[Federal Register Volume 79, Number 150 (Tuesday, August 5, 2014)]
[Notices]
[Pages 45592-45625]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-18396]



[[Page 45591]]

Vol. 79

Tuesday,

No. 150

August 5, 2014

Part II





 Securities and Exchange Commission





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Takes of Marine Mammals Incidental to Specified Activities; Low-Energy 
Marine Geophysical Survey in the Scotia Sea and South Atlantic Ocean, 
September to October 2014; Notice

  Federal Register / Vol. 79 , No. 150 / Tuesday, August 5, 2014 / 
Notices  

[[Page 45592]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD256


Takes of Marine Mammals Incidental to Specified Activities; Low-
Energy Marine Geophysical Survey in the Scotia Sea and South Atlantic 
Ocean, September to October 2014

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 two research institutions, University of 
Texas at Austin and University of Memphis, for an Incidental Harassment 
Authorization (IHA) to take marine mammals, by harassment, incidental 
to conducting a low-energy marine geophysical (seismic) survey in the 
Scotia Sea and South Atlantic Ocean, September to October 2014. 
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, 26 species of marine mammals during 
the specified activity.

DATES: Comments and information must be received no later than 
September 4, 2014.

ADDRESSES: Comments on the application should be addressed to Jolie 
Harrison, Incidental Take Program, 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 [email protected]. 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: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications 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 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: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. 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 Conduct a Study of the Role of 
the Central Scotia Sea and North Scotia Ridge in the Onset and 
Development of the Antarctic Circumpolar Current'' (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 will independently evaluate the 
IEE/EA and determine whether or not to adopt it. NMFS may prepare a 
separate NEPA analysis and incorporate relevant portions of the NSF and 
ASC's draft IEE/EA by reference. Information in the NSF and ASC's IHA 
application, EA and this notice 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 April 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 the Exclusive Economic Zone (EEZ) 
of the South Georgia and South Sandwich Islands and International 
Waters (i.e., high seas) in the Scotia Sea and southern Atlantic Ocean 
during September to October 2014.
    The research would be conducted by two research institutions: 
University of Texas at Austin and University of Memphis. NSF and ASC 
plan to use one source vessel, the R/VIB Nathaniel B. Palmer (Palmer), 
and a seismic airgun array and hydrophone streamer to collect seismic 
data in the Scotia Sea and southern Atlantic Ocean. The vessel

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would be operated by ASC, which operates the United 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 Scotia Sea, including evaluation of 
lithosphere adjacent to and beneath the Scotia Sea and southern 
Atlantic Ocean in two areas, the South Georgia micro-continent and the 
seafloor of the eastern portion of the central Scotia Sea (see Figures 
1 and 2 of the IHA application). In addition to the proposed operations 
of the seismic airgun array and hydrophone streamer, 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 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 26 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 30 
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 proposes 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 ``Role of 
Central Scotia Sea Floor and North Scotia Ridge in the Onset and 
Development of the Antarctic Circumpolar Current.'' In addition to the 
airguns, NSF and ASC intend to conduct a bathymetric survey, dredge 
sampling, and geodetic measurements from the Palmer during the proposed 
low-energy seismic survey.

Dates and Duration

    The Palmer is expected to depart from Punta Arenas, Chile on 
approximately September 20, 2014 and arrive at Punta Arenas, Chile on 
approximately October 20, 2014. Research operations would be conducted 
over a span of 30 days, including to and from port. 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 seismic 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 Scotia Sea (located northeast of the Antarctic 
Peninsula) and the southern Atlantic Ocean and focus on two areas: (1) 
Between the central rise of the Scotia Sea and the East Scotia Sea, and 
(2) the far southern Atlantic Ocean immediately northeast of South 
Georgia towards the northeastern Georgia Rise (both encompassing the 
region between 53 to 58[deg] South, and between 33 to 40[deg] West) 
(see Figure 2 of the IHA application). The majority of the proposed 
seismic survey would be within the EEZ of the Government of the South 
Georgia and South Sandwich Islands (United Kingdom) and a limited 
portion of the seismic survey would be conducted in International 
Waters. Figure 3 of the IHA application illustrates the general 
bathymetry of the proposed study area and the border of the existing 
South Georgia Maritime Zone. Water depths in the survey area exceed 
1,000 m. There is limited information on the depths in the study area 
and therefore more detailed information on bathymetry is not available. 
The proposed seismic survey would be within an area of approximately 
3,953 km\2\ (1,152.5 nmi\2\). This estimate is based on the maximum 
number of kilometers for the seismic survey (2,950 km) multiplied by 
the predicted rms radii (m) based on modeling and empirical 
measurements (assuming 100% use of the two 105 in\3\ GI airguns in 
greater than 1,000 m water depths), which was calculated to be 675 m 
(2,214.6 ft).

Detailed Description of the Proposed Specified Activity

    NSF and ASC propose to conduct a low-energy seismic survey in the 
Scotia Sea and the southern Atlantic Ocean from September to October 
2014. In addition to the low-energy seismic survey, scientific 
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; collecting global positioning 
system (GPS) information through the temporary installation of three 
continuous Global Navigation Satellite Systems (cGNSS) on the South 
Georgia micro-continent; and collecting dredge sampling around the 
edges of seamounts or ocean floor with significant magnetic anomalies 
to determine the nature and age of bathymetric highs near the eastern 
edge of the central Scotia Sea. Water depths in the survey area are 
greater than 1,000 meters (m) (3,280.1 feet [ft]). The seismic survey 
is scheduled to occur for a total of approximately 325 hours over the 
course of the entire cruise, which would be for approximately 30 
operational days in September to October 2014. The proposed seismic 
survey would be conducted during the day and night, and for up to 40 
hours of continuous operations at a time. The operation hours and 
survey length would include equipment testing, ramp-up, line changes, 
and repeat coverage. The long transit time between port and the study 
site constrains how long the ship can be in the study area and 
effectively limits the maximum amount of time the airguns can operate. 
Some minor deviation from these dates would be possible, depending on 
logistics and weather.
    The proposed survey of the Scotia Sea and southern Atlantic Ocean 
would involve conducting single channel seismic reflection profiling 
across the northern central Scotia Sea along two lines that cross the 
seismically active and apparently compressive boundary between the 
South Georgia micro-continent and the Northeast Georgia Rise. The 
targeted seismic survey would occur in the unexplored zones of elevated 
crust in the eastern central Scotia Sea and is designed to address 
several critical questions with respect to the tectonic nature of the 
northern and southern boundaries of the South Georgia micro-continent.
    Opening of deep Southern Ocean gateways between Antarctica and 
South America and between Antarctica and Australia permitted complete 
circum-Antarctic circulation. This Antarctic Circumpolar Current is not 
well understood. The Antarctic Circumpolar Current may have been 
critical in the transition from a warm Earth in the early Cenozoic to 
the subsequent much

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cooler conditions that persist to the present day. Opening of Drake 
Passage and the west Scotia Sea likely broke the final barrier formed 
by the Andes of Tierra del Fuego and the ``Antarctandes'' of the 
Antarctic Peninsula. Once this deep gateway, usually referred to as the 
Drake Passage gateway, was created, the strong and persistent mid-
latitude winds could generate one of the largest deep currents on 
Earth, at approximately 135 Sverdrup (a Sverdrup [Sv] is a measure of 
average flow rate in million cubic meters of water per second). This 
event is widely believed to be closely associated in time with a major, 
abrupt drop in global temperatures and the rapid expansion of the 
Antarctic ice sheets at 33 to 34 Million Annus (Ma, i.e., million years 
from the present/before the current date), the Eocene-Oligocene 
boundary.
    The events leading to the complete opening of the Drake Passage 
gateway are very poorly known. The uncertainty is due to the complex 
tectonic history of the Scotia Sea and its enclosing Scotia Ridge, the 
eastward-closing, locally emergent submarine ridge that joins the 
southernmost Andes to the Antarctic Peninsula and deflects the 
Antarctic Circumpolar Current through gaps in its northern limb. The 
critical keys to this problem are the enigmatic floor of the central 
Scotia Sea between the high relief South Georgia (approximately 3,000 m 
[9,842.5 ft]) and the lower South Orkney islands (approximately 1,200 m 
[3,937 ft]), emergent parts of micro-continental blocks on the North 
and South Scotia ridges respectively, and the North Scotia Ridge 
itself.
    In 2008, an International Polar Year research program was conducted 
using the RVIB Nathaniel B. Palmer (Palmer) (Cruise NBP 0805) that was 
designed to elucidate the structure and history of this area to help 
provide the constraints necessary for understanding of the initiation 
of the critical Drake Passage--Scotia Sea gateway. Underway data and 
dredged samples produced unexpected results that led to a structurally 
different view of the central Scotia Sea and highlighted factors 
bearing on initiation of the Antarctic Circumpolar Current that had not 
been previously considered.
    The results of this study of the central Scotia Sea are fragmentary 
due to the limited time available during Cruise NBP 0805. Therefore, 
the extent, geometry, and physiography of a submerged volcanic arc that 
may have delayed formation of a complete Antarctic Circumpolar Current 
until after the initiation of Antarctic glaciation are poorly defined, 
with direct dating limited to a few sites. To remedy these 
deficiencies, thereby further elucidating the role of the central 
Scotia Sea in the onset and development of the Antarctic Circumpolar 
Current, the proposed targeted surveying and dredging would determine 
likely arc constructs in the eastern central Scotia Sea. These would be 
combined with a survey of the margins of the South Georgia micro-
continent and installation of three continuous GPS stations on South 
Georgia that would test the hypothesis regarding the evolution of the 
North Scotia Ridge, also an impediment to the present Antarctic 
Circumpolar Current. The Principal Investigators are Dr. Ian Dalziel 
and Dr. Lawrence Lawver of the University of Texas at Austin, and Dr. 
Robert Smalley of the University of Memphis.
    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 greater than 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 and sea conditions would be closely monitored, 
including for conditions that could limit visibility. Pack ice is not 
anticipated to be encountered during the proposed cruise; therefore, no 
icebreaking activities are expected. 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 2,950 kilometers (km) (1,592.9 nautical 
miles [nmi]) of transect lines (including turns) in the survey area in 
the Scotia Sea and southern Atlantic Ocean (see Figures 1, 2, and 3 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 seismic 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.

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    Table 1--Proposed Low-Energy Seismic Survey Activities in the Scotia Sea and the Southern Atlantic Ocean
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                                     Cumulative
       Survey length  (km)         duration (hr)    Airgun array total  Time between airgun  Streamer length (m)
                                        \1\               volume          shots (distance)
----------------------------------------------------------------------------------------------------------------
2,950 (1,592.9 nmi).............            ~325   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 40 continuous hours at a time.

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: http://www.nsf.gov/geo/plr/support/nathpalm.jsp and http://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 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 is 
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. At 
vessel speeds of approximately 9.3 km/hr, the shot intervals correspond 
to spacing of approximately 12.5 m (41 ft) during the study. 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 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. 
The airguns would fire the compressed air volume in unison in a 
harmonic mode. 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 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 at 3 m tow depth that 
are close approximations. For the two 105 in\3\ airgun array, the 
source output (downward) is 234.4 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 160 Hz for a pair of GI airguns 
towed at 3 m depth and 35 to 230 Hz for a pair of GI airguns towed at 2 
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 40 hours at a time. The 
cumulative duration of the airgun operations would not exceed 325 hrs. 
The relatively short, 24-channel hydrophone streamer would provide 
operational flexibility to allow the seismic survey to proceed along 
the designated cruise track. 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

[[Page 45596]]

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 
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 228.2 dB re 1 [micro]Pam peak or 233.5 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 Attachment 
A of the IEE/EA). 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 [mu]Pa (rms) are predicted to be received in deep water 
are shown in Table 2 (see Table 1 of Attachment A of the IEE/EA).
    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; 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 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). Measurements 
were not made for a two GI airgun array in 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 deep 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 [mu]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 [mu]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 deep water (greater 
than 1,000 m [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
                      Scotia Sea and the Southern Atlantic Ocean, September to October 2014
----------------------------------------------------------------------------------------------------------------
                                                                         Predicted RMS radii distances (m) for 2
                                              Tow depth    Water depth               GI airgun array
          Source and total volume                (m)           (m)     -----------------------------------------
                                                                           160 dB        180 dB        190 dB
----------------------------------------------------------------------------------------------------------------
Two GI Airguns (105 in\3\)................       3 to 4          Deep           670           100          20 *
                                                             (>1,000)   (2,198.2 ft)   (328.1 ft)     (65.6 ft)
----------------------------------------------------------------------------------------------------------------
* 100 would be used for pinnipeds as well as cetaceans.


[[Page 45597]]

    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 
acquisition should allow marine mammals to avoid the vessel.

Bathymetric Survey

    Along with the low-energy airgun operations, other additional 
geophysical measurements would be made using swath bathymetry, 
backscatter sonar imagery, high-resolution sub-bottom profiling 
(``CHIRP''), imaging, and magnetometer instruments. In addition, 
several other transducer-based instruments onboard the vessel would be 
operated continuously during the cruise for operational and 
navigational purposes. During 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.
    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.
    Passive Instruments--During the seismic survey in the Scotia Sea 
and southern Atlantic Ocean, a precession magnetometer and Air-Sea 
gravity meter would be deployed. In addition, numerous (approximately 
60) 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.

Dredge Sampling

    The primary sampling goals involve the acquisition of in situ rock 
samples from deep marine rises (escarpments) at 3,000 to 4,000 m 
(9,842.5 to 13,123.4 ft) depths to determine the composition and age of 
the seafloor. Underway multi-beam and seismic data would be used to 
locate submarine outcrops. Dredging would be conducted upslope on 
escarpments. No dredging would be undertaken across the top of any 
seamounts, and final selection of dredge sites would include review to 
ensure that the tops of seamounts and corals in the area are avoided.
    It is anticipated that researchers would survey and dredge two deep 
marine rises and one topographic high (see areas A and B in Figure 2 of 
the IHA application). There will be only six deployments of the dredge. 
The dredge buckets would be less than 1 m (3.28 ft) across and each 
sample area to be dredged would be no longer than approximately 1,000 
m. Approximately 1,000 m\2\ (10,763.9 ft\2\) of seafloor would be 
disturbed by each deployment of the dredge at two different sites 
(resulting in a total of approximately 6,000 m\2\ [64,583.46 ft\2\] of 
affected seafloor for the proposed project). Six samples would be 
taken, with each dredge effort being 1,000 m\2\ in length. Two samples 
would be collected from each of two locations (seamount sides) at Box A 
and two samples would be collected from one location at Box B (see 
Figure 2 of the IHA application).

               Table 3--Proposed Dredging Activities in the Scotia Sea and Southern Atlantic Ocean
----------------------------------------------------------------------------------------------------------------
                                                                Area (see Figure 2 of
                       Sampling device                          the IHA application)      Number of deployments
----------------------------------------------------------------------------------------------------------------
Scripps Institution of Oceanography (SIO)-style Deep Sea                      A and B                         3
 Rock Dredge................................................
----------------------------------------------------------------------------------------------------------------

    The Government of South Georgia and South Sandwich Islands has 
established a large sustainable use Marine Protected Area covering over 
1 million km\2\ (291,553.35 nmi\2\) of the South Georgia and South 
Sandwich Islands Maritime Zone. Activities within the Marine Protected 
Area are subject to the requirements of the current Management Plan 
(see Attachment C of the IHA application). The area was designated as a 
Marine Protected Area to ensure the protection and conservation of the 
resources and biodiversity and support important ecosystem roles, such 
as feeding areas for marine mammals, and penguins and other seabirds. 
Research activities, including trawling and sampling the seafloor, 
require application for a permit issued by the Government of South 
Georgia and South Sandwich Islands.
    The Commission for the Conservation of Antarctic Marine Living 
Resources (CCAMLR) has adopted Conservation Measures 22-06, 22-07, and 
22-09 to protect vulnerable marine ecosystems, which include seamounts, 
hydrothermal vents, cold water corals, and sponge fields. These 
measures apply to the entire proposed study area. Additionally, the 
area surrounding South Georgia Island was designated by CCAMLR as an 
Integrated Study Area to assist with the collection and management of 
information relating to the CCAMLR Ecosystem Monitoring Program. The 
Conservation Measure 22-07 includes mitigation and reporting 
requirements if vulnerable marine ecosystems are encountered. The 
science team would follow these requirements (see Attachment C of the 
IHA application) if vulnerable marine ecosystems are encountered while

[[Page 45598]]

sampling the sea bottom; however, the specific intent of the proposed 
dredging activities is to avoid obtaining material from the tops of 
seamounts.

Geodetic Measurements

    Researchers would install three continuous Global Navigation 
Satellite System (cGNSS) stations on the South Georgia micro-continent 
(see Figure 3 of the IHA application). The cGNSS systems would collect 
GPS and meteorological data with daily data recovery using IRIDIUM-
based communications. These stations would complement the cGNSS station 
installed at King Edward Point in Cumberland Bay on the northeastern 
side of the island (see the ``red star'' in Figure 3 of the IHA 
application). One station would be installed near Cooper Bay on the 
southeastern extremity of the island, the second station would be 
installed on a reef or islet between Cooper Bay and Annenkov Island, 
and the third station would be installed on Bird Island. The stations 
would be removed after three years of operation.

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

    Various national Antarctic research programs (e.g., British 
Antarctic Survey, Australian Antarctic Division, and NMFS National 
Marine Mammal Laboratory), academic institutions (e.g., Duke 
University, University of St. Andrews, and Woods Hole Oceanographic 
Institution), and other organizations (e.g., South Georgia Museum, 
Fundacion Cethus, Whale and Dolphin Conservation, and New England 
Aquarium) have conducted scientific cruises and/or examined data on 
marine mammal sightings along the coast of Antarctica, south Atlantic 
Ocean, Scotia Sea, and around South Georgia and South Sandwich islands, 
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 
Atlantic Ocean in proximity to the proposed action area in the Scotia 
Sea include 32 species of cetaceans and 7 species of pinnipeds.
    The waters of the Scotia Sea and southern Atlantic Ocean, 
especially those near South Georgia Island, are characterized by high 
biomass and productivity of phytoplankton, zooplankton, and vertebrate 
predators, and may be a feeding ground for many of these marine mammals 
(Richardson, 2012). In general, many of the species present in the sub-
Antarctic study area may be present or migrating through the Scotia Sea 
during the proposed low-energy seismic survey. Many of the species that 
may be potentially present in the study area 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 six species of pinnipeds that are found in the southern 
Atlantic Ocean and Southern Ocean and may be present in the proposed 
study area include the crabeater (Lebodon carcinophagus), leopard 
(Hydrurga leptonyx), Weddell (Leptonychotes weddellii), southern 
elephant (Mirounga leonina), Antarctic fur (Arctocephalus gazella), and 
Subantarctic fur (Arctocephalus tropicalis) seal. Many of these 
pinniped species breed on either the pack ice or subantarctic islands. 
The southern elephant seal and Antarctic fur seal have haul-outs and 
rookeries that are located on subantarctic islands and prefer beaches. 
The Ross seal (Ommatophoca rossii) is generally found in dense 
consolidated pack ice and on ice floes, but may migrate into open water 
to forage. This species' 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 26 species known to occur in the Scotia Sea and 
the southern Atlantic Ocean, there are 14 cetacean species with ranges 
that are known to potentially occur in the waters of the study area: 
Pygmy right (Caperea marginata), Bryde's (Balaenoptera brydei), dwarf 
minke (Balaenoptera acutorostrata spp.), pygmy blue (Balaenoptera 
musculus brevicauda), pygmy sperm (Kogia breviceps), dwarf sperm (Kogia 
sima), Andrew's beaked (Mesoplodon bowdoini), Blainville's beaked 
(Mesoplodon densirostris), Hector's beaked (Mesoplodon hectori), and 
spade-toothed beaked (Mesoplodon traversii) whale, and Commerson's 
(Cephalorhynchus commersonii), Dusky (Lagenorhynchus obscurus), 
bottlenose (Tursiops truncatus), and Risso's (Grampus griseus) dolphin. 
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 status, and conservation status of the species of marine 
mammals that may occur in the proposed study area during September to 
October 2014.

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 Scotia Sea and Southern Atlantic Ocean
                                   [See text and Tables 6 and 7 in NSF and ASC's IHA application for further details]
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Species                      Habitat             Occurrence               Range          Population estimate     ESA \1\        MMPA \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
    Southern right whale            Coastal, pelagic....  Common..............  Circumpolar 20 to     8,000 \3\ to 15,000   EN             D
     (Eubalaena australis).                                                      55[deg] South.        \4\.
    Pygmy right whale (Caperea      Coastal, pelagic....  Rare................  30 to 55[deg] South.  NA..................  NL             NC
     marginata).
    Humpback whale (Megaptera       Pelagic, nearshore    Common..............  Cosmopolitan........  35,000 to 40,000      EN             D
     novaeangliae).                  waters, and banks.                                                \3\--Worldwide
                                                                                                       9,484 \5\--Scotia
                                                                                                       Sea and Antarctica
                                                                                                       Peninsula.

[[Page 45599]]

 
    Minke whale (Balaenoptera       Pelagic and coastal.  Common..............  Circumpolar--Souther  NA..................  NL             NC
     acutorostrata including dwarf                                               n Hemisphere to
     sub-species).                                                               65[deg] South.
    Antarctic minke whale           Pelagic, ice floes..  Common..............  7[deg] South to ice   Several 100,000 \3\-- NL             NC
     (Balaenoptera bonaerensis).                                                 edge (usually 20 to   Worldwide 18,125
                                                                                 65[deg] South).       \5\--Scotia Sea and
                                                                                                       Antarctica
                                                                                                       Peninsula.
    Bryde's whale (Balaenoptera     Pelagic and coastal.  Rare................  Circumglobal 40[deg]  NA..................  NL             NC
     brydei).                                                                    North to 40[deg]
                                                                                 South.
    Sei whale (Balaenoptera         Primarily offshore,   Uncommon............  Migratory, Feeding    80,000 \3\--          EN             D
     borealis).                      pelagic.                                    Concentration 40 to   Worldwide.
                                                                                 50[deg] South.
    Fin whale (Balaenoptera         Continental slope,    Common..............  Cosmopolitan,         140,000 \3\--         EN             D
     physalus).                      pelagic.                                    Migratory.            Worldwide 4,672
                                                                                                       \5\--Scotia Sea and
                                                                                                       Antarctica
                                                                                                       Peninsula.
    Blue whale (Balaenoptera        Pelagic, shelf,       Uncommon............  Migratory Pygmy blue  8,000 to 9,000 \3\--  EN             D
     musculus; including pygmy       coastal.                                    whale--North of       Worldwide 1,700
     blue whale [Balaenoptera                                                    Antarctic             \6\--Southern Ocean.
     musculus brevicauda]).                                                      Convergence 55[deg]
                                                                                 South.
Odontocetes:
    Sperm whale (Physeter           Pelagic, deep sea...  Common..............  Cosmopolitan,         360,000 \3\--         EN             D
     macrocephalus).                                                             Migratory.            Worldwide 9,500
                                                                                                       \3\--Antarctic.
    Pygmy sperm whale (Kogia        Pelagic, slope......  Rare................  Widely distributed    NA..................  NL             NC
     breviceps).                                                                 in tropical and
                                                                                 temperate zones.
    Dwarf sperm whale (Kogia sima)  Pelagic, slope......  Rare................  Widely distributed    NA..................  NL             NC
                                                                                 in tropical and
                                                                                 temperate zones.
    Arnoux's beaked whale           Pelagic.............  Common..............  Circumpolar in        NA..................  NL             NC
     (Berardius arnuxii).                                                        Southern
                                                                                 Hemisphere, 24 to
                                                                                 78[deg] South.
    Cuvier's beaked whale (Ziphius  Pelagic.............  Uncommon............  Cosmopolitan........  NA..................  NL             NC
     cavirostris).
    Shepherd's beaked whale         Pelagic.............  Common..............  Circumpolar--south    NA..................  NL             NC
     (Tasmacetus shepherdi).                                                     of 30[deg] South.
    Southern bottlenose whale       Pelagic.............  Common..............  Circumpolar--30[deg]  500,000 \3\--South    NL             NC
     (Hyperoodon planifrons).                                                    South to ice edge.    of Antarctic
                                                                                                       Convergence.
    Andrew's beaked whale           Pelagic.............  Rare................  32 to 55[deg] South.  NA..................  NL             NC
     (Mesoplodon bowdoini).
    Blainville's beaked whale       Pelagic.............  Rare................  Temperate and         NA..................  NL             NC
     (Mesoplodon densirostris).                                                  tropical waters
                                                                                 worldwide.
    Gray's beaked whale             Pelagic.............  Common..............  30[deg] South to      NA..................  NL             NC
     (Mesoplodon grayi).                                                         Antarctic waters.
    Hector's beaked whale           Pelagic.............  Rare................  Circumpolar--cool     NA..................  NL             NC
     (Mesoplodon hectori).                                                       temperate waters of
                                                                                 Southern Hemisphere.
    Spade-toothed beaked whale      Pelagic.............  Rare................  Circumantarctic.....  NA..................  NL             NC
     (Mesoplodon traversii).
    Strap-toothed beaked whale      Pelagic.............  Common..............  30[deg] South to      NA..................  NL             NC
     (Mesoplodon layardii).                                                      Antarctic
                                                                                 Convergence.
    Killer whale (Orcinus orca)...  Pelagic, shelf,       Common..............  Cosmopolitan........  80,000 \3\--South of  NL             NC
                                     coastal, pack ice.                                                Antarctic
                                                                                                       Convergence 25,000
                                                                                                       \7\--Southern Ocean.
    Long-finned pilot whale         Pelagic, shelf,       Common..............  Circumpolar--19 to    200,000 \3\ \8\--     NL             NC
     (Globicephala melas).           coastal.                                    68[deg] South in      South of Antarctic
                                                                                 Southern Hemisphere.  Convergence.
    Risso's dolphin (Grampus        Shelf, slope,         Rare................  60[deg] North to      NA..................  NL             NC
     griseus).                       seamounts.                                  60[deg] South.
    Bottlenose dolphin (Tursiops    Offshore, inshore,    Rare................  45[deg] North to      >625,500 \3\--        NL             NC
     truncatus).                     coastal, estuaries.                         45[deg] South.        Worldwide.
    Southern right whale dolphin    Pelagic.............  Uncommon............  12 to 65[deg] South.  NA..................  NL             NC
     (Lissodelphis peronii).
    Peale's dolphin                 Coastal, continental  Uncommon............  33 to 60[deg] South.  NA..................  NL             NC
     (Lagenorhynchus australis).     shelf, islands.                                                  200--southern Chile
                                                                                                       \3\.
    Commerson's dolphin             Coastal, continental  Rare................  South America         3,200--Strait of      NL             NC
     (Cephalorhynchus commersonii).  shelf, islands.                             Falkland Islands      Magellan \3\.
                                                                                 Kerguelen Islands.
    Dusky dolphin (Lagenorhynchus   Coastal, continental  Rare................  Widespread in         NA..................  NL             NC
     obscurus).                      shelf and slope.                            Southern Hemisphere.
    Hourglass dolphin               Pelagic, ice edge...  Common..............  33[deg] South to      144,000 \3\--South    NL             NC
     (Lagenorhynchus cruciger).                                                  pack ice.             of Antarctic
                                                                                                       Convergence.
    Spectacled porpoise (Phocoena   Coastal, pelagic....  Uncommon............  Circumpolar--Souther  NA..................  NL             NC
     dioptrica).                                                                 n Hemisphere.

[[Page 45600]]

 
Pinnipeds:
    Crabeater seal (Lobodon         Coastal, pack ice...  Common..............  Circumpolar--Antarct  5,000,000 to          NL             NC
     carcinophaga).                                                              ic.                   15,000,000 \3\ \9\.
    Leopard seal (Hydrurga          Pack ice, sub-        Common..............  Sub-Antarctic         220,000 to 440,000    NL             NC
     leptonyx).                      Antarctic islands.                          islands to pack ice.  \3\ \10\.
    Ross seal (Ommatophoca rossii)  Pack ice, smooth ice  Rare................  Circumpolar--Antarct  130,000 \3\, 20,000   NL             NC
                                     floes, pelagic.                             ic.                   to 220,000 \14\.
    Weddell seal (Leptonychotes     Fast ice, pack ice,   Uncommon............  Circumpolar--Souther  500,000 to 1,000,000  NL             NC
     weddellii).                     sub-Antarctic                               n Hemisphere.         \3\ \11\.
                                     islands.
    Southern elephant seal          Coastal, pelagic,     Common..............  Circumpolar--Antarct  640,000 \12\ to       NL             NC
     (Mirounga leonina).             sub-Antarctic                               ic Convergence to     650,000 \3\,
                                     waters.                                     pack ice.             470,000--South
                                                                                                       Georgia Island \14\.
    Antarctic fur seal              Shelf, rocky          Common..............  Sub-Antarctic         1,600,000 \13\ to     NL             NC
     (Arctocephalus gazella).        habitats.                                   islands to pack ice   3,000,000 \3\.
                                                                                 edge.
    Subantarctic fur seal           Shelf, rocky          Uncommon............  Subtropical front to  Greater than 310,000  NL             NC
     (Arctocephalus tropicalis).     habitats.                                   sub-Antarctic         \3\.
                                                                                 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 project area. The 
IHA application also presents how NSF and ASC calculated the estimated 
densities for the marine mammals in the proposed survey 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) 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):
     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;

[[Page 45601]]

     Otariid pinnipeds in water: Functional hearing is 
estimated to occur between approximately 100 Hz and 40 kHz.
    As mentioned previously in this document, 26 marine mammal species 
(20 cetacean and 6 pinniped species) are likely to occur in the 
proposed seismic survey area. Of the 20 cetacean species likely to 
occur in NSF and ASC's proposed action area, 7 are classified as low-
frequency cetaceans (southern right, humpback, minke, Antarctic minke, 
sei, fin, and blue whale), 12 are classified as mid-frequency cetaceans 
(sperm, Arnoux's beaked, Cuvier's beaked, Shepherd's beaked, southern 
bottlenose, Gray's beaked, strap-toothed beaked, killer, and long-
finned pilot whale, and southern right whale, Peale's, and hourglass 
dolphin), and 1 is classified as a high-frequency cetacean (spectacled 
porpoise) (Southall et al., 2007). Of the 6 pinniped species likely to 
occur in NSF and ASC's proposed action area, 4 are classified as phocid 
pinnipeds (crabeater, leopard, Weddell, and southern elephant seal), 
and 2 are classified as otariid pinnipeds (Antarctic and Subantarctic 
fur 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 survey 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).

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 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

[[Page 45602]]

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 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

[[Page 45603]]

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 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 and beluga whales (Delphinapterus leucas) exhibited

[[Page 45604]]

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 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

[[Page 45605]]

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 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,

[[Page 45606]]

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 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) 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 area. The link 
between the stranding and the seismic surveys was inconclusive and not 
based on any

[[Page 45607]]

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.
    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 acoustic Doppler current profiler 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 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

[[Page 45608]]

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 [mu]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, 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

[[Page 45609]]

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 [mu]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.
Dredging Activities
    During dredging, 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. 
Dredging 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 dredging (NSF/USGS PEIS, 2011). 
NMFS believes that the brief exposure of marine mammals to noise 
created from the mechanical action of the devices for dredging is not 
likely to result in the harassment of marine mammals.
    The dredge would be attached to the main winch cable using a chain 
bridle. To dredge a rocky bottom, the dredge would be lowered slowly to 
the seafloor and the vessel would move slowly down the dredge line 
while paying out on the winch (30 m per minute). Then the vessel would 
hold station while slowly paying in the dredge to obtain the sample. 
This method allows NSF and ASC to manage the tension spikes if the 
dredge gets hung up or skips on the ocean bottom. The mechanical wire 
is protected with a weak link system and the cable is laid over an 
oversized head sheave for proper support of the wire. Each dredging 
effort would require approximately 6 hours; therefore, dredges would be 
in the water for a total of approximately 36 hours. The vessel speed 
would be less than 2 kts during dredge 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 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

[[Page 45610]]

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 
compared to the number of commercial ships 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. This large of an 
array carries the risk of entanglement for marine mammals. 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 entanglement of an olive ridley sea turtle (Lepidochelys 
olivacea) in the R/V 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 not significant because of the vessel speed and the 
monitoring efforts onboard the survey vessel.
    The potential effects to marine mammals described in this section 
of the document do not take into consideration the proposed monitoring

[[Page 45611]]

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 seismic survey is not anticipated to have any 
permanent impact on habitats used by the marine mammals in the proposed 
survey 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 3,953 km\2\ proposed project area, previously discussed 
in this notice.

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 45612]]

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 
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 (Christian et al., 2003, 2004; DFO, 2004) and adult 
cephalopods (McCauley et al.,

[[Page 45613]]

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).

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 
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 shallow, 
intermediate, and deep 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 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). 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

[[Page 45614]]

operations in deep 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 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, 
pygmy and dwarf 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 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 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 operated, ramp-up to full power 
would be permissible 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. A ramp-up from a shut-down may occur at night, but only where 
the exclusion zone is small enough to be visible. 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 during the day or close to the 
vessel at night.

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 accomplishment of one or more of 
the general goals listed below:
    (1) Avoidance of minimization of injury or death of marine mammals

[[Page 45615]]

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 will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present in the proposed action area. 
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 will 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 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 Scotia Sea and southern Atlantic 
Ocean, 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. NSF and ASC would 
appoint the PSOs with NMFS's concurrence. The lead PSO would be 
experienced with marine mammal species in the Scotia Sea, southern 
Atlantic Ocean, 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 
Scotia Sea and southern Atlantic Ocean. Observations would take place 
during ongoing daytime operations and nighttime ramp-ups of the 
airguns. During the majority of seismic operations, at least one PSO 
would be on duty from observation platforms (i.e., the best available 
vantage point on the

[[Page 45616]]

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. 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 daytime, 
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.
    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 daytime periods 
when the Palmer is underway without seismic 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, 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 seismic 
activity.
    5. Data on the behavior and movement patterns of marine mammals 
seen at times with and without seismic activity.

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;
     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 seismic 
operations;
     Sighting rates of marine mammals during periods with and 
without airgun activities (and other variables that could affect 
detectability);
     Initial sighting distances versus airgun activity state;
     Closest point of approach versus airgun activity state;
     Observed behaviors and types of movements versus airgun 
activity state;
     Numbers of sightings/individuals seen versus airgun 
activity state; and
     Distribution around the source vessel versus airgun 
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

[[Page 45617]]

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: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.
    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 
[email protected] and [email protected]. 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.
    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 [email protected] and [email protected]. 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.
    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 
[email protected] and [email protected], 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           180 dB re 1
                                   threshold shift     [micro]Pa-m (root
                                   (PTS) (Any level    means square
                                   above that which    [rms])
                                   is known to cause   (cetaceans)
                                   TTS).              190 dB re 1
                                                       [micro]Pa-m (rms)
                                                       (pinnipeds).
Level B harassment..............  Behavioral          160 dB re 1
                                   disruption (for     [micro]Pa-m
                                   impulsive noise).   (rms).
Level B harassment..............  Behavioral          120 dB re 1
                                   disruption (for     [micro]Pa-m
                                   continuous noise).  (rms).
------------------------------------------------------------------------

    Level B harassment is anticipated and proposed to be authorized as 
a result of the proposed low-energy seismic survey in the Scotia Sea 
and southern Atlantic Ocean. Acoustic stimuli (i.e., increased 
underwater sound) generated during the operation of the seismic airgun 
array 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 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 Scotia Sea and southern 
Atlantic Ocean. The estimates are based on a consideration of the 
number of marine mammals that could be harassed during the 
approximately 325 hours and 2,950 km of seismic airgun operations with 
the two GI airgun array to be used.
    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.

[[Page 45618]]

    There are no stock assessments and very limited population 
information available for marine mammals in the Scotia Sea and southern 
Atlantic Ocean. Published estimates of marine mammal densities are 
limited for the proposed low-energy seismic survey's action area. 
Available density estimates from the Naval Marine Species Density 
Database (NMSDD) (NAVFAC, 2012) were used for 5 mysticetes and eight 
odontocetes. Density of spectacled porpoise was based on the density 
reported in Santora et al. (2009; as reported in NOAA SWFSC, 2013). 
Densities for minke (including the dwarf sub-species) whales and 
Subantarctic fur seals were unavailable and the densities for Antarctic 
minke whales and Antarctic fur seals were used as proxies, 
respectively.
    For other mysticetes and odontocetes, reported sightings data from 
two previous research surveys in the Scotia Sea and vicinity were used 
to identify species that may be present in the proposed action area and 
to estimate densities. While these surveys were not specifically 
designed to quantify marine mammal densities, there was sufficient 
information to develop density estimates. The data collected for the 
two studies were in terms of animals sighted per time unit, and the 
sighting data were then converted to an areal density (number of 
animals per square km) by multiplying the number of animals observed by 
the estimated area observed during the survey.
    Some marine mammals that were present in the area 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 animals.
    Sighting data collected during the 2003 RRS James Clark Ross Cruise 
JR82 (British Antarctic Survey, undated) were used as the basis to 
estimate densities for four species: Southern right whale, southern 
bottlenose whale, hourglass dolphin, and Peale's dolphin. The cruise 
length was 4,143 km (2,237 nmi); however, lateral distance from the 
vessel where cetaceans were viewed was not identified in the report. 
Therefore, it was assumed that all species were sighted within 2.5 km 
(1.4 nmi) of the vessel (5 km [2.7 nmi] width) because this was the 
assumed sighting distance (half strip width). This resulted in a survey 
area of 20,715 km\2\ (6,039 nmi\2\). Density of the strap-toothed 
beaked whale was based on sighting data reported in Rossi-Santos et al. 
(2007). The survey length was 1,296 km (699.8 nmi); however, lateral 
distance from the vessel where cetaceans were sighted was not 
identified in the report. Therefore, it was assumed that all species 
were sighted within 2.5 km of the vessel (5 km width) because this was 
assumed as a conservative distance where cetaceans could be 
consistently observed. This width was needed to calculate densities 
from data sources where only cruise distance and animal numbers were 
available in the best available reports. This resulted in a survey area 
of 6,480 km\2\ (1,889.3 nmi\2\)
    With respect to pinnipeds, one study (Santora et al., 2009 as 
reported in NOAA SWFSC, 2013) provided a density estimate for southern 
elephant seals. No other studies in the region of the Scotia Sea 
provided density estimates for pinnipeds. Therefore, reported sighting 
data from two previous research surveys in the Scotia Sea and vicinity 
were used to identify species that may be present and to estimate 
densities. Sighting data collected during the 2003 RRS James Clark Ross 
Cruise JR82 (British Antarctic Survey, undated) were used as the basis 
to estimate densities for four species: Antarctic fur seal, crabeater 
seal, leopard seal, and Weddell seal. The survey length was 4,143 km 
(1,207.9 nmi); however, lateral distance from the vessel where 
pinnipeds were viewed was not identified in the report. Therefore, it 
was assumed that all species were sighted within 0.4 km (0.2 nmi) of 
the vessel (0.8 km [0.4 nmi] width), based on Southwell et al. (2008). 
This resulted in a survey area of 3,315 km\2\ (966.5 nmi\2\).
    Some pinnipeds that were present in the area during the British 
Antarctic Survey cruise may not have been observed. Therefore, a 
correction factor of 1.66 was applied to the pinniped density 
estimates, which assumes 66% more animals than observed were present 
and potentially may have been in the water. This conservative 
correction factor takes into consideration that pinnipeds are 
relatively difficult to observe in the water due to their small body 
size and surface behavior, and some pinnipeds may not have been 
observed due to poor visibility conditions.
    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; therefore, the pinniped densities have been adjusted 
downward to account for this consideration. Take was not requested for 
Ross seals because preferred habitat for this 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.

[[Page 45619]]



 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)
    During NSF and ASC's Proposed Low-Energy Seismic Survey (Approximately 2,950 km of Tracklines/Approximately 3,953 km\2\ [0.67 km x 2 x 2,950 km]
                     Ensonified Area for Airgun Operations) in the Scotia Sea and Southern Atlantic Ocean, September to October 2014
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Calculated
                                                          take from
                                                       seismic airgun
                                                          operations                                               Approximate
                                           Density         (i.e.,                                                 percentage of
                                        (# of     estimated    Requested take                              population
               Species                    animals/        number of     authorization        Abundance \3\          estimate       Population trend \5\
                                          km\2\)\1\      individuals                                               (requested
                                                         exposed to                                                 take) \4\
                                                        sound levels
                                                        >=160 dB re 1
                                                       [micro]Pa) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
Southern right whale.................       0.0079652              31              31  8,000 to 15,000.........            0.39  Increasing at 7 to 8%
                                                                                                                                  per year.
Humpback whale.......................       0.0006610               3               3  35,000 to 40,000--                  0.03  Increasing.
                                                                                        Worldwide; 9,484--
                                                                                        Scotia Sea and
                                                                                        Antarctica Peninsula.
Antarctic minke whale................       0.1557920             616             616  Several 100,000--                   3.4   Stable.
                                                                                        Worldwide; 18,125--
                                                                                        Scotia Sea and
                                                                                        Antarctica Peninsula.
Minke whale (including dwarf minke          0.1557920             616             616  NA......................           NA     NA.
 whale sub-species).
Sei whale............................       0.0063590              25              25  80,000--Worldwide.......            0.03  NA.
Fin whale............................       0.0182040              72              72  140,000--Worldwide;                 1.54  NA.
                                                                                        4,672--Scotia Sea and
                                                                                        Antarctica Peninsula.
Blue whale...........................       0.0000510               1               1  8,000 to 9,000--                    0.01  NA.
                                                                                        Worldwide.
Odontocetes:
Sperm whale..........................       0.0020690               8               8  360,000--Worldwide;                <0.01  NA.
                                                                                        9,500--Antarctic.
Arnoux's beaked whale................       0.0113790              45              45  NA......................           NA     NA.
Cuvier's beaked whale................        0.000548               3               3  NA......................           NA     NA.
Gray's beaked whale..................       0.0018850               7               7  NA......................           NA     NA.
Shepherd's beaked whale..............       0.0092690              37              37  NA......................           NA     NA.
Strap-toothed beaked whale...........       0.0007716               3               3  NA......................           NA     NA.
Southern bottlenose whale............       0.0089307              35              35  50,000--South of                    0.07  NA.
                                                                                        Antarctic Convergence.
Killer whale.........................       0.0153800              61              61  80,000--South of                    0.08  NA.
                                                                                        Antarctic Convergence.
Long-finned pilot whale..............       0.2145570             848             848  200,000--South of                   0.42  NA.
                                                                                        Antarctic Convergence.
Peale's dolphin......................       0.0026551              10              10  NA--Worldwide; 200--               NA     NA.
                                                                                        southern Chile \3\.                5
Hourglass dolphin....................       0.0154477              61              61  144,000.................            0.04  NA.
Southern right whale dolphin.........       0.0061610              24              24  NA......................           NA     NA.
Spectacled porpoise..................       0.0015000               6               6  NA......................           NA     NA.
Pinnipeds:
Crabeater seal.......................       0.0185313              73              73  5,000,000 to 15,000,000.           <0.01  Increasing.
Leopard seal.........................       0.0115194              46              46  220,000 to 440,000......            0.02  NA.
Weddell seal.........................       0.0027447              11              11  500,000 to 1,000,000....           <0.01  NA.
Southern elephant seal...............       0.0003000               1               1  640,000 to 650,000--               <0.01  Increasing, decreasing,
                                                                                        Worldwide; 470,000--                      or stable depending on
                                                                                        South Georgia Island.                     breeding population.
Antarctic fur seal...................       0.5103608           2,017           2,017  1,600,000 to 3,000,000..            0.13  Increasing.
Subantarctic fur seal................       0.5103608           2,017           2,017  >310,000................            0.65  Increasing.
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ Sightings from a 47 day (7,560 km) period on the RRS James Clark Ross JR82 survey during January to February 2003 and sightings from a 34 day (1,296
  km) period on the Kotic II from January to March 2006.

[[Page 45620]]

 
\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\ 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).
Note: Take was not requested for Ross seals because preferred habitat for these species is not within the proposed action area.

    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 Scotia Sea and southern 
Atlantic Ocean 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 on one or more occasions by considering the 
total marine area that would be within the 160 dB radius around the 
operating airgun array on at least one occasion and the expected 
density of marine mammals in the area (in the absence of the a seismic 
survey). 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 670 m times 2) around the operating airguns. 
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 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 greater than 1,000 m deep, the buffer zone of 670 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 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.
    Applying the approach described above, approximately 3,953 km\2\ 
(including the 25% contingency) would be ensonified within the 160 dB 
isopleth for seismic airgun operations on one or more occasions during 
the proposed 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. 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 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 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, 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 program) 
to occur in the waters that would be exposed to greater than or equal 
to 160 dB (rms) for seismic airgun operations.
    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 
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 middle column 
(fourth from the right) 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. NSF has already prepared a permit 
application for the Government of South Georgia and South Sandwich 
Islands for the proposed research activities, including trawling and 
sampling of the seafloor. The proposed action would complement 
fieldwork studying other Antarctic ice shelves, oceanographic studies, 
and ongoing development of ice sheet and 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 
coastal Antarctica, provide additional data on marine mammals present 
in the Scotia Sea study areas, and communicate its findings 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 will 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 Scotia Sea and southern Atlantic 
Ocean 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.

[[Page 45621]]

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 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 30 
days. Additionally, the 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 26 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 5%). 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, the proposed activity is 
not expected to impact rates of recruitment or survival for any of 
these marine mammal species.
    Of the 26 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 all six 
species. To protect these animals (and other marine mammals in the 
study area), NSF and ASC would be required to cease or reduce airgun 
operations if any marine mammal enters designated 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 [micro]Pa (rms) 
received level threshold for underwater impulse sound levels to 
determine whether take by Level B harassment occurs. Southall et al. 
(2007) provide a severity scale for ranking observed behavioral 
responses of both free-ranging marine mammals and laboratory subjects 
to various types of anthropogenic sound (see Table 4 in Southall et al. 
[2007]). 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 Scotia 
Sea and southern Atlantic Ocean, September to October 2014, may result, 
at worst, in a modification in behavior and/or low-level physiological 
effects (Level B harassment) of certain species of marine mammals.

[[Page 45622]]

    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 26 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 survey (including 
a 25% contingency) are in Table 6 of this document. Of the cetaceans, 
31 southern right, 3 humpback, 616 Antarctic minke, 616 minke, 25 sei, 
72 fin, 1 blue, and 8 sperm whales could be taken by Level B harassment 
during the proposed seismic survey, which would represent 0.39, 0.03, 
3.4, unknown, 0.03, 1.54, and 0.01% of the affected worldwide or 
regional populations, respectively. In addition, 45 Arnoux's beaked, 3 
Cuvier's beaked, 7 Gray's beaked, 37 Shepherd's beaked, 3 strap-toothed 
beaked, and 35 southern bottlenose whales could be taken be Level B 
harassment during the proposed seismic survey, which would represent 
unknown, unknown, unknown, unknown, unknown, and 0.07% of the affected 
worldwide or regional populations, respectively. Of the delphinids, 61 
killer whales, 848 long-finned pilot whales, and 10 Peale's, 61 
hourglass, and 24 southern right whale dolphins, and 6 spectacled 
porpoise could be taken by Level B harassment during the proposed 
seismic survey, which would represent 0.08, 0.42, unknown/5, 0.04, 
unknown, and unknown of the affected worldwide or regional populations, 
respectively. Of the pinnipeds, 73 crabeater, 46 leopard, 11 Weddell, 
and 1 southern elephant seals and 2,017 Antarctic and 2,017 
Subantarctic fur seals could be taken by Level B harassment during the 
proposed seismic survey, which would represent <0.01, 0.02, <0.01, 
<0.01, 0.13, and 0.65 of the affected worldwide or regional population, 
respectively.
    No known current worldwide or regional population estimates are 
available for 9 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, Cuvier's beaked, 
Gray's beaked, Shepherd's beaked, and strap-toothed beaked whales, and 
Peale's and southern right whale dolphins and spectacled porpoises. 
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. Cuvier's beaked 
whales generally occur in deep, offshore waters of tropical to polar 
regions worldwide. They seem to prefer waters over and near the 
continental slope (Jefferson et al., 2008). Gray's beaked whales are 
generally found in deep waters of temperate regions (south of 30[deg] 
South) in the Southern Hemisphere (Jefferson et al., 2008). Shepherd's 
beaked whales are generally found in deep temperate waters (south of 
30[deg] South) of the Southern Hemisphere and are thought to have a 
circumpolar distribution (Jefferson et al., 2008). 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). 
Peale's dolphins generally occur in the waters around the southern tip 
of South America from 33 to 38[deg] South, but may extend to islands 
further south. This species is considered coastal as they are commonly 
found in waters over the continental shelf (Jefferson et al., 2008). 
Southern right whale dolphins are generally found in temperate to 
subantarctic waters (30 to 65[deg] South), with a southern limit 
bounded by the Antarctic Convergence (Jefferson et al., 2008). 
Spectacled porpoises are generally found in subantarctic waters and may 
have a circumpolar distribution in the Southern Hemisphere (as far 
south as 64[deg] South). They have been sighted in oceanic waters, near 
islands, as well as in rivers and channels (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 5%). 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 two other research institutions, 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 will

[[Page 45623]]

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 will 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.

National Environmental Policy Act

    With NSF and ASC's complete application, NSF and ASC provided NMFS 
a ``Draft Initial Environmental Evaluation/Environmental Assessment to 
Conduct a Study of the Role of the Central Scotia Sea and North Scotia 
Ridge in the Onset and Development of the Antarctic Circumpolar 
Current,'' (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. Prior 
to making a final decision on the IHA application, NMFS will either 
prepare an independent EA or, after review and evaluation of the NSF 
and ASC IEE/EA for consistency with the regulations published by the 
Council of Environmental Quality (CEQ) and NOAA Administrative Order 
216-6, Environmental Review Procedures for Implementing the National 
Environmental Policy Act, adopt the NSF and ASC IEE/EA, and decide 
whether or not to issue a Finding of No Significant Impact (FONSI).

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 Scotia Sea and southern Atlantic Ocean, 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 Scotia Sea and southern Atlantic Ocean, September to October 2014:
    1. This Authorization is valid from September 20 through December 
1, 2014.
    2. This Authorization is valid only for NSF and ASC's activities 
associated with low-energy seismic survey, bathymetric profile, GPS 
installation, and dredge sampling operations conducted aboard the 
Palmer that shall occur in the following specified geographic area:
    In selected regions of the Scotia Sea (located northeast of the 
Antarctic Peninsula) and southern Atlantic Ocean off the coast of East 
Antarctica, with a focus on two areas: (1) Between the central rise of 
the Scotia Sea and the East Scotia Sea, and (2) the far South Atlantic 
Ocean immediately northeast of South Georgia toward the Northeast 
Georgia Rise (both encompassing the region between 53 and 58[deg], and 
between 33 and 40[deg] West. Water depths in the survey area are 
expected to be deeper than 1,000 m. The low-energy seismic survey will 
be conducted in the Exclusive Economic Zone (EEZ) for the South Georgia 
and South Sandwich Islands and International Waters (i.e., high seas), 
as specified in NSF and ASC's Incidental Harassment Authorization 
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 Scotia 
Sea and southern Atlantic Ocean:
    (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, 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);
    (b) A multi-beam echosounder;
    (c) A single-beam echosounder;
    (d) An acoustic Doppler current profiler; and
    (e) A sub-bottom profiler.
    5. 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 daytime 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 daytime 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

[[Page 45624]]

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
    (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. See Table 2 (above) for 
distances and exclusion zones.

Visually 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 (day 
or night).
    (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 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 at Night

    (j) Marine seismic surveying may continue into night and 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 at night or 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 Scotia Sea and southern Atlantic Ocean 
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 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 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 
Incidental Harassment Authorization. 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

[[Page 45625]]

comments, the draft report shall be considered to be the final report.

Reporting Prohibited Take

    (c)(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), 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 [email protected] and 
[email protected]. The report must include the following 
information:
    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

    (ii) 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 [email protected] and [email protected]. 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

    (iii) 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 [email protected] and 
[email protected], 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.
    8. Endangered Species Act Biological Opinion and Incidental Take 
Statement
    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.
    9. 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: July 30, 2014.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2014-18396 Filed 8-4-14; 8:45 am]
BILLING CODE 3510-22-P