Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey in the Ross Sea, January to February 2015, 68511-68546 [2014-26915]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 79, Number 221 (Monday, November 17, 2014)]
[Notices]
[Pages 68511-68546]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-26915]



[[Page 68511]]

Vol. 79

Monday,

No. 221

November 17, 2014

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; Low-Energy 
Marine Geophysical Survey in the Ross Sea, January to February 2015; 
Notice

Federal Register / Vol. 79 , No. 221 / Monday, November 17, 2014 / 
Notices

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD512


Takes of Marine Mammals Incidental to Specified Activities; Low-
Energy Marine Geophysical Survey in the Ross Sea, January to February 
2015

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

ACTION: Notice; proposed Incidental Harassment Authorization; request 
for comments.

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SUMMARY: NMFS has received an application from the National Science 
Foundation (NSF) Division of Polar Programs, and Antarctic Support 
Contract (ASC) on behalf of Louisiana State University, for an 
Incidental Harassment Authorization (IHA) to take marine mammals, by 
harassment, incidental to conducting a low-energy marine geophysical 
(seismic) survey in the Ross Sea, January to February 2015. Pursuant to 
the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on 
its proposal to issue an IHA to NSF and ASC to incidentally harass, by 
Level B harassment only, 18 species of marine mammals during the 
specified activity.

DATES: Comments and information must be received no later than December 
17, 2014.

ADDRESSES: Comments on the application should be addressed to Jolie 
Harrison, Chief, Permits and Conservation Division, Office of Protected 
Resources, National Marine Fisheries Service, 1315 East-West Highway, 
Silver Spring, MD 20910. The mailbox address for providing email 
comments is ITP.Goldstein@noaa.gov. NMFS is not responsible for email 
comments sent to addresses other than the one provided here. Comments 
sent via email, including all attachments, must not exceed a 25-
megabyte file size.
    Instructions: All comments received are a part of the public record 
and will generally be posted to: https://www.nmfs.noaa.gov/pr/permits/incidental/ without change. All Personal Identifying Information (for 
example, name, address, etc.) voluntarily submitted by the commenter 
may be publicly accessible. Do not submit Confidential Business 
Information or otherwise sensitive or protected information.
    A copy of the IHA application may be obtained by writing to the 
address specified above, telephoning the contact listed here (see FOR 
FURTHER INFORMATION CONTACT) or visiting the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental/. Documents cited in this 
notice may also be viewed by appointment, during regular business 
hours, at the aforementioned address.
    NSF and ASC have prepared a ``Draft Initial Environmental 
Evaluation/Environmental Assessment to Perform Marine Geophysical 
Survey, Collect Bathymetric Measurements, and Conduct Coring by the 
RVIB Nathaniel B. Palmer in the Ross Sea'' (IEE/EA) in accordance with 
the National Environmental Policy Act (NEPA) and the regulations 
published by the Council of Environmental Quality (CEQ). It is posted 
at the foregoing site. NMFS has independently evaluated the IEE/EA and 
has prepared a separate NEPA analysis titled ``Draft Environmental 
Assessment on the Issuance of an Incidental Harassment Authorization to 
the National Science Foundation and Antarctic Support Contract to Take 
Marine Mammals by Harassment Incidental to a Low-Energy Marine 
Geophysical Survey in the Ross Sea, January to April 2015.'' 
Information in the NSF and ASC's IHA application, Draft IEE/EA, Draft 
EA and this notice of the proposed IHA collectively provide the 
environmental information related to proposed issuance of the IHA for 
public review and comment. NMFS will review all comments submitted in 
response to this notice as we complete the NEPA process, including a 
decision of whether to sign a Finding of No Significant Impact (FONSI), 
prior to a final decision on the IHA request.

FOR FURTHER INFORMATION CONTACT: Howard Goldstein or Jolie Harrison, 
Office of Protected Resources, NMFS, 301-427-8401.

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 small numbers of marine 
mammals by United States citizens who engage in a specified activity 
(other than commercial fishing) within a specified geographical region 
if certain findings are made and either regulations are issued or, if 
the taking is limited to harassment, a notice of a proposed 
authorization is provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``. . . an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the United States can apply for an authorization 
to incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) of the MMPA establishes a 45-day time limit for 
NMFS's review of an application, followed by a 30-day public notice and 
comment period on any proposed authorizations for the incidental 
harassment of small numbers of marine mammals. Within 45 days of the 
close of the public comment period, NMFS must either issue or deny the 
authorization.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

Summary of Request

    On July 15, 2014, NMFS received an application from NSF and ASC 
requesting that NMFS issue an IHA for the take, by Level B harassment 
only, of small numbers of marine mammals incidental to conducting a 
low-energy marine seismic survey in International Waters (i.e., high 
seas) in the Ross Sea during January to February 2015. The IHA 
application includes an addendum which includes incidental take 
requests for marine mammals related to icebreaking activities.
    The research would be conducted by Louisiana State University. NSF 
and ASC plan to use one source vessel, the RVIB Nathaniel B. Palmer 
(Palmer), and a seismic airgun array and hydrophone streamer to collect 
seismic data in the Ross Sea. The vessel would be operated by ASC, 
which operates the United

[[Page 68513]]

States Antarctic Program (USAP) under contract with NSF. In support of 
the USAP, NSF and ASC plan to use conventional low-energy, seismic 
methodology to perform marine-based studies in the Ross Sea, including 
evaluation of the timing and duration of two grounding events (i.e., 
advances of grounded ice) to the outer and middle shelf of the Whales 
Deep Basin, a West Antarctic Ice Sheet paleo ice stream trough in the 
eastern Ross Sea (see Figures 1 and 2 of the IHA application). The 
studies would involve a low-energy seismic survey, acquiring core 
samples from the seafloor, and performing radiocarbon dating of benthic 
foraminifera to meet a number of research goals. In addition to the 
proposed operations of the seismic airgun array and hydrophone 
streamer(s), NSF and ASC intend to operate a single-beam echosounder, 
multi-beam echosounder, acoustic Doppler current profiler (ADCP), and 
sub-bottom profiler continuously throughout the survey.
    Acoustic stimuli (i.e., increased underwater sound) generated 
during the operation of the seismic airgun array and from icebreaking 
activities may have the potential to cause behavioral disturbance for 
marine mammals in the proposed survey area. This is the principal means 
of marine mammal taking associated with these activities, and NSF and 
ASC have requested an authorization to take 18 species of marine 
mammals by Level B harassment. Take is not expected to result from the 
use of the single-beam echosounder, multi-beam echosounder, ADCP, and 
sub-bottom profiler, as the brief exposure of marine mammals to one 
pulse, or small numbers of signals, to be generated by these 
instruments in this particular case is not likely to result in the 
harassment of marine mammals. Also, NMFS does not expect take to result 
from collision with the source vessel because it is a single vessel 
moving at a relatively slow, constant cruise speed of 5 knots ([kts]; 
9.3 kilometers per hour [km/hr]; 5.8 miles per hour [mph]) during 
seismic acquisition within the survey, for a relatively short period of 
time (approximately 27 operational days). It is likely that any marine 
mammal would be able to avoid the vessel.

Description of the Proposed Specified Activity

Overview

    NSF and ASC propose to use one source vessel, the Palmer, a two GI 
airgun array and one hydrophone streamer to conduct the conventional 
seismic survey as part of the NSF-funded research project ``Timing and 
Duration of LGM and post-LGM Grounding Events in the Whales Deep Paleo 
Ice Streams, Eastern Ross Sea Continental Shelf.'' In addition to the 
airguns, NSF and ASC intend to conduct a bathymetric survey and core 
sampling from the Palmer during the proposed low-energy seismic survey.

Dates and Duration

    The Palmer is expected to depart from McMurdo Station on 
approximately January 24, 2015 and arrive at Hobart, Australia on 
approximately March 20, 2015. Research operations would be conducted 
over a span of 27 days (from approximately January 24 to February 26, 
2015). At the end of the proposed research operations, the Palmer would 
resume other operational activities, and transit to Hobart, Australia. 
The total distance the Palmer would travel in the region to conduct the 
proposed research activities (i.e., seismic survey, bathymetric survey, 
transit to coring locations and McMurdo Station) represents 
approximately 12,000 km (6,479.5 nmi). Some minor deviation from this 
schedule is possible, depending on logistics and weather (e.g., the 
cruise may depart earlier or be extended due to poor weather; or there 
could be additional days of airgun operations if collected data are 
deemed to be of substandard quality).

Specified Geographic Region

    The proposed project and survey sites are located in selected 
regions of the Ross Sea (located north of the Ross Ice Shelf) and focus 
on the Whales Deep Basin trough (encompassing the region between 76 to 
78[deg] South, and between 165 to 170[deg] West) (see Figure 2 of the 
IHA application). Figure 2 also illustrates the general bathymetry of 
the proposed study area and the previously collected data with respect 
to seismic units and dated cores. The proposed low-energy seismic 
survey would be conducted in International Waters. Figure 2 of the IHA 
application illustrates the general bathymetry of the proposed study 
area near the Ross Ice Shelf. Water depths in the survey area are 
between 100 to 1,000 m. The proposed low-energy seismic survey would be 
within an area of approximately 3,882 km\2\ (1,131.8 nmi\2\). This 
estimate is based on the maximum number of kilometers for the low-
energy seismic survey (1,750 km) multiplied by the area ensonified 
around the planned tracklines (1.109 km x 2). The ensonified area is 
based on the predicted rms radii (m) based on modeling and empirical 
measurements (assuming 100% use of the two 105 in\3\ GI airguns in 100 
to 1,000 m water depths), which was calculated to be 1,109 m (3,638.5 
ft) (see Appendix B of the IHA application).
    If icebreaking is required during the course of the research 
activities in the Antarctica region, it is expected to occur on a 
limited basis. The research activities and associated contingencies are 
designed to avoid areas of heavy sea ice condition, and the Ross Sea 
region is typically clear during the January to February time period 
due to a large polynya which routinely forms in front of the Ross Ice 
Shelf.
    Researchers would work to minimize time spent breaking ice. The 
proposed science operations are more difficult to conduct in icy 
conditions because the ice noise degrades the quality of the 
geophysical and ADCP data. Also, time spent breaking ice takes away 
from time supporting research. Logistically, if the vessel were in 
heavy ice conditions, researchers would not tow the airgun array and 
streamer, as this would likely damage equipment and generate noise 
interference. It is possible that the low-energy seismic survey can be 
performed in low ice conditions if the Palmer could generate an open 
path behind the vessel.
    Because the Palmer is not rated to routinely break multi-year ice, 
operations would generally avoid transiting through older ice (i.e., 2 
years or older, thicker than 1 m). If sea ice is encountered during the 
cruise, it is anticipated the Palmer would proceed primarily through 
one year sea ice, and possibly some new, very thin ice, and would 
follow leads wherever possible. Satellite imagery from the Ross Sea 
region (https://www.iup.physik.uni-bremen.de:8084/ssmis/) documents that 
sea ice is at its minimum extent during the month of February.
    Based on the proposed tracklines, estimated transit to the proposed 
study area from McMurdo Station, and expected ice conditions (using 
historical sea ice extent), it is estimated that the Palmer may need to 
break ice along a distance of approximately 500 km (269.9 nmi) or less. 
Based on the ship's speed of 5 knots under moderate ice conditions, 500 
km represents approximately 54 hours of icebreaking operations. It is 
noted that typical transit through areas of primarily open water 
containing brash or pancake ice are not considered icebreaking for the 
purposes of this assessment.

Detailed Description of the Proposed Specified Activity

    NSF and ASC propose to conduct a low-energy seismic survey in the 
Ross

[[Page 68514]]

Sea from January to February 2015. In addition to the low-energy 
seismic survey, scientific research activities would include conducting 
a bathymetric profile survey of the seafloor using transducer-based 
instruments such as a multi-beam echosounder and sub-bottom profiler; 
acquiring bottom imaging, using underwater camera systems; and 
collecting approximately 32 core samples from the seafloor using 
various methods and equipment. Water depths in the survey area are 100 
to 1,000 meters (m) (328.1 to 3,280.1 feet [ft]). The proposed low-
energy seismic survey is scheduled to occur for a total of 
approximately 200 hours over the course of the entire cruise, which 
would be for approximately 27 operational days in January to February 
2015. The proposed research activities would bisect approximately 
25,500 km\2\ (7,434.6 nmi\2\) in the Ross Sea region (see Figure 2 of 
the IHA application). The proposed low-energy seismic survey would be 
conducted during the day (from nautical twilight-dawn to nautical 
twilight-dusk) and night, and for up to 100 hours of continuous 
operations at a time. Note that there would be 24-hour or near 24-hour 
daylight in the proposed study area between January 24 and February 26, 
2015 (https://www.timeanddate.com/sun/antarctica/mcmurdo?month=2&year=2015). The operation hours and survey length would 
include equipment testing, ramp-up, line changes, and repeat coverage. 
Some minor deviation from these dates would be possible, depending on 
logistics and weather. The Principal Investigator is Dr. Philip Bart of 
the Louisiana State University (Baton Rouge).
    Grounding events in the Whales Deep Basin are represented by 
seismically resolvable Grounding Zone Wedges. During the proposed 
activities in the Ross Sea, researchers would acquire additional 
seismic data and multi-beam bathymetry and imaging to precisely define 
the depositional and erosional limits of the outer and middle shelf 
Grounding Zone Wedges. The proposed collection of benthic samples and 
resulting analyses would test the hypothesis and counter hypothesis 
regarding the West Antarctic Ice Sheet retreat as it relates to the 
Whales Deep Basin paleo ice stream through: (1) Radiocarbon dating in 
situ benthic foraminifera isolated from diamict deposited on the 
Grounding Zone Wedges foreset; (2) ramped pyrolysis of acid insoluble 
organic isolated from diatom ooze overlying Grounding Zone Wedges 
diamict; (3) calculating the duration of the two grounding events; and 
(4) extracting pore-water from the Grounding Zone Wedges diamict to 
determine salinity and [delta]\18\O values to test a numerical model 
prediction regarding the West Antarctic Ice Sheet retreat.
    The procedures to be used for the survey would be similar to those 
used during previous low-energy seismic surveys by NSF and would use 
conventional seismic methodology. The proposed survey would involve one 
source vessel, the Palmer. NSF and ASC would deploy a two Sercel 
Generator Injector (GI) airgun array (each with a discharge volume of 
105 in\3\ [1,720 cm\3\], in one string, with a total volume of 210 
in\3\ [3,441.3 cm\3\]) as an energy source, at a tow depth of up to 3 
to 4 m (9.8 to 13.1 ft) below the surface (more information on the 
airguns can be found in Appendix B of the IHA application). A third 
airgun would serve as a ``hot spare'' to be used as a back-up in the 
event that one of the two operating airguns malfunctions. The airguns 
in the array would be spaced approximately 3 m (9.8 ft) apart and 15 to 
40 m (49.2 to 131.2 ft) astern of the vessel. The receiving system 
would consist of one or two 100 m (328.1 ft) long, 24-channel, solid-
state hydrophone streamer(s) towed behind the vessel. Data acquisition 
is planned along a series of predetermined lines, all of which would be 
in water depths 100 to 1,000 m. As the GI airguns are towed along the 
survey lines, the hydrophone streamer(s) would receive the returning 
acoustic signals and transfer the data to the onboard processing 
system. All planned seismic data acquisition activities would be 
conducted by technicians provided by NSF and ASC, with onboard 
assistance by the scientists who have proposed the study. The vessel 
would be self-contained, and the crew would live aboard the vessel for 
the entire cruise.
    The weather, sea, and ice conditions would be closely monitored, 
including the presence of pack ice that could hinder operation of the 
airgun array and streamer(s) as well as conditions that could limit 
visibility. If situations are encountered which pose a risk to the 
equipment, impede data collection, or require the vessel to stop 
forward progress, the equipment would be shut-down and retrieved until 
conditions improve. In general, the airgun array and streamer(s) could 
be retrieved in less than 30 minutes.
    The planned seismic survey (including equipment testing, start-up, 
line changes, repeat coverage of any areas, and equipment recovery) 
would consist of approximately 1,750 kilometers (km) (944.9 nautical 
miles [nmi]) of transect lines (including turns) in the study area in 
the Ross Sea (see Figures 1 and 2 of the IHA application). In addition 
to the operation of the airgun array, a single-beam and multi-beam 
echosounder, ADCP, and a sub-bottom profiler would also likely be 
operated from the Palmer continuously throughout the cruise. There 
would be additional airgun operations associated with equipment 
testing, ramp-up, and possible line changes or repeat coverage of any 
areas where initial data quality is sub-standard. In NSF and ASC's 
estimated take calculations, 25% has been added for those additional 
operations. The portion of the cruise planned for after the low-energy 
seismic survey in the Ross Sea is not associated with the project; it 
is associated with McMurdo Station support and would occur regardless 
of the low-energy seismic survey (i.e., no science activities would be 
conducted). In addition, the Palmer would transit approximately 3,980 
km (2,149 nmi) to Australia after the planned support activities for 
McMurdo Station.

                     Table 1--Proposed Low-Energy Seismic Survey Activities in the Ross Sea
----------------------------------------------------------------------------------------------------------------
                                    Total                            Time between
      Survey length  (km)          duration   Airgun array total     airgun shots        Streamer length  (m)
                                   (hr) \1\         volume            (distance)
----------------------------------------------------------------------------------------------------------------
1,750 (944.9 nmi)..............         ~200  2 x 105 in\3\ (2 x  5 to 10 seconds    100 (328.1 ft).
                                               1,720 cm\3\).       (12.5 to 25 m or
                                                                   41 to 82 ft).
----------------------------------------------------------------------------------------------------------------
\1\ Airgun operations are planned for no more than 100 continuous hours at a time.


[[Page 68515]]

Vessel Specifications

    The Palmer, a research vessel owned by Edison Chouest Offshore, 
Inc. and operated by NSF and ACS (under a long-term charter with Edison 
Chouest Offshore, Inc.), would tow the two GI airgun array, as well as 
the hydrophone streamer. When the Palmer is towing the airgun array and 
the relatively short hydrophone streamer, the turning rate of the 
vessel while the gear is deployed is approximately 20 degrees per 
minute, which is much higher than the limit of 5 degrees per minute for 
a seismic vessel towing a streamer of more typical length (much greater 
than 1 km [0.5 nmi]). Thus, the maneuverability of the vessel is not 
limited much during operations with the streamer.
    The U.S.-flagged vessel, built in 1992, has a length of 94 m (308.5 
ft); a beam of 18.3 m (60 ft); a maximum draft of 6.8 m (22.5 ft); and 
a gross tonnage of 6,174. The ship is powered by four Caterpillar 3608 
diesel engines (3,300 brake horsepower [hp] at 900 rotations per minute 
[rpm]) and a 1,400 hp flush-mounted, water jet azimuthing bowthruster. 
Electrical power is provided by four Caterpillar 3512, 1,050 kiloWatt 
(kW) diesel generators. The GI airgun compressor onboard the vessel is 
manufactured by Borsig-LMF Seismic Air Compressor. The Palmer's 
operation speed during seismic acquisition is typically approximately 
9.3 km/hr (5 kts) (varying between 7.4 to 11.1 km/hr [4 to 6 kts]). 
When not towing seismic survey gear, the Palmer typically cruises at 
18.7 km/hr (10.1 kts) and has a maximum speed of 26.9 km/hr (14.5 kts). 
The Palmer has an operating range of approximately 27,780 km (15,000 
nmi) (the distance the vessel can travel without refueling), which is 
approximately 70 to 75 days. The vessel can accommodate 37 scientists 
and 22 crew members.
    The vessel also has two locations as likely observation stations 
from which Protected Species Observers (PSO) would watch for marine 
mammals before and during the proposed airgun operations. Observing 
stations would be at the bridge level, with a PSO's eye level 
approximately 16.5 m (54.1 ft) above sea level and an approximately 
270[deg] view around the vessel, and an aloft observation tower that is 
approximately 24.4 m (80.1 ft) above sea level, is protected from the 
weather and has an approximately 360[deg] view around the vessel. More 
details of the Palmer can be found in the IHA application and online 
at: https://www.nsf.gov/geo/plr/support/nathpalm.jsp and https://www.usap.gov/vesselScienceAndOperations/contentHandler.cfm?id=1561

Acoustic Source Specifications--Seismic Airguns

    The Palmer would deploy an airgun array, consisting of two 105 
in\3\ Sercel GI airguns as the primary energy source and a 100 m 
streamer(s) containing hydrophones. The airgun array would have a 
supply firing pressure of 2,000 pounds per square inch (psi) and 2,200 
psi when at high pressure stand-by (i.e., shut-down). The regulator 
would be adjusted to ensure that the maximum pressure to the GI airguns 
is 2,000 psi, but there are times when the GI airguns may be operated 
at pressures as low as 1,750 to 1,800 psi. Seismic pulses for the GI 
airguns would be emitted at intervals of approximately 5 seconds. There 
would be between 360 and 720 shots per hour and the relative linear 
distance between the shots would be between 15 to 30 m (49.2 to 98.4 
ft). During firing, a brief (approximately 0.03 second) pulse sound is 
emitted; the airguns would be silent during the intervening periods. 
The dominant frequency components range from two to 188 Hertz (Hz).
    The GI airguns would fire the compressed air volume in unison in 
harmonic mode. The GI airguns would be used in harmonic mode, that is, 
the volume of the injector chamber (I) of each GI airgun is equal to 
that of its generator chamber (G): 105 in\3\ (1,721 cm\3\) for each 
airgun. The generator chamber of each GI airgun in the primary source 
is the one responsible for introducing the sound pulse into the ocean. 
The injector chamber injects air into the previously-generated bubble 
to maintain its shape, and does not introduce more sound into the 
water. In harmonic mode, the injector volume is designed to 
destructively interfere with the reverberations of the generator 
(source component). Firing the airguns in harmonic mode maximizes 
resolution in the data and minimizes any excess noise in the water 
column or data caused by the reverberations (or bubble pulses). The two 
GI airguns would be spaced approximately 3 m (9.8 ft) apart, side-by-
side, between 15 and 40 m (49.2 and 131.2 ft) behind the Palmer, at a 
depth of up to 3 to 4 m during the low-energy seismic survey.
    The Nucleus modeling software used at Lamont-Doherty Earth 
Observatory of Columbia University (L-DEO) does not include GI airguns 
as part of its airgun library, however signatures and mitigation models 
have been obtained for two 105 in\3\ G airguns that are close 
approximations. A tow depth of 4 m is assumed and would result in the 
largest radii. For the two 105 in\3\ airgun array, the source output 
(downward) is 234.1 dB re 1 [mu]Pam 0-to-peak and 239.8 dB re 1 [mu]Pam 
for peak-to-peak. These numbers were determined applying the 
aforementioned G-airgun approximation to the GI airgun and using 
signatures filtered with DFS V out-256 Hz 72 dB/octave. The dominant 
frequency range would be 20 to 150 Hz for a pair of GI airguns towed at 
4 m depth.
    During the low-energy seismic survey, the vessel would attempt to 
maintain a constant cruise speed of approximately 5 knots. The airguns 
would operate continuously for no more than 100 hours at a time based 
on operational constraints. The total duration of the airgun operations 
would not exceed 200 hours. The relatively short, 24-channel hydrophone 
streamer would provide operational flexibility to allow the low-energy 
seismic survey to proceed along the designated cruise tracklines. The 
design of the seismic equipment is to achieve high-resolution images 
with the ability to correlate to the ultra-high frequency sub-bottom 
profiling data and provide cross-sectional views to pair with the 
seafloor bathymetry.

Metrics Used in This Document

    This section includes a brief explanation of the sound measurements 
frequently used in the discussions of acoustic effects in this 
document. Sound pressure is the sound force per unit area, and is 
usually measured in micropascals ([mu]Pa), where 1 pascal (Pa) is the 
pressure resulting from a force of one newton exerted over an area of 
one square meter. Sound pressure level (SPL) is expressed as the ratio 
of a measured sound pressure and a reference level. The commonly used 
reference pressure level in underwater acoustics is 1 [mu]Pa, and the 
units for SPLs are dB re 1 [mu]Pa. SPL (in decibels [dB]) = 20 log 
(pressure/reference pressure).
    SPL is an instantaneous measurement and can be expressed as the 
peak, the peak-to-peak (p-p), or the root mean square (rms). Root mean 
square, which is the square root of the arithmetic average of the 
squared instantaneous pressure values, is typically used in discussions 
of the effects of sounds on vertebrates and all references to SPL in 
this document refer to the root mean square unless otherwise noted. SPL 
does not take the duration of a sound into account.

Characteristics of the Airgun Pulses

    Airguns function by venting high-pressure air into the water, which 
creates an air bubble. The pressure signature of an individual airgun

[[Page 68516]]

consists of a sharp rise and then fall in pressure, followed by several 
positive and negative pressure excursions caused by the oscillation of 
the resulting air bubble. The oscillation of the air bubble transmits 
sounds downward through the seafloor, and the amount of sound 
transmitted in the near horizontal directions is reduced. However, the 
airgun array also emits sounds that travel horizontally toward non-
target areas.
    The nominal downward-directed source levels of the airgun arrays 
used by NSF and ASC on the Palmer do not represent actual sound levels 
that can be measured at any location in the water. Rather, they 
represent the level that would be found 1 m (3.3 ft) from a 
hypothetical point source emitting the same total amount of sound as is 
emitted by the combined GI airguns. The actual received level at any 
location in the water near the GI airguns would not exceed the source 
level of the strongest individual source. In this case, that would be 
about 228.3 dB re 1 [micro]Pam peak or 234.0 dB re 1 [micro]Pam peak-
to-peak for the two 105 in\3\ airgun array. However, the difference 
between rms and peak or peak-to-peak values for a given pulse depends 
on the frequency content and duration of the pulse, among other 
factors. Actual levels experienced by any organism more than 1 m from 
either GI airgun would be significantly lower.
    Accordingly, L-DEO has predicted and modeled the received sound 
levels in relation to distance and direction from the two GI airgun 
array. A detailed description of L-DEO's modeling for this survey's 
marine seismic source arrays for protected species mitigation is 
provided in the NSF/USGS PEIS. These are the nominal source levels 
applicable to downward propagation. The NSF/USGS PEIS discusses the 
characteristics of the airgun pulses. NMFS refers the reviewers to that 
document for additional information.

Predicted Sound Levels for the Airguns

    To determine buffer and exclusion zones for the airgun array to be 
used, received sound levels have been modeled by L-DEO for a number of 
airgun configurations, including two 105 in\3\ G airguns, in relation 
to distance and direction from the airguns (see Figure 2 in Appendix B 
of the IHA application). The model does not allow for bottom 
interactions, and is most directly applicable to deep water. Because 
the model results are for G airguns, which have more energy than GI 
airguns of the same size, those distances overestimate (by 
approximately 10%) the distances for the two 105 in\3\ GI airguns. 
Although the distances are overestimated, no adjustments for this have 
been made to the radii distances in Table 2 (below). Based on the 
modeling, estimates of the maximum distances from the GI airguns where 
sound levels of 190, 180, and 160 dB re 1 [micro]Pa (rms) are predicted 
to be received in intermediate water are shown in Table 2 (see Table 1 
of Appendix B of the IHA application).
    Empirical data concerning the 190, 180, and 160 dB (rms) distances 
were acquired for various airgun arrays based on measurements during 
the acoustic verification studies conducted by L-DEO in the northern 
Gulf of Mexico (GOM) in 2003 (Tolstoy et al., 2004) and 2007 to 2008 
(Tolstoy et al., 2009; Diebold et al., 2010). Results of the 18 and 36 
airgun array are not relevant for the two GI airguns to be used in the 
proposed low-energy seismic survey because the airgun arrays are not 
the same size or volume. The empirical data for the 6, 10, 12, and 20 
airgun arrays indicate that, for deep water, the L-DEO model tends to 
overestimate the received sound levels at a given distance (Tolstoy et 
al., 2004). For the two G airgun array, measurements were obtained only 
in shallow water. When compared to measurements in acquired in deep 
water, mitigation radii provided by the L-DEO model for the proposed 
airgun operations were found to be conservative. The acoustic 
verification surveys also showed that distances to given received 
levels vary with water depth; these are larger in shallow water, while 
intermediate/slope environments show characteristics intermediate 
between those of shallow water and those of deep water environments, 
and documented the influence of a sloping seafloor. The only 
measurements obtained for intermediate depths during either survey were 
for the 36-airgun array in 2007 to 2008 (Diebold et al., 2010). 
Following results obtained at this site and earlier practice, a 
correction factor of 1.5, irrespective of distance to the airgun array, 
is used to derive intermediate-water radii from modeled deep-water 
radii. Estimates of the maximum distances from the GI airguns where 
sound levels of 160, 180, and 190 dB (rms) are predicted to be received 
in intermediate water are 739, 74, and 24 m (2,424.5, 242.8, 78.7 ft), 
respectively, are obtained from L-DEO's model results in deep water, 
which after multiplication by the correction factor of 1.5 are 1,109, 
111, and 36 m (3,638.5, 364.2, and 118.1 ft) (see Table 1 of Appendix B 
of IHA application)
    Measurements were not made for a two GI airgun array in 
intermediate and deep water; however, NSF and ASC proposes to use the 
buffer and exclusion zones predicted by L-DEO's model for the proposed 
GI airgun operations in intermediate water, although they are likely 
conservative given the empirical results for the other arrays. Using 
the L-DEO model, Table 2 (below) shows the distances at which three rms 
sound levels are expected to be received from the two GI airguns. The 
160 dB re 1 [micro]Pam (rms) is the threshold specified by NMFS for 
potential Level B (behavioral) harassment from impulsive noise for both 
cetaceans and pinnipeds. The 180 and 190 dB re 1 [micro]Pam (rms) 
distances are the safety criteria for potential Level A harassment as 
specified by NMFS (2000) and are applicable to cetaceans and pinnipeds, 
respectively. If marine mammals are detected within or about to enter 
the appropriate exclusion zone, the airguns would be shut-down 
immediately. Table 2 summarizes the predicted distances at which sound 
levels (160, 180, and 190 dB [rms]) are expected to be received from 
the two airgun array (each 105 in\3\) operating in intermediate water 
(100 to 1,000 m [328.1 to 3,280 ft]) depths.

 Table 2--Predicted and Modeled (Two 105 in\3\ GI Airgun Array) Distances to Which Sound Levels =160, 180, and 190 dB re 1 [mu]Pa (rms) Could
                    Be Received in Deep Water During the Proposed Low-Energy Seismic Survey in the Ross Sea, January to February 2015
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Predicted rms radii distances (m) for 2 GI airgun array
    Source and total  volume         Tow depth  (m)       Water depth  (m)  ----------------------------------------------------------------------------
                                                                                      160 dB                    180 dB                    190 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Two GI Airguns (105 in\3\)......  3 to 4..............  Intermediate (100    1,109 (3,638.5 ft)......  111 (364.2 ft)..........  36 (118.1 ft) *100
                                                         to 1,000).                                                               would be used for
                                                                                                                                  pinnipeds as described
                                                                                                                                  in NSF/USGS PEIS*.
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 68517]]

    Based on the NSF/USGS PEIS and Record of Decision, for situations 
which incidental take of marine mammals is anticipated, NSF and ASC 
have proposed exclusion zones of 100 m for cetaceans and pinnipeds for 
all low-energy acoustic sources in water depths greater than 100 m. 
While NMFS views the 100 m exclusion zone for pinnipeds appropriate, 
NMFS has proposed to require an exclusion zone of 111 m for cetaceans 
based on the predicted and modeled values by L-DEO and to be more 
protective for marine mammals.
    NMFS expects that acoustic stimuli resulting from the proposed 
operation of the two GI airgun array has the potential to harass marine 
mammals. NMFS does not expect that the movement of the Palmer, during 
the conduct of the low-energy seismic survey, has the potential to 
harass marine mammals because the relatively slow operation speed of 
the vessel (approximately 5 kts; 9.3 km/hr; 5.8 mph) during seismic 
data acquisition should allow marine mammals to avoid the vessel.

Bathymetric Survey

    Along with the low-energy airgun operations, other additional 
geophysical (detailed swath bathymetry) measurements focused on a 
specific study area within the Ross Sea would be made using hull-
mounted sonar system instruments. The proposed bathymetric research 
would bisect approximately 8,300 km\2\ (2,419.9 nmi\2\) in the Ross Sea 
Region (see Figure 2 of the IHA application). In addition, several 
other transducer-based instruments onboard the vessel would be operated 
continuously during the cruise for operational and navigational 
purposes. During bathymetric survey operations, when the vessel is not 
towing seismic equipment, its average speed would be approximately 10.1 
kts (18.8 km/hr). Operating characteristics for the instruments to be 
used are described below.
    Single-Beam Echosounder (Knudsen 3260)--The hull-mounted CHIRP 
sonar would be operated continuously during all phases of the cruise. 
This instrument is operated at 12 kHz for bottom-tracking purposes or 
at 3.5 kHz in the sub-bottom profiling mode. The sonar emits energy in 
a 30[deg] beam from the bottom of the ship.
    Single-Beam Echosounder (Bathy 2000)--The hull-mounted sonar 
characteristics of the Bathy 2000 are similar to the Knudsen 3260. Only 
one hull-mounted echosounder can be operated at a time, and this source 
would be operated instead of the Knudsen 3260 only if needed (i.e., 
only one would be in continuous operation during the cruise). The 
specific model to be used is expected to be selected by the scientific 
researchers. This was also the preferred instrument for many previous 
low-energy seismic surveys on the Palmer.
    Multi-Beam Sonar (Simrad EM120)--The hull-mounted multi-beam sonar 
would be operated continuously during the cruise. This instrument 
operates at a frequency of 12 kHz, has an estimated maximum source 
energy level of 242 dB re 1[mu]Pa (rms), and emits a very narrow 
(<2[deg]) beam fore to aft and 150[deg] in cross-track. The multi-beam 
system emits a series of nine consecutive 15 ms pulses.
    Acoustic Doppler Current Profiler (ADCP Teledyne RDI VM-150)--The 
hull-mounted ADCP would be operated continuously throughout the cruise. 
The ADCP operates at a frequency of 150 kHz with an estimated acoustic 
output level at the source of 223.6 dB re 1[mu]Pa (rms). Sound energy 
from the ADCP is emitted as a 30[deg] conically-shaped beam.
    Acoustic Doppler Current Profiler (ADCP Ocean Surveyor OS-38)--The 
characteristics of this backup hull-mounted ADCP unit are similar to 
the Teledyne VM-150 and would be continuously operated.
    Acoustic Locator (Pinger)--A pinger would be deployed with certain 
instruments (e.g., camera) and equipment (e.g., corers) so these 
devices can be located in the event they become detached from their 
lines. A pinger typically operates at a frequency of 12 kHz, generates 
a 5 ms pulse per second, and has an acoustical output of 162 dB re 1 
[mu]Pa (rms). A maximum total of 32 coring samples would be obtained 
using these devices and ranging from 1.5 to 3 hours per sample and 
require approximately 62 hours per sample. Therefore, it is estimated 
that the pinger would operate a total of 62 hours.
    Passive Instruments--During the low-energy seismic survey in the 
Ross Sea, underwater imagery would be obtained through deployment of a 
benthos bottom camera and towing benthic camera system (during the 
coring activities). In addition, numerous (approximately 50) expendable 
bathythermograph (XBTs) probes would also be released (and none would 
be recovered) over the course of the cruise to obtain temperature data 
necessary to calculate sound velocity profiles used by the multi-beam 
sonar.

Core Sampling

    The primary sampling goals involve the acquisition of sediment 
cores for analysis. The coring locations would be determined using data 
generated by the low-energy seismic survey.
    It is anticipated that cores would be advanced at a total of 32 
coring locations using several different types of equipment designed to 
meet research specific objectives. Proposed sediment coring activities 
include: box coring at 3 locations, gravity coring at 3 locations, 
jumbo piston coring at 4 locations, Kasten coring at 11 locations, and 
standard piston coring at 11 locations. The proposed coring activities 
are summarized in Table 3 (see below). The small diameter coring 
devices would collect sediment from the seafloor at 32 sample 
locations. At each sampling location up to 176 cm\2\ (27.3 in\2\) of 
seafloor would be disturbed by deployment of the coring devices, 
yielding a cumulative total of approximately 0.6 m\2\ (6.5 ft\2\) 
disturbance during the proposed project (see Figure 2 of the IHA 
application).

                               Table 3--Proposed Coring Activities in the Ross Sea
----------------------------------------------------------------------------------------------------------------
                                                                 Core  diameter    Core length       Number of
                        Sampling device                               (cm)             (m)             cores
----------------------------------------------------------------------------------------------------------------
Box Core (Rectangular Profile)................................             10                0.5               3
Gravity Core..................................................              7.5              3                 3
Jumbo Piston Core.............................................             12.7             12                 4
Kasten Core...................................................             15                6                11
Standard Piston Core..........................................              8.9              9                11
----------------------------------------------------------------------------------------------------------------

    From the sediment cores, the in situ foraminifera and ramped 
pyrolysis radiocarbon data would be used to conduct a detailed 
comparison of acid insoluble organic versus foraminifera radiocarbon 
dates. The grounding-event

[[Page 68518]]

duration data generated would provide a test of the two radiocarbon 
dating strategies. Resolving which of the two interpretations of how 
near-surface sedimentology and stratigraphy of Glomar Challenger Basin 
Grounding Zone Wedges stratigraphy in eastern Ross Sea relates to post-
Last Glacial Maximum grounding-line migration is the goal of the 
proposed research; determining which of the strategies is more accurate 
and/or what offsets exist between the two dating strategies used to 
support these interpretations is important because constraining the 
timing of recent grounding events is essential to predict what factors 
might cause the current stability (i.e., a pause in grounding-line 
migration) to end with additional West Antarctic Ice Sheet retreat.

Icebreaking

    Icebreaking is considered by NMFS to be a continuous sound and NMFS 
estimates that harassment occurs when marine mammals are exposed to 
continuous sounds at a received sound level of 120 dB SPL or above. 
Potential takes of marine mammals may ensue from icebreaking activity 
in which the Palmer is expected to engage in Antarctic waters (i.e., 
along the Ross Sea region, between 76 to 78[deg] South, between 165 to 
170[deg] West). While breaking ice, the noise from the ship, including 
impact with ice, engine noise, and propeller cavitation, would exceed 
120 dB (rms) continuously. If icebreaking does occur in Antarctic 
waters, NMFS, NSF and ASC expect it would occur on a limited basis 
during transit and non-seismic operations to gain access to coring or 
other sampling locations and not during seismic airgun operations. The 
research activities and associated contingencies are designed to avoid 
areas of heavy sea ice condition, and the Ross Sea region is typically 
clear during the January to February time period. If the Palmer breaks 
ice during transit within the Antarctic waters (within the Ross Sea or 
other areas of the Southern Ocean), airgun operations would not be 
conducted concurrently.
    In 2008, acousticians from Scripps Institution of Oceanography 
Marine Physical Laboratory and University of New Hampshire Center for 
Coastal and Ocean Mapping conducted measurements of SPLs of the U.S. 
Coast Guard Cutter (USCGC) Healy icebreaking under various conditions 
(Roth and Schmidt, 2010). The results indicated that the highest mean 
SPL (185 dB) was measured at survey speeds of 4 to 4.5 kts in 
conditions of 5/10 ice and greater. Mean SPL under conditions where the 
ship was breaking heavy ice by backing and ramming was actually lower 
(180 dB). In addition, when backing and ramming, the vessel is 
essentially stationary, so the ensonified area is limited for a short 
period (on the order of minutes to tens of minutes) to the immediate 
vicinity of the vessel until the ship breaks free and once again makes 
headway.
    The 120 dB received sound level radius around the Healy while 
icebreaking was estimated by researchers (USGS, 2010). Using a 
practical spreading model, a source level of 185 dB decays to 120 dB in 
about 21.54 km (11.6 nmi). This model is corroborated by Roth and 
Schmidt (2010). Therefore, as the ship travels through the ice, a swath 
43.08 km (23.3 nmi ft) wide would be subject to sound levels greater 
than or equal to 120 dB. This results in potential exposure of 21, 540 
km\2\ (6,280.1 nmi\2\) to sounds greater than or equal to 120 dB from 
icebreaking.
    Data characterizing the sound levels generated by icebreaking 
activities conducted by the Palmer are not available; therefore, data 
for noise generating from an icebreaking vessel such as the USCGC Healy 
would be used as a proxy. It is noted that the Palmer is a smaller 
vessel and has less icebreaking capability than the U.S. Coast Guard's 
other polar icebreakers, being only capable of breaking ice up to 1 m 
thick at speeds of 3 kts (5.6 km/hr or 3 nmi). Therefore, the sound 
levels that may be generated by the Palmer are expected to be lower 
than the conservative levels estimated and measured for the USCGC 
Healy. Researchers would work to minimize time spent breaking ice as 
science operations are more difficult to conduct in icy conditions 
since the ice noise degrades the quality of the seismic and ADCP data 
and time spent breaking ice takes away from time supporting scientific 
research. Logistically, if the vessel were in heavy ice conditions, 
researchers would not tow the airgun array and streamer, as this would 
likely damage equipment and generate noisy data. It is possible that 
the low-energy seismic survey can be performed in low ice conditions if 
the Palmer could generate an open path behind the vessel.
    Because the Palmer is not rated to break multi-year ice routinely, 
operations generally avoid transiting through older ice (i.e., 2 years 
or older, thicker than 1 m). If sea ice is encountered during the 
cruise, it is anticipated the Palmer would proceed primarily through 
one year sea ice, and possibly some new, very thin ice, and would 
follow leads wherever possible. Based on historical sea ice extent and 
the proposed cruise tracklines, it is estimated by NSF and ASC that the 
Palmer may actively break up ice to a distance of 500 km (270 nmi). 
Based on a ship's speed of 5 kts under moderate ice conditions, this 
distance represents approximately 54 hours of icebreaking operations. 
It is noted that typical transit through areas primarily open water and 
containing brash ice or pancake ice would not be considered 
icebreaking.

Description of the Marine Mammals in the Specified Geographic Area of 
the Proposed Specified Activity

    Various international and national Antarctic research programs 
(e.g., Antarctic Pack Ice Seals Program, Commission for the 
Conservation of Antarctic Marine Living Resources, Japanese Whale 
Research Program under Special Permit in the Antarctic, and NMFS 
National Marine Mammal Laboratory), academic institutions (e.g., 
University of Canterbury, Tokai University, Virginia Institute of 
Marine Sciences, University of Genova), and other organizations (e.g., 
National Institute of Water and Atmospheric Research Ltd., Institute of 
Cetacean Research, Nippon Kaiyo Co., Ltd., H.T. Harvey & Associates, 
Center for Whale Research) have conducted scientific cruises and/or 
examined data on marine mammal sightings along the coast of Antarctica, 
Southern Ocean, and Ross Sea, and these data were considered in 
evaluating potential marine mammals in the proposed action area. 
Records from the International Whaling Commission's International 
Decade of Cetacean Research (IDCR), Southern Ocean Collaboration 
Program (SOC), and Southern Ocean Whale and Ecosystem Research (IWC-
SOWER) circumpolar cruises were also considered.
    The marine mammals that generally occur in the proposed action area 
belong to three taxonomic groups: Mysticetes (baleen whales), 
odontocetes (toothed whales), and pinnipeds (seals and sea lions). The 
marine mammal species that could potentially occur within the Southern 
Ocean in proximity to the proposed action area in the Ross Sea include 
20 species of cetaceans and 7 species of pinnipeds.
    The Ross Sea and surrounding Southern Ocean is a feeding ground for 
a variety of marine mammals. In general, many of the species present in 
the sub-Antarctic study area may be present or migrating through the 
Southern Ocean in the Ross Sea during the proposed low-energy seismic 
survey. Many of the species that may be potentially present in the 
study area

[[Page 68519]]

seasonally migrate to higher latitudes near Antarctica. In general, 
most large whale species (except for the killer whale) migrate north in 
the middle of the austral winter and return to Antarctica in the early 
austral summer.
    The five species of pinnipeds that are found in the Southern Ocean 
and most likely be present in the proposed study area include the 
crabeater (Lebodon carcinophagus), leopard (Hydrurga leptonyx), Ross 
(Ommatophoca rossii), Weddell (Leptonychotes weddellii), and southern 
elephant (Mirounga leonina) seal. Many of these pinniped species breed 
on either the pack ice or subantarctic islands. Crabeater seals are 
more common in the northern regions of the Ross Sea, concentrated in 
the pack ice over the Antarctic Slope Front. Leopard seals are often 
seen during the austral summer off the Adelie penguin (Pygoscelis 
adeliae) rookeries of Ross Island. Ross seals are often found in pack 
ice and open waters, they seem to prefer dense consolidated pack ice 
rather than the open pack ice that is frequented by crabeater seals. 
The Weddell seal is considered to be common and frequently encountered 
in the Ross Sea. Southern elephant seals may enter the Ross Sea in the 
austral summer from breeding and feeding grounds further to the north. 
They are considered uncommon in the Ross Sea. The southern elephant 
seal and Antarctic fur seal have haul-outs and rookeries that are 
located on subantarctic islands and prefer beaches. Antarctic 
(Arctocephalus gazella) and Subantarctic (Arctocephalus tropicalis) fur 
seals preferred habitat is not in the proposed study area, and thus it 
is not considered further in this document.
    Marine mammal species likely to be encountered in the proposed 
study area that are listed as endangered under the U.S. Endangered 
Species Act of 1973 (ESA; 16 U.S.C. 1531 et seq.), includes the 
southern right (Eubalaena australis), humpback (Megaptera 
novaeangliae), sei (Balaenoptera borealis), fin (Balaenoptera 
physalus), blue (Balaenoptera musculus), and sperm (Physeter 
macrocephalus) whale.
    In addition to the 13 species known to occur in the Ross Sea, there 
are 7 cetacean species with ranges that are known to potentially occur 
in the waters of the proposed study area: southern right, Cuvier's 
beaked (Ziphius cavirostris), Gray's beaked (Mesoplodon grayi), 
Hector's beaked (Mesoplodon hectori), and spade-toothed beaked 
(Mesoplodon traversii) whale, southern right whale dolphin 
(Lissodelphis peronii), and spectacled porpoise (Phocoena dioptrica). 
However, these species have not been sighted and are not expected to 
occur where the proposed activities would take place. These species are 
not considered further in this document. Table 4 (below) presents 
information on the habitat, occurrence, distribution, abundance, 
population, and conservation status of the species of marine mammals 
that may occur in the proposed study area during January to February 
2015.

 Table 4--The Habitat, Occurrence, Range, Regional Abundance, and Conservation Status of Marine Mammals That May
                  Occur in or Near the Proposed Low-Energy Seismic Survey Area in the Ross Sea
               [See text and Tables 6 and 7 in NSF and ASC's IHA application for further details]
----------------------------------------------------------------------------------------------------------------
                                                                                Population
           Species                 Habitat      Occurrence       Range           estimate      ESA \1\  MMPA \2\
----------------------------------------------------------------------------------------------------------------
Mysticetes:
    Southern right whale       Coastal,         Rare......  Circumpolar 20   8,000 \3\ to     EN......  D
     (Eubalaena australis).     pelagic.                     to 55[deg]       15,000 \4\.
                                                             South.
    Humpback whale (Megaptera  Pelagic,         Common....  Cosmopolitan...  35,000 to        EN......  D
     novaeangliae).             nearshore                                     40,000 \3\--
                                waters, and                                   Worldwide.
                                banks.                                       9,484 \5\--
                                                                              Scotia Sea and
                                                                              Antarctica
                                                                              Peninsula.
    Minke whale (Balaenoptera  Pelagic and      Common....  Circumpolar--So  NA.............  NL......  NC
     acutorostrata including    coastal.                     uthern
     dwarf sub-species).                                     Hemisphere to
                                                             65[deg] South.
    Antarctic minke whale      Pelagic, ice     Common....  7[deg] South to  Several 100,000  NL......  NC
     (Balaenoptera              floes.                       ice edge         \3\--Worldwide.
     bonaerensis).                                           (usually 20 to  18,125 \5\--
                                                             65[deg] South).  Scotia Sea and
                                                                              Antarctica
                                                                              Peninsula.
    Sei whale (Balaenoptera    Primarily        Uncommon..  Migratory,       80,000 \3\--     EN......  D
     borealis).                 offshore,                    Feeding          Worldwide.
                                pelagic.                     Concentration
                                                             40 to 50[deg]
                                                             South.
    Fin whale (Balaenoptera    Continental      Common....  Cosmopolitan,    140,000 \3\--    EN......  D
     physalus).                 slope, pelagic.              Migratory.       Worldwide.
                                                                             4,672 \5\--
                                                                              Scotia Sea and
                                                                              Antarctica
                                                                              Peninsula.
    Blue whale (Balaenoptera   Pelagic, shelf,  Uncommon..  Migratory Pygmy  8,000 to 9,000   EN......  D
     musculus; including        coastal.                     blue whale--     \3\--Worldwide.
     pygmy blue whale                                        North of        1,700 \6\--
     [Balaenoptera musculus                                  Antarctic        Southern Ocean.
     brevicauda]).                                           Convergence
                                                             55[deg] South.
Odontocetes:
    Sperm whale (Physeter      Pelagic, deep    Common....  Cosmopolitan,    360,000 \3\--    EN......  D
     macrocephalus).            sea.                         Migratory.       Worldwide.
                                                                             9,500 \3\--
                                                                              Antarctic.
    Arnoux's beaked whale      Pelagic........  Common....  Circumpolar in   NA.............  NL......  NC
     (Berardius arnuxii).                                    Southern
                                                             Hemisphere, 24
                                                             to 78[deg]
                                                             South.
    Cuvier's beaked whale      Pelagic........  Rare......  Cosmopolitan...  NA.............  NL......  NC
     (Ziphius cavirostris).
    Southern bottlenose whale  Pelagic........  Common....  Circumpolar--30  500,000 \3\--    NL......  NC
     (Hyperoodon planifrons).                                [deg] South to   South of
                                                             ice edge.        Antarctic
                                                                              Convergence.
    Gray's beaked whale        Pelagic........  Rare......  30[deg] South    NA.............  NL......  NC
     (Mesoplodon grayi).                                     to Antarctic
                                                             waters.
    Hector's beaked whale      Pelagic........  Rare......  Circumpolar--co  NA.............  NL......  NC
     (Mesoplodon hectori).                                   ol temperate
                                                             waters of
                                                             Southern
                                                             Hemisphere.
    Spade-toothed beaked       Pelagic........  Rare......  Circumantarctic  NA.............  NL......  NC
     whale (Mesoplodon
     traversii).
    Strap-toothed beaked       Pelagic........  Common....  30[deg] South    NA.............  NL......  NC
     whale (Mesoplodon                                       to Antarctic
     layardii).                                              Convergence.
    Killer whale (Orcinus      Pelagic, shelf,  Common....  Cosmopolitan...  80,000 \3\--     NL......  NC
     orca).                     coastal, pack                                 South of
                                ice.                                          Antarctic
                                                                              Convergence.
                                                                             25,000 \7\--
                                                                              Southern Ocean.
    Long-finned pilot whale    Pelagic, shelf,  Common....  Circumpolar--19  200,000 \3\      NL......  NC
     (Globicephala melas).      coastal.                     to 68[deg]       \8\--South of
                                                             South in         Antarctic
                                                             Southern         Convergence.
                                                             Hemisphere.

[[Page 68520]]

 
    Southern right whale       Pelagic........  Rare......  12 to 65[deg]    NA.............  NL......  NC
     dolphin (Lissodelphis                                   South.
     peronii).
    Hourglass dolphin          Pelagic, ice     Common....  33[deg] South    144,000 \3\--    NL......  NC
     (Lagenorhynchus            edge.                        to pack ice.     South of
     cruciger).                                                               Antarctic
                                                                              Convergence.
    Spectacled porpoise        Coastal,         Rare......  Circumpolar--So  NA.............  NL......  NC
     (Phocoena dioptrica).      pelagic.                     uthern
                                                             Hemisphere.
Pinnipeds:
    Crabeater seal (Lobodon    Coastal, pack    Common....  Circumpolar--An  5,000,000 to     NL......  NC
     carcinophaga).             ice.                         tarctic.         15,000,000 \3\
                                                                              \9\--Worldwide.
    Leopard seal (Hydrurga     Pack ice, sub-   Common....  Sub-Antarctic    220,000 to       NL......  NC
     leptonyx).                 Antarctic                    islands to       440,000 \3\
                                islands.                     pack ice.        \10\--Worldwid
                                                                              e.
    Ross seal (Ommatophoca     Pack ice,        Common....  Circumpolar--An  130,000 \3\....  NL......  NC
     rossii).                   smooth ice                   tarctic.        20,000 to
                                floes, pelagic.                               220,000 \14\--
                                                                              Worldwide.
    Weddell seal               Fast ice, pack   Common....  Circumpolar--So  500,000 to       NL......  NC
     (Leptonychotes             ice, sub-                    uthern           1,000,000 \3\
     weddellii).                Antarctic                    Hemisphere.      \11\--Worldwid
                                islands.                                      e.
    Southern elephant seal     Coastal,         Uncommon..  Circumpolar--An  640,000 \12\ to  NL......  NC
     (Mirounga leonina).        pelagic, sub-                tarctic          650,000 \3\--
                                Antarctic                    Convergence to   Worldwide.
                                waters.                      pack ice.       470,000--South
                                                                              Georgia Island
                                                                              \14\.
    Antarctic fur seal         Shelf, rocky     Rare......  Sub-Antarctic    1,600,000 \13\   NL......  NC
     (Arctocephalus gazella).   habitats.                    islands to       to 3,000,000
                                                             pack ice edge.   \3\--Worldwide.
    Subantarctic fur seal      Shelf, rocky     Rare......  Subtropical      Greater than     NL......  NC
     (Arctocephalus             habitats.                    front to sub-    310,000 \3\--
     tropicalis).                                            Antarctic        Worldwide.
                                                             islands and
                                                             Antarctica.
----------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ U.S. Endangered Species Act: EN = Endangered, T = Threatened, DL = Delisted, NL = Not listed.
\2\ U.S. Marine Mammal Protection Act: D = Depleted, S = Strategic, NC = Not Classified.
\3\ Jefferson et al., 2008.
\4\ Kenney, 2009.
\5\ Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) survey area (Reilly et al.,
  2004).
\6\ Sears and Perrin, 2009.
\7\ Ford, 2009.
\8\ Olson, 2009.
\9\ Bengston, 2009.
\10\ Rogers, 2009.
\11\ Thomas and Terhune, 2009.
\12\ Hindell and Perrin, 2009.
\13\ Arnould, 2009.
\14\ Academic Press, 2009.

    Refer to sections 3 and 4 of NSF and ASC's IHA application for 
detailed information regarding the abundance and distribution, 
population status, and life history and behavior of these other marine 
mammal species and their occurrence in the proposed action area. The 
IHA application also presents how NSF and ASC calculated the estimated 
densities for the marine mammals in the proposed study area. NMFS has 
reviewed these data and determined them to be the best available 
scientific information for the purposes of the proposed IHA.

Potential Effects of the Proposed Specified Activity on Marine Mammals

    This section includes a summary and discussion of the ways that the 
types of stressors associated with the specified activity (e.g., 
seismic airgun operation, vessel movement, gear deployment, and 
icebreaking) have been observed to impact marine mammals. This 
discussion may also include reactions that we consider to rise to the 
level of a take and those that we do not consider to rise to the level 
of take (for example, with acoustics, we may include a discussion of 
studies that showed animals not reacting at all to sound or exhibiting 
barely measureable avoidance). This section is intended as a background 
of potential effects and does not consider either the specific manner 
in which this activity would be carried out or the mitigation that 
would be implemented, and how either of those would shape the 
anticipated impacts from this specific activity. The ``Estimated Take 
by Incidental Harassment'' section later in this document would include 
a quantitative analysis of the number of individuals that are expected 
to be taken by this activity. The ``Negligible Impact Analysis'' 
section will include the analysis of how this specific activity will 
impact marine mammals and will consider the content of this section, 
the ``Estimated Take by Incidental Harassment'' section, the ``Proposed 
Mitigation'' section, and the ``Anticipated Effects on Marine Mammal 
Habitat'' section to draw conclusions regarding the likely impacts of 
this activity on the reproductive success or survivorship of 
individuals and from that on the affected marine mammal populations or 
stocks.
    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Based 
on available behavioral data, audiograms have been derived using 
auditory evoked potentials, anatomical modeling, and other data, 
Southall et al. (2007) designate ``functional hearing groups'' for 
marine mammals and estimate the lower and upper frequencies of 
functional hearing of the groups. The functional groups and the 
associated frequencies are indicated below (though animals are less 
sensitive to sounds at the outer edge of their functional range and 
most sensitive to sounds of frequencies within a smaller range 
somewhere in the middle of their functional hearing range):

[[Page 68521]]

     Low-frequency cetaceans (13 species of mysticetes): 
Functional hearing is estimated to occur between approximately 7 Hz and 
30 kHz;
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia spp., the franciscana [Pontoporia 
blainvillei], and four species of cephalorhynchids): Functional hearing 
is estimated to occur between approximately 200 Hz and 180 kHz; and
     Phocid pinnipeds in water: Functional hearing is estimated 
to occur between approximately 75 Hz and 100 kHz;
     Otariid pinnipeds in water: Functional hearing is 
estimated to occur between approximately 100 Hz and 40 kHz.
    As mentioned previously in this document, 18 marine mammal species 
(13 cetacean and 5 pinniped species) are likely to occur in the 
proposed low-energy seismic survey area. Of the 13 cetacean species 
likely to occur in NSF and ASC's proposed action area, 6 are classified 
as low-frequency cetaceans (humpback, minke, Antarctic minke, sei, fin, 
and blue whale), and 7 are classified as mid-frequency cetaceans 
(sperm, Arnoux's beaked, southern bottlenose, strap-toothed beaked, 
killer, and long-finned pilot whale, and hourglass dolphin) (Southall 
et al., 2007). Of the 5 pinniped species likely to occur in NSF and 
ASC's proposed action area, all are classified as phocid pinnipeds 
(crabeater, leopard, Ross, Weddell, and southern elephant seal) 
(Southall et al., 2007). A species functional hearing group is a 
consideration when we analyze the effects of exposure to sound on 
marine mammals.
    Acoustic stimuli generated by the operation of the airguns, which 
introduce sound into the marine environment, may have the potential to 
cause Level B harassment of marine mammals in the proposed study area. 
The effects of sounds from airgun operations might include one or more 
of the following: Tolerance, masking of natural sounds, behavioral 
disturbance, temporary or permanent hearing impairment, or non-auditory 
physical or physiological effects (Richardson et al., 1995; Gordon et 
al., 2004; Nowacek et al., 2007; Southall et al., 2007). Permanent 
hearing impairment, in the unlikely event that it occurred, would 
constitute injury, but temporary threshold shift (TTS) is not an injury 
(Southall et al., 2007). Although the possibility cannot be entirely 
excluded, it is unlikely that the proposed project would result in any 
cases of temporary or permanent hearing impairment, or any significant 
non-auditory physical or physiological effects. Based on the available 
data and studies described here, some behavioral disturbance is 
expected. A more comprehensive review of these issues can be found in 
the ``Programmatic Environmental Impact Statement/Overseas 
Environmental Impact Statement prepared for Marine Seismic Research 
that is funded by the National Science Foundation and conducted by the 
U.S. Geological Survey'' (NSF/USGS, 2011) and L-DEO's ``Environmental 
Assessment of a Marine Geophysical Survey by the R/V Marcus G. Langseth 
in the Atlantic Ocean off Cape Hatteras, September to October 2014.''

Tolerance

    Richardson et al. (1995) defines tolerance as the occurrence of 
marine mammals in areas where they are exposed to human activities or 
man-made noise. In many cases, tolerance develops by the animal 
habituating to the stimulus (i.e., the gradual waning of responses to a 
repeated or ongoing stimulus) (Richardson, et al., 1995; Thorpe, 1963), 
but because of ecological or physiological requirements, many marine 
animals may need to remain in areas where they are exposed to chronic 
stimuli (Richardson, et al., 1995).
    Numerous studies have shown that pulsed sounds from airguns are 
often readily detectable in the water at distances of many kilometers. 
Several studies have shown that marine mammals at distances more than a 
few kilometers from operating seismic vessels often show no apparent 
response. That is often true even in cases when the pulsed sounds must 
be readily audible to the animals based on measured received levels and 
the hearing sensitivity of the marine mammal group. Although various 
baleen whales and toothed whales, and (less frequently) pinnipeds have 
been shown to react behaviorally to airgun pulses under some 
conditions, at other times marine mammals of all three types have shown 
no overt reactions. The relative responsiveness of baleen and toothed 
whales are quite variable.

Masking

    The term masking refers to the inability of a subject to recognize 
the occurrence of an acoustic stimulus as a result of the interference 
of another acoustic stimulus (Clark et al., 2009). Introduced 
underwater sound may, through masking, reduce the effective 
communication distance of a marine mammal species if the frequency of 
the source is close to that used as a signal by the marine mammal, and 
if the anthropogenic sound is present for a significant fraction of the 
time (Richardson et al., 1995).
    The airguns for the proposed low-energy seismic survey have 
dominant frequency components of 2 to 188 Hz. This frequency range 
fully overlaps the lower part of the frequency range of odontocete 
calls and/or functional hearing (full range about 150 Hz to 180 kHz). 
Airguns also produce a small portion of their sound at mid and high 
frequencies that overlap most, if not all, frequencies produced by 
odontocetes. While it is assumed that mysticetes can detect acoustic 
impulses from airguns and vessel sounds (Richardson et al., 1995a), 
sub-bottom profilers, and most of the multi-beam echosounders would 
likely be detectable by some mysticetes based on presumed mysticete 
hearing sensitivity. Odontocetes are presumably more sensitive to mid 
to high frequencies produced by the multi-beam echosounders and sub-
bottom profilers than to the dominant low frequencies produced by the 
airguns and vessel. A more comprehensive review of the relevant 
background information for odontocetes appears in Section 3.6.4.3, 
Section 3.7.4.3 and Appendix E of the NSF/USGS PEIS (2011).
    Masking effects of pulsed sounds (even from large arrays of 
airguns) on marine mammal calls and other natural sounds are expected 
to be limited. Because of the intermittent nature and low duty cycle of 
seismic airgun pulses, animals can emit and receive sounds in the 
relatively quiet intervals between pulses. However, in some situations, 
reverberation occurs for much or the entire interval between pulses 
(e.g., Simard et al., 2005; Clark and Gagnon, 2006) which could mask 
calls. Some baleen and toothed whales are known to continue calling in 
the presence of seismic pulses, and their calls can usually be heard 
between the seismic pulses (e.g., Richardson et al., 1986; McDonald et 
al., 1995; Greene et al., 1999; Nieukirk et al., 2004; Smultea et al., 
2004; Holst et al., 2005a,b, 2006; and Dunn and Hernandez, 2009). 
However, Clark and Gagnon (2006) reported that fin whales in the North 
Atlantic Ocean went silent for an extended period starting soon after 
the onset of a seismic survey in the area. Similarly, there has been 
one report that sperm whales ceased calling when exposed to pulses from 
a very distant seismic ship (Bowles

[[Page 68522]]

et al., 1994). However, more recent studies found that they continued 
calling in the presence of seismic pulses (Madsen et al., 2002; Tyack 
et al., 2003; Smultea et al., 2004; Holst et al., 2006; and Jochens et 
al., 2008). Dilorio and Clark (2009) found evidence of increased 
calling by blue whales during operations by a lower-energy seismic 
source (i.e., sparker). Dolphins and porpoises commonly are heard 
calling while airguns are operating (e.g., Gordon et al., 2004; Smultea 
et al., 2004; Holst et al., 2005a, b; and Potter et al., 2007). The 
sounds important to small odontocetes are predominantly at much higher 
frequencies than are the dominant components of airgun sounds, thus 
limiting the potential for masking.
    Pinnipeds have the most sensitive hearing and/or produce most of 
their sounds in frequencies higher than the dominant components of 
airgun sound, but there is some overlap in the frequencies of the 
airgun pulses and the calls. However, the intermittent nature of airgun 
pules presumably reduces the potential for masking.
    Marine mammals are thought to be able to compensate for masking by 
adjusting their acoustic behavior through shifting call frequencies, 
increasing call volume, and increasing vocalization rates. For example 
blue whales are found to increase call rates when exposed to noise from 
seismic surveys in the St. Lawrence Estuary (Dilorio and Clark, 2009). 
The North Atlantic right whales (Eubalaena glacialis) exposed to high 
shipping noise increased call frequency (Parks et al., 2007), while 
some humpback whales respond to low-frequency active sonar playbacks by 
increasing song length (Miller et al., 2000). In general, NMFS expects 
the masking effects of seismic pulses to be minor, given the normally 
intermittent nature of seismic pulses.

Behavioral Disturbance

    Marine mammals may behaviorally react to sound when exposed to 
anthropogenic noise. Disturbance includes a variety of effects, 
including subtle to conspicuous changes in behavior, movement, and 
displacement. Reactions to sound, if any, depend on species, state of 
maturity, experience, current activity, reproductive state, time of 
day, and many other factors (Richardson et al., 1995; Wartzok et al., 
2004; Southall et al., 2007; Weilgart, 2007). These behavioral 
reactions are often shown as: Changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where noise sources are located; and/or 
flight responses (e.g., pinnipeds flushing into the water from haul-
outs or rookeries). If a marine mammal does react briefly to an 
underwater sound by changing its behavior or moving a small distance, 
the impacts of the change are unlikely to be significant to the 
individual, let alone the stock or population. However, if a sound 
source displaces marine mammals from an important feeding or breeding 
area for a prolonged period, impacts on individuals and populations 
could be significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, and/or reproduction. Some of these 
significant behavioral modifications include:
     Change in diving/surfacing patterns (such as those thought 
to be causing beaked whale stranding due to exposure to military mid-
frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cessation of feeding or social interaction.
    The onset of behavioral disturbance from anthropogenic noise 
depends on both external factors (characteristics of noise sources and 
their paths) and the receiving animals (hearing, motivation, 
experience, demography) and is also difficult to predict (Richardson et 
al., 1995; Southall et al., 2007). Given the many uncertainties in 
predicting the quantity and types of impacts of noise on marine 
mammals, it is common practice to estimate how many mammals would be 
present within a particular distance of industrial activities and/or 
exposed to a particular level of sound. In most cases, this approach 
likely overestimates the numbers of marine mammals that would be 
affected in some biologically-important manner.
    Baleen Whales--Baleen whales generally tend to avoid operating 
airguns, but avoidance radii are quite variable (reviewed in Richardson 
et al., 1995; Gordon et al., 2004). Whales are often reported to show 
no overt reactions to pulses from large arrays of airguns at distances 
beyond a few kilometers, even though the airgun pulses remain well 
above ambient noise levels out to much longer distances. However, 
baleen whales exposed to strong noise pulses from airguns often react 
by deviating from their normal migration route and/or interrupting 
their feeding and moving away. In the cases of migrating gray 
(Eschrichtius robustus) and bowhead (Balaena mysticetus) whales, the 
observed changes in behavior appeared to be of little or no biological 
consequence to the animals (Richardson, et al., 1995). They simply 
avoided the sound source by displacing their migration route to varying 
degrees, but within the natural boundaries of the migration corridors.
    Studies of gray, bowhead, and humpback whales have shown that 
seismic pulses with received levels of 160 to 170 dB re 1 [mu]Pa (rms) 
seem to cause obvious avoidance behavior in a substantial fraction of 
the animals exposed (Malme et al., 1986, 1988; Richardson et al., 
1995). In many areas, seismic pulses from large arrays of airguns 
diminish to those levels at distances ranging from 4 to 15 km (2.2 to 
8.1 nmi) from the source. A substantial proportion of the baleen whales 
within those distances may show avoidance or other strong behavioral 
reactions to the airgun array. Subtle behavioral changes sometimes 
become evident at somewhat lower received levels, and studies have 
shown that some species of baleen whales, notably bowhead, gray, and 
humpback whales, at times, show strong avoidance at received levels 
lower than 160 to 170 dB re 1 [mu]Pa (rms).
    Researchers have studied the responses of humpback whales to 
seismic surveys during migration, feeding during the summer months, 
breeding while offshore from Angola, and wintering offshore from 
Brazil. McCauley et al. (1998, 2000a) studied the responses of humpback 
whales off western Australia to a full-scale seismic survey with a 16 
airgun array (2,678 in\3\) and to a single airgun (20 in\3\) with 
source level of 227 dB re 1 [micro]Pa (p-p). In the 1998 study, they 
documented that avoidance reactions began at 5 to 8 km (2.7 to 4.3 nmi) 
from the array, and that those reactions kept most pods approximately 3 
to 4 km (1.6 to 2.2 nmi) from the operating seismic boat. In the 2000 
study, they noted localized displacement during migration of 4 to 5 km 
(2.2 to 2.7 nmi) by traveling pods and 7 to 12 km (3.8 to 6.5 nmi) by 
more sensitive resting pods of cow-calf pairs. Avoidance distances with 
respect to the single airgun were smaller but consistent with the 
results from the full array in terms of the received sound levels. The 
mean received level for initial avoidance of an approaching

[[Page 68523]]

airgun was 140 dB re 1 [mu]Pa (rms) for humpback pods containing 
females, and at the mean closest point of approach distance the 
received level was 143 dB re 1 [mu]Pa (rms). The initial avoidance 
response generally occurred at distances of 5 to 8 km (2.7 to 4.3 nmi) 
from the airgun array and 2 km (1.1 nmi) from the single airgun. 
However, some individual humpback whales, especially males, approached 
within distances of 100 to 400 m (328 to 1,312 ft), where the maximum 
received level was 179 dB re 1 [mu]Pa (rms).
    Data collected by observers during several seismic surveys in the 
Northwest Atlantic showed that sighting rates of humpback whales were 
significantly greater during non-seismic periods compared with periods 
when a full array was operating (Moulton and Holst, 2010). In addition, 
humpback whales were more likely to swim away and less likely to swim 
towards a vessel during seismic vs. non-seismic periods (Moulton and 
Holst, 2010).
    Humpback whales on their summer feeding grounds in southeast Alaska 
did not exhibit persistent avoidance when exposed to seismic pulses 
from a 1.64-L (100 in\3\) airgun (Malme et al., 1985). Some humpbacks 
seemed ``startled'' at received levels of 150 to 169 dB re 1 [mu]Pa. 
Malme et al. (1985) concluded that there was no clear evidence of 
avoidance, despite the possibility of subtle effects, at received 
levels up to 172 dB re 1 [mu]Pa (rms). However, Moulton and Holst 
(2010) reported that humpback whales monitored during seismic surveys 
in the Northwest Atlantic had lower sighting rates and were most often 
seen swimming away from the vessel during seismic periods compared with 
periods when airguns were silent.
    Studies have suggested that South Atlantic humpback whales 
wintering off Brazil may be displaced or even strand upon exposure to 
seismic surveys (Engel et al., 2004). The evidence for this was 
circumstantial and subject to alternative explanations (IAGC, 2004). 
Also, the evidence was not consistent with subsequent results from the 
same area of Brazil (Parente et al., 2006), or with direct studies of 
humpbacks exposed to seismic surveys in other areas and seasons. After 
allowance for data from subsequent years, there was ``no observable 
direct correlation'' between strandings and seismic surveys (IWC, 2007: 
236).
    Reactions of migrating and feeding (but not wintering) gray whales 
to seismic surveys have been studied. Malme et al. (1986, 1988) studied 
the responses of feeding eastern Pacific gray whales to pulses from a 
single 100 in\3\ airgun off St. Lawrence Island in the northern Bering 
Sea. They estimated, based on small sample sizes, that 50 percent of 
feeding gray whales stopped feeding at an average received pressure 
level of 173 dB re 1 [mu]Pa on an (approximate) rms basis, and that 10 
percent of feeding whales interrupted feeding at received levels of 163 
dB re 1 [micro]Pa (rms). Those findings were generally consistent with 
the results of experiments conducted on larger numbers of gray whales 
that were migrating along the California coast (Malme et al., 1984; 
Malme and Miles, 1985), and western Pacific gray whales feeding off 
Sakhalin Island, Russia (Wursig et al., 1999; Gailey et al., 2007; 
Johnson et al., 2007; Yazvenko et al., 2007a, b), along with data on 
gray whales off British Columbia (Bain and Williams, 2006).
    Various species of Balaenoptera (blue, sei, fin, and minke whales) 
have occasionally been seen in areas ensonified by airgun pulses 
(Stone, 2003; MacLean and Haley, 2004; Stone and Tasker, 2006), and 
calls from blue and fin whales have been localized in areas with airgun 
operations (e.g., McDonald et al., 1995; Dunn and Hernandez, 2009; 
Castellote et al., 2010). Sightings by observers on seismic vessels off 
the United Kingdom from 1997 to 2000 suggest that, during times of good 
sightability, sighting rates for mysticetes (mainly fin and sei whales) 
were similar when large arrays of airguns were shooting versus silent 
(Stone, 2003; Stone and Tasker, 2006). However, these whales tended to 
exhibit localized avoidance, remaining significantly further (on 
average) from the airgun array during seismic operations compared with 
non-seismic periods (Stone and Tasker, 2006). Castellote et al. (2010) 
reported that singing fin whales in the Mediterranean moved away from 
an operating airgun array.
    Ship-based monitoring studies of baleen whales (including blue, 
fin, sei, minke, and humpback whales) in the Northwest Atlantic found 
that overall, this group had lower sighting rates during seismic vs. 
non-seismic periods (Moulton and Holst, 2010). Baleen whales as a group 
were also seen significantly farther from the vessel during seismic 
compared with non-seismic periods, and they were more often seen to be 
swimming away from the operating seismic vessel (Moulton and Holst, 
2010). Blue and minke whales were initially sighted significantly 
farther from the vessel during seismic operations compared to non-
seismic periods; the same trend was observed for fin whales (Moulton 
and Holst, 2010). Minke whales were most often observed to be swimming 
away from the vessel when seismic operations were underway (Moulton and 
Holst, 2010).
    Data on short-term reactions by cetaceans to impulsive noises are 
not necessarily indicative of long-term or biologically significant 
effects. It is not known whether impulsive sounds affect reproductive 
rate or distribution and habitat use in subsequent days or years. 
However, gray whales have continued to migrate annually along the west 
coast of North America with substantial increases in the population 
over recent years, despite intermittent seismic exploration (and much 
ship traffic) in that area for decades (Appendix A in Malme et al., 
1984; Richardson et al., 1995; Allen and Angliss, 2010). The western 
Pacific gray whale population did not seem affected by a seismic survey 
in its feeding ground during a previous year (Johnson et al., 2007). 
Similarly, bowhead whales have continued to travel to the eastern 
Beaufort Sea each summer, and their numbers have increased notably, 
despite seismic exploration in their summer and autumn range for many 
years (Richardson et al., 1987; Allen and Angliss, 2010). The history 
of coexistence between seismic surveys and baleen whales suggests that 
brief exposures to sound pulses from any single seismic survey are 
unlikely to result in prolonged effects.
    Toothed Whales--Little systematic information is available about 
reactions of toothed whales to noise pulses. Few studies similar to the 
more extensive baleen whale/seismic pulse work summarized above have 
been reported for toothed whales. However, there are recent systematic 
studies on sperm whales (e.g., Gordon et al., 2006; Madsen et al., 
2006; Winsor and Mate, 2006; Jochens et al., 2008; Miller et al., 
2009). There is an increasing amount of information about responses of 
various odontocetes to seismic surveys based on monitoring studies 
(e.g., Stone, 2003; Smultea et al., 2004; Moulton and Miller, 2005; 
Bain and Williams, 2006; Holst et al., 2006; Stone and Tasker, 2006; 
Potter et al., 2007; Hauser et al., 2008; Holst and Smultea, 2008; 
Weir, 2008; Barkaszi et al., 2009; Richardson et al., 2009; Moulton and 
Holst, 2010).
    Seismic operators and PSOs on seismic vessels regularly see 
dolphins and other small toothed whales near operating airgun arrays, 
but in general there is a tendency for most delphinids to show some 
avoidance of operating seismic vessels (e.g., Goold, 1996a,b,c; 
Calambokidis and Osmek, 1998; Stone, 2003; Moulton and Miller, 2005; 
Holst

[[Page 68524]]

et al., 2006; Stone and Tasker, 2006; Weir, 2008; Richardson et al., 
2009; Barkaszi et al., 2009; Moulton and Holst, 2010). Some dolphins 
seem to be attracted to the seismic vessel and floats, and some ride 
the bow wave of the seismic vessel even when large arrays of airguns 
are firing (e.g., Moulton and Miller, 2005). Nonetheless, small toothed 
whales more often tend to head away, or to maintain a somewhat greater 
distance from the vessel, when a large array of airguns is operating 
than when it is silent (e.g., Stone and Tasker, 2006; Weir, 2008; Barry 
et al., 2010; Moulton and Holst, 2010). In most cases, the avoidance 
radii for delphinids appear to be small, on the order of one km or 
less, and some individuals show no apparent avoidance. Captive 
bottlenose dolphins (Tursiops truncatus) and beluga whales 
(Delphinapterus leucas) exhibited changes in behavior when exposed to 
strong pulsed sounds similar in duration to those typically used in 
seismic surveys (Finneran et al., 2000, 2002, 2005). However, the 
animals tolerated high received levels of sound before exhibiting 
aversive behaviors.
    Results of porpoises depend on species. The limited available data 
suggest that harbor porpoises (Phocoena phocoena) show stronger 
avoidance of seismic operations than do Dall's porpoises (Phocoenoides 
dalli) (Stone, 2003; MacLean and Koski, 2005; Bain and Williams, 2006; 
Stone and Tasker, 2006). Dall's porpoises seem relatively tolerant of 
airgun operations (MacLean and Koski, 2005; Bain and Williams, 2006), 
although they too have been observed to avoid large arrays of operating 
airguns (Calambokidis and Osmek, 1998; Bain and Williams, 2006). This 
apparent difference in responsiveness of these two porpoise species is 
consistent with their relative responsiveness to boat traffic and some 
other acoustic sources (Richardson et al., 1995; Southall et al., 
2007).
    Most studies of sperm whales exposed to airgun sounds indicate that 
the sperm whale shows considerable tolerance of airgun pulses (e.g., 
Stone, 2003; Moulton et al., 2005, 2006a; Stone and Tasker, 2006; Weir, 
2008). In most cases the whales do not show strong avoidance, and they 
continue to call. However, controlled exposure experiments in the Gulf 
of Mexico indicate that foraging behavior was altered upon exposure to 
airgun sound (Jochens et al., 2008; Miller et al., 2009; Tyack, 2009). 
There are almost no specific data on the behavioral reactions of beaked 
whales to seismic surveys. However, some northern bottlenose whales 
(Hyperoodon ampullatus) remained in the general area and continued to 
produce high-frequency clicks when exposed to sound pulses from distant 
seismic surveys (Gosselin and Lawson, 2004; Laurinolli and Cochrane, 
2005; Simard et al., 2005). Most beaked whales tend to avoid 
approaching vessels of other types (e.g., Wursig et al., 1998). They 
may also dive for an extended period when approached by a vessel (e.g., 
Kasuya, 1986), although it is uncertain how much longer such dives may 
be as compared to dives by undisturbed beaked whales, which also are 
often quite long (Baird et al., 2006; Tyack et al., 2006). Based on a 
single observation, Aguilar-Soto et al. (2006) suggested that foraging 
efficiency of Cuvier's beaked whales may be reduced by close approach 
of vessels. In any event, it is likely that most beaked whales would 
also show strong avoidance of an approaching seismic vessel, although 
this has not been documented explicitly. In fact, Moulton and Holst 
(2010) reported 15 sightings of beaked whales during seismic studies in 
the Northwest Atlantic; seven of those sightings were made at times 
when at least one airgun was operating. There was little evidence to 
indicate that beaked whale behavior was affected by airgun operations; 
sighting rates and distances were similar during seismic and non-
seismic periods (Moulton and Holst, 2010).
    There are increasing indications that some beaked whales tend to 
strand when naval exercises involving mid-frequency sonar operation are 
ongoing nearby (e.g., Simmonds and Lopez-Jurado, 1991; Frantzis, 1998; 
NOAA and USN, 2001; Jepson et al., 2003; Hildebrand, 2005; Barlow and 
Gisiner, 2006; see also the ``Stranding and Mortality'' section in this 
notice). These strandings are apparently a disturbance response, 
although auditory or other injuries or other physiological effects may 
also be involved. Whether beaked whales would ever react similarly to 
seismic surveys is unknown. Seismic survey sounds are quite different 
from those of the sonar in operation during the above-cited incidents.
    Odontocete reactions to large arrays of airguns are variable and, 
at least for delphinids, seem to be confined to a smaller radius than 
has been observed for the more responsive of some mysticetes. However, 
other data suggest that some odontocete species, including harbor 
porpoises, may be more responsive than might be expected given their 
poor low-frequency hearing. Reactions at longer distances may be 
particularly likely when sound propagation conditions are conducive to 
transmission of the higher frequency components of airgun sound to the 
animals' location (DeRuiter et al., 2006; Goold and Coates, 2006; Tyack 
et al., 2006; Potter et al., 2007).
    Pinnipeds--Pinnipeds are not likely to show a strong avoidance 
reaction to the airgun array. Visual monitoring from seismic vessels 
has shown only slight (if any) avoidance of airguns by pinnipeds, and 
only slight (if any) changes in behavior. In the Beaufort Sea, some 
ringed seals avoided an area of 100 m to (at most) a few hundred meters 
around seismic vessels, but many seals remained within 100 to 200 m 
(328 to 656 ft) of the trackline as the operating airgun array passed 
by (e.g., Harris et al., 2001; Moulton and Lawson, 2002; Miller et al., 
2005.). Ringed seal (Pusa hispida) sightings averaged somewhat farther 
away from the seismic vessel when the airguns were operating than when 
they were not, but the difference was small (Moulton and Lawson, 2002). 
Similarly, in Puget Sound, sighting distances for harbor seals (Phoca 
vitulina) and California sea lions (Zalophus californianus) tended to 
be larger when airguns were operating (Calambokidis and Osmek, 1998). 
Previous telemetry work suggests that avoidance and other behavioral 
reactions may be stronger than evident to date from visual studies 
(Thompson et al., 1998).
    During seismic exploration off Nova Scotia, gray seals (Halichoerus 
grypus) exposed to noise from airguns and linear explosive charges did 
not react strongly (J. Parsons in Greene et al., 1985). Pinnipeds in 
both water and air, sometimes tolerate strong noise pulses from non-
explosive and explosive scaring devices, especially if attracted to the 
area for feeding and reproduction (Mate and Harvey, 1987; Reeves et 
al., 1996). Thus pinnipeds are expected to be rather tolerant of, or 
habituate to, repeated underwater sounds from distant seismic sources, 
at least when the animals are strongly attracted to the area.

Hearing Impairment and Other Physical Effects

    Exposure to high intensity sound for a sufficient duration may 
result in auditory effects such as a noise-induced threshold shift--an 
increase in the auditory threshold after exposure to noise (Finneran, 
Carder, Schlundt, and Ridgway, 2005). Factors that influence the amount 
of threshold shift include the amplitude, duration, frequency content, 
temporal pattern, and energy distribution of noise exposure. The 
magnitude of hearing threshold shift normally decreases over time 
following

[[Page 68525]]

cessation of the noise exposure. The amount of threshold shift just 
after exposure is called the initial threshold shift. If the threshold 
shift eventually returns to zero (i.e., the threshold returns to the 
pre-exposure value), it is called temporary threshold shift (TTS) 
(Southall et al., 2007). Researchers have studied TTS in certain 
captive odontocetes and pinnipeds exposed to strong sounds (reviewed in 
Southall et al., 2007). However, there has been no specific 
documentation of TTS let alone permanent hearing damage, i.e., 
permanent threshold shift (PTS), in free-ranging marine mammals exposed 
to sequences of airgun pulses during realistic field conditions.
    Temporary Threshold Shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to a strong sound (Kryter, 
1985). While experiencing TTS, the hearing threshold rises and a sound 
must be stronger in order to be heard. At least in terrestrial mammals, 
TTS can last from minutes or hours to (in cases of strong TTS) days. 
For sound exposures at or somewhat above the TTS threshold, hearing 
sensitivity in both terrestrial and marine mammals recovers rapidly 
after exposure to the noise ends. Few data on sound levels and 
durations necessary to elicit mild TTS have been obtained for marine 
mammals, and none of the published data concern TTS elicited by 
exposure to multiple pulses of sound. Available data on TTS in marine 
mammals are summarized in Southall et al. (2007). Table 2 (above) 
presents the estimated distances from the Palmer's airguns at which the 
received energy level (per pulse, flat-weighted) would be expected to 
be greater than or equal to 180 and 190 dB re 1 [micro]Pa (rms).
    To avoid the potential for injury, NMFS (1995, 2000) concluded that 
cetaceans and pinnipeds should not be exposed to pulsed underwater 
noise at received levels exceeding 180 and 190 dB re 1 [mu]Pa (rms). 
NMFS believes that to avoid the potential for Level A harassment, 
cetaceans and pinnipeds should not be exposed to pulsed underwater 
noise at received levels exceeding 180 and 190 dB re 1 [mu]Pa (rms), 
respectively. The established 180 and 190 dB (rms) criteria are not 
considered to be the levels above which TTS might occur. Rather, they 
are the received levels above which, in the view of a panel of 
bioacoustics specialists convened by NMFS before TTS measurements for 
marine mammals started to become available, one could not be certain 
that there would be no injurious effects, auditory or otherwise, to 
marine mammals. NMFS also assumes that cetaceans and pinnipeds exposed 
to levels exceeding 160 dB re 1 [mu]Pa (rms) may experience Level B 
harassment.
    For toothed whales, researchers have derived TTS information for 
odontocetes from studies on the bottlenose dolphin and beluga. The 
experiments show that exposure to a single impulse at a received level 
of 207 kPa (or 30 psi, p-p), which is equivalent to 228 dB re 1 Pa (p-
p), resulted in a 7 and 6 dB TTS in the beluga whale at 0.4 and 30 kHz, 
respectively. Thresholds returned to within 2 dB of the pre-exposure 
level within 4 minutes of the exposure (Finneran et al., 2002). For the 
one harbor porpoise tested, the received level of airgun sound that 
elicited onset of TTS was lower (Lucke et al., 2009). If these results 
from a single animal are representative, it is inappropriate to assume 
that onset of TTS occurs at similar received levels in all odontocetes 
(cf. Southall et al., 2007). Some cetaceans apparently can incur TTS at 
considerably lower sound exposures than are necessary to elicit TTS in 
the beluga or bottlenose dolphin.
    For baleen whales, there are no data, direct or indirect, on levels 
or properties of sound that are required to induce TTS. The frequencies 
to which baleen whales are most sensitive are assumed to be lower than 
those to which odontocetes are most sensitive, and natural background 
noise levels at those low frequencies tend to be higher. As a result, 
auditory thresholds of baleen whales within their frequency band of 
best hearing are believed to be higher (less sensitive) than are those 
of odontocetes at their best frequencies (Clark and Ellison, 2004). 
From this, it is suspected that received levels causing TTS onset may 
also be higher in baleen whales than those of odontocetes (Southall et 
al., 2007).
    In pinnipeds, researchers have not measured TTS thresholds 
associated with exposure to brief pulses (single or multiple) of 
underwater sound. Initial evidence from more prolonged (non-pulse) 
exposures suggested that some pinnipeds (harbor seals in particular) 
incur TTS at somewhat lower received levels than do small odontocetes 
exposed for similar durations (Kastak et al., 1999, 2005; Ketten et 
al., 2001). The TTS threshold for pulsed sounds has been indirectly 
estimated as being an SEL of approximately 171 dB re 1 
[micro]Pa\2\[middot]s (Southall et al., 2007) which would be equivalent 
to a single pulse with a received level of approximately 181 to 186 dB 
re 1 [micro]Pa (rms), or a series of pulses for which the highest rms 
values are a few dB lower. Corresponding values for California sea 
lions and northern elephant seals (Mirounga angustirostris) are likely 
to be higher (Kastak et al., 2005).
    Permanent Threshold Shift--When PTS occurs, there is physical 
damage to the sound receptors in the ear. In severe cases, there can be 
total or partial deafness, whereas in other cases, the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter, 
1985). There is no specific evidence that exposure to pulses of airgun 
sound can cause PTS in any marine mammal, even with large arrays of 
airguns. However, given the possibility that mammals close to an airgun 
array might incur at least mild TTS, there has been further speculation 
about the possibility that some individuals occurring very close to 
airguns might incur PTS (e.g., Richardson et al., 1995, p. 372ff; 
Gedamke et al., 2008). Single or occasional occurrences of mild TTS are 
not indicative of permanent auditory damage, but repeated or (in some 
cases) single exposures to a level well above that causing TTS onset 
might elicit PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals but are assumed to be similar to those in humans and 
other terrestrial mammals (Southall et al., 2007). PTS might occur at a 
received sound level at least several dBs above that inducing mild TTS 
if the animal were exposed to strong sound pulses with rapid rise 
times. Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS threshold for impulse sounds (such as airgun 
pulses as received close to the source) is at least 6 dB higher than 
the TTS threshold on a peak-pressure basis, and probably greater than 6 
dB (Southall et al., 2007). Given the higher level of sound necessary 
to cause PTS as compared with TTS, it is considerably less likely that 
PTS would occur. Baleen whales generally avoid the immediate area 
around operating seismic vessels, as do some other marine mammals.
    Non-auditory Physiological Effects--Non-auditory physiological 
effects or injuries that theoretically might occur in marine mammals 
exposed to strong underwater sound include stress, neurological 
effects, bubble formation, resonance, and other types of organ or 
tissue damage (Cox et al., 2006; Southall et al., 2007). Studies 
examining such effects are limited. However, resonance effects (Gentry, 
2002) and direct noise-induced bubble formations (Crum et al., 2005) 
are implausible in the case of exposure to an impulsive broadband 
source like an airgun array. If seismic surveys disrupt diving patterns 
of deep-diving species, this might perhaps result in bubble formation 
and a form of the

[[Page 68526]]

bends, as speculated to occur in beaked whales exposed to sonar. 
However, there is no specific evidence of this upon exposure to airgun 
pulses.
    In general, very little is known about the potential for seismic 
survey sounds (or other types of strong underwater sounds) to cause 
non-auditory physical effects in marine mammals. Such effects, if they 
occur at all, would presumably be limited to short distances and to 
activities that extend over a prolonged period. The available data do 
not allow identification of a specific exposure level above which non-
auditory effects can be expected (Southall et al., 2007), or any 
meaningful quantitative predictions of the numbers (if any) of marine 
mammals that might be affected in those ways. Marine mammals that show 
behavioral avoidance of seismic vessels, including most baleen whales, 
some odontocetes, and some pinnipeds, are especially unlikely to incur 
non-auditory physical effects.
    Stranding and Mortality--When a living or dead marine mammal swims 
or floats onto shore and becomes ``beached'' or incapable of returning 
to sea, the event is termed a ``stranding'' (Geraci et al., 1999; 
Perrin and Geraci, 2002; Geraci and Lounsbury, 2005; NMFS, 2007). The 
legal definition for a stranding under the MMPA is that ``(A) a marine 
mammal is dead and is (i) on a beach or shore of the United States; or 
(ii) in waters under the jurisdiction of the United States (including 
any navigable waters); or (B) a marine mammal is alive and is (i) on a 
beach or shore of the United States and is unable to return to the 
water; (ii) on a beach or shore of the United States and, although able 
to return to the water is in need of apparent medical attention; or 
(iii) in the waters under the jurisdiction of the United States 
(including any navigable waters), but is unable to return to its 
natural habitat under its own power or without assistance.''
    Marine mammals are known to strand for a variety of reasons, such 
as infectious agents, biotoxicosis, starvation, fishery interaction, 
ship strike, unusual oceanographic or weather events, sound exposure, 
or combinations of these stressors sustained concurrently or in series. 
However, the cause or causes of most strandings are unknown (Geraci et 
al., 1976; Eaton, 1979; Odell et al., 1980; Best, 1982). Numerous 
studies suggest that the physiology, behavior, habitat relationships, 
age, or condition of cetaceans may cause them to strand or might pre-
dispose them to strand when exposed to another phenomenon. These 
suggestions are consistent with the conclusions of numerous other 
studies that have demonstrated that combinations of dissimilar 
stressors commonly combine to kill an animal or dramatically reduce its 
fitness, even though one exposure without the other does not produce 
the same result (Chroussos, 2000; Creel, 2005; DeVries et al., 2003; 
Fair and Becker, 2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a, 
2005b; Romero, 2004; Sih et al., 2004).
    Strandings Associated with Military Active Sonar--Several sources 
have published lists of mass stranding events of cetaceans in an 
attempt to identify relationships between those stranding events and 
military active sonar (Hildebrand, 2004; IWC, 2005; Taylor et al., 
2004). For example, based on a review of stranding records between 1960 
and 1995, the International Whaling Commission (2005) identified ten 
mass stranding events and concluded that, out of eight stranding events 
reported from the mid-1980s to the summer of 2003, seven had been 
coincident with the use of mid-frequency active sonar and most involved 
beaked whales.
    Over the past 12 years, there have been five stranding events 
coincident with military mid-frequency active sonar use in which 
exposure to sonar is believed to have been a contributing factor to 
strandings: Greece (1996); the Bahamas (2000); Madeira (2000); Canary 
Islands (2002); and Spain (2006). Refer to Cox et al. (2006) for a 
summary of common features shared by the strandings events in Greece 
(1996), Bahamas (2000), Madeira (2000), and Canary Islands (2002); and 
Fernandez et al., (2005) for an additional summary of the Canary 
Islands 2002 stranding event.
    Potential for Stranding from Seismic Surveys--Marine mammals close 
to underwater detonations of high explosives can be killed or severely 
injured, and the auditory organs are especially susceptible to injury 
(Ketten et al., 1993; Ketten, 1995). However, explosives are no longer 
used in marine waters for commercial seismic surveys or (with rare 
exceptions) for seismic research. These methods have been replaced 
entirely by airguns or related non-explosive pulse generators. Airgun 
pulses are less energetic and have slower rise times, and there is no 
specific evidence that they can cause serious injury, death, or 
stranding even in the case of large airgun arrays. However, the 
association of strandings of beaked whales with naval exercises 
involving mid-frequency active sonar (non-pulse sound) and, in one 
case, the regional co-occurrence of an L-DEO seismic survey (Malakoff, 
2002; Cox et al., 2006), has raised the possibility that beaked whales 
exposed to strong ``pulsed'' sounds could also be susceptible to injury 
and/or behavioral reactions that can lead to stranding (e.g., 
Hildebrand, 2005; Southall et al., 2007).
    Specific sound-related processes that lead to strandings and 
mortality are not well documented, but may include:
    (1) Swimming in avoidance of a sound into shallow water;
    (2) A change in behavior (such as a change in diving behavior) that 
might contribute to tissue damage, gas bubble formation, hypoxia, 
cardiac arrhythmia, hypertensive hemorrhage or other forms of trauma;
    (3) A physiological change such as a vestibular response leading to 
a behavioral change or stress-induced hemorrhagic diathesis, leading in 
turn to tissue damage; and
    (4) Tissue damage directly from sound exposure, such as through 
acoustically-mediated bubble formation and growth or acoustic resonance 
of tissues.

Some of these mechanisms are unlikely to apply in the case of impulse 
sounds. However, there are indications that gas-bubble disease 
(analogous to ``the bends''), induced in supersaturated tissue by a 
behavioral response to acoustic exposure, could be a pathologic 
mechanism for the strandings and mortality of some deep-diving 
cetaceans exposed to sonar. The evidence for this remains 
circumstantial and associated with exposure to naval mid-frequency 
sonar, not seismic surveys (Cox et al., 2006; Southall et al., 2007).
    Seismic pulses and mid-frequency sonar signals are quite different, 
and some mechanisms by which sonar sounds have been hypothesized to 
affect beaked whales are unlikely to apply to airgun pulses. Sounds 
produced by airgun arrays are broadband impulses with most of the 
energy below one kHz. Typical military mid-frequency sonar emits non-
impulse sounds at frequencies of 2 to 10 kHz, generally with a 
relatively narrow bandwidth at any one time. A further difference 
between seismic surveys and naval exercises is that naval exercises can 
involve sound sources on more than one vessel. Thus, it is not 
appropriate to expect that the same effects to marine mammals would 
result from military sonar and seismic surveys. However, evidence that 
sonar signals can, in special circumstances, lead (at least indirectly) 
to physical damage and mortality (e.g., Balcomb and Claridge, 2001; 
NOAA and USN, 2001; Jepson et al., 2003; Fern[aacute]ndez et al., 2004, 
2005; Hildebrand 2005; Cox et al., 2006)

[[Page 68527]]

suggests that caution is warranted when dealing with exposure of marine 
mammals to any high-intensity sound.
    There is no conclusive evidence of cetacean strandings or deaths at 
sea as a result of exposure to seismic surveys, but a few cases of 
strandings in the general area where a seismic survey was ongoing have 
led to speculation concerning a possible link between seismic surveys 
and strandings. Suggestions that there was a link between seismic 
surveys and strandings of humpback whales in Brazil (Engel et al., 
2004) were not well founded (IAGC, 2004; IWC, 2007). In September 2002, 
there was a stranding of two Cuvier's beaked whales in the Gulf of 
California, Mexico, when the L-DEO vessel R/V Maurice Ewing was 
operating a 20 airgun (8,490 in\3\) array in the general region. The 
link between the stranding and the seismic surveys was inconclusive and 
not based on any physical evidence (Hogarth, 2002; Yoder, 2002). 
Nonetheless, the Gulf of California incident plus the beaked whale 
strandings near naval exercises involving use of mid-frequency sonar 
suggests a need for caution in conducting seismic surveys in areas 
occupied by beaked whales until more is known about effects of seismic 
surveys on those species (Hildebrand, 2005). No injuries of beaked 
whales are anticipated during the proposed study because of:
    (1) The high likelihood that any beaked whales nearby would avoid 
the approaching vessel before being exposed to high sound levels, and
    (2) Differences between the sound sources to be used in the 
proposed study and operated by NSF and ASC and those involved in the 
naval exercises associated with strandings.

Potential Effects of Other Acoustic Devices and Sources

Multi-Beam Echosounder

    NSF and ASC would operate the Simrad EM120 multi-beam echosounder 
from the source vessel during the planned study. Sounds from the multi-
beam echosounder are very short pulses, occurring for approximately 15 
ms, depending on water depth. Most of the energy in the sound pulses 
emitted by the multi-beam echosounder is at frequencies near 12 kHz, 
and the maximum source level is 242 dB re 1 [mu]Pa (rms). The beam is 
narrow (1 to 2[deg]) in fore-aft extent and wide (150[deg]) in the 
cross-track extent. Each ping consists of nine (in water greater than 
1,000 m deep) consecutive successive fan-shaped transmissions 
(segments) at different cross-track angles. Any given mammal at depth 
near the trackline would be in the main beam for only one or two of the 
nine segments. Also, marine mammals that encounter the Simrad EM120 are 
unlikely to be subjected to repeated pulses because of the narrow fore-
aft width of the beam and would receive only limited amounts of pulse 
energy because of the short pulses. Animals close to the ship (where 
the beam is narrowest) are especially unlikely to be ensonified for 
more than one 15 ms pulse (or two pulses if in the overlap area). 
Similarly, Kremser et al. (2005) noted that the probability of a 
cetacean swimming through the area of exposure when a multi-beam 
echosounder emits a pulse is small. The animal would have to pass the 
transducer at close range and be swimming at speeds similar to the 
vessel in order to receive the multiple pulses that might result in 
sufficient exposure to cause TTS.
    Navy sonars that have been linked to avoidance reactions and 
stranding of cetaceans: (1) Generally have longer pulse duration than 
the Simrad EM120; and (2) are often directed close to horizontally, as 
well as omnidirectional, versus more downward and narrowly for the 
multi-beam echosounder. The area of possible influence of the multi-
beam echosounder is much smaller--a narrow band below the source 
vessel. Also, the duration of exposure for a given marine mammal can be 
much longer for naval sonar. During NSF and ASC's operations, the 
individual pulses would be very short, and a given mammal would not 
receive many of the downward-directed pulses as the vessel passes by. 
Possible effects of a multi-beam echosounder on marine mammals are 
described below.
    Stranding--In 2013, an International Scientific Review Panel 
investigated a 2008 mass stranding of approximately 100 melon-headed 
whales in a Madagascar lagoon system (Southall et al., 2013) associated 
with the use of a high-frequency mapping system. The report indicated 
that the use of a 12 kHz multi-beam echosounder was the most plausible 
and likely initial behavioral trigger of the mass stranding event. This 
was the first time that a relatively high-frequency mapping sonar 
system has been associated with a stranding event. However, the report 
also notes that there were several site- and situation-specific 
secondary factors that may have contributed to the avoidance responses 
that lead to the eventual entrapment and mortality of the whales within 
the Loza Lagoon system (e.g., the survey vessel transiting in a north-
south direction on the shelf break parallel to the shore may have 
trapped the animals between the sound source and the shore driving them 
towards the Loza Lagoon). The report concluded that for odontocete 
cetaceans that hear well in the 10 to 50 kHz range, where ambient noise 
is typically quite low, high-power active sonars operating in this 
range may be more easily audible and have potential effects over larger 
areas than low-frequency systems that have more typically been 
considered in terms of anthropogenic noise impacts (Southall et al., 
2013). However, the risk may be very low given the extensive use of 
these systems worldwide on a daily basis and the lack of direct 
evidence of such responses previously (Southall et al., 2013).
    Masking--Marine mammal communications would not be masked 
appreciably by the multi-beam echosounder signals, given the low duty 
cycle of the echosounder and the brief period when an individual mammal 
is likely to be within its beam. Furthermore, in the case of baleen 
whales, the multi-beam echosounder signals (12 kHz) generally do not 
overlap with the predominant frequencies in the calls (16 Hz to less 
than 12 kHz), which would avoid any significant masking (Richardson et 
al., 1995).
    Behavioral Responses--Behavioral reactions of free-ranging marine 
mammals to sonars, echosounders, and other sound sources appear to vary 
by species and circumstance. Observed reactions have included silencing 
and dispersal by sperm whales (Watkins et al., 1985), increased 
vocalizations and no dispersal by pilot whales (Rendell and Gordon, 
1999), and the previously-mentioned beachings by beaked whales. During 
exposure to a 21 to 25 kHz ``whale-finding'' sonar with a source level 
of 215 dB re 1 [micro]Pa, gray whales reacted by orienting slightly 
away from the source and being deflected from their course by 
approximately 200 m (656.2 ft) (Frankel, 2005). When a 38 kHz 
echosounder and a 150 kHz ADCP were transmitting during studies in the 
Eastern Tropical Pacific, baleen whales showed no significant 
responses, while spotted and spinner dolphins were detected slightly 
more often and beaked whales less often during visual surveys 
(Gerrodette and Pettis, 2005).
    Captive bottlenose dolphins and a beluga whale exhibited changes in 
behavior when exposed to 1 second tonal signals at frequencies similar 
to those that would be emitted by the multi-beam echosounder used by 
NSF and ASC, and to shorter broadband pulsed signals. Behavioral 
changes typically involved what appeared to be deliberate attempts to 
avoid the sound

[[Page 68528]]

exposure (Schlundt et al., 2000; Finneran et al., 2002; Finneran and 
Schlundt, 2004). The relevance of those data to free-ranging 
odontocetes is uncertain, and in any case, the test sounds were quite 
different in duration as compared with those from a multi-beam 
echosounder.
    Hearing Impairment and Other Physical Effects--Given several 
stranding events that have been associated with the operation of naval 
sonar in specific circumstances, there is concern that mid-frequency 
sonar sounds can cause serious impacts to marine mammals (see above). 
However, the multi-beam echosounder proposed for use by NSF and ASC is 
quite different than sonar used for Navy operations. Pulse duration of 
the multi-beam echosounder is very short relative to the naval sonar. 
Also, at any given location, an individual marine mammal would be in 
the beam of the multi-beam echosounder for much less time, given the 
generally downward orientation of the beam and its narrow fore-aft 
beamwidth; Navy sonar often uses near-horizontally-directed sound. 
Those factors would all reduce the sound energy received from the 
multi-beam echosounder rather drastically relative to that from naval 
sonar. NMFS believes that the brief exposure of marine mammals to one 
pulse, or small numbers of signals, from the multi-beam echosounder in 
this particular case is not likely to result in the harassment of 
marine mammals.

Single-Beam Echosounder

    NSF and ASC would operate the Knudsen 3260 and Bathy 2000 single-
beam echosounders from the source vessel during the planned study. 
Sounds from the single-beam echosounder are very short pulses, 
depending on water depth. Most of the energy in the sound pulses 
emitted by the singlebeam echosounder is at frequencies near 12 kHz for 
bottom-tracking purposes or at 3.5 kHz in the sub-bottom profiling 
mode. The sonar emits energy in a 30[deg] beam from the bottom of the 
ship. Marine mammals that encounter the Knudsen 3260 or Bathy 2000 are 
unlikely to be subjected to repeated pulses because of the relatively 
narrow fore-aft width of the beam and would receive only limited 
amounts of pulse energy because of the short pulses. Animals close to 
the ship (where the beam is narrowest) are especially unlikely to be 
ensonified for more than one pulse (or two pulses if in the overlap 
area). Similarly, Kremser et al. (2005) noted that the probability of a 
cetacean swimming through the area of exposure when a single-beam 
echosounder emits a pulse is small. The animal would have to pass the 
transducer at close range and be swimming at speeds similar to the 
vessel in order to receive the multiple pulses that might result in 
sufficient exposure to cause TTS.
    Navy sonars that have been linked to avoidance reactions and 
stranding of cetaceans: (1) Generally have longer pulse duration than 
the Knudsen 3260 or Bathy 2000; and (2) are often directed close to 
horizontally versus more downward for the echosounder. The area of 
possible influence of the single-beam echosounder is much smaller--a 
narrow band below the source vessel. Also, the duration of exposure for 
a given marine mammal can be much longer for naval sonar. During NSF 
and ASC's operations, the individual pulses would be very short, and a 
given mammal would not receive many of the downward-directed pulses as 
the vessel passes by. Possible effects of a single-beam echosounder on 
marine mammals are described below.
    Masking--Marine mammal communications would not be masked 
appreciably by the single-beam echosounder signals given the low duty 
cycle of the echosounder and the brief period when an individual mammal 
is likely to be within its beam. Furthermore, in the case of baleen 
whales, the single-beam echosounder signals (12 or 3.5 kHz) do not 
overlap with the predominant frequencies in the calls (16 Hz to less 
than 12 kHz), which would avoid any significant masking (Richardson et 
al., 1995).
    Behavioral Responses--Behavioral reactions of free-ranging marine 
mammals to sonars, echosounders, and other sound sources appear to vary 
by species and circumstance. Observed reactions have included silencing 
and dispersal by sperm whales (Watkins et al., 1985), increased 
vocalizations and no dispersal by pilot whales (Rendell and Gordon, 
1999), and the previously-mentioned beachings by beaked whales. During 
exposure to a 21 to 25 kHz ``whale-finding'' sonar with a source level 
of 215 dB re 1 [micro]Pa, gray whales reacted by orienting slightly 
away from the source and being deflected from their course by 
approximately 200 m (656.2 ft) (Frankel, 2005). When a 38 kHz 
echosounder and a 150 kHz ADCP were transmitting during studies in the 
Eastern Tropical Pacific, baleen whales showed no significant 
responses, while spotted and spinner dolphins were detected slightly 
more often and beaked whales less often during visual surveys 
(Gerrodette and Pettis, 2005).
    Captive bottlenose dolphins and a beluga whale exhibited changes in 
behavior when exposed to 1 second tonal signals at frequencies similar 
to those that would be emitted by the single-beam echosounder used by 
NSF and ASC, and to shorter broadband pulsed signals. Behavioral 
changes typically involved what appeared to be deliberate attempts to 
avoid the sound exposure (Schlundt et al., 2000; Finneran et al., 2002; 
Finneran and Schlundt, 2004). The relevance of those data to free-
ranging odontocetes is uncertain, and in any case, the test sounds were 
quite different in duration as compared with those from a single-beam 
echosounder.
    Hearing Impairment and Other Physical Effects--Given recent 
stranding events that have been associated with the operation of naval 
sonar, there is concern that mid-frequency sonar sounds can cause 
serious impacts to marine mammals (see above). However, the single-beam 
echosounder proposed for use by NSF and ASC is quite different than 
sonar used for Navy operations. Pulse duration of the single-beam 
echosounder is very short relative to the naval sonar. Also, at any 
given location, an individual marine mammal would be in the beam of the 
single-beam echosounder for much less time given the generally downward 
orientation of the beam and its narrow fore-aft beamwidth; Navy sonar 
often uses near-horizontally-directed sound. Those factors would all 
reduce the sound energy received from the single-beam echosounder 
rather drastically relative to that from naval sonar. NMFS believes 
that the brief exposure of marine mammals to one pulse, or small 
numbers of signals, from the single-beam echosounder in this particular 
case is not likely to result in the harassment of marine mammals.

Acoustic Doppler Current Profilers

    NSF and ASC would operate the ADCP Teledyne RDI VM-150 and ADCP 
Ocean Surveyor OS-38 from the source vessel during the planned study. 
Most of the energy in the sound pulses emitted by the ADCPs operate at 
frequencies near 150 kHz, and the maximum source level is 223.6 dB re 1 
[mu]Pa (rms). Sound energy from the ADCP is emitted as a 30[deg] 
conically-shaped beam. Marine mammals that encounter the ADCPs are 
unlikely to be subjected to repeated pulses because of the relatively 
narrow fore-aft width of the beam and would receive only limited 
amounts of pulse energy because of the short pulses. Animals close to 
the ship (where the beam is narrowest) are especially unlikely to be 
ensonified for more than one 15 ms pulse (or two pulses if in the 
overlap area). Similarly,

[[Page 68529]]

Kremser et al. (2005) noted that the probability of a cetacean swimming 
through the area of exposure when the ADCPs emit a pulse is small. The 
animal would have to pass the transducer at close range and be swimming 
at speeds similar to the vessel in order to receive the multiple pulses 
that might result in sufficient exposure to cause TTS.
    Navy sonars that have been linked to avoidance reactions and 
stranding of cetaceans: (1) Generally have longer pulse duration than 
the ADCPs; and (2) are often directed close to horizontally versus more 
downward for the ADCPs. The area of possible influence of the ADCPs is 
much smaller--a narrow band below the source vessel. Also, the duration 
of exposure for a given marine mammal can be much longer for naval 
sonar. During NSF and ASC's operations, the individual pulses would be 
very short, and a given mammal would not receive many of the downward-
directed pulses as the vessel passes by. Possible effects of the ADCPs 
on marine mammals are described below.
    Masking--Marine mammal communications would not be masked 
appreciably by the ADCP signals, given the low duty cycle of the ADCPs 
and the brief period when an individual mammal is likely to be within 
its beam. Furthermore, in the case of baleen whales, the ADCP signals 
(150 kHz) do not overlap with the predominant frequencies in the calls 
(16 Hz to less than 12 kHz), which would avoid any significant masking 
(Richardson et al., 1995).
    Behavioral Responses--Behavioral reactions of free-ranging marine 
mammals to sonars, echosounders, and other sound sources appear to vary 
by species and circumstance. Observed reactions have included silencing 
and dispersal by sperm whales (Watkins et al., 1985), increased 
vocalizations and no dispersal by pilot whales (Rendell and Gordon, 
1999), and the previously-mentioned beachings by beaked whales. During 
exposure to a 21 to 25 kHz ``whale-finding'' sonar with a source level 
of 215 dB re 1 [micro]Pa, gray whales reacted by orienting slightly 
away from the source and being deflected from their course by 
approximately 200 m (656.2 ft) (Frankel, 2005). When a 38 kHz 
echosounder and a 150 kHz ADCP were transmitting during studies in the 
Eastern Tropical Pacific, baleen whales showed no significant 
responses, while spotted and spinner dolphins were detected slightly 
more often and beaked whales less often during visual surveys 
(Gerrodette and Pettis, 2005).
    Captive bottlenose dolphins and a beluga whale exhibited changes in 
behavior when exposed to 1 second tonal signals at frequencies similar 
to those that would be emitted by the ADCPs used by NSF and ASC, and to 
shorter broadband pulsed signals. Behavioral changes typically involved 
what appeared to be deliberate attempts to avoid the sound exposure 
(Schlundt et al., 2000; Finneran et al., 2002; Finneran and Schlundt, 
2004). The relevance of those data to free-ranging odontocetes is 
uncertain, and in any case, the test sounds were quite different in 
duration as compared with those from an ADCP.
    Hearing Impairment and Other Physical Effects--Given recent 
stranding events that have been associated with the operation of naval 
sonar, there is concern that mid-frequency sonar sounds can cause 
serious impacts to marine mammals (see above). However, the ADCPs 
proposed for use by NSF and ASC is quite different than sonar used for 
Navy operations. Pulse duration of the ADCPs is very short relative to 
the naval sonar. Also, at any given location, an individual marine 
mammal would be in the beam of the ADCPs for much less time given the 
generally downward orientation of the beam and its narrow fore-aft 
beamwidth; Navy sonar often uses near-horizontally-directed sound. 
Those factors would all reduce the sound energy received from the ADCPs 
rather drastically relative to that from naval sonar. NMFS believes 
that the brief exposure of marine mammals to one pulse, or small 
numbers of signals, from the ADCPs in this particular case is not 
likely to result in the harassment of marine mammals.

Coring Activities

    During coring, the noise created by the mechanical action of the 
devices on the seafloor is expected to be perceived by nearby fish and 
other marine organisms and deter them from swimming toward the source. 
Coring activities would be highly localized and short-term in duration 
and would not be expected to significantly interfere with marine mammal 
behavior. The potential direct effects include temporary localized 
disturbance or displacement from associated sounds and/or physical 
movement/actions of the operations. Additionally, the potential 
indirect effects may consist of very localized and transitory/short-
term disturbance of bottom habitat and associated prey in shallow-water 
areas as a result of coring and sediment sampling (NSF/USGS PEIS, 
2011). NMFS believes that the brief exposure of marine mammals to noise 
created from the mechanical action of the devices for coring is not 
likely to result in the harassment of marine mammals.
    A maximum total of 32 coring samples would be obtained using these 
devices and ranging from 1.5 to 3 hours per sample and it is estimated 
that the pinger would operate a total of 96 hours. The vessel would be 
stationary during core sampling deployment and recovery, so the 
likelihood of a collision or entanglement with a marine mammal is very 
low.

Vessel Movement and Collisions

    Vessel movement in the vicinity of marine mammals has the potential 
to result in either a behavioral response or a direct physical 
interaction. Both scenarios are discussed below in this section.
    Behavioral Responses to Vessel Movement--There are limited data 
concerning marine mammal behavioral responses to vessel traffic and 
vessel noise, and a lack of consensus among scientists with respect to 
what these responses mean or whether they result in short-term or long-
term adverse effects. In those cases where there is a busy shipping 
lane or where there is a large amount of vessel traffic, marine mammals 
(especially low frequency specialists) may experience acoustic masking 
(Hildebrand, 2005) if they are present in the area (e.g., killer whales 
in Puget Sound; Foote et al., 2004; Holt et al., 2008). In cases where 
vessels actively approach marine mammals (e.g., whale watching or 
dolphin watching boats), scientists have documented that animals 
exhibit altered behavior such as increased swimming speed, erratic 
movement, and active avoidance behavior (Bursk, 1983; Acevedo, 1991; 
Baker and MacGibbon, 1991; Trites and Bain, 2000; Williams et al., 
2002; Constantine et al., 2003), reduced blow interval (Ritcher et al., 
2003), disruption of normal social behaviors (Lusseau, 2003, 2006), and 
the shift of behavioral activities which may increase energetic costs 
(Constantine et al., 2003, 2004). A detailed review of marine mammal 
reactions to ships and boats is available in Richardson et al., (1995). 
For each of the marine mammal taxonomy groups, Richardson et al., 
(1995) provides the following assessment regarding reactions to vessel 
traffic:
    Toothed whales--``In summary, toothed whales sometimes show no 
avoidance reaction to vessels, or even approach them. However, 
avoidance can occur, especially in response to vessels of types used to 
chase or hunt the animals. This may cause temporary displacement, but 
we know of no clear

[[Page 68530]]

evidence that toothed whales have abandoned significant parts of their 
range because of vessel traffic.''
    Baleen whales--``When baleen whales receive low-level sounds from 
distant or stationary vessels, the sounds often seem to be ignored. 
Some whales approach the sources of these sounds. When vessels approach 
whales slowly and non-aggressively, whales often exhibit slow and 
inconspicuous avoidance maneuvers. In response to strong or rapidly 
changing vessel noise, baleen whales often interrupt their normal 
behavior and swim rapidly away. Avoidance is especially strong when a 
boat heads directly toward the whale.''
    Behavioral responses to stimuli are complex and influenced to 
varying degrees by a number of factors, such as species, behavioral 
contexts, geographical regions, source characteristics (moving or 
stationary, speed, direction, etc.), prior experience of the animal and 
physical status of the animal. For example, studies have shown that 
beluga whales' reaction varied when exposed to vessel noise and 
traffic. In some cases, beluga whales exhibited rapid swimming from 
ice-breaking vessels up to 80 km (43.2 nmi) away and showed changes in 
surfacing, breathing, diving, and group composition in the Canadian 
high Arctic where vessel traffic is rare (Finley et al., 1990). In 
other cases, beluga whales were more tolerant of vessels, but responded 
differentially to certain vessels and operating characteristics by 
reducing their calling rates (especially older animals) in the St. 
Lawrence River where vessel traffic is common (Blane and Jaakson, 
1994). In Bristol Bay, Alaska, beluga whales continued to feed when 
surrounded by fishing vessels and resisted dispersal even when 
purposefully harassed (Fish and Vania, 1971).
    In reviewing more than 25 years of whale observation data, Watkins 
(1986) concluded that whale reactions to vessel traffic were ``modified 
by their previous experience and current activity: Habituation often 
occurred rapidly, attention to other stimuli or preoccupation with 
other activities sometimes overcame their interest or wariness of 
stimuli.'' Watkins noticed that over the years of exposure to ships in 
the Cape Cod area, minke whales changed from frequent positive interest 
(e.g., approaching vessels) to generally uninterested reactions; fin 
whales changed from mostly negative (e.g., avoidance) to uninterested 
reactions; fin whales changed from mostly negative (e.g., avoidance) to 
uninterested reactions; right whales apparently continued the same 
variety of responses (negative, uninterested, and positive responses) 
with little change; and humpbacks dramatically changed from mixed 
responses that were often negative to reactions that were often 
strongly positive. Watkins (1986) summarized that ``whales near shore, 
even in regions with low vessel traffic, generally have become less 
wary of boats and their noises, and they have appeared to be less 
easily disturbed than previously. In particular locations with intense 
shipping and repeated approaches by boats (such as the whale-watching 
areas of Stellwagen Bank), more and more whales had positive reactions 
to familiar vessels, and they also occasionally approached other boats 
and yachts in the same ways.''
    Although the radiated sound from the Palmer would be audible to 
marine mammals over a large distance, it is unlikely that marine 
mammals would respond behaviorally (in a manner that NMFS would 
consider harassment under the MMPA) to low-level distant shipping noise 
as the animals in the area are likely to be habituated to such noises 
(Nowacek et al., 2004). In light of these facts, NMFS does not expect 
the Palmer's movements to result in Level B harassment.
    Vessel Strike--Ship strikes of cetaceans can cause major wounds, 
which may lead to the death of the animal. An animal at the surface 
could be struck directly by a vessel, a surfacing animal could hit the 
bottom of a vessel, or an animal just below the surface could be cut by 
a vessel's propeller. The severity of injuries typically depends on the 
size and speed of the vessel (Knowlton and Kraus, 2001; Laist et al., 
2001; Vanderlaan and Taggart, 2007).
    The most vulnerable marine mammals are those that spend extended 
periods of time at the surface in order to restore oxygen levels within 
their tissues after deep dives (e.g., the sperm whale). In addition, 
some baleen whales, such as the North Atlantic right whale, seem 
generally unresponsive to vessel sound, making them more susceptible to 
vessel collisions (Nowacek et al., 2004). These species are primarily 
large, slow moving whales. Smaller marine mammals (e.g., bottlenose 
dolphins) move quickly through the water column and are often seen 
riding the bow wave of large ships. Marine mammal responses to vessels 
may include avoidance and changes in dive pattern (NRC, 2003).
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike results in death (Knowlton and Kraus, 2001; 
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart, 
2007). In assessing records in which vessel speed was known, Laist et 
al. (2001) found a direct relationship between the occurrence of a 
whale strike and the speed of the vessel involved in the collision. The 
authors concluded that most deaths occurred when a vessel was traveling 
in excess of 13 kts (24.1 km/hr, 14.9 mph).
    NSF and ASC's proposed operation of one source vessel for the 
proposed low-energy seismic survey is relatively small in scale (i.e., 
a one vessel operation) compared to the number of other ships (e.g., 
fishing, tourist, and other vessels supporting McMurdo Station 
operations) transiting at higher speeds in the same areas on an annual 
basis. The probability of vessel and marine mammal interactions 
occurring during the proposed low-energy seismic survey is unlikely due 
to the Palmer's slow operational speed, which is typically 5 kts. 
Outside of seismic operations, the Palmer's cruising speed would be 
approximately 10.1 to 14.5 kts, which is generally below the speed at 
which studies have noted reported increases of marine mammal injury or 
death (Laist et al., 2001).
    As a final point, the Palmer has a number of other advantages for 
avoiding ship strikes as compared to most commercial merchant vessels, 
including the following: The Palmer's bridge and aloft observation 
tower offers good visibility to visually monitor for marine mammal 
presence; PSOs posted during operations scan the ocean for marine 
mammals and must report visual alerts of marine mammal presence to 
crew; and the PSOs receive extensive training that covers the 
fundamentals of visual observing for marine mammals and information 
about marine mammals and their identification at sea.

Entanglement

    Entanglement can occur if wildlife becomes immobilized in survey 
lines, cables, nets, or other equipment that is moving through the 
water column. The proposed low-energy seismic survey would require 
towing approximately one or two 100 m cable streamers. While towing 
this size of an array carries some level of risk of entanglement for 
marine mammals due to the operational nature of the activity, 
entanglement is unlikely. Wildlife, especially slow moving individuals, 
such as large whales, have a low probability of becoming entangled due 
to slow speed of the survey vessel and onboard monitoring efforts. In 
May 2011, there was one recorded entrapment of an olive ridley sea 
turtle (Lepidochelys olivacea) in the R/V

[[Page 68531]]

Marcus G. Langseth's barovanes after the conclusion of a seismic survey 
off Costa Rica. There have been cases of baleen whales, mostly gray 
whales (Heyning, 1990), becoming entangled in fishing lines. The 
probability for entanglement of marine mammals is considered very low 
because of the vessel speed and the monitoring efforts onboard the 
survey vessel. Furthermore, there has been no history of marine mammal 
entanglement with seismic equipment used by the U.S. academic research 
fleet.

Icebreaking Activities

    Icebreakers produce more noise while breaking ice than ships of 
comparable size due, primarily, to the sounds of propeller cavitating 
(Richardson et al., 1995). Multi-year ice is expected to be encountered 
in the proposed action area. Icebreakers commonly back and ram into 
heavy ice until losing momentum to make way. The highest noise levels 
usually occur while backing full astern in preparation to ram forward 
through the ice. Overall the noise generated by an icebreaker pushing 
ice was 10 to 15 dB greater than the noise produced by the ship 
underway in open water (Richardson et al., 1995). In general, the 
Antarctic and Southern Ocean is a noisy environment. Calving and 
grounding icebergs as well as the break-up of ice sheets, can produce a 
large amount of underwater noise. Little information is available about 
the increased sound levels due to icebreaking.
    Cetaceans--Few studies have been conducted to evaluate the 
potential interference of icebreaking noise with marine mammal 
vocalizations. Erbe and Farmer (1998) measured masked hearing 
thresholds of a captive beluga whale. They reported that the recording 
of a Canadian Coast Guard Ship (CCGS) Henry Larsen, ramming ice in the 
Beaufort Sea, masked recordings of beluga vocalizations at a noise to 
signal pressure ratio of 18 dB, when the noise pressure level was eight 
times as high as the call pressure. Erbe and Farmer (2000) also 
predicted when icebreaker noise would affect beluga whales through 
software that combined a sound propagation model and beluga whale 
impact threshold models. They again used the data from the recording of 
the Henry Larsen in the Beaufort Sea and predicted that masking of 
beluga whale vocalizations could extend between 40 and 71 km (21.6 and 
38.3 nmi) near the surface. Lesage et al. (1999) report that beluga 
whales changed their call type and call frequency when exposed to boat 
noise. It is possible that the whales adapt to the ambient noise levels 
and are able to communicate despite the sound. Given the documented 
reaction of belugas to ships and icebreakers it is highly unlikely that 
beluga whales would remain in the proximity of vessels where 
vocalizations would be masked.
    Beluga whales have been documented swimming rapidly away from ships 
and icebreakers in the Canadian high Arctic when a ship approaches to 
within 35 to 50 km (18.9 to 27 nmi), and they may travel up to 80 km 
(43.2 nmi) from the vessel's track (Richardson et al., 1995). It is 
expected that belugas avoid icebreakers as soon as they detect the 
ships (Cosens and Dueck, 1993). However, the reactions of beluga whales 
to ships vary greatly and some animals may become habituated to high 
levels of ambient noise (Erbe and Darmber, 2000).
    There is little information about the effects of icebreaking ships 
on baleen whales. Migrating bowhead whales appeared to avoid an area 
around a drill site by greater than 25 km (13.5 mi) where an icebreaker 
was working in the Beaufort Sea. There was intensive icebreaking daily 
in support of the drilling activities (Brewer et al., 1993). Migrating 
bowheads also avoided a nearby drill site at the same time of year 
where little icebreaking was being conducted (LGL and Greeneridge, 
1987). It is unclear as to whether the drilling activities, icebreaking 
operations, or the ice itself might have been the cause for the whale's 
diversion. Bowhead whales are not expected to occur in the proximity of 
the proposed action area.
    Pinnipeds--Brueggeman et al. (1992) reported on the reactions of 
seals to an icebreaker during activities at two prospects in the 
Chukchi Sea. Reactions of seals to the icebreakers varied between the 
two prospects. Most (67%) seals did not react to the icebreaker at 
either prospect. Reaction at one prospect was greatest during 
icebreaking activity (running/maneuvering/jogging) and was 0.23 km 
(0.12 nmi) of the vessel and lowest for animals beyond 0.93 km (0.5 
nmi). At the second prospect however, seal reaction was lowest during 
icebreaking activity with higher and similar levels of response during 
general (non-icebreaking) vessel operations and when the vessel was at 
anchor or drifting. The frequency of seal reaction generally declined 
with increasing distance from the vessel except during general vessel 
activity where it remained consistently high to about 0.46 km (0.25 
nmi) from the vessel before declining.
    Similarly, Kanik et al. (1980) found that ringed (Pusa hispida) and 
harp seals (Pagophilus groenlandicus) often dove into the water when an 
icebreaker was breaking ice within 1 km (0.5 nmi) of the animals. Most 
seals remained on the ice when the ship was breaking ice 1 to 2 km (0.5 
to 1.1 nmi) away.
    The potential effects to marine mammals described in this section 
of the document do not take into consideration the proposed monitoring 
and mitigation measures described later in this document (see the 
``Proposed Mitigation'' and ``Proposed Monitoring and Reporting'' 
sections) which, as noted are designed to effect the least practicable 
impact on affected marine mammal species and stocks.

Anticipated Effects on Marine Mammal Habitat

    The proposed low-energy seismic survey is not anticipated to have 
any permanent impact on habitats used by the marine mammals in the 
proposed study area, including the food sources they use (i.e. fish and 
invertebrates). Additionally, no physical damage to any habitat is 
anticipated as a result of conducting airgun operations during the 
proposed low-energy seismic survey. While it is anticipated that the 
specified activity may result in marine mammals avoiding certain areas 
due to temporary ensonification, this impact to habitat is temporary 
and was considered in further detail earlier in this document, as 
behavioral modification. The main impact associated with the proposed 
activity would be temporarily elevated noise levels and the associated 
direct effects on marine mammals in any particular area of the 
approximately 3,882 km\2\ proposed study area, previously discussed in 
this notice.
    The Palmer is designed for continuous passage at 3 kts through ice 
1 m thick. During the proposed project the Palmer would typically 
encounter first- or second-year ice while avoiding thicker ice floes, 
particularly large intact multi-year ice, whenever possible. In 
addition, the vessel would follow leads when possible while following 
the survey route. As the vessel passes through the ice, the ship causes 
the ice to part and travel alongside the hull. This ice typically 
returns to fill the wake as the ship passes. The effects are transitory 
(i.e., hours at most) and localized (i.e., constrained to a relatively 
narrow swath perhaps 10 m [32.1 ft] to each side of the vessel). The 
Palmer's maximum beam is 18.3 m (60 ft). Applying the maximum estimated 
amount of icebreaking (500 km), to the corridor opened by the ship, NSF 
and ASC anticipate that a maximum of approximately 18 km\2\ (5.3 
nmi\2\) of ice may be disturbed. This represents an

[[Page 68532]]

inconsequential amount of the total ice present in the Southern Ocean.
    Sea ice is important for pinniped life functions such as resting, 
breeding, and molting. Icebreaking activities may damage seal breathing 
holes and would also reduce the haul-out area in the immediate vicinity 
of the ship's track. Icebreaking along a maximum of 500 km of 
tracklines would alter local ice conditions in the immediate vicinity 
of the vessel. This has the potential to temporarily lead to a 
reduction of suitable seal haul-out habitat. However, the dynamic sea-
ice environment requires that seals be able to adapt to changes in sea, 
ice, and snow conditions, and they therefore create new breathing holes 
and lairs throughout the winter and spring (Hammill and Smith, 1989). 
In addition, seals often use open leads and cracks in the ice to 
surface and breathe (Smith and Stirling, 1975). Disturbance of the ice 
would occur in a very small area relative to the Southern Ocean ice-
pack and no significant impact on marine mammals is anticipated by 
icebreaking during the proposed low-energy seismic survey. The next 
section discusses the potential impacts of anthropogenic sound sources 
on common marine mammal prey in the proposed study area (i.e., fish and 
invertebrates).

Anticipated Effects on Fish

    One reason for the adoption of airguns as the standard energy 
source for marine seismic surveys is that, unlike explosives, they have 
not been associated with large-scale fish kills. However, existing 
information on the impacts of seismic surveys on marine fish and 
invertebrate populations is limited. There are three types of potential 
effects of exposure to seismic surveys: (1) Pathological, (2) 
physiological, and (3) behavioral. Pathological effects involve lethal 
and temporary or permanent sub-lethal injury. Physiological effects 
involve temporary and permanent primary and secondary stress responses, 
such as changes in levels of enzymes and proteins. Behavioral effects 
refer to temporary and (if they occur) permanent changes in exhibited 
behavior (e.g., startle and avoidance behavior). The three categories 
are interrelated in complex ways. For example, it is possible that 
certain physiological and behavioral changes could potentially lead to 
an ultimate pathological effect on individuals (i.e., mortality).
    The specific received sound levels at which permanent adverse 
effects to fish potentially could occur are little studied and largely 
unknown. Furthermore, the available information on the impacts of 
seismic surveys on marine fish is from studies of individuals or 
portions of a population; there have been no studies at the population 
scale. The studies of individual fish have often been on caged fish 
that were exposed to airgun pulses in situations not representative of 
an actual seismic survey. Thus, available information provides limited 
insight on possible real-world effects at the ocean or population 
scale. This makes drawing conclusions about impacts on fish problematic 
because, ultimately, the most important issues concern effects on 
marine fish populations, their viability, and their availability to 
fisheries.
    Hastings and Popper (2005), Popper (2009), and Popper and Hastings 
(2009a,b) provided recent critical reviews of the known effects of 
sound on fish. The following sections provide a general synopsis of the 
available information on the effects of exposure to seismic and other 
anthropogenic sound as relevant to fish. The information comprises 
results from scientific studies of varying degrees of rigor plus some 
anecdotal information. Some of the data sources may have serious 
shortcomings in methods, analysis, interpretation, and reproducibility 
that must be considered when interpreting their results (see Hastings 
and Popper, 2005). Potential adverse effects of the program's sound 
sources on marine fish are noted.
    Pathological Effects--The potential for pathological damage to 
hearing structures in fish depends on the energy level of the received 
sound and the physiology and hearing capability of the species in 
question. For a given sound to result in hearing loss, the sound must 
exceed, by some substantial amount, the hearing threshold of the fish 
for that sound (Popper, 2005). The consequences of temporary or 
permanent hearing loss in individual fish on a fish population are 
unknown; however, they likely depend on the number of individuals 
affected and whether critical behaviors involving sound (e.g., predator 
avoidance, prey capture, orientation and navigation, reproduction, 
etc.) are adversely affected.
    Little is known about the mechanisms and characteristics of damage 
to fish that may be inflicted by exposure to seismic survey sounds. Few 
data have been presented in the peer-reviewed scientific literature. As 
far as NSF, ASC, and NMFS know, there are only two papers with proper 
experimental methods, controls, and careful pathological investigation 
implicating sounds produced by actual seismic survey airguns in causing 
adverse anatomical effects. One such study indicated anatomical damage, 
and the second indicated TTS in fish hearing. The anatomical case is 
McCauley et al. (2003), who found that exposure to airgun sound caused 
observable anatomical damage to the auditory maculae of pink snapper 
(Pagrus auratus). This damage in the ears had not been repaired in fish 
sacrificed and examined almost two months after exposure. On the other 
hand, Popper et al. (2005) documented only TTS (as determined by 
auditory brainstem response) in two of three fish species from the 
Mackenzie River Delta. This study found that broad whitefish (Coregonus 
nasus) exposed to five airgun shots were not significantly different 
from those of controls. During both studies, the repetitive exposure to 
sound was greater than would have occurred during a typical seismic 
survey. However, the substantial low-frequency energy produced by the 
airguns (less than 400 Hz in the study by McCauley et al. [2003] and 
less than approximately 200 Hz in Popper et al. [2005]) likely did not 
propagate to the fish because the water in the study areas was very 
shallow (approximately nine m in the former case and less than two m in 
the latter). Water depth sets a lower limit on the lowest sound 
frequency that would propagate (the ``cutoff frequency'') at about one-
quarter wavelength (Urick, 1983; Rogers and Cox, 1988).
    Wardle et al. (2001) suggested that in water, acute injury and 
death of organisms exposed to seismic energy depends primarily on two 
features of the sound source: (1) The received peak pressure, and (2) 
the time required for the pressure to rise and decay. Generally, as 
received pressure increases, the period for the pressure to rise and 
decay decreases, and the chance of acute pathological effects 
increases. According to Buchanan et al. (2004), for the types of 
seismic airguns and arrays involved with the proposed program, the 
pathological (mortality) zone for fish would be expected to be within a 
few meters of the seismic source. Numerous other studies provide 
examples of no fish mortality upon exposure to seismic sources (Falk 
and Lawrence, 1973; Holliday et al., 1987; La Bella et al., 1996; 
Santulli et al., 1999; McCauley et al., 2000a,b, 2003; Bjarti, 2002; 
Thomsen, 2002; Hassel et al., 2003; Popper et al., 2005; Boeger et al., 
2006).
    An experiment of the effects of a single 700 in\3\ airgun was 
conducted in Lake Meade, Nevada (USGS, 1999). The data were used in an 
Environmental Assessment of the effects of a marine reflection survey 
of the Lake Meade

[[Page 68533]]

fault system by the National Park Service (Paulson et al., 1993, in 
USGS, 1999). The airgun was suspended 3.5 m (11.5 ft) above a school of 
threadfin shad in Lake Meade and was fired three successive times at a 
30 second interval. Neither surface inspection nor diver observations 
of the water column and bottom found any dead fish.
    For a proposed seismic survey in Southern California, USGS (1999) 
conducted a review of the literature on the effects of airguns on fish 
and fisheries. They reported a 1991 study of the Bay Area Fault system 
from the continental shelf to the Sacramento River, using a 10 airgun 
(5,828 in \3\) array. Brezzina and Associates were hired by USGS to 
monitor the effects of the surveys and concluded that airgun operations 
were not responsible for the death of any of the fish carcasses 
observed. They also concluded that the airgun profiling did not appear 
to alter the feeding behavior of sea lions, seals, or pelicans observed 
feeding during the seismic surveys.
    Some studies have reported, some equivocally, that mortality of 
fish, fish eggs, or larvae can occur close to seismic sources 
(Kostyuchenko, 1973; Dalen and Knutsen, 1986; Booman et al., 1996; 
Dalen et al., 1996). Some of the reports claimed seismic effects from 
treatments quite different from actual seismic survey sounds or even 
reasonable surrogates. However, Payne et al. (2009) reported no 
statistical differences in mortality/morbidity between control and 
exposed groups of capelin eggs or monkfish larvae. Saetre and Ona 
(1996) applied a `worst-case scenario' mathematical model to 
investigate the effects of seismic energy on fish eggs and larvae. They 
concluded that mortality rates caused by exposure to seismic surveys 
are so low, as compared to natural mortality rates, that the impact of 
seismic surveying on recruitment to a fish stock must be regarded as 
insignificant.
    Physiological Effects--Physiological effects refer to cellular and/
or biochemical responses of fish to acoustic stress. Such stress 
potentially could affect fish populations by increasing mortality or 
reducing reproductive success. Primary and secondary stress responses 
of fish after exposure to seismic survey sound appear to be temporary 
in all studies done to date (Sverdrup et al., 1994; Santulli et al., 
1999; McCauley et al., 2000a,b). The periods necessary for the 
biochemical changes to return to normal are variable and depend on 
numerous aspects of the biology of the species and of the sound 
stimulus.
    Behavioral Effects--Behavioral effects include changes in the 
distribution, migration, mating, and catchability of fish populations. 
Studies investigating the possible effects of sound (including seismic 
survey sound) on fish behavior have been conducted on both uncaged and 
caged individuals (e.g., Chapman and Hawkins, 1969; Pearson et al., 
1992; Santulli et al., 1999; Wardle et al., 2001; Hassel et al., 2003). 
Typically, in these studies fish exhibited a sharp startle response at 
the onset of a sound followed by habituation and a return to normal 
behavior after the sound ceased.
    The Minerals Management Service (MMS, 2005) assessed the effects of 
a proposed seismic survey in Cook Inlet. The seismic survey proposed 
using three vessels, each towing two four-airgun arrays ranging from 
24,580.6 to 40,967.7 cm \3\ (1,500 to 2,500 in \3\). MMS noted that the 
impact to fish populations in the survey area and adjacent waters would 
likely be very low and temporary. MMS also concluded that seismic 
surveys may displace the pelagic fishes from the area temporarily when 
airguns are in use. However, fishes displaced and avoiding the airgun 
noise are likely to backfill the survey area in minutes to hours after 
cessation of seismic testing. Fishes not dispersing from the airgun 
noise (e.g., demersal species) may startle and move short distances to 
avoid airgun emissions.
    In general, any adverse effects on fish behavior or fisheries 
attributable to seismic testing may depend on the species in question 
and the nature of the fishery (season, duration, fishing method). They 
may also depend on the age of the fish, its motivational state, its 
size, and numerous other factors that are difficult, if not impossible, 
to quantify at this point, given such limited data on effects of 
airguns on fish, particularly under realistic at-sea conditions.

Anticipated Effects on Invertebrates

    The existing body of information on the impacts of seismic survey 
sound on marine invertebrates is very limited. However, there is some 
unpublished and very limited evidence of the potential for adverse 
effects on invertebrates, thereby justifying further discussion and 
analysis of this issue. The three types of potential effects of 
exposure to seismic surveys on marine invertebrates are pathological, 
physiological, and behavioral. Based on the physical structure of their 
sensory organs, marine invertebrates appear to be specialized to 
respond to particle displacement components of an impinging sound field 
and not to the pressure component (Popper et al., 2001).
    The only information available on the impacts of seismic surveys on 
marine invertebrates involves studies of individuals; there have been 
no studies at the population scale. Thus, available information 
provides limited insight on possible real-world effects at the regional 
or ocean scale. The most important aspect of potential impacts concerns 
how exposure to seismic survey sound ultimately affects invertebrate 
populations and their viability, including availability to fisheries.
    Literature reviews of the effects of seismic and other underwater 
sound on invertebrates were provided by Moriyasu et al. (2004) and 
Payne et al. (2008). The following sections provide a synopsis of 
available information on the effects of exposure to seismic survey 
sound on species of decapod crustaceans and cephalopods, the two 
taxonomic groups of invertebrates on which most such studies have been 
conducted. The available information is from studies with variable 
degrees of scientific soundness and from anecdotal information. A more 
detailed review of the literature on the effects of seismic survey 
sound on invertebrates is provided in Appendix D of NSF/USGS's PEIS.
    Pathological Effects--In water, lethal and sub-lethal injury to 
organisms exposed to seismic survey sound appears to depend on at least 
two features of the sound source: (1) The received peak pressure; and 
(2) the time required for the pressure to rise and decay. Generally, as 
received pressure increases, the period for the pressure to rise and 
decay decreases, and the chance of acute pathological effects 
increases. For the type of airgun array planned for the proposed 
program, the pathological (mortality) zone for crustaceans and 
cephalopods is expected to be within a few meters of the seismic 
source, at most; however, very few specific data are available on 
levels of seismic signals that might damage these animals. This premise 
is based on the peak pressure and rise/decay time characteristics of 
seismic airgun arrays currently in use around the world.
    Some studies have suggested that seismic survey sound has a limited 
pathological impact on early developmental stages of crustaceans 
(Pearson et al., 1994; Christian et al., 2003; DFO, 2004). However, the 
impacts appear to be either temporary or insignificant compared to what 
occurs under natural conditions. Controlled field experiments on adult 
crustaceans

[[Page 68534]]

(Christian et al., 2003, 2004; DFO, 2004) and adult cephalopods 
(McCauley et al., 2000a,b) exposed to seismic survey sound have not 
resulted in any significant pathological impacts on the animals. It has 
been suggested that exposure to commercial seismic survey activities 
has injured giant squid (Guerra et al., 2004), but the article provides 
little evidence to support this claim. Tenera Environmental (2011b) 
reported that Norris and Mohl (1983, summarized in Mariyasu et al., 
2004) observed lethal effects in squid (Loligo vulgaris) at levels of 
246 to 252 dB after 3 to 11 minutes.
    Andre et al. (2011) exposed four species of cephalopods (Loligo 
vulgaris, Sepia officinalis, Octopus vulgaris, and Ilex coindetii), 
primarily cuttlefish, to two hours of continuous 50 to 400 Hz 
sinusoidal wave sweeps at 157+/-5 dB re 1 [micro]Pa while captive in 
relatively small tanks. They reported morphological and ultrastructural 
evidence of massive acoustic trauma (i.e., permanent and substantial 
alterations [lesions] of statocyst sensory hair cells) to the exposed 
animals that increased in severity with time, suggesting that 
cephalopods are particularly sensitive to low frequency sound. The 
received SPL was reported as 157+/-5 dB re 1 [micro]Pa, with peak 
levels at 175 dB re 1 [micro]Pa. As in the McCauley et al. (2003) paper 
on sensory hair cell damage in pink snapper as a result of exposure to 
seismic sound, the cephalopods were subjected to higher sound levels 
than they would be under natural conditions, and they were unable to 
swim away from the sound source.
    Physiological Effects--Physiological effects refer mainly to 
biochemical responses by marine invertebrates to acoustic stress. Such 
stress potentially could affect invertebrate populations by increasing 
mortality or reducing reproductive success. Primary and secondary 
stress responses (i.e., changes in haemolymph levels of enzymes, 
proteins, etc.) of crustaceans have been noted several days or months 
after exposure to seismic survey sounds (Payne et al., 2007). It was 
noted however, than no behavioral impacts were exhibited by crustaceans 
(Christian et al., 2003, 2004; DFO, 2004). The periods necessary for 
these biochemical changes to return to normal are variable and depend 
on numerous aspects of the biology of the species and of the sound 
stimulus.
    Behavioral Effects--There is increasing interest in assessing the 
possible direct and indirect effects of seismic and other sounds on 
invertebrate behavior, particularly in relation to the consequences for 
fisheries. Changes in behavior could potentially affect such aspects as 
reproductive success, distribution, susceptibility to predation, and 
catchability by fisheries. Studies investigating the possible 
behavioral effects of exposure to seismic survey sound on crustaceans 
and cephalopods have been conducted on both uncaged and caged animals. 
In some cases, invertebrates exhibited startle responses (e.g., squid 
in McCauley et al., 2000a,b). In other cases, no behavioral impacts 
were noted (e.g., crustaceans in Christian et al., 2003, 2004; DFO 
2004). There have been anecdotal reports of reduced catch rates of 
shrimp shortly after exposure to seismic surveys; however, other 
studies have not observed any significant changes in shrimp catch rate 
(Andriguetto-Filho et al., 2005). Similarly, Parry and Gason (2006) did 
not find any evidence that lobster catch rates were affected by seismic 
surveys. Any adverse effects on crustacean and cephalopod behavior or 
fisheries attributable to seismic survey sound depend on the species in 
question and the nature of the fishery (season, duration, fishing 
method). More information on the potential effects of airguns on fish 
and invertebrates are reviewed in section 3.2.4.3, section 3.3.4.3, and 
Appendix D of the NSF/USGS PEIS.

Proposed Mitigation

    In order to issue an Incidental Take Authorization (ITA) under 
section 101(a)(5)(D) of the MMPA, NMFS must set forth the permissible 
methods of taking pursuant to such activity, and other means of 
effecting the least practicable impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and the availability of such species or 
stock for taking for certain subsistence uses (where relevant).
    NSF and ASC reviewed the following source documents and have 
incorporated a suite of appropriate mitigation measures into their 
project description.
    (1) Protocols used during previous NSF and USGS-funded seismic 
research cruises as approved by NMFS and detailed in the ``Final 
Programmatic Environmental Impact Statement/Overseas Environmental 
Impact Statement for Marine Seismic Research Funded by the National 
Science Foundation or Conducted by the U.S. Geological Survey;''
    (2) Previous IHA applications and IHAs approved and authorized by 
NMFS; and
    (3) Recommended best practices in Richardson et al. (1995), Pierson 
et al. (1998), and Weir and Dolman, (2007).
    To reduce the potential for disturbance from acoustic stimuli 
associated with the activities, NSF, ASC, and their designees have 
proposed to implement the following mitigation measures for marine 
mammals:
    (1) Proposed exclusion zones around the sound source;
    (2) Speed and course alterations;
    (3) Shut-down procedures; and
    (4) Ramp-up procedures.
    Proposed Exclusion Zones--During pre-planning of the cruise, the 
smallest airgun array was identified that could be used and still meet 
the geophysical scientific objectives. NSF and ASC use radii to 
designate exclusion and buffer zones and to estimate take for marine 
mammals. Table 2 (presented earlier in this document) shows the 
distances at which one would expect to receive three sound levels (160, 
180, and 190 dB) from the two GI airgun array. The 180 and 190 dB level 
shut-down criteria are applicable to cetaceans and pinnipeds, 
respectively, as specified by NMFS (2000). NSF and ASC used these 
levels to establish the exclusion and buffer zones.
    Received sound levels have been modeled by L-DEO for a number of 
airgun configurations, including two 45 in\3\ Nucleus G airguns, in 
relation to distance and direction from the airguns (see Figure 2 of 
Appendix B of the IHA application). In addition, propagation 
measurements of pulses from two GI airguns have been reported for 
shallow water (approximately 30 m [98.4 ft] depth) in the GOM (Tolstoy 
et al., 2004). However, measurements were not made for the two GI 
airguns in deep water. The model does not allow for bottom 
interactions, and is most directly applicable to deep water. Based on 
the modeling, estimates of the maximum distances from the GI airguns 
where sound levels are predicted to be 190, 180, and 160 dB re 1 
[micro]Pa (rms) in intermediate water were determined (see Table 2 
above).
    Empirical data concerning the 190, 180, and 160 dB (rms) distances 
were acquired for various airgun arrays based on measurements during 
the acoustic verification studies conducted by L-DEO in the northern 
GOM in 2003 (Tolstoy et al., 2004) and 2007 to 2008 (Tolstoy et al., 
2009). Results of the 18 and 36 airgun arrays are not relevant for the 
two GI airguns to be used in the proposed low-energy seismic survey 
because the airgun arrays are not the same size or volume. The 
empirical data for the 6, 10, 12, and 20 airgun arrays indicate that, 
for deep water, the L-DEO

[[Page 68535]]

model tends to overestimate the received sound levels at a given 
distance (Tolstoy et al., 2004). Measurements were not made for the two 
GI airgun array in deep water; however, NSF and ASC propose to use the 
safety radii predicted by L-DEO's model for the proposed GI airgun 
operations in intermediate water, although they are likely conservative 
given the empirical results for the other arrays.
    Based on the modeling data, the outputs from the pair of 105 in\3\ 
GI airguns proposed to be used during the low-energy seismic survey are 
considered a low-energy acoustic source in the NSF/USGS PEIS (2011) for 
marine seismic research. A low-energy seismic source was defined in the 
NSF/USGS PEIS as an acoustic source whose received level at 100 m is 
less than 180 dB. The NSF/USGS PEIS also established for these low-
energy sources, a standard exclusion zone of 100 m for all low-energy 
sources in water depths greater than 100 m. This standard 100 m 
exclusion zone would be used during the proposed low-energy seismic 
survey. The 180 and 190 dB (rms) radii are shut-down criteria 
applicable to cetaceans and pinnipeds, respectively, as specified by 
NMFS (2000); these levels were used to establish exclusion zones. 
Therefore, the assumed 180 and 190 dB radii are 100 m for intermediate 
and deep water. If the PSO detects a marine mammal within or about to 
enter the appropriate exclusion zone, the airguns would be shut-down 
immediately.
    Speed and Course Alterations--If a marine mammal is detected 
outside the exclusion zone and, based on its position and direction of 
travel (relative motion), is likely to enter the exclusion zone, 
changes of the vessel's speed and/or direct course would be considered 
if this does not compromise operational safety or damage the deployed 
equipment. This would be done if operationally practicable while 
minimizing the effect on the planned science objectives. For marine 
seismic surveys towing large streamer arrays, course alterations are 
not typically implemented due to the vessel's limited maneuverability. 
However, the Palmer would be towing a relatively short hydrophone 
streamer, so its maneuverability during operations with the hydrophone 
streamer would not be limited as vessels towing long streamers, thus 
increasing the potential to implement course alterations, if necessary. 
After any such speed and/or course alteration is begun, the marine 
mammal activities and movements relative to the seismic vessel would be 
closely monitored to ensure that the marine mammal does not approach 
within the exclusion zone. If the marine mammal appears likely to enter 
the exclusion zone, further mitigation actions would be taken, 
including further speed and/or course alterations, and/or shut-down of 
the airgun(s). Typically, during seismic operations, the source vessel 
is unable to change speed or course, and one or more alternative 
mitigation measures would need to be implemented.
    Shut-down Procedures--If a marine mammal is detected outside the 
exclusion zone for the airgun(s) and the vessel's speed and/or course 
cannot be changed to avoid having the animal enter the exclusion zone, 
NSF and ASC would shut-down the operating airgun(s) before the animal 
is within the exclusion zone. Likewise, if a marine mammal is already 
within the exclusion zone when first detected, the seismic source would 
be shut-down immediately.
    Following a shut-down, NSF and ASC would not resume airgun activity 
until the marine mammal has cleared the exclusion zone. NSF and ASC 
would consider the animal to have cleared the exclusion zone if:
     A PSO has visually observed the animal leave the exclusion 
zone, or
     A PSO has not sighted the animal within the exclusion zone 
for 15 minutes for species with shorter dive durations (i.e., small 
odontocetes and pinnipeds), or 30 minutes for species with longer dive 
durations (i.e., mysticetes and large odontocetes, including sperm, 
killer, and beaked whales).
    Although power-down procedures are often standard operating 
practice for seismic surveys, they are not proposed to be used during 
this planned low-energy seismic survey because powering-down from two 
airguns to one airgun would make only a small difference in the 
exclusion zone(s) that probably would not be enough to allow continued 
one-airgun operations if a marine mammal came within the exclusion zone 
for two airguns.
    Ramp-up Procedures--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 of the 
airgun array 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, avoiding any potential injury or impairment 
of their hearing abilities. NSF and ASC would follow a ramp-up 
procedure when the airgun array begins operating after a specified 
period without airgun operations or when a shut-down has exceeded that 
period. NSF and ASC propose that, for the present cruise, this period 
would be approximately 15 minutes. SIO, L-DEO, and USGS have used 
similar periods (approximately 15 minutes) during previous low-energy 
seismic surveys.
    Ramp-up would begin with a single GI airgun (105 in\3\). The second 
GI airgun (105 in\3\) would be added after 5 minutes. During ramp-up, 
the PSOs would monitor the exclusion zone, and if marine mammals are 
sighted, a shut-down would be implemented as though both GI airguns 
were operational.
    If the complete exclusion zone has not been visible for at least 30 
minutes prior to the start of operations in either daylight or 
nighttime, NSF and ASC would not commence the ramp-up. Given these 
provisions, it is likely that the airgun array would not be ramped-up 
from a complete shut-down during low light conditions, at night, or in 
thick fog, because the outer part of the exclusion zone for that array 
would not be visible during those conditions. If one airgun has been 
operating, ramp-up to full power would be permissible during low light, 
at night, or in poor visibility, on the assumption that marine mammals 
would be alerted to the approaching seismic vessel by the sounds from 
the single airgun and could move away if they choose. NSF and ASC would 
not initiate a ramp-up of the airguns if a marine mammal is sighted 
within or near the applicable exclusion zones.

Proposed Mitigation Conclusions

    NMFS has carefully evaluated the applicant's proposed mitigation 
measures and has 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. NMFS's evaluation of potential measures included 
consideration of the following factors in relation to one another:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure is expected to minimize adverse impacts 
to marine mammals;
    (2) The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned; and
    (3) The practicability of the measure for applicant implementation.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the

[[Page 68536]]

accomplishment of one or more of the general goals listed below:
    (1) Avoidance of minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    (2) A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to received 
levels of airguns, or other activities expected to result in the take 
of marine mammals (this goal may contribute to 1, above, or to reducing 
harassment takes only).
    (3) A reduction in the number of time (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of airguns, or other activities expected to result 
in the take of marine mammals (this goal may contribute to 1, above, or 
to reducing harassment takes only).
    (4) A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of airguns, or other activities, or other activities expected to 
result in the take of marine mammals (this goal may contribute to a, 
above, or to reducing the severity of harassment takes only).
    (5) Avoidance or minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    (6) For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on NMFS's evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS or recommended by the public, 
NMFS has preliminarily 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.

Proposed Monitoring and Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for IHAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that would 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. NSF and ASC submitted a marine mammal monitoring plan as part of 
the IHA application. It can be found in Section 13 of the IHA 
application. The plan may be modified or supplemented based on comments 
or new information received from the public during the public comment 
period.
    Monitoring measures prescribed by NMFS should accomplish one or 
more of the following general goals:
    (1) An increase in the probability of detecting marine mammals, 
both within the mitigation zone (thus allowing for more effective 
implementation of the mitigation) and in general to generate more data 
to contribute to the analyses mentioned below;
    (2) An increase in our understanding of how many marine mammals are 
likely to be exposed to levels of sound (airguns) that we associate 
with specific adverse effects, such as behavioral harassment, TTS, or 
PTS;
    (3) An increase in our understanding of how marine mammals respond 
to stimuli expected to result in take and how anticipated adverse 
effects on individuals (in different ways and to varying degrees) may 
impact the population, species, or stock (specifically through effects 
on annual rates of recruitment or survival) through any of the 
following methods:
     Behavioral observations in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);
     Physiological measurements in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information); and
     Distribution and/or abundance comparisons in times or 
areas with concentrated stimuli versus times or areas without stimuli.
    (4) An increased knowledge of the affected species; and
    (5) An increase in our understanding of the effectiveness of 
certain mitigation and monitoring measures.

Proposed Monitoring

    NSF and ASC propose to sponsor marine mammal monitoring during the 
proposed project, in order to implement the proposed mitigation 
measures that require real-time monitoring and to satisfy the 
anticipated monitoring requirements of the IHA. NSF and ASC's proposed 
``Monitoring Plan'' is described below this section. NSF and ASC 
understand that this monitoring plan would be subject to review by NMFS 
and that refinements may be required. The monitoring work described 
here has been planned as a self-contained project independent of any 
other related monitoring projects that may be occurring simultaneously 
in the same regions. NSF and ASC is prepared to discuss coordination of 
their monitoring program with any related work that might be done by 
other groups insofar as this is practical and desirable.

Vessel-Based Visual Monitoring

    PSOs would be based aboard the seismic source vessel and would 
watch for marine mammals near the vessel during icebreaking activities, 
daytime airgun operations and during any ramp-ups of the airguns at 
night. PSOs would also watch for marine mammals near the seismic vessel 
for at least 30 minutes prior to the start of airgun operations and 
after an extended shut-down (i.e., greater than approximately 15 
minutes for this proposed low-energy seismic survey). When feasible, 
PSOs would conduct observations during daytime periods when the seismic 
system is not operating (such as during transits) for comparison of 
sighting rates and behavior with and without airgun operations and 
between acquisition periods. Based on PSO observations, the airguns 
would be shut-down when marine mammals are observed within or about to 
enter a designated exclusion zone. The exclusion zone is a region in 
which a possibility exists of adverse effects on animal hearing or 
other physical effects.
    During seismic operations in the Ross Sea, at least three PSOs 
would be based aboard the Palmer. At least one PSO would stand watch at 
all times while the Palmer is operating airguns during the proposed 
low-energy seismic survey; this procedure would also be followed when 
the vessel is in transit and conducting icebreaking. NSF and ASC would 
appoint the PSOs with NMFS's concurrence. The lead PSO would be 
experienced with marine mammal species in the Ross Sea and/or Southern 
Ocean, the second and third PSOs would receive additional specialized 
training from the lead PSO to ensure that they can identify marine 
mammal species commonly found in the Ross Sea and Southern Ocean. 
Observations would take place during ongoing daytime operations and 
ramp-ups of the airguns. During the majority

[[Page 68537]]

of seismic operations, at least one PSO would be on duty from 
observation platforms (i.e., the best available vantage point on the 
source vessel) to monitor marine mammals near the seismic vessel. 
PSO(s) would be on duty in shifts no longer than 4 hours in duration. 
Other crew would also be instructed to assist in detecting marine 
mammals and implementing mitigation requirements (if practical). Before 
the start of the low-energy seismic survey, the crew would be given 
additional instruction on how to do so.
    The Palmer is a suitable platform for marine mammal observations 
and would serve as the platform from which PSOs would watch for marine 
mammals before and during seismic operations. Two locations are likely 
as observation stations onboard the Palmer. One observing station is 
located on the bridge level, with the PSO eye level at approximately 
16.5 m (54.1 ft) above the waterline and the PSO would have a good view 
around the entire vessel. In addition, there is an aloft observation 
tower for the PSO approximately 24.4 m (80.1 ft) above the waterline 
that is protected from the weather, and affords PSOs an even greater 
view. The approximate view around the vessel from the bridge is 
270[deg] and from the aloft observation tower is 360[deg].
    Standard equipment for PSOs would be reticle binoculars. Night-
vision equipment would not be available or necessary as there would be 
24-hour daylight or nautical twilight during the cruise. The PSOs would 
be in communication with ship's officers on the bridge and scientists 
in the vessel's operations laboratory, so they can advise promptly of 
the need for avoidance maneuvers or seismic source shut-down. During 
daylight, the PSO(s) would scan the area around the vessel 
systematically with reticle binoculars (e.g., 7 x 50 Fujinon FMTRC-SX) 
and the naked eye. These binoculars would have a built-in daylight 
compass. Estimating distances is done primarily with the reticles in 
the binoculars. The PSO(s) would be in direct (radio) wireless 
communication with ship's officers on the bridge and scientists in the 
vessel's operations laboratory during seismic operations, so they can 
advise the vessel operator, science support personnel, and the science 
party promptly of the need for avoidance maneuvers or a shut-down of 
the seismic source. PSOs would monitor for the presence pinnipeds and 
cetaceans during icebreaking activities, and would be limited to those 
marine mammal species in proximity to the ice margin habitat. 
Observations within the buffer zone would also include pinnipeds that 
may be present on the surface of the sea ice (i.e., hauled-out) and 
that could potentially dive into the water as the vessel approaches, 
indicating disturbance from noise generated by icebreaking activities).
    When a marine mammal is detected within or about to enter the 
designated exclusion zone, the airguns would immediately be shut-down, 
unless the vessel's speed and/or course can be changed to avoid having 
the animal enter the exclusion zone. The PSO(s) would continue to 
maintain watch to determine when the animal is outside the exclusion 
zone by visual confirmation. Airgun operations would not resume until 
the animal is confirmed to have left the exclusion zone, or is not 
observed after 15 minutes for species with shorter dive durations 
(small odontocetes and pinnipeds) or 30 minutes for species with longer 
dive durations (mysticetes and large odontocetes, including sperm, 
killer, and beaked whales).

PSO Data and Documentation

    PSOs would record data to estimate the numbers of marine mammals 
exposed to various received sound levels and to document apparent 
disturbance reactions or lack thereof. Data would be used to estimate 
numbers of animals potentially ``taken'' by harassment (as defined in 
the MMPA). They would also provide information needed to order a shut-
down of the airguns when a marine mammal is within or near the 
exclusion zone. Observations would also be made during icebreaking 
activities as well as daylight periods when the Palmer is underway 
without seismic airgun operations (i.e., transits to, from, and through 
the study area) to collect baseline biological data.
    When a sighting is made, the following information about the 
sighting would be recorded:
    1. Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from seismic vessel, sighting cue, 
apparent reaction to the seismic source or vessel (e.g., none, 
avoidance, approach, paralleling, etc.), and behavioral pace.
    2. Time, location, heading, speed, activity of the vessel 
(including number of airguns operating and whether in state of ramp-up 
or shut-down), sea state, wind force, visibility, and sun glare.
    The data listed under (2) would also be recorded at the start and 
end of each observation watch, and during a watch whenever there is a 
change in one or more of the variables.
    All observations, as well as information regarding ramp-ups or 
shut-downs would be recorded in a standardized format. Data would be 
entered into an electronic database. The data accuracy would be 
verified by computerized data validity checks as the data are entered 
and by subsequent manual checking of the database by the PSOs at sea. 
These procedures would allow initial summaries of data to be prepared 
during and shortly after the field program, and would facilitate 
transfer of the data to statistical, graphical, and other programs for 
further processing and archiving.
    Results from the vessel-based observations would provide the 
following information:
    1. The basis for real-time mitigation (airgun shut-down).
    2. Information needed to estimate the number of marine mammals 
potentially taken by harassment, which must be reported to NMFS.
    3. Data on the occurrence, distribution, and activities of marine 
mammals in the area where the seismic study is conducted.
    4. Information to compare the distance and distribution of marine 
mammals relative to the source vessel at times with and without airgun 
operations and icebreaking activities.
    5. Data on the behavior and movement patterns of marine mammals 
seen at times with and without airgun operations and icebreaking 
activities.

Proposed Reporting

    NSF and ASC would submit a comprehensive report to NMFS within 90 
days after the end of the cruise. The report would describe the 
operations that were conducted and sightings of marine mammals near the 
operations. The report submitted to NMFS would provide full 
documentation of methods, results, and interpretation pertaining to all 
monitoring. The 90-day report would summarize the dates and locations 
of seismic operations and all marine mammal sightings (i.e., dates, 
times, locations, activities, and associated seismic survey 
activities). The report would include, at a minimum:
     Summaries of monitoring effort--total hours, total 
distances, and distribution of marine mammals through the study period 
accounting for Beaufort sea state and other factors affecting 
visibility and detectability of marine mammals;
     Analyses of the effects of various factors influencing 
detectability of marine mammals including Beaufort sea state, number of 
PSOs, and fog/glare;

[[Page 68538]]

     Species composition, occurrence, and distribution of 
marine mammals sightings including date, water depth, numbers, age/
size/gender, and group sizes, and analyses of the effects of airgun 
operations and icebreaking activities;
     Sighting rates of marine mammals during periods with and 
without airgun operations and icebreaking activities (and other 
variables that could affect detectability);
     Initial sighting distances versus airgun operations and 
icebreaking activity state;
     Closest point of approach versus airgun operations and 
icebreaking activity state;
     Observed behaviors and types of movements versus airgun 
operations and icebreaking activity state;
     Numbers of sightings/individuals seen versus airgun 
operations and icebreaking activity state; and
     Distribution around the source vessel versus airgun 
operations and icebreaking activity state.
    The report would also include estimates of the number and nature of 
exposures that could result in ``takes'' of marine mammals by 
harassment or in other ways. NMFS would review the draft report and 
provide any comments it may have, and NSF and ASC would incorporate 
NMFS's comments and prepare a final report. After the report is 
considered final, it would be publicly available on the NMFS Web site 
at: https://www.nmfs.noaa.gov/pr/permits/incidental/.
    Reporting Prohibited Take--In the unanticipated event that the 
specified activity clearly causes the take of a marine mammal in a 
manner prohibited by this IHA, such as an injury (Level A harassment), 
serious injury or mortality (e.g., ship-strike, gear interaction, and/
or entanglement), NSF and ASC would immediately cease the specified 
activities and immediately report the incident to the Chief of the 
Permits and Conservation Division, Office of Protected Resources, NMFS 
at 301-427-8401 and/or by email to Jolie.Harrison@noaa.gov and 
Howard.Goldstein@noaa.gov. The report must include the following 
information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with NSF and ASC 
to determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. NSF and ASC may not resume 
their activities until notified by NMFS via letter or email, or 
telephone.
    Reporting an Injured or Dead Marine Mammal with an Unknown Cause of 
Death--In the event that NSF and ASC discover 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), NSF and ASC shall immediately 
report the incident to the Chief of the Permits and Conservation 
Division, Office of Protected Resources, NMFS, at 301-427-8401, and/or 
by email to Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov. The 
report must include the same information identified in the paragraph 
above. Activities may continue while NMFS reviews the circumstances of 
the incident. NMFS shall work with NSF and ASC to determine whether 
modifications in the activities are appropriate.
    Reporting an Injured or Dead Marine Mammal Not Related to the 
Activities--In the event that NSF and ASC discover 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 
(e.g., previously wounded animal, carcass with moderate or advanced 
decomposition, or scavenger damage), NSF and ASC shall report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, at 301-427-8401, and/or by email to 
Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov, within 24 hours 
of discovery. NSF and ASC shall provide photographs or video footage 
(if available) or other documentation of the stranded animal sighting 
to NMFS. Activities may continue while NMFS reviews the circumstances 
of the incident.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

      Table 5--NMFS's Current Underwater Acoustic Exposure Criteria
------------------------------------------------------------------------
                     Impulsive (non-explosive) sound
-------------------------------------------------------------------------
          Criterion           Criterion definition        Threshold
------------------------------------------------------------------------
Level A harassment (injury).  Permanent threshold   180 dB re 1
                               shift (PTS) (Any      [micro]Pa-m (root
                               level above that      means square [rms])
                               which is known to     (cetaceans).
                               cause TTS).          190 dB re 1
                                                     [micro]Pa-m (rms)
                                                     (pinnipeds).
Level B harassment..........  Behavioral            160 dB re 1
                               disruption (for       [micro]Pa-m (rms).
                               impulsive noise).
Level B harassment..........  Behavioral            120 dB re 1
                               disruption (for       [micro]Pa-m (rms).
                               continuous noise).
------------------------------------------------------------------------

    Level B harassment is anticipated and proposed to be authorized as 
a result of the proposed low-energy seismic survey in the Ross Sea. 
Acoustic stimuli (i.e., increased underwater sound) generated during 
the operation of the seismic airgun array and icebreaking activities 
are expected to result in the behavioral disturbance of some marine 
mammals. There is no evidence that the planned activities for which NSF 
and ASC seek the IHA could result in injury, serious injury, or 
mortality. The required mitigation and monitoring measures

[[Page 68539]]

would minimize any potential risk for injury, serious injury, or 
mortality.
    The following sections describe NSF and ASC's methods to estimate 
take by incidental harassment and present the applicant's estimates of 
the numbers of marine mammals that could be affected during the 
proposed low-energy seismic survey in the Ross Sea. The estimates are 
based on a consideration of the number of marine mammals that could be 
harassed during the approximately 200 hours and 1,750 km of seismic 
airgun operations with the two GI airgun array to be used and 500 km of 
icebreaking activities.
    During simultaneous operations of the airgun array and the other 
sound sources, any marine mammals close enough to be affected by the 
single and multi-beam echosounders, ADCP, or sub-bottom profiler would 
already be affected by the airguns. During times when the airguns are 
not operating, it is unlikely that marine mammals would exhibit more 
than minor, short-term responses to the echosounders, ADCPs, and sub-
bottom profiler given their characteristics (e.g., narrow, downward-
directed beam) and other considerations described previously. 
Therefore, for this activity, take was not authorized specifically for 
these sound sources beyond that which is already proposed to be 
authorized for airguns and icebreaking activities.
    There are no stock assessments and very limited population 
information available for marine mammals in the Ross Sea. Published 
estimates of marine mammal densities are limited for the proposed low-
energy seismic survey's action area. Available density estimates (using 
number of animals per km\2\) from the Naval Marine Species Density 
Database (NMSDD) (NAVFAC, 2012) were used for one mysticete and one 
odontocete (i.e., sei whale and Arnoux's beaked whale). Densities for 
minke (including the dwarf sub-species) whales were unavailable and the 
densities for Antarctic minke whales were used as proxies, 
respectively.
    For other mysticetes and odontocetes, reported sightings data from 
one previous research survey (i.e., International Whaling Commission 
Southern Ocean Whale and Ecosystem Research [IWC SOWER]) in the Ross 
Sea and vicinity were used to identify species that may be present in 
the proposed action area and to estimate densities. Available sightings 
data from the 2002 to 2003 IWC SOWER Circumpolar Cruise, Area V (Ensor 
et al., 2003) were used to estimate densities for five mysticetes 
(i.e., humpback, Antarctic minke, minke, fin, and blue whale) and six 
odontocetes (i.e., sperm, southern bottlenose, strap-toothed beaked, 
killer, long-finned pilot whale and hourglass dolphin). Densities of 
pinnipeds (i.e., crabeater, leopard, Ross, Weddell, and southern 
elephant seal) were estimated using data from two surveys (NZAI, 2001; 
Pinkerton and Bradford-Grieve, n.d.) and dividing the estimated 
population of animals by the area of the Ross Sea (approximately 
300,000 km\2\ [87,466 nmi\2\]). While these surveys were not 
specifically designed to quantify marine mammal densities, there was 
sufficient information to develop density estimates.
    The densities used for purposes of estimating potential take do not 
take into account the patchy distributions of marine mammals in an 
ecosystem, at least on the moderate to fine scales over which they are 
known to occur. Instead, animals are considered evenly distributed 
throughout the assessed study area and seasonal movement patterns are 
not taken into account as none are available.
    Some marine mammals that were present in the area during these 
surveys may not have been observed. Southwell et al. (2008) suggested a 
20 to 40% sighting factor for pinnipeds, and the most conservative 
value from Southwell et al. (2008) was applied for cetaceans. 
Therefore, the estimated frequency of sightings data in this proposed 
IHA for cetaceans incorporates a correction factor of 5, which assumes 
only 20% of the animals present were reported due to sea and other 
environmental conditions that may have hindered observation, and 
therefore, there were 5 times more cetaceans actually present. The 
correction factor (20%) was intended to conservatively account for 
unobserved (i.e., not sighted and reported) animals.
    The pinnipeds that may be present in the study area during the 
proposed action and are expected to be observed occur mostly near pack 
ice, coastal areas, and rocky habitats on the shelf, and are not 
prevalent in open sea areas where the low-energy seismic survey would 
be conducted. Because density estimates for pinnipeds in the sub-
Antarctic and Antarctic regions typically represent individuals that 
have hauled-out of the water, those estimates are not necessarily 
representative of individuals that are in the water and could be 
potentially exposed to underwater sounds during the seismic airgun 
operations and icebreaking activities; therefore, the pinniped 
densities have been adjusted downward to account for this 
consideration. Take was not requested for Antarctic and Subantarctic 
seals because preferred habitat for these species is not within the 
proposed action area. Although there is some uncertainty about the 
representativeness of the data and the assumptions used in the 
calculations below, the approach used here is believed to be the best 
available approach, using the best available science.

 Table 6--Estimated Densities and Possible Number of Marine Mammal Species That Might Be Exposed to Greater Than or Equal to 160 dB (Airgun Operations)
     and 120 dB (Icebreaking) During NSF and ASC's Proposed Low-Energy Seismic Survey (Approximately 500 km of Tracklines/Approximately 21,540 km\2\
 Ensonified Area for Icebreaking Activities and Approximately 1,750 km of Tracklines/Approximately 3,882 km\2\ [1.109 km x 2 x 1,750 km] Ensonified Area
                                            for Airgun Operations) in the Ross Sea, January to February 2015
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Calculated      Calculated
                                                   take from       take from
                                                seismic airgun    icebreaking
                                                   operations     operations
                                                    (i.e.,          (i.e.,                                             Approximate
                                    Density        estimated       estimated    Total requested                       percentage of
            Species               (number of       number of       number of          take         Abundance \3\        population      Population trend
                                animals/km\2\)    individuals     individuals    authorization                           estimate             \5\
                                      \1\         exposed to      exposed to                                         (requested take)
                                                 sound levels    sound levels                                              \4\
                                                 >= 160 dB re    >= 120 dB re
                                                 1 [micro]Pa)    1 [micro]Pa)
                                                      \2\             \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
Southern right whale..........              NA               0               0                0  8,000 to 15,000..  NA...............  Increasing at 7
                                                                                                                                        to 8% per year.

[[Page 68540]]

 
Humpback whale................       0.0321169             125             692              817  35,000 to 40,000-- 0.03--Worldwide..  Increasing.
                                                                                                  Worldwide.        9.88--Scotia Sea
                                                                                                 9,484--Scotia Sea   and Antarctic
                                                                                                  and Antarctica     Peninsula.
                                                                                                  Peninsula.
Antarctic minke whale.........       0.0845595             329           1,822            2,151  Several 100,000--  11.87--Scotia Sea  Stable.
                                                                                                  Worldwide.         and Antarctica
                                                                                                 18,125--Scotia      Peninsula.
                                                                                                  Sea and
                                                                                                  Antarctica
                                                                                                  Peninsula.
Minke whale (including dwarf           0.08455             329           1,822            2,151  NA...............  NA...............  NA.
 minke whale sub-species).
Sei whale.....................       0.0046340              18             100              118  80,000--Worldwide  0.15.............  NA.
Fin whale.....................       0.0306570             120             661              781  140,000--Worldwid  0.56--Worldwide..  NA.
                                                                                                  e.                16.72--Scotia Sea
                                                                                                 4,672--Scotia Sea   and Antarctica
                                                                                                  and Antarctica     Peninsula.
                                                                                                  Peninsula.
Blue whale....................       0.0065132              26             141              167  8,000 to 9,000--   2.09--Worldwide..  NA.
                                                                                                  Worldwide.        9.82--Southern
                                                                                                 1,700--Southern     Ocean.
                                                                                                  Ocean.
Odontocetes:
Sperm whale...................       0.0098821              39             213              252  360,000--Worldwid  0.07--Worldwide..  NA.
                                                                                                  e.                2.65--Antarctic..
                                                                                                 9,500--Antarctic.
Arnoux's beaked whale.........       0.0134420              53             290              343  NA...............  NA...............  NA.
Strap-toothed beaked whale....       0.0044919              18              97              115  NA...............  NA...............  NA.
Southern bottlenose whale.....       0.0117912              46             254              300  50,000--South of   0.6..............  NA.
                                                                                                  Antarctic
                                                                                                  Convergence.
Killer whale..................       0.0208872              82             450              532  80,000--South of   0.67--South of     NA.
                                                                                                  Antarctic          Antarctic
                                                                                                  Convergence.       Convergence.
                                                                                                 25,000--Southern   2.13--Southern
                                                                                                  Ocean.             Ocean.
Long-finned pilot whale.......       0.0399777             156             862            1,018  200,000--South of  0.51.............  NA.
                                                                                                  Antarctic
                                                                                                  Convergence.
Hourglass dolphin.............       0.0189782              74             409              483  144,000--South of  0.34.............  NA.
                                                                                                  Antarctic
                                                                                                  Convergence.
Pinnipeds:
Crabeater seal................       0.6800000           2,640          14,648           17,288  5,000,000 to       0.35.............  Increasing.
                                                                                                  15,000,000--Worl
                                                                                                  dwide.
Leopard seal..................       0.0266700             104             575              679  220,000 to         0.31.............  NA.
                                                                                                  440,000--Worldwi
                                                                                                  de.
Ross seal.....................       0.0166700              65             360              425  130,000..........  2.13.............  NA.
                                                                                                 20,000 to
                                                                                                  220,000--Worldwi
                                                                                                  de.
Weddell seal..................       0.1066700             415           2,298            2,713  500,000 to         0.54.............  NA.
                                                                                                  1,000,000--World
                                                                                                  wide.
Southern elephant seal........       0.0001300               1               3                4  640,000 to         <0.01--Worldwide   Increasing,
                                                                                                  650,000--Worldwi   or South Georgia   decreasing, or
                                                                                                  de;.               Island.            stable depending
                                                                                                 470,000--South                         on breeding
                                                                                                  Georgia Island.                       population.
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ Densities based on sightings from IWC SOWER Report 2002, NMSDD, or State of the Ross Sea Region (NZAI, 2001) data.
\2\ Calculated take is estimated density (reported density times correction factor) multiplied by the area ensonified to 160 dB (rms) around the planned
  seismic lines, increased by 25% for contingency.
\3\ Calculated take is estimated density (reported density times correction factor) multiplied by the area ensonified to 120 dB (rms) around the planned
  transit lines where icebreaking activities may occur.
\3\ See population estimates for marine mammal species in Table 4 (above).
\4\ Total requested authorized takes expressed as percentages of the species or regional populations.
\5\ Jefferson et al. (2008).


[[Page 68541]]

    Icebreaking in Antarctic waters would occur, as necessary, between 
the latitudes of approximately 76 to 78[deg] South and between 165 and 
170[deg] West. Based on a historical sea ice extent and the proposed 
tracklines, it is estimated that the Palmer would actively break ice up 
to a distance of 500 km. Based on the ship's speed of 5 kts under 
moderate ice conditions, this distance represents approximately 54 
hours of icebreaking activities. This calculation is likely an 
overestimation because icebreakers often follow leads when they are 
available and thus do not break ice at all times. The estimated number 
of takes for pinnipeds accounts for both animals that may be in the 
water and those hauled-out on ice surfaces. While the number of 
cetaceans that may be encountered within the ice margin habitat would 
be expected to be less than open water, the estimates utilize densities 
for open water and therefore represent conservative estimates.
    Numbers of marine mammals that might be present and potentially 
disturbed are estimated based on the available data about marine mammal 
distribution and densities in the proposed Ross Sea study area. NSF and 
ASC estimated the number of different individuals that may be exposed 
to airgun sounds with received levels greater than or equal to 160 dB 
re 1 [mu]Pa (rms) for seismic airgun operations and greater than or 
equal to 120 dB re 1 [mu]Pa (rms) for icebreaking activities on one or 
more occasions by considering the total marine area that would be 
within the 160 dB radius around the operating airgun array and 120 dB 
radius for icebreaking activities on at least one occasion and the 
expected density of marine mammals in the area (in the absence of the a 
seismic survey and icebreaking activities). The number of possible 
exposures can be estimated by considering the total marine area that 
would be within the 160 dB radius (the diameter is 1,109 m multiplied 
by 2) around the operating airguns. The ensonified area for icebreaking 
was estimated by multiplying the distance of the icebreaking activities 
(500 km) by the estimated diameter for the area within the 120 dB 
radius (i.e., diameter is 43.08 km [21.54 km x 2]). The 160 dB radii 
are based on acoustic modeling data for the airguns that may be used 
during the proposed action (see Attachment B of the IHA application). 
As summarized in Table 2 (see above and Table 8 of the IHA 
application), the modeling results for the proposed low-energy seismic 
airgun array indicate the received levels are dependent on water depth. 
Since the majority of the proposed airgun operations would be conducted 
in waters 100 to 1,000 m deep, the buffer zone of 1,109 m for the two 
105 in\3\ GI airguns was used.
    The number of different individuals potentially exposed to received 
levels greater than or equal to 160 dB re 1 [mu]Pa (rms) from seismic 
airgun operations and 120 dB re 1 [mu]Pa (rms) for icebreaking 
activities was calculated by multiplying:
    (1) The expected species density (in number/km\2\), times
    (2) The anticipated area to be ensonified to that level during 
airgun operations and icebreaking activities.
    Applying the approach described above, approximately 3,882 km\2\ 
(including the 25% contingency) would be ensonified within the 160 dB 
isopleth for seismic airgun operations and approximately 21,540 km\2\ 
would be ensonified within the 120 dB isopleth for icebreaking 
activities on one or more occasions during the proposed low-energy 
seismic survey. The take calculations within the study sites do not 
explicitly add animals to account for the fact that new animals (i.e., 
turnover) not accounted for in the initial density snapshot could also 
approach and enter the area ensonified above 160 dB for seismic airgun 
operations and 120 dB for icebreaking activities. However, studies 
suggest that many marine mammals would avoid exposing themselves to 
sounds at this level, which suggests that there would not necessarily 
be a large number of new animals entering the area once the seismic 
survey and icebreaking activities started. Because this approach for 
calculating take estimates does not account for turnover in the marine 
mammal populations in the area during the course of the proposed low-
energy seismic survey, the actual number of individuals exposed may be 
underestimated. However, any underestimation is likely offset by the 
conservative (i.e., probably overestimated) line-kilometer distances 
(including the 25% contingency) used to calculate the survey area, and 
the fact the approach assumes that no cetaceans or pinnipeds would move 
away or toward the tracklines as the Palmer approaches in response to 
increasing sound levels before the levels reach 160 dB for seismic 
airgun operations and 120 dB for icebreaking activities, which is 
likely to occur and which would decrease the density of marine mammals 
in the survey area. Another way of interpreting the estimates in Table 
6 is that they represent the number of individuals that would be 
expected (in absence of a seismic and icebreaking program) to occur in 
the waters that would be exposed to greater than or equal to 160 dB 
(rms) for seismic airgun operations and greater than or equal to 120 dB 
(rms) for icebreaking activities.
    NSF and ASC's estimates of exposures to various sound levels assume 
that the proposed seismic survey would be carried out in full; however, 
the ensonified areas calculated using the planned number of line-
kilometers has been increased by 25% to accommodate lines that may need 
to be repeated, equipment testing, etc. As is typical during offshore 
ship surveys, inclement weather and equipment malfunctions would be 
likely to cause delays and may limit the number of useful line-
kilometers of seismic operations that can be undertaken. The estimates 
of the numbers of marine mammals potentially exposed to 160 dB (rms) 
received levels are precautionary and probably overestimate the actual 
numbers of marine mammals that could be involved. These estimates 
assume that there would be no weather, equipment, or mitigation delays 
that limit the seismic operations, which is highly unlikely.
    Table 6 shows the estimates of the number of different individual 
marine mammals anticipated to be exposed to greater than or equal to 
120 dB re 1 [mu]Pa (rms) for icebreaking activities and greater than or 
equal to 160 dB re 1 [mu]Pa (rms) for seismic airgun operations during 
the low-energy seismic survey if no animals moved away from the survey 
vessel. The total requested take authorization is given in the column 
that is fifth from the left) of Table 6.

Encouraging and Coordinating Research

    NSF and ASC would coordinate the planned marine mammal monitoring 
program associated with the proposed low-energy seismic survey with 
other parties that express interest in this activity and area. NSF and 
ASC would coordinate with applicable U.S. agencies (e.g., NMFS), and 
would comply with their requirements. The proposed action would 
complement fieldwork studying other Antarctic ice shelves, 
oceanographic studies, and ongoing development of ice sheet and

[[Page 68542]]

other ocean models. It would facilitate learning at sea and ashore by 
students, help to fill important spatial and temporal gaps in a lightly 
sampled region of the Ross Sea, provide additional data on marine 
mammals present in the Ross Sea study areas, and communicate its 
findings concerning the chronology and cause of eastern Ross Sea 
grounding-line translations during the last glacial cycle via reports, 
publications, and public outreach.

Impact on Availability of Affected Species or Stock for Taking for 
Subsistence Uses

    Section 101(a)(5)(D) of the MMPA also requires NMFS to determine 
that the authorization would not have an unmitigable adverse effect on 
the availability of marine mammal species or stocks for subsistence 
use. There are no relevant subsistence uses of marine mammals 
implicated by this action (in the Ross Sea study area). Therefore, NMFS 
has determined that the total taking of affected species or stocks 
would not have an unmitigable adverse impact on the availability of 
such species or stocks for taking for subsistence purposes.

Analysis and Preliminary Determinations

Negligible Impact

    Negligible impact is ``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'' (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes, 
alone, is not enough information on which to base an impact 
determination. In addition to considering estimates of the number of 
marine mammals that might be ``taken'' through behavioral harassment, 
NMFS must consider other factors, such as the likely nature of any 
responses (their intensity, duration, etc.) and the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A harassment takes, 
the number of estimated mortalities, effects on habitat, and the status 
of the species.
    In making a negligible impact determination, NMFS evaluated factors 
such as:
    (1) The number of anticipated serious injuries and or mortalities;
    (2) The number and nature of anticipated injuries;
    (3) The number, nature, intensity, and duration of takes by Level B 
harassment (all of which are relatively limited in this case);
    (4) The context in which the takes occur (e.g., impacts to areas of 
significance, impacts to local populations, and cumulative impacts when 
taking into account successive/contemporaneous actions when added to 
baseline data);
    (5) The status of stock or species of marine mammals (i.e., 
depleted, not depleted, decreasing, increasing, stable, impact relative 
to the size of the population);
    (6) Impacts on habitat affecting rates of recruitment/survival; and
    (7) The effectiveness of monitoring and mitigation measures.
    NMFS has preliminarily determined that the specified activities 
associated with the marine seismic survey are not likely to cause PTS, 
or other non-auditory injury, serious injury, or death, based on the 
analysis above and the following factors:
    (1) The likelihood that, given sufficient notice through relatively 
slow ship speed, marine mammals are expected to move away from a noise 
source that is annoying prior to its becoming potentially injurious;
    (2) The availability of alternate areas of similar habitat value 
for marine mammals to temporarily vacate the survey area during the 
operation of the airgun(s) to avoid acoustic harassment;
    (3) The potential for temporary or permanent hearing impairment is 
relatively low and would likely be avoided through the implementation 
of the required monitoring and mitigation measures (including shut-down 
measures); and
    (4) The likelihood that marine mammal detection ability by trained 
PSOs is high at close proximity to the vessel.
    No injuries, serious injuries, or mortalities are anticipated to 
occur as a result of the NSF and ASC's planned low-energy seismic 
survey, and none are proposed to be authorized by NMFS. Table 6 of this 
document outlines the number of requested Level B harassment takes that 
are anticipated as a result of these activities. Due to the nature, 
degree, and context of Level B (behavioral) harassment anticipated and 
described in this notice (see ``Potential Effects on Marine Mammals'' 
section above), the activity is not expected to impact rates of annual 
recruitment or survival for any affected species or stock, particularly 
given NMFS's and the applicant's proposed mitigation, monitoring, and 
reporting measures to minimize impacts to marine mammals. Additionally, 
the low-energy seismic survey would not adversely impact marine mammal 
habitat.
    For the marine mammal species that may occur within the proposed 
action area, there are no known designated or important feeding and/or 
reproductive areas. Many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (i.e., 24 
hr cycle). Behavioral reactions to noise exposure (such as disruption 
of critical life functions, displacement, or avoidance of important 
habitat) are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). While 
airgun operations are anticipated to occur on consecutive days, the 
estimated duration of the survey would not last more than a total of 
approximately 27 operational days. Additionally, the low-energy seismic 
survey would be increasing sound levels in the marine environment in a 
relatively small area surrounding the vessel (compared to the range of 
the animals), which is constantly travelling over distances, so 
individual animals likely would only be exposed to and harassed by 
sound for less than a day.
    As mentioned previously, NMFS estimates that 18 species of marine 
mammals under its jurisdiction could be potentially affected by Level B 
harassment over the course of the IHA. The population estimates for the 
marine mammal species that may be taken by Level B harassment were 
provided in Table 4 and 6 of this document. As shown in those tables, 
the proposed takes all represent small proportions of the overall 
populations of these marine mammal species (i.e., all are less than or 
equal to 16%).
    Of the 18 marine mammal species under NMFS jurisdiction that may or 
are known to likely occur in the study area, six are listed as 
threatened or endangered under the ESA: Southern right, humpback, sei, 
fin, blue, and sperm whales. These species are also considered depleted 
under the MMPA. None of the other marine mammal species that may be 
taken are listed as depleted under the MMPA. Of the ESA-listed species, 
incidental take has been requested to be authorized for five species. 
No incidental take has been requested for the southern right whale as 
they are generally not expected in the proposed action area; however, a 
few animals have been sighted in Antarctic waters in the austral 
summer. To protect these marine mammals in the study area, NSF and ASC 
would be required to cease airgun operations if any marine

[[Page 68543]]

mammal enters designated exclusion zones. No injury, serious injury, or 
mortality is expected to occur for any of these species, and due to the 
nature, degree, and context of the Level B harassment anticipated, and 
the activity is not expected to impact rates of recruitment or survival 
for any of these species.
    NMFS's practice has been to apply the 160 dB re 1 [mu]Pa (rms) 
received level threshold for underwater impulse sound levels to 
determine whether take by Level B harassment occurs. NMFS has 
preliminarily determined that, provided that the aforementioned 
mitigation and monitoring measures are implemented, the impact of 
conducting a low-energy marine seismic survey in the Ross Sea, January 
to February 2015, may result, at worst, in a modification in behavior 
and/or low-level physiological effects (Level B harassment) of certain 
species of marine mammals.
    While behavioral modifications, including temporarily vacating the 
area during the operation of the airgun(s), may be made by these 
species to avoid the resultant acoustic disturbance, the availability 
of alternate areas for species to move to and the short and sporadic 
duration of the research activities, have led NMFS to preliminary 
determine that the taking by Level B harassment from the specified 
activity would have a negligible impact on the affected species in the 
specified geographic region. Due to the nature, degree, and context of 
Level B (behavioral) harassment anticipated and described (see 
``Potential Effects on Marine Mammals'' section above) in this notice, 
the proposed activity is not expected to impact rates of annual 
recruitment or survival for any affected species or stock, particularly 
given the NMFS and applicant's proposal to implement mitigation and 
monitoring measures would minimize impacts to marine mammals. 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 proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from NSF and ASC's proposed low-energy seismic survey would 
have a negligible impact on the affected marine mammal species or 
stocks.

Small Numbers

    As mentioned previously, NMFS estimates that 18 species of marine 
mammals under its jurisdiction could be potentially affected by Level B 
harassment over the course of the IHA. The population estimates for the 
marine mammal species that may be taken by Level B harassment were 
provided in Tables 4 and 6 of this document.
    The estimated numbers of individual cetaceans and pinnipeds that 
could be exposed to seismic sounds with received levels greater than or 
equal to 160 dB re 1 [mu]Pa (rms) during the proposed low-energy 
seismic survey (including a 25% contingency) and greater than or equal 
to 120 dB re 1 [mu]Pa (rms) for icebreaking activities are in Table 6 
of this document. Of the cetaceans, 937 humpback, 2,151 Antarctic 
minke, 2,151 minke, 118 sei, 781 fin, 167 blue, and 252 sperm whales 
could be taken be Level B harassment during the proposed low-energy 
seismic survey, which would represent 9.88, 11.87, unknown, 0.15, 
16.72, 9.82, and 2.65% of the affected worldwide or regional 
populations, respectively. In addition, 343 Arnoux's beaked, 115 strap-
toothed beaked, and 300 southern bottlenose whales could be taken be 
Level B harassment during the proposed low-energy seismic survey, which 
would represent unknown, unknown, and 0.6% of the affected worldwide or 
regional populations, respectively. Of the delphinids, 532 killer 
whales, 1,018 long-finned pilot whales, and 483 hourglass dolphins 
could be taken be Level B harassment during the proposed low-energy 
seismic survey, which would represent 2.13, 0.51, and 0.34 of the 
affected worldwide or regional populations, respectively. Of the 
pinnipeds, 17,288 crabeater, 679 leopard, 425 Ross, 2,713 Weddell, and 
4 southern elephant seals could be taken by Level B harassment during 
the proposed low-energy seismic survey, which would represent 0.35, 
0.31, 2.13, 0.54, and <0.01 of the affected worldwide or regional 
population, respectively.
    No known current worldwide or regional population estimates are 
available for 3 species under NMFS's jurisdiction that could 
potentially be affected by Level B harassment over the course of the 
IHA. These species include the minke, Arnoux's beaked, and strap-
toothed beaked whales. Minke whales occur throughout the North Pacific 
Ocean and North Atlantic Ocean and the dwarf sub-species occurs in the 
Southern Hemisphere (Jefferson et al., 2008). Arnoux's beaked whales 
have a vast circumpolar distribution in the deep, cold waters of the 
Southern Hemisphere generally southerly from 34[deg] South. Strap-
toothed beaked whales are generally found in deep temperate waters 
(between 35 to 60[deg] South) of the Southern Hemisphere (Jefferson et 
al., 2008). Based on these distributions and preferences of these 
species, NMFS concludes that the requested take of these species likely 
represent small numbers relative to the affected species' overall 
population sizes.
    NMFS makes its small numbers determination based on the number of 
marine mammals that would be taken relative to the populations of the 
affected species or stocks. The requested take estimates all represent 
small numbers relative to the affected species or stock size (i.e., all 
are less than or equal to 16%), with the exception of the three species 
(i.e., minke, Arnoux's beaked, and strap-toothed beaked whales) for 
which a qualitative rationale was provided. 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 
preliminary finds that small numbers of marine mammals would be taken 
relative to the populations of the affected species or stocks. See 
Table 6 for the requested authorized take numbers of marine mammals.

Endangered Species Act

    Of the species of marine mammals that may occur in the proposed 
survey area, six are listed as endangered under the ESA: The southern 
right, humpback, sei, fin, blue, and sperm whales. Under section 7 of 
the ESA, NSF, on behalf of ASC and one other research institution, has 
initiated formal consultation with the NMFS, Office of Protected 
Resources, Endangered Species Act Interagency Cooperation Division, on 
this proposed low-energy seismic survey. NMFS's Office of Protected 
Resources, Permits and Conservation Division, has initiated formal 
consultation under section 7 of the ESA with NMFS's Office of Protected 
Resources, Endangered Species Act Interagency Cooperation Division, to 
obtain a Biological Opinion evaluating the effects of issuing the IHA 
on threatened and endangered marine mammals and, if appropriate, 
authorizing incidental take. NMFS would conclude formal section 7 
consultation prior to making a determination on whether or not to issue 
the IHA. If the IHA is issued, in addition to the mitigation and 
monitoring requirements included in the IHA, NSF and ASC would be 
required to comply with the Terms and Conditions of the Incidental Take 
Statement corresponding to NMFS's Biological Opinion issued to both NSF 
and ASC, and NMFS's Office of Protected Resources.

[[Page 68544]]

National Environmental Policy Act

    With NSF and ASC's complete application, NSF and ASC provided NMFS 
a ``Draft Initial Environmental Evaluation/Environmental Assessment to 
Perform Marine Geophysical Survey, Collect Bathymetric Measurements, 
and Conduct Sediment Coring by the RVIB Nathaniel B. Palmer in the Ross 
Sea,'' (IEE/EA), prepared by AECOM on behalf of NSF and ASC. The IEE/EA 
analyzes the direct, indirect, and cumulative environmental impacts of 
the proposed specified activities on marine mammals, including those 
listed as threatened or endangered under the ESA. NMFS, after 
independently reviewing and evaluating the document for sufficiency and 
compliance with Council on Environmental Quality (CEQ) NEPA regulations 
and NOAA Administrative Order 216-6 Sec.  5.09(d), will conduct a 
separate NEPA analysis and has prepared a ``Draft Environmental 
Assessment on the Issuance of an Incidental Harassment Authorization to 
the National Science Foundation and Antarctic Support Contract to Take 
Marine Mammals by Harassment Incidental to a Low-Energy Marine 
Geophysical Survey in the Ross Sea, January to April 2015,'' and decide 
whether to sign a Finding of No Significant Impact (FONSI), prior to 
making a determination on the issuance of the IHA.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to NSF and ASC for conducting the low-energy seismic 
survey in the Ross Sea, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated. This section 
contains a draft of the IHA itself. The wording contained in this 
section is proposed for inclusion in the IHA (if issued). The proposed 
IHA language is provided below:
    The NMFS hereby authorizes the National Science Foundation, 
Division of Polar Programs, 4201 Wilson Boulevard, Arlington, Virginia 
22230 and Antarctic Support Contract, 7400 South Tucson Way, 
Centennial, Colorado 80112, under section 101(a)(5)(D) of the Marine 
Mammal Protection Act (MMPA) (16 U.S.C. 1371(a)(5)(D)), to harass small 
numbers of marine mammals incidental to a low-energy marine geophysical 
(seismic) survey conducted by the RVIB Nathaniel B. Palmer (Palmer) in 
the Ross Sea, January to February 2015:
    1. Effective Dates
    This Authorization is valid from January 24, 2015 through April 9, 
2015.
    2. Specified Geographic Region
    This Authorization is valid only for NSF and ASC's activities 
associated with low-energy seismic survey, bathymetric profile, and 
core sampling operations as well as icebreaking activities conducted 
aboard the Palmer that shall occur in the following specified 
geographic area:
    (a) In selected regions of the Ross Sea (located north of the Ross 
Ice Shelf) in International Waters with a focus on the Whales Deep 
Basin trough (encompassing the region between 76 and 78[deg] South, and 
between 165 and 170[deg] West). Water depths in the survey area are 
expected to be 100 to 1,000 m. No airgun operations would occur in 
shallow (less than 100 m) water depths. The low-energy seismic survey 
would be conducted in International Waters (i.e., high seas), as 
specified in NSF and ASC's IHA application and the associated NSF and 
ASC Initial Environmental Evaluation/Environmental Assessment (IEE/EA).
    3. Species Authorized and Level of Takes
    (a) The incidental taking of marine mammals, by Level B harassment 
only, is limited to the following species in the waters of the Ross 
Sea:
    (i) Mysticetes--see Table 6 (above) for authorized species and take 
numbers.
    (ii) Odontocetes--see Table 6 (above) for authorized species and 
take numbers.
    (iii) Pinnipeds--see Table 6 (above) for authorized species and 
take numbers.
    (iv) If any marine mammal species are encountered during seismic 
activities that are not listed in Table 6 (above) for authorized taking 
and are likely to be exposed to sound pressure levels (SPLs) greater 
than or equal to 160 dB re 1 [mu]Pa (rms) for seismic airgun operations 
or greater than or equal to120 dB re 1 [mu]Pa (rms) for icebreaking 
activities, then the NSF and ASC must alter speed or course or shut-
down the airguns to prevent take.
    (b) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in Condition 3(a) above or the 
taking of any kind of any other species of marine mammal is prohibited 
and may result in the modification, suspension, or revocation of this 
Authorization.
    4. The methods authorized for taking by Level B harassment are 
limited to the following acoustic sources, without an amendment to this 
Authorization:
    (a) A two Generator Injector (GI) airgun array (each with a 
discharge volume of 105 cubic inches [in\3\]) with a total volume of 
210 in\3\ (or smaller); and
    (b) Icebreaking.
    5. Prohibited Take
    The taking of any marine mammal in a manner prohibited under this 
Authorization must be reported immediately to the Office of Protected 
Resources, National Marine Fisheries Service (NMFS), at 301-427-8401.
    6. Mitigation and Monitoring Requirements
    The NSF and ASC are required to implement the following mitigation 
and monitoring requirements when conducting the specified activities to 
achieve the least practicable impact on affected marine mammal species 
or stocks:

Protected Species Observers and Visual Monitoring

    (a) Utilize at least one NMFS-qualified, vessel-based Protected 
Species Observer (PSO) to visually watch for and monitor marine mammals 
near the seismic source vessel during daylight airgun operations (from 
nautical twilight-dawn to nautical twilight-dusk) and before and during 
ramp-ups of airguns day or night. Three PSOs shall be based onboard the 
vessel.
    (i) The Palmer's vessel crew shall also assist in detecting marine 
mammals, when practicable.
    (ii) PSOs shall have access to reticle binoculars (7 x 50 Fujinon) 
equipped with a built-in daylight compass and range reticles.
    (iii) PSO shifts shall last no longer than 4 hours at a time.
    (iv) PSO(s) shall also make observations during daylight periods 
when the seismic airguns are not operating, when feasible, for 
comparison of animal abundance and behavior.
    (v) PSO(s) shall conduct monitoring while the airgun array and 
streamer(s) are being deployed or recovered from the water.
    (b) PSO(s) shall record the following information when a marine 
mammal is sighted:
    (i) Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from seismic vessel, sighting cue, 
apparent reaction to the airguns or vessel (e.g., none, avoidance, 
approach, paralleling, etc., and including responses to ramp-up), and 
behavioral pace; and
    (ii) Time, location, heading, speed, activity of the vessel 
(including number of airguns operating and whether in state of ramp-up 
or shut-down), Beaufort sea state and wind force, visibility, and sun 
glare; and

[[Page 68545]]

    (iii) The data listed under Condition 6(b)(ii) shall also be 
recorded at the start and end of each observation watch and during a 
watch whenever there is a change in one or more of the variables.

Buffer and Exclusion Zones

    (c) Establish a 160 dB re 1 [mu]Pa (rms) buffer zone, as well as a 
180 dB re 1 [mu]Pa (rms) exclusion zone for cetaceans and a 190 dB re 1 
[mu]Pa (rms) exclusion zone for pinnipeds before the two GI airgun 
array (210 in\3\ total volume) is in operation. Establish a 120 dB re 1 
[mu]Pa (rms) buffer zone for cetaceans and pinnipeds before icebreaking 
activities begin. See Table 2 (above) for distances and buffer and 
exclusion zones.

Visual Monitoring at the Start of the Airgun Operations

    (d) Visually observe the entire extent of the exclusion zone (180 
dB re 1 [mu]Pa [rms] for cetaceans and 190 dB re 1 [mu]Pa [rms] for 
pinnipeds; see Table 2 [above] for distances) using NMFS-qualified 
PSOs, for at least 30 minutes prior to starting the airgun array.
    (i) If the PSO(s) sees a marine mammal within the exclusion zone, 
NSF and ASC must delay the seismic survey until the marine mammal(s) 
has left the area. If the PSO(s) sees a marine mammal that surfaces, 
then dives below the surface, the PSO(s) shall continue to observe the 
exclusion zone for 30 minutes, and if the PSO sees no marine mammals 
during that time, the PSO should assume that the animal has moved 
beyond the exclusion zone.
    (ii) If for any reason the entire radius cannot be seen for the 
entire 30 minutes (i.e., rough seas, fog, darkness), or if marine 
mammals are near, approaching, or in the exclusion zone, the airguns 
may not be ramped-up. If one airgun is already running at a source 
level of at least 180 dB re 1 [mu]Pa (rms), NSF and ASC may start the 
second airgun without observing the entire exclusion zone for 30 
minutes prior, provided no marine mammals are known to be near the 
exclusion zone (in accordance with Condition 6[e] below).

Ramp-Up Procedures

    (e) Implement a ``ramp-up'' procedure, which means starting with a 
single GI airgun and adding a second GI airgun after five minutes, when 
starting up at the beginning of seismic operations or anytime after the 
entire array has been shut-down for more than 15 minutes. During ramp-
up, the two PSOs shall monitor the exclusion zone, and if marine 
mammals are sighted, a shut-down shall be implemented as though the 
full array (both GI airguns) were operational. Therefore, initiation of 
ramp-up procedures from shut-down requires that the PSOs be able to 
view the full exclusion zone as described in Condition 6(d) (above).

Shut-Down Procedures

    (f) Shut-down the airgun(s) if a marine mammal is detected within, 
approaches, or enters the relevant exclusion zone (as defined in Table 
2, above). A shut-down means all operating airguns are shut-down (i.e., 
turned off).
    (g) Following a shut-down, the airgun activity shall not resume 
until the PSO(s) has visually observed the marine mammal exiting the 
exclusion zone and determined it is not likely to return, or has not 
seen the marine mammal within the exclusion zone for 15 minutes, for 
species with shorter dive durations (small odontocetes and pinnipeds), 
or 30 minutes for species with longer dive durations (mysticetes and 
large odontocetes, including sperm, killer, and beaked whales).
    (h) Following a shut-down and subsequent animal departure, airgun 
operations may resume, following the ramp-up procedures described in 
Condition 6(e).

Speed or Course Alteration

    (i) Alter speed or course during seismic operations if a marine 
mammal, based on its position and relative motion, appears likely to 
enter the relevant exclusion zone. If speed or course alteration is not 
safe or practicable, or if after alteration the marine mammal still 
appears likely to enter the exclusion zone, further mitigation 
measures, such as a shut-down, shall be taken.

Survey Operations During Low-Light Hours

    (j) Marine seismic surveying may continue into low-light hours if 
such segment(s) of the survey is initiated when the entire relevant 
exclusion zones are visible and can be effectively monitored.
    (k) No initiation of airgun array operations is permitted from a 
shut-down position during low-light hours (such as in dense fog or 
heavy rain) when the entire relevant exclusion zone cannot be 
effectively monitored by the PSO(s) on duty.
    (l) To the maximum extent practicable, schedule seismic operations 
(i.e., shooting airguns) during daylight hours.
    7. Reporting Requirements
    The NSF and ASC are required to:
    (a) Submit a draft report on all activities and monitoring results 
to the Office of Protected Resources, NMFS, within 90 days of the 
completion of the Palmer's Ross Sea cruise. This report must contain 
and summarize the following information:
    (i) Dates, times, locations, heading, speed, weather, sea 
conditions (including Beaufort sea state and wind force), and 
associated activities during all seismic operations and marine mammal 
sightings;
    (ii) Species, number, location, distance from the vessel, and 
behavior of any marine mammals, as well as associated seismic activity 
(e.g., number of shut-downs), observed throughout all monitoring 
activities.
    (iii) An estimate of the number (by species) of marine mammals 
that: (A) Are known to have been exposed to the seismic activity (based 
on visual observation) at received levels greater than or equal to 120 
dB re 1 [mu]Pa (rms) (for icebreaking activities), greater than or 
equal to 160 dB re 1 [mu]Pa (rms) (for seismic airgun operations), and/
or 180 dB re 1 [mu]Pa (rms) for cetaceans and 190 dB re 1 [mu]Pa (rms) 
for pinnipeds, with a discussion of any specific behaviors those 
individuals exhibited; and (B) may have been exposed (based on modeled 
values for the two GI airgun array) to the seismic activity at received 
levels greater than or equal to 120 dB re 1 [mu]Pa (rms) (for 
icebreaking activities), greater than or equal to 160 dB re 1 [mu]Pa 
(rms) (for seismic airgun operations), and/or 180 dB re 1 [mu]Pa (rms) 
for cetaceans and 190 dB re 1 [mu]Pa (rms) for pinnipeds, with a 
discussion of the nature of the probable consequences of that exposure 
on the individuals that have been exposed.
    (iv) A description of the implementation and effectiveness of the: 
(A) Terms and Conditions of the Biological Opinion's Incidental Take 
Statement (ITS) (attached); and (B) mitigation measures of the IHA. For 
the Biological Opinion, the report shall confirm the implementation of 
each Term and Condition, as well as any conservation recommendations, 
and describe their effectiveness, for minimizing the adverse effects of 
the action on Endangered Species Act-listed marine mammals.
    (b) Submit a final report to the Chief, Permits and Conservation 
Division, Office of Protected Resources, NMFS, within 30 days after 
receiving comments from NMFS on the draft report. If NMFS decides that 
the draft report needs no comments, the draft report shall be 
considered to be the final report.
    8. Reporting Prohibited Take
    (a)(i) In the unanticipated event that the specified activity 
clearly causes the take of a marine mammal in a manner prohibited by 
this Authorization, such as an injury (Level A harassment),

[[Page 68546]]

serious injury or mortality (e.g., through ship-strike, gear 
interaction, and/or entanglement), NSF and ASC shall immediately cease 
the specified activities and immediately report the incident to the 
Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, at 301-427-8401 and/or by email to 
Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov. The report must 
include the following information:
    (ii) Time, date, and location (latitude/longitude) of the incident; 
the name and type of vessel involved; the vessel's speed during and 
leading up to the incident; description of the incident; status of all 
sound source use in the 24 hours preceding the incident; water depth; 
environmental conditions (e.g., wind speed and direction, Beaufort sea 
state, cloud cover, and visibility); description of marine mammal 
observations in the 24 hours preceding the incident; species 
identification or description of the animal(s) involved; the fate of 
the animal(s); and 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 NSF and ASC 
to determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. NSF and ASC may not resume 
their activities until notified by NMFS via letter, email, or 
telephone.

Reporting an Injured or Dead Marine Mammal With an Unknown Cause of 
Death

    (b) In the event that NSF and ASC discover 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), NSF and ASC shall immediately 
report the incident to the Chief of the Permits and Conservation 
Division, Office of Protected Resources, NMFS, at 301-427-8401, and/or 
by email to Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov. The 
report must include the same information identified in Condition 
7(c)(i) above. Activities may continue while NMFS reviews the 
circumstances of the incident. NMFS shall work with NSF and ASC to 
determine whether modifications in the activities are appropriate.

Reporting an Injured or Dead Marine Mammal Not Related to the 
Activities

    (c) In the event that NSF and ASC discover 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 
Condition 2 of this Authorization (e.g., previously wounded animal, 
carcass with moderate to advanced decomposition, or scavenger damage), 
NSF and ASC shall report the incident to the Chief of the Permits and 
Conservation Division, Office of Protected Resources, NMFS, at 301-427-
8401, and/or by email to Jolie.Harrison@noaa.gov and 
Howard.Goldstein@noaa.gov, within 24 hours of the discovery. NSF and 
ASC shall provide photographs or video footage (if available) or other 
documentation of the stranded animal sighting to NMFS. Activities may 
continue while NMFS reviews the circumstances of the incident.
    9. Endangered Species Act Biological Opinion and Incidental Take 
Statement
    (a) NSF and ASC are required to comply with the Terms and 
Conditions of the ITS corresponding to NMFS's Biological Opinion issued 
to both NSF and ASC, and NMFS's Office of Protected Resources.
    (b) A copy of this Authorization and the ITS must be in the 
possession of all contractors and PSO(s) operating under the authority 
of this Incidental Harassment Authorization.

Request for Public Comments

    NMFS requests comment on our analysis, the draft authorization, and 
any other aspect of the notice of the proposed IHA for NSF and ASC's 
low-energy seismic survey. Please include with your comments any 
supporting data or literature citations to help inform our final 
decision on NSF and ASC's request for an MMPA authorization. Concurrent 
with the publication of this notice in the Federal Register, NMFS is 
forwarding copies of this application to the Marine Mammal Commission 
and its Committee of Scientific Advisors.

    Dated: November 7, 2014.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2014-26915 Filed 11-14-14; 8:45 am]
BILLING CODE 3510-22-P