[Federal Register Volume 77, Number 206 (Wednesday, October 24, 2012)]
[Notices]
[Pages 65060-65090]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-26103]



[[Page 65059]]

Vol. 77

Wednesday,

No. 206

October 24, 2012

Part II





Department of Commerce





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National Oceanic and Atmospheric Administration





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Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to Marine Seismic Survey in the Beaufort and 
Chukchi Seas, Alaska; Notice

  Federal Register / Vol. 77 , No. 206 / Wednesday, October 24, 2012 / 
Notices  

[[Page 65060]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC091


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Marine Seismic Survey in the 
Beaufort and Chukchi Seas, 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 ION Geophysical (ION) to 
take, by harassment, small numbers of nine species of marine mammals 
incidental to in-ice marine seismic surveys in the Beaufort and Chukchi 
Seas, Alaska, during the fall and winter of 2012.

DATES: Effective October 17, 2011, through December 15, 2012.

ADDRESSES: Requests 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 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 (Secretary) to allow, upon request, 
the incidental, but not intentional taking of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified geographical region if certain findings are 
made and regulations are issued or, if the taking is limited to 
harassment, a notice of a proposed authorization is provided to the 
public for review.
    Authorization shall be granted if NMFS finds that the taking will 
have a negligible impact on the species or stock(s), will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses (where relevant), and if the permissible 
methods of taking and requirements pertaining to the mitigation, 
monitoring and reporting of such taking 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. Except 
with respect to certain activities not pertinent here, the MMPA defines 
``harassment'' as: any act of pursuit, torment, or annoyance which (i) 
has the potential to injure a marine mammal or marine mammal stock in 
the wild [Level A harassment]; or (ii) has the potential to disturb a 
marine mammal or marine mammal stock in the wild by causing disruption 
of behavioral patterns, including, but not limited to, migration, 
breathing, nursing, breeding, feeding, or sheltering [Level B 
harassment].
    Section 101(a)(5)(D) establishes a 45-day time limit for NMFS 
review of an application followed by a 30-day public notice and comment 
period on any proposed authorizations for the incidental harassment of 
marine mammals. Within 45 days of the close of the comment period, NMFS 
must either issue or deny issuance of the authorization.

Summary of Request

    NMFS received an application on March 1, 2012, from ION for the 
taking, by harassment, of marine mammals incidental to a marine seismic 
survey in ice in the Beaufort and Chukchi Seas, Alaska, during October 
through December 15, 2012. After addressing comments from NMFS, ION 
modified its application and submitted a revised application on June 
11, 2012.

Description of the Specified Activity

    ION's activities consist of a geophysical in-ice (seismic 
reflection/refraction) survey and related vessel operations to be 
conducted primarily in the Alaskan Beaufort and Chukchi seas from 
October to December 15, 2012. The primary survey area extends from the 
U.S.-Canadian border in the east to Point Barrow in the west. Two 
survey lines extend west of Point Barrow into the northern Chukchi Sea, 
and three short tracks are proposed near the U.S.-Russian border (see 
Figure 1 of ION's IHA application). The bathymetry of the proposed 
survey area ranges from shallow (<20 m [66 ft]) to relatively deep 
(>3,500 m [11,483 ft]) water over the continental shelf, the 
continental slope, and the abyssal plain.
    The survey will be conducted from the seismic vessel Geo Arctic 
escorted by the Polar Prince, a medium class (100A) icebreaker. The 
survey grid consists of ~7,175 km (4,458 mi) of transect line, not 
including transits when the airguns are not operating. There may be 
small amounts of additional seismic operations associated with airgun 
testing, start up, and repeat coverage of any areas where initial data 
quality is sub-standard. The seismic source towed by the Geo Arctic 
would be an airgun array consisting of 26 active Sercel G-gun airguns 
with a total volume of 4,450 in\3\. A single hydrophone streamer 4.5-9 
km (2.8-5.6 mi) in length, depending on ice conditions, would be towed 
by the Geo Arctic to record the returning seismic signals.
    The survey vessels arrived in the survey area from Canadian waters 
in early October and plan to begin data collection on or after October 
15, 2012. After completion of the survey, or when ice and weather 
conditions dictate, the vessels will exit to the south, transiting 
through the Chukchi and Bering Seas. The Polar Prince may be used to 
perform an at-sea refueling (bunkering) operation to supply as much as 
500 metric tons of Arctic diesel to the Geo Arctic. The Polar Prince 
will carry that fuel onboard at the start of the operation, and it will 
be transferred to the Geo Arctic if/when necessary. Depending on its 
own fuel consumption, the Polar Prince may then transit to Tuktoyuktuk, 
Canada to take on additional fuel for itself. Once the Polar Prince 
returns to the Geo Arctic the survey would continue. The entire 
refueling operation will therefore involve one fuel transfer and 
potentially one transit to and from Tuktoyuktuk. The refueling 
operation will likely take place in late October, at which time the

[[Page 65061]]

Geo Arctic will likely be in the eastern or east-central Alaskan 
Beaufort Sea.
    ION's geophysical survey has been designed and scheduled to 
minimize potential effects to marine mammals, bowhead whales in 
particular, and subsistence users. For mitigation and operational 
reasons, the survey area has been bisected by a line that runs from 
70.5[deg] N. 150.5[deg] W. to 73[deg] N. 148[deg] W. (see Figure 1 of 
ION's IHA application). Weather and ice permitting, ION plans to begin 
survey operations east of the line described above (eastern survey 
area) and in offshore waters (>1,000 m [3,281 ft]) where bowheads are 
expected to be least abundant in early October. This operational plan 
is based on the fact that only ~2% of bowhead whales observed by Bureau 
of Ocean Energy Management's (BOEM) aerial surveys from 1979-2007 
occurred in areas of water depth >1,000 m (3,281 ft) (MMS, 2010), and 
on average ~97% of bowheads have passed through the eastern U.S. 
Beaufort Sea by October 15 (Miller et al., 2002). The survey will then 
progress to shallower waters in the eastern survey area before moving 
to the western survey area in late October or early November 2012.
    Ice conditions are expected to range from open water to 10/10 ice 
cover. However, the survey cannot take place in thick multi-year ice as 
both the icebreaker and seismic vessel must make continuous forward 
progress at 3-4 kts. In order for the survey to proceed, areas of high 
ice concentration can only consist of mostly newly forming juvenile 
first year ice or young first year ice less than 0.5 m (1.6 ft) thick. 
Sounds generated by the icebreaker and seismic vessel moving through 
these relatively light ice conditions are expected to be far below the 
high sound levels often attributed to icebreaking. These high sound 
levels (>200 dB re 1 [mu]Pa [rms]) have been recorded from icebreakers 
during backing and ramming operations in very heavy ice conditions and 
are created by cavitation of the propellers as the vessel is slowed by 
the ice or reverses direction (Erbe and Farmer, 1998; Roth and Schmidt, 
2010).

Acoustic Sources

(1) Seismic Airgun Array
    The seismic source used during the project would be an airgun array 
consisting of 28 Sercel G-gun airguns, of which 26 would be active and 
have a total discharge volume of 4,450 in\3\. The 28 airguns would be 
distributed in two sub-arrays with 14 airguns per sub-array. Individual 
airgun sizes range from 70 to 380 in\3\. Airguns will be operated at 
2,000 psi. The seismic array and a single hydrophone streamer 4.5-9 km 
(2.8-5.6 mi) in length would be towed behind the Geo Arctic. Additional 
specifications of the airgun array are provided in Appendix B of ION's 
IHA application.
(2) Echo Sounders
    Both vessels will operate industry standard echo sounder/fathometer 
instruments for continuous measurements of water depth while underway. 
These instruments are used by all large vessels to provide routine 
water depth information to the vessel crew. Navigation echo sounders 
send a single, narrowly focused, high frequency acoustic signal 
directly downward to the sea floor. The sound energy reflected off the 
sea floor returns to the vessel where it is detected by the instrument, 
and the depth is calculated and displayed to the user. Source levels of 
navigational echo sounders of this type are typically in the 180-200 dB 
re 1 [mu]PA-m (Richardson et al. 1995a).
    The Geo Arctic will use one navigational echo sounder during the 
project. The downward facing single-beam Simrad EA600 operates at 
frequencies ranging from 38 to 200 kHz with an output power of 100-2000 
Watts. Pulse durations are between 0.064 and 4.096 milliseconds, and 
the pulse repetition frequency (PRF or ping rate) depends on the depth 
range. The highest PRF at shallow depths is about 40 pings per second. 
It can be used for water depths up to 4,000 m (13,123 ft) and provides 
up to 1 cm (0.4 in) resolution.
    The Polar Prince will use one echo sounder, an ELAC LAZ-72. The 
LAZ-72 has an operating frequency of 30 kHz. The ping rate depends on 
the water depth and the fastest rate, which occurs in shallow depths, 
is about 5 pings per second.

Dates, Duration, and Region of Activity

    The proposed geophysical survey would be conducted for ~76 days 
from approximately October 15 to December 15, 2012. Both the Geo Arctic 
and the Polar Prince entered the Alaskan Beaufort Sea from Canadian 
waters in early October. The survey area will be bounded approximately 
by 138[deg] to 169[deg] W. longitude and 70[deg] to 73[deg] N. latitude 
in water depths ranging from <20 to >3,500 m (66 to 11,483 ft) (see 
Figure 1 of ION's IHA application). For mitigation and operational 
reasons the survey area has been bisected by a line that runs from 
70.5[deg] N, 150.5[deg] W to 73[deg] N, 148[deg] W. Weather and ice 
permitting, ION plans to begin survey operations east of the line 
(eastern survey area) in offshore waters (>1,000 m [3,281 ft]) where 
bowheads are expected to be least abundant in early October. The survey 
will then progress to shallower waters in the eastern survey area 
before moving to the west survey area in late October or early 
November. The vessels will depart the region to the south via the 
Chukchi and Bering Seas and arrive in Dutch Harbor in mid- to late 
December.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to ION was published in 
the Federal Register on August 17, 2012 (77 FR 49922). That notice 
described, in detail, ION's proposed 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 comments from the following organizations: the Marine Mammal 
Commission (Commission), the North Slope Borough (NSB), Oceana, Ocean 
Conservation Research, Ocean Conservancy, PEW Environment Group (PEW), 
and a group joined by the Alaska Wilderness League, Audubon Alaska, 
Center for Biological Diversity, EarthJustice, Natural Resources 
Defense Council, Northern Alaska Environmental Center, Ocean 
Conservation Research, Pacific Environment, Sierra Club, and World 
Wildlife Fund (AWL et al.).
    Any comments specific to ION's 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.

General MMPA Issues and Impact Analyses

    Comment 1: The Commission recommends that NMFS continue to include 
proposed incidental harassment authorization language, including the 
total number of estimated takes by Level A and Level B harassment, at 
the end of Federal Register notices but ensure that the language is 
consistent with that referenced in the main body of the corresponding 
notice.
    Response: NMFS agrees with the Commission's recommendation and 
will, to the extent practicable, include proposed incidental harassment 
authorization language at the end of Federal Register notices. In 
addition, NMFS agrees that the language should be consistent with that 
referenced in the main body of the corresponding notice and will make 
every effort to ensure consistency. However, the total number of 
estimated takes by Level A and Level B harassment is presented in 
tables

[[Page 65062]]

within the subsection Estimated Takes by Harassment of the Federal 
Register notice, and it would be redundant to repeat this information 
within the proposed incidental harassment authorization language 
elsewhere in the same Federal Register notice.
    Comment 2: The Commission recommends that NMFS propose to issue 
regulations under section 101(a)(5)(A) of the MMPA and a letter of 
authorization, rather than an incidental harassment authorization, for 
any proposed activities expected to cause a permanent threshold shift 
(PTS).
    Response: The legal requirements and underlying analysis for the 
issuance of an IHA concerning take do not require the issuance of 
regulations and a letter of authorization in this particular case. In 
order to issue an authorization pursuant to Section 101(a)(5)(D) of the 
MMPA, NMFS must determine that the taking by harassment of small 
numbers of marine mammal species or stocks will have a negligible 
impact on affected species or stocks, and will not have an unmitigable 
adverse impact on the availability of affected species or stocks for 
taking for subsistence uses. If there were a potential for serious 
injury or mortality, NMFS could not issue an IHA. Instead, any 
incidental take authorization would need to be processed under Section 
101(a)(5)(A) of the MMPA.
    As described here and in previous FR notices, PTS is considered to 
be injury (Level A Harassment). However, an animal would need to stay 
very close to the sound source for an extended amount of time to incur 
a serious degree of PTS, which could increase the probability of 
mortality. In this case, it would be highly unlikely for this scenario 
to unfold given the nature of any anticipated acoustic exposures that 
could potentially result from a mobile marine mammal that is generally 
expected to avoid loud sounds swimming in the vicinity of an airgun 
array moving at 3-4 knots. Therefore, it is appropriate to issue an 
incidental take authorization under 101(a)(5)(D), as we have made the 
necessary findings (described elsewhere in this document) under that 
Section of the MMPA.
    Comment 3: The Ocean Conservancy, Ocean Conservation Research, 
Oceana, and AWL et al. state the proposed seismic survey would result 
in harassment takes of a large number of marine mammals, specifically 
250 bowhead whales, 4,300 beluga whales, and 60,000 ringed seals, all 
of which would be exposed to received levels above 160 dB (rms). Thus, 
the commenters assert that NMFS cannot satisfy MMPA's small number and 
negligible impact provisions.
    Response: NMFS disagrees with the commenters' assessment. First, as 
mentioned in the Federal Register notice for the proposed IHA (77 FR 
49922; August 17, 2012) and earlier in this document, the estimated 
takes of marine mammals are based on summer/fall marine mammal 
densities. With most marine mammals moving out of the proposed seismic 
area as winter approaches, the density would be lower and the actual 
numbers of takes would be far fewer than those calculated based on fall 
densities. As described in the Negligible Impact and Small Numbers 
Analysis and Determination section of this document, NMFS considers the 
number of authorized takes small.
    As discussed in detail in the Negligible Impact and Small Numbers 
Analysis and Determination section of this document, most of the takes 
from ION's proposed in-ice 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, butare expected to resume their normal activities 
and reoccupy the area as soon as the vessels move away. Additionally, 
since the proposed icebreaking seismic survey is planned outside the 
time when ice seals are giving birth and after approximately 97% of the 
bowhead population is expected to have moved through the area, no 
impacts on pups or calves are expected, and nor are there any orther 
areas of particular importance for reproduction or feeding that could 
be impacted. Therefore, any behavioral effects to ringed seals, 
bowheads, or other species are not expected to have significant impacts 
to individual fitness or the population. In addition, the mitigation 
and monitoring measures (described previously in this document) 
included in the IHA are expected to further reduce any potential 
disturbance to marine mammals. Last, a small number of takes in the 
form of PTS are being authorized, however, if incurred, they would be 
expected to be minor in degree (low intensity--a few dBs of loss at 
certain frequencies), and they are not expected because of a 
combination of mitigation and likely avoidance of high source levels. 
Mortality is neither authorized nor anticipated.
    Therefore, NMFS believes that the take, by harassment, from ION's 
in-ice seismic survey will have a negligible impacton the affected 
species or stocks.
    Comment 4: The Ocean Conservancy, Ocean Conservation Research, and 
AWL et al. claims that NMFS failed to consider cumulative impacts 
adequately. In addition, AWL et al. states that it is essential for 
NMFS to consider ION's proposed survey along with the impacts of 
Shell's exploratory drilling program in Beaufort and Chukchi Seas.
    Response: Section 101(a)(5)(D) of the MMPA requires NMFS to make a 
determination that the harassment incidental to a specified activity 
will have a negligible impact on the affected species or stocks of 
marine mammals, and will not result in an unmitigable adverse impact on 
the availability of marine mammals for taking for subsistence uses. 
Neither the MMPA nor NMFS' implementing regulations specify how to 
consider other activities and their impacts on the same populations. 
However, consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338, September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into the 
negligible impact analysis via their impacts on the environmental 
baseline (e.g., as reflected in the density/distribution and status of 
the species, population size and growth rate, and ambient noise).
    In addition, cumulative effects were addressed in the Environmental 
Assessment and biological opinion prepared for this action, both of 
which NMFS indicated would be completed prior to the issuance of an IHA 
(77 FR 49922; August 17, 2012). The Environmental Assessment's 
cumulative effects analysis included consideration of (among other 
things): BP Exploration (Alasks), Inc.'s (BPXA) ocean-bottom-cable 
seismic surveys in the Simpson Lagoon area of the Beaufort Sea; BPXA's 
proposed Northstar oil production activity in the Beaufort Sea; and 
Shell Offshore Inc.'s (Shell) proposed exploratory drilling activities 
in the Beaufort and Chukchi Seas, Arctic warming, subsistence hunting, 
and noise contribution from vessel traffic.
    These documents, as well as the Alaska Marine Stock Assessments and 
the most recent abundance estimates for the affected species, are part 
of NMFS' Administrative Record for this action, and provided the 
decision maker with information regarding other activities in the 
action area that affect marine mammals, an analysis of cumulative 
impacts, and other information relevant to the determination made under 
the MMPA.
    Comment 5: AWL et al. states that in determining whether to proceed 
with

[[Page 65063]]

ION's request, NMFS must also consider the extent of missing 
information as to both the environmental baseline in the Arctic and 
marine mammal responses to noise in general.
    Response: NMFS has been conducting such analyses in both aspects 
since 2010 when it first received ION's IHA application.
    Regarding the environmental baseline, as described in the Federal 
Register notice for the proposed IHA (77 FR 49922; August 17, 2012), 
where the marine mammal distribution and density data for fall and 
winter seasons in the Beaufort and Chukchi Seas were not available, 
NMFS used the summer and fall density data. This data is an appropriate 
proxy for this analysis because it is for the same species and because 
we assume it is an overestimate since animals are known to move out of 
the area in the winter (Allen and Angliss 2011).
    Separately, regarding marine mammal responses to noise in general 
and as described in the Potential Effects of the Specified Activity on 
Marine Mammals section of the proposed IHA, while there are not data 
indicating the responses of every species to every specific sound 
source type, we believe that the large body of available information 
across multiple species and sound types allows us to reasonably 
anticipate likely responses to the proposed seismic airgun and 
icebreaking and make the findings necessary for issuance of this IHA.

Density Calculation and Take Estimate

    Comment 6: PEW states that NMFS did not use the best available data 
for impact analysis, as most survey data NMFS were collected during the 
open water season that usually conclude by October.
    Response: NMFS does not agree with PEW's statement that we did not 
use the best available data for impact analysis. As it was discussed in 
the Federal Register notice for the proposed IHA (77 FR 49922; August 
17, 2012), the reason for using the fall marine mammal densities for 
take calculation is because the lack of marine mammal density data in 
the winter season. Nevertheless, the fall marine mammal density data 
NMFS and ION used are the best available data. In addition, during the 
initial impact analysis, NMFS Office of Protected Resources and ION 
consulted with NMFS National Marine Mammal Laboratory (NMML) to make 
sure that the marine mammal density data used for impact analysis are 
the best available data. Using marine mammal summer/fall density data 
results in over-estimates as the overwhelming majority marine mammals 
will have likely departed the Beaufort and Chukchi Seas by the start of 
winter (Mate et al. 2000; Miller et al. 2002; Frost et al. 2004; Suydam 
et al. 2005; Cameron and Boveng, 2009; Christie et al. 2010; Allen and 
Angliss 2011).
    Comment 7: AWL et al. states that using density is unsuited for 
determining bowhead take during the fall migration. AWL et al. further 
argues that the bowhead whales would pass through the Beaufort and 
Chukchi Sea in the fall during their migration within a migratory 
corridor. AWL et al. then points out that it was not clear NMFS has 
adequately considered the migration of beluga whales in the Beaufort 
Sea as well. AWL et al. predicts that when taking the bowhead migration 
into account could dramatically increase the estimate of harassed 
whales.
    Response: NMFS does not agree AWL et al.'s assessment. ION's in-ice 
seismic survey would only occur after the majority of bowhead and 
beluga whales have migrated out of the Beaufort Sea. In addition, as 
noted in the Federal Register notice for the proposed IHA (77 FR 49922; 
August 17, 2012), ION would start its seismic survey from the east and 
proceed westward, thereby overlapping with the fewest possible number 
of marine mammals later in the season. Therefore, using summer/fall 
marine mammal density to calculate takes in the Arctic when most 
animals have left the area is a reasonable and scientifically 
supportable approach, although, as stated it will result in an over-
estimate of takes.
    Comment 8: The Commission requests NMFS require ION to (1) consult 
with NMFS National Marine Mammal Laboratory (NMML) and other 
researchers and revise its expected density estimates for gray whales 
and bearded seals to reflect new information from passive acoustic 
recordings, and (2) include, as appropriate, an estimate of takes by 
Level A harassment for those species. Citing Stafford et al. (2007), 
Wang and Overland (2009), Shelden and Mocklin (2012), the Commission 
points out that acoustic data show that these species are present 
throughout the winter months. The NSB also expresses its concern that 
bowhead and gray whales may remain in the area much longer than 
previously thought. Oceana is also concerned that there could be Level 
A takes of bearded seals, though it recognizes that much of the bearded 
seal population will have already migrated into the Bering Sea.
    Response: NMFS' Office of Protected Resources and ION worked 
extensively with NMFS' NMML on density estimates for all marine mammals 
(gray whales and bearded seals included) that could occur in the 
proposed survey area. The approaches took into account the best 
available scientific data on the abundance of marine mammals (gray 
whales and bearded seals included) that could potentially occur through 
the winter season, as well as estimates erred on the overestimation. 
NMFS and ION conducted a thorough review of acoustic recordings data 
pertaining to overwintering marine mammals (e.g., Stafford et al. 2007; 
Roth 2008; MacIntyre and Stafford 2011; Shelden and Mocklin 2012). We 
concluded that although some marine mammals were detected in the 
Beaufort and Chukchi Seas during this time, none of the studies allowed 
us to identify specific density estimates. In addition, many studies 
show that marine mammal calling rates dropped significantly during the 
winter months (Roth 2008; MacIntyre and Stafford 2011), which is 
consistent with our prediction based on tagging research (Cameron and 
Boveng 2009; Harwood et al. 2012). The notion is also shared by Oceana 
as it stated in its comment that much of the population of bearded 
seals will have already migrated into the Bering Sea. These reviews 
support our initial analyses and the basis for marine mammal take 
estimates. Therefore, we do not believe it is necessary, nor is it 
feasible, to revise density estimates or to include gray whales and 
bearded seals in the Level A take estimates.
    Finally, we acknowledge that bowhead and gray whales may remain in 
the Beaufort and Chukchi Seas during the timeframe of ION's proposed 
survey. To account for this possibility, NMFS relied on summer/fall 
data to estimate potential abundance of these species, which resulted 
in an over-estimate of take.
    Comment 9: The Commission requests NMFS require ION to recalculate 
expected densities for bowhead whales based on (1) the corrected 
decrease in abundance of bowhead whales reported by Miller et al. 
(2002) for early and late October (i.e., 78 percent) and (2) any 
additional information from more recent surveys, including acoustical 
surveys, conducted by NMFS' NMML and other researchers to assess the 
distribution and relative abundance of bowhead whales in the survey 
area from October through December.
    Response: Through the process of analyzing the potential impacts of 
ION's in-ice seismic survey in the Beaufort and Chukchi Seas, NMFS' 
Office of Protected Resources and ION worked extensively with NMFS' 
NMML on marine mammal density estimates, including distribution and 
densities of

[[Page 65064]]

bowhead whales. The early October (October 1-15) bowhead abundance of 
0.55 bowheads/100 km and the late October (October 15-31) abundance of 
0.12 bowheads/100 km reported in Miller et al. (2002) were both 
calculated as overall averages across the four survey regions and all 
water depth strata. The reference density to which the 90% decrease 
from early October to late October adjustment was applied was based 
only on bowhead sightings in less than 200 m of water. Thus, data in 
table Appendix 9.1 in Miller et al. (2002), which excludes water depths 
>200 m, were used for the calculation. In that table, the mean number 
of bowheads/100 km seen from October 1-15 was 0.618 and the mean for 
October 16-31 was 0.089. This represents an 86% decrease from early to 
late October, which was rounded to 90%.
    If the percentage decrease were left unrounded the average density 
for water depths <200 m in the Eastern Beaufort Sea in Table 2 of the 
ION's IHA application would become 0.0132 bowheads/km\2\. Using this 
value the take calculations would be 282, instead of the 201 stated in 
the Federal Register notice for the proposed IHA (77 FR 49922; August 
17, 2012).
    NMFS and ION by focused on bowhead whale aerial surveys that were 
conducted in the spring of 2011 and 2012. We ultimately agreed that the 
aerial survey data being used for density calculations was the most 
appropriate and that any newer data (i.e. from 2011 surveys) was of no 
added value. More recent aerial survey data were not used for the 
direct calculation of densities in late October as there have been very 
few surveys conducted at that time of year in the eastern U.S. Beaufort 
in recent years. Although acoustic data can be useful in assessing 
distribution, and to a limited extent, relative abundance, however, as 
with acoustic data for other marine mammals, none of them provides a 
basis for density estimates.
    Comment 10: The Commission requests NMFS provide stronger assurance 
that the actual number of takes would be negligible by (1) estimating 
the expected number of takes plus some measure of uncertainty in that 
estimate, (2) using maximum estimated densities of the marine mammals 
in the survey area to estimate takes, or (3) using some comparable 
approach that accounts for uncertainty and provides a high level of 
assurance that the actual taking would, in fact, be negligible. In 
addition, the Commission requests NMFS require ION to account for all 
sources of uncertainty in its estimation approach, including animals 
that may be present but not observed. Oceana and the NSB also express 
their concerns regarding the uncertainty of the impacts to marine 
mammals from ION's in-ice seismic survey during the winter season.
    Response: NMFS believes that the analyses provided in the Federal 
Register notice for the proposed IHA (77 FR 49922; August 17, 2012) has 
already provided a well-founded assurance that the impacts from even 
the overestimated takes, which were based on summer-fall marine mammal 
density, would be negligible to marine mammal species and stocks in 
ION's in-ice seismic survey areas in the Beaufort and Chukchi Seas, and 
that the take would not have unmitigable impacts to subsistence use of 
these species and stocks. These analyses already took uncertainties of 
marine mammal winter distribution and densities into account and erred 
on the side of caution.
    The determination regarding whether the total taking would have a 
negligible impact on the species or stocks is based on the species-
specific average density, or based on allotted number from past chance 
occurrence, as described above and in the proposed Federal Register 
notice for the proposed IHA (77 FR 49922; August 17, 2012). More 
importantly, the negligible impact analysis is not simply an assessment 
of the number of takes, but rather includes consideration of the 
nature, context, and likely severity of the takes, as well as the 
anticipated effectiveness of the mitigation measures. As described 
later in this document, our analysis allowed us to determine that the 
total taking would have a negligible impact on the affected species.
    Regarding the requirement for ION to account for all sources of 
uncertainty in its estimation approach, including animals that may be 
present but not observed, NMFS believes that all population survey 
studies, as well as density estimates, take into account for marine 
mammals not observed during the survey.

Acoustic Impacts

    Comment 11: PEW states that NMFS needs to ensure that best science 
is used when considering permitting an IHA to authorize Level A 
harassment of marine mammals, since this is the first time Level A take 
is being proposed.
    Response: NMFS has relied on the best available scientific 
information to support the issuance of ION's authorization. In the case 
of authorizing Level A harassment, NMFS has estimated that no more than 
1 bowhead whale, 3 beluga whales, and 4 ringed seals could, although 
unlikely, experience minor permanent threshold shifts of hearing 
sensitivity (PTS). The available data and analyses, as described more 
fully in the proposed IHA, include extrapolation results of many 
studies on marine mammal noise-induced temporary threshold shifts of 
hearing sensitivities (TTS) (Kryter 1985; Richardson et al. 1995; 
Kastak et al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005; 
Nachtigall et al. 2003; 2004; Kastak et al. 2004; 2005; Southall et al. 
2007; Mooney et al. 2009a; 2009b; Finneran et al. 2010a; 2010b). An 
extensive review of TTS studies and experiments prompted NMFS to 
conclude that possibility of minor PTS in the form of slight upward 
shift of hearing threshold at certain frequency bands by a few 
individuals of marine mammals is extremely low, but not unlikely.
    Comment 12: Citing NMFS' 1995 Federal Register notice (60 FR 
28379), AWL et al. argues that since the proposed seismic survey has 
the potential to cause permanent hearing loss in marine mammals, the 
impact must constitute ``serious injury.'' Ocean Conservancy also 
states that PTS equals ``serious injury''. AWL et al. further states 
that marine mammals enter the 180/190 dB re 1 [micro]Pa exclusion zones 
have at least the potential to suffer serious injury, and thus AWL et 
al. assumes that at least 23 beluga whales, 6 bowhead whales, and 277 
ringed seals could potentially suffer serious injury as a result of the 
survey. Oceana also expresses its concern that serious injury could 
occur to marine mammals.
    Response: Our understanding of noise-induced impacts on marine 
mammals has evolved over the past two decades and we no longer believe, 
based on the best available data, that PTS equals ``serious injury.'' 
As described in detail in the Federal Register notice for the proposed 
IHA (77 FR 49922; August 17, 2012), the potential Level A takes would 
be limited to minor degrees of PTS by 1 bowhead whale, 3 beluga whales, 
and 4 ringed seals. This level of injury is different from ``serious 
injury,'' which is defined as ``any injury that will likely result in 
mortality'' (50 CFR 229.2).
    Noise-induced threshold shifts (TS, include PTS) are defined as 
increases in the threshold of audibility (i.e., the sound has to be 
louder to be detected) of the ear at a certain frequency or range of 
frequencies (ANSI 1995; Yost 2000). Several important factors relate to 
the magnitude of TS, such as level, duration, spectral content 
(frequency range), and temporal pattern (continuous, intermittent) of 
exposure (Yost 2000; Henderson et al. 2008). TS occurs in terms of 
frequency range

[[Page 65065]]

(hertz [Hz] or kHz), hearing threshold level (dB), or both frequency 
and hearing threshold level (CDC 2004).
    In addition, there are different degrees of PTS: Ranging from 
slight/mild to moderate and from severe to profound (Clark 1981). 
Profound PTS or the complete loss of the ability to hear in one or both 
ears is commonly referred to as deafness (CDC 2004; WHO 2006). High-
frequency PTS, presumably as a normal process of aging that occurs in 
humans and other terrestrial mammals, has also been demonstrated in 
captive cetaceans (Ridgway and Carder 1997; Yuen et al. 2005; Finneran 
et al. 2005a; Houser and Finneran 2006; Finneran et al. 2007a; Schlundt 
et al. 2011) and in stranded individuals (Mann et al. 2010).
    In terms of what is analyzed for the potential PTS (Level A 
harassment) in marine mammals as a result of ION's in-ice seismic 
survey, if it occurs, NMFS has determined that the levels would be 
slight/mild because research shows that most cetaceans (and 
particularly Arctic cetaceans) show relatively high levels of avoidance 
when received sound pulse levels exceed 160 dB re 1 [mu]Pa (rms) 
(review in Richardson et al. 1995; Southall et al. 2007), and it is 
uncommon to sight Arctic cetaceans within the 180 dB radius, especially 
for prolonged duration. Results from monitoring programs associated 
with seismic activities in the Arctic have shown significant responses 
by cetaceans at levels much lower than 180 dB. These results have been 
used by agencies to support monitoring requirements within distances 
where received levels fall below 160 dB and even 120 dB. Thus, very few 
animals would be exposed to sound levels of 180 dB re 1 [mu]Pa (rms) 
regardless of detectability by protected species observers. Avoidance 
varies among individuals and depends on their activities or reasons for 
being in the area, and occasionally a few individual Arctic cetaceans 
will tolerate sound levels above 160 dB. Tolerance of levels above 180 
dB is infrequent, regardless of the circumstances. Therefore, a 
calculation of the number of cetaceans potentially exposed to >180 dB 
that is based simply on density would be a gross overestimate of the 
actual numbers exposed to 180 dB. Such calculations would be misleading 
unless avoidance response behaviors were taken into account to estimate 
what fraction of those originally present within the soon-to-be 
ensonified to >180 dB zone (as estimated from density) would still be 
there by the time levels reach 180 dB.
    Comment 13: The Ocean Conservancy and AWL et al. state that NMFS' 
analysis underestimated the impact of stress and the effects of airguns 
on bowhead whales.
    Response: NMFS does not agree with the assessment. The Federal 
Register for the proposed IHA (77 FR 49922; August 17, 2012) provided 
an analysis of the potential stress response to marine mammals (bowhead 
included) that could result from ION's in-ice seismic survey. However, 
almost no information is available on sound-induced stress in marine 
mammals, or on its potential (alone or in combination with other 
stressors) to affect the long-term well-being or reproductive success 
of marine mammals (Fair and Becker 2000; Hildebrand 2005; Wright et al. 
2007a, 2007b). Nevertheless, extrapolation of information regarding 
stress responses in other species is applicable because the responses 
are highly consistent among all species in which they have been 
examined to date, especially considering that marine mammals will 
likely respond in a manner consistent with other species studied 
(Wright et al. 2007a). In the section discussing non-auditory effects, 
NMFS summarized that a range of issues may arise from an extended 
stress response from noise exposure, which include suppression of 
reproduction (physiologically and behaviorally), accelerated aging and 
sickness-like symptoms. Such long-term effects, if they occur, would be 
mainly associated with chronic noise exposure, which is characteristic 
of some seismic surveys and exposure situations (McCauley et al. 2000b; 
Nieukirk et al. 2009) but not of some others. As described in the 
Federal Register notice for the proposed IHA (77 FR 49922; August 17, 
2012), ION's in-ice seismic survey would be performed in a limited area 
for a short duration (a total 76 days). In addition, the source vessel 
would be in constant movement as it acquires seismic data and [would 
not overlap with individuals for a substantial period of time]. 
Therefore, we have concluded that marine mammals would not suffer from 
chronic and long-term, noise exposure.
    In addition, NMFS provided more detailed analyses on noise-induced 
stress in its EA for the issuance of an IHA to ION (NMFS 2012), which 
also included three specific studies concerning marine mammals (Thomas 
et al. 1990; Romano et al. 2004; Rolland et al. 2012). These studies 
point out that short-term noise exposure, such as those animals being 
tested for TTS, only induced stress-immune system change during intense 
noise exposure (Romano et al. 2004), while during playbacks of recorded 
drilling noise to four captive beluga whales showed no changes in blood 
levels of stress-related hormones (Thomas et al. 1990).
    Comment 14: Citing Lucke et al. (2009) TTS experiment on a harbor 
porpoise, the AWL et al. points out that a harbor porpoise experienced 
TTS when exposed to airgun noise at 164 dB, a significantly lower level 
than what NMFS predicts.
    Response: NMFS does not agree with AWL et al.'s assessment. AWL et 
al. erroneously interpreted the results of the TTS-induced sound 
exposure level (SEL) in Lucke et al. (2009) to be sound pressure level 
(SPL) that NMFS uses for the threshold of PTS. In their paper, Lucke et 
al. (2009) found a threshold shift (TS) of a harbor porpoise after 
exposing it to airgun noise with peak-to-peak (pk-pk) received SPL at 
200.2 dBpk-pk re 1 [mu]Pa, which according to the authors, 
corresponds to SEL of 164.5 dB re 1 [mu]Pa\2\s after integrating 
exposure. It is important to understand that SPL and SEL are two very 
different ways to express the relative sound intensity. NMFS currently 
uses root-mean-square (rms) of received SPL at 180 dB and 190 dB re 1 
[mu]Pa as the threshold above which PTS could occur for cetaceans and 
pinnipeds, respectively, and that TTS is thought to occur below these 
levels. However, TTS experiments so far have shown that in almost all 
cases TTS would occur at levels much higher than the 180 and 190 dB re 
1 [mu]Pa thresholds. It is difficult to determine the equivalent of rms 
SPL from the reported pk-pk SPL in Lucke et al. (2009) because the 
airgun noise is a broadband impulse. Although it is a standard practice 
to subtract 9 dB from pk-pk SPL of a sinusoidal signal to convert it to 
rms SPL, for boardband signal from seismic surveys, the difference 
could be as large as 16 dB (Harris et al. 2001; McCauley et al. 2000). 
If we applied the 16 dB difference and convert the pk-pk reported in 
Lucke et al. (2009), the rms SPL for harbor porpoise to experience TTS 
would be 184 dB re 1 [mu]Pa, and the received levels associated with 
PTS (Level A harassment) would be higher than that. This is still above 
NMFS 180 dBrms re 1 [mu]Pa threshold for injury.
    Nevertheless, NMFS recognizes that the TTS threshold of harbor 
porpoise is lower that other cetacean species (bottlenose dolphin and 
beluga whale) tested (e.g., Finneran et al. 2002), and is discussed in 
the Federal Register notice of the proposed IHA (77 FR 49922; August 
17, 2012), as well as the EA for the issuance of the IHA to ION (NMFS 
2012).
    Comment 15: Citing Kastak et al. (2008) and Jujawa and Liberman 
(2009), AWL et al. states that anthropogenic sound can induce PTS at 
lower levels

[[Page 65066]]

than anticipated. In addition, AWL states that new data indicate that 
mid-frequency cetaceans, such as bottlenose dolphins and beluga whales 
have greater sensitivity to sounds within their best hearing range than 
was supposed at the time Southall et al. (2007) was published.
    Response: NMFS agrees that PTS could occur at relatively lower 
levels, such as at levels normally would only cause TTS, if the animal 
experiences repeated exposures at very close distances to the sound 
source. These long term effects are well known in terrestrial mammals 
(Yost 2000; Henderson et al. 2008) and is acknowledged in the Federal 
Register notice for the proposed IHA (77 FR 49922; August 17, 2012) 
that repeated exposure to elevated noise that causes TTS could 
eventually result in PTS. However, as mentioned in detailed in the 
proposed IHA, ION's in-ice seismic survey would be performed in a 
limited area for a short duration of a total 76 days. In addition, the 
source vessel would be in constant movement as it acquires seismic data 
and any overlap between the vessel and affected species would be 
minimal and short-lived. Therefore, NMFS considers it highly unlikely 
many animals would be repeatedly exposed to received levels that would 
cause TTS.
    As far as the hearing sensitivity of mid-frequency cetaceans is 
concerned, it is well known that mid-frequency cetaceans have greater 
sensitivity to sounds within their best hearing ranges, which are 
typically between 10-100 kHz (Johnson 1967; Hall and Johnson 1972; 
White et al. 1978; Awbrey et al. 1988; Johnson et al. 1989; Ridgway et 
al. 2001). Further TTS research on a bottlenose dolphin exposed to pure 
tones suggests that mid-frequency cetacean tends to be more vulnerable 
(in terms of TTS occurrence) at their most sensitive hearing range 
(Finneran et al. 2010). However, the majority of acoustic energy from a 
seismic airgun, vessel and icebreaking noise is under 1 kHz (Richardson 
et al. 1995), which is expected to have less impact on the most 
sensitive hearing ranges of these cetaceans.
    Comment 16: AWL et al. argues that NMFS' justifications for the use 
of a correction factor of only counting 10% marine mammals being 
exposure to received levels at Level A would show no avoidance and thus 
subject to PTS and that exposure will only be brief are both flawed and 
unsupported by survey data and scientific evidence. Citing Arctic 
seismic survey monitoring and mitigation reports from previous years, 
AWL et al. states that marine mammals, especially ice seals, do not 
always avoid loud noises, and that marine mammals routinely stray too 
close to the airguns, even during daylight hours. The Commission also 
requests NMFS require ION provide a scientific basis for any 
conclusions about the animals' responses to the airguns. The Commission 
further requests NMFS require ION to revise the estimated number of 
Level A harassment takes to include all marine mammals that may be 
exposed to source levels greater than or equal to 180 and 190 dB re 1 
[mu]Pa for cetaceans and pinnipeds, respectively.
    Response: NMFS does not agree with AWL et al.'s assessment. As 
discussed earlier in the response to Comment 13, NMFS' current Level A 
take threshold of 180 dB re 1 [mu]Pa for cetaceans is appropriate. 
Marine mammals found in these zones are not expected to experience TTS 
(a form of Level B Harassment), much less PTS (Level A Harassment) even 
if they are exposed to a few seismic impulses. On the other hand, 
almost all marine mammals that underwent TTS experiments showed strong 
aversive behavioral reactions when the received noise levels approached 
to levels that could cause TTS (e.g., Nachtigall et al. 2004; Fineran 
and Schlundt 2004; Lucke et al. 2009), despite the fact that these 
animals are trained and food-reinforced to participate the studies. 
Simply because previous seismic survey monitoring reports reveal that 
marine mammals were observed in the exclusion zones does not mean the 
animals necessarily experienced TTS, much less PTS..
    The 10% correction factor used by NMFS is appropriate for 
estimating likely Level A Harassment takes, since there is evidence 
suggesting that most, if not all, marine mammals would avoid the noise 
levels that could cause immediate PTS (as described in the Estimated 
Take section below.
    NMFS does not agree with the Commission's recommendation. Again, 
there is a difference between potential TTS (Level B Harassment), 
potential PTS (Level A Harassment) and serious injury. As described in 
detail in the response to Comment 13, the 180/190 dB re 1 [mu]Pa are 
the current standards used to prevent marine mammals from experiencing 
injury, which is equated with PTS, not TTS, which occurs at 
substantively lower received levels than PTS. In fact, all studies on 
marine mammal TTS have pointed out that TTS occurs at a received levels 
higher than NMFS current 180/190 dB re 1 [mu]Pa threshold (e.g., 
Finneran et al. 2000; 2002; Lucke et al. 2009). Even if the animal is 
exposed multiple times at levels higher than the 180/190 dB re 1 [mu]Pa 
threshold and receives TTS, it is not considered physical injury. TTS, 
which is also referred to as auditory fatigue, is a reversible hearing 
threshold shift and it often recovers within minutes to hours (Ward 
1997; Finneran et al. 2000; 2002). The numbers AWL et al. cited in 
their comment are the estimates of marine mammals that could occur 
within NMFS 180/190 dB re 1 [mu]Pa exclusion zones, which do not 
represent the number of animals that would receive TTS, not to mention 
PTS. In fact, NMFS considers in most cases all animals would avoid 
staying within the zones long enough to receive TTS. Therefore, most 
marine mammals will not experience TTS, which means the occurrence of 
PTS would be even lower.
    Finally, even if the animal receives PTS, this does not equate to 
serious injury. As stated earlier in response to Comment 13, NMFS 
defines injury as ``any injury that will likely result in mortality'' 
(50 CFR 229.2), which, based on the best available science and NMFS' 
judgment, does not include PTS. .
    Comment 17: The AWL et al. states that the current NMFS 160-dB re 1 
[mu]Pa threshold for Level B harassment is arbitrary and non-
conservative. Citing papers by Clark and Gagnon (2006), Risch et al. 
(2012), Bain and Williams (2006), Miller et al. (1999; 2005), the AWL 
et al. argues that in many cases marine mammals respond to much lower 
noise levels.
    Response: NMFS does not agree with AWL et al.'s assessment, as the 
papers AWL cited do not necessarily indicate that the animals exposed 
under the certain received levels constitute a ``take'' as defined 
under the MMPA. Clark and Gagnon (2006) reported that fin whales 
(Balaenoptera physalus) in the northeast Pacific Ocean went silent for 
an extended period starting soon after the onset of a seismic survey in 
the area, and Risch et al. (2012) reported that humpback whale 
(Megaptera novaeangliae) song in the Stellwagen Bank National Marine 
Sanctuary was reduced, concurrent with transmissions of an Ocean 
Acoustic Waveguide Remote Sensing experiment that produced series of 
frequency modulated pulses approximately 200 km away in the Gulf of 
Maine. Although Miller et al. (1999) reported that bowhead whale 
deflection may occur about 35 km (21.7 mi) to the east of the seismic 
operations, no SPL measurement to that distance was provided, except 
noting that received levels at 30 km (18.6 mi) were about 107-126 dB re 
1 [mu]Pa rms, depending on propagation. In addition, Miller et al. 
(2005) and Bain and Williams (2006) observed that marine mammal 
densities were generally lower

[[Page 65067]]

during seismic surveys and were seen moving away from seismic sources, 
even in areas where received levels were far below 160 dB re 1 [mu]Pa. 
Nevertheless, Miller et al. (2005) noted that bowhead whales have been 
sighted within the ``safety radius'' without any observed behavioral 
responses.
    To address these observations, it is important to understand that 
the vocal behaviors shown by fin and humpback whales, as reported by 
Clark and Gagnon (2006) and Risch et al. (2012), are considered to be 
related to mating activities, which do not apply to bowhead whales and 
other marine mammal species in the Beaufort and Chukchi Seas during 
ION's in-ice seismic survey. Second, as stated in the past, NMFS does 
not believe that minor course corrections during a migration or 
temporarily moving away from seismic source, as observed by Miller et 
al. (1999; 2005) and Bain and Williams (2005) 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 [micro]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., a reaction 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).
    Based on the information and data summarized in Southall et al. 
(2007), and on information from various studies, NMFS believes that the 
onset for behavioral harassment is largely context dependent, and there 
are many studies showing marine mammals do not show behavioral 
responses when exposed to multiple pulses at received levels above 160 
dB re 1 [micro]Pa (e.g., Malme et al. 1983; Malme et al. 1984; 
Richardson et al. 1986; Akamatsu et al. 1993; Madsen and M[oslash]hl 
2000; Harris et al. 2001; Miller et al. 2005). Therefore, although 
using a uniform SPL of 160-dB for the onset of behavioral harassment 
for impulse noises may not capture all of the nuances of different 
marine mammal reactions to sound, it is an appropriate way to manage 
and regulate anthropogenic noise impacts on marine mammals. Therefore, 
unless and until an improved approach is developed and peer-reviewed, 
NMFS will continue to use the 160-dB threshold for determining the 
level of take of marine mammals by Level B harassment for impulse noise 
(such as from airguns).
    Comment 18: Citing the Expert Panel Review of Statoil and ION's 
2011 monitoring plans, the AWL et al. states that the noise from 
seismic airgun arrays as ``a mixed impulsive/continuous noise source'' 
and that ``NMFS should evaluate its impacts on that basis.''
    Response: NMFS does not agree with the AWL et al.'s statement. 
First, nowhere in the Expert Panel's report did it states that airgun 
sound is ``a mixed impulsive/continuous noise source''. It has been 
well understood that the source characteristics from a seismic airgun 
(or airgun array) are impulsive, with no continuous acoustic components 
(Richardson et al. 1995). What the Expert Panel stated in its report is 
that ``seismic airgun signals should not be treated as truly impulsive 
when received at ranges where sound propagation is known to remove the 
impulsive nature of these signals'', which means that the signals 
become ``stretched'' at very large distance due to reverberation and 
multipath propagation. Furthermore, the Expert Panel stated that 
``[o]ver very short ranges where potential hearing loss (temporary or 
permanent) can occur, airgun impulses retain their impulsive features 
and should be considered as impulses.''
    Although it has been known that at long distances an impulse 
acoustic signal will lose its pulse feature by stretching its duration 
due to multipath propagation, these signals (or noises) are still 
fundamentally different from other non-impulse noise sources such as 
those from vibratory pile driving, drilling, and dredging based on the 
following characteristics:
    First, the elongated pulse signals from the airgun array at far 
distances are caused by multipath propagation in a reverberant 
environment (Greene and Richardson 1988; Richardson et al. 1995; Madsen 
et al. 2002; Lurton 2002), which is different from other non-pulse 
signals at closer distances, which is composed of mostly direct sound. 
The reverberation part of the sound in the ocean behaves differently 
compared to the direct sound and early surface and bottom reflections 
from the perspective of the receiver. The direct sound and early 
reflections follow the inverse square law, with the addition of 
absorption effects in the case of early reflections, and so their 
amplitude varies with distance. However the reverberant part of the 
sound remains relatively constant up to a large distance with the 
position of the receiver. Therefore, as distance increases from the 
source, the component of reverberant sounds increases against the 
direct sound. In addition, the reverberant energy is less directional 
and is distributed more uniformly around the ambient environment of the 
animal. As shown in human psychoacoustics, these characteristics in a 
reverberant field provide distance cues to the listener as to how far 
away the source is located (Howard and Angus 2006). Therefore, at a 
distance where the airgun signals have been ``stretched'' to non-pulse, 
the receiving animals would be able to correctly perceive that these 
sounds are coming from far away, and would thus be less likely to be 
affected behaviorally as behavior responses are not solely dependent on 
received levels. Other factors such as distance to the source, movement 
of the source, source characteristics, and the receiver's (i.e., 
animal's) age, sex, motivation states, and prior experience, etc. 
probably play more significant roles in determining the responses of 
the animals that are

[[Page 65068]]

being exposed to lower levels of noises than solely the received sound 
level.
    Second, even though during horizontal propagation, the initial 
short pulse could be ``stretched'' from milliseconds when emitted to 
about 0.25-0.5 second long at a few kilometers in shallow water 
(Richardson et al. 1995), the noise duration is still very short when 
compared to those ``conventional'' non-pulse noise sources (vibratory 
pile driving, drilling, and dredging, etc.) for which NMFS applies a 
120 dB threshold for assessing behavioral harassment. The empirical 
measurements of a 3,000 in3 airgun array received signal 
characteristics showed that its pulse duration was stretched to 0.2 
second at approximately 1.3 km (0.8 mi), to 0.5 second at approximately 
10 km (6.2 mi), and to about 1.8 seconds at 80 km (50 mi) from the 
source (O'Neill et al. 2011). Based on the airgun array's firing rate 
of 0.1 Hz (1 shot every 10 seconds), the duty cycle was only 18% for 
the signal at 80 km (50 mi) (1.8 seconds on for every 10 seconds). 
Conversely, the ``conventional'' non-pulse noises from vibratory pile 
driving, drilling, and dredging typically last much longer (minutes to 
hours) with very brief (seconds for vibratory pile driving) intervals.
    Therefore, NMFS does not agree that it is appropriate to treat 
elongated airgun pulses at long distances as a ``conventional'' non-
pulse signal and apply the 120 dB behavioral response threshold to that 
received sound.
    Comment 19: Citing Madsen (2005), the AWL et al. states that ``the 
threshold's basis in the root mean square (``RMS'') of sound pressure, 
rather than in peak pressure, is non-conservative.'' The AWL et al. 
further claims that studies have criticized the use of RMS for seismic 
sound because of the degree to which pulsed sounds must be 
``stretched,'' resulting in significant potential underestimates of 
marine mammal take. The AWL et al. predicts that if NMFS would modify 
its threshold estimates to use the peak pressure level instead of RMS, 
the estimated number of marine mammal takes could be significantly 
higher than the number of takes NMFS intends to authorize in for this 
survey.
    Response: NMFS does not agree with the AWL et al.'s statement. 
First, there is no scientific basis that the use of root-mean-square 
(rms) for sound pressure is less conservative than using peak pressure 
(which includes zero-peak pressure and peak-peak pressure). All of 
these are valid terms to express acoustic pressure and other physical 
oscillations (e.g., alternating electrical current). NMFS chooses to 
use rms because it was first established to regulate underwater noise 
impacts to marine mammals and that rms uses the product mean of 
acoustic pressures, which provides a more consistent result when 
dealing with multiple impulses such as pile driving. For a sinusoidal 
signal, the relationship between rms level and peak pressure level is 
that the rms level of a given sinusoidal signal is always 3 dB lower 
than the zero-peak level, and 9 dB lower than the peak-peak level. 
Therefore, for example, if the peak levels would be used to set the 
threshold for marine mammal disturbance, it would be 163 dB re 1 
[micro]Pa (0-peak) or 169 dB re 1 [micro]Pa (peak-peak), instead of the 
current 160 dB re 1 [micro]Pa (rms).
    Second, it is not true that the use of rms for calculating the 
levels of seismic impulse, or any other acoustic impulse, the pulsed 
sound ``must be stretched''. The concern raised by Madsen (2005) was 
the perceived lack of a standardized window for calculating the rms 
levels during averaging. Citing a 2003 Federal Register notice (68 FR 
9991; March 3, 2003), Madsen (2005) stated ``[t]he rms measure 
critically relies upon choosing the size of averaging window for the 
squared pressures. Derivation of this window is not standardized, which 
can lead to 2-12 dB differences in rms sound pressure for the same wave 
form.'' However, NMFS actually uses a standard 90% energy window when 
performing rms calculation for impulse sounds.
    Comment 20: The Ocean Conservation Research is concerned that 
acoustic impacts on the habitat, especially other marine organisms were 
not analyzed. In addition, citing Roth et al. (2012), the Ocean 
Conservation Research points out that the overall ambient noise levels 
could increase by 8 dB as a result of the seismic survey.
    Response: NMFS does not agree with the Ocean Conservation 
Research's assessment. The Federal Register notice for the proposed IHA 
(77 FR 49922; August 17, 2012) provided an analysis on the potential 
impacts of marine mammal habitat. The acoustic impacts on other marine 
organisms in the context of their value in marine mammal habitat, 
including planktonic species, invertebrates, and fish species are 
further analyzed in detail in the Environmental Assessment for the 
issuance of the IHA. Regarding the Ocean Conservation Research's 
concern of the raising ambient noise due to seismic survey in the 
Arctic, NMFS agrees that such concerns are valid, as was reported by 
Roth et al. (2012) that the average ambient noise in the Chukchi and 
Beaufort Seas increased by 2-8 dB in September and early October in all 
years between 2006 and 2009. However, ION's in-ice seismic survey is 
short in duration, will be confined to a limited area, and will occur 
from mid- to late-October through December, outside the time period of 
concern. The overall impact to the Beaufort and Chukchi Sea ecosystem, 
including marine mammal habitat, is not expected to be significant.

Monitoring and Mitigation Issues

    Comment 21: PEW states that NMFS should exclude important habitat 
from the survey area and institute time- and place-based restriction 
before permitting activities. Especially, PEW requested NMFS consider 
excluding Hanna and Herald Shoals, the Barrow Canyon, and the Chukchi 
Sea ice lead system.
    Response: Although the Hanna Shoals are located in the U.S. EEZ, 
the majority of the Herald Shoals are located in the Russian EEZ. 
Nevertheless, both areas are outside ION's seismic survey area. 
Although Barrow Canyon, which is on the edge of the proposed in-ice 
seismic survey boundary, is considered as an important feeding area for 
bowhead whales primarily due to its high productivity, it is only 
important to marine mammals during the open water summer and early fall 
seasons, which ends in September (Suydam et al. 2005; Ashjian et al. 
2010; Moore et al. 2010). The Chukchi Sea ice lead system along the 
entire Alaskan coastline serves as an important corridor for migrating 
marine mammals such as bowhead whales, especially during the spring 
(Braham et al. 1980). PEW even acknowledged in its comments to NMFS on 
the draft Environmental Impact Statement (EIS) on the Effects of Oil 
and Gas Activities in the Arctic Ocean (NMFS 2012a) that the bowhead 
whale population ``travels along the Chukchi Sea coast during spring 
months, from March through June.'' In addition, it is well known that 
bowhead whale fall migration does not necessarily follow the lead 
system (Huntington and Quakenbush 2009; Quakenbush et al. 2010; Allen 
and Angliss 2011). Considering that ION's in-ice seismic survey is 
designed specifically to avoid encountering large numbers of marine 
mammals after the majority of the animals have migrated out of the 
Beaufort and Chukchi Seas, NMFS does not believe that time and area 
restrictions are scientifically supportable or would provide any 
meaningful benefit to marine mammals.
    Comment 22: AWL et al. claims that NMFS did not fully consider the 
impacts of ION's survey on migrating bowhead whale mother and calf 
pairs,

[[Page 65069]]

as cows and calves are known to favor the tail end of the spring and 
fall migrations. Citing NMFS 2008 and 2011 Biological Opinions, AWL et 
al. states that females with young bowhead whales are more responsive 
to noise and human disturbance than other and that cow/calf pairs 
typically migrate through the area later in the season (i.e., late 
September/October). AWL et al. points out that in 2006 NMFS required a 
120-dB exclusion zone for four or more cow-calf pairs to reduce impacts 
on mother-calf pairs. In addition, the Commission also recommends NMFS 
require ION to establish and monitor adequately both a 160- and 120-dB 
re 1 [micro]Pa disturbance zone around all sound sources and to not 
initiate or continue an activity if (1) an aggregation of bowhead 
whales or gray whales (12 or more whales of any age/sex class that 
appear to be engaged in a non-migratory, significant biological 
behavior (e.g., feeding, socializing)) is observed within the 160-dB re 
1 [micro]Pa, or (2) a female-calf pair is observed within the 120-dB re 
1 [micro]Pa zone.
    Response: NMFS recognizes that bowhead cow and calf pairs are more 
prone to human disturbance than other individuals, and that they 
normally follow the tail-end of the migration. However, as discussed in 
the Federal Register notice for the proposed IHA (77 FR 49922; August 
17, 2012), ION's in-ice seismic survey will occur in the very latter 
part of the bowhead whale season (beginning after mid-October) and we 
expect very few exposures. Research indicates that on average about 97% 
of the bowhead whales would have passed through eastern of the Beaufort 
Sea by October 15 (Miller et al. 2002), and that all studies point that 
majority of the bowhead whales will be out of the Beaufort and Chukchi 
Seas (Allen and Angliss 2011). More importantly, ION plans to conduct 
its survey in an east to west fashion (the fall migration of bowhead 
whales occurs in an east to west direction), which would further reduce 
the potential takes of the few remaining whales. In addition, as 
discussed in the Federal Register notice for the proposed IHA (77 FR 
49922; August 17, 2012) and in the Environmental Assessment, daylight 
hours during ION's in-ice seismic survey would be very limited, which 
makes aerial surveys unfeasible. Therefore, based on our knowledge of 
bowhead whale migration and the practicability in carry out the 
monitoring and mitigation measures, NMFS will not require ION implement 
the 120-dB exclusion zone for cow-calf pairs nor the 160-dB exclusion 
zone for an aggregation of 12 or more whales, and concludes that the 
potential impacts to bowhead whale cow-calf pairs are extremely 
unlikely.
    Comment 23: AWL et al. states that NMFS should require ION provide 
additional clarification about the location and timing of its 
surveying. AWL et al. points out that the proposed IHA describes the 
surveying as beginning in deeper water (>1,000 m) in the eastern half 
of the survey area before moving to the west in late October or early 
November. AWL et al. states that bowhead migration has the potential to 
extend into late October and even November. AWL et al. further states 
that NMFS must specify the earliest date at which ION may survey in 
more shallow waters near the migration corridor, and include the 
specific timing of ION's operation in its conclusions and 
recommendations.
    Response: NMFS believes that ION's survey plan is adequately 
described in its application and the Federal Register notice for the 
proposed IHA (77 FR 49922; August 17, 2012). ION entered the U.S. 
Beaufort Sea survey area from Canadian waters in early October and 
plans to begin data collection in mid-October 2012. Therefore, the 
actual seismic survey would not start until after mid-October due to 
logistical delays. Weather and ice permitting, ION plans to begin 
survey operations east of the Beaufort Sea and in offshore waters 
(>1,000 m [3,281 ft]) where bowheads are expected to be least abundant 
in mid-October. This operational plan is based on the fact that only 
~2% of bowhead whales observed by Bureau of Ocean Energy Management's 
(BOEM) aerial surveys from 1979-2007 occurred in areas of water depth 
>1,000 m (3,281 ft) (MMS 2010), and on average ~97% of bowheads have 
passed through the eastern U.S. Beaufort Sea by October 15 (Miller et 
al. 2002). The survey would then progress to shallower waters in the 
eastern survey area before moving to the western survey area in late 
October or early November 2012. NMFS has conducted thorough analysis on 
potential disturbances of bowhead whales and other marine mammals in 
the entire Beaufort and Chukchi Seas for the period of ION's in-ice 
seismic survey and reached a negligible determination. Finally, at this 
point it is clear that the delay of ION's in-ice seismic survey into 
mid- to late October would further reduce impacts to marine mammals in 
the action area.
    Comment 24: The Commission requests that NMFS require ION to (1) 
record, analyze, and report (within five days of collecting the data) 
the results of measurements of vessel sounds, including the icebreaking 
vessel and (2) adjust the size of the 120-dB re 1 [micro]Pa harassment 
zone and revise the estimated number of animals expected to be taken by 
Level B harassment for all icebreaking activities, as necessary.
    Response: NMFS worked with ION on its sound source verification 
(SSV) measures when it first submitted its IHA application in 2010 and 
has continued to do so for the 2012 application. Due to the unique 
situation of the in-ice seismic survey, the traditional method of SSV 
test using bottom mounted hydrophone would not work. NMFS and ION have 
agreed to use the SSV measurements that ION collected in the ice-free 
Canadian Beaufort Sea, coupling with the in-situ sound velocity profile 
measurements in the seismic survey areas in the Beaufort and Chukchi 
Seas, to model the exclusion zones (180 and 190 dB re 1 [micro]Pa for 
cetaceans and pinnipeds, respectively) and behavioral harassment zones 
(160 and 120 dB re 1 [micro]Pa for seismic airgun array and icebreaking 
activity, respectively). However, after NMFS published its proposed 
IHA, ION informed NMFS that direct SSV measurements of airgun would be 
possible in the U.S. Beaufort Sea based on ice condition prediction. 
Therefore, ION will be conducting traditional SSV tests on its airgun 
array prior to conducting seismic surveys and submit the results within 
five days of collecting the data. ION will also adjust the size of the 
take zones based on the SSV tests. Nevertheless, NMFS does not believe 
direct SSV test in open water would be a good indicator for measuring 
icebreaking noise, since this would be an underestimate of noise 
produced during actual icebreaking activities. Therefore, for 
icebreaking activities, ION would use its seismic survey streamer to 
measure its noise during actual icebreaking, which is described in the 
Federal Register notice for the proposed IHA (77 FR 49922; August 17, 
2012). In addition, overwintering buoys deployed by ION and its partner 
would also provide better estimates of noise levels from icebreaking 
activities. However, these are no SSV measurements as these 
measurements could not be carried out under controlled test setting. 
Nevertheless, NMFS believes that the 160-dB re 1 [micro]Pa harassment 
zone from the seismic airgun array would surpass the 120-dB re 1 
[micro]Pa harassment zone from icebreaking activity based on acoustic 
modeling. Therefore, the 160-dB re 1 [micro]Pa received level from the 
airgun array would determine the numbers of marine mammals being taken.
    Comment 25: The NSB is concerned that ION's in-ice seismic survey 
would

[[Page 65070]]

be conducted during the time when visibility would be poor most of the 
time. The Commission and NSB request that NMFS require ION to use 
active acoustic monitoring, whenever practicable, to supplement visual 
monitoring during the implementation of its mitigation measures for all 
activities that generate sound. The NSB further recommends ION deploy 
their own acoustic recorders and collect the acoustic data.
    Response: As noted, NMFS' analyses on the potential impacts on 
marine mammals likely overestimates the number of animals taken and our 
analysis of the nature, context, and severity of those takes allowed to 
conclude that the taking will have a negligible impact on affected 
species or stocks. Further, NMFS has concluded that acoustic monitoring 
for ION's in-ice seismic survey is not necessary or practicable. In the 
Environmental Assessment prepared by NMFS, NMFS considered requiring 
ION to employ a near real-time passive acoustic monitoring (PAM) and 
active acoustic monitoring (AAM) program. These measures would 
supplement visual observation that is already required for ION. 
However, we determined these technologies should not be utilized in 
this particular instance because (1) the technologies are still being 
developed and thus, the efficacy of these measures for ION's survey 
would be questionable; and (2) the use of PAM, in particular, would 
require an additional icebreaker to serve as a PAM platform. After 
consulting with ION, we determined that a second icebreaker would not 
be practicable from an operational and economic perspective and could 
also result in additional environmental impacts such as additional 
noise being introduced into the water and disturbed habitat by 
additional icebreaking activities. Although NMFS has required the use 
of PAM in past IHAs (e.g., Houser et al. 2008; McPherson et al. 2012) 
and it has shown to be able to detect marine mammals beyond visual 
observation, as explained previously, we do not believe PAM is an 
appropriate mitigation tool for ION's project.
    Nevertheless, NMFS requires ION to work with other oil and gas 
companies in the Arctic to deploy overwintering acoustic sensors to 
assess the impacts of its in-ice seismic survey and provide a baseline 
of the acoustic environment and marine mammal distribution during the 
winter season.
    Comment 26: The Commission requests that NMFS specify reduced 
vessel speeds of 9 knots or less when in transit and 5 knots or less 
when weather conditions or darkness reduce visibility.
    Response: NMFS does not agree with the Commission's recommendation 
of specifying vessel speeds of 9 knots or less when in transit and 5 
knots or less when weather conditions or darkness reduce visibility. As 
NMFS discussed with ION, stipulating vessel speed during transit would 
severely hamper its proposed seismic survey activity, and would not be 
practicable. In any event, ION has indicated that its seismic vessel 
and icebreaker would normally move at a speed of 9-12 knots during 
transit and 4-5 knots during seismic survey.

NEPA and Miscellaneous Issues

    Comment 27: Noting that NMFS is still working on the Arctic EIS, 
AWL et al. and Oceana state that NEPA regulations makes clear that 
agencies should not proceed with authorizations for individual projects 
like the ION proposal until an ongoing programmatic EIS is complete.
    Response: NMFS does not agree with AWL et al. and Oceana's 
statement. While the Final EIS is still being developed, NMFS conducted 
a thorough analysis of the affected environment and environmental 
consequences from ION's in-ice seismic survey in the Beaufort and 
Chukchi Seas in 2012 and prepared an EA specific to the seismic survey 
program proposed to be conducted by ION. The analysis contained in that 
EA warranted a finding of no significant impact.
    The analysis contained in the Final EIS will apply more broadly to 
multiple Arctic oil and gas operations over an extended period. NMFS' 
issuance of the IHA to ION for the taking of several species of marine 
mammals incidental to conducting its in-ice seismic survey in the 
Beaufort and Chukchi Seas in 2012, as analyzed in the EA, is not 
expected to significantly affect the quality of the human environment. 
Additionally, the EA contained a full analysis of cumulative impacts.
    Comment 28: PEW states that traditional knowledge needs to be 
better incorporated into NMFS' analyses.
    Response: NMFS agrees that traditional knowledge (TK) is generally 
useful in understanding the potential environmental and subsistence 
impacts from activities such as ION's in-ice seismic survey. In fact, 
TK has been an important factor during NMFS analyses and review process 
of ION's in-ice seismic survey project, especially for the 
environmental analysis under the National Environmental Policy Act 
(NMFS 2012b). For instance, part of the analysis on bowhead whale 
westbound migration that does not depend on the Chukchi Sea ice lead 
system is from TK as described in Huntington and Quakenbush (2009).

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 two cetacean species, beluga 
(Delphinapterus leucas) and bowhead whales (Balaena mysticetus), and 
two pinniped species, ringed (Phoca hispida) and bearded (Erignathus 
barbatus) seals
    Three additional cetacean species and two pinniped species: Harbor 
porpoise (Phocoena phocoena), gray whale (Eschrichtius robustus), and 
minke whale (Balaenoptera acutorostrata); and spotted (P. largha) and 
ribbon seals (Histriophoca fasciata) could also occur in the project 
area.
    The bowhead whale is listed as ``endangered'' 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 listed as 
endangered or proposed for listing under the ESA; however, none of 
those stocks or populations occur in the proposed activity area. The 
ESA-listed western North Pacific gray whale population occurs in the 
West Pacific, and the ESA-listed Cook Inlet beluga population resides 
in Cook Inlet, Alaska. The southern distinct population segment of 
spotted seal that is listed under the ESA is found in Liaodong Bay, 
China, and Peter the Great Bay, Russia. Additionally, the ribbon seal 
is considered a ``species of concern'', meaning that NMFS has some 
concerns regarding status and threats to this species, but for which 
insufficient information is available to indicate a need to list the 
species under the ESA. Bearded and ringed seals are ``candidate 
species'' under the ESA, meaning they are currently being considered 
for listing.
    ION's application contains information on the status, distribution, 
seasonal distribution, and abundance of each of the species under NMFS' 
jurisdiction mentioned. 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 2011 SAR is 
available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2011.pdf.

[[Page 65071]]

Potential Effects of the Specified Activity on Marine Mammals

    Operating active acoustic sources such as airgun arrays and 
icebreaking activities have the potential for adverse effects on marine 
mammals.

Potential Effects of Airgun Sounds on Marine Mammals

    The effects of sounds from airgun pulses might include one or more 
of the following: Tolerance, masking of natural sounds, behavioral 
disturbance, and temporary or permanent hearing impairment or non-
auditory effects (Richardson et al. 1995). As outlined in previous NMFS 
documents, the effects of noise on marine mammals are highly variable. 
The Notice of Proposed IHA (77 FR 49922; August 17, 2012) included a 
discussion of the effects of airguns on marine mammals, which is not 
repeated here. That discussion did not take into consideration the 
monitoring and mitigation measures proposed by ION and those that will 
be required by NMFS. No instances of serious injury or mortality are 
expected as a result of ION's activities given the strong likelihood 
that marine mammals (especially migrating bowheads) would avoid the 
approaching airguns (or vessel) before being exposed to levels high 
enough for them to be seriously injured or killed.

Potential Effects From Icebreaking on Marine Mammals

    Icebreaking would be carried out for the ION's proposed in-ice 
seismic survey activities in the Beaufort and Chukchi Seas. Acoustic 
source modeling and propagation of the icebreaker were provided in the 
Notice of Proposed IHA (77 FR 49922; August 17, 2012). The source 
levels of the icebreaker are much lower than those of the airguns. 
Although they are non-impulse sounds and are treated differently from 
airgun pulses when the Level B behavioral harassment is considered, the 
120 dB re 1 [micro]Pa radii from icebreaking activities are still 
smaller than the 160 dB re 1 [micro]Pa radii. Therefore, the zone of 
influence from the airgun arrays essentially covers the area that would 
be ensonified by icebreaking activities during the survey, except for 
vessel transiting. The potential effects of icebreaking to marine 
mammals are discussed in the Federal Register notice for the proposed 
IHA (77 FR 49922; August 17, 2012) and are not repeated here.

Anticipated Effects on Habitat

    The primary potential impacts to marine mammals and other marine 
species are associated with elevated sound levels produced by airguns 
and other active acoustic sources, noise generated from icebreaking, 
and breaking of ice during the seismic survey. However, other potential 
impacts to the surrounding habitat from physical disturbance are also 
possible. Major potential anticipated effects on habitat from ION's 
proposed in-ice seismic survey include impacts on prey species (fish 
and other marine species that serve as marine mammal food) and physical 
environment (the destroy of ice layers) and are discussed in detail in 
the Federal Register notice for the proposed IHA (77 FR 49922; August 
17, 2012) and are not repeated here.

Potential Impacts on Availability of Affected Species or Stock for 
Taking for 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.''
    Seismic surveys and associated icebreaking operations have the 
potential to impact marine mammals hunted by Native Alaskans. In the 
case of cetaceans, the most common reaction to anthropogenic sounds (as 
noted previously in this document) is avoidance of the ensonified area. 
In the case of bowhead whales, this often means that the animals could 
divert from their normal migratory path by up to several kilometers. 
Additionally, general vessel presence in the vicinity of traditional 
hunting areas could negatively impact a hunt.
    In the case of subsistence hunts for bowhead whales in the Beaufort 
and Chukchi Seas, there could be an adverse impact on the hunt if the 
whales were deflected seaward (further from shore) in traditional 
hunting areas. The impact would be that whaling crews would have to 
travel greater distances to intercept westward migrating whales, 
thereby creating a safety hazard for whaling crews and/or limiting 
chances of successfully striking and landing bowheads. Native knowledge 
indicates that bowhead whales become increasingly ``skittish'' in the 
presence of seismic noise. Whales are more wary around the hunters and 
tend to expose a much smaller portion of their back when surfacing 
(which makes harvesting more difficult). Additionally, natives report 
that bowheads exhibit angry behaviors in the presence of seismic, such 
as tail-slapping, which translate to danger for nearby subsistence 
harvesters.
    However, due to its proposed time and location, ION's proposed in-
ice seismic survey in the Beaufort and Chukchi Seas would be unlikely 
to result in the aforementioned impacts. As discussed in detail in the 
Federal Register for the proposed IHA (77 FR 49922; August 17, 2012), 
the only potential impacts on subsistence use of marine mammals from 
ION's proposed icebreaking seismic survey during October--December 
period are the fall bowhead hunt and ringed seal harvest. Nevertheless, 
the proposed seismic survey is expected to occur in waters far offshore 
from the regular seal hunting areas, and ION indicates it would elect 
to operate at the eastern end of the survey area until fall whaling in 
the Beaufort Sea near Barrow is finished, thus reducing the likelihood 
of interfering with subsistence use of marine mammals in the vicinity 
of the project area.
    Finally, ION has signed a Conflict Avoidance Agreement (CAA), and 
prepared a Plan of Cooperation (POC) under 50 CFR 216.104 to address 
potential impacts on subsistence hunting activities. The CAA identifies 
those measures will be taken to minimize adverse impacts of the planned 
activities on subsistence harvesting. ION met with the AEWC and 
communities' Whaling Captains' Associations as part of the CAA 
development, and established avoidance guidelines and other mitigation 
measures to be followed where the activities may have an impact on 
subsistence.

Mitigation Measures

    Any incidental take authorization (ITA) under Section 101(a)(5)(D) 
of the MMPA, must prescribe where applicable, the permissible methods 
of taking pursuant to such activity, and other means of effecting the 
least practicable 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 ION's in-ice seismic survey in the Beaufort and Chukchi Seas, 
NMFS is requiring ION to implement the following mitigation measures to 
minimize the potential impacts to marine mammals in the project 
vicinity

[[Page 65072]]

as a result of the marine seismic survey activities.
    The mitigation measures are divided into the following major 
groups: (1) Establishing exclusion and disturbance zones, (2) Vessel 
speed or course alteration, (3) Ramp up procedures (4) Power down 
procedures, and (5) Shutdown procedures. 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) Exclusion Zones

    Under current NMFS guidelines, ``exclusion zones'' for marine 
mammals around industrial sound sources are customarily defined as the 
distances within which received sound levels are >=180 dB re 1 [mu]Pa 
(rms) for cetaceans and >=190 dB re 1 [mu]Pa (rms) for pinnipeds. These 
criteria are based on an assumption that sound energy at lower received 
levels will not injure these animals or impair their hearing abilities 
but that higher received 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 zone (Richardson et al., 1995).
    Received sound levels were modeled for the full 26 airgun, 4,450 
in\3\ array in relation to distance and direction from the source 
(Zykov et al., 2010). Based on the model results, Table 1 in this 
document shows the distances from the airguns where ION predicts that 
received sound levels will drop below 190, 180, and 160 dB re 1 [mu]Pa 
(rms). A single 70-in\3\ airgun would be used during turns or if a 
power down of the full array is necessary due to the presence of a 
marine mammal within or about to enter the applicable exclusion zone of 
the full airgun array. To model the source level of the 70-in\3\ 
airgun, ION used the measurements of a 30-in\3\ airgun. Underwater 
sound propagation of a 30-in\3\ airgun was measured in <100 m (328 ft) 
of water near Harrison Bay in 2007, and results were reported in Funk 
et al. (2008). The constant term of the resulting equation was 
increased by 2.45 dB based on the difference between the volume of the 
two airguns [2.45 = 20Log(70/30)-(\1/3\)]. The 190 and 180 dB (rms) 
distances for the 70-in\3\ airgun from the adjusted equation, 19 m (62 
ft) and 86 m (282 ft) respectively, would be used as the exclusion 
zones around the single 70 in\3\ airgun in all water depths until 
results from field measurements are available.
    An acoustics contractor would perform the direct measurements of 
the received levels of underwater sound versus distance and direction 
from the energy source arrays using calibrated hydrophones (see below 
``Sound Source Verification'' in the ``Monitoring and Reporting 
Measures'' section). The acoustic data would be analyzed as quickly and 
as reasonably practicable in the field and used to verify (and if 
necessary adjust) the size of the exclusion zones. The field report 
will be made available to NMFS and the Protected Species Observers 
(PSOs) within 120 hrs of completing the measurements. The mitigation 
measures to be implemented at the 190 and 180 dB (rms) sound levels 
would include power downs and shut downs as described below.

 Table 1--Marine Mammal Exclusion Zones From the 26 Airgun, 4,450-in\3\ Array, for Specific Categories Based on
                                                 the Water Depth
----------------------------------------------------------------------------------------------------------------
                                                                  Exclusion and disturbance zones (meters)
                                                           -----------------------------------------------------
                  rms  (dB re. 1 [mu]Pa)                     Depth less than    Depth 100 m-     Depth more than
                                                                  100 m            1,000 m           1,000 m
----------------------------------------------------------------------------------------------------------------
190.......................................................               600               180               180
180.......................................................             2,850               660               580
160.......................................................            27,800            42,200            31,600
----------------------------------------------------------------------------------------------------------------

(2) Speed or Course Alteration

    If a marine mammal (in water) is detected outside the exclusion 
zone and, based on its position and the relative motion, is likely to 
enter the exclusion zone, the vessel's speed and/or direct course shall 
be changed in a manner that also minimizes the effect on the planned 
objectives when such a maneuver is safe.
    Another measure proposes to avoid concentrations or groups of 
whales by all vessels in transit under the direction of ION. Operators 
of vessels should, at all times, conduct their activities at the 
maximum distance possible from such concentrations of whales.
    All vessels during transit shall be operated at speeds necessary to 
ensure no physical contact with whales occurs. If any barge or transit 
vessel approaches within 1.6 km (1 mi) of observed bowhead whales, the 
vessel operator shall take reasonable precautions to avoid potential 
interaction with the bowhead whales by taking one or more of the 
following actions, as appropriate:
    (A) Reducing vessel speed to less than 5 knots within 300 yards 
(900 feet or 274 m) of the whale(s);
    (B) Steering around the whale(s) if possible;
    (C) Operating the vessel(s) in such a way as to avoid separating 
members of a group of whales from other members of the group;
    (D) Operating the vessel(s) to avoid causing a whale to make 
multiple changes in direction; and
    (E) Checking the waters immediately adjacent to the vessel(s) to 
ensure that no whales will be injured when the propellers are engaged.
    When weather conditions require, such as when visibility drops, 
adjust vessel speed accordingly to avoid the likelihood of injury to 
whales.
    In the event that any aircraft (such as helicopters) are used to 
support the planned survey, the proposed mitigation measures below 
would apply:
    (A) Under no circumstances, other than an emergency, shall aircraft 
be operated at an altitude lower than 1,000 feet above sea level (ASL) 
when within 0.3 mile (0.5 km) of groups of whales.
    (B) Helicopters shall not hover or circle above or within 0.3 mile 
(0.5 km) of groups of whales.

(3) Ramp Ups

    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 is to ``warn'' marine mammals in the vicinity of the airguns 
and to provide the time for them to leave the area and thus avoid any 
potential injury or impairment of their hearing abilities.
    During the proposed seismic 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 or when no airguns have been

[[Page 65073]]

firing) will begin by firing a single airgun in the array. A full ramp 
up, following a cold start, can be applied if the exclusion zone has 
been free of marine mammals for a consecutive 30-minute period. The 
entire exclusion zone must have been visible during these 30 minutes. 
If the entire exclusion zone is not visible, then ramp up from a cold 
start cannot begin.
    Ramp up procedures from a cold start shall be delayed if a marine 
mammal is sighted within the exclusion zone during the 30-minute period 
prior to the ramp up. The delay shall last until the marine mammal(s) 
has been observed to leave the exclusion zone or until the animal(s) is 
not sighted for at least 15 or 30 minutes. The 15 minutes applies to 
small odontocetes and pinnipeds, while a 30 minute observation period 
applies to baleen whales and large toothed whales.
    A ramp up, following a shutdown, can be initiated if the marine 
mammal(s) for which the shutdown occurred has been observed to leave 
the exclusion zone or until the animal(s) is not sighted for at least 
15 minutes (small odontocetes and pinnipeds) or 30 minutes (baleen 
whales and large toothed whales).
    If, for any reason, electrical power to the airgun array has been 
discontinued for a period of 10 minutes or more, ramp-up procedures 
shall be implemented. Only if the PSO watch has been suspended, a 30-
minute clearance of the exclusion zone is required prior to commencing 
ramp-up. Discontinuation of airgun activity for less than 10 minutes 
does not require a ramp-up.
    The seismic operator and PSOs shall maintain records of the times 
when ramp-ups start and when the airgun arrays reach full power.
    During turns and transit between seismic transects, the 70 in\3\ 
mitigation gun will remain operational. The ramp up procedure will 
still be followed when increasing the source levels from one airgun to 
the full array. PSOs will be on duty whenever the airguns are firing 
during daylight and during the 30 minute periods prior to full ramp 
ups. Daylight will occur for ~11 hours/day at the start of the survey 
in mid-October diminishing to ~3 hours/day in mid-November.

(4) Power Down Procedures

    A power down involves decreasing the number of airguns in use such 
that the radii of the 190 and 180 dB re 1 [mu]Pa (rms) zones are 
decreased to the extent that observed marine mammals are not in the 
applicable exclusion zone. A power down may also occur when the vessel 
is moving from one seismic line to another. During a power down, only 
one airgun is operated. The continued operation of one airgun is 
intended to (a) alert marine mammals to the presence of the seismic 
vessel in the area, and (b) retain the option of initiating a ramp up 
to full array under poor visibility conditions. In contrast, a shutdown 
is when all airgun activity is suspended (see next section).
    If a marine mammal is detected outside the exclusion zone but is 
likely to enter the exclusion zone, and if the vessel's speed and/or 
course cannot be changed to avoid having the mammal enter the exclusion 
zone, the airguns may (as an alternative to a complete shutdown) be 
powered down before the mammal is within the exclusion zone. Likewise, 
if a mammal is already within the exclusion zone when first detected, 
the airguns will be powered down immediately if this is a reasonable 
alternative to a complete shutdown. During a power down of the array, 
the number of guns operating will be reduced to a single 70 in\3\ 
airgun. The pre-season estimates of the 190 dB re 1 [mu]Pa (rms) and 
180 dB re 1 [mu]Pa (rms) exclusion zones around the power down source 
are 19 m (62 ft) and 86 m (282 ft), respectively. The 70 in\3\ airgun 
power down source will be measured during acoustic sound source 
measurements conducted at the start of seismic operations. If a marine 
mammal is detected within or near the applicable exclusion zone around 
the single 70 in\3\ airgun, it too will be deactivated, resulting in a 
complete shutdown (see next subsection).
    Marine mammals hauled out on ice may enter the water when 
approached closely by a vessel. If a marine mammal on ice is detected 
by PSOs within the exclusion zones, it will be watched carefully in 
case it enters the water. In the event the animal does enter the water 
and is within an applicable exclusion zone of the airguns during 
seismic operations, a power down or shut-down will immediately be 
initiated. If the animal does not enter the water, it will not be 
exposed to sounds at received levels for which mitigation is required; 
therefore, no mitigation measures will be implemented.
    Following a power down, operation of the full airgun array will not 
resume until the marine mammal has cleared the exclusion zone. The 
animal will be considered to have cleared the exclusion zone if it:
     Is visually observed to have left the exclusion zone, or
     Has not been seen within the zone for 15 min in the case 
of pinnipeds (excluding walruses) or small odontocetes, or
     Has not been seen within the zone for 30 min in the case 
of mysticetes or large odontocetes.

(5) Shutdown Procedures

    The operating airgun(s) will be shut down completely if a marine 
mammal approaches or enters the then-applicable exclusion zone and a 
power down is not practical or adequate to reduce exposure to less than 
190 or 180 dB re 1 [mu]Pa (rms). The operating airgun(s) will also be 
shut down completely if a marine mammal approaches or enters the 
estimated exclusion zone around the reduced source (one 70 in\3\ 
airgun) that will be used during a power down.
    Airgun activity will not resume until the marine mammal has cleared 
the exclusion zone. The animal will be considered to have cleared the 
exclusion zone if it is visually observed to have left the exclusion 
zone, or if it has not been seen within the zone for 15 min (pinnipeds 
and small odontocetes) or 30 min (mysticetes and large odontocetes). 
Ramp up procedures will be followed during resumption of full seismic 
operations after a shutdown of the airgun array.
    In addition, a single airgun (also referred to as the ``mitigation 
gun'' in past IHAs) shall not be kept firing for long periods of time 
during darkness or other periods of poor visibility when seismic 
surveys are not ongoing, with the exception of turns when starting a 
new trackline, or short transits or maintenance with a duration of less 
than one hour.
    Finally, if a pinniped is sighted hauled out on ice within the 
underwater exclusion zone (received level 190 dB re 1 [mu]Pa (rms)), it 
will be watched carefully by the PSOs. Even though the pinniped may not 
be exposed to in-air noise levels that could be considered a take, the 
presence of the seismic vessel could prompt the animal to slip into the 
water, and thus be exposed to a high intensity sound field as a result. 
Therefore, the airgun should be powered down or shutdown immediately if 
thepinniped enters the water.
Mitigation Measures for Subsistence Activities
(1) Subsistence Mitigation Measures
    Since ION's proposed October--December in-ice seismic survey in the 
Beaufort and Chukchi Seas is unlikely to result in adverse impacts to 
subsistence users due to its proposed time and location, no specific 
mitigation measures are proposed other than those general mitigation 
measures discussed above.

[[Page 65074]]

(2) Plan of Cooperation (POC) and Conflict Avoidance Agreement (CAA)
    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 
activities that take place in Arctic waters to provide a 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.
    ION has signed a Conflict Avoidance Agreement (CAA) with the Alaska 
Eskimo Whaling Commission (AEWC) and communities' Whaling Captains' 
Associations for the proposed 2012 in-ice seismic survey. The main 
purpose of the CAA is to provide (1) equipment and procedures for 
communications between subsistence participants and industry 
participants; (2) avoidance guidelines and other mitigation measures to 
be followed by the industry participants working in or transiting in 
the vicinity of active subsistence hunters, in areas where subsistence 
hunters anticipate hunting, or in areas that are in sufficient 
proximity to areas expected to be used for subsistence hunting that the 
planned activities could potentially adversely affect the subsistence 
bowhead whale hunt through effects on bowhead whales; and (3) measures 
to be taken in the event of an emergency occurring during the term of 
the CAA.
    The CAA states that all vessels (operated by ION) shall report to 
the appropriate Communication Center (Com-Center) at least once every 
six hours commencing with a call at approximately 06:00 hours. The 
appropriate Com-Center shall be notified if there is any significant 
change in plans, such as an unannounced start-up of operations or 
significant deviations from announced course, and such Com-Center shall 
notify all whalers of such changes.
    The CAA further states that each Com-Center shall have an Inupiat 
operator (``Com-Center operator'') on duty 24 hours per day during the 
2012 subsistence bowhead whale hunt.
    In addition, ION has developed a ``Plan of Cooperation'' (POC) for 
the 2012 seismic survey in the Beaufort and Chukchi Seas in 
consultation with representatives of Barrow, Nuiqsut, Kaktovik, and 
Wainwright and subsistence users within these communities. NMFS 
received the final POC on August 13, 2012. The final POC is posted on 
NMFS Web site at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Mitigation Conclusions
    NMFS has carefully evaluated these 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;
     The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned; 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 and proposed by the 
independent peer review panel, NMFS has determined that the proposed 
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

    Any ITA issued under Section 101(a)(5)(D) of the MMPA is required 
to prescribe, where applicable, ``requirements pertaining to the 
monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) state 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.

(1) Protected Species Observers (PSOs)

    Vessel-based monitoring for marine mammals shall be performed by 
trained PSOs throughout the period of survey activities, supplemented 
by the officers on duty, to comply with expected provisions in the IHA. 
The observers shall monitor the occurrence and behavior of marine 
mammals near the survey vessels during all daylight periods. PSO duties 
include watching for and identifying marine mammals; recording their 
numbers, distances, and reactions to the survey operations; and 
documenting ``take by harassment'' as defined by NMFS.
A. Number of Observers
    A sufficient number of PSOs shall 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.
    An experienced field crew leader shall supervise the PSO team 
onboard the survey vessels. ION's proposed survey will occur in 
October-December when the number of hours of daylight is significantly 
reduced, and thus will require fewer PSOs to be aboard the survey 
vessel than required for surveys conducted during the open water season 
with nearly 24 hrs of daylight. PSOs aboard the icebreaker operating 
0.5-1 km (0.31-0.62 mi) ahead of the survey vessel will provide early 
detection of marine mammals along the survey track. Three PSOs will be 
stationed aboard the icebreaker Polar Prince to take advantage of this 
forward operating platform and provide advance notice of marine mammals 
to the PSO on the survey vessel. Three PSOs will be stationed aboard 
the survey vessel Geo Arctic to monitor the exclusion zones centered on 
the airguns and to request mitigation actions when necessary.
B. Observer Qualifications and Training
    Crew leaders and most other biologists serving as observers shall 
be individuals with recent experience as observers during one or more 
seismic monitoring projects in Alaska, the Canadian Beaufort Sea, or 
other offshore areas.
    Biologist-observers shall have previous marine mammal observation 
experience, and field crew leaders will be highly experienced with 
previous vessel-based marine mammal monitoring and mitigation projects. 
R[eacute]sum[eacute]s for all individuals shall be provided to NMFS for 
review and acceptance of their qualifications. Inupiat observers will 
be experienced in the region, familiar with the marine mammals of the 
area, and complete an approved observer training course designed to 
familiarize individuals with monitoring and data collection procedures. 
A PSO handbook, adapted for the specifics of the planned survey 
program, will be prepared and distributed beforehand to all PSOs.
    Biologist-observers and Inupiat observers shall also complete a two 
or three-day training and refresher session together on marine mammal 
monitoring, to be conducted shortly before the anticipated start of the 
seismic survey. When possible, experienced observers shall be paired 
with inexperienced observers. The training session(s) shall be 
conducted by qualified marine

[[Page 65075]]

mammalogists with extensive crew-leader experience during previous 
vessel-based seismic monitoring programs.
    Primary objectives of the training include:
     Review of the marine mammal monitoring plan for this 
project, including any amendments specified by NMFS in the IHA;
     Review of marine mammal sighting, identification, and 
distance estimation methods using visual aids;
     Review of operation of specialized equipment (reticle 
binoculars, night vision devices (NVDs), and GPS system);
     Review of, and classroom practice with, data recording and 
data entry systems, including procedures for recording data on marine 
mammal sightings, monitoring operations, environmental conditions, and 
entry error control. These procedures will be implemented through use 
of a customized computer database and laptop computers;
     Review of the specific tasks of the Inupiat Communicator; 
and
     Exam to ensure all observers can correctly identify marine 
mammals and record sightings.
C. PSO Handbook
    A PSOs' Handbook will be prepared for ION's monitoring program. 
Handbooks contain maps, illustrations, and photographs, as well as 
text, and are intended to provide guidance and reference information to 
trained individuals who will participate as PSOs. The following topics 
will be covered in the PSO Handbook for the ION project:
     Summary overview descriptions of the project, marine 
mammals and underwater noise, the marine mammal monitoring program 
(vessel-based, aerial, acoustic measurements), the NMFS' IHA (if 
issued) and other regulations/permits/agencies, the Marine Mammal 
Protection Act;
     Monitoring and mitigation objectives and procedures, 
initial exclusion zones;
     Responsibilities of staff and crew regarding the marine 
mammal monitoring plan;
     Instructions for ship crew regarding the marine mammal 
monitoring plan;
     Data recording procedures: codes and coding instructions, 
common coding mistakes, electronic database; navigational, marine 
physical, field data sheet;
     List of species that might be encountered: identification 
cues, natural history information;
     Use of specialized field equipment (reticle binoculars, 
NVDs, forward-looking infrared (FLIR) system);
     Reticle binocular distance scale;
     Table of wind speed, Beaufort wind force, and sea state 
codes;
     Data storage and backup procedures;
     Safety precautions while onboard;
     Crew and/or personnel discord; conflict resolution among 
PSOs and crew;
     Drug and alcohol policy and testing;
     Scheduling of cruises and watches;
     Communication availability and procedures;
     List of field gear that will be provided;
     Suggested list of personal items to pack;
     Suggested literature, or literature cited; and
     Copies of the NMFS IHA and USFWS LOA.

(2) Monitoring Methodology

A. General Monitoring Methodology
    The observer(s) will watch for marine mammals from the best 
available vantage point on the survey vessels, typically the bridge. 
The observer(s) will scan systematically with the unaided eye and 7 x 
50 reticle binoculars, supplemented during good visibility conditions 
with 20 x 60 image-stabilized Zeiss Binoculars or Fujinon 25 x 150 
``Big-eye'' binoculars, a thermal imaging (FLIR) camera, and night-
vision equipment when needed (see below). Personnel on the bridge shall 
assist the marine mammal observer(s) in watching for marine mammals.
    Information to be recorded by observers shall include the same 
types of information that were recorded during recent monitoring 
programs associated with Industry activity in the Arctic (e.g., Ireland 
et al., 2009). When a mammal sighting is made, the following 
information about the sighting shall be recorded:
     Species, group size, age/size/sex categories (if 
determinable), behavior when first sighted and after initial sighting, 
heading (if determinable), bearing and distance from observer, apparent 
reaction to activities (e.g., none, avoidance, approach, etc.), closest 
point of approach, and pace;
     Additional details for any unidentified marine mammal or 
unknown observed;
     Time, location, speed, and activity of the vessel, sea 
state, ice cover, visibility, and sun glare; and
     The positions of other vessel(s) in the vicinity of the 
observer location.
    The ship's position, speed of the vessel, water depth, sea state, 
ice cover, visibility, airgun status (ramp up, mitigation gun, or full 
array), and sun glare shall also be recorded at the start and end of 
each observation watch, every 30 minutes during a watch, and whenever 
there is a change in any of those variables.
    Distances to nearby marine mammals will be estimated with 
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. However, previous 
experience has shown that a Class 1 eye-safe device was not able to 
measure distances to seals more than about 70 m (230 ft) away. The 
device was very useful in improving the distance estimation abilities 
of the observers at distances up to about 600 m (1,968 ft), the maximum 
range at which the device could measure distances to highly reflective 
objects such as other vessels. Humans observing objects of more-or-less 
known size via a standard observation protocol, in this case from a 
standard height above water, quickly become able to estimate distances 
within about 20% when given immediate feedback about actual 
distances during training.
    When a marine mammal is seen within the exclusion zone applicable 
to that species, the geophysical crew shall be notified immediately so 
that mitigation measures required by the IHA (if issued) can be 
implemented. It is expected that the airgun array will be shut down 
within several seconds, often before the next shot would be fired, and 
almost always before more than one additional shot is fired. The 
protected species observer shall then maintain a watch to determine 
when the mammal(s) appear to be outside the exclusion zone such that 
airgun operations can resume.
    ION will provide or arrange for the following specialized field 
equipment for use by the onboard PSOs: 7 x 50 reticle binoculars, Big-
eye binoculars or high power image-stabilized binoculars, GPS unit, 
laptop computers, night vision binoculars, digital still and possibly 
digital video cameras in addition to the above mentioned FLIR camera 
system (see below).
B. Monitoring at Night and in Poor Visibility
    Night-vision equipment (Generation 3 binocular image intensifiers, 
or equivalent units) will be available for use when/if needed. Past 
experience with NVDs in the Beaufort Sea and elsewhere has indicated 
that NVDs are

[[Page 65076]]

not nearly as effective as visual observation during daylight hours 
(e.g., Harris et al., 1997, 1998; Moulton and Lawson, 2002). A FLIR 
camera system mounted on a high point near the bow of the icebreaker 
will also be available to assist with detecting the presence of seals 
and polar bears on ice and, perhaps also in the water, ahead of the 
airgun array. The FLIR system detects thermal contrasts and its ability 
to sense these differences is not dependent on daylight.
    Additional details regarding the monitoring protocol during NVD and 
FLIR system use has been developed in order to collect data in a 
standardized manner such that the effectiveness of the two devices can 
be analyzed and compared.
B. (1) FLIR and NVD Monitoring
    The infrared system is able to detect differences in the surface 
temperature of objects making it potentially useful during both 
daylight and darkness periods. NVDs, or light intensifiers, amplify low 
levels of ambient light from moonlight or sky glow light in order to 
provide an image to the user. Both technologies have the potential to 
improve monitoring and mitigation efforts in darkness. However, they 
remain relatively unproven in regards to their effectiveness under the 
conditions and it the manner of use planned for this survey. The 
protocols for FLIR and NVD use and data collection described below are 
intended to collect the necessary data in order to evaluate the ability 
of these technologies to aid in the detection of marine mammals from a 
vessel.
     All PSOs shall monitor for marine mammals according to the 
procedures outlined in the PSO handbook.
     One PSO shall be responsible for monitoring the FLIR 
system (IR-PSO) during most darkness and twilight periods. The on-duty 
IR-PSO shall monitor the IR display and alternate between the two 
search methods described below. If a second PSO is on watch, they shall 
scan the same area as the FLIR using the NVDs for comparison. The two 
PSOs shall coordinate what area is currently being scanned.
     The IR-PSO should rotate between the search methods (see 
below) every 30 minutes in the following routine:
[cir] 00:00-00:30: Method I
[cir] 00:30-01:00: Method II, Port side
[cir] 01:00-01:30: Method I
[cir] 01:30-02:00: Method II, Starboard side
B. (2) FLIR Search Methods
    The FLIR system consists of a camera that will be mounted on high 
point in front of the vessel. The camera is connected to a joystick 
control unit (JCU) and a display monitor that will be located on the 
bridge of the vessel. The IR-PSO shall manually control the view that 
is displayed by adjusting the pan (360[deg] continuous pan) and tilt 
(+/-90[deg] tilt) settings using the JCU. The FLIR manufacturer has 
indicated that they have tested the FLIR unit (model M626L) to -25 
[deg]C (-13[emsp14][deg]F), but expect that it will operate at colder 
temperatures. During the time of the proposed seismic survey, the 
average minimum temperatures at Prudhoe Bay in October and November are 
+10[emsp14][deg]F and -10[emsp14][deg]F, respectively. Colder 
temperatures are certainly likely at times, but overall the 
temperatures should generally be within the operational range of the 
equipment.
    As noted above, two different search methods shall be implemented 
for FLIR monitoring and results from the two will be compared. The 
first method involves a back-and-forth panning motion and the second 
utilizes the FLIR unit focused on a fixed swath ahead and to one side 
of the vessel track:
    Method I: Set the horizontal tilt of the camera to an angle that 
provides an adequate view out in front of the vessel and also provides 
good resolution to potential targets (this will likely mean that the 
lower portion of the view displayed on the monitor is of an area 
relatively close to the vessel (<100 m [328 ft]) while the middle and 
upper portions of the view are at greater distances (500-2,000 m 
[1,640-6,562 ft]). Pan back and forth across the forward 180[deg] of 
the vessels heading at a slow-scanning rate of approximately 1-2[deg]/
sec, as one would with binoculars. This method is intended to replicate 
the type of observations conducted using binoculars and cover a 
relatively wider swatch compared to Method II. It should produce 
sightings data that can be analyzed using line-transect methodologies 
to estimate marine mammal densities in the survey area.
    Method II: Set the horizontal tilt of the camera to an angle that 
provides an adequate view out in front of the vessel (similar or 
identical to the above), and then set the camera at a fixed position 
that creates a swath of view off the bow and to one side of the vessel 
(see Figure 1 of ION's monitoring plan). This method essentially 
establishes a fixed-strip width that is intended to produce sightings 
data that can be analyzed using strip-transect methodologies to 
estimate marine mammal densities.
B. (3) NVD Methods
    The NVDs are goggles worn by the observer and are to be used in a 
similar fashion as binoculars. When observing in conjunction with the 
FLIR system, the objective will be to replicate the monitoring 
methodology being employed by the FLIR system. Method I requires a full 
180[deg] scan (or as large of a range as possible from the observer's 
location) with the NVDs, and Method II requires a focused scan of the 
~60[deg] swath being monitored by the FLIR system.
C. Field Data-Recording, Verification, Handling, and Security
    The observers shall record their observations onto datasheets or 
directly into handheld computers. During periods between watches and 
periods when operations are suspended, those data shall be entered into 
a laptop computer running a custom computer database. The accuracy of 
the data entry shall be verified in the field by computerized validity 
checks as the data are entered, and by subsequent manual checking of 
the database printouts. These procedures will allow initial summaries 
of data to be prepared during and shortly after the field season, and 
shall facilitate transfer of the data to statistical, graphical or 
other programs for further processing. Quality control of the data will 
be facilitated by (1) the start-of-season training session, (2) 
subsequent supervision by the onboard field crew leader, and (3) 
ongoing data checks during the field season.
    The data shall be backed up regularly onto CDs and/or USB disks, 
and stored at separate locations on the vessel. If possible, data 
sheets will be photocopied daily during the field season. Data shall be 
secured further by having data sheets and backup data CDs carried back 
to the Anchorage office during crew rotations.
    In addition to routine PSO duties, observers shall use Traditional 
Knowledge and Natural History datasheets to record observations that 
are not captured by the sighting or effort data. Copies of these 
records will be available to observers for reference if they wish to 
prepare a statement about their observations. If prepared, this 
statement would be included in the 90-day and final reports documenting 
the monitoring work.
D. Effort and Sightings Data Collection Methods
    Observation effort data shall be designed to capture the amount of 
PSO effort itself, environmental conditions

[[Page 65077]]

that impact an observer's ability to detect marine mammals, and the 
equipment and method of monitoring being employed. These data shall be 
collected every 30 minutes or when an effort variable changes (e.g., 
change in the equipment or method being used to monitor, on/off-signing 
PSO, etc.), and shall be linked to sightings data. Effort and sightings 
data forms are the same forms used during other marine mammal 
monitoring in the open water season, but additional fields have been 
included to capture information specific to monitoring in darkness and 
to more accurately describe the observation conditions. The additional 
fields include the following.
     Observation Method: FLIR, NVD, spotlight, eye (naked eye 
or regular binoculars), or multiple methods. This data is collected 
every 30 minutes with the Observer Effort form and with every sighting.
     Cloud Cover: Percentage. This can impact lighting 
conditions and reflectivity.
     Precipitation Type: Fog, rain, snow, or none.
     Precipitation Reduced Visibility: Confirms whether or not 
visibility is reduced due to precipitation. This will be compared to 
the visibility distance ( km) to determine when visibility is 
reduced due to lighting conditions versus precipitation.
     Daylight Amount: Daylight, twilight, dark. The addition of 
the twilight field has been included to record observation periods 
where the sun has set and observation distances may be reduced due to 
lack of light.
     Light Intensity: Recorded in footcandles (fc) using an 
incident light meter. This procedure was added to quantify the 
available light during twilight and darkness periods and may allow for 
light-intensity bins to be used during analysis.
    Analysis of the sightings data shall include comparisons of 
nighttime (FLIR and NVD) sighting rates to daylight sighting rates. 
FLIR and NVD analysis will be independent of each other and according 
to method (I or II) used. Comparison of NVD and FLIR sighting rates 
will allow for a comparison of marine mammal detection ability of the 
two methods. However, results and analyses could be limited if 
relatively few sightings are recorded during the survey.

(3) Acoustic Monitoring Plan

A. Sound Source Measurements
    As described above, received sound levels were modeled for the full 
26 airgun, 4,450 in\3\ array in relation to distance and direction from 
the source (Zykov et al., 2010). These modeled distances will be used 
as temporary exclusion zones until measurements of the airgun sound 
source are conducted. The measurements shall be made at the beginning 
of the field season, and the measured radii shall be used for the 
remainder of the survey period. An acoustics contractor with experience 
in the Arctic conducting similar measurements in recent years will use 
their equipment to record and analyze the underwater sounds and write 
the summary reports as described below.
    The objectives of the sound source measurements planned for 2012 in 
the Beaufort Sea will be (1) to measure the distances in potentially 
ice covered waters in the broadside and endfire directions at which 
broadband received levels reach 190, 180, 170, 160, and 120 dB re 1 
[mu]Pa (rms) for the energy source array combinations that may be used 
during the survey activities, and (2) measure the sounds produced by 
the icebreaker and seismic vessel as they travel through sea ice. 
Conducting the sound source and vessel measurements in ice-covered 
waters using bottom founded recorders creates a risk of not being able 
to retrieve the recorders and analyze the data until the following 
year. If the acoustic recorders are not deployed or are unable to be 
recovered because of too much sea ice, ION shall use measurements of 
the same airgun source taken in the Canadian Beaufort Sea in 2010, 
along with sound velocity measurements taken in the Alaskan Beaufort 
Sea at the start of the 2012 survey to update the propagation model and 
estimate new exclusion zones. These modeled results shall then be used 
for mitigation purposes during the remainder of the survey.
    The airgun configurations measured shall include at least the full 
26 airgun array and the single 70 in\3\ mitigation airgun that will be 
used during power downs. The measurements of airgun array sounds will 
be made by an acoustics contractor at the beginning of the survey and 
the distances to the various radii will be reported as soon as possible 
after recovery of the equipment. The primary area of concern will be 
the 190 and 180 dB re 1 [mu]Pa (rms) exclusion zones for pinnipeds and 
cetaceans, respectively, and the 160 dB re 1 [mu]Pa Level B harassment 
(for impulsive sources) radii. In addition to reporting the radii of 
specific regulatory concern, nominal distances to other sound isopleths 
down to 120 dB re 1 [mu]Pa (rms) shall be reported in increments of 10 
dB.
    Data shall be previewed in the field immediately after download 
from the hydrophone instruments. An initial sound source analysis shall 
be supplied to NMFS and the airgun operators within 120 hours of 
completion of the measurements. The report shall indicate the distances 
to sound levels based on fits of empirical transmission loss formulae 
to data in the endfire and broadside directions. A more detailed report 
will be issued to NMFS as part of the 90-day report following 
completion of the acoustic program.
B. Seismic Hydrophone Streamer Recordings of Vessel Sounds
    Although some measurements of icebreaking sounds have previously 
been reported, acoustic data on vessels traveling through relatively 
light ice conditions, as will be the case during the proposed survey, 
are not available. In order to gather additional information on the 
sounds produced by this type of icebreaking, ION proposes to use the 
hydrophones in the seismic streamer on a routine basis throughout the 
survey. Once every hour the airguns would not be fired at 2 consecutive 
intervals (one seismic pulse interval is typically ~18 seconds, so 
there will be ~54 seconds between seismic pulses at this time) and 
instead a period of background sounds would be recorded, including the 
sounds generated by the vessels. Over the course of the survey this 
should generate as many as 750 records of vessel sounds traveling 
through various ice conditions (from open water to 100% cover juvenile 
first year ice or lighter multi-year ice). The acoustic data during 
each sampling period from each hydrophone along the 9 km (5.6 mi) 
streamer would be analyzed and used to estimate the propagation loss of 
the vessel sounds. The acoustic data received from the hydrophone 
streamer would be recorded at an effective bandwidth of 0-400 Hz. In 
order to estimate sound energy over a larger range of frequencies 
(broadband), results from previous measurements of icebreakers could be 
generalized and added to the data collected during this project.
C. Over-Winter Acoustic Recorders
    In order to collect additional data on the propagation of sounds 
produced by icebreaking and seismic airguns in ice-covered waters, as 
well as on vocalizing marine mammals, ION intends to collaborate with 
other Industry operators to deploy acoustic recorders in the Alaskan 
Beaufort Sea in fall 2012, to be retrieved during the 2013 open-water 
season.
    During winter 2011-2012, AURAL acoustic recorders were deployed at 
or near each of the 5 acoustic array sites

[[Page 65078]]

established by Shell for monitoring the fall bowhead whale migration 
through the Beaufort Sea, as well as one site near the shelf break in 
the central Alaskan Beaufort Sea. These recorders will be retrieved in 
July 2012, when Shell deploys Directional Autonomous Seafloor Acoustic 
Recorders (DASARs) at 5 array locations. When the DASAR arrays are 
retrieved in early October, ION intends to coordinate with Shell to re-
deploy the 6 AURAL recorders to the same locations used during the 
2011-2012 winter. Redeploying the recorders in the same locations will 
provide comparable data from a year with little to no offshore 
industrial activity (2011) to a year with more offshore industrial 
activity (2012). Acoustic data from the over-winter recorders will be 
analyzed to address the following objectives:
     Characterize the sounds and propagation distances produced 
by ION's source vessel, icebreaker, and airguns on and to the edge of 
the U.S. Beaufort Sea shelf,
     Characterize ambient sounds and marine mammal calls during 
October and November to assess the relative effect of ION's seismic 
survey on the background conditions, and to characterize marine mammal 
calling behavior, and
     Characterize ambient sound and enumerate marine mammal 
calls through acoustic sampling of the environment form December 2012 
through July 2013, when little or no anthropogenic sounds are expected.
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 independent peer review panels to review ION's 
mitigation and monitoring plan in its IHA applications submitted in 
2010 and 2011 for taking marine mammals incidental to the proposed 
seismic survey in the Beaufort and Chukchi Seas, during 2010 and 2011. 
The panels met on March 25 and 26, 2010, and on March 9, 2011, and 
provided their final report to NMFS on April 22, 2010 and on April 27, 
2011, respectively. The full panel reports can be viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    ION's proposed 2012 action is essentially the same as described in 
its 2010 and 2011 IHA applications. NMFS worked with ION in 2010 and 
2011 to address the peer review panels' recommendations on its 2010 and 
2011 4MPs. Since ION's 2012 4MP addressed all issues raised during the 
2010 and 2011 peer reviews and incorporated all of NMFS' requested 
changes, NMFS decided it was not necessary to conduct a peer-review of 
ION's 2012 4MP. All actions based on the 2010 and 2011 panel review are 
discussed in the Federal Register notice for the proposed IHA (77 FR 
49922; August 17, 2012), and is not repeated here.
Reporting Measures
(1) SSV Report
    A report on the preliminary results of the acoustic verification 
measurements, including as a minimum the measured 190-, 180-, 160-, and 
120-dB re 1 [mu]Pa (rms) radii of the airgun arrays shall be submitted 
within 120 hr after collection and analysis of those measurements at 
the start of the field season. This report shall specify the distances 
of the exclusion zones that were adopted for the marine survey 
activities.
(2) Field Reports
    Throughout the survey program, the observers shall prepare a report 
each day or at such other intervals as the IHA may specify (if issued), 
or ION may require summarizing the recent results of the monitoring 
program. The field reports shall summarize the species and numbers of 
marine mammals sighted. These reports shall be provided to NMFS and to 
the survey operators.
(3) Technical Reports
    The results of the vessel-based monitoring, including estimates of 
``take by harassment'', shall be presented in the 90-day and final 
technical reports. Reporting shall address the requirements established 
by NMFS in the IHA. The technical report shall include:
    (a) Summaries of monitoring effort: total hours, total distances, 
and distribution of marine mammals through the study period accounting 
for sea state and other factors affecting visibility and detectability 
of marine mammals;
    (b) Methods, results, and interpretation pertaining to all acoustic 
characterization work and vessel-based monitoring;
    (c) Analyses of the effects of various factors influencing 
detectability of marine mammals including sea state, number of 
observers, and fog/glare;
    (d) Species composition, occurrence, and distribution of marine 
mammal sightings including date, water depth, numbers, age/size/gender 
categories, group sizes, and ice cover; and
    (e) Analyses of the effects of survey operations:
     Sighting rates of marine mammals during periods with and 
without airgun activities (and other variables that could affect 
detectability);
     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''.
(4) Notification of Injured or Dead Marine Mammals
    In addition to the reporting measures proposed by ION, NMFS will 
require that ION notify NMFS' Office of Protected Resources and NMFS' 
Stranding Network of sighting an injured or dead marine mammal in the 
vicinity of marine survey operations. Depending on the circumstance of 
the incident, ION shall take one of the following reporting protocols 
when an injured or dead marine mammal is discovered in the vicinity of 
the action area.
    (a) In the unanticipated event that survey operations clearly cause 
the take of a marine mammal in a manner prohibited by this 
Authorization, such as an injury, serious injury or mortality (e.g., 
ship-strike, gear interaction, and/or entanglement), ION shall 
immediately cease survey operations and immediately report the incident 
to the Supervisor of Incidental Take Program, Permits and Conservation 
Division, Office of Protected Resources, NMFS, and the Alaska Regional 
Stranding Coordinators. The report must include the following 
information:
    (i) Time, date, and location (latitude/longitude) of the incident;
    (ii) The name and type of vessel involved;
    (iii) The vessel's speed during and leading up to the incident;
    (iv) Description of the incident;
    (v) Status of all sound source use in the 24 hours preceding the 
incident;
    (vi) Water depth;
    (vii) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);

[[Page 65079]]

    (viii) Description of marine mammal observations in the 24 hours 
preceding the incident;
    (ix) Species identification or description of the animal(s) 
involved;
    (x) The fate of the animal(s); and
    (xi) Photographs or video footage of the animal (if equipment is 
available).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with ION to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. ION may not resume their 
activities until notified by NMFS via letter, email, or telephone.
    (b) In the event that ION discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
ION will immediately report the incident to the Supervisor of the 
Incidental Take Program, Permits and Conservation Division, Office of 
Protected Resources, NMFS, and the Alaska Regional Stranding 
Coordinators. The report must include the same information identified 
above. Activities may continue while NMFS reviews the circumstances of 
the incident. NMFS will work with ION to determine whether 
modifications in the activities are appropriate.
    (c) In the event that ION discovers an injured or dead marine 
mammal, and the lead PSO determines that the injury or death is not 
associated with or related to the activities authorized in the IHA (if 
issued) (e.g., previously wounded animal, carcass with moderate to 
advanced decomposition, or scavenger damage), ION shall report the 
incident to the Supervisor of the Incidental Take Program, Permits and 
Conservation Division, Office of Protected Resources, NMFS, and the 
Alaska Regional Stranding Coordinators, within 24 hours of the 
discovery. ION shall provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network. ION can continue its 
operations under such a case.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here 
(military readiness activities), 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]. For the most 
part, only take by Level B behavioral harassment is anticipated as a 
result of the proposed marine seismic survey. However, NMFS has 
determined that Level A takes of a few individuals of marine mammals 
could occur if the animals are unable to bedetected within the 
exclusion zones for a prolonged period of time. Although NMFS believes 
this is not likely, NMFS is proposing to authorize limited takes from 
Level A harassment. Anticipated impacts to marine mammals are 
associated with noise propagation from the seismic airgun(s) and the 
icebreaking used during the seismic survey.
    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 marine survey programs might include 
one or more of the following: tolerance; 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.
    NMFS uses the 160 dB and 120 dB re 1 [mu]Pa (rms) isopleths to 
indicate the onset of Level B harassment by seismic airgun impulses and 
by icebreaking noises, respectively. ION provided calculations for the 
160-dB and 120-dB isopleths produced by these active acoustic sources 
and then used those isopleths to estimate takes by harassment. NMFS 
used the calculations to make preliminary findings under the MMPA. ION 
provided a full description of the methodology used to estimate takes 
by harassment in its IHA application (see ADDRESSES), which is also 
described in the following sections.
    ION has requested an authorization to take ten marine mammal 
species by Level B harassment. These ten marine mammal species are: 
beluga whale, harbor porpoise, bowhead whale, gray whale, humpback 
whale, minke whale, bearded seal, ringed seal, spotted seal, and ribbon 
seal. However, NMFS does not anticipate that humpback whales are likely 
to be encountered during the season of ION's icebreaking seismic 
survey. Therefore, NMFS determined that only nine of the species could 
be affected and potentially taken by harassment. In addition, although 
unlikely, NMFS determined that Level A takes of beluga whales, bowhead 
whales, and ringed seals could also occur, as the proposed monitoring 
and mitigation measures may not be 100% effective due to ice coverage 
and extended periods of darkness. Regardless, our analysis has led us 
to conclude that marine mammals will likely avoid the sound source 
thereby minimizing the probability of exposure at a level that would 
equate to Level A harassment.

Basis for Estimating ``Take by Harassment''

    As stated previously, it is current NMFS practice to estimate take 
by Level A harassment for received levels above 180 dB re 1 [mu]Pa 
(rms) for cetaceans and 190 dB re 1 [mu]Pa (rms) for pinnipeds, and 
take by Level B harassment for all marine mammals under NMFS 
jurisdiction by impulse sounds at a received level above 160 dB re 1 
[mu]Pa (rms) and by non-impulse sounds at a received level above 120 dB 
re 1 [mu]Pa (rms). However, not all animals are equally affected by the 
same received noise levels and, as described earlier, in most cases 
marine mammals are not likely to be taken by Level A harassment 
(injury) when exposed to received levels higher than 180 dB for a brief 
period of time.
    For behavioral harassment, marine mammals will likely not show 
strong reactions (and in some cases any reaction) until sounds are much 
stronger than 160 or 120 dB (for impulse and continuous sounds, 
respectively). Southall et al. (2007) provide a severity scale for 
ranking observed behavioral responses of both free-ranging marine 
mammals and laboratory subjects to various types of anthropogenic sound 
(see Table 4 in Southall et al. (2007)). Tables 7, 9, and 11 in 
Southall et al. (2007) outline the numbers of low-frequency cetaceans, 
mid-frequency cetaceans, and pinnipeds in water, respectively, reported 
as having behavioral responses to multi-pulses in 10-dB received level 
increments. These tables illustrate that the more severe reactions did 
not occur until sounds were much higher than 160 dB re 1 [mu]Pa (rms).
    Anticipated takes would include ``takes by harassment'' involving 
temporary changes in behavior (Level B harassment) and TTS (Level B 
harassment). NMFS does not consider injury (Level A harassment) to be 
likely, however, due to the limited

[[Page 65080]]

effectiveness of monitoring and mitigation measures for animals 
undetected under the ice and/or during the long periods of darkness, a 
small amount of Level A harassment takes are also proposed to be 
authorized. The sections below describe methods used to estimate ``take 
by harassment'' and present estimates of the numbers of marine mammals 
that might be affected during the proposed seismic survey in the U.S. 
Beaufort Sea. The estimates are based on data obtained during marine 
mammal surveys in the Beaufort Sea and on estimates of the sizes of the 
areas where effects could potentially occur. In some cases, these 
estimates were made from data collected from regions and habitats that 
differed from the proposed project area. Adjustments to reported 
population or density estimates were made on a case by case basis to 
account for differences between the source data and the available 
information on the distribution and abundance of the species in the 
project area. This section provides estimates of the number of 
potential ``exposures'' to impulsive sound levels >=160 dB re 1 [mu]Pa 
(rms), non-pulse sound levels >=120 dB (rms) from icebreaking, and also 
includes estimates of exposures to >=180 dB (rms) for cetaceans and 
>=190 dB (rms) for seals.
    Although several systematic surveys of marine mammals have been 
conducted in the southern Beaufort Sea during spring and summer, few 
data (systematic or otherwise) are available on the distribution and 
numbers of marine mammals during the early winter period of this 
survey, particularly in the northern Beaufort Sea. The main sources of 
distributional and numerical data used in deriving the estimates are 
described in the next subsection. There is some uncertainty about how 
representative those data are and the assumptions used below to 
estimate the potential ``take by harassment''. However, the approach 
used here is accepted by NMFS as the best available at this time. That 
is, we calculated the estimated take by multiplying the ensonified area 
by the density of marine mammals. The following estimates are based on 
a consideration of the number of marine mammals that might be disturbed 
appreciably by ~7,250 line kilometers (4,505 line miles) of seismic 
surveys across the Beaufort Sea and, to a lesser extent, the northern 
Chukchi Sea.

Marine Mammal Density Estimates

    This section describes the estimated densities of marine mammals 
that may occur in the survey area. The area of water that may be 
ensonified to various levels is described below. Although a marine 
mammal may be exposed to icebreaking sounds >=120 dB (rms) or airgun 
sounds >=160 dB (rms), this does not mean that every individual exposed 
at these levels will actually exhibit a disruption of behavioral 
patterns in response to the sound source. Not all animals react to 
sounds at this low level, and many will not show strong reactions (and 
in some cases any reaction) until sounds are much stronger. There are 
several variables that determine whether or not an individual animal 
will exhibit a response to the sound, such as the age of the animal, 
previous exposure to this type of anthropogenic sound, habituation, 
etc.
    The survey has been designed to minimize interactions with marine 
mammals by planning to conduct the work at times and in areas where the 
relative density of marine mammals is expected to be quite low. The 
survey will begin in offshore waters (>1,000 m [3,281 ft] deep) of the 
eastern U.S. Beaufort Sea (east survey area) in mid-October. Weather 
and ice permitting, the waters <1,000 m (3,281 ft) deep will not be 
surveyed until mid-October and thereafter, in order to avoid migrating 
bowhead whales. The western U.S. Beaufort Sea and north-eastern Chukchi 
Sea (west survey area) is not expected to be surveyed until late 
October through December.
    Separate densities were calculated for habitats specific to 
cetaceans and pinnipeds. For cetaceans, densities were estimated for 
areas of water depth <200 m (656 ft), 200-1,000 m (656-3,281 ft), and 
>1,000 m (3,281 ft), which approximately correspond to the continental 
shelf, the continental slope, and the abyssal plain, respectively. 
Separate densities of both cetacean and pinnipeds were also estimated 
for the east and west survey areas within each water depth category. 
However, pinniped densities in the west survey area and <200 m (656 ft) 
water depth category were further sub-divided into <35 m (115 ft) and 
35-200 m (115-656 ft) depth categories. This was done because the west 
survey area is not expected to be surveyed until November-December, and 
based on historic sea ice data (NOAA National Ice Center, available 
online at www.natice.noaa.gov), it is expected that substantial amounts 
of sea ice, including shorefast ice, will be present in the west survey 
area at that time. Past studies have found that seal densities in ice-
covered areas of the Beaufort Sea are different where water depths are 
<35 m (115 ft) and >35 m (Moulton et al., 2002; Frost et al., 2004); 
therefore, densities were calculated separately for these water depths. 
The north-eastern Chukchi Sea is composed of mostly continental shelf 
waters between 30 m (98 ft) and 200 m (656 ft) in depth, so only a 
single density estimate for each marine mammal species was used in that 
area. Since most marine mammals will be continuing their southerly 
migration in November and early December, the same density estimates 
for continental shelf waters in the west survey area of the Beaufort 
Sea were used in the Chukchi Sea. When the seismic survey area is on 
the edge of the range of a species at this time of year, it is assumed 
that the average density along the seismic trackline will be 10% 
(0.10x) the density determined from available survey data within the 
main range. Density estimates for the Chukchi Sea during the period of 
November-December were taken from the west survey density estimates at 
the appropriate depth.
    Detectability bias, quantified in part by f(0), is associated with 
diminishing sightability with increasing lateral distance from the 
survey trackline. Availability bias, g(0), refers to the fact that 
there is <100% probability of sighting an animal that is present along 
the survey trackline. Some sources used below took account of one or 
both of these correction factors in reporting densities. When these 
factors had not been accounted for, the best available correction 
factors from similar studies and/or species were applied to reported 
results. Details regarding the application of correction factors are 
provided below for each species.

(1) Cetaceans

    Beluga Whales: Beluga density estimates were calculated based on 
aerial survey data collected in October in the eastern Alaskan Beaufort 
Sea by the NMML (as part of the Bowhead Whale Aerial Survey Project 
(BWASP) program funded by BOEM) in 2007-2010. They reported 31 
sightings of 66 individual whales during 1,597 km (992 mi) of on-
transect effort over waters 200-2,000 m (656-6,562 ft) deep. An f(0) 
value of 2.326 was applied and it was calculated using beluga whale 
sightings data collected in the Canadian Beaufort Sea (Innes et al. 
2002). A g(0) value of 0.419 was used that represents a combination of 
ga(0) = 0.55 (Innes et al., 2002) and gd(0) = 0.762 (Harwood et al., 
1996). The resulting density estimate (0.1169 individuals/km\2\; Table 
2 in this document) was applied to areas of 200-1,000 m (656 -3,281 
ft). There were 3 sightings of 4 individual beluga whales during 7,482 
km (4,649 mi) of on-transect effort over waters 0-200 m (0-656 ft) deep 
during this same time

[[Page 65081]]

period. Using the same f(0) and g(0) values from above, the resulting 
density estimate for continental shelf waters (0-200 m deep) is 0.0015 
individuals/km\2\ (Table 2 in this document). The density estimate for 
waters >1000 m (3,281 ft) deep was estimated as 40% of the 200-1,000 m 
(656-3,281 ft) density based on the relative number of sightings in the 
two water depth categories. For all water depth and survey area 
categories, the maximum beluga density estimates represent the mean 
estimates multiplied by four to allow for chance encounters with 
unexpected large groups of animals or overall higher densities than 
expected.
    Beluga density estimates for the west survey area, which is planned 
to be surveyed beginning in November, represent the east survey area 
estimates multiplied by 0.1 because the Beaufort Sea and north-eastern 
Chukchi Sea is believed to be at the edge of the species' range in 
November-December. Belugas typically migrate into the Bering Sea for 
the winter (Allen and Angliss, 2011) and are not expected to be present 
in the study area in high numbers in November-December. Satellite 
tagging data support this and indicate belugas migrate out of the 
Beaufort Sea in the October-November period (Suydam et al., 2005).
    Bowhead Whales: Bowhead whale density estimates were calculated 
based on aerial survey data collected in the Beaufort Sea as part of 
the BWASP program funded by BOEM. The average density estimate was 
based on surveys in October 2007-2010 and the maximum density estimate 
was based on surveys conducted in October 1997-2004. The earlier data 
were used to calculate the maximum estimate because they include some 
years of unusually high numbers of bowhead sightings in the western 
Alaskan Beaufort Sea at that time of year. The 2007-2010 data included 
25 on-transect sightings collected during 7,482 km (4,649 mi) of effort 
over waters 0-200 m (0-656 ft) deep in the eastern Alaskan Beaufort 
Sea. The 1997-2004 data included 147 on-transect sightings of 472 
individual whales collected during 20,340 km (12,639 mi) of effort over 
waters 0-200 m (0-656 ft) deep in the eastern Alaskan Beaufort Sea. An 
f(0) correction factor of 2.33 used in the density calculation was the 
result of a weighted average of the f(0) values applied to each of the 
flights (Richardson and Thomson, 2002). The multiplication of ga(0) = 
0.144 and gd(0) = 0.505 correction factors reported in Richardson and 
Thomson (2002) gave the g(0) value of 0.0727 used in the density 
calculation. The resulting density estimates (0.0942 whales/km\2\ and 
0.3719 whales/km\2\) represent the average and maximum densities, 
respectively for October for areas of <200 m (656 ft) water depth, and 
are referred to below as the reference density for bowhead whales.
    Because bowhead whale density is typically higher in continental 
shelf waters of the Beaufort Sea in early October, the survey has been 
planned to start in the eastern U.S. Beaufort Sea in waters deeper than 
1,000 m (3,281 ft; ice conditions permitting), where bowhead density is 
expected to be much lower. Survey activity in shallower waters will 
proceed from east to west starting later in October as bowhead whales 
migrate west out of the Beaufort Sea. The nearshore lines in the east 
survey area will be surveyed during late October. Bowhead density in 
the east survey area in waters <200 m (656 ft) deep was estimated by 
taking ten percent of the reference density above (Table 2 in this 
document). This adjustment was based on data from Miller et al. (2002) 
that showed a ~90% decrease in bowhead whale abundance in the eastern 
Alaskan Beaufort Sea from early to late October.
    Bowhead whale densities in intermediate (200-1,000 m [656-3,281 
ft]) and deep (>1,000 m [3,281 ft]) water depths in the east survey 
area are expected to be quite low. Ninety-seven percent of sightings 
recorded by MMS aerial surveys 1997-2004 occurred in areas of water 
depth <200 m (656 ft) (Treacy, 1998, 2000, 2002a, 2000b; Monnett and 
Treacy, 2005). Therefore, density estimates for areas of water depth 
200-1,000 m (656-3,281 ft) were estimated to be ~3% of the values for 
areas with depth <200 m (656 ft). This is further supported by Mate et 
al. (2000), who found that 87% of locations from satellite-tagged 
bowhead whales occurred in areas of water depth <100 m (328 ft). In 
areas with water depth >1,000 m (3,281 ft), ~4,225 km (2,625 mi) of 
aerial survey effort occurred during October 1997-2004; however, no 
bowhead sightings were recorded. The effort occurred over eight years, 
so it is unlikely that this result would have been influenced by ice 
cover or another single environmental variable that might have affected 
whale distribution in a given year. Therefore, a minimal density 
estimate (0.0001 whales/km\2\) was used for areas with water depth 
>1,000 m (3,281 ft).
    Several sources were used to estimate bowhead whale density in the 
west survey area, including the north-eastern Chukchi Sea, which is 
expected to be surveyed beginning in late October or early November. 
Mate et al. (2000) found that satellite-tagged bowhead whales in the 
Beaufort Sea travelled at an average rate of 88 km (55 mi) per day. At 
that rate, an individual whale could travel across the extent of the 
east survey area in four days and across the entire east-west extent of 
the survey area in ten days, if it did not stop to feed during its 
migration, as bowhead whales have been observed to do earlier in the 
year (Christie et al., 2010). Also, Miller et al. (2002) presented a 
10-day moving average of bowhead whale abundance in the eastern 
Beaufort Sea using data from 1979-2000 that showed a decrease of ~90% 
from early to late October. Based on these data, it is expected that 
almost all whales that had been in the east survey area during early 
October would likely have migrated beyond the survey areas by November-
December. In addition, kernel density estimates and animal tracklines 
generated from satellite-tagged bowhead whales, along with acoustic 
monitoring data, suggest that few bowhead whales are present in the 
proposed survey area in November (near Point Barrow), and no whales 
were present in December (ADFG, 2010; Moore et al., 2010). Therefore, 
density estimates for the <200 m (656 ft) and 200-1,000 m (656-3,281 
ft) water depth categories in the west survey area were estimated to be 
one tenth of those estimates for the east survey area. Minimal density 
estimates (0.0001 whales/km\2\) were used for areas of water depth 
>1,000 m (3,281 ft).
    Other Cetaceans: Other cetacean species are not expected to be 
present in the area at the time of the planned survey. These species, 
including humpback and fin whales, typically migrate during autumn and 
are expected to be south of the proposed survey area by the October-
December period. Gray whales have been detected near Point Barrow 
during the period of the proposed project, and even throughout the 
winter (Moore et al., 2006; Stafford et al., 2007). Authorization for 
minimal takes of other cetacean species that are known to occur in the 
Beaufort Sea during the summer have been requested in case of a chance 
encounter of a few remaining individuals.

[[Page 65082]]



 Table 2--Expected Densities of Cetaceans in the Arctic Ocean in October-December by Water Depth and Survey Area
----------------------------------------------------------------------------------------------------------------
                          Species                                <200 m          200-1,000 m        >1,000 m
----------------------------------------------------------------------------------------------------------------
Beaufort East Survey Area
    Beluga whale..........................................            0.0015            0.1169            0.0468
    Harbor porpoise.......................................            0.0001            0.0001            0.0001
    Bowhead whale.........................................            0.0094            0.0028            0.0001
    Gray whale............................................            0.0001            0.0001            0.0001
    Minke whale...........................................            0.0001            0.0001            0.0001
Beaufort West Survey Area
    Beluga whale..........................................            0.0002            0.0117            0.0047
    Harbor porpoise.......................................            0.0001            0.0001            0.0001
    Bowhead whale.........................................            0.0009            0.0003            0.0001
    Gray whale............................................            0.0001            0.0001            0.0001
    Minke whale...........................................            0.0001            0.0001            0.0001
Chukchi Survey Area
    Beluga whale..........................................            0.0002  ................  ................
    Harbor porpoise.......................................            0.0001  ................  ................
    Bowhead whale.........................................            0.0009  ................  ................
    Gray whale............................................            0.0001  ................  ................
    Minke whale...........................................            0.0001  ................  ................
----------------------------------------------------------------------------------------------------------------

(2) Pinnipeds
    In polar regions, most pinnipeds are associated with sea ice, and 
typical census methods involve counting pinnipeds when they are hauled 
out on ice. In the Beaufort Sea, surveys typically occur in spring when 
ringed seals emerge from their lairs (Frost et al., 2004). Depending on 
the species and study, a correction factor for the proportion of 
animals hauled out at any one time may or may not have been applied 
(depending on whether an appropriate correction factor was available 
for the particular species and area). By applying a correction factor, 
the total density of the pinniped species in an area can be estimated. 
Only the animals in water would be exposed to the pulsed sounds from 
the airguns; however, densities that are presented generally represent 
either only the animals on the ice or all animals in the area. 
Therefore, only a fraction of the pinnipeds present in areas where ice 
is present (and of sufficient thickness to support hauled-out animals) 
would be exposed to seismic sounds during the proposed seismic survey. 
Individuals hauled out on ice in close proximity to the vessels are 
likely to enter the water as a reaction to the passing vessels, and the 
proportion that remain on the ice will likely increase with distance 
from the vessels.
    Ringed Seals: Ringed seal density for the east survey area for 
waters <1000 m (3,281 ft) deep was estimated using vessel-based data 
collected in the Beaufort Sea during autumn (Sep-Oct) 2006-2008 and 
reported by Savarese et al. (2010; Table 3 in this document). 
Correction factors for sightability and availability were used when the 
authors calculated the estimates, so no further adjustments were 
required. For the east survey area for waters >1000 m (3,281 ft) deep, 
few data on seal distribution are available. Harwood et al. (2005) 
recorded a ringed seal sighting in the Beaufort Sea in an area where 
water depth was >1,000 m (3,281 ft) in September-October 2002 during an 
oceanographic cruise. It is therefore possible that ringed seals would 
occur in those areas, and their presence would likely be associated 
with ephemeral prey resources. If a relatively warm surface eddy formed 
that concentrated prey in offshore areas at depths that would be 
possible for ringed seals to access, it is possible that seals would be 
attracted to it. A warm eddy was found in the northern Beaufort Sea in 
October 2002 in an area where water depth was >1,000 m (3,281 ft) 
(Crawford, 2010), so it is possible that such an oceanographic feature 
might develop again and attract seals offshore. However, it is unclear 
whether such a feature would attract many seals, especially since the 
marine mammal observers present on the ship in 2002 did not observe 
very many seals associated with the offshore eddy. In the absence of 
standardized survey data from deep-water areas, but with available data 
suggesting densities are likely to be quite low, minimal density 
estimates (0.0001 seals/km\2\) were used in areas where water depth is 
>1,000 m (3,281 ft). For all water depth categories in the east survey 
area, the maximum ringed seal density was assumed to be the mean 
estimate multiplied by four to allow for chance encounters with 
unexpected large groups of animals or overall higher densities than 
expected.
    Habitat zones and associated densities were defined differently in 
the west survey area, which will be surveyed in November-December, 
because more ice is expected to be encountered at that time than in 
October (NOAA National Ice Center: www.natice.noaa.gov). The density 
estimates for the west survey area were calculated using aerial survey 
data collected by Frost et al. (2004) in the Alaskan Beaufort Sea 
during the spring. A g(0) correction factor of 0.60 from tagging data 
reported by Bengtson et al. (2005) was used to adjust all density 
estimates from Frost et al. (2004) described below. Seal distribution 
and density in spring, prior to breakup, are thought to reflect 
distribution patterns established earlier in the year (i.e., during the 
winter months; Frost et al., 2004). Density estimates were highest 
(1.00-1.33 seals/km\2\) in areas of water depth 3-35 m (10-115 ft), and 
decreased (0-0.77 seals/km\2\) in water >35 m (115 ft) deep. The mean 
density estimate used for areas with water depth <35 m (Table 4 in this 
document) was estimated using an average of the pack ice estimates 
modeled by Frost et al. (2004). The maximum estimate for the same area 
is the maximum observed density for areas of water depth 3-35 m (10-115 
ft) in Frost et al. (2004). The mean density estimate used for areas 
with 35-200 m (115-656 ft) water depth is the modeled value for water 
depth >35 m (115 ft) from Frost et al. (2004). The maximum estimate is 
the maximum observed density for areas with >35 m (115 ft) water depth 
in Frost et al. (2004). Because ringed seal density tends to decrease 
with increasing water depth (Moulton et al., 2002; Frost et al., 2004), 
ringed seal density was estimated to be minimal in areas of >200 m (656 
ft) water depth.

[[Page 65083]]

    In the Chukchi Sea, ringed seal densities were taken from offshore 
aerial surveys of the pack ice zone conducted in spring 1999 and 2000 
(Bengtson et al., 2005). The average density from those two years 
(weighted by survey effort) was 0.4892 seals/km\2\. This value served 
as the average density while the highest density from the two years, 
(0.8100 seals/km\2\ in 1999) was used as the maximum density.
    Other Seal Species: Other seal species are expected to be less 
frequent in the study area during the period of this survey. Bearded 
and spotted seals would be present in the area during summer, and 
possibly ribbon seals as well, but they generally migrate into the 
southern Chukchi and Bering seas during fall (Allen and Angliss, 2011). 
Few satellite-tagging studies have been conducted on these species in 
the Beaufort Sea, winter surveys have not been conducted, and a few 
bearded seals have been reported over the continental shelf in spring 
prior to general breakup. However, three bearded seals tracked in 2009 
moved south into the Bering Sea along the continental shelf by November 
(Cameron and Boveng, 2009). It is possible that some individuals, 
bearded seals in particular, may be present in the survey area. In the 
absence of better information from the published literature or other 
sources that would indicate significant numbers of any of these species 
might be present, minimal density estimates were used for all areas and 
water depth categories for these species, with the estimates for 
bearded seals assumed to be slightly higher than those for spotted and 
ribbon seals (Tables 3 and 4 in this document).

 Table 3--Expected Densities (/km\2\) of Pinnipeds in the East Survey Area of the U.S. Beaufort Sea in
                                                    October.
----------------------------------------------------------------------------------------------------------------
                          Species                                <200 m          200-1,000 m        >1,000 m
----------------------------------------------------------------------------------------------------------------
Ringed seal...............................................            0.0840            0.0840            0.0004
Bearded seal..............................................            0.0004            0.0004            0.0004
Spotted seal..............................................            0.0001            0.0001            0.0001
Ribbon seal...............................................            0.0001            0.0001            0.0001
----------------------------------------------------------------------------------------------------------------


 Table 4--Expected Densities (/km\2\) of Pinnipeds in the Beaufort West and Chukchi Survey Areas of the
                                       Arctic Ocean in November-December.
----------------------------------------------------------------------------------------------------------------
                          Species                                 <35 m           35-200 m           >200 m
----------------------------------------------------------------------------------------------------------------
Beaufort West
    Ringed seal...........................................            1.9375            1.0000            0.0004
    Bearded seal..........................................            0.0004            0.0004            0.0004
    Spotted seal..........................................            0.0001            0.0001            0.0001
    Ribbon seal...........................................            0.0001            0.0001            0.0001
Chukchi Sea
    Ringed seal...........................................  ................            0.4892  ................
    Bearded seal..........................................  ................            0.0004  ................
    Spotted seal..........................................  ................            0.0001  ................
    Ribbon seal...........................................  ................            0.0001  ................
----------------------------------------------------------------------------------------------------------------

Potential Number of Takes by Level B Behavioral Harassment

    Numbers of marine mammals that might be present and potentially 
taken are estimated below based on available data about mammal 
distribution and densities at different locations and times of the year 
as described above.
    The number of individuals of each species potentially exposed to 
received levels >=120 dB re 1 [mu]Pa (rms) or >=160 dB re 1 [mu]Pa 
(rms), depending on the type of activity occurring, within each portion 
of the survey area (east and west) and water depth category was 
estimated by multiplying:
     The anticipated area to be ensonified to >=120 dB re 1 
[mu]Pa (rms) or >=160 dB re 1 [mu]Pa (rms) in each portion of the 
survey area (east and west) and water depth category, by
     The expected species density in that time and location.
    Some of the animals estimated to be exposed, particularly migrating 
bowhead whales, might show avoidance reactions before being exposed to 
>=160 dB re 1 [mu]Pa (rms). Thus, these calculations actually estimate 
the number of individuals potentially exposed to >=160 dB (rms) that 
would occur if there were no avoidance of the area ensonified to that 
level.
(1) Potential Number of Takes by Seismic Airguns at Received Levels 
>=160 dB
    The area of water potentially exposed to received levels of airgun 
sounds >=160 dB (rms) was calculated by using a GIS to buffer the 
planned survey tracklines within each water depth category by the 
associated modeled >=160 dB (rms) distances. The expected sound 
propagation from the airgun array was modeled by JASCO Applied Research 
(Zykov et al., 2010) and is expected to vary with water depth. Survey 
tracklines falling within the <100 m (328 ft), 100-1,000 m (328-3,281 
ft), and >1,000 m (3,281 ft) water depth categories were buffered by 
distances of 27.8 km (17.3 mi), 42.2 km (26.2 mi), and 31.6 km (19.6 
mi), respectively. The total area of water that would be exposed to 
sound >160 dB (rms) on one or more occasions is estimated to be 209,752 
km\2\. A breakdown by water depth classes used in association with 
density estimates is presented in Table 5 in this document and Figure 2 
of the IHA application.
    Based on the operational plans and marine mammal densities 
described above, the estimates of marine mammals potentially exposed to 
sounds >=160 dB (rms) are presented in Table 5 in this document. For 
species likely to be present, the requested numbers are calculated as 
described above. For less common species, estimates were set to minimal 
numbers to allow for chance encounters. Discussion of the number of 
potential exposures is summarized by species in the following 
subsections.
    It is likely that some members of one endangered cetacean species 
(bowhead whale) will be exposed to received

[[Page 65084]]

sound levels >=160 dB (rms) unless bowheads avoid the survey vessel 
before the received levels reach 160 dB (rms). However, the late autumn 
timing and the design of the proposed survey will minimize the number 
of bowheads and other cetaceans that may be exposed to seismic sounds 
generated by this survey. The best estimates of the number of whales 
potentially exposed to >=160 dB (rms) are 282 and 4,315 for bowheads 
and belugas, respectively (Table 5).
    The ringed seal is the most widespread and abundant pinniped 
species in ice-covered Arctic waters, and there is a great deal of 
variation in estimates of population size and distribution of these 
marine mammals. Ringed seals account for the vast majority of marine 
mammals expected to be encountered, and hence exposed to airgun sounds 
with received levels >160 dB (rms) during the proposed marine survey. 
Our analysis, based on our use of summer/fall density data, resulted in 
an overestimation of take of ringed seals (approximately 60,293 ringed 
seals may be exposed to marine survey sounds with received levels >160 
dB (rms)) if they do not avoid the sound source. Other pinniped species 
are not expected to be present in the proposed survey area in more than 
minimal numbers in October-December; however, ION is requesting 
authorization for a small number of harassment ``takes'' of species 
that occur in the area during the summer months in case a few 
individuals are encountered (Table 5 in this document).
    It should be noted that there is no evidence that most seals 
exposed to airgun pulses with received levels 160 dB re 1 [mu]Pa (rms) 
are disturbed appreciably, and even at a received level of 180 dB (rms) 
disturbance is not conspicuous (Harris et al., 2001; Moulton and 
Lawson, 2002). Therefore, for seals, the estimates of numbers exposed 
to >=160 dB re 1 [mu]Pa (rms) greatly exceed the numbers of seals that 
will actually be disturbed in any major or (presumably) biologically 
significant manner.

 Table 5--Estimates of the Possible Numbers of Marine Mammals Exposed to >=160 dB re 1 [mu]Pa (rms) During ION's
                Proposed Seismic Program in the Beaufort and Chukchi Seas, October-December 2012
----------------------------------------------------------------------------------------------------------------
                                                                    Water depth
                    Cetaceans                    ------------------------------------------------      Total
                                                      <200 m        200-1,000 m      >1,000 m
----------------------------------------------------------------------------------------------------------------
Beluga whale....................................              43           1,195           3,077           4,215
Harbor porpoise.................................               9               2              10              21
Bowhead whale...................................             269               3              10             282
Gray whale......................................               9               2              10              21
Minke whale.....................................               9               2              10              21
----------------------------------------------------------------------------------------------------------------
            Pinnipeds (Beaufort East)                               Water depth                        Total
                                                 ------------------------------------------------
                                                       <35 m         35-200 m         >200 m
----------------------------------------------------------------------------------------------------------------
Ringed seal.....................................           1,794             805              25           2,624
Bearded seal....................................               9               4              25              38
Spotted seal....................................               2               1               6               9
Ribbon seal.....................................               2               1               6               9
----------------------------------------------------------------------------------------------------------------
     Pinnipeds (Beaufort West & Chukchi Sea)           <35 m         35-200 m         >200 m           Total
----------------------------------------------------------------------------------------------------------------
Ringed seal.....................................          16,969          40,682              18          57,669
Bearded seal....................................               4              25              18              47
Spotted seal....................................               1               6               5              12
Ribbon seal.....................................               1               6               5              12
----------------------------------------------------------------------------------------------------------------

(2) Potential Number of Takes by Icebreaking at Received Levels >=120 
dB
    As discussed above, based on available information regarding sounds 
produced by icebreaking in various ice regimes and the expected ice 
conditions during the proposed survey, vessel sounds generated during 
ice breaking are likely to have source levels between 175 and 185 dB re 
1 [micro]Pa-m. As described above, we have assumed that seismic survey 
activity will occur along all of the planned tracklines shown in Figure 
1 of ION's IHA application. Therefore, received levels >=160 dB radius 
of 26.7-42.2 km (16.6-26.2 mi; depending on water depth) to each side 
of all of the survey lines was applied for the calculation. Assuming a 
source level of 185 dB re 1 [micro]Pa-m and using the 15logR for 
calculating spreading loss of acoustic intensity, icebreaking sounds 
may be >=120 dB out to a maximum distance of ~21.6 km (13.4 mi). Thus, 
all sounds produced by icebreaking are expected to diminish below 120 
dB re 1 [mu]Pa within the zone where we assume mammals will be exposed 
to >=160 dB (rms) from seismic sounds. Exposures of marine mammals to 
icebreaking sounds with received levels >=120 dB would effectively 
duplicate or ``double-count'' animals already included in the estimates 
of exposure to strong (>=160 dB) airgun sounds. The planned survey 
lines cover a large extent of the U.S. Beaufort Sea, and seismic survey 
activity along all those lines has been assumed in the estimation of 
takes. Any non-seismic periods, when only icebreaking might occur, 
would therefore result in fewer exposures than estimated from seismic 
activities.
    If refueling of the Geo Arctic is required during the survey and 
the Polar Prince transits to and from Canadian waters to acquire 
additional fuel for itself, an additional ~200 km (124 mi) of transit 
may occur. Most of this transit would likely occur through ice in 
offshore waters >200 m (656 ft) in depth. For estimation purposes we 
have assumed 25% of the transit will occur in 200-1,000 m (656-3,281 
ft) of water and the remaining 75% will occur in >1000 m (3,281 ft) of 
water. This results in an estimated ~2,160 km\2\ of water in areas 200-
1,000 m (656-3,281 ft) deep and 6,487 km\2\ in waters >1,000 m (3,281 
ft) deep being ensonified to >=120 dB by icebreaking sounds. Using the 
density estimates for the east survey

[[Page 65085]]

area shown in Tables 2 and 3, the estimated exposures of cetaceans and 
pinnipeds are shown in Table 6 here.

    Table 6--Estimates of the Possible Numbers of Marine Mammals Exposed to >=120 dB re 1 [mu]Pa (rms) During
  Icebreaking Activities Associated With the Preferred Alternative for Refueling During ION's Proposed Seismic
                               Program in the Beaufort Sea, October-December 2012
----------------------------------------------------------------------------------------------------------------
                                                                        Water depth
                          Species                          ------------------------------------       Total
                                                               200-1,000 m        >1,000 m
----------------------------------------------------------------------------------------------------------------
Beluga whale..............................................               253               320               573
Harbor porpoise...........................................                 0                 1                 1
Bowhead whale.............................................                 1                 1                 2
Gray whale................................................                 0                 1                 1
Minke whale...............................................                 0                 1                 1
Ringed seal...............................................               181                 3               184
Bearded seal..............................................                 1                 3                 4
Spotted seal..............................................                 0                 1                 1
Ribbon seal...............................................                 0                 1                 1
----------------------------------------------------------------------------------------------------------------

    If the Polar Prince cannot return to port via Canadian waters, then 
a transit of ~600 km (373 mi) from east to west across the U.S. 
Beaufort would be necessary. Again, it is expected that most of this 
transit would likely occur in offshore waters >200 m (656 ft) in depth. 
For estimation purposes we have assumed 25% of the transit will occur 
in 200-1,000 m (656-3,281 ft) of water and the remaining 75% will occur 
in >1,000 m (3,281 ft) of water. This results in an estimated ~3,240 
km\2\ of water in areas 200-1,000 m (656-3,281 ft) deep and 9,720 km\2\ 
in waters >1,000 m (3,281 ft) deep being ensonified to >=120 dB by 
icebreaking sounds within each half of the U.S. Beaufort Sea, for a 
total of 25,920 km\2\ ensonified across the entire U.S. Beaufort Sea. 
Using the density estimates in Tables 2-3, estimated exposures of 
cetaceans and pinnipeds are shown in Table 7 here.

   Table 7--Estimates of the Possible Numbers of Marine Mammals Exposed to >=120 dB re 1 [mu]Pa  (rms) During
  Icebreaking Activities Associated With the Secondary Alternative for Refueling During ION's Proposed Seismic
                         Program in the Beaufort and Chukchi Seas, October-December 2012
----------------------------------------------------------------------------------------------------------------
                                                                        Water depth
                          Species                          ------------------------------------       Total
                                                               200-1,000 m        >1,000 m
----------------------------------------------------------------------------------------------------------------
Beluga whale..............................................               417               500               917
Harbor porpoise...........................................                 0                 2                 2
Bowhead whale.............................................                 1                 2                 3
Gray whale................................................                 0                 2                 2
Minke whale...............................................                 0                 2                 2
Ringed seal...............................................               273                 8               281
Bearded seal..............................................                 2                 8                10
Spotted seal..............................................                 0                 2                 2
Ribbon seal...............................................                 0                 2                 2
----------------------------------------------------------------------------------------------------------------

Potential Number of Takes by Level B TTS and Level A Harassment

    In the past, because of the likelihood that that individuals will 
avoid exposure at received levels and lengths of time associated with 
PTS, and because of the anticipated effectiveness of mitigation in the 
daytime and in open water, applicants have not requested authorization 
for Level A harassment of marine mammals. However, as noted previously, 
due to the more limited effectiveness of monitoring and mitigation 
measures for animals under ice cover and during long lowlight hours, 
but still considering the likelihood that most individuals will avoid 
exposure at higher levels and the lower densities of some species, NMFS 
is proposing to authorize takes of a small number of marine mammals by 
PTS (Level A harassment or injury) when exposed to received noise 
levels above 180 and 190 dB re 1 [mu]Pa (rms) for prolonged period, 
although this is unlikely to occur.
    The methods used below for estimating the number of individuals 
potentially exposed to sounds >180 or >190 dB re 1 [micro]Pa (rms), 
which are based on over-estimated densities and do not consider 
avoidance or mitigation are therefore corrected to account for 
avoidance and mitigation to estimate a more reasonable number that 
could incur PTS (Level A take) although, for reasons described here and 
further below, NMFS does not anticipate that marine mammals will be 
injured or harmed by the proposed project.
    Only two cetacean species, beluga and bowhead, may be present in 
the Alaskan Beaufort Sea late in the survey period or where extensive 
ice cover is present. Gray whale vocalizations have been recorded 
throughout one winter (2003-2004) in the western Alaskan Beaufort Sea 
near Pt. Barrow (Moore et al. 2006). However, the presence of gray 
whales in October and November in the Alaskan Beaufort Sea does not 
appear to be a regular occurrence or involve a significant number of 
animals when it does occur. NMFS therefore does not anticipate 
exposures of cetacean species, other than belugas or bowheads, to 
received sound levels >=180 dB during periods of ION's in-ice seismic 
survey.
    Beluga whales have shown avoidance of icebreaking sounds at 
relatively low

[[Page 65086]]

received levels. In the Canadian Arctic, belugas showed initial 
avoidance of icebreaking sounds at received levels from 94-105 dB in 
the 20--1,000 Hz band, although some animals returned to the same 
location within 1-2 days and tolerated noise levels as high as 120 dB 
in that band (Finley et al., 1990). Playback experiments of icebreaker 
sounds resulted in 35% of beluga groups showing avoidance at received 
levels between 78-84 dB in the 1/3-octave band centered at 5,000 Hz, or 
8-14 dB above ambient levels (Richardson et al., 1995b). Based on these 
results, it was estimated that reactions by belugas to an actual 
icebreaker would likely occur at ~10 km (6.2 mi) under similar 
conditions. Erbe and Farmer (2000) estimated that zones of disturbance 
from icebreaking sounds could extend 19-46 km (12-28.6 mi) depending on 
various factors. Erbe and Farmer (2000) also estimated that a beluga 
whale would have to remain within 2 km (1.2 mi) of an icebreaker 
backing and ramming for over 20 min to incur small TTS (4.8 dB), and 
within 120 m for over 30 min to incur more significant TTS (12-18 dB). 
Therefore, we expect that the probability of a beluga whale to 
experience TTS is extremely low.
    Aerial and vessel based monitoring of seismic surveys in the 
central Beaufort Sea showed significant avoidance of active airguns by 
belugas. Results of the aerial monitoring suggested an area of 
avoidance out to 10-20 km (6.2-12.4 mi) around an active seismic source 
with higher than expected sighting rates observed at distances 20-30 km 
(12.4-18.6 mi) from the source (Miller et al. 1999; 2005). The nearest 
aerial ``transect'' beluga sighting during seismic activity was at a 
distance of 7.8 km (4.8 mi). Only seven beluga sightings were recorded 
from the survey vessel during the entire study, three of which occurred 
during airgun activity. Two of the seismic period sightings were made 
at the beginning of active airgun periods and the other was during 
seismic testing of a limited number of guns. These sightings occurred 
at distances between 1.54 km and 2.51 km from the vessel. Similarly, 
few beluga whales were observed near seismic surveys in the Alaskan 
Beaufort Sea in 1996-1998 (Richardson 1999), although the beluga 
migration corridor is typically well offshore of where most of the 
seismic survey occurred. Observers on seismic and associated support 
vessels operating in the Alaskan Beaufort Sea during 2006-2008 seasons 
reported no beluga sightings during seismic or non-seismic periods, 
suggesting avoidance of both seismic and vessel sounds (Savarese et 
al., 2010). No mitigation measures during seismic operations (power 
down or shut down of airgun arrays) have been required as a result of 
beluga sightings during surveys in the Chukchi or Beaufort seas in 
2006-2009 (Ireland et al., 2007a, 2007b; Patterson et al., 2007, Funk 
et al., 2008, Ireland et al., 2009b, Reiser et al., 2010).
    Based on the reported avoidance of vessel, icebreaking, and seismic 
sounds by beluga whales, and the low and seasonally decreasing density 
during the time of the proposed survey, the likelihood of beluga whales 
occurring within the >=180 dB zone during the proposed project is 
extremely low. A cautionary estimate that assumes 10% of belugas will 
show no avoidance of the 180 dB zone results in an estimate of 23 
beluga whales exposed to sounds >=180 dB (based on the densities 
described above and the area of water that may be ensonified to >=180 
dB) during the proposed project.
    Bowhead whales have shown similar avoidance of vessel and seismic 
sounds. Less information is available regarding avoidance of 
icebreaking sounds; however, avoidance of the overall activity was 
noted during intensive icebreaking around drill sites in the Alaskan 
Beaufort Sea in 1992. Migrating bowhead whales appeared to avoid the 
area of drilling and icebreaking by ~25 km (15.5 mi) (Brewer et al., 
1993). Also, monitoring of drilling activities in a previous year, 
during which much less icebreaking occurred, showed avoidance by 
migrating bowheads out to ~20 km (12.4 mi). Therefore, the relative 
influence of icebreaking versus drilling sounds is difficult to 
determine.
    Similarly, migrating bowheads avoided the area within ~20 km (12.4 
mi) of nearshore seismic surveys, and showed less avoidance extending 
to ~30 km (18.6 mi) (Miller et al., 1999). Only 1 bowhead was observed 
from the survey vessel during the three seasons (1996-1998) when 
seismic surveys continued into September. Bowheads not actively engaged 
in migration have shown less avoidance of seismic operations. During 
seismic surveys in the Canadian Beaufort Sea in late August and early 
September bowhead whales appeared to avoid an area within ~2 km (1.2 
mi) of airgun activity (Miller and Davis, 2002) and sightings from the 
survey vessel itself were common (Miller et al., 2005). Vessel based 
sightings showed a statistically significant difference of ~600 m 
(1,969 ft) in the mean sighting distances of bowheads (relative to the 
survey vessel) between periods with and without airgun activity. This, 
along with significantly lower sighting rates of bowhead whales during 
periods of airgun activity, suggests that bowheads still avoided close 
approach to the area of seismic operation (Miller and Davis, 2002). 
Results from vessel-based and aerial monitoring in the Alaskan Beaufort 
Sea during 2006-2008 were similar to those described above (Funk et 
al., 2010). Sighting rates from seismic vessels were significantly 
lower during airgun activity than during non-seismic periods. Support 
vessels reported 12 sightings of bowhead whales in areas where received 
levels from seismic were >=160 dB (Savarese et al., 2010). Aerial 
surveys reported bowhead whales feeding in areas where received levels 
of seismic sounds were up to 160 dB. Bowheads were not observed in 
locations with higher received levels (Christie et al., 2010). Based on 
four direct approach experiments in northern Alaskan waters, Ljungblad 
et al. (1988) reported total avoidance of seismic sounds at received 
sound levels of 152, 165, 178, and 165 dB.
    The available information summarized above suggests that bowhead 
whales are very likely to avoid areas where received levels are >=180 
dB re 1 [mu]Pa (rms). Again, making a cautionary assumption that as 
many as 10% of bowheads may not avoid the 180 dB zone around the 
airguns, we calculate that 6 individuals could be exposed to >=180 dB 
(based on the densities described above and the area of water that may 
be ensonified to >=180 dB). During seismic surveys in the Alaskan 
Beaufort Sea in 2007 and 2008, 5 power downs of the full airgun array 
were made due to sightings of bowhead or unidentified mysticete whales 
(8 total individuals) within the >=180 dB exclusion zone. These 
sightings occurred during >8000 km (4,971 mi) of survey effort in good 
conditions plus additional effort in poor conditions (Savarese et al., 
2010), resulting in an estimated 0.625 sightings within the 180 dB 
distance per 1,000 km (620 mi) of seismic activity. Even without 
allowance for the reduced densities likely to be encountered in October 
and especially November, or for the fact that observers will be on duty 
during all daylight hours and will call for mitigation actions if 
whales are sighted within or near the 180 dB distance, this rate would 
suggest that fewer than 8 bowheads may occur within the >=180 dB zone 
during the proposed survey.
    For seals (principally ringed seals), the proportion exhibiting 
avoidance is lower than for cetaceans, and thus the received level at 
which avoidance becomes evident is higher. However, some survey results 
have shown a statistically significant avoidance of the

[[Page 65087]]

190 dB re 1 [mu]Pa (rms) zone, and an assumption that numbers exposed 
to >=190 dB could be calculated from ``non-seismic'' density data is 
not inappropriate. Using similar reasoning as described above for 
cetaceans, we have limited these estimates to ringed seals as the 
presence of other pinniped species is very unlikely during the times 
and locations when exposures to >=190 dB may have an increased 
likelihood of occurrence.
    Monitoring work in the Alaskan Beaufort Sea during 1996-2001 
provided considerable information regarding the behavior of seals 
exposed to seismic pulses (Harris et al., 2001; Moulton and Lawson, 
2002). The combined results suggest that some seals avoid the immediate 
area around seismic vessels. In most survey years, ringed seal 
sightings averaged somewhat farther away from the seismic vessel when 
the airguns were operating than when they were not (Moulton and Lawson, 
2002). Also, seal sighting rates at the water surface were lower during 
airgun array operations than during no-airgun periods in each survey 
year except 1997. However, the avoidance movements were relatively 
small, on the order of 100 m (328 ft) to (at most) a few hundreds of 
meters, and many seals remained within 100-200 m (328-656 ft) of the 
trackline as the operating airgun array passed by.
    During more recent seismic surveys in the Arctic (2006-2009), 
Reiser et al. (2009) also reported a tendency for localized avoidance 
of areas immediately around the seismic source vessel along with 
coincident increased sighting rates at support vessels operating 1-2 km 
(0.62-1.2 mi) away. However, pinnipeds were sighted within the 190 dB 
zone around the operating airguns more frequently than were cetaceans 
within the 180 dB zone. Assuming that 25% of the ringed seals 
encountered may not avoid the 190 dB zone as the airguns approach, we 
calculate that ~277 individuals could be exposed to >=190 dB (based on 
the densities described above and the area of water that may be 
ensonified to >=190 dB). As an alternative estimate, during the same 
>8,000 km (4,971 mi) of monitoring effort in the Alaskan Beaufort Sea 
reported above regarding bowhead whales, 42 observations of seals 
within the 190 dB zone caused power downs of the airguns. This was 
~5.25 power downs per 1,000 km (620 mi) of seismic survey effort. Even 
without allowance for the reduced densities of seals likely to be 
encountered in October-November or for the fact that observers will be 
on duty during all daylight hours and will call for mitigation actions 
if necessary, this rate would suggest that as many as 38 seals may 
occur within the >=190 dB zone during the proposed survey.
    However, as stated earlier, in most circumstances marine mammals 
would avoid areas where intense noise could cause injury, including 
PTS. Although approximately 23 beluga whales, 8 bowhead whales, and 38 
seals (presumably all ringed seals) could theoretically be exposed to 
received levels above 180 dB re 1 [mu] Pa (for whales) and 190 dB re 1 
[mu] Pa (for seals), most of them are likely to avoid areas of intense 
noise and would not incur TTS or PTS (injury). In the unlikely case a 
small number of individuals animals did not avoid the intense noise, 
then TTS or even PTS could occur. Assuming that 10% of the individuals 
that were initially exposed to received levels above 180 dB re 1 [mu] 
Pa (for beluga and bowhead whales) and 190 dB re 1 [mu] Pa (for ringed 
seals) do not vacate the area, and subsequent exposure leads to some 
degree of PTS, then approximately 3 beluga whales, 1 bowhead whale, and 
4 ringed seals could be taken by Level A harassment. However, NMFS 
considers this estimate to be very conservative as explained above.

Estimated Take Conclusions

    Cetaceans--Effects on cetaceans are generally expected to be 
restricted to avoidance of an area around the seismic survey and short-
term changes in behavior, falling within the MMPA definition of ``Level 
B harassment,'' and possibly mild TTS (Level B harassment), or PTS 
(Level A harassment), though the latter is not likely.
    Using the 160 dB (for pulse) and 120 dB (for non-pulse) criteria, 
the average estimates of the numbers of individual cetaceans exposed to 
sounds 160 dB and 120 dB re 1 [mu]Pa (rms) represent varying 
proportions of the populations of each species in the Beaufort Sea and 
adjacent waters. For species listed as ``endangered'' under the ESA, 
the estimates include approximately 284 bowheads. This number is 
approximately 1.86% of the Bering-Chukchi-Beaufort population of 
>15,233 assuming 3.4% annual population growth from the 2001 estimate 
of >10,545 animals (Zeh and Punt 2005). For other cetaceans that might 
occur in the vicinity of the marine seismic survey in the Chukchi Sea, 
they also represent a very small proportion of their respective 
populations. The average estimates of the number of beluga whales, 
harbor porpoises, gray whales, and minke whales that might be exposed 
to 160 dB and 120 dB re 1 [mu] Pa (rms) are 5,232, 23, 23, 
and 23, when the secondary alternative for refueling is being 
considered. These numbers represent 13.33%, 0.05%, 0.12%, and 1.87% of 
these species' respective populations in the proposed action area. If 
ION selects the preferred alternative for refueling, the estimated 
takes for beluga would be reduced to 4,888 animals, or 12.45% of the 
population, which are still based on overestimated densities of these 
animals for the winter season.
    Seals--A few seal species are likely to be encountered in the study 
area, but ringed seal is by far the most abundant in this area. The 
average estimates of the numbers of individuals exposed to sounds at 
received levels 160 dB and 120 dB re 1 [mu] Pa (rms) during 
the proposed icebreaking seismic survey are as follows: ringed seals 
(60,574), bearded seals (95), spotted seals (23), and ribbon seals 
(23), when the secondary alternative for refueling is being considered. 
These numbers represent 24.33%, 0.04%, 0.04%, and 0.05% of Alaska 
stocks of ringed, bearded, spotted, and ribbon seals. If ION selects 
the preferred alternative for refueling, the estimated takes for 
ringed, bearded, spotted, and ribbon seals would drop to 60,477, 89, 
22, and 22, respectively, which in turn represent 24.29%, 0.04%, 0.04%, 
0.04% of Alaska stocks of these species, based on overestimated 
densities of these animals for the winter season.

Negligible Impact and Small Numbers Analysis and Determination

    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.
    Most of the takes from ION's proposed icebreaking seismic surveys 
are expected to be Level B harassment, i.e., behavioral disturbance 
with a slight likelihood of mild TTS. However, it is possible that PTS 
(Level A harassment) given the lowered effectiveness of monitoring 
measures are during extensive ice coverage and prolonged periods of 
darkness. Although it is possible that some individual marine mammals 
may be exposed to sounds from marine survey activities more than

[[Page 65088]]

once, this is not expected to happen extensively since both the animals 
and the survey vessels will be moving constantly in and out of the 
survey areas. Therefore, the degree of TTS and PTS, if incurred, is 
expected to be minor (low intensity--a few dBs of loss at certain 
frequencies), and the TTS is expected to be brief (minutes to hours) 
before full recovery. No serious injury or mortality is expected as a 
result of the proposed seismic survey, and neither is proposed to be 
authorized.
    Of the nine marine mammal species likely to occur in the proposed 
marine survey area, only the bowhead whale is listed as endangered 
under the ESA. This species is also designated as ``depleted'' under 
the MMPA. Despite these designations, the Bering-Chukchi-Beaufort 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), even in the face 
of ongoing industrial activity and subsistence harvest. There is no 
critical habitat designated in the U.S. Arctic for the bowhead whale. 
Certain stocks or populations of gray and beluga whales and spotted 
seals are listed as endangered or are proposed for listing under the 
ESA; however, none of those stocks or populations occur in the proposed 
activity area. On December 10, 2010, NMFS published a notice of 
proposed threatened status for subspecies of the ringed seal (75 FR 
77476) and a notice of proposed threatened and not warranted status for 
subspecies and distinct population segments of the bearded seal (75 FR 
77496) in the Federal Register. Neither of these two ice seal species 
is currently considered depleted under the MMPA.

Level B Behavioral Harassment

    Most of the bowhead whales encountered during the summer will 
likely show overt disturbance (avoidance) only if they receive airgun 
sounds with levels >=160 dB re 1 [mu] Pa (rms). Odontocete reactions to 
seismic energy 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). Both 
belugas and bowhead whales are expected to occur in much smaller 
numbers in the vicinity of the proposed seismic survey area during the 
proposed survey. In addition, due to the constant movement of the 
seismic survey vessel, the duration of the cetaceans' exposure to noise 
from seismic impulses would be brief. For the same reason, it is 
unlikely that any individual animal would be exposed to high received 
levels multiple times.
    Taking into account the mitigation measures that are planned, 
effects on cetaceans are generally expected to be restricted to 
avoidance of a limited area around the survey operation and short-term 
changes in behavior, falling within the MMPA definition of ``Level B 
harassment,'' with only limited potential occurrences of TTS (Level B 
harassment) and PTS (Level A harassment).
    Furthermore, the estimated numbers of animals potentially exposed 
to sound levels sufficient to cause appreciable disturbance are small 
percentages of the population sizes in the Bering-Chukchi-Beaufort 
seas, as described above.
    Finally, as discussed above, since ION is not likely to start its 
proposed in-ice seismic survey until mid- to late-October when most of 
the cetaceans (especially bowhead whales) have moved out of the area, 
the actual take numbers are expected to be much lower.
    The many reported cases of apparent tolerance by cetaceans from 
seismic exploration, vessel traffic, and some other human activities 
show that co-existence is possible. Mitigation measures such as 
controlled vessel speed, dedicated PSOs, non-pursuit, and shutdowns 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.
    Some individual pinnipeds may be exposed to sound from the proposed 
marine surveys more than once during the time frame of the project. 
However, as discussed previously, due to the constant movement of the 
survey vessel, the probability of an individual pinniped being exposed 
multiple times is much lower than if the source is stationary. 
Therefore, NMFS has determined that the pinnipeds' exposure to sounds 
produced by the proposed marine seismic survey in the Beaufort and 
Chukchi Seas is mostly expected to result in no more than Level B 
harassment and is anticipated to have no more than a negligible impact 
on the animals.
    The estimated Level B behavioral takes proposed to be authorized 
represent up to 12.45% of the Beaufort Sea population of approximately 
39,258 beluga whales (Allen and Angliss, 2010), up to 0.04% of Bering 
Sea stock of approximately 48,215 harbor porpoises, 0.12% of the 
Eastern North Pacific stock of approximately 19,126 gray whales, 1.86% 
of the Bering-Chukchi-Beaufort population of 15,233 individuals 
assuming 3.4 percent annual population growth from the 2001 estimate of 
10,545 animals (Zeh and Punt, 2005), and 1.78% of the Alaska stock of 
approximately 1,233 minke whales. The take estimates presented for 
ringed, bearded, spotted, and ribbon seals represent up to 24.29, 0.04, 
0.04, and 0.04 percent of U.S. Arctic stocks of each species, 
respectively. These estimates represent the percentage of each species 
or stock that could be taken by Level B behavioral harassment if each 
animal is taken only once. Although we have estimated that up to 24.29% 
of ringed seals could be taken as a result of the proposed seismic 
survey activity, it is important to note that the population densities 
for marine mammals within the proposed survey area are overestimates. 
As explained above, because of the lack of fall/winter data, NMFS and 
ION had to rely on the summer/fall density data to calculate expected 
densities of marine mammals and potential take estimates. Our analysis 
has led us to conclude that in the case of ringed seals (and several 
other species), the number of ringed seals that would occur in the 
project area during the proposed survey period is expected to be much 
lower and thus, far fewer ringed seals are actually expected to be 
taken as a result of ION's in-ice seismic survey in the Beaufort Sea. 
Furthermore, it is likely that individual animals could be taken 
multiple times and be counted as different individuals, thus inflating 
the percentage of unique individuals that would be affected. Finally, 
as discussed earlier, the effects to marine mammals that would result 
from Level B behavioral harassment are expected to be minor and brief, 
and mostly involve animals temporarily changing their behavior and 
vacating the proximity of the survey area briefly as the survey vessel 
and icebreaker approach. Marine mammals are expected to resume their 
normal activities and reoccupy the area as soon as the vessels move 
away. Additionally, since the proposed in-ice seismic survey is planned 
outside the breeding season of marine mammals, no impacts on calves or 
pups are expected. Further, there is no known marine

[[Page 65089]]

mammal feeding activity during the period of ION's in-ice seismic 
survey activities. Therefore, any effects to marine mammals are not 
expected to be biologically significant on either the individual or 
population level for thess species. In addition, the mitigation and 
monitoring measures (described previously in this document) included in 
the IHA are expected to further reduce any potential disturbance to 
marine mammals.

Hearing Impairment (TTS, Level B Harassment, or PTS, Level A 
Harassment)

    Most cetaceans (and particularly Arctic cetaceans) show relatively 
high levels of avoidance when received sound pulse levels exceed 160 dB 
re 1 [mu] Pa (rms), and it is uncommon to sight Arctic cetaceans within 
the 180 dB radius, especially for prolonged duration. Results from 
monitoring programs associated with seismic activities in the Arctic 
indicate that cetaceans respond in different ways to sound levels lower 
than 180 dB. These results have been used by agencies to support 
monitoring requirements within distances where received levels fall 
below 160 dB and even 120 dB. Thus, very few animals would be exposed 
to sound levels of 180 dB re 1 [mu] Pa (rms) regardless of 
detectability by PSOs. Avoidance varies among individuals and depends 
on their activities or reasons for being in the area, and occasionally 
a few individual Arctic cetaceans will tolerate sound levels above 160 
dB. Tolerance of levels above 180 dB is infrequent regardless of the 
circumstances, and marine mammals exposed to levels this high are 
expected to avoid the source, thereby minimizing the probability of 
TTS. Therefore, a calculation of the number of cetaceans potentially 
exposed to >180 dB that is based simply on density would be a gross 
overestimate of the actual numbers exposed to 180 dB. Such calculations 
would be misleading unless avoidance response behaviors were taken into 
account to estimate what fraction of those originally present within 
the soon-to-be ensonified to >180 dB zone (as estimated from density) 
would still be there by the time levels reach 180 dB.
    It is estimated that up to 1 bowhead whale and 3 beluga whales 
could be exposed to received noise levels above 180 dB re 1 [mu] Pa 
(rms), and 4 ringed seals could be exposed to received noise levels 
above 190 dB re 1 [mu] Pa (rms) for durations long enough to cause TTS 
if the animals are not detected in time to have mitigation measures 
implemented (or even PTS if such exposures occurred repeatedly). None 
of the other species are expected to be exposed to received sound 
levels anticipated to cause TTS or PTS.
    Marine mammals that are taken by TTS are expected to receive minor 
(in the order of several dBs) and brief (minutes to hours) temporary 
hearing impairment because (1) animals are not likely to remain for 
prolonged periods within high intensity sound fields, and (2) both the 
seismic vessel and the animals are constantly moving, and it is 
unlikely that the animal will be moving along with the vessel during 
the survey. Although repeated experience to TTS could result in PTS 
(Level A harassment), for the same reasons discussed above, even if 
marine mammals experience PTS, the degree of PTS is expected to be 
mild, resulting in a few dB elevation of hearing threshold. Therefore, 
even if a few marine mammals receive TTS or PTS, the degree of these 
effects are expected to be minor and, in the case of TTS, brief, and 
are not expected to be biologically significant for the population or 
species.

Effects on Marine Mammal Habitat

    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 marine survey 
activities, any missed feeding opportunities in the direct project area 
would be minor based on the fact that other feeding areas exist 
elsewhere. For bowhead whales, the majority of the population would 
have migrated past many of the feeding areas of the central Beaufort 
Sea prior to the initiation of activities by ION.
    The effects of icebreaking activity are not expected to result in 
significant modification to marine mammal habitat. Although it is 
expected that the ice coverage would be \8/10\th to \10/10\th, the ice 
in the proposed project area is loose annual ice during the time of the 
proposed in-ice seismic survey activity. Therefore, ice floes being 
broken and pushed aside from the icebreaker are expected to rejoin 
behind the seismic survey path. In addition, no ice seal lairs are 
expected during the period of ION's in-ice seismic survey in the 
Beaufort and Chukchi Seas.
    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 ION's 2012 in-ice seismic survey in the 
Beaufort and Chukchi Seas may result in the incidental take of small 
numbers of marine mammals, by Level A and Level B harassment only, and 
that the 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 ION's 2012 in-ice marine seismic survey in 
the Beaufort and Chukchi Seas 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 ION's CAA and POC. ION has adopted a 
spatial and temporal strategy for its Beaufort and Chukchi Seas in-ice 
seismic survey operation that is intended to avoid subsistence 
activities. ION plans to start its seismic survey after the fall 
bowhead harvests have concluded for the communities of Kaktovik and 
Nuiqsut, and its seismic survey is expected to occur far offshore from 
regular ringed seal hunts. Although hunting may still be occurring in 
Barrow, ION has agreed to work in the eastern part of the survey area 
first so as not to overlap with areas used by hunters in Barrow. The 
late November bowhead harvests on St. Lawrence Island should not be 
affected by ION's vessel transits through the Bering Strait, which 
would not occur until the conclusion of the survey in early to mid-
December. No other subsistence activity is expected to occur during 
ION's proposed seismic survey period.
    Based on the measures described in ION's POC and CAA, the proposed 
mitigation and monitoring measures (described earlier in this 
document), and the project design itself, NMFS has determined there 
will not be an unmitigable adverse impact on subsistence uses from 
ION's icebreaking marine seismic survey in the Beaufort and Chukchi 
Seas.

Endangered Species Act (ESA)

    The bowhead whale is the only marine mammal species currently 
listed as endangered under the ESA that could occur during ION's 
proposed in-ice seismic survey period. In addition, there are two 
marine mammal species that are currently being proposed for listing 
under the ESA with confirmed occurrence in the proposed project area: 
ringed and bearded seals. NMFS'

[[Page 65090]]

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 ION under section 101(a)(5)(D) of the MMPA 
for this activity. A Biological Opinion was issued on October 17, 2012, 
which concludes that issuance of the IHA is not likely to jeopardize 
the continued existence of the ESA-listed marine mammal species and 
species proposed for ESA-listing. 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 ION 
to take marine mammals incidental to conducting in-ice seismic survey 
in the Beaufort and Chukchi Seas during fall/winter 2012. 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 ION 
to take marine mammals incidental to its in-ice seismic survey in the 
Beaufort and Chukchi Seas, Alaska, provided the previously mentioned 
mitigation, monitoring, and reporting requirements are incorporated.

    Dated: October 17, 2012.
Helen M. Golde,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2012-26103 Filed 10-23-12; 8:45 am]
BILLING CODE 3510-22-P