (mid-to-late September-
October) and north-easternmost region that TGS expects to operate in 
international waters during fall.
    TGS applied these density data and factors previously applied in an 
IHA issued to ION to account for expected lower densities above 72[deg] 
N where waters are predominantly >1,000 m deep. The upper-adjusted 
(i.e., lower) density estimate was calculated by multiplying reported 
fall densities for more southern Chukchi waters as follows: (1) by a 
factor of 0.0 for fin, humpback, minke and killer whales, and harbor 
porpoise and ribbon and spotted seals as they are not expected in 
waters above 72[deg] N and thus were assumed not to occur there; (2) by 
an adjustment factor of 0.01 for gray whales (since the northernmost 
boundary of their distribution is near 72[deg] N and they are thus 
considered highly unlikely to occur above 72[deg] N; (3) by a factor of 
0.1 for bowhead whales as the area is outside the main migration 
corridor, and (4) by a factor of 0.1 for beluga whales and bearded and 
ringed seals as they are closely associated with ice, and thus 
considered less likely to occur in ice-free waters needed to conduct 
the TGS seismic operations.
    A similar 0.1 adjustment factor was applied in the ION IHA (LGL 
2012) for species where the seismic survey area was on the edge of that 
species' range at the given time of year. ION's adjustment factor of 
0.1 was used for TGS density estimates because TGS proposes to be well 
north and west of ION's westernmost 2012 survey lines no earlier than 
15-30 September through 31 October 2013. In comparison, ION proposed 
their program for 1 October through mid-December, and their actual 
program occurred in the Chukchi and Beaufort Seas from 20 October-9 
November, 2012. These periods overlap the majority of the period that 
TGS is expected to be operating at or near the westernmost seismic 
lines (no earlier than 15-30 September through October) between 
73[deg]-76[deg] N and 160[deg] W to 160[deg] E. Thus, ION's ``late 
season'' period coincides with TGS' proposed late fall season both in 
time and space relative to waters above 72[deg] N.
    The upper density estimates consisted of the averaged fall 
densities for more southern Chukchi waters by only (1) a smaller 
adjustment factor of 0.20 for gray whales (Table 4 of TGS' IHA 
application), and (2) by the same factor of 0.0 for fin, humpback, 
minke and killer whales, and harbor porpoise and ribbon and spotted 
seals as described above.

Additional Rationale for Adjusting Densities North of 72[deg] N

     No whale sightings have been reported in waters north of 
72[deg] N during the few recent vessel-based surveys conducted there 
that overlapped the southern or eastern part of the proposed TGS 
project area and season (Blees et al. 2010; Hartin et al. 2011; Cameron 
et al. 2012).
     The main fall migration corridor for bowheads reportedly 
occurs south of 72[deg] N (Quakenbush et al. 2010). However, satellite-
tagging studies indicate that at least some individual bowheads migrate 
generally west/southwest across the project area in waters above 
72[deg] N and west of Barrow during the fall migration from September-
November (Quakenbush 2007; LGL 2011; Quakenbush et al. 2012).
     The reported gray whale distribution in the Chukchi Sea 
normally does not extend much north of 72[deg] N during summer/fall 
(Jefferson et al. 2008). This northernmost peripheral boundary area is 
thus expected to have very low gray whale densities. Furthermore, most 
gray whales will have migrated south of the project area by fall (Rice 
and Wolman 1971; Allen and Angliss 2012).

Exposure Calculation Methods

    The approach used to calculate the estimated number of individuals 
of each marine mammal species potentially exposed to received levels of 
seismic impulse sound levels >=160 dB (rms) re 1 [mu]Pa during the 
proposed seismic project is described below.
    1. The area of water (in km\2\) ensonified to >=160 dB (rms) re 1 
[mu]Pa around the operating seismic source array on seismic lines as 
well as turns and transits between seismic lines was calculated for 
U.S. and international waters for waters shallower and deeper than 200 
m, and for waters north and south of 72[deg] N (Table 2). It was 
assumed for purposes of this estimation that the full seismic source 
array would be used during all seismic lines and during the 1-km run-in 
and 5-km run-out between seismic lines. In addition, it was assumed 
that a single 60 in\3\ airgun would be used during turns and transits 
between seismic lines. Ensonified waters were calculated as follows.
    2. A buffer was applied on both sides of the planned survey 
tracklines equivalent to the distances modeled for the proposed 3,280 
in\3\ seismic source array by JASCO in 2010 at three locations in the 
project area (Zykov et al. 2013). The buffer width corresponding to 
this 160 (rms) dB re 1 [mu]Pa isopleth varied with three water depth 
categories. Thus, survey tracklines located over waters 17-40 m deep 
were buffered by 8.5 km, those over waters 41-100 m deep were buffered 
by 9.9 km, and those over water depths of >100 m were buffered by 15 
km.

[[Page 51167]]



Table 2--Estimated Area (km\2\) Ensonified to >160 dB (rms) re 1 [mu]Pa by Seismic Impulses Along TGS' 2013 Proposed Seismic Lines and Turns in U.S. and
  International Waters of the Chukchi Sea. Ensonified Areas Assumed That the Full 3,280 in\3\ Array Operated Continuously on Survey Lines and That the
                         Single Mitigation Airgun (60 in\3\) Operated Continuously on Turns (and Transits) Between Survey Lines
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  Above 72[deg]N        Below 72[deg]N      Water depth < 200m    Water depth > 200m   All lines  All turns  All lines &
                              --------------------------------------------------------------------------------------------------------------    turns
                                                                                                                                            ------------
                                 Total      Turns      Total      Turns      Total      Turns      Total      Turns      Total      Total       Total
                                 lines       area      lines       area      lines       area      lines       area      lines      turns     ensonified
                                  area                  area                  area                  area                  area       area        area
                                 (km\2\)    (km\2\)    (km\2\)    (km\2\)    (km\2\)    (km\2\)    (km\2\)    (km\2\)    (km\2\)    (km\2\)      (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
US...........................      65477       1294      72974       1442     114858       2770      23594        466     138452       2736       141188
International................     115135       4200          0          0      45954       1676      69181       2524     115135       4200       119335
                              --------------------------------------------------------------------------------------------------------------------------
    Total....................     180612       5494      72974       1442     160812       3946      92775       2990     253586       6936       260522
--------------------------------------------------------------------------------------------------------------------------------------------------------

    3. A smaller buffer was applied to both sides of turn lines between 
seismic lines equivalent to the measured distance to the 160 dB (rms) 
re 1 [mu]Pa isopleth of a single 60 in\3\ array as measured by JASCO. 
The associated area in km\2\ was calculated using 
MysticetusTM software. MysticetusTM identified 
water depths at 100-m intervals along the survey trackline using 
bathymetric data. At each 100-m interval, MysticetusTM 
applied one of the three aforementioned 160 dB (rms) re 1 [mu]Pa radius 
isopleths corresponding to that water depth. Overlapping areas were 
treated separately. The resulting World Geodetic System (WGS) 84 
polygons were re-projected into North Pole Stereographic coordinates 
and the total area was calculated.
    4. Averaged densities of marine mammals (Table 3 in TGS' IHA 
application) were adjusted as applicable (Table 4 in TGS' IHA 
application) then multiplied by the area predicted to be ensonified to 
>=160 dB (rms) re 1 [mu]Pa. The procedure is outlined below.
     Because TGS expects to conduct seismic lines in U.S. 
Federal waters sometime between mid-July and mid-September in late 
summer and early fall, the proportion of U.S. Federal waters ensonified 
to >160 dB (rms) re 1 [mu]Pa was multiplied by the average of summer 
and fall densities reported from other studies (Table 3 in TGS' IHA 
application).
     Because TGS expects to conduct seismic lines in 
international waters starting in fall from mid-to-late September 
through October, the proportion of international waters ensonified to 
>160 dB (rms) re 1 [mu]Pa was multiplied by the average of fall 
densities reported from other studies (based nearly exclusively on 
surveys south of 72[deg] N since it is considered the best and only 
systematic data available for the region).
     The proportions of ensonified waters north and south of 
72[deg] N were also calculated for U.S. and international waters. 
Species-specific average summer-fall and fall densities associated with 
these depth categories were multiplied by the corresponding proportion 
and season.
     In addition, the proportions of ensonified waters where 
water depth along the seismic line was <200 m deep or >200 m deep were 
calculated. Species-specific average summer-fall and fall densities 
associated with these depth categories were multiplied by the 
corresponding proportion and season.
     Reported fall density estimates for gray, bowhead and 
beluga whales, and bearded and ringed seals were adjusted for ice-free 
waters N of 72[deg] N by multiplying reported fall densities for more 
southern Chukchi waters by low and high adjustment factors described 
above to provide a range of potential exposures.
    In a summary, estimated species exposures are calculated by 
multiplying seasonally (summer vs. fall) and spatially (above vs. below 
72[deg] N at various water depths) marine mammal density by the total 
ensonified areas with received levels higher than 160 dB re 1[mu]Pa 
(rms).

Potential Number of ``Take by Harassment''

    As stated earlier, the estimates of potential Level B takes of 
marine mammals by noise exposure are based on a consideration of the 
number of marine mammals that might be present during operations in the 
Chukchi Sea and the anticipated area exposed to those sound pressure 
levels (SPLs) above 160 dB re 1 [micro]Pa for impulse sources (seismic 
airgun during 2D seismic surveys).
    Some of the animals estimated to be exposed, particularly migrating 
bowhead whales, might show avoidance reactions before being exposed to 
sounds at the specified threshold levels. Thus, these calculations 
actually estimate the number of individuals potentially exposed to the 
specified sounds levels that would occur if there were no avoidance of 
the area ensonified to that level.
    Numbers of marine mammals that might be present and potentially 
taken are summarized in Table 3 based on calculation described above.

  Table 3--Estimates of the Possible Maximum Numbers of Marine Mammals
   Taken by Level B Harassment (Exposed to >=160 dB From Airgun Sound)
 During TGS' Proposed 2D Seismic Survey in the Chukchi Sea, July-October
                                  2013
------------------------------------------------------------------------
                                                  Level B      Percent
                    Species                        takes      population
------------------------------------------------------------------------
Bowhead whale.................................          794         4.70
Gray whale....................................        1,363         7.13
Fin whale.....................................            5         0.09
Humpback whale................................            5         0.53
Minke whale...................................            5         0.62
Beluga whale..................................          412        11.11
Killer whale..................................            5         1.59
Harbor porpoise...............................           36         0.07
Ringed seal...................................       30,000        14.36
Bearded seal..................................         6000         0.84
Spotted seal..................................          500         0.84
Ribbon seal...................................          100         0.20
------------------------------------------------------------------------

Estimated Take Conclusions

    Effects on marine mammals are generally expected to be restricted 
to avoidance of the area around the planned activities and short-term 
changes in behavior, falling within the MMPA definition of ``Level B 
harassment''.
    Cetaceans--The take calculation estimates suggest a total of 794 
bowhead whales may be exposed to sounds at or above 160 dB (rms) re 1 
[micro]Pa (Table 3). This number is approximately 7.53% of the Bering-
Chukchi-Beaufort (BCB) population of 16,892 assessed in 2011 (Givens et 
al. 2013). The total estimated number of gray and beluga whales that

[[Page 51168]]

may be exposed to sounds from the activities ranges up to 1,363 and 
412, respectively (Table 3). Fewer harbor porpoises are likely to be 
exposed to sounds during the activities. The small numbers of other 
whale species that may occur in the Chukchi Sea are unlikely to be 
present around the planned operations but chance encounters may occur. 
The few individuals would represent a very small proportion of their 
respective populations.
    Pinnipeds--Ringed seal is by far the most abundant species expected 
to be encountered during the planned operations. The best estimate of 
the numbers of ringed seals exposed to sounds at the specified received 
levels during the planned activities is 30,000, which represent up to 
14.36% of the Alaska population. Fewer individuals of other pinniped 
species are estimated to be exposed to sounds at Level B behavioral 
harassment level, also representing small proportions of their 
populations.

Negligible Impact and Small Numbers Analysis and Determination

    As a preliminary matter, we typically include our negligible impact 
and small numbers analysis and determination under the same section 
heading of our Federal Register Notices. Despite co-locating these 
terms, we acknowledge that negligible impact and small numbers are 
distinct standards under the MMPA and treat them as such. The analysis 
presented below does not conflate the two standards; instead, each has 
been considered independently and we have applied the relevant factors 
to inform our negligible impact and small numbers determinations.
    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.'' In making a negligible impact determination, 
NMFS considers a variety of factors, including but not limited to: (1) 
The number of anticipated mortalities; (2) the number and nature of 
anticipated injuries; (3) the number, nature, intensity, and duration 
of Level B harassment; and (4) the context in which the takes occur.
    No injuries or mortalities are anticipated to occur as a result of 
TGS' proposed 2013 open-water 2D seismic surveys in the Chukchi Sea, 
and none are being authorized. Additionally, animals in the area are 
not expected to incur hearing impairment (i.e., TTS or PTS) or non-
auditory physiological effects. Takes will be limited to Level B 
behavioral harassment. Although it is possible that some individuals of 
marine mammals may be exposed to sounds from seismic survey activities 
more than once, the expanse of these multi-exposures are expected to be 
less extensive since both the animals and the survey vessels will be 
moving constantly in and out of the survey areas.
    Most of the bowhead whales encountered will likely show overt 
disturbance (avoidance) only if they receive airgun sounds with levels 
>= 160 dB re 1 [mu]Pa. Odontocete reactions to seismic airgun pulses 
are usually assumed to be limited to shorter distances from the 
airgun(s) than are those of mysticetes, probably in part because 
odontocete low-frequency hearing is assumed to be less sensitive than 
that of mysticetes. However, at least when in the Canadian Beaufort Sea 
in summer, belugas appear to be fairly responsive to seismic energy, 
with few being sighted within 6-12 mi (10-20 km) of seismic vessels 
during aerial surveys (Miller et al. 2005). Belugas will likely occur 
in small numbers in the Chukchi Sea during the survey period and few 
will likely be affected by the survey activity.
    As noted, elevated background noise level from the seismic airgun 
reverberant field could cause acoustic masking to marine mammals and 
reduce their communication space. However, even though the decay of the 
signal is extended, the fact that pulses are separated by approximately 
10 seconds means that overall received levels at distance are expected 
to be much lower, thus resulting in less acoustic masking.
    Taking into account the mitigation measures that are planned, 
effects on marine mammals are generally expected to be restricted to 
avoidance of a limited area around TGS' open-water activities and 
short-term changes in behavior, falling within the MMPA definition of 
``Level B harassment''. The many reported cases of apparent tolerance 
by cetaceans of seismic exploration, vessel traffic, and some other 
human activities show that co-existence is possible. Mitigation 
measures such as controlled vessel speed, dedicated marine mammal 
observers, non-pursuit, and shut downs or power downs when marine 
mammals are seen within defined ranges will further reduce short-term 
reactions and minimize any effects on hearing sensitivity. In all 
cases, the effects are expected to be short-term, with no lasting 
biological consequence.
    Of the thirteen marine mammal species likely to occur in the 
seismic survey area, bowhead, fin, and humpback whales and ringed and 
bearded seals are listed as endangered or threatened under the ESA. 
These species are also designated as ``depleted'' under the MMPA. 
Despite these designations, the BCB stock of bowheads has been 
increasing at a rate of 3.4 percent annually for nearly a decade (Allen 
and Angliss 2010). Additionally, during the 2001 census, 121 calves 
were counted, which was the highest yet recorded. The calf count 
provides corroborating evidence for a healthy and increasing population 
(Allen and Angliss 2010). The occurrence of fin and humpback whales in 
the seismic survey areas is considered very rare. There is no critical 
habitat designated in the U.S. Arctic for the bowhead, fin, and 
humpback whales. The Alaska stock of bearded seals, part of the 
Beringia distinct population segment (DPS), and the Arctic stock of 
ringed seals, have recently been listed by NMFS as threatened under the 
ESA. None of the other species that may occur in the project area are 
listed as threatened or endangered under the ESA or designated as 
depleted under the MMPA.
    Potential impacts to marine mammal habitat were discussed 
previously in this document (see the ``Anticipated Effects on Habitat'' 
section). Although some disturbance is possible to food sources of 
marine mammals, the impacts are anticipated to be minor enough as to 
not affect rates of recruitment or survival of marine mammals in the 
area. Based on the vast size of the Arctic Ocean where feeding by 
marine mammals occurs versus the localized area of the seismic survey 
activities, any missed feeding opportunities in the direct project area 
would be minor based on the fact that other feeding areas exist 
elsewhere.
    The authorized take represents 11.11% of the Eastern Chukchi Sea 
population of approximately 3,710 beluga whales, 1.59% of Aleutian 
Island and Bering Sea stock of approximately 314 killer whales, 0.07% 
of Bering Sea stock of approximately 48,215 harbor porpoises, 7.13% of 
the Eastern North Pacific stock of approximately 19,126 gray whales, 
7.53% of the Bering-Chukchi-Beaufort population of 10,545 bowhead 
whales, 0.53% of the Western North Pacific stock of approximately 938 
humpback whales, 0.09% of the Northeast Pacific stock of approximately 
5,700 fin whales, and 0.62% of the Alaska stock of approximately 810 
minke whales. The take estimates presented for ringed, bearded, 
spotted, and ribbon seals represent 14.36, 2.47, 0.84, and 0.20% of 
U.S. Arctic stocks of

[[Page 51169]]

each species, respectively. The mitigation and monitoring measures 
(described previously in this document) included in the IHA are 
expected to reduce even further any potential disturbance to marine 
mammals.
    In addition, no important feeding and reproductive areas are known 
in the vicinity of the TGS' seismic surveys at the time the surveys are 
to take place. No critical habitat of ESA-listed marine mammal species 
occurs in the Chukchi Sea.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the mitigation and monitoring 
measures, NMFS finds that TGS' 2013 open-water 2D seismic surveys in 
the Chukchi Sea may result in the incidental take of small numbers of 
marine mammals, by Level B harassment only, and that the total taking 
from the seismic surveys will have a negligible impact on the affected 
species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    NMFS has determined that TGS' 2013 open-water 2D seismic surveys in 
the Chukchi Sea will not have an unmitigable adverse impact on the 
availability of species or stocks for taking for subsistence uses. This 
determination is supported by information contained in this document 
and TGS' POC. TGS has adopted a spatial and temporal strategy for its 
Chukchi Sea open-water seismic surveys that will help ensure its survey 
will have no unmitigable impacts to subsistence hunters. Due to the 
timing of the project and the distance from the surrounding 
communities, it is anticipated to have no effects on spring harvesting 
and little or no effects on the occasional summer harvest of beluga 
whale, subsistence seal hunts (ringed and spotted seals are primarily 
harvested in winter while bearded seals are hunted during July-
September in the Beaufort Sea), or the fall bowhead hunt.
    In addition, based on the measures described in TGS' POC, the 
required mitigation and monitoring measures (described earlier in this 
document), and the project design itself, NMFS has determined that 
there will not be an unmitigable adverse impact on subsistence uses 
from TGS' 2013 open-water 2D seismic surveys in the Chukchi Sea.

Endangered Species Act (ESA)

    The bowhead, fin, and humpback whales and ringed and bearded seals 
are the only marine mammal species currently listed as endangered or 
threatened under the ESA that could occur during TGS' 2D seismic 
surveys during the Arctic open-water season. NMFS' Permits and 
Conservation Division consulted with NMFS' Alaska Regional Office 
Division of Protected Resources under section 7 of the ESA on the 
issuance of an IHA to TGS under section 101(a)(5)(D) of the MMPA for 
this activity. A Biological Opinion was issued on July 10, 2013, which 
concludes that issuance of the IHA is not likely to jeopardize the 
continued existence of the ESA-listed marine mammal species. NMFS will 
issue an Incidental Take Statement under this Biological Opinion which 
contains reasonable and prudent measures with implementing terms and 
conditions to minimize the effects of take of listed species.

National Environmental Policy Act (NEPA)

    NMFS prepared an EA that includes an analysis of potential 
environmental effects associated with NMFS' issuance of an IHA to TGS 
to take marine mammals incidental to conducting its 2D seismic surveys 
in the Chukchi Sea during the 2013 open-water season. NMFS has 
finalized the EA and prepared a FONSI for this action. Therefore, 
preparation of an EIS is not necessary.

Authorization

    As a result of these determinations, NMFS has issued an IHA to TGS 
to take marine mammals incidental to its 2013 seismic survey in the 
Chukchi Sea, Alaska, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated.

    Dated: August 14, 2013.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2013-20310 Filed 8-19-13; 8:45 am]
BILLING CODE 3510-22-P