Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey in the Western Tropical Pacific Ocean, November to December 2011, 68720-68734 [2011-28782]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 76, Number 215 (Monday, November 7, 2011)]
[Notices]
[Pages 68720-68734]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-28782]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XA507


Takes of Marine Mammals Incidental to Specified Activities; Low-
Energy Marine Geophysical Survey in the Western Tropical Pacific Ocean, 
November to December 2011

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

ACTION: Notice; issuance of an incidental take authorization (ITA).

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SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) 
regulation, notification is hereby given that NMFS has issued an 
Incidental Harassment Authorization (IHA) to Scripps Institution of 
Oceanography (SIO) to take marine mammals, by Level B harassment, 
incidental to conducting a low-energy marine geophysical (i.e., 
seismic) survey in the western tropical Pacific Ocean, November to 
December 2011.

DATES: Effective November 5, 2011 through January 31, 2012.

ADDRESSES: A copy of the IHA and application are available by writing 
to P. Michael Payne, Chief, Permits and Conservation Division, Office 
of Protected Resources, National Marine Fisheries Service, 1315 East-
West Highway, Silver Spring, MD 20910 or by telephoning the contacts 
listed here.
    A copy of the IHA application containing a list of the references 
used in this document may be obtained by writing to the above address, 
telephoning the contact listed here (see FOR FURTHER INFORMATION 
CONTACT) or visiting the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    The following associated documents are also available at the same 
Internet address: ``Environmental Assessment Pursuant to the National 
Environmental Policy Act, 42 U.S.C. 4321, et seq. and Executive Order 
12114, Marine Geophysical Survey by the R/V Thompson in the western 
tropical Pacific Ocean, November-December 2011 (EA)'' prepared by the 
National Science Foundation (NSF), and ``Environmental Assessment of a 
Low-Energy Marine Geophysical Survey by the R/V Thompson in the Western 
Tropical Pacific Ocean, November-December 2011,'' prepared by LGL Ltd., 
Environmental Research Associates (LGL), on behalf of NSF. The NMFS 
Biological Opinion will be available online at: https://www.nmfs.noaa.gov/pr/consultation/opinions.htm. Documents cited in this 
notice may be viewed, by appointment, during regular business hours, at 
the aforementioned address.

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

SUPPLEMENTARY INFORMATION:

Background

    Section 101(a)(5)(D) of the MMPA (16 U.S.C. 1371(a)(5)(D)) directs 
the Secretary of Commerce (Secretary) to authorize, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals of a species or population stock, 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, if the 
taking is limited to harassment, a notice

[[Page 68721]]

of a proposed authorization is provided to the public for review.
    Authorization for the incidental taking of small numbers of marine 
mammals shall be granted if NMFS finds that the taking will have a 
negligible impact on the species or stock(s), and will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses (where relevant). The authorization must 
set forth the permissible methods of taking, other means of effecting 
the least practicable impact on the species or stock and its habitat, 
and requirements pertaining to the mitigation, monitoring and reporting 
of such takings. 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' 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

    NMFS received an application on June 14, 2011, from SIO for the 
taking by harassment, of marine mammals, incidental to conducting a 
low-energy marine seismic survey in the western tropical Pacific Ocean. 
SIO, a part of the University of California San Diego, in collaboration 
with University of Washington (UW), Woods Hole Oceanographic 
Institution (WHOI), Texas A&M University (TAMU), and Kutztown 
University, plans to conduct a magnetic and seismic study of the 
Hawaiian Jurassic crust onboard an oceanographic research vessel in the 
western tropical Pacific Ocean north of the Marshall Islands for 
approximately 32 days. The survey will use a pair of Generator Injector 
(GI) airguns each with a discharge volume of 105 cubic inches (in\3\). 
SIO plans to conduct the survey from approximately November 5 to 
December 17, 2011. The seismic survey will be conducted partly in 
international waters and partly in the Exclusive Economic Zone (EEZ) of 
Wake Island (U.S.), and possibly in the EEZ of the Republic of the 
Marshall Islands. On July 29, 2011, NMFS published a notice in the 
Federal Register (76 FR 45518) making preliminary determinations and 
proposing to issue an IHA. The notice initiated a 30-day public comment 
period.
    SIO plans to use one source vessel, the R/V Thomas G. Thompson 
(Thompson) and a seismic airgun array to collect seismic reflection and 
refraction profiles from the Hawaiian Jurassic crust in the western 
tropical Pacific Ocean. In addition to the operations of the seismic 
airgun array, SIO intends to operate a multibeam echosounder (MBES) and 
a sub-bottom profiler (SBP) 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 a short-term behavioral disturbance for marine mammals in the 
survey area. This is the principal means of marine mammal taking 
associated with these activities and SIO has requested an authorization 
to take 19 species of marine mammals by Level B harassment. Take is not 
expected to result from the use of the MBES or SBP, for reasons 
discussed in this notice; nor is take expected to result from collision 
with the vessel because it is a single vessel moving at a relatively 
slow speed during seismic acquisition within the survey, for a 
relatively short period of time (approximately 39 days). It is likely 
that any marine mammal would be able to avoid the vessel.

Description of the Specified Activity

    SIO's planned seismic survey in the western tropical Pacific Ocean, 
as part of an integrated magnetic and seismic study of the Hawaiian 
Jurassic crust, will take place for approximately 32 days in November 
to December 2011 (see Figure 1 of the IHA application). The seismic 
survey will take place in water depths ranging from approximately 2,000 
to 6,000 meters (m) (6,561.7 to 19,685 feet [ft]) and consist of 
approximately 1,600 kilometers (km) (863.9 nautical miles [nmi]) of 
transect lines in the study area. The survey will take place in the 
area 13[deg] to 23[deg] North, 158[deg] to 172[deg] East, just north of 
the Marshall Islands. The project is scheduled to occur from 
approximately November 5 to December 17, 2011. Some minor deviation 
from these dates is possible, depending on logistics and weather.
    The goal of the research is to define the global nature and 
significance of variations in intensity and direction of the Earth's 
magnetic field during the Jurassic time period (approximately 145 to 
180 million years ago), which appears to have been a period of 
sustained low intensity and rapid directional changes or polarity 
reversals compared to other periods in Earth's magnetic field history. 
Access to Jurassic-aged crust with good magnetic signals is very 
limited, with the best continuous records in ocean crust, but only one 
area of the ocean floor has been measured to date: The western Pacific 
Japanese magnetic lineations. To properly assess the global 
significance of the variations and to eliminate local crustal and 
tectonic complications, it is necessary to measure Jurassic magnetic 
signals in a different area of the world. The study will attempt to 
verify the unusual behavior of the Jurassic geomagnetic field and test 
whether it was behaving in a globally coherent way by conducting a 
near-bottom marine magnetic field survey of Pacific Hawaiian Jurassic 
crust located between Hawaii and Guam.
    Widespread, younger, Cretaceous-aged (65 to 140 million years ago) 
volcanism overprinted much of the western Pacific, so it is important 
to know the extent of Cretaceous-aged volcanic crust. This will be 
assessed by carrying out a seismic reflection and refraction survey of 
the Hawaiian Jurassic crust. First, the autonomous underwater vehicle 
(AUV) Sentry and a simultaneously deployed deep-towed magnetometer 
system will acquire two parallel profiles of the near-bottom crustal 
magnetic field 10 km (5.4 nmi) apart and approximately 800 km (432 nmi) 
long. More information on the AUV Sentry is available at https://www.whoi.edu/page.do?pid=38098. Second, the seismic survey will be 
conducted using airguns, a hydrophone streamer, and sonobuoys directly 
over the same profile as the AUV magnetic survey.
    The survey will involve one source vessel, the Thompson. For the 
seismic component of the research program, the Thompson will deploy an 
array of two low-energy Sercel Generator Injector

[[Page 68722]]

(GI) airguns as an energy source (each with a discharge volume of 105 
in\3\) at a tow depth of 3 m (9.8 ft). The acoustic receiving system 
will consist of an 800 m (2,624.7 ft), 48 channel hydrophone streamer 
and directional, passive sonobuoys. Over the course of the seismic 
operations, 50 Ultra Electronics AN/SSQ-53D(3) directional, passive 
sonobuoys will be deployed from the vessel. The sonobuoys consist of a 
hydrophone, electronics, and a radio transmitter. As the airgun is 
towed along the survey lines, the hydrophone streamer and sonobuoys 
will receive the returning acoustic signals and transfer the data to 
the on-board processing system. The seismic signal is measured by the 
sonobuoy's hydrophone and transmitted by radio back to the source 
vessel. The sonobuoys are expendable, and after a pre-determined time 
(usually eight hours), they self-scuttle and sink to the ocean bottom.
    The survey lines will be within the area enclosed by red lines in 
Figure 1 of the IHA application, but the exact locations of the survey 
lines will be determined during transit after observing the location of 
the appropriate magnetic lineation by surface-towed magnetometer. 
Magnetic and seismic data acquisition will alternate on a daily basis; 
seismic surveys will take place while the AUV used to collect magnetic 
data is on deck to recharge its batteries. In addition to the 
operations of the airgun array, a Kongsberg EM300 MBES and ODEC Bathy-
2000 SBP will also be operated from the Thompson continuously 
throughout the cruise. There will be additional seismic operations 
associated with equipment testing, start-up, and possible line changes 
or repeat coverage of any areas where initial data quality is sub-
standard. In SIO's calculations, 25% has been added for those 
contingency operations.
    All planned geophysical data acquisition activities will be 
conducted by technicians provided by SIO, with on-board assistance by 
the scientists who have planned the study. The Principal Investigators 
are Drs. Masako Tominaga, Maurice A. Tivey, Daniel Lizarralde of WHOI, 
William W. Sager of TAMU, and Adrienne Oakley of Kutztown University. 
The vessel will be self-contained, and the crew will live aboard the 
vessel for the entire cruise.

Description of the Dates, Duration, and Specified Geographic Region

    The Thompson is expected to depart Honolulu, Hawaii, on November 5, 
2011 and spend approximately 7 days in transit to the survey area, 32 
days alternating between acquiring magnetic and seismic data, and 
approximately 3 days in transit, arriving at Apra Harbor, Guam, on 
December 17, 2011. Seismic operations will be conducted for a total of 
approximately 16 days. Some minor deviation from this schedule is 
possible, depending on logistics and weather. The survey will encompass 
the area approximately 13[deg] to 23[deg] North, approximately 158[deg] 
to 172[deg] East, just north of the Marshall Islands (see Figure 1 of 
the IHA application). Water depths in the survey area generally range 
from approximately 2,000 to 6,000 m (6,561.7 to 19,685 ft); Wake Island 
is included in the survey area. The seismic survey will be conducted 
partly in international waters and partly in the EEZ of Wake Island 
(U.S.), and possibly in the EEZ of the Republic of the Marshall 
Islands.
    NMFS outlined the purpose of the program in a previous notice for 
the proposed IHA (76 FR 45518, July 29, 2011). The activities to be 
conducted have not changed between the proposed IHA notice and this 
final notice announcing the issuance of the IHA. For a more detailed 
description of the authorized action, including vessel and acoustic 
source specifications, the reader should refer to the proposed IHA 
notice (76 FR 45518, July 29, 2011), the IHA application, EA, and 
associated documents referenced above this section.

Comments and Responses

    A notice of proposed IHA for the SIO seismic survey was published 
in the Federal Register on July 29, 2011 (76 FR 45518). During the 30-
day public comment period, NMFS received comments from the Marine 
Mammal Commission (Commission) and approximately 72 private citizens. 
Several of the private citizens' comments were non-substantive and/or 
opposed the issuance of an IHA without providing any specific rationale 
for that position. NMFS, therefore, is not providing a substantive 
response to those comments. The Commission's and private citizens' 
comments are online at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Following are their substantive comments and NMFS's 
response:
    Comment 1: The Commission recommends that NMFS require SIO to re-
estimate the proposed exclusion and buffer zones for the two airgun 
array and associated numbers of marine mammal takes using operational 
and site-specific environmental parameters. If the exclusion zones (EZ) 
and buffer zones are not re-estimated for the two airgun array, require 
SIO to provide a detailed justification for basing the EZs and buffer 
zones for the proposed survey in the western tropical Pacific Ocean on 
modeling that relies on measurements from the GOM.
    Response: NMFS is satisfied that the data supplied are sufficient 
for NMFS to conduct its analysis and make any determinations and 
therefore no further effort is needed by the applicant. While exposures 
of marine mammals to acoustic stimuli are difficult to estimate, NMFS 
is confident that the levels of take provided by SIO in their IHA 
application and EA, and authorized herein are estimated based upon the 
best available scientific information and estimation methodology.
    Received sound levels have been modeled by L-DEO for a number of 
airgun configurations, including two 105 in\3\ (210 in\3\ total volume) 
GI airguns, in relation to distance and direction from the airguns (see 
Figure 2 of the IHA application). 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 source where 
sound levels are predicted to be 190, 180, and 160 dB re 1 [micro]Pa 
(rms) in deep water were determined (see Table 3 below).
    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 36 airgun array are not relevant for the two GI 
airguns to be used in the survey. 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, SIO proposes to use the EZ 
predicted by L-DEO's model for the GI airgun operations in deep water, 
although they are likely conservative given the empirical results for 
the other arrays.
    NMFS is confident in the peer-reviewed results of L-DEO's seismic 
calibration studies, which although viewed as conservative, were used 
to determine the sound radii for the mitigation airgun for this cruise 
and which factor into exposure estimates. NMFS had determined that 
these reviews are the best scientific data available for review of the 
IHA application and to support the necessary analyses and 
determinations under the MMPA, Endangered Species Act of 1973 (ESA; 16 
U.S.C. 1531 et seq.), and NEPA. Further, the 160 dB (i.e., buffer)

[[Page 68723]]

zone used to estimate exposure is appropriate and sufficient for 
purposes of supporting NMFS's analysis and determinations required 
under section 101(a)(5)(D) of the MMPA and its implementing 
regulations.
    Although, the L-DEO model does not account for site-specific 
environmental conditions, sound propagation varies notably less between 
deep water sites than it would between shallow water sites (because of 
the reduced significance of bottom interaction), thus decreasing the 
importance of deep water site-specific estimates, such as in this 
seismic survey. Further, the calibration study of the L-DEO model 
predicted that using site-specific information may actually provide 
less conservative EZs at greater distances. At this point in time, the 
alternative method of conducing site-specific attenuation measurements 
in the water depths that the survey is to be conducted is neither 
warranted nor practical for the applicant, both logistically and 
financially. Should the applicant endeavor to undertake a sound source 
verification study in the future, confidence in the results is 
necessary to ensure that appropriate monitoring and mitigation measures 
are implemented; therefore inappropriate or poorly executed efforts 
should be avoided and discouraged.
    Based on NMFS's analysis of the likely effects of the specified 
activity on marine mammals and their habitat, NMFS has determined that 
the EZs identified in the IHA are appropriate for the survey and that 
additional field measurement is not necessary at this time. While 
exposures of marine mammals to acoustic stimuli are difficult to 
estimate, NMFS is confident that the levels of take authorized herein 
are estimated based upon the best available scientific information and 
estimation methodology. The 160 dB zone used to estimate exposure is 
appropriate and sufficient for purposes of supporting NMFS's analysis 
and determinations required under section 101(a)(5)(D) of the MMPA and 
its implementing regulations. The IHA issued to SIO provides monitoring 
and mitigation requirements to protect marine mammals from injury 
(Level A harassment), serious injury, or mortality. SIO is required to 
comply with the IHA's requirements.
    Comment 2: The Commission recommends that NMFS require SIO to use 
operational and site-specific environmental parameters to estimate the 
EZ, buffer zone, and number of marine mammal takes associated with use 
of the SBP and to incorporate those EZ and buffer zones into the same 
type of mitigation and monitoring measures for the SBP as are proposed 
for the two airgun array.
    Response: The notice of the proposed IHA included a discussion of 
the acoustic source specifications and the potential effect of the MBES 
and SBP. The MBES and SBP have anticipated radii of influence 
significantly less than that for the airgun array. The 160 dB (rms) and 
180 dB (rms) isopleths of the MBES and SBP are very small and the 
acoustic beams are very narrow, making the duration of the exposure and 
the potential for taking marine mammals by Level B harassment small to 
non-existent. NMFS believes that it is unlikely that marine mammals 
would be affected by SBP signals whether operating alone or in 
conjunction with other acoustic devices, since the animals would need 
to swim adjacent to the vessel or directly under the vessel. Therefore, 
operation of the SBP does not warrant take requests, or consultation, 
under the MMPA. SIO will already be monitoring and mitigating the EZ 
for the two airgun array which would encompass the small EZ for the 
SBP, therefore it is not logical to use sparse agency resources to 
perform additional, unwarranted modeling.
    Comment 3: The Commission recommends that NMFS condition the IHA to 
prohibit a 15 min pause and require a longer pause before ramping-up 
after a power-down or shut-down of the airguns, based on the presence 
of a mysticete or large odontocete in the EZ and the Thompson's 
movement (speed and direction).
    Response: Although power-down procedures are often standard 
operating practice for seismic surveys, power-downs from two airguns to 
one airgun will not be implemented as a mitigation measure for this 
particular seismic survey, as it will only make a small difference in 
the 180 or 190 dB (rms) radius--probably not enough to allow continued 
single airgun operations if a marine mammal came within the EZ for two 
airguns.
    During periods of active seismic operations, there are occasions 
when the airguns need to be temporarily shut-down (for example due to 
equipment failure, maintenance, or shut-down). In these instances, 
should the airguns be inactive for more than 15 min, then SIO would 
follow the ramp-up procedures identified in the ``Mitigation'' section 
of this document (see below) and IHA where airguns will be re-started 
beginning with a single GI airgun (105 in\3\) and the second GI airgun 
(105 in\3\) will be added after five min. The extended period of 15 min 
before ramping-up after a shut-down of the airguns is operationally 
motivated. Protected Species Observers (PSOs) are primarily concerned 
with marine mammals entering the EZs. However, their visual 
observations go to the horizon or as far as they can practically watch. 
The horizon is approximately 6 nmi at the height of the PSOs watch 
station. The planned survey speed for the cruise is 5 knots; the ship 
would move 2.3 km (1.25 nmi) in 15 min, or roughly \1/5\ the distance 
to the horizon. An alert PSO should be able to say with a reasonable 
degree of confidence whether a marine mammal would be encountered 
within this distance. Thus, a routine ramp-up within 15 min and with 
the PSO on watch should pose little risk to marine mammals.
    Operationally, it would take 15 min or longer to locate the second 
PSO and get him or her into position on the ship's deck to monitor for 
the initial ramp-up procedure or 30 min of observation by two PSOs 
prior to energizing the sound source; thus, the use of an extended 
shut-down period of 15 min before requiring an initial ramp-up 
procedure.
    Comment 4: The Commission recommends that NMFS extend the 30 min 
monitoring period following a marine mammal sighting in the EZ to cover 
the full dive times of all species likely to be encountered.
    Response: NMFS recognizes that several species of deep-diving 
cetaceans are capable of remaining underwater for more than 30 min 
(e.g., sperm whales, Cuvier's beaked whales, Longman's beaked whales, 
Blainville's beaked whales, and Ginkgo-toothed beaked whales); however, 
for the following reasons NMFS believes that 30 min is an adequate 
length for the monitoring period prior to the ramp-up of airguns:
    (1) Because the Thompson is required to monitor before ramp-up of 
the airgun array, the time of monitoring prior to the start-up of the 
two GI airgun array is effectively longer than 30 min (ramp-up will 
begin with one airgun and the second airgun will be added five min 
later);
    (2) In many cases PSOs are observing during times when SIO is not 
operating the seismic airguns and would observe the area prior to the 
30-min observation period;
    (3) The majority of the species that may be exposed do not stay 
underwater more than 30 min; and
    (4) All else being equal and if deep-diving individuals happened to 
be in the area in the short time immediately prior to the pre-ramp-up 
monitoring, if an animal's maximum underwater dive time is 45 min, then 
there is only a one in three chance that the last random surfacing 
would occur prior to the beginning of the required 30 min

[[Page 68724]]

monitoring period and that the animal would not be seen during that 30 
min period.
    Finally, seismic vessels are moving continuously (because of the 
long, towed array and streamer) and NMFS believes that unless the 
animal submerges and follows at the speed of the vessel (highly 
unlikely, especially when considering that a significant part of their 
movement is vertical [deep-diving]), the vessel will be far beyond the 
length of the EZ within 30 min, and therefore it will be safe to start 
the airguns again.
    The effectiveness of monitoring is science-based, and monitoring 
and mitigation measures must be ``practicable.'' NMFS believes that the 
framework for visual monitoring will: (1) Be effective at spotting 
almost all species for which take is requested; and (2) that imposing 
additional requirements, such as those suggested by the Commission, 
would not meaningfully increase the effectiveness of observing marine 
mammals approaching or entering the EZs and thus further minimize the 
potential for take.
    Comment 5: The Commission recommends that NMFS condition the IHA to 
require SIO to monitor, document, and report observations during all 
ramp-up procedures.
    Response: The IHA requires that PSOs on the Thompson make 
observations for 30 min prior to ramp-up, during all ramp-ups, and 
during all daytime seismic operations and record the following 
information when a marine mammal is sighted:
    (i) Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from the seismic vessel, sighting 
cue, apparent reaction of 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 wind force and sea state, visibility, and sun 
glare.
    Comment 6: The Commission recommends that NMFS work with NSF to 
analyze data on ramp-up procedures to help determine the effectiveness 
of those procedures as a mitigation measure for geophysical surveys 
after the data are compiled and quality control measures have been 
completed.
    Response: One of the primary purposes of monitoring is to result in 
``increased knowledge of the species'' and the effectiveness of 
required monitoring and mitigation measures; the effectiveness of ramp-
up as a mitigation measure and marine mammal reaction to ramp-up would 
be useful information in this regard. NMFS has asked NSF and SIO to 
gather all data that could potentially provide information regarding 
the effectiveness of ramp-up as a mitigation measures. However, 
considering the low numbers of marine mammal sightings and low numbers 
of ramp-ups, it is unlikely that the information will result in any 
statistically robust conclusions for this particular seismic survey. 
Over the long term, these requirements may provide information 
regarding the effectiveness of ramp-up as a mitigation measure, 
provided animals are detected during ramp-up.
    Comment 7: Numerous private citizens state that NMFS's proposed IHA 
for the take, by Level B harassment, of 19 species of marine mammals 
incidental to SIO's low-energy seismic survey in the western tropical 
Pacific Ocean is extremely negligent and disturbing considering today's 
knowledge about the impact sound has on ocean inhabitants, and 
particularly marine mammals like whales and dolphins. One private 
citizen interested in marine mammal and seismic issues stated many of 
the potential threats and impacts (i.e., avoidance, fleeing important 
habitat, stress, shifts in migration routes, other forms of behavioral 
responses, and physical damage) from seismic exploration (for 
scientific research or oil and gas purposes) to marine mammals as well 
as to cephalopods, crustaceans, sea turtles, and fishing. The private 
citizen also noted the lack of knowledge and difficulties in studying 
the biology of marine mammals and estimating the impacts of noise on 
these animals.
    Last year, NMFS issued Letters of Authorization (LOAs) to the U.S. 
Navy for the incidental take of millions of marine mammals. Since these 
LOAs were issued, multiple stranding incidents of marine mammals have 
occurred along U.S. coastlines due to explosives, sonar, and now this 
seismic survey. There have been other incidents in this area that have 
not been made public and others that are undocumented.
    In addition to this specified activity, the cetaceans of the 
western tropical Pacific Ocean are impacted from explosives, sonar, 
pollution, fishing nets and trawls, ship collisions, noise produced by 
ships, and other scientific and military activities. Whales and 
dolphins, many species which are already endangered, are essential to 
the oceans biodiversity, health, and safety. Also, sound pollution 
should start being reduced as it contaminates the ocean and interferes 
with the ability of sea creatures to persist. Leading scientific 
research institutions, such as SIO, should be aware of information 
regarding the current and increasing anthropogenic impacts upon ocean 
ecosystems. The private citizens oppose the issuance of an IHA to SIO 
for conducting a low-energy marine seismic survey in the western 
tropical Pacific Ocean. One private citizen states that NOAA must 
prevent by denial, all applications that cause intrusive sound waves 
into an already confusing and damaging array of anthropogenic created 
wave forms.
    Response: As noted above, the purpose of the seismic survey is to 
support research activities to define the global nature and 
significance of variations in intensity and direction of the Earth's 
magnetic field during the Jurassic time period (approximately 145 to 
180 million years ago), which appears to have been a period of 
sustained low intensity and rapid directional changes or polarity 
reversals compared to other period in Earth's magnetic field history. 
SIO's seismic survey is neither oil and gas-related exploration nor a 
military readiness activity.
    Although several commenter's cited many of the potential negative 
aspects of the introduction of anthropogenic sound in the marine 
environment, specific issues related to the content of this IHA request 
were not necessarily made and therefore proves challenging for NMFS to 
provide a response. The notice of the proposed IHA (76 FR 45518, July 
29, 2011) included a discussion of the effects of sounds from airguns 
on mysticetes, odontocetes, and pinnipeds including tolerance, masking, 
behavioral disturbance, hearing impairment, and other non-auditory 
physical effects. Also, NMFS included a detailed discussion of the 
potential effects of this action on marine mammal habitat, including 
physiological and behavioral effects on marine fish, fisheries, and 
invertebrates. While NMFS anticipates that the specified activity may 
result in marine mammals avoiding certain areas due to temporary 
ensonification, this impact to habitat is temporary and reversible 
which NMFS considered in further detail in the notice of the proposed 
IHA (76 FR 45518, July 29, 2011) as behavioral modification. The main 
impact associated with the activity would be temporarily elevated noise 
levels and the associated direct effects on marine mammals. NMFS refers 
the reader to SIO's application and EA for additional information on

[[Page 68725]]

the potential behavioral reactions (or lack thereof) by all types of 
marine mammals to seismic research activities.
    The U.S. Navy's training operations are considered military 
readiness activities. The National Defense Authorization Act of 2004 
(NDAA) (Pub. L. 108-36) modified the MMPA by removing the ``small 
numbers'' and ``specified geographic region'' limitations and amended 
the definition of ``harassment'' as it applies to a ``military 
readiness activity.'' NMFS is unaware of marine mammal strandings along 
U.S. coastlines since these LOAs were issued that have been directly 
associated with to the U.S. Navy's use of sonar or from seismic airguns 
operated by academic institutions. NMFS's Marine Mammal Health and 
Stranding Response Program responds to marine mammals that have 
stranded along the U.S. coastline and assesses trends in marine mammal 
health and how these trends correlate with environmental data.
    To meet NEPA requirements, NSF prepared an ``Environmental 
Assessment Pursuant to the National Environmental Policy Act, 42 U.S.C. 
4321, et seq. and Executive Order 12114, Marine Geophysical Survey by 
the R/V Thompson in the western tropical Pacific Ocean, November-
December 2011,'' which incorporated an ``Environmental Assessment of a 
Low-Energy marine Geophysical Survey by the R/V Thompson in the Western 
Tropical Pacific Ocean, November-December 2011,'' prepared by LGL, 
which included an analysis on the cumulative impacts on the environment 
that result from a combination of past, existing, and reasonably 
foreseeable projects and human activities. Human activities in and near 
the survey area include commercial vessel traffic (including collisions 
with vessels and vessel noise), U.S. military training exercises, 
commercial fishing (entanglement in fishing gear), and coastal 
development associated with military requirements.
    Generally, under the MMPA, NMFS shall authorize the harassment of 
small numbers of marine mammals incidental to an otherwise lawful 
activity, provided NMFS finds that the taking will have a negligible 
impact on the species or stock, will not have an unmitigable adverse 
impact on the availability of the species or stock 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 to achieve the least practicable adverse 
impact. SIO has applied for an IHA and has met the necessary 
requirements for issuance of an IHA for small numbers of marine 
mammals, by Level B harassment, incidental to the low-energy marine 
seismic survey in the western tropical Pacific Ocean.
    No injuries, serious injuries, or mortalities are anticipated to 
occur as a result of SIO's planned low-energy marine seismic survey in 
the western tropical Pacific Ocean, and none are authorized by NMFS in 
IHA issued to SIO. Only short-term, behavioral disturbance is 
anticipated to occur due to the brief and sporadic duration of the 
survey activities. NMFS has determined, provided that the mitigation 
and monitoring measures described below are implemented, that the 
impact of conducting a marine seismic survey in the western tropical 
Pacific Ocean, November to December, 2011, may result, at worst, in a 
temporary modification in behavior and/or low-level physiological 
effects (Level B harassment) of small numbers of certain species of 
marine mammals.
    Based on the analysis contained in the IHA application, notice of 
the proposed IHA (76 FR 45518, July 29, 2011), and this document, of 
the likely effects of the specified activity on marine mammals and 
their habitat, which is based on the best scientific information 
available, and taking into consideration the implementation of the 
mitigation and monitoring measures, NMFS finds that SIO's planned 
research activities, will result in the incidental take of small 
numbers of marine mammals, by Level B harassment only, and that the 
total taking from the marine seismic survey will have a negligible 
impact on the affected species or stocks of marine mammals; and that 
impacts to affected species or stocks of marine mammals have been 
mitigated to the lowest level practicable. Therefore, NMFS shall issue 
the IHA to SIO.

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

    Twenty-six marine mammal species (19 odontocetes, 6 mysticetes, and 
one pinniped) are known to or could occur in the Marshall Islands 
Marine Eco-region (MIME) study area. Several of these species are 
listed as endangered under the U.S. Endangered Species Act of 1973 
(ESA; 16 U.S.C. 1531 et seq.), including the humpback (Megaptera 
novaeangliae), sei (Balaenoptera borealis), fin (Balaenoptera 
physalus), blue (Balaenoptera musculus), and sperm (Physeter 
macrocephalus) whales, as well as the Hawaiian monk seal (Monachus 
schauinslandi). The North Pacific right whale (Eubalaena japonica), 
listed as endangered under the ESA, was historically distributed 
throughout the North Pacific Ocean north of 35[deg] North and 
occasionally occurred as far south as 20[deg] North. Whaling records 
indicate that the MIME was not part of its range (Townsend, 1935).
    The dugong (Dugong dugon), also listed as endangered under the ESA, 
is distributed in shallow coastal waters throughout most of the Indo-
Pacific region between approximately 27[deg] North and South of the 
equator (Marsh, 2008). Its historical range extended to the Marshall 
Islands (Nair et al., 1975). However, the dugong is declining or 
extinct in at least one third of its range and no longer occurs in the 
MIME (Marsh, 2008). The dugong is managed by the U.S. Fish and Wildlife 
Service (USFWS) and is not considered further in this analysis; all 
others are managed by NMFS.
    The marine mammals that occur in the survey area belong to three 
taxonomic groups: Odontocetes (toothed cetaceans, such as dolphins), 
mysticetes (baleen whales), and pinnipeds (seals, sea lions, and 
walrus). Cetaceans are the subject of the IHA application to NMFS.
    Table 1 (below) presents information on the abundance, 
distribution, population status, conservation status, and density of 
the marine mammals that may occur in the survey area during November to 
December 2011.

  Table 1--The Habitat, Regional Abundance, and Conservation Status of Marine Mammals That May Occur in or Near the Seismic Survey Area in the Western
                                                                 Tropical Pacific Ocean
                                          [See text and Tables 2 to 3 in SIO's application for further details]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                        Density (/1,000 km\2\)
             Species                     Habitat         Regional abundance            ESA \1\                      MMPA \2\           CNMI, Hawaii, and
                                                                \4\                                                                         mean \3\
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:

[[Page 68726]]

 
    Humpback whale (Megaptera      Mainly nearshore,    20,800 \5\.........  EN                           D                                            0
     novaeangliae).                 banks.                                                                                                             0
                                                                                                                                                       0
    Minke whale (Balaenoptera      Pelagic and coastal  25,000 \6\.........  NL                           NC                                           0
     acutorostrata).                                                                                                                                   0
                                                                                                                                                       0
    Bryde's whale (Balaenoptera    Pelagic and coastal  20,000 to 30,000...  NL                           NC                                        0.41
     edeni).                                                                                                                                        0.21
                                                                                                                                                     0.3
    Sei whale (Balaenoptera        Primarily offshore,  7,260 to 12,620 \9\  EN                           D                                         0.29
     borealis).                     pelagic.                                                                                                           0
                                                                                                                                                    0.13
    Fin whale (Balaenoptera        Continental slope,   13,620 to 18,680     EN                           D                                            0
     physalus).                     pelagic.             \9\.                                                                                          0
                                                                                                                                                       0
    Blue whale (Balaneoptera       Pelagic, shelf,      NA.................  EN                           D                                            0
     musculus).                     coastal.                                                                                                           0
                                                                                                                                                       0
Odontocetes:
    Sperm whale (Physeter          Pelagic, deep sea..  29,674 \10\........  EN                           D                                         1.23
     macrocephalus).                                                                                                                                3.03
                                                                                                                                                    2.22
    Pygmy sperm whale (Kogia       Deep waters off the  NA.................  NL                           NC                                           0
     breviceps).                    shelf.                                                                                                          3.19
                                                                                                                                                    1.76
    Dwarf sperm whale (Kogia       Deep waters off the  11,200.............  NL                           NC                                           0
     sima).                         shelf.                                                                                                          7.82
                                                                                                                                                    4.30
    Cuvier's beaked whale          Pelagic............  20,000.............  NL                           NC                                           0
     (Ziphius cavirostris).                                                                                                                         6.80
                                                                                                                                                    3.74
    Longman's beaked whale         Deep water.........  NA.................  NL                           NC                                           0
     (Indopacetus pacificus).                                                                                                                       0.45
                                                                                                                                                    0.25
    Blainville's beaked whale      Pelagic............  25,300 \11\........  NL                           NC                                           0
     (Mesoplodon densirostris).                                                                                                                     1.28
                                                                                                                                                     0.7
    Ginkgo-toothed beaked whale    Pelagic............  NA.................  NL                           NC                                           0
     (Mesoplodon ginkgodens).                                                                                                                          0
                                                                                                                                                       0
    Rough-toothed dolphin (Steno   Deep water.........  146,000............  NL                           NC                                        0.29
     bredanensis).                                                                                                                                  3.12
                                                                                                                                                    1.85
    Bottlenose dolphin (Tursiops   Coastal, oceanic,    243,500............  NL                           NC                                        0.21
     truncatus).                    shelf break.                                                          D--Western                                1.23
                                                                                                          North Atlantic coastal                    0.77
    Pantropical spotted dolphin    Coastal and pelagic  800,000 \12\.......  NL                           NC                                        22.6
     (Stenella attenuata).                                                                                D                                         2.10
                                                                                                          (Northeastern offshore)                  11.32
    Spinner dolphin (Stenella      Coastal and pelagic  800,000 \13\.......  NL                           NC                                        3.14
     longirostris).                                                                                       D--Eastern                                0.83
                                                                                                                                                    1.87
    Striped dolphin (Stenella      Off continental      1,000,000 \14\.....  NL                           NC                                        6.16
     coeruleoalba).                 shelf.                                                                                                          5.57
                                                                                                                                                    5.84
    Fraser's dolphin               Deep water.........  289,000............  NL                           NC                                           0
     (Lagenodelphis hosei).                                                                                                                         4.57
                                                                                                                                                    2.51
    Risso's dolphin (Grampus       Deep water,          175,000............  NL                           NC                                           0
     griseus).                      seamounts.                                                                                                      0.83
                                                                                                                                                    0.46
    Melon-headed whale             Oceanic............  45,000.............  NL                           NC                                        4.28
     (Peponocephala electra).                                                                                                                       1.32
                                                                                                                                                    2.67
    Pygmy killer whale (Feresa     Deep, pantropical    39,000.............  NL                           NC                                        0.14
     attenuata).                    waters.                                                                                                            0
                                                                                                                                                    0.06
    False killer whale (Pseudorca  Pelagic............  40,000.............  NL                           NC                                        1.11
     crassidens).                                                            Proposed EN--insular                                                   0.11
                                                                              Hawaiian                                                              0.57
    Killer whale (Orcinus orca)..  Pelagic, shelf,      8,500..............  NL                           NC                                           0
                                    coastal.                                 EN--Southern resident)       D--Southern resident, AT1                 0.16
                                                                                                           transient                                0.09

[[Page 68727]]

 
    Short-finned pilot whale       Pelagic, shelf       500,000 \14\.......  NL                           NC                                        1.59
     (Globicephala macrorhynchus).  coastal.                                                                                                        2.54
                                                                                                                                                    2.11
Pinnipeds:
    Hawaiian monk seal (Monachus   Coastal and pelagic  1,129 \15\.........  EN                           D                                           NA
     schauinslandi).
--------------------------------------------------------------------------------------------------------------------------------------------------------
N.A. Not available or not assessed.
\1\ U.S. Endangered Species Act: EN = Endangered, T = Threatened, NL = Not listed.
\2\ U.S. Marine Mammal Protection Act: D = Depleted, NC = Not Classified.
\3\ CNMI, Hawaii, and mean density estimates as listed in Table 3 of the application.
\4\ Eastern Tropical Pacific in 1986 to 1990 (Wade and Gerrodette, 1993) unless otherwise indicated.
\5\ North Pacific (Barlow et al., 2009).
\6\ Northwest Pacific and Okhotsk Sea (IWC, 2007a).
\7\ North Pacific (Jefferson et al., 2008).
\8\ North Pacific (Tillman, 1977).
\9\ North Pacific (Ohsumi and Wada, 1974).
\10\ Western North Pacific (Whitehead, 2002a).
\11\ Eastern Tropical Pacific (ETP); all Mesoplodon spp. (Wade and Gerrodette, 1993).
\12\ Western/Southern Offshore Stock in ETP in 2000 (Jefferson et al., 2008).
\13\ ETP in 2000 (Jefferson et al., 2008).
\14\ ETP (Jefferson et al., 2008).
\15\ Entire species (Caretta et al., 2010).

    Refer to section III and IV of SIO's application for detailed 
information regarding the abundance and distribution, population 
status, and life history and behavior of these species and their 
occurrence in the project area. The application also presents how SIO 
calculated the estimated densities for the marine mammals in the survey 
area. NMFS has reviewed these data and determined them to be the best 
available scientific information for the purposes of the IHA.

Potential Effects 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 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 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, some behavioral disturbance is 
expected, but NMFS expects the disturbance to be localized and short-
term.
    The notice of the proposed IHA (76 FR 45518, July 29, 2011) 
included a discussion of the effects of sounds from airguns on 
mysticetes, odontocetes, and pinnipeds including tolerance, masking, 
behavioral disturbance, hearing impairment, and other non-auditory 
physical effects. NMFS refers the reader to SIO's application and EA 
for additional information on the behavioral reactions (or lack 
thereof) by all types of marine mammals to seismic vessels.

Anticipated Effects on Marine Mammal Habitat, Fish, Fisheries, and 
Invertebrates

    NMFS included a detailed discussion of the potential effects of 
this action on marine mammal habitat, including physiological and 
behavioral effects on marine fish, fisheries, and invertebrates in the 
notice of the proposed IHA (76 FR 45518, July 29, 2011). While NMFS 
anticipates that the specified activity may result in marine mammals 
avoiding certain areas due to temporary ensonification, this impact to 
habitat is temporary and reversible which NMFS considered in further 
detail in the notice of the proposed IHA (76 FR 45518, July 29, 2011) 
as behavioral modification. The main impact associated with the 
activity would be temporarily elevated noise levels and the associated 
direct effects on marine mammals.
    Recent work by Andre et al. (2011) purports to present the first 
morphological and ultrastructural evidence of massive acoustic trauma 
(i.e., permanent and substantial alterations of statocyst sensory hair 
cells) in four cephalopod species subjected to low-frequency sound. The 
cephalopods, primarily cuttlefish, were exposed to continuous 40 to 400 
Hz sinusoidal wave sweeps (100% duty cycle and 1 s sweep period) for 
two hours while captive in relatively small tanks (one 2,000 liter [L, 
2 m\3\] and one 200 L [0.2 m\3\] tank). The received SPL was reported 
as 157  5 dB re 1 [mu]Pa, with peak levels at 175 dB re 1 
[mu]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.

Mitigation

    In order to issue an 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 subsistence uses.
    SIO has based the mitigation measures described herein, to be 
implemented for the seismic survey, on the following:
    (1) Protocols used during previous SIO seismic research cruises as 
approved by NMFS;

[[Page 68728]]

    (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, SIO and/or its designees shall 
implement the following mitigation measures for marine mammals:
    (1) Exclusion zones;
    (2) Speed or course alteration;
    (3) Shut-down procedures; and
    (4) Ramp-up procedures.
    Exclusion Zones--Received sound levels have been modeled by L-DEO 
for a number of airgun configurations, including two 105 in\3\ GI 
airguns, in relation to distance and direction from the airguns (see 
Figure 2 of the IHA application). 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 source where 
sound levels are predicted to be 190, 180, and 160 dB re 1 [mu]Pa (rms) 
in deep water were determined (see Table 2 below).
    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 36 airgun array are not relevant for the two GI 
airguns to be used in the survey. 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, SIO proposes to use the EZ 
predicted by L-DEO's model for the GI airgun operations in deep water, 
although they are likely conservative give the empirical results for 
the other arrays.
    The 180 and 190 dB radii are shut-down criteria applicable to 
cetaceans and pinnipeds, respectively, as specified by NMFS (2000); 
these levels were used to establish the EZs. If the PSO detects marine 
mammal(s) within or about to enter the appropriate EZ, the airguns will 
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 
GI airgun array operating in deep water depths. Table 2. Distances to 
which sound levels >= 190, 180, and 160 dB re 1 [mu]Pa (rms) could be 
received in deep water during the seismic survey in the western 
tropical Pacific Ocean, November to December, 2011. Distances are based 
on model results provided by L-DEO.

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                            Predicted RMS radii distances (m)
              Source and volume                 Tow depth  (m)          Water depth  (m)        --------------------------------------------------------
                                                                                                       190 dB             180 dB             160 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Two GI airguns (105 in\3\)..................                 3   Deep (>= 1,000)...............                20                 70                670
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Speed or Course Alteration--If a marine mammal is detected outside 
the EZ and, based on its position and the relative motion, is likely to 
enter the EZ, the vessel's speed and/or direct course could be changed. 
This would be done if operationally practicable while minimizing the 
effect on the planned science objectives. The activities and movements 
of the marine mammal (relative to the seismic vessel) will then be 
closely monitored to determine whether the animal is approaching the 
applicable EZ. If the animal appears likely to enter the EZ, further 
mitigative actions will be taken, i.e., either further course 
alterations or a shut-down of the seismic source. Typically, during 
seismic operations, the source vessel is unable to change speed or 
course and one or more alternative mitigation measures will need to be 
implemented.
    Shut-down Procedures--If a marine mammal is seen outside the EZ for 
the airgun(s), and if the vessel's speed and/or course cannot be 
changed to avoid having the animal enter the EZ, the seismic source 
will be shut-down before the animal is within the EZ. If a marine 
mammal is already within the EZ when first detected, the seismic source 
will be shut-down immediately.
    Following a shut-down, SIO will not resume airgun activity until 
the marine mammal has cleared the EZ. SIO will consider the animal to 
have cleared the EZ if:
     A PSO has visually observed the animal leave the EZ, or
     A PSO has not sighted the animal within the EZ for 15 min 
for species with shorter dive durations (i.e., small odontocetes or 
pinnipeds), or 30 min for species with longer dive durations (i.e., 
mysticetes and large odontocetes, including sperm, killer, and beaked 
whales).
    Ramp-up Procedures--SIO will 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. SIO proposes 
that, for the present cruise, this period would be approximately 15 
min. SIO has used similar periods (approximately 15 min) during 
previous SIO surveys.
    Ramp-up will begin with a single GI airgun (105 in\3\). The second 
GI airgun (105 in\3\) will be added after five min. During ramp-up, the 
Protected Species Observers (PSOs) will monitor the EZ, and if marine 
mammals are sighted, SIO will implement a shut-down as though both GI 
airguns were operational.
    If the complete EZ has not been visible for at least 30 min prior 
to the start of operations in either daylight or nighttime, SIO will 
not commence the ramp-up. If one airgun has operated, ramp-up to full 
power will be pe