[Federal Register Volume 78, Number 181 (Wednesday, September 18, 2013)]
[Notices]
[Pages 57354-57368]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-22671]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC624


Takes of Marine Mammals Incidental to Specified Activities; Low-
Energy Marine Geophysical Survey in the Tropical Western Pacific Ocean, 
September to October 2013

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) 
regulations, notification is hereby given that NMFS has issued an 
Incidental Harassment Authorization (IHA) to the Scripps Institution of 
Oceanography (SIO), a part of the University of California at San 
Diego, to take marine mammals, by Level B harassment, incidental to 
conducting a low-energy marine geophysical (seismic) survey in the 
tropical western Pacific Ocean, September to October 2013.

DATES: Effective September 6 through November 12, 2013.

ADDRESSES: A copy of the final 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 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: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    An ``Environmental Analysis of a Low-Energy Marine Geophysical 
Survey by the R/V Roger Revelle in the Tropical Western Pacific Ocean, 
September-October 2013,'' was prepared by LGL Ltd., Environmental 
Research Associates, on behalf of the National Science Foundation (NSF) 
and SIO. NMFS also issued a Biological Opinion under section 7 of the 
Endangered Species Act (ESA) to evaluate the effects of the survey and 
IHA on marine species listed as threatened and endangered. The NMFS 
Biological Opinion is available online at: http://www.nmfs.noaa.gov/pr/consultations/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, as amended (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 
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 adverse 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

[[Page 57355]]

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 5, 2013, NMFS received an application from the SIO 
requesting that NMFS issue an IHA for the take, by Level B harassment 
only, of small numbers of marine mammals incidental to conducting a 
low-energy marine seismic survey in International Waters (i.e., high 
seas) and in the Exclusive Economic Zone of the Federated States of 
Micronesia (Micronesia), the Independent State of Papua New Guinea 
(Papua New Guinea), the Republic of Indonesia (Indonesia), and the 
Republic of the Philippines (Philippines) during September to October 
2013. The SIO plans to use one source vessel, the R/V Roger Revelle 
(Revelle), and a seismic airgun array to collect seismic data in the 
tropical western Pacific Ocean. The SIO plans to use conventional low-
energy, seismic methodology to fill gaps in equatorial Pacific data 
sets, namely the lack of high-resolution records from the eastern part 
of the Western Pacific Warm Pool to better assess controls on the 
hydrologic cycle in the Western Pacific Warm Pool, and a limited 
meridional coverage to test hypotheses related to the Plio-Pleistocene 
evolution of the Western Pacific Warm Pool. In addition to the planned 
operations of the seismic airgun array and hydrophone streamer, SIO 
intends to operate a multi-beam echosounder and sub-bottom profiler 
continuously throughout the survey. On June 5, 2013, NMFS published a 
notice in the Federal Register (78 FR 33811) making preliminary 
determinations and proposing to issue an IHA. The notice initiated a 
30-day public comment period.
    Acoustic stimuli (i.e., increased underwater sound) generated 
during the operation of the seismic airgun array may have the potential 
to cause a 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 
26 species of marine mammals by Level B harassment. Take is not 
expected to result from the use of the multi-beam and sub-bottom 
profiler, for reasons discussed in this notice; nor is take expected to 
result from collision with the source vessel because it is a single 
vessel moving at a relatively slow speed 5 knots [kts]; 11.1 kilometers 
per hour [km/hr]; 6.9 miles per hour [mph]) during seismic acquisition 
within the survey, for a relatively short period of time (approximately 
26 operational days). It is likely that any marine mammal would be able 
to avoid the vessel.

Description of the Specified Activity

    SIO plans to conduct low-energy seismic and sediment coring surveys 
at 10 sites in the tropical western Pacific Ocean in September to 
October 2013. The study sites are located between approximately 4[deg] 
South to 8[deg] North and approximately 126.5 to 144.5[deg] East in 
international waters (i.e., high seas) and in the Exclusive Economic 
Zones (EEZ) of the Federated States of Micronesia (Micronesia), the 
Independent State of Papua New Guinea (Papua New Guinea), the Republic 
of Indonesia (Indonesia), and the Republic of the Philippines 
(Philippines) (see Figure 1 of the IHA application). Water depths in 
the survey area range from 450 to 3,000 meters (m) (1,476.4 to 9,842.5 
feet [ft]). The seismic surveys are scheduled to occur for 14 to 20 
hours at each of the 10 sites for approximately 26 operational days in 
September to October 2013. Some minor deviation from these dates would 
be possible, depending on logistics and weather.
    The surveys would fill gaps in equatorial Pacific data sets, namely 
the lack of high-resolution records from the eastern part of the 
Western Pacific Warm Pool to better assess the controls on the 
hydrologic cycle in the Western Pacific Warm Pool, and a limited 
meridional coverage to test hypotheses related to the Plio-Pleistocene 
evolution of the Western Pacific Warm Pool. To achieve the project's 
goals, the Principal Investigators, Drs. Y. Rosenthal and G. Mountain 
of Rutgers University propose to collect low-energy, high-resolution 
multi-channel seismic profiles and sediment cores in the heart of the 
Western Pacific Warm Pool. Survey data would also be included in a 
research proposal submitted to the Integrated Ocean Drilling Program 
(IODP) for funding consideration to extend the record of millennial 
climate variability in the western equatorial Pacific Ocean back to the 
mid-Miocene. Survey and site characterization data would assist the 
IODP in determining the viability of the sites for potential future 
drilling.
    The procedures to be used for the surveys would be similar to those 
used during previous seismic surveys by SIO and would use conventional 
seismic methodology. The survey will involve one source vessel, the R/V 
Roger Revelle. SIO will deploy two (each with a discharge volume of 45 
cubic inch [in\3\] with a total volume of 90 in\3\) Generator Injector 
(GI) airgun array as an energy source at a tow depth of 2 m (6.6 ft). 
The receiving system will consist of one 600 m (1,968.5 ft) long 
hydrophone streamer. As the GI airguns are towed along the survey 
lines, the hydrophone streamer will receive the returning acoustic 
signals and transfer the data to the onboard processing system.
    Straight survey lines will be collected in a grid of intersecting 
lines. Seven sites would be centered in small 9 x 9 km (4.9 x 4.9 nmi) 
grids of six intersecting lines (see Figure 1 of the IHA application). 
One site warrants slightly longer lines and would be surveyed in a 
large 18 x 18 km (9.7 x 9.7 nmi) grid of six intersection lines (see 
Figure 1 of the IHA application). Finally, sites S-1a and S-1b are 
close enough that efficiency in ship use would be achieved by covering 
both with a single grid of intersecting lines in a 30 x 26 km (16.2 x 
14 nmi). Individual survey lines in this grid would be approximately 5 
to 10 km (2.7 to 5.4 nmi) apart. The total track distance of survey 
data, including turns, would be approximately 1,033 km (557.8 nmi). 
Barring re-organization because of weather considerations or results 
that develop from data analyzed as sites are completed, sites would be 
surveyed in the order summarized in Table 1 (Table 1 of the IHA 
application). All planned seismic data acquisition activities will be 
conducted by technicians provided by SIO with onboard assistance by the 
scientists who have planned the study. The vessel will be self-
contained, and the crew will live aboard the vessel for the entire 
cruise.
    The planned seismic survey (e.g., equipment testing, startup, line 
changes, repeat coverage of any areas, and

[[Page 57356]]

equipment recovery) will consist of approximately 1,032.9 kilometer 
(km) (557.7 nautical miles [nmi]) of transect lines (including turns) 
in the survey area in the tropical western Pacific Ocean (see Figure 1 
of the IHA application). In addition to the operation of the airgun 
array, a multi-beam echosounder and a sub-bottom profiler will also 
likely be operated from the Revelle continuously throughout the cruise 
between the first and last survey sites. There will 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 SIO's estimated take calculations, 25% 
has been added for those additional operations.

Table 1--Survey Patterns and Lengths at Each Survey Site in the Tropical
         Western Pacific Ocean During September to October 2013
------------------------------------------------------------------------
          Survey site            Survey pattern (km)  Survey length (km)
------------------------------------------------------------------------
WP-5...........................  9 x 9 (4.9 x 4.9     82.2 (44.4 nmi).
                                  nmi).
WP-6...........................  9 x 9 (4.9 x 4.9     82.2 (44.4 nmi).
                                  nmi).
S-1a, S-1b.....................  30 x 26 (16.2 x 14)  349.5 (188.7).
WP-3...........................  9 x 9 (4.9 x 4.9     82.2 (44.4 nmi).
                                  nmi).
WP-4...........................  9 x 9 (4.9 x 4.9     82.2 (44.4 nmi).
                                  nmi).
WP-2...........................  9 x 9 (4.9 x 4.9     82.2 (44.4 nmi).
                                  nmi).
WP-1...........................  9 x 9 (4.9 x 4.9     82.2 (44.4 nmi).
                                  nmi).
WP-7...........................  9 x 9 (4.9 x 4.9     82.2 (44.4 nmi).
                                  nmi).
WP-8...........................  18 x 18 (9.7 x 9.7   108 (58.3 nmi).
                                  nmi).
                                                     -------------------
    Total......................  ...................  1,032.9 (557.7
                                                       nmi).
------------------------------------------------------------------------
\1\ Sites are listed in the intended order in which surveys would be
  conducted.

Dates, Duration, and Specified Geographic Region

    The planned project and survey sites are located between 
approximately 4[deg] South to 8[deg] North and approximately 126.5 to 
144.5[deg] East in International Waters and in the EEZs of Micronesia, 
Papua New Guinea, Indonesia, and the Philippines (see Figure 1 of the 
IHA application). Water depths in the survey area range from 
approximately 450 to 3,000 m (1,476.4 to 9,842.5 ft). The Revelle is 
expected to depart from Lae, Papua New Guinea on September 6, 2013 and 
arrive at Manila, Philippines on October 1, 2013 (see Table 1 of the 
IHA application for the order of survey sites). Seismic operations 
would take approximately 14 to 20 hours at each of the 10 sites, and 
total transit time to the first site, between all sites, and from the 
last site would be approximately 13 days. The remainder of the time, 
approximately 6 days, would be spent collecting sediment cores at the 
10 sites, for a total of 26 operational days. Some minor deviation from 
this schedule is possible, depending on logistics and weather (i.e., 
the cruise may depart earlier or be extended due to poor weather; there 
could be additional days of seismic operations if collected data are 
deemed to be of substandard quality).
    NMFS outlined the purpose of the program in a previous notice for 
the proposed IHA (78 FR 33811, June 5, 2013). 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 notice of the 
proposed IHA (78 FR 33811, June 5, 2013), the IHA application, EA, and 
associated documents referenced above this section.

Comments and Responses

    A notice of the proposed IHA for the SIO low-energy seismic survey 
was published in the Federal Register on June 5, 2013 (78 FR 33811). 
During the 30-day public comment period, NMFS received comments from 
the Marine Mammal Commission (Commission). The Commission's comments 
are online at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. 
Following are their substantive comments and NMFS's responses:
    Comment 1: The Commission recommends that NMFS require SIO, through 
the cooperation of the Lamont-Doherty Earth Observatory of Columbia 
University (L-DEO) and the National Science Foundation (NSF), to 
determine whether the range of sound speeds (minimums to maximums) at 
each of the 10 survey sites would increase the associated radii by 20 
percent or more and if so, require SIO to re-estimate the proposed 
exclusion and buffer zones and associated takes of marine mammals 
accordingly.
    Response: For clarification, it is not claimed that the model 
provides exact predictions of received sound levels, instead, the L-DEO 
model results are used to inform distances for the radii of exclusion 
zones established for mitigation purposes in a way that comparison with 
actual data has shown to be generally conservative.
    The L-DEO model used for deep water is based on spherical spreading 
in a constant-velocity medium (where sound level decreases as a 
function of distance from the source) and incorporates the free surface 
reflection at the water-air interface. L-DEO has estimated that if for 
a given source configuration the constant sound speed input to the 
model changes between 1,475 m/second (4,839.2 ft/second) and 1,545 m/
second (5,068.9 ft/second) (a 70 m/second [229.7 ft/second] 
difference), the corresponding change in exclusion zone radii for 
mitigation would be on the order of 2%. Based on the results of this 
sensitivity test, and given that the impact of such 2% variation on the 
take estimates would be very small, using a single sound speed value, 
such as 1,521.6 m/second (4,992.1 ft/second), for all model runs is 
appropriate.
    The following statement ``Diebold et al. (2010) demonstrated that 
L-DEO's model underestimates the near-field sound level in waters of 
intermediate depth (600 to 1,100 m [1,968.5 to 3,608.9 ft])'' is 
incorrect. In intermediate water depth, a correction factor of 1.5 is 
applied to the deep-water model results. After application of this 
correction factor, calibration measurements fall below the model curve 
adapted to intermediate water depth environments. This process and 
revised model curve is not described in Diebold et al. (2010) but was 
defined in numerous IHA applications and presented and further 
explained at a recent meeting with staff from the Commission, NMFS, 
NSF, and L-DEO. Furthermore, the

[[Page 57357]]

``underestimate'' associated with ``. . . the far-field sound level in 
waters of deep depth (1,600 to 1,700 m [5,249.3 to 5,577.4 ft])'' 
refers to, at most, 10 data points (out of a thousand for more) with 
SEL less than 150 dB (Figure 11 in Diebold et al., 2010), and may be 
perhaps associated with the effect of local topographic features, which 
would be challenging for any model to accurately predict. In other 
words, what can be conservatively described as an underestimate of the 
sound level in the far-field (in this particular case) is referring to 
only a very small fraction of the measurements. Based on the 
explanations already provided, NMFS is satisfied that the applicants 
have provided sufficient scientific justification for their take 
estimates.
    Comment 2: The Commission recommends that NMFS require L-DEO and 
NSF to test the accuracy of L-DEO's model by comparing it to the 
hydrophone data collected during previous surveys from environments 
other than the Gulf of Mexico (GOM) prior to the submittal of 
applications for the NMFS for seismic surveys to be conducted in 2014--
if the L-DEO and NSF either do not have enough data to compare the L-
DEO's model to other environments or do not assess the accuracy of the 
model, re-estimate the proposed exclusion and buffer zones and 
associated takes of marine mammals using site-specific parameters 
(including sound speed profiles, bathymetry, and bottom 
characteristics) for all future applications that use the L-DEO's 
model.
    Response: NMFS evaluates the reasonableness of take estimates based 
on the best and latest scientific information available to NMFS at the 
time of the request. Nonetheless, NSF and L-DEO are proactively 
investigating novel ways to further verify the accuracy of model 
results in different geographic regions, including potentially cross-
checking model results to hydrophone data collected during previous 
surveys, within the constraints of the currently limited federal 
budgetary environment.
    Comment 3: The Commission recommends that NMFS (1) require SIO to 
revise its take estimates to include Level B harassment takes 
associated with the use of sub-bottom profiler and multi-beam 
echosounder when the airgun array is not firing; and (2) follow a 
consistent approach of requiring the assessment of Level B harassment 
takes for those types of sound sources (e.g., sub-bottom profilers, 
echosounders, side-scan sonar, and fish-finding sonar) by all 
applicants, who propose to use such sources.
    Response: As described in NSF's application and the NSF/USGS PEIS 
(2011), they expect the sound levels produced by the sub-bottom and 
multi-beam echosounder sound sources to be exceeded by the sound levels 
produced by the airguns for the majority of the time. Additionally, 
because of the beam pattern and directionality of these sources, 
combined with their lower source levels, it is far less likely that 
these sources (which are used in some capacity by the vast majority of 
vessels on the water) will take marine mammals independently from the 
takes that have already been estimated for the airguns. Therefore, NMFS 
does not believe it is necessary to authorize additional takes for 
these sources for this action. Nonetheless, NMFS is currently 
evaluating the broader use of these types of sources to determine under 
what specific circumstances coverage for incidental take would be 
advisable (or not) and is working on guidance that would outline a 
consistent recommended approach (to be used by applicants and NMFS) for 
addressing the potential impacts of these types of sources.
    Comment 4: The Commission recommends that NMFS require SIO to 
estimate the number of marine mammals taken when the sub-bottom 
profiler and multi-beam echosounder are used in the absence of the 
airgun array based on the 120 dB (rms) threshold rather than the 160 dB 
(rms) threshold.
    Response: NMFS disagrees with the Commission's recommendation that 
NMFS require SIO to estimate the number of marine mammals taken when 
the sub-bottom profiler and multi-beam echosounder are used in absence 
of the airgun array based on the 120 dB (rms) threshold rather than the 
160 dB (rms) threshold. 160 dB (rms) is the appropriate threshold for 
these sound sources. Continuous sounds are those whose sound pressure 
level remains above that of the ambient sound, with negligibly small 
fluctuations in level (NIOSH, 1998; ANSI, 2005), while intermittent 
sounds are defined as sounds with interrupted levels of low or no sound 
(NIOSH, 1998). Thus, echosounder signals are not continuous sounds but 
rather intermittent sounds. Intermittent sounds can further be defined 
as either impulsive or non-impulsive. Impulsive sounds have been 
defined as sounds which are typically transient, brief (less than 1 
second), broadband, and consist of a high peak pressure with rapid rise 
time and rapid decay (ANSI, 1986; NIOSH, 1998). Echosounder signals 
also have durations that are typically very brief (less than 1 second), 
with temporal characteristics that more closely resemble those of 
impulsive sounds than non-impulsive sounds, which typically have more 
gradual rise times and longer decays (ANSI, 1995; NIOSH, 1998). With 
regard to behavioral thresholds, we therefore consider the temporal and 
spectral characteristics of echosounder signals to more closely 
resemble those of an impulse sound than a continuous sound.
    The Commission suggests that, for certain sources considered here, 
the interval between pulses would not be discernible to the animal, 
thus rendering them effectively continuous. However, an echosounder's 
``rapid staccato'' of pulse trains is emitted in a similar fashion as 
odontocete echolocation click trains. Research indicates that marine 
mammals, in general, have extremely fine auditory temporal resolution 
and can detect each signal separately (e.g., Au et al., 1988; Dolphin 
et al., 1995; Supin and Popov, 1995; Mooney et al., 2009), especially 
for species with echolocation capabilities. Therefore, it is highly 
unlikely that marine mammals would perceive echosounder signals as 
being continuous.
    In conclusion, echosounder signals are intermittent rather than 
continuous signals, and the fine temporal resolution of the marine 
mammal auditory system allows them to perceive these sounds as such. 
Further, the physical characteristics of these signals indicate a 
greater similarity to the way that intermittent, impulsive sounds are 
received. Therefore, the 160 dB threshold (typically associated with 
impulsive sources) is more appropriate than the 120 dB threshold 
(typically associated with continuous sources) for estimating takes by 
behavioral harassment incidental to use of such sources.
    Comment 5: The Commission recommends that NMFS consult with experts 
in the field of sound propagation and marine mammal hearing to revise 
the acoustic criteria and thresholds as necessary to specify threshold 
levels that would be more appropriate criteria and thresholds as 
necessary to specify threshold levels that would be more appropriate 
for a wider range of sound sources, including sub-bottom profilers and 
echosounders.
    Response: NMFS agrees with the Commission's recommendation to 
revise existing acoustic criteria and thresholds as necessary to 
specify threshold levels that would be more appropriate for a wider 
range of sound sources, and are currently in process of producing such 
revisions. In particular, NMFS

[[Page 57358]]

recognizes the importance of context (e.g., behavioral state of the 
animals, distance) in behavioral responses. The current behavioral 
categorization (i.e., impulse vs. continuous) does not account for 
context and is not appropriate for all sound sources. Thus, updated 
NOAA Acoustic Guidance (http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm) will more appropriately categorize behavioral 
harassment criteria by activity type.
    Comment 6: The Commission recommends that NMFS require SIO to use 
the (1) original density estimates from Dolar et al. (2006) rather than 
the estimates that have been adjusted by an arbitrary correction factor 
of 0.5; (2) density estimates for Fraser's dolphins from the Sulu Sea 
in 1994 and 1995 rather than just 1995; and (3) adjust density 
estimates for all species using some measure of uncertainty (e.g., two 
standard deviations) and re-estimate the numbers of takes accordingly.
    Response: Based on the Commission's recommendation, NMFS has used 
the original density estimates from Dolar et al. (2006) without the 
adjusted correction factor of 0.5 for several marine mammals species 
(i.e., spinner, pantropical, Fraser's, bottlenose, and Risso's 
dolphins, and short-finned pilot, melon-headed, and dwarf sperm whales) 
and has recalculated the estimated possible number of individuals that 
may be exposed to sound levels greater than or equal to 160 dB (rms) 
during SIO's low-energy seismic survey, see Table 4 (below).
    For estimating takes of Fraser's dolphins, NMFS has used the 
original density estimates from Dolar et al. (2006) without the 
adjusted correction factor of 0.5 (i.e., 430 animals/1,000 km\2\) and 
the density estimates for Fraser's dolphins from the Sulu Sea in 1994 
(i.e., 730 animals/1,000 km\2\) and 1995 (i.e., 430 animals/1,000 
km\2\). The combined density for 1994 and 1995 is 580 animals/1,000 
km\2\. NMFS applied this combined density based on the Commission's 
recommendation. Using SIO's approach for calculating take of Fraser's 
dolphins, the number of different individuals potentially exposed to 
received levels greater than or equal to 160 re 1 [micro]Pa (rms) was 
determined by multiplying the expected species density (i.e., 580 
animals/1,000 km\2\), times the anticipated area to be ensonified to 
that level during airgun operations excluding overlap (i.e., 1,063.8 
km\2\ including 25% contingency), which is approximately 617 animals.
    Regarding the Commission's recommendation to adjust density 
estimates for all marine mammal species using some measure of 
uncertainty (e.g., two standard deviations) and re-estimate the number 
of takes, please see the response to Comment 7 (below).
    Comment 7: The Commission recommends that NMFS formulate policy or 
guidance regarding a consistent approach for how applicants should 
incorporate uncertainty in density estimates.
    Response: The availability of representative density information 
for marine mammal species varies widely across space and time. 
Depending on where surveys and modeling have been conducted, it may be 
necessary to consult estimates that are from a different area or 
season, that are at a non-ideal spatial scale, or that have not been 
updated in several years. NMFS is currently evaluating available 
density information and is working on guidance that would outline a 
consistent approach for addressing uncertainty in specific situations 
where certain types of data are or are not available.
    Comment 8: The Commission recommends that NMFS consult with the 
funding agency (i.e., NSF) and individual applicants (e.g., SIO and L-
DEO) to develop, validate, and implement a monitoring program that 
provides a scientifically sound, reasonably accurate assessment of the 
types of marine mammal takes and the actual numbers of marine mammals 
taken--the assessment should account for applicable g(0) and f(0) 
values.
    Response: There will be periods of transit time during the cruise, 
and PSOs will be on watch prior to and after the seismic portions of 
the surveys, in addition to during the surveys. The collection of this 
visual observational data by PSOs may contribute to baseline data on 
marine mammals (presence/absence) and provide some generalized support 
for estimated take numbers, but is unlikely that the information 
gathered from these cruises along would result in any statistically 
robust conclusions for any particular species because of the small 
number of animals typically observed.
    NMFS is currently working to develop recommendations for how 
applicants can appropriately correct marine mammal detections to better 
estimate the number of animals likely taken during specified 
activities, in consideration of those that are not detected.
    Comment 9: The Commission recommends that NMFS work with NSF to 
analyze monitoring data to assess the effectiveness of ramp-up 
procedures as a mitigation measure for seismic surveys.
    Response: NMFS acknowledges the Commission's request for an 
analysis of ramp-ups and will work with NSF and SIO to help identify 
the effectiveness of the mitigation measure for seismic surveys. The 
IHA requires that PSOs on the Revelle make observations for 30 minutes 
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.
    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 requires NSF and SIO to 
gather all data that could potentially provide information regarding 
the effectiveness of ramp-up as a mitigation measure in its monitoring 
report. However, considering the low numbers of marine mammal sightings 
and low number 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 PSOs detect animals during ramp-up.
    Comment 10: An individual opposes the issuance of the IHA to SIO, 
SIO's project is killing marine mammals.
    Response: As described in detail in the Federal Register notice for 
the proposed IHA (78 FR 33811, June 5, 2013), as well as in this 
document, NMFS does not believe that SIO's low energy seismic survey 
would cause injury, serious injury, or mortality to marine mammals, nor 
are those authorized under the IHA. The required monitoring and 
mitigation measures that SIO would implement during the low-energy 
seismic survey would further reduce the adverse effect on marine 
mammals to the lowest levels

[[Page 57359]]

practicable. NMFS anticipates only behavioral disturbance to occur 
during the conduct of the low-energy seismic survey. Description of the 
Marine Mammals in the Specified Geographic Area of the Specified 
Activity
    The marine mammal species that potentially occur within the 
tropical western Pacific Ocean include 26 species of cetaceans and one 
sirenian. In addition to the 26 species known to occur in the tropical 
western Pacific Ocean, there are three species known to occur in 
coastal waters of the study area, these include the Australian snubfin 
dolphin (Orcaella heinsohni), Indo-Pacific humpback dolphin (Sousa 
chinensis), and the Indo-Pacific bottlenose dolphin (Tursiops aduncus). 
However, these species do not occur in in slope or deep, offshore 
waters where the planned activities would take place. Those three 
species are not considered further in this document. No pinnipeds are 
known to occur in the study area.
    The marine mammals that generally occur in the action area belong 
to three taxonomic groups: Mysticetes (baleen whales), odontocetes 
(toothed whales), and sirenians (the dugong). Marine mammal species 
listed as endangered under the U.S. Endangered Species Act of 1973 
(ESA; 16 U.S.C. 1531 et seq.), includes the humpback (Megaptera 
novaeangliae), sei (Balaenoptera borealis), fin (Balaenoptera 
physalus), blue (Balaenoptera musculus), and sperm (Physeter 
macrocephalus) whale, as well as the dugong. Of those endangered 
species, the humpback, sei, fin, blue, and sperm whale is likely to be 
encountered in the survey area. The dugong (Dugong dugon) is the one 
marine mammal species mentioned in this document that 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.
    Few systematic surveys have been conducted in the tropical western 
Pacific Ocean, and none have taken place during September to October. 
Borsa and Nugroho (2010) conducted 1,561 km (842.9 nmi) of surveys of 
Raja Ampat waters, including the Halmahera Sea, in West Papua during 
November to December 2007. Visser (2002 in Visser and Bonoccorso, 2003) 
conducted preliminary surveys in Kimbe Bay, New Britain, Papua New 
Guinea. Miyazaki and Wada (1978) surveyed 11,249 km (6,074 nmi) in the 
wider tropical Pacific, including Micronesia, and the waters off Papua 
New Guinea and the Solomon Islands during January to March 1976. 
Shimada and Miyashita (2001) conducted 8,721 km (4,709 nmi) of surveys 
in Micronesia, the Solomon Islands, and north of Papua New Guinea 
during February to March from 1999 to 2001. Oremus (2011) described 
4,523 km (2,442.2 nmi) of surveys in the Solomon Islands during 
November of 2009 and 2010. Dolar et al. (2006) surveyed the waters of 
the central Philippines, including the Sulu Sea, during May to June 
1994 and 1995; 2,747 km (1,483.3 nmi) were covered. In May 1996, Dolar 
et al. (1997) surveyed 825 km (445.5 nmi) in the southern Sulu Sea. 
Another survey of relevance to the survey area is one that took place 
during January to April 2007 in the waters of Guam and the Commonwealth 
of the Northern Mariana Islands; a total of 11,033 km (5,957.3 nmi) 
were surveyed in the area 10 to 18[deg] North and 142 to 148[deg] East 
(SRS-Parsons, 2007; Fulling et al., 2011). The aforementioned surveys 
took place in shallow coastal waters as well as deeper offshore waters. 
Records from the Ocean Biogeographic Information System (OBIS) database 
hosted by Rutgers and Duke University (Read et al., 2009) were also 
considered. Table 3 (below) presents information on the abundance, 
distribution, population status, conservation status, and population 
trend of the species of marine mammals that may occur in the study area 
during September to October 2013.

  Table 2--The Habitat, Regional Abundance, and Conservation Status of Marine Mammals That May Occur in or Near
                    the Low-Energy Seismic Survey Area in the Tropical Western Pacific Ocean
                         [See text and Table 3 in SIO's application for further details]
----------------------------------------------------------------------------------------------------------------
                                                                Population
               Species                        Habitat            estimate          ESA \1\          MMPA \2\
----------------------------------------------------------------------------------------------------------------
Mysticetes:
    Humpback whale (Megaptera         Pelagic, nearshore           \3\ 3,520  EN                D
     novaeangliae).                    waters, and banks.
    Minke whale (Balaenoptera         Pelagic and coastal...      \4\ 25,000  NL                NC
     acutorostrata).
    Bryde's whale (Balaenoptera       Pelagic and coastal...      \5\ 21,000  NL                NC
     edeni).
    Omura's whale (Balaenoptera       Pelagic and coastal...              NA  NL                NC
     omurai).
    Sei whale (Balaenoptera           Primarily offshore,          \6\ 7,260  EN                D
     borealis).                        pelagic.                    to 12,620
    Fin whale (Balaenoptera           Continental slope,          \7\ 13,620  EN                D
     physalus).                        pelagic.                    to 18,680
    Blue whale (Balaenoptera          Pelagic, shelf,                     NA  EN                D
     musculus).                        coastal.
Odontocetes:
    Sperm whale (Physeter             Pelagic, deep sea.....      \8\ 29,674  EN                D
     macrocephalus).
    Pygmy sperm whale (Kogia          Deep waters off the                 NA  NL                NC
     breviceps).                       shelf.
    Dwarf sperm whale (Kogia sima)..  Deep waters off the         \9\ 11,200  NL                NC
                                       shelf.
    Cuvier's beaked whale (Ziphius    Pelagic...............      \9\ 20,000  NL                NC
     cavirostris).
    Longman's beaked whale            Pelagic...............              NA  NL                NC
     (Indopacetus pacificus).
    Ginkgo-toothed beaked whale       Pelagic...............     \10\ 25,300  NL                NC
     (Mesoplodon ginkgodens).
    Blainville's beaked whale         Pelagic...............     \10\ 25,300  NL                NC
     (Mesoplodon densirostris).
    Killer whale (Orcinus orca).....  Pelagic, shelf,              \9\ 8,500  NL                NC
                                       coastal.
    Short-finned pilot whale          Pelagic, shelf coastal     \12\ 53,608  NL                NC
     (Globicephala macrorhynchus).
    False killer whale (Pseudorca     Pelagic...............     \12\ 16,668  NL                NC
     crassidens).
    Melon-headed whale                Pelagic...............      \9\ 45,400  NL                NC
     (Peponocephala electra).
    Pygmy killer whale (Feresa        Pelagic...............      \9\ 38,900  NL                NC
     attenuata).
    Risso's dolphin (Grampus          Deep water, seamounts.     \12\ 83,289  NL                NC
     griseus).
    Bottlenose dolphin (Tursiops      Offshore, inshore,        \12\ 168,792  NL                NC
     truncatus).                       coastal, estuaries.
    Rough-toothed dolphin (Steno      Pelagic...............    \11\ 107,633  NL                NC
     bredanensis).
    Fraser's dolphin (Lagenodelphis   Pelagic...............     \9\ 289,300  NL                NC
     hosei).
    Striped dolphin (Stenella         Pelagic...............    \13\ 570,038  NL                NC
     coeruleoalba).
    Pantropical spotted dolphin       Coastal, pelagic......    \11\ 438,064  NL                NC
     (Stenella attenuata).

[[Page 57360]]

 
    Spinner dolphin (Stenella         Coastal, pelagic......    \13\ 734,837  NL                NC
     longirostris).
Sirenians:
    Dugong (Dugong dugon)...........  Coastal...............              NA  EN                D
----------------------------------------------------------------------------------------------------------------
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\ Oceania (Constantine et al., 2010).
\4\ Northwest Pacific and Okhotsk Sea (IWC, 2013).
\5\ Western North Pacific (IWC, 2013).
\6\ North Pacific (Tillman, 1977).
\7\ North Pacific (Ohsumi and Wada, 1974).
\8\ Western North Pacific (Whitehead, 2002).
\9\ Eastern Tropical Pacific (Wade and Gerrodette, 1993).
\10\ Eastern Tropical Pacific, all Mesoplodon spp. (Wade and Gerrodette, 1993)
\11\ Eastern Tropical Pacific (Gerrodette et al., 2008).
\12\ Western North Pacific (Miyashita, 1993).
\13\ Whitebelly stock in Eastern Tropical Pacific (Gerrodette et al., 2008).

    Refer to sections 3 and 4 of SIO's 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 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 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).
    The notice of the proposed IHA (78 FR 33811, June 5, 2013) included 
a discussion of the effects of sounds from airguns on mysticetes and 
odontocetes 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, 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 (78 FR 33811, June 5, 2013). The seismic 
survey will not result in any permanent impact on habitats used by the 
marine mammals in the survey area, including the food sources they use 
(i.e., fish and invertebrates), and there will be no physical damage to 
any habitat. 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 was considered in further detail in this notice of the proposed 
IHA (78 FR 33811, June 5, 2013), as behavioral modification. The main 
impact associated with the activity will be temporarily elevated noise 
levels and the associated direct effects on marine mammals.

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 adverse 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.
    SIO 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 recently 
completed NSF/USGS PEIS (2011);
    (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 have planned 
to implement the following mitigation measures for marine mammals:
    (1) Exclusion zones around the sound source;
    (2) Speed and course alterations;
    (3) Shut-down procedures; and
    (4) Ramp-up procedures.

[[Page 57361]]

    Exclusion Zones--SIO use radii to designate exclusion and buffer 
zones and to estimate take for marine mammals. Table 3 (see below) 
shows the distances at which one would expect to receive three sound 
levels (160 and 180 dB) from the two GI airgun array. The 180 dB level 
shut-down criteria are applicable to cetaceans, as specified by NMFS 
(2000). SIO 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 180 and 160 dB re 1 [micro]Pa (rms) in deep water were determined 
(see Table 3 below).
    Empirical data concerning the 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 planned 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 plans to use the safety radii 
predicted by L-DEO's model for the planned GI airgun operations in deep 
water, although they are likely conservative given the empirical 
results for the other arrays. The 180 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 dB radii are 100 m for intermediate 
and deep water, respectively. If the PSO detects a marine mammal(s) 
within or about to enter the appropriate exclusion zone, the airguns 
will be shut-down immediately.
    Table 3 summarizes the predicted distances at which sound levels 
(160 and 180 dB [rms]) are expected to be received from the two airgun 
array operating in intermediate (100 to 1,000 m [328 to 3,280 ft]) and 
deep water (greater than 1,000 m [3,280 ft]) depths.

 Table 3--Predicted and Modeled (Two 45 in\3\ GI Airgun Array) Distances to Which Sound Levels >= 180 and 160 dB
re: 1 [mu]Pa (rms) Could Be Received in Intermediate and Deep Water During the Low-Energy Survey in the Tropical
                                Western Pacific Ocean, September to October 2013
----------------------------------------------------------------------------------------------------------------
                                                                   Predicted RMS radii distances (m) for 2 GI
                                                                                  airgun array
   Source and total volume      Tow depth (m)  Water depth (m) -------------------------------------------------
                                                                         160 dB                   180 dB
----------------------------------------------------------------------------------------------------------------
Two GI Airguns (90 in\3\)....               2  Intermediate     600 (1,968.5 ft).......  100 (328 ft).
                                                (100 to 1,000).
Two GI Airguns (90 in\3\)....               2  Deep (> 1,000).  400 (1,312.3 ft).......  100 (328 ft).
----------------------------------------------------------------------------------------------------------------

    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 will be considered 
if this does not compromise operational safety. This would be done if 
operationally practicable while minimizing the effect on the planned 
science objectives. For marine seismic surveys towing large streamer 
arrays, however, course alterations are not typically implemented due 
to the vessel's limited maneuverability. After any such speed and/or 
course alteration is begun, the marine mammal activities and movements 
relative to the seismic vessel will 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 will be taken, including further 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 will need to be 
implemented.
    Shut-down Procedures--SIO will shut-down the operating airgun(s) if 
a marine mammal is detected outside the exclusion zone for the 
airgun(s), and if the vessel's speed and/or course cannot be changed to 
avoid having the animal enter the exclusion zone, the seismic source 
will be shut-down 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 will be shut down immediately.
    Following a shut-down, SIO will not resume airgun activity until 
the marine mammal has cleared the exclusion zone. SIO will 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), 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 going 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)--but 
probably not 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. 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 shut down has exceeded that 
period. SIO proposes that, for the

[[Page 57362]]

present cruise, this period would be approximately 15 minutes. L-DEO 
and USGS has used similar periods (approximately 15 minutes) during 
previous low-energy seismic surveys.
    Ramp-up will begin with a single GI airgun (45 in\3\). The second 
GI airgun (45 in\3\) will be added after 5 minutes. During ramp-up, the 
PSOs will monitor the exclusion zone, and if marine mammals are 
sighted, a shut-down will 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, SIO will not commence the ramp-up. Given these provisions, 
it is likely that the airgun array will 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 will not be visible during those 
conditions. If one airgun has operated, ramp-up to full power will be 
permissible at night or in poor visibility, on the assumption that 
marine mammals will 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. SIO will 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.
    NMFS has carefully evaluated the applicant's 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 
adverse 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.
    Based on NMFS's evaluation of the applicant's measures, as well as 
other measures considered by NMFS or recommended by the public, NMFS 
has determined that the mitigation measures provide the means of 
effecting the least practicable adverse impacts on marine mammal 
species or stocks and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance.

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 action area.

Monitoring

    SIO will conduct marine mammal monitoring during the project, in 
order to implement the mitigation measures that require real-time 
monitoring, and to satisfy the anticipated monitoring requirements of 
the IHA. SIO's ``Monitoring Plan'' is described below this section. SIO 
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. SIO 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

    SIO's PSOs will be based aboard the seismic source vessel and will 
watch for marine mammals near the vessel during daytime airgun 
operations and during any ramp-ups of the airguns at night. PSOs will 
also watch for marine mammals near the seismic vessel for at least 30 
minutes prior to the start of airgun operations after an extended shut-
down (i.e., greater than approximately 15 minutes for this cruise). 
When feasible, PSOs will conduct observations during daytime periods 
when the seismic system is not operating for comparison of sighting 
rates and behavior with and without airgun operations and between 
acquisition periods. Based on PSO observations, the airguns will 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 tropical western Pacific Ocean, at 
least three PSOs will be based aboard the Revelle. SIO will appoint the 
PSOs with NMFS's concurrence. Observations will take place during 
ongoing daytime operations and nighttime ramp-ups of the airguns. 
During the majority of seismic operations, at least one PSO will be on 
duty from observation platforms (i.e., the best available vantage point 
on the source vessel) to monitor marine mammals near the seismic 
vessel. PSO(s) will be on duty in shifts no longer than 4 hours in 
duration. Other crew will also be instructed to assist in detecting 
marine mammals and implementing mitigation requirements (if practical). 
Before the start of the seismic survey, the crew will be given 
additional instruction on how to do so.
    The Revelle is a suitable platform for marine mammal observations 
and will serve as the platform from which PSOs will watch for marine 
mammals before and during seismic operations. The Revelle has been used 
for that purpose during the routine California Cooperative Oceanic 
Fisheries Investigations (CalCOFI). Two locations are likely as 
observation stations onboard the Revelle. Observing stations are 
located on the 02 level, with the PSO eye level at approximately 10.4 m 
(34.1 ft) above the waterline. At a forwarded-centered position on the 
02 deck, the view is approximately 240[deg]; an aft-centered view 
includes the 100 m (328.1 ft) radius area around the GI airguns. The 
PSO eye level on the bridge is approximately 15 m (49.2 ft) above sea 
level. Standard equipment for PSOs will be reticule binoculars and 
optical range finders. At night, night-vision equipment will be 
available. The PSOs will 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. Observing stations will be at the 02 level with PSO's 
eye level approximately 10.4 m (34 ft) above sea level--one forward on 
the 02 deck commanding a forward-centered, approximately 240[deg] view 
around the vessel, and one atop the aft hangar, with an aft-centered 
view that includes the radii around the airguns. The eyes on the bridge 
watch will be at a height of approximately 15 m (49 ft); PSOs will work 
on the enclosed bridge and adjoining aft steering station during any 
inclement weather. During daytime, the PSO(s) will scan the area around 
the vessel systematically with reticle binoculars (e.g., 7 x 50 
Fujinon), Big-eye binoculars (e.g., 25 x 150), optical range-

[[Page 57363]]

finders (to assist with distance estimation), and the naked eye. At 
night, night-vision equipment will be available. The optical range-
finders are useful in training observers to estimate distances 
visually, but are generally not useful in measuring distances to 
animals directly. Estimating distances is done primarily with the 
reticles in the binoculars. The PSO(s) will be in wireless 
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 a shut-down of the seismic source.
    When marine mammals are detected within or about to enter the 
designated exclusion zone, the airguns will immediately be shut-down if 
necessary. The PSO(s) will continue to maintain watch to determine when 
the animal(s) are outside the exclusion zone by visual confirmation. 
Airgun operations will not resume until the animal is confirmed to have 
left the exclusion zone, or if not observed after 15 minutes for 
species with shorter dive durations (small odontocetes) or 30 minutes 
for species with longer dive durations (mysticetes and large 
odontocetes, including sperm, pygmy sperm, dwarf sperm, killer, and 
beaked whales).

PSO Data and Documentation

    PSOs will 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 will be used to estimate 
numbers of animals potentially ``taken'' by harassment (as defined in 
the MMPA). They will also provide information needed to order a shut-
down of the airguns when a marine mammal is within or near the 
exclusion zone. Observations will also be made during daytime periods 
when the Revelle 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 will 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) will 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 will be recorded in a standardized format. Data will be 
entered into an electronic database. The data accuracy will 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 will allow initial summaries of data to be prepared during 
and shortly after the field program, and will facilitate transfer of 
the data to statistical, graphical, and other programs for further 
processing and archiving.
    Results from the vessel-based observations will 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.
    SIO will submit a comprehensive report to NMFS within 90 days after 
the end of the cruise. The report will describe the operations that 
were conducted and sightings of marine mammals near the operations. The 
report submitted to NMFS will provide full documentation of methods, 
results, and interpretation pertaining to all monitoring. The 90-day 
report will 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 will minimally 
include:
     Summaries of monitoring effort--total hours, total 
distances, and distribution of marine mammals through the study period 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals;
     Analyses of the effects of various factors influencing 
detectability of marine mammals including 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 will also include estimates of the number and nature of 
exposures that could result in ``takes'' of marine mammals by 
harassment or in other ways. After the report is considered final, it 
will 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), SIO will 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], and the NMFS 
Pacific Islands Region Marine Mammal Stranding and Entanglement Hotline 
at 1-888-256-9840 ([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.

[[Page 57364]]

NMFS shall work with SIO to determine what is necessary to minimize the 
likelihood of further prohibited take and ensure MMPA compliance. SIO 
may not resume their activities until notified by NMFS via letter or 
email, or telephone.
    In the event that SIO discovers an injured or dead marine mammal, 
and the lead PSO determines that the cause of the injury or death is 
unknown and the death is relatively recent (i.e., in less than a 
moderate state of decomposition as described in the next paragraph), 
SIO will 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], and the NMFS Pacific Islands Region Marine 
Mammal Stranding and Entanglement Hotline (1-888-256-9840) and/or by 
email to the Pacific Islands Regional Stranding Coordinator 
([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 will work 
with SIO to determine whether modifications in the activities are 
appropriate.
    In the event that SIO discovers an injured or dead marine mammal, 
and the lead PSO determines that the injury or death is not associated 
with or related to the activities authorized in the IHA (e.g., 
previously wounded animal, carcass with moderate or advanced 
decomposition, or scavenger damage), SIO will 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], and the NMFS 
Pacific Islands Regional Marine Mammal Stranding and Entanglement 
Hotline (1-888-256-9840), and/or by email to the Pacific Islands 
Regional Stranding Coordinator ([email protected]), within 24 
hours of discovery. SIO will provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network. 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].
    Level B harassment is anticipated and authorized as a result of the 
low-energy marine seismic survey in the tropical western Pacific 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 could result in injury, serious injury, or 
mortality for which SIO seeks the IHA. The required mitigation and 
monitoring measures will minimize any potential risk for injury, 
serious injury, or mortality.
    The following sections describe SIO'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 planned 
seismic program in the tropical western Pacific Ocean. The estimates 
are based on a consideration of the number of marine mammals that could 
be harassed by approximately 1,033 km (557.8 nmi) of seismic operations 
with the two GI airgun array to be used as depicted in Figure 1 of the 
IHA application.
    During simultaneous operations of the airgun array and the other 
sources, any marine mammals close enough to be affected by the multi-
beam echosounder and sub-bottom profiler would already be affected by 
the airguns. During times when the airguns are not operating, it is 
unlikely that marine mammals will exhibit more than minor, short-term 
responses to the multi-beam echosounder and sub-bottom profiler given 
their characteristics (e.g., narrow, downward-directed beam) and other 
considerations described previously in our notice of the proposed IHA 
(78 FR 33811, June 5, 2013). Therefore, take was not authorized 
specifically for these sound sources beyond that which is already 
authorized for airguns.
    The only densities reported for the overall survey area are for 
eight species sighted during vessel-based surveys in coastal and 
oceanic waters of the Sulu Sea, Philippines, covering an area of 
approximately 23,000 km\2\ (6,705.7 nmi\2\), during May to June 1994 
and 1995 (Dolar et al., 2006). To supplement those density data, SIO 
used densities for seven other species expected to occur in the survey 
area that were sighted during a systematic vessel-based marine mammal 
survey in Guam and the southern Commonwealth of the Northern Mariana 
Islands (CNMI) during January to April 2007 (Fulling et al., 2011). The 
cruise area was defined by the boundaries 10 to 18[deg] North and 142 
to 148[deg] East, encompassing an area of approximately 585,000 km\2\ 
(170,558.7 nmi\2\). For five species not sighted in either survey, but 
expected to occur in the planned survey area, SIO also used densities 
for the ``outer EEZ stratum'' of Hawaiian waters, covering 
approximately 2,240,000 km\2\ (653,079.5 nmi\2\), based on a survey 
conducted in August to November 2002 (Barlow, 2006). All three surveys 
used standard line-transect protocols developed by NMFS Southwest 
Fisheries Science Center. Survey effort was 2,313 km (1,248.9 nmi) in 
the Sulu Sea, 11,033 km (5,957.3 nmi) in the CNMI, and 13,500 km 
(7,289.4 nmi) in Hawaii.
    The densities mentioned above have been corrected, by the original 
authors, for trackline detection probability bias, and in one of the 
three areas, for availability bias. Trackline detection probability 
bias is associated with diminishing sightability with increasing 
lateral distance from the trackline f(0). Availability bias refers to 
the fact that there is less than 100% probability of sighting an animal 
that is present along the survey trackline, and it is measured by g(0). 
Dolar et al. (2006) and Fulling et al. (2011) did not correct the CNMI 
densities for g(0), which for all but large (greater than 20) groups of 
dolphins (where g(0) = 1), resulted in underestimates of density. 
Although there is some uncertainty about the representatives of the 
data and the assumptions used in the calculations below, the approach 
used here is believed to be the best available approach.

[[Page 57365]]



 Table 4--Estimated Densities and Possible Number of Marine Mammal Species That Might Be Exposed To Greater Than
    or Equal to 160 dB During SIO's Low-Energy Seismic Survey (Ensonified Area 1,063.8 km\2\) in the Tropical
                                Western Pacific Ocean, September to October 2013
----------------------------------------------------------------------------------------------------------------
                                                          Calculated take
                                                          (i.e., estimated     Approximate
                                      Density  (/1,000 km\2\)      individuals      best population     Requested take
                                             \1\          exposed to sound  estimate of stock  authorization \4\
                                                          levels >= 160 dB  (calculated take)
                                                          re 1 [mu]Pa) \2\         \3\
----------------------------------------------------------------------------------------------------------------
Mysticetes;
    Humpback whale..................                 NA                  0               0.03                  1
    Minke whale.....................                 NA                  0               0.01                  3
    Bryde's whale...................               0.41                  0               0.01                  2
    Omura's whale...................                 NA                  0                 NA                  2
    Sei whale.......................               0.29                  0       0.03 to 0.02                  2
    Fin whale.......................                 NA                  0       0.05 to 0.04                  7
    Blue whale......................                 NA                  0                 NA                  2
Odontocetes:
    Sperm whale.....................               1.23                  1       0.02 (<0.01)                  5
    Pygmy sperm whale...............               3.19                  3            NA (NA)                  3
    Dwarf sperm whale...............                 10                 10        0.09 (0.09)                 10
    Cuvier's beaked whale...........                6.8                  7        0.04 (0.04)                  7
    Longman's beaked whale..........               0.45                  0            NA (NA)                 18
    Ginkgo-toothed beaked whale.....                  0                  0          <0.01 (0)                  2
    Blainville's beaked whale.......               1.28                  1      <0.01 (<0.01)                  2
    Killer whale....................               0.16                  0               0.08                  7
    Short-finned pilot whale........              320.0                340        0.63 (0.63)                340
    False killer whale..............               1.11                  1       0.06 (<0.01)                 10
    Melon-headed whale..............               40.0                 42        0.09 (0.09)                 42
    Pygmy killer whale..............               0.14                  0           0.02 (0)                  6
    Risso's dolphin.................               30.0                 32        0.04 (0.04)                 32
    Bottlenose dolphin..............              110.0                118        0.07 (0.07)                118
    Rough-toothed dolphin...........               0.29                  0           0.01 (0)                  9
    Fraser's dolphin................              580.0                617        0.21 (0.21)                617
    Striped dolphin.................               6.16                  7      <0.01 (<0.01)                 27
    Pantropical spotted dolphin.....              650.0                692        0.16 (0.16)                692
    Spinner dolphin.................            1,370.0              1,458          0.2 (0.2)              1,458
----------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ Densities calculated from Table 4 of Barlow (2006) using the abundance in the outer EEZ stratum and the
  surface area of the stratum give on p. 452 of Barlow (2006).
\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\ Requested (and calculated) takes expressed as percentages of the regional populations.
\4\ Requested Take Authorization increased to mean group size for species for which densities were not available
  but that have been sighted in the survey area and for species whose calculated takes were less than group
  size.

    SIO 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) 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 (including repeat exposures 
of the same individuals) can be estimated by considering the total 
marine area that would be within the 160 dB radius around the operating 
airguns, excluding areas of overlap. During the survey, the transect 
lines are widely spaced relative to the 160 dB (rms) distance (600 m 
for intermediate water depths and 400 m for deep water depths). Thus, 
the area including overlap is 1.07 times the area excluding overlap, so 
a marine mammal that stayed in the survey areas during the entire 
survey could be exposed slightly more than once, on average. However, 
it is unlikely that a particular animal would stay in the area during 
the entire survey.
    The number of different individuals potentially exposed to received 
levels greater than or equal to 160 re 1 [mu]Pa (rms) 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 excluding overlap.
    The area expected to be ensonified was determined by entering the 
planned survey lines into a MapInfo GIS, using the GIS to identify the 
relevant areas by ``drawing'' the applicable 160 dB buffer (see Table 1 
of the IHA application) around each seismic line, and then calculating 
the total area within the buffers.
    Applying the approach described above, approximately 851 km\2\ 
(approximately 1,063.8 km\2\ including the 25% contingency) would be 
within the 160 dB isopleth on one or more occasions during the survey. 
The take calculations within the study sites do not explicitly add 
animals to account for the fact that new animals (i.e., turnover) are 
not accounted for in the initial density snapshot and animals could 
also approach and enter the area ensonified above 160 dB; however, 
studies suggest that many marine mammals will 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 allow for turnover in the

[[Page 57366]]

marine mammal populations in the area during the course of the survey, 
the actual number of individuals exposed may be underestimated, 
although the conservative (i.e., probably overestimated) line-kilometer 
distances used to calculate the area may offset this. Also, the 
approach assumes that no cetaceans will move away or toward the 
tracklines as the Revelle approaches in response to increasing sound 
levels before the levels reach 160 dB. Another way of interpreting the 
estimates that follow is that they represent the number of individuals 
that are expected (in absence of a seismic program) to occur in the 
waters that will be exposed to greater than or equal to 160 dB (rms).
    SIO's estimates of exposures to various sound levels assume that 
the surveys will 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 are 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 will 
be no weather, equipment, or mitigation delays, which is highly 
unlikely.
    Table 4 (Table 4 of the IHA application) 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) during the seismic 
survey if no animals moved away from the survey vessel. The requested 
take authorization is given in the far right column of Table 4 (Table 4 
of the IHA application). The requested take authorization has been 
increased to the average mean group sizes from the surveys whose 
densities were used in the calculations, or from Jefferson et al. 
(2008) for species not sighted during the surveys.
    The estimate of the number of individual cetaceans that could be 
exposed to seismic sounds with received levels greater than or equal to 
160 dB re 1 [mu]Pa (rms) during the survey is (with 25% contingency) in 
Table 4 of this document (see Table 4 of the IHA application). That 
total (with 25% contingency) includes 0 baleen whales, 1 sperm whale, 3 
pygmy sperm whales, 5 dwarf sperm whale, 7 Cuvier's beaked whales, and 
1 Blainville's beaked whales could be taken by Level B harassment 
during the low-energy seismic survey, which would represent 0, <0.01, 
NA, 0.05, 0.04, 0.01% of the regional populations, respectively. Most 
of the cetaceans potentially taken by Level B harassment are 
delphinids: bottlenose, Fraser's, pantropical spotted, and spinner 
dolphins as well as short-finned pilot whales are estimated to be the 
most common delphinid species in the area, with estimates of 118, 617, 
692, 1,458, and 340, which would represent 0.07, 0.21, 0.16, 0.2, and 
0.63% of the affected regional populations, respectively.

Encouraging and Coordinating Research

    SIO and NSF will coordinate the planned marine mammal monitoring 
program associated with the low-energy seismic survey with other 
parties that express interest in this activity and area. SIO and NSF 
will coordinate with applicable U.S. agencies (e.g., NMFS), and will 
comply with their requirements.

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 is subsistence hunting for sperm whales, as well as other 
cetaceans and dugongs in Indonesia (Reeves, 2002; Marsh et al., n.d.). 
The hunting of Bryde's whales in the Philippines appears to be 
prohibited now, but dugongs are still taken there, as well as in Papua 
New Guinea (Marsh et al., n.d.). SIO and NMFS do not expect the 
activities to have any impact on the availability of species or stocks 
of marine mammals in the study area for subsistence users that 
implicate MMPA section 101(a)(5)(D).

Negligible Impact and Small Numbers Analysis Determination

    As a preliminary matter, NMFS typically includes our negligible 
impact and small numbers analyses and determinations under the same 
section heading of our Federal Register notices. Despite co-locating 
these terms, NMFS acknowledges that negligible impact and small numbers 
are distinct standards under the MMPA and treat them as such. The 
analyses presented below do not conflate the two standards; instead, 
each standard has been considered independently and NMFS has applied 
the relevant factors to inform our negligible impact and small numbers 
determinations.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival.'' In making a negligible impact determination, NMFS evaluated 
factors such as:
    (1) The number of anticipated injuries, serious injuries, or 
mortalities;
    (2) The number, nature, and intensity, and duration of Level B 
harassment (all relatively limited); and
    (3) The context in which the takes occur (i.e., impacts to areas of 
significance, impacts to local populations, and cumulative impacts when 
taking into account successive/contemporaneous actions when added to 
baseline data);
    (4) 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);
    (5) Impacts on habitat affecting rates of recruitment/survival; and
    (6) The effectiveness of monitoring and mitigation measures.
    For reasons stated previously in this document, in the notice of 
the proposed IHA (78 FR 33811, June 5, 2013) and based on the following 
factors, the specified activities associated with the marine seismic 
survey are not likely to cause PTS, or other non-auditory injury, 
serious injury, or death. The factors include:
    (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 potential for temporary or permanent hearing impairment is 
relatively low and would likely be avoided through the implementation 
of the shut-down measures; and
    (3) 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 SIO's planned marine seismic surveys, and none 
are authorized by NMFS. Table 4 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 (see ``Potential 
Effects on Marine

[[Page 57367]]

Mammals'' section above) in this notice, 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 plan to 
implement mitigation, monitoring, and reporting measures to minimize 
impacts to marine mammals. Additionally, the seismic survey will not 
adversely impact marine mammal habitat.
    For the other marine mammal species that may occur within the 
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). 
Additionally, the seismic survey will 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, and some animals may only be exposed to and harassed by 
sound for less than a day.
    Of the 26 marine mammal species under NMFS jurisdiction that may or 
are known to likely occur in the study area, five are listed as 
threatened or endangered under the ESA: Humpback, sei, fin, blue, and 
sperm whales. These species are also considered depleted under the 
MMPA. Of these ESA-listed species, incidental take has been requested 
to be authorized for humpback, sei, fin, blue, and sperm whales. There 
is generally insufficient data to determine population trends for the 
other depleted species in the study area. To protect these animals (and 
other marine mammals in the study area), SIO must cease or reduce 
airgun operations if any marine mammal enters designated zones. No 
injury, serious injury, or mortality is expected to occur 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.
    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 of this document.
    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 determined, provided that the aforementioned mitigation 
and monitoring measures are implemented, the impact of conducting a 
low-energy marine seismic survey in the tropical western Pacific Ocean, 
September to October 2013, may result, at worst, in a modification in 
behavior and/or low-level physiological effects (Level B harassment) of 
certain species of marine mammals.
    While behavioral modifications, including temporarily vacating the 
area during the operation of the airgun(s), may be made by these 
species to avoid the resultant acoustic disturbance, the availability 
of alternate areas within these areas for species and the short and 
sporadic duration of the research activities, have led NMFS to 
determine that the taking by Level B harassment from the specified 
activity will have a negligible impact on the affected species in the 
specified geographic region. NMFS believes that the length of the 
seismic survey, the requirement to implement mitigation measures (e.g., 
shut-down of seismic operations), and the inclusion of the monitoring 
and reporting measures, will reduce the amount and severity of the 
potential impacts from the activity to the degree that it will have a 
negligible impact on the species or stocks in the action area.
    NMFS has determined, provided that the aforementioned mitigation 
and monitoring measures are implemented, that the impact of conducting 
a low-energy marine seismic survey in the tropical western Pacific 
Ocean, September to October 2013, 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. 
The requested take estimates represent small numbers relative to the 
affected species or stock sizes (i.e., all are less than 1%). See Table 
4 for the requested authorized take numbers of marine mammals.

Endangered Species Act

    Of the species of marine mammals that may occur in the survey area, 
several are listed as endangered under the ESA, including the humpback, 
sei, fin, blue, and sperm whales. SIO did not request take of 
endangered North Pacific right whales due to the low likelihood of 
encountering this species during the cruise. Under section 7 of the 
ESA, NSF, on behalf of SIO, has initiated formal consultation with the 
NMFS, Office of Protected Resources, Endangered Species Act Interagency 
Cooperation Division, on this low-energy seismic survey. NMFS's Office 
of Protected Resources, Permits and Conservation Division, has also 
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 under section 101(a)(5)(D) of the MMPA on 
threatened and endangered marine mammals for this activity. These two 
consultations were consolidated and addressed in a single Biological 
Opinion addressing the direct and indirect effects of these 
interdependent actions. In September 2013, NMFS issued a Biological 
Opinion and concluded that the action and issuance of the IHA are not 
likely to jeopardize the continued existence of cetaceans and sea 
turtles and included an Incidental Take Statement (ITS) incorporating 
the requirements of the IHA as Terms and Conditions. The Biological 
Opinion also concluded that designated critical habitat of these 
species does not occur in the action area and would not be affected by 
the survey.

National Environmental Policy Act

    With SIO's complete application, SIO and NSF provided NMFS an 
``Environmental Analysis of a Low-Energy Marine Geophysical Survey by 
the R/V Roger Revelle in the Tropical Western Pacific Ocean, September-
October 2013'' (Environmental Analysis), prepared by LGL Ltd., 
Environmental Research Associates, on behalf of SIO and NSF. The 
Environmental Analysis analyzes the direct, indirect, and cumulative 
environmental impacts of the specified activities on marine mammals 
including those listed as threatened or endangered under the ESA. NMFS, 
after review and evaluation of the NSF and SIO Environmental Analysis 
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, prepared an independent Environmental 
Assessment (EA) titled ``Environmental Assessment on the Issuance of an 
Incidental Harassment Authorization to the Scripps Institution of 
Oceanography to

[[Page 57368]]

Take Marine Mammals by Harassment Incidental to a Low-Energy Marine 
Geophysical Survey in the Tropical Western Pacific Ocean, September to 
October 2013.'' After considering the EA, the information in the IHA 
application, Biological Opinion, and the Federal Register notice, as 
well as public comments, NMFS has determined that the issuance of the 
IHA is not likely to result in significant impacts on the human 
environment and has prepared a Finding of No Significant Impact 
(FONSI). An Environmental Impact Statement is not required and will not 
be prepared for the action.

Authorization

    NMFS has issued an IHA to SIO for the take, by Level B harassment, 
of small numbers of marine mammals incidental to conducting a low-
energy marine seismic survey in the tropical western Pacific Ocean, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.

    Dated: September 13, 2013.
Helen M. Golde,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2013-22671 Filed 9-17-13; 8:45 am]
BILLING CODE 3510-22-P