Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey in the Gulf of Mexico, April to May 2013, 33369-33392 [2013-13185]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 78, Number 107 (Tuesday, June 4, 2013)]
[Notices]
[Pages 33369-33392]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-13185]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC389


Takes of Marine Mammals Incidental to Specified Activities; Low-
Energy Marine Geophysical Survey in the Gulf of Mexico, April to May 
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 U.S. Geological Survey 
(USGS) to take marine mammals, by Level B harassment, incidental to 
conducting a low-energy marine geophysical (i.e., seismic) survey in 
the deep water of the Gulf of Mexico, April to May 2013.

DATES: Effective April 17 through June 10, 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 IHA application containing a list of the references 
used in this document may be obtained by writing to the above address, 
telephoning the contact listed here (see FOR FURTHER INFORMATION 
CONTACT) or visiting the internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.

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

[[Page 33370]]

and reporting of such takings. NMFS has defined ``negligible impact'' 
in 50 CFR 216.103 as ``. . . an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the United States can apply for an authorization 
to incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) of the MMPA establishes a 45-day time limit for 
NMFS'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].
    The USGS has prepared an ``Environmental Assessment and 
Determination Pursuant to the National Environmental Policy Act, 42 
U.S.C. 4321 et seq. and Executive Order 12114 Low-Energy Marine Seismic 
Survey by the U.S. Geological Survey in the Deepwater Gulf of Mexico, 
April-May 2013'' (EA). USGS's EA incorporates an ``Environmental 
Assessment of a Low-Energy Marine Geophysical Survey by the U.S. 
Geological Survey in the Northwestern Gulf of Mexico, April-May 2013,'' 
prepared by LGL Ltd., Environmental Research Associates, on behalf of 
USGS, which is also available at the same Internet address as well as 
on the USGS's environmental compliance Web site, which is available 
online at: https://woodshole.er.usgs.gov/project-pages/environmental_compliance/. 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 or 
endangered. The NMFS Biological Opinion is available online at: https://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.

Summary of Request

    On November 5, 2012, NMFS received an application from the USGS 
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 within the U.S. Exclusive Economic 
Zone in the deep water of the Gulf of Mexico during April to May 2013. 
The USGS plans to use one source vessel, the R/V Pelican (Pelican), or 
similar vessel, and a seismic airgun array to collect seismic data as 
part of the ``Gas Hydrates Project'' in the deep water of the northwest 
Gulf of Mexico. The USGS plans to use conventional low-energy, seismic 
methodology and ocean bottom seismometers (OBSs) to acquire the data 
necessary to delineate the distribution, saturation, and thickness of 
sub-seafloor methane hydrates and to image near-seafloor structure 
(e.g., faults) at high-resolution. In addition to the planned 
operations of the seismic airgun array and hydrophone streamer, USGS 
intends to operate a sub-bottom profiler continuously throughout the 
survey. On February 20, 2013, NMFS published a notice in the Federal 
Register (78 FR 11821) 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 USGS has requested an authorization to take 
19 species of marine mammals by Level B harassment. Take is not 
expected to result from the use of the 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 (4.5 knots [kts]; 8.1 kilometers per hour [km/
hr]; 5.0 miles per hour [mph]) during seismic acquisition within the 
survey, for a relatively short period of time (approximately 8 days of 
airgun operations out of 15 total operational days). It is likely that 
any marine mammal would be able to avoid the vessel.

Description of the Specified Activity

    USGS planned to conduct a low-energy seismic survey at two sites 
that have been studied as part of the Gulf of Mexico Gas Hydrates Joint 
Industry Project. The GC955 (i.e., Green Canyon lease block 955) and 
WR313 (i.e., Walker Ridge lease block 313) study sites are located in 
the deep water of the northwestern GOM (see Figure 1 of the IHA 
application). Study site GC955 will be surveyed first, followed by 
WR313. The seismic survey is scheduled to take place for approximately 
eight days (out of 15 total operational days) in April to May 2013.
    The purpose of USGS's seismic survey, which is to be carried out by 
personnel from the USGS Gas Hydrates Project, is to develop technology 
and to collect data to assist in the characterization of marine gas 
hydrates in order to respond to a need to better understand their 
potential as an energy source and their impact on seafloor stability. 
In addition to these two topics, the USGS Gas Hydrates Project also 
researches the impact of climate change on natural gas hydrates and the 
impact of degassing from shallow sub-seafloor and permafrost gas 
hydrates on climate change. However, that is not the purpose of this 
specific project. These goals of the GOM research program are 
consistent with the USGS mission to ``provide reliable scientific 
information to describe and understand the Earth; minimize loss of life 
and property from natural disasters; manage water, biological, energy, 
and mineral resources; and enhance and protect our quality of life.'' 
The objectives of this seismic research program also coincide with the 
goals articulated in the USGS Energy and Minerals Science Strategy 
(Ferrero et al., 2012). Through the USGS Energy Resources Program 
(ERP), which partially funds the USGS Gas Hydrates Project, the USGS 
conducts research to enhance understanding of the geologic occurrence, 
formation, and evolution of oil, gas, coal, and uranium resources. The 
ERP is responsible for applying the results of this research to the 
assessment of, economic and environmental impact of development of 
these resources, as well, and making this knowledge public. The ERP 
provides accurate, dependable, and unbiased assessments of the world's 
energy resources and associated hazards for use in formulating policies 
at local, state, and Federal levels. As an agency whose mission is 
entirely scientific, the USGS has no authority to exploit natural 
resources.
    The target sites for the GOM methane hydrates seismic 
characterization study

[[Page 33371]]

have been extensively studied, including detailed logging while 
drilling (LWD), and are known to hold thick sequences of sand 
containing high saturations of gas hydrate. The purpose of this new 
seismic acquisition is to expand outward from the boreholes the 
detailed characterization that has been accomplished there and to 
develop and calibrate improved geophysical techniques for gas hydrate 
characterization, which may in some cases obviate further scientific 
drilling.
    The need for this activity is related to the inadequacy of existing 
seismic data to fully characterize the gas hydrate deposits and nearby 
geologic structures. The available industry data for the locations of 
the survey were acquired with parameters that targeted deep (in some 
cases, sub-salt) hydrocarbon occurrences. Exhaustive analysis of these 
existing data during site evaluation (Hutchinson et al., 2009a; 2009b) 
and before and after the LWD expedition underscored the inadequacy of 
these data for complete characterization of the gas hydrate deposits 
and relevant geologic structures. Specifically, the existing data do 
not appropriately image the shallow sub-seafloor, including potential 
gas migration pathways, and do not provide appropriate data for 
regional estimates of gas hydrate saturations through analysis of 
compressional to shear wave conversions. If new seismic data designed 
to address these deficiencies are not acquired, then researchers will 
be unable to constrain whether faults intersect the hydrate-bearing 
sediments and how extensive the hydrate-bearing sediments may be. The 
new seismic data will also expand scientific expertise in using 
shipborne, instead of drilling, data to estimate hydrate saturations 
within sediment formations.
    The survey will involve one source vessel, most likely the R/V 
Pelican (Pelican) or a similar vessel. USGS will deploy two (each with 
a discharge volume of 105 cubic inch [in\3\]) Generator Injector (GI) 
airgun array as a primary energy source at a tow depth of 3 m (9.8 ft). 
A subset of the survey lines will be repeated using a single 35 in\3\ 
GI airgun. The receiving system will consist of one 450 meter (m) 
(1,476.4 feet [ft]) long, 72-channel hydrophone streamer and 25 ocean 
bottom seismometers (OBSs). 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. The OBSs record the returning acoustic signals internally for 
later analysis. Regardless of which energy source is used, the 
calculated isopleths for the two GI (105 in\3\) airguns will be used.
    At each of the two study sites, 25 OBSs will be deployed and a 
total of approximately 700 km (378 nautical miles [nmi]) of survey 
lines will be collected in a grid pattern (see Figure 1 of the IHA 
application). The water depth will be 1,500 to 2,000 m (4,921.3 to 
6,561.7 ft) at each study site). All planned seismic data acquisition 
activities will be conducted by technicians provided by USGS with 
onboard assistance by the scientists who have planned the study. The 
Principal Investigators are Dr. Seth Haines (USGS Energy Program, 
Denver, Colorado) and Mr. Patrick Hart (USGS Coastal and Marine 
Geology, Santa Cruz, California). 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 equipment recovery) will 
consist of approximately 1,480 km (799.1 nmi) of transect lines 
(including turns) in the survey area in the deep water of the 
northwestern Gulf of Mexico (GOM) (see Figure 1 of the IHA 
application). In addition to the operation of the airgun array, a 
Knudsen sub-bottom profiler will also likely be operated from the 
Pelican continuously throughout the cruise. USGS will not be operating 
a multibeam system, the Pelican is not equipped with this equipment. 
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 USGS's estimated 
take calculations, 25% has been added for those additional operations.

Dates, Duration, and Specified Geographic Region

    The planned project will be located near the GC955 and WR313 study 
sites in the deep water of the northwest Gulf of Mexico and would have 
a total duration of approximately 15 operational days occurring during 
the April through May 2013 timeframe, which will include approximately 
8 days of active seismic airgun operations. Water depth at the site is 
approximately 2,000 m (6561.7 ft). The total survey time would be 
approximately 96 hours at each site. The survey is scheduled from April 
17 to May 6, 2013. The Pelican is expected to depart and return to 
Cocodrie, Louisiana, with no intermediate stops.
    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).
    The latitude and longitude for the bounds of the two study sites 
are:

WR313:
    91[deg]34.75' West to 91[deg]46.75' West
    26[deg]33.75' North to 26[deg]45.75' North
GC955:
    90[deg]20.0' West to 90[deg]31.75' West
    26[deg]54.1' North to 27[deg]6.0' North

    NMFS outlined the purpose of the program in a previous notice for 
the proposed IHA (78 FR 11821, February 20, 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 proposed IHA 
notice (78 FR 11821, February 20, 2013), the IHA application, EA, and 
associated documents referenced above this section.

Comments and Responses

    A notice of the proposed IHA for the USGS seismic survey was 
published in the Federal Register on February 20, 2013 (78 FR 11821). 
During the 30-day public comment period, NMFS received comments from 
the Marine Mammal Commission (Commission), International Association of 
Geophysical Contractors (IAGC) and the America Petroleum Institute 
(API) (hereinafter referred to as Industry Associations), Center for 
Biological Diversity (CBD), and numerous private citizens. The 
Commission, Industry Associations, CBD, and private citizen's comments 
are online at: https://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 the USGS to 
re-estimate the proposed exclusion and buffer zones and associated 
takes of marine mammals using site-specific information--if the 
exclusion and buffer zones and numbers of takes are not re-estimated, 
require the USGS to provide a detailed justification for (1) basing the 
exclusion and buffer zones for the proposed survey on modeling that 
does not incorporate site-specific environmental parameters and has 
been documented to underestimate the size of those zones and (2) how 
tow depth was incorporated into the model.
    Response: With respect to the Commission's first point regarding 
re-estimating the proposed exclusion and

[[Page 33372]]

buffer zones and associated takes of marine mammals using site-specific 
information, based upon the best available information and NMFS's 
analysis of the likely effects of the specified activity on marine 
mammals and their habitat, NMFS is satisfied that the data supplied by 
USGS are sufficient for NMFS to conduct its analysis and support the 
determinations under the MMPA, Endangered Species Act of 1973 (ESA; 16 
U.S.C. 1531 et seq.), and the National Environmental Policy Act (NEPA). 
The identified exclusion and buffer zones are appropriate for the 
survey, and additional field measurements are not necessary at this 
time. Thus, for this survey, NMFS will not require USGS to re-estimate 
the proposed exclusion zones and buffer zones and associated number of 
marine mammal takes using operational and site-specific environmental 
parameters.
    With respect to the Commission's second point on how tow depth was 
incorporated into the model, USGS has modeled the exclusion and buffer 
zones in the action area based on Lamont-Doherty Earth Observatory (L-
DEO) of Columbia University's 2003 (Tolstoy et al., 2004) and 2007-2008 
(Tolstoy et al., 2009; Diebold et al., 2010) peer-reviewed, calibration 
studies in the GOM. Received levels have been predicted and modeled by 
L-DEO for a number of airgun configurations and tow depths (e.g., 36-
airgun array and a single 1900LL 40 in\3\ airgun), including two 105 
in\3\ GI airguns, in relation to distance and direction from airguns 
(see Figure 2 of the IHA application). This modeling approach uses ray 
tracing for the direct wave traveling from the array to the receiver 
and its associated source ghost (reflection at the air-water interface 
in the vicinity of the array), in a constant-velocity half space 
(infinite homogeneous ocean layer, unbounded by a seafloor). USGS's EA 
and the conclusions in Appendix H of the ``Programmatic Environmental 
Impact Statement/Overseas Environmental Impact Statement for Marine 
Seismic Research Funded by the National Science Foundation or Conducted 
by the U.S. Geological Survey'' (NSF/USGS PEIS) include detailed 
information on the study, their modeling process of the experiment in 
shallow, intermediate, and deep water. It also shows that L-DEO's model 
represents the actual produced sound levels, particularly within the 
first few kilometers, where the predicted zones (i.e., exclusion and 
buffer zones) lie. The conclusions show that USGS model represents the 
actual produced sound levels. At greater distances, local oceanographic 
variations begin to take effect, and the model tends to over predict.
    Because the modeling matches the observed measurement data, the 
authors of these peer-reviewed papers concluded that those using the 
models to predict zones can continue to do so, including predicting 
exclusion and buffer zones around the vessel for various depths. At 
present, L-DEO's model does not account for site-specific environmental 
conditions and the calibration study analysis of the model predicted 
that using site-specific environmental conditions. In addition, the 
calibration study analysis of the model predicted that using site-
specific information may actually estimate less conservative exclusion 
zones at greater distances.
    While it is difficult to estimate exposures of marine mammals to 
acoustic stimuli, USGS's approach to quantifying the exclusion and 
buffer zones uses the best available scientific information (as 
required by NMFS regulations) and estimation methodologies. After 
considering this comment and evaluating the respective approaches for 
establishing exclusion and buffer zones, NMFS has determined that 
USGS's approach and corresponding monitoring and mitigation measures 
will effect the least practicable impact on affected marine mammal 
species or stocks.
    Comment 2: The Commission recommends that NMFS require USGS to re-
estimate the numbers of takes by including those takes that would occur 
if the survey repeats a subset of the tracklines using the single 
airgun, which would be in addition to takes that occur during turns and 
equipment testing or that occur because of equipment failure/poor data.
    Response: On page 21 of the USGS's IHA application, USGS states 
that ``. . . ensonified areas calculated using the planned number of 
line-kilometers have been increased by 25% to accommodate turns, lines 
that may need to be repeated, equipment testing, etc.'' The IHA 
application states that approximately 700 km of survey lines will be 
conducted at each site and that the total survey time would be 
approximately 96 hours (i.e., 700 km + 25% [175 km] = 875 km). As a 
result, the request for a 25% increase accounts for turns, lines that 
may be repeated and equipment testing. Also, the repeated lines in the 
survey grid may increase the number of potential exposures to the sound 
source but may not increase the number of individuals of marine mammals 
exposed as the USGS's take calculation methodology assumes that all 
marine mammals are stationary.
    Comment 3: The Commission recommends that NMFS prohibit the use of 
only a 15-minute pause following the sighting of a mysticete or large 
odontocete in the exclusion zone and extend that pause to cover the 
maximum dive times of the species likely to be encountered prior to 
initiating ramp-up procedures after a shut-down.
    Response: NMFS would like to clarify the Commission's understanding 
of two conditions within the IHA--one related to turning on the airguns 
(ramp-up) after a shut-down due to a marine mammal sighting about to 
enter or within the exclusion zone, and the other related to a ramp-up 
after an extended shut-down (i.e., the 15 minute pause due to equipment 
failure or routine maintenance).
    To clarify, the IHA requires the Pelican to shut-down the airguns 
when a Protected Species Observer (PSO) sees a marine mammal within, 
approaching, or entering the relevant exclusion zone for cetaceans. 
Following a shut-down, the Pelican would only ramp-up the airguns if a 
marine mammal had exited the exclusion zone or if the PSO had not seen 
the animals within the relevant exclusion zone for 15 minutes for 
species with shorter dive times (i.e., small odontocetes and pinnipeds) 
or 30 minutes for species with longer dive durations (i.e., mysticetes 
and large odontocetes, including sperm, pygmy sperm, dwarf sperm, 
killer, and beaked whales).
    NMFS believes that 30 minutes is an adequate length for the 
monitoring period prior to the ramp-up of the airgun array after 
sighting a mysticete or large odontocete for the following reasons:
     The Pelican can transit roughly 4.5 knots; the ship would 
move 1.1 km (0.6 nmi) in 15 minutes or 2.3 km (1.3 nmi) in 30 minutes. 
At this distance, the vessel will have moved 15.7 times (1.1 km/0.07 
km) in 15 minutes and 32.9 times (2.3 km/0.07 km) in 30 minutes away 
from the distance of the original 180 dB exclusion zone (70 m [229.7 
ft] for two 105 in\3\ airguns) from the initial sighting.
     The relevant exclusion zone for cetaceans is relatively 
small (i.e., 70 m for cetaceans for the two 105 in\3\ GI airguns). 
Extending the monitoring period for a relatively small exclusion zones 
would not meaningfully increase the effectiveness of observing marine 
mammals approaching or entering the exclusion zone for the full source 
level and would not further minimize the potential for take.
     Because a significant part of their movement is vertical 
(deep-diving), it is

[[Page 33373]]

unlikely that a submerged mysticete or large odontocete would move in 
the same direction and speed (roughly 4.5 knots) with the vessel for 30 
minutes. If a mysticete or large odontocete's maximum underwater dive 
time is 45 minutes, then there is only a one in three chance that the 
last random surfacing could occur within the 70 m exclusion zone.
     The PSOs are constantly monitoring the horizon and the 
exclusion zones during the 30-minute period. PSOs can observe to the 
horizon from the height of the Pelican's observation deck and should be 
able to say with a reasonable degree of confidence whether a marine 
mammal would be encountered within this distance before resuming the 
two GI airgun operations at full power.
    Next, NMFS intends to clarify the monitoring period associated with 
an extended shut-down (i.e., the 15-minute pause due to equipment 
failure or routine maintenance). During active seismic operations, 
there are occasions when the Pelican crew will need to temporarily 
shut-down the airguns due to equipment failure or for maintenance. 
Thus, an extended shut-down is not related to the PSO detecting a 
marine mammal within, approaching, or entering the relevant exclusion 
zones. However, the PSOs are still actively monitoring the relevant 
exclusion zones for cetaceans and pinnipeds.
    In conclusion, NMFS has designed monitoring and mitigation measures 
to comply with the requirement that incidental take authorizations must 
include means of effecting the least practicable impact on marine 
mammal species and their habitat. The effectiveness of monitoring is 
science-based, and monitoring and mitigation measures must be 
``practicable.'' NMFS believes that the framework for visual monitoring 
will: (1) be effective at spotting almost all species for which USGS 
has requested take, and (2) that imposing additional requirements, such 
as those suggested by the Commission, would not meaningfully increase 
the effectiveness of observing marine mammals approaching or entering 
the exclusion zones and further minimize the potential for take.
    In the case of an extended shut-down, due to equipment failure or 
routine maintenance, the Pelican's crew will turn on the airguns and 
follow the mitigation and monitoring procedures for a ramp-up after a 
period of 15 minutes. Again, the PSOs will monitor the full exclusion 
zones for marine mammals and will implement a shut-down, if necessary. 
After considering this comment and evaluating the monitoring and 
mitigation requirements to be included in the IHA, NMFS has determined 
that USGS's approach and corresponding monitoring and mitigation 
measures will effect the least practicable impact on affected marine 
mammal species or stocks.
    Comment 4: The Commission recommends that NMFS consult with the 
USGS and other relevant entities (e.g., NSF 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 taking and the numbers of marine mammals taken--the 
assessment should account for availability biases and the detection 
biases of the seismic survey observers.
    Response: Several studies have reported on the abundance and 
distribution of marine mammals inhabiting the GOM, and the USGS has 
incorporated these data into their analyses used to predict marine 
mammal take in their IHA applications. NMFS believes that the USGS's 
approach for estimating abundance in the survey areas (prior to the 
survey) is the best available approach.
    There will be periods of transit time during the cruise, and 
Protected Species Observers (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 it is unlikely that 
the information gathered from these cruises alone would result in any 
statistically robust conclusions for any particular species because of 
the small number of animals typically observed.
    NMFS acknowledges the Commission's recommendations and is open to 
further coordination with the Commission, USGS, and other entities, to 
develop, validate, and implement a monitoring program that will provide 
or contribute towards a more scientifically sound and reasonably 
accurate assessment of the types of marine mammal taking and the number 
of marine mammals taken. However, the cruise's primary focus is marine 
seismic research, and the surveys may be operationally limited due to 
considerations such as location, time, fuel, services, and other 
resources.
    Comment 5: The Commission recommends that NMFS work with USGS and 
NSF to analyze monitoring data to assess the effectiveness of ramp-up 
procedures as a mitigation measure for geophysical surveys.
    Response: NMFS acknowledges the Commission's request for an 
analysis of ramp-ups and will work with USGS and NSF to help identify 
the effectiveness of the mitigation measure for seismic surveys. The 
IHA requires that PSOs on the Pelican 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 USGS and NSF 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 6: The Industry Associations state that environmental 
consequences should be evaluated using the best available science that 
properly discriminates between empirical fact and conjecture; and 
reflects the probabilities of effect and weight of the evidence in 
presenting the risks of adverse impacts of anthropogenic sound upon 
marine species.
    Response: NMFS's determinations, in order to meet the requirements 
of section 101(a)(5)(D) of the MMPA, use peer-reviewed data that are 
based on the best science available regarding the biology of animals 
affected and the propagation of sounds from sources

[[Page 33374]]

during the seismic survey. This information is supported by USGS's IHA 
application and EA.
    Comment 7: The Industry Associations state that reasonable 
threshold for anticipation of adverse effects should be established 
before mitigation is demanded and that mitigation should be effective 
and practicable.
    Response: NMFS's proposed action is triggered by USGS requesting an 
IHA to take marine mammals incidental to conducting a low-energy marine 
seismic survey in the deep water of the GOM. The USGS's seismic survey 
has the potential to cause marine mammals to be behaviorally disturbed 
by exposing them to elevated levels of sound which, as NMFS has 
explained, is anticipated to result in take that would otherwise be 
prohibited by the MMPA. The USGS, therefore, requires an IHA for 
incidental take and has requested that NMFS provide it through the 
issuance of an IHA under section 101(a)(5)(D) of the MMPA. IHAs must 
include requirements or conditions pertaining to the monitoring and 
reporting of such taking in large part to better understand the effects 
of such taking on the species.
    Based on the analysis contained in the USGS's EA and IHA 
application, NMFS notice of the proposed IHA (78 FR 11821, February 20, 
2013), and this document, of the likely effects (including potential 
adverse effects) of the specified activity on marine mammals and their 
habitat, which is based on the best scientific information available, 
and taking into consideration the implementation of the mitigation and 
monitoring measures, NMFS finds that USGS's planned research 
activities, will result in the incidental take of small numbers of 
marine mammals, by Level B harassment only, and that the total taking 
from the low-energy marine seismic survey will have a negligible impact 
on the affected species or stocks of marine mammals; and that impacts 
to affected species or stocks of marine mammals have been mitigated to 
the lowest level practicable. Therefore, per our implementing 
regulations, NMFS shall issue the IHA to USGS.
    Also, USGS has proposed to implement the monitoring and mitigation 
measures included in the IHA in their IHA application and EA. They have 
determined that the measures are effective and practicable as described 
in this Federal Register notice, and NMFS concurs with their 
determination.
    Comment 8: The Industry Associations state that the USGS IHA 
application refers to related NEPA documents that results in a much 
less robust EA which contains conjectural risk assessments and 
unwarranted mitigation zone requirements. The NSF, USGS and NMFS 
expended significant resources over a five-year period in development 
of the 2011 NSF/USGS PEIS to develop a consistent, standardized 
approach to frequent IHA applications for seismic surveys. The IHA 
application, while referencing the 2011 NSF/USGS PEIS, does not appear 
to fully utilize its extensive environmental assessment indicating 
minimal impacts from low energy seismic surveys not adopts its more 
moderate, generic mitigation requirements. In fact, the USGS IHA 
application seems to require larger buffer and exclusion zones without 
information or explanation of what new or site-specific risk factors 
justify them.
    Response: In many sections throughout USGS's EA, the USGS refers to 
the NSF/USGS PEIS for comprehensive reviews on relevant background and 
more specific information, and incorporates them by reference. USGS has 
proposed the buffer and exclusion zones as well as monitoring and 
mitigation measures that are included in the IHA in their IHA 
application and EA, and they have determined that the zones and 
measures are effective and practicable.
    Comment 9: The Industry Associations states that the requested IHA 
application has minimal potential for substantive, adverse 
environmental consequences. The benefits of the action are significant. 
Thus, an IHA for non-lethal, incidental take of small numbers of marine 
mammals should be issued promptly.
    Response: Generally, under the MMPA, NMFS shall authorize the 
harassment of small numbers of marine mammals incidental to an 
otherwise lawful activity, provided NMFS finds that the taking will 
have a negligible impact on the species or stock, will not have an 
unmitigable adverse impact on the availability of the species or stock 
for subsistence uses (where relevant), and if the permissible methods 
of taking and requirements pertaining to the mitigation, monitoring, 
and reporting of such takings are set forth to achieve the least 
practicable adverse impact. 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.'' NMFS believes that the short time period 
of the seismic survey, the small size of the airgun array, 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. USGS has applied for an 
IHA and has met the necessary requirements for issuance of an IHA for 
small numbers of marine mammals, by Level B harassment, incidental to 
the low-energy marine seismic survey in the deep water of the GOM. 
Therefore, NMFS has issued an IHA to USGS.
    Comment 10: The Industry Associations state that a clear and 
consistently applied regulatory process is needed where the various 
factors are evaluated, conservative factors reflecting reasonable 
probabilities are documented in a way that the regulated community can 
see the layers of conservative factors and the balancing of empirical 
facts, conjecture and observed field effects for decisions are clearly 
explained.
    Response: To the maximum extent possible, NMFS applies a clear and 
consistent process under section 105(a)(5)(A) and (D) of the MMPA. 
Section 101(a)(5)(D) of the MMPA established an expedited process by 
which citizens of the United States can apply for an authorization to 
incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) of the MMPA establishes a 45-day time limit for 
NMFS's review of an application followed by a 30-day public notice and 
comment period on any proposed authorizations for the incidental 
harassment of small numbers of marine mammals. Within 45 days of the 
close of the public comment period, NMFS must either issue or deny the 
authorization. In requesting an IHA from NMFS, USGS provided the 
information detailed in 14 sections specified in 50 CFR 216.104 for its 
specified activity NMFS determined that the USGS's IHA request was 
adequate and complete, and began a public review process by publishing 
it in the Federal Register. NMFS makes available the IHA application, 
proposed IHA, related NEPA documents, etc. online at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.
    In order to issue an ITA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable adverse 
impact on such species or stock and its habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar

[[Page 33375]]

significance, and the availability of such species or stock for taking 
for certain subsistence uses.
    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.
    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 (i.e., 
the manner and degree in which the measure is likely to reduce adverse 
impacts to marine mammals, the likely effectiveness of the measures, 
and the practicability of implementation).
    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.
    Comment 11: The Industry Associations state that the evaluation of 
impacts from marine sound sources continues to blur the distinctions 
between exposure and effect leading to unsupportable overestimates of 
the risks to marine wildlife. The USGS IHA in fact validates this 
concern: ``It is common practice to estimate how many mammals would be 
present within a particular distance of industrial activities and/or 
exposed to a particular level of sound. In most cases, this approach 
likely overestimates the numbers of marine mammals that would be 
affected in some biologically important manner.''
    Response: In USGS and NMFS's analysis, we focus qualitatively on 
the different ways that exposure to signals from the seismic airguns 
may affect marine mammals (e.g., sensory impairment, masking, 
physiological responses, behavioral disturbance, etc.) that may be 
classified as behavioral harassment or injury and may be likely to 
adversely affect the species or stocks of marine mammals in the GOM 
study area. Although responses to sound are highly variable and 
context-specific, NMFS uses acoustic criteria, estimates of take of 
marine mammals to various sound sources and modeled received levels are 
used as a method in to estimate the number of individuals that would 
potentially be taken by Level B harassment and to meet NMFS's small 
numbers and negligible impact determinations under the MMPA.
    Comment 12: The Industry Associations do not believe the principle 
of equating received sound levels to ``takes'' has been subjected to 
public comment or peer review as is required. This interpretive 
application of exposure as a proxy for incidental take is not supported 
by the MMPA, which requires that harassment must occur (16 U.S.C. 
1362(18)(A)). In the case of Level B harassment, the disturbance must 
be related to a disruption in behavioral patterns, not just a change in 
behavior (16 U.S.C. 1362(18)(A)(ii), 1362(18)(D)).
    Further, the Industry Associations state that there is no 
jurisdiction precedent defining whether sound occurring at a certain 
level constitutes a take. It is simply not enough for an animal to be 
exposed to a sound. For there to be a ``take'' based on harassment, 
there must be disruption in a pattern of behavior, and it must be 
caused by an act of pursuit, torment or annoyance (16 U.S.C. 
1362(18)(A)).
    Response: 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]. Because the behavioral and/or 
physiological responses of the majority of the marine mammals exposed 
to noise from the airgun array cannot be detected or measured, a method 
is needed to estimate the number of individuals that will be taken, 
pursuant to the MMPA, based on the proposed action. To this end, NMFS 
uses established acoustic criteria that estimate at what received level 
(when exposed to seismic airguns) Level B harassment of marine mammals 
would occur. NMFS has published notices in the Federal Register 
initiating a 30-day public review process for specified activities 
producing anthropogenic noise, and specifically seismic surveys, for 
over a decade.
    Comment 13: The Industry Associations state that the USFWS in its 
Polar Bear and Walrus incidental take regulations clarified how it 
evaluates the potential effects of sound on marine life by clearly 
labeling ``exposures'' and more clearly differentiating ``exposures'' 
from ``takes.''
    The USGS IHA application and associated EA do not provide this 
clarity and thus overstate the environmental effects of the action. In 
addition, the USGS IHA application does not clearly explain when an 
exposure has a behavioral effect, whether this rises to be a countable 
take and finally whether any of this is biologically significant at 
either an individual or population level. The overestimate of effect is 
especially acute for a ``low-energy'' seismic survey. The fact that in 
the IHA, USGS proposes to use large seismic source arrays as a proxy 
for a small two source element operation and that it uses shallow-water 
sound propagation as a proxy for deep water propagation further adds to 
the overestimate of potential acoustic impacts.
    Response: For USGS's action, NMFS uses a reasonable estimate of 
exposures that may elicit a response that rises to the level of 
``take'' definition. In the EA and IHA application, the number of 
different individuals that could be exposed to airguns sounds with 
received levels greater than or equal to

[[Page 33376]]

160 dB (rms) on one or more occasions can be estimated by considering 
the total marine area that would be within the 160 dB (rms) radius 
around the operating seismic source on at least one occasion, along 
with the expected density of animals in the area. The number of 
possible exposures (including repeated exposures of the same 
individuals) can be estimated by considering the total marine area that 
would be within the 160 dB (rms) radius around the operating airguns, 
including areas of overlap. During the planned survey, the transect 
lines in the square grid are closely spaced (100 m [ft] apart at the 
GC955 site and 250 m [ft] at the WR313 site) relative to the 160 dB 
distance (670 m [ft]). Thus, the area including overlap is 6.5 times 
the area excluding overlap at GC955 and 5.3 times the area excluding 
overlap at WR313, so a marine mammal that stayed in the survey areas 
during the entire survey could be exposed approximately 6 or 7 times, 
on average. Some degree of re-exposure may occur due to re-exposure of 
the same area along designated tracklines; however, it is unlikely to 
assume that a particular animal would not move within their environment 
and stay in the area during the entire survey. NMFS assumes that 
individuals will move away if they experience sound levels high enough 
to cause significant stress or functional impairment.
    For marine mammals in the IHA (including those listed under the 
ESA, such as sperm whales), exposures are often equated to take and are 
assessed in a quantitative method, however, take does not necessarily 
mean an exposure to a specific threshold. In the Biological Opinion 
conducted under the ESA, exposure analyses identify species that are 
likely to co-occur with the specified activity's effects on the 
environment in space and time, and identify the nature of that co-
occurrence. The exposure analysis identifies, as possible, the number, 
age or life stage, and gender of the individuals likely to be exposed 
to the action's effects and the population(s) or subpopulation(s) those 
individuals represent. See the ``Estimated Take by Incidental 
Harassment'' section below to see how USGS and NMFS calculated take for 
this IHA. NMFS applies certain acoustic thresholds to help determine at 
what point during exposure to seismic airguns marine mammals may be 
``harassed,'' and these thresholds help to develop buffer and exclusion 
zones around the sound source. Pending better information, NMFS 
believes the data and methodology represent the best available 
information and methods to evaluate exposure and take to the marine 
mammal species in the action area of the specified activity.
    Comment 14: The Industry Associations states that the USGS IHA 
application and associated EA would have been improved by the inclusion 
of more recent scientific information. The application, for example, 
makes extensive reference to Richardson et al. (1995) and Richardson et 
al. (1999). It should have also included more recent science indicating 
that avoidance responses are likely both minor and unrelated to sound 
levels (Richardson et al., 2011; Southall, 2010; and Ellison, 2012). 
This would have facilitated a more accurate risk assessment and would 
have more clearly noted that the detailed statistical analyses needed 
to validate conjecture regarding subtle changes in direction are simply 
not available.
    Response: NMFS acknowledges that behavioral responses are complex 
and influenced by a variety of factors, including species, behavioral 
context, source characteristics, and prior experience and agrees with 
current science indicating this. All these factors are important in 
determining the likelihood of an animal exhibiting an avoidance 
response. In the severity index provided in Ellison et al. (2012), 
avoidance responses are given a severity score of 6 or higher, which 
indicates a higher-level response (i.e., those that score between 5 and 
9 on the severity index). Ellison et al. (2012) states that higher-
level response are best described by a dose-response relationship, 
which directly relates to received sound level (opposed to lower-level 
responses that correspond more closely to the context of exposure). 
Nevertheless, NMFS agrees that context of exposure is an important 
factor for consideration for all behavioral responses and is considered 
within the overall assessment qualitatively, since it cannot yet be 
formally incorporated into quantitative acoustic criteria.
    Comment 15: The Industry Associations state that it does not appear 
that frequency weighting was adequately considered in assessing Level B 
(behavioral) effects. It is well documented that dolphins are mid-
frequency hearing specialists. The seismic source, as described in the 
IHA application, has ``dominant frequency components <500 Hz'' and the 
105 in\3\ GI airgun source has dominant frequency components 0 to 188 
Hz. There is little overlap in dolphins' nominal hearing range (150 Hz 
to 160 kHz; Southall et al., 2007), and the dominant frequency 
components of the seismic sources. Failure to incorporate frequency 
weighting likely results in overestimating dolphin incidental takes by 
at least a factor of two.
    Response: Frequency weighting takes into account that all marine 
mammal species do not have identical hearing capabilities. To reflect 
this, Southall et al. (2007) proposed that marine mammals divided into 
five functional hearing groups and subsequently recommended frequency 
weighting functions for each of these groups. NMFS agrees that taking 
into account frequencies that marine mammals hear is an important 
consideration. For example, if a sound is entirely outside the hearing 
range of a species, it is not considered to have the potential to cause 
a significant response.
    There are data to indicate that frequency weighting is an important 
consideration associated with noise-induced hearing loss (Finneran and 
Schlundt, 2009; Finneran and Schlundt, 2011). For behavior, the 
relationship between severity of response and frequency weighting is 
less clear and does not necessarily correspond to the severity of 
behavioral response expected (e.g., individuals have been shown to 
behaviorally respond to sounds that are on the edge of their hearing 
range, where they cannot hear sound as well). Behavioral effects are 
more challenging to predict since they often involve other variables 
beyond detection (e.g., perception and cognition, contextual cues, and 
previous experience). Despite most of the acoustic energy from seismic 
activities occurring outside the best hearing range of odontocetes, 
there are data showing that these species do behaviorally respond to 
these types of activities. For example, Miller et al. (2005) reported 
that belugas responded (avoidance) to seismic activity by 10 to 20 km 
(5.4 to 10.8 nmi). Thus, frequency weighting does not appear to be an 
accurate way to predict the potential of an animal to behavioral 
respond to a sound.
    Comment 16: The Industry Associations state that there is mounting 
scientific evidence that behavioral reactions are species-dependent 
(Stone and Tasker, 2006) and can vary due to biological and 
environmental context (Wartzok et al., 2004; Frost et al., 1984; Finley 
et al., 1990; Richardson et al., 2011; Miller et al., 2005; and 
Richardson et al., 1999).
    Response: In the notice of the proposed IHA (78 FR 11821, February 
20, 2013), NMFS agrees that ``behavioral responses to stimuli are 
complex and influenced to varying degrees by a number of factors, such 
as species, behavioral contexts, geographical regions, source 
characteristics (moving

[[Page 33377]]

or stationary, speed, direction, etc.), prior experience of the animal 
and physical status of the animal.'' NMFS's current acoustic criteria 
are based on the best available science, which does not typically allow 
for one to develop species-specific criteria. Instead, species, as far 
as acoustic criteria, must be considered within larger overall marine 
mammal groups. Species-specific or context-dependent considerations are 
considered within larger overall marine mammal groups. Species-specific 
or context-dependent considerations are considered within the overall 
assessment qualitatively, since they cannot yet be formally 
incorporated into quantitative acoustic criteria.
    Comment 17: The Industry Associations states that bow-riding 
dolphins are an excellent example of a normal behavioral pattern and 
should not be assessed as a take based on received sound levels, using 
any metric. This behavior has been commonly observed on seismic and 
other vessels, challenging assertions of harm to the animals. The fact 
that various marine mammals want to approach and enter the ensonified 
area raises serious questions about the basic validity of a regulatory 
approach that rigidly established proximity to sound as its basis. The 
proposed shut-down requirement for dolphins, which frequently bowride 
vessels, is not warranted.
    The USGS IHA prescribes mitigation zones and requires shut-downs 
for all marine mammals, including dolphins, entering the defined 190/
180/160 dB (rms) ensonified area. Scientific research on the hearing of 
delphinids and hearing control plus decades of studies and field 
observations of dolphins interacting with seismic vessels fail to 
support a conclusion that sound from seismic surveys injure these 
animals. The biology of dolphin hearing, hearing control mechanisms, 
and dolphin behavior involving bow-riding should have been more fully 
considered in the IHA request and environmental risk analyses of the 
EA. Failure to adequately consider these factors results in 
overestimating the risk of seismic surveys to bow-riding dolphins. The 
EA fails to present the environmental assessment sufficient to justify 
the need for shut-downs. This faulty risk assessment is then used to 
support the new and unwarranted dolphin shut-down requirement. The 
proposal is operationally disruptive, potentially to a level of making 
such surveys impossible to conduct. The requirement conflicts with 
longstanding mitigation methods for seismic surveys in the GOM as well 
as proposed mitigation measures. Based on the information detailed in 
the Industry Associations letter, they strongly recommend that NMFS and 
USGS do not require shut-down of the seismic sources for dolphins 
entering the exclusion zone.
    Response: USGS has proposed the buffer and exclusion zones included 
in the IHA in their IHA application and EA. Also, USGS has proposed to 
implement the monitoring and mitigation measures included in the IHA in 
their IHA application and EA. They have determined that the measures 
are effective and practicable as described in this Federal Register 
notice, and NMFS concurs with their determination. As a precautionary 
approach, USGS has included dolphins and whales in the shut-down 
procedures as a mitigation measure, which has been standard for other 
seismic surveys conducted for the purpose of scientific research and 
that have occurred worldwide.
    The shut-down procedure for dolphins is not a ``new and 
unwarranted'' requirement, it has been proposed by USGS and NSF (and 
required by NMFS in IHAs) on numerous seismic surveys that have 
occurred around the world since at least 2003.
    Comment 18: The Industry Associations states that it has been long 
recognized that cetaceans emit sounds as they echolocate that are well 
above the regulatory protective levels of 180/160 dB 1 [mu]Pa (rms). 
Repeated dolphin clicks have been measured up to 230 dB (Au et al., 
1978). Dr. Alexander Supin and Dr. Paul Nachtigall developed a way of 
measuring the hearing of cetaceans during echolocation by examining the 
brain wave patterns of the animals to both the outgoing echolocation 
signal and the echo that returned from that signal (Supin et al., 2003; 
Nachtigall and Supin, 2008). Research on harbor porpoise (Linnenschmidt 
et al., 2012) and the bottlenose dolphin (Li et al., 2011; 2012) 
suggest hearing control may apply to a number of different species of 
echolocating whales and dolphins. The EA should consider this new 
research regarding the potential hearing control mechanisms of 
odontocetes. There are indications that some cetaceans naturally reduce 
their hearing sensitivity and therefore the estimates of incidental 
takes should be reduced.
    Response: Many mammals, especially those that echolocate (i.e., 
bats), exhibit a vocally-induced acoustic reflex of the middle ear 
muscles (i.e., stapedius reflex). This reflex acts as a protective 
mechanism to protect the ear from damage from loud sounds. This reflex 
depends on a multitude of factors, including sound pressure level and 
frequency. It is not surprising that marine mammals are able to control 
their hearing while echolocating. Whether this phenomenon in marine 
mammals is associated with the stapedius reflex or another mechanism is 
uncertain. What also remains unclear is whether these animals are 
capable of adjusting their hearing when exposed to sources other than 
their own vocalizations (which they know are about to occur) and 
specifically the acoustic characteristics associated with seismic 
activities. Last, considering the amount of anthropogenic sound present 
in the marine environment, using this reflex in association with it 
would likely reduce their ability to hear important environmental and 
biological cues.
    Comment 19: The Industry Associations state that recent work by Dr. 
Jim Finneran investigated the auditory effects on bottlenose dolphins 
exposed to multiple underwater impulses produced by a seismic airgun. 
The pre- and post-exposure hearing thresholds in exposed dolphins were 
compared to determine the amount of temporary hearing loss, called a 
temporary threshold shift (TTS), as a function of exposure level and 
the number of impulses. The dolphins exposed to seismic sound levels up 
to 196 dB re 1 [mu]Pa\2\s (cumulative SEL) showed no measurable TTS 
(Finneran et al., 2012; Finneran et al., 2011). The USGS EA would be 
improved by a discussion of this research regarding animal sound 
tolerance. These results would further explain why dolphins may bow-
ride seismic vessels without sustaining injury.
    Response: NMFS believes that these documents are adequate and 
contain a proper description of risk assessment in order for it to make 
the necessary determinations under the MMPA and issue the IHA. USGS has 
proposed the buffer and exclusion zones included in the IHA in their 
IHA application and EA. As a precautionary approach, USGS has included 
dolphins and whales in the shut-down procedures as a mitigation 
measure. Also, USGS has proposed to implement the monitoring and 
mitigation measures included in the IHA in their IHA application and 
EA. They have determined that the measures are effective and 
practicable as described in this Federal Register notice, and NMFS 
concurs with their determination. USGS included a discussion of 
tolerance in the section on the ``Potential Effects of Airguns Sounds 
on Marine Mammals'' in the EA as well

[[Page 33378]]

as the IHA application. No Level A harassment, serious injury, or 
mortality is expected or has been authorized.
    Comment 20: The Industry Associations state that the USGS EA should 
have considered extensive peer-reviewed literature and field 
observations that establish that bow-riding is normal, not abnormal, 
behavior for dolphins. Also, Northern bottlenose whales (Hyperoodon 
ampullatus) are sometimes quite tolerant of slow-moving vessels (Reeves 
et al., 1993; Hooker et al., 2001); dolphins may tolerate boats of all 
sizes, often approaching and riding the bow and stern waves (Shane et 
al., 1986); and spinner dolphins in the GOM were observed bow-riding 
the survey vessel in all 14 sightings of this species during one survey 
(Wursig et al., 1998).
    Response: NMFS believes that these documents are adequate and 
contain a proper description of risk assessment in order for it to make 
the necessary determinations under the MMPA and issue the IHA. NMFS 
states in the notice of the proposed IHA (78 FR 11821, February 20, 
2013) that ``seismic operators and PSOs on seismic vessels regularly 
see dolphins and other small toothed whales near operating airgun 
arrays, but in general there is a tendency for most delphinids to show 
some avoidance of operating seismic vessels (e.g., Goold, 1996a,b,c; 
Calambokidis and Osmek, 1998; Stone, 2003; Moulton and Miller, 2005; 
Holst et al., 2006; Stone and Tasker, 2006; Weir, 2008; Richardson et 
al., 2009; Barkaszi et al., 2009; Moulton and Holst, 2010). Some 
dolphins seem to be attracted to the seismic vessel and floats, and 
some ride the bow wave of the seismic vessel even when large arrays of 
airguns are firing (e.g., Moulton and Miller, 2005). Nonetheless, small 
toothed whales more often tend to head away, or to maintain a somewhat 
greater distance from the vessel, when a large array of airguns is 
operating than when it is silent (e.g., Stone and Tasker, 2006; Weir, 
2008; Barry et al., 2010; Moulton and Holst, 2010). In most cases, the 
avoidance radii for delphinids appear to be small, on the order of one 
km or less, and some individuals show no apparent avoidance.''
    Comment 21: The Industry Associations state that proposed 
mitigation measures conflict with existing requirements. In the U.S. 
GOM, the requirement to shut-down seismic sources if an animal enters 
the exclusion zone has historically been applied to whales, but not 
dolphins. The Bureau of Ocean Energy Management (BOEM) and Bureau of 
Safety and Environmental Enforcement's (BSEE) existing mitigation 
requirements are documented in JOINT NTL No. 2012-G02 ``Notice to 
Lessees and Operators of Federal Oil, Gas, and Sulphur Leases in the 
OCS, Gulf of Mexico OCS Region--Implementation of Seismic Survey 
Mitigation Measures and Protected Species Observer Program,'' which can 
be found online at: https://www.boem.gov/Regulations/Notices-To-Lessees/Notices-to-Lessees-and-Operators.aspx. The USGS monitoring/shut-down 
zones should be consistent with these existing mitigation measures 
which have been proven protective. The existing standard is premised 
upon a 2002 NMFS Biological Opinion. BOEM has itself previously 
recognized in its recent Supplemental EA for a specific seismic permit 
in the GOM that extending the shut-down requirement to delphinids is 
unwarranted.
    Response: USGS has proposed the buffer and exclusion zones included 
in the IHA in their IHA application and EA. As a precautionary 
approach, USGS has included dolphins and whales in the shut-down 
procedures as a mitigation measure. USGS states that if a marine mammal 
is detected outside the exclusion zone, but is likely to enter the 
exclusion zone, and if the vessel's speed and/or course cannot be 
changed to avoid having the 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. For USGS's specified activity, NMFS has included this 
mitigation measure in the IHA. Under the MMPA, NMFS (not BOEM) 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; therefore, it has included the shut-
down for whales and dolphins as a mitigation measure in the IHA. NMFS 
will enter into further future discussions with BOEM, BSEE, the 
Industry Associations, and other parties as to whether certain 
monitoring and mitigation measures are practicable from an economic, 
safety, and/or operational standpoint as part of BOEM's request to NMFS 
for incidental take regulations under the MMPA for oil and gas-related 
seismic surveys on the outer continental shelf of the GOM.
    Comment 22: The Industry Associations state that the proposed USGS 
requirement to shut-down for all marine mammals entering the exclusion 
zone conflicts with discretionary shut-downs contemplated in BOEM's 
``Atlantic Geological and Geophysical (G&G) Activities Programmatic 
Environmental Impact Statement'' (Atlantic G&G PEIS). In the Atlantic 
G&G draft PEIS proposal, shut-downs would not be required for dolphins 
approaching the vessel or towed equipment at a speed and vector that 
indicates voluntary approach to bow-ride or chase towed equipment (this 
proposed mitigation measures is also unwarranted). If a dolphin 
voluntarily moves into the exclusion zone after acoustic sound sources 
are operating, it is reasoned that the sound pressure level is not 
negatively affecting that particular animal.
    The Industry Associations state that dolphin shut-downs would be 
operationally disruptive. Seismic operators report that dolphins 
frequently approach and chase equipment towed in the water behind the 
vessel. Therefore, requiring a shut-down for dolphins could 
significantly increase survey duration or even make it impossible to 
conduct some high-resolution surveys.
    Response: USGS has proposed the buffer and exclusion zones included 
in the IHA in their IHA application and EA. As a precautionary 
approach, USGS has included dolphins and whales in the shut-down 
procedures as a mitigation measure. Also, USGS has proposed to 
implement the monitoring and mitigation measures included in the IHA in 
their IHA application and EA. They have determined that the measures 
are effective and practicable as described in this Federal Register 
notice, and NMFS concurs with their determination.
    NMFS will enter into further future discussions with BOEM, BSEE, 
the Industry Associations, and other parties as to whether certain 
monitoring and mitigation measures are practicable from an economic, 
safety, and/or operational standpoint as part of Industry's request to 
NMFS for IHAs under the MMPA for oil and gas-related seismic surveys on 
the outer continental shelf of the Atlantic Ocean.
    Comment 23: CBD states that if NMFS intends to allow harassment of 
marine mammal for this activity, the IHA and supporting environmental 
analyses under the NEPA must be revised and reissued as a draft for 
further public review and comment.
    Response: NMFS disagrees with the CBD's statement. USGS has revised 
its EA made it available online on its environmental compliance Web 
site at: https://woodshole.er.usgs.gov/project-pages/environmental_compliance/.

[[Page 33379]]

    Comment 24: CBD states that NMFS is violating its duty under NEPA 
to take a hard look at the impact of its decision to allow incidental 
harassment of marine mammals generally failing to analyze cumulative 
impacts of human activity on the habitat and wildlife in the GOM. The 
NEPA analysis must quantitatively evaluate the impacts of military 
activities, fisheries, the Deepwater Horizon disaster, and the ongoing 
Unusual Mortality Event (UME) declared for cetaceans in the northern 
GOM beginning February 1, 2010. In the absence of such analysis, the 
Finding of No Significant Impact (FONSI) is arbitrary. Without knowing 
the extent of the harm done to the GOM ecosystem, NMFS should proceed 
with utmost caution before authorizing additional disruptive 
activities. Not quantitatively analyzing cumulative impacts prevents 
the public from understanding whether the incremental harm that this 
survey inflicts has significant impacts on an already injured ecosystem 
that could restrict other uses like fishing.
    Response: NMFS disagrees with the CBD's statement. Cumulative 
effects are defined as ``the impact on the environment which results 
from the incremental impact on the action when added to other past, 
present, and reasonably foreseeable future actions regardless of what 
agency (Federal or non-Federal) or person undertakes such other 
actions'' (40 CFR 1508.7). Cumulative impacts can result from 
individually minor but collectively significant actions that take place 
over a period of time. While the EA did not contain a quantitative 
analysis, USGS's EA had a comprehensive discussion of ongoing and 
reasonably foreseeable actions in the GOM that included: Ongoing oil 
and gas exploration, development, and production; existing oil and gas 
infrastructure; commercial fishing; alternate energy development; 
military operations; marine vessel traffic; scientific research; 
recreation and tourism; acoustic masking; and marine mining and 
disposal areas. These activities account for cumulative impacts to 
regional and worldwide populations of marine mammals, many of whom are 
a small fraction of their former abundance and are listed as endangered 
or threatened under the ESA and depleted under the MMPA.
    Despite these regional and global anthropogenic and natural 
pressures, available trend information indicates that most local 
populations of marine mammals in the GOM are stable or increasing 
(Waring et al., 2013). Most importantly, this seismic survey uses a 
small airgun array configuration and would be limited to a small area 
for a relatively short period of time, the inclusion of the monitoring 
and reporting measures and the requirement to implement mitigation 
measures (e.g., shut-down of seismic operations), will reduce the 
amount and severity of the potential impacts; therefore, it is expected 
to have a negligible impact on the species or stocks of marine mammals 
in the action area.
    The results of the cumulative impacts analysis in the NSF/USGS PEIS 
indicated that there would not be any significant cumulative effects to 
marine resources from the proposed NSF-funded or USGS marine seismic 
research. That same section of the NSF/USGS PEIS also stated that, ``a 
more detailed, cruise-specific cumulative effects analysis would be 
conducted at the time of the preparation of the cruise-specific EAs, 
allowing for the identification of other potential activities in the 
area of the proposed seismic survey that may result in cumulative 
impacts to environmental resources.'' USGS's cruise-specific EA for the 
low-energy seismic survey, ``it appears that there is little overlap 
between the seismic survey and other activities, and little chance of 
significant cumulative effects * * * low-energy airgun operations are 
unlikely to cause any large-scale or prolonged effects in marine 
mammals, and the duration of the surveys is very short (i.e., 96 hours 
at each site).''
    Comment 25: The CBD states that the EA fails to mention the 
lingering effects on habitat and wildlife in the GOM from the Deepwater 
Horizon oil spill. Without knowing the extent of the harm done to the 
GOM ecosystem, NMFS should proceed with utmost caution before 
authorizing additional disruptive activities. Not quantitatively 
analyzing cumulative impacts prevents the public from understanding 
whether the incremental harm that this survey inflicts has significant 
impacts on an already injured ecosystem that could restrict other uses 
like fishing.
    Response: NMFS disagrees with the CBD's statement. While the EA did 
not contain a quantitative analysis, USGS's EA had a qualitative 
analysis and comprehensive discussion of ongoing and reasonably 
foreseeable actions in the GOM that included: Ongoing oil and gas 
exploration, development, and production; existing oil and gas 
infrastructure; commercial fishing; alternate energy development; 
military operations; marine vessel traffic; scientific research; 
recreation and tourism; and marine mining and disposal areas.
    Comment 26: The CBD states that NMFS's IHA does not rely on the 
best available science regarding marine mammal impact thresholds, 
including the 160 dB (rms) Level B harassment threshold (i.e., buffer 
zone) and the 180 dB (rms) Level A harassment threshold (i.e., 
exclusion zone). Further, even if NMFS's assumptions regarding impact 
thresholds were correct, the IHA authorizes the take of more than small 
numbers of marine mammals and greater than negligible impacts on 
species and stocks, rendering the IHA as proposed illegal under the 
MMPA.
    Response: NMFS has established 160 dB (rms) as the criterion for 
potential Level B harassment for impulse noise for marine mammals and 
180 dB (rms) and 190 dB (rms) as the criterion for potential Level A 
harassment for impulse noise for cetaceans (i.e., whales, dolphins, and 
porpoises) and pinnipeds (i.e., seals and sea lions), respectively. 
NMFS is currently developing new acoustic guidelines for assessing the 
effects of anthropogenic sound on marine mammal species under our 
jurisdiction. The updated acoustic criteria will be based on recent 
advances in science. More information regarding NMFS's marine mammal 
acoustic guidelines can be found online at: https://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm. NMFS has determined, provided that the 
aforementioned mitigation and monitoring measures are implemented, that 
the impact of conducting a marine seismic survey in the deep water of 
the Gulf of Mexico, April to May 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 (see Table 3 below for authorized take numbers).
    Comment 27: The CBD requests that NMFS make all of the information 
regarding the contents of an EFH assessment and EFH consultation 
(including EFH conservation recommendations), available to the public 
along with the revised NEPA analysis prior to publishing a final rule 
authorizing the activity.
    Response: USGS has made a no effect determination regarding impacts 
on EFH. NMFS, Office of Protected Resources, Permits and Conservation 
Division has determined that the issuance of an IHA for the taking of 
marine mammals incidental to a low-energy marine seismic survey in the 
GOM will not have an adverse impact on EFH; therefore, an EFH 
consultation is not required.
    Comment 28: The CBD states that NMFS's IHA does not rely on the 
best available science regarding thresholds for marine mammal impacts, 
including

[[Page 33380]]

the 160 dB (rms) threshold and the 180/190 dB (rms) Level A harassment 
(exclusion zone) threshold. Five of the world's leading biologists and 
bioacousticians working in this field recently characterized the 160 dB 
threshold as ``overly simplified, scientifically outdated, and 
artificially rigid'' and therefore NMFS must use a more conservative 
threshold. Using a single sound pressure level of 160 dB for Level B 
harassment represents a major step backward from recent programmatic 
authorizations. For Navy sonar activity, NMFS has incorporated into its 
analysis linear risk functions that endeavor to take account of risk 
and individual variability and to reflect the potential for take at 
relatively low levels. If NMFS were to modify its threshold estimates, 
as it must be based on the best available science, the estimated number 
of marine mammal takes incidental to the proposed seismic survey would 
be significantly higher than NMFS's current estimates. Further, even if 
NMFS's assumptions regarding impact thresholds were correct, the IHA 
authorizes the take of more than small numbers of marine mammals and 
greater than negligible impacts on species and stocks, rendering the 
IHA as proposed illegal under the MMPA.
    Response: NMFS has established 180 dB (rms) and 190 dB (rms) as the 
criterion for potential Level A harassment for impulse noise for 
cetaceans (i.e., whales, dolphins, and porpoises) and pinnipeds (i.e., 
seals and sea lions), respectively, which were conservatively derived 
to encompass levels associated with temporary threshold shifts (TTS) 
and not permanent threshold shifts (PTS). NMFS's is currently 
developing new acoustic guidelines for assessing the effects of 
anthropogenic sound on marine mammal species under our jurisdiction. 
The updated acoustic criteria will be based on recent advances in 
science. NMFS is working toward establishing Level B harassment 
criteria that better account for the variability and complexity of 
behavioral responses associated with noise exposure (e.g., moving away 
from a step function towards exposure-response functions that accounts 
for risk varying with received level. More information regarding NMFS's 
marine mammal acoustic guidelines can be found online at: https://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm. NMFS has determined, 
provided that the aforementioned mitigation and monitoring measures are 
implemented, that the impact of conducting a marine seismic survey in 
the deep water of the Gulf of Mexico, April to May 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 (see Table 3 below for authorized take 
numbers).
    Comment 29: The CBD states that NMFS's use of the 180/190 dB (rms) 
threshold for Level A harassment ignores the best available science and 
is inadequate. NMFS cannot assume that TTS, and even PTS would be 
unlikely for marine mammals that enter the exclusion zone. A number of 
recent studies indicate that anthropogenic sound can induce PTS at 
lower levels than anticipated. New data indicate that mid-frequency 
cetaceans have greater sensitivity to sounds within their best hearing 
range than was previously thought. This recent research indicates it is 
possible that marine mammals will experience injury, or potentially 
serious injury, at lower sound thresholds than NMFS assumes. NMFS must 
take into account the best available science and set lower thresholds 
for Level A harassment, which would lead to larger exclusion zones 
around the survey. Given NMFS's lax approach to estimating impact 
thresholds for injury to marine mammals from the proposed survey, it is 
likely that many more marine mammals will be harmed than NMFS 
estimates. In light of the best available science, NMFS cannot 
rationally defend its conclusion that the proposed survey will harm no 
more than small numbers of marine mammals and will have no more than 
negligible impacts on those species or stocks.
    Response: NMFS has established 180 dB (rms) and 190 dB (rms) as the 
criterion for potential Level A harassment for impulse noise for 
cetaceans (i.e., whales, dolphins, and porpoises) and pinnipeds (i.e., 
seals and sea lions), respectively, which were conservatively based on 
TTS. NMFS's is currently developing new acoustic guidelines for 
assessing the effects of anthropogenic sound on marine mammal species 
under our jurisdiction. The updated acoustic criteria will be based on 
recent advances in science and includes studies that take into account 
frequency sensitivity associated with noise-induced hearing loss. 
Nevertheless, since these original criteria (i.e., 180/190 dB [rms]) 
were based on TTS, in the majority of situations, especially for 
intermittent sources, like airguns, the ranges of exclusion zones that 
account for these new data are equal, if not smaller than the zones 
based on the 180 and 190 dB (rms) thresholds. Thus, the exclusion zones 
to 180 and 190 dB are expected to be protective. More information 
regarding NMFS's marine mammal acoustic guidelines can be found online 
at: https://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
    NMFS has determined, provided that the aforementioned mitigation 
and monitoring measures are implemented, that the impact of conducting 
a marine seismic survey in the deep water of the Gulf of Mexico, April 
to May 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 (see Table 3 below 
for authorized take numbers). 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.
    Comment 30: The CBD states that NMFS has blatantly disregarded the 
MMPA's prohibition on allowing the take of more than small numbers of 
marine mammals. For example, NMFS estimates that in eight days, 118 
melon-headed whales will be taken, which is over five percent of the 
population. As noted above, this number is likely an underestimate. But 
even taken at face value, NMFS cannot rationally argue that this is a 
small number. There is no numerical cut-off for ``small numbers.'' NMFS 
does not even attempt to explain how its take estimates meet the 
``small numbers'' requirement. In fact, the IHA entirely disregards 
this statutory requirement. NMFS does not attempt to define small 
numbers, nor does it undertake any sort of analysis of what small 
numbers might be. The Ninth Circuit recently confirmed that the MMPA 
requires that authorizing agencies (here NMFS) to separately find both 
that only small numbers of marine mammals will be taken and that the 
impacts to the species or stock will be negligible. While NMFS 
attempted to rationalize its determination that impacts to the species 
or stocks will be negligible, it undertook no such analysis regarding 
small numbers. The IHA here violates the MMPA because it does not 
guarantee that only small numbers of marine mammals will be taken.
    Response: 50 CFR 216.103 defines ``small numbers'' as ``a portion 
of a marine mammal species or stock whose taking would have a 
negligible impact on that species or stock.'' NMFS has determined, 
provided that the aforementioned mitigation and

[[Page 33381]]

monitoring measures are implemented, that the impact of USGS conducting 
a low-energy marine seismic survey in the deep water of the Gulf of 
Mexico, April to May 2013, may result, at worst, in a temporary 
modification in behavior and/or low-level physiological effects (Level 
B harassment) of small numbers of 18 species of marine mammals (see 
Table 3 below for authorized take numbers and approximate percentage of 
best population estimate of stock). NMFS has determined that the 118 
authorized takes of melon-headed whales is a small number, as it is 
approximately 5.3% of the estimated best population (2,235 animals) in 
the northern GOM stock.
    Comment 31: The CBD states that for the endangered sperm whale, a 
deep-diving whale that feeds in the ocean's ``sound channel,'' take of 
even one individual would constitute more than a negligible impact and 
would therefore violate the MMPA. Reliance on observers for mitigation 
also has limited likelihood of success given the deep-diving behavior 
of sperm whales and the limits of visual observations at night and in 
poor weather. For sperm whales, the take is planned for peak breeding 
season, suggesting that the long-term impacts if reproductive success 
is compromised may be more severe than anticipated.
    Response: 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. No Level A harassment, 
serious injury, or mortality is expected or has been authorized.
    Comment 32: The CBD states that NMFS underestimates the risk of 
entanglement for sperm whales. Even though NMFS acknowledges that this 
``large of an array carries the risk of entanglement for marine 
mammals,'' it completely fails to support the conclusion that large 
whales ``have a low probability of becoming entangled due to slow speed 
of the survey vessel and onboard monitoring efforts.'' In 2008, a 
fishing vessel killed a sperm whale that became entangled in the sea 
anchor (parachute anchor and lines). As the purpose of the sea anchor 
is to drastically slow a vessel (almost stop it), this contradicts the 
proposition that the USGS can reduce sperm whale entanglements by slow 
speed or onboard monitoring efforts (which are limited by low 
visibility at night, when a sperm whale also might not be able to see 
the array).
    Response: In the notice of the proposed IHA (78 FR 11821, February 
20, 2013), NMFS states that the ``. . . proposed seismic survey would 
require towing approximately a single 450 m cable streamer. This large 
of an array carries the risk of entanglement for marine mammals. 
Wildlife, especially slow moving individuals, such as large whales, 
have a low probability of becoming entangled due to slow speed of the 
survey vessel and onboard monitoring efforts. The probability for 
entanglement of marine mammals is considered not significant because of 
the vessel speed and the monitoring efforts onboard the survey 
vessel.'' NMFS has included a requirement in the IHA that PSOs shall 
conduct monitoring while the airgun array and streamer are being 
deployed or recovered from the water. Although the towed hydrophone 
streamers and other towed seismic equipment could come in direct 
contact with marine mammal species, NMFS believes that entanglement is 
highly unlikely due to streamer design and extensive use of this 
equipment (thousands of miles of effort over a many years) without 
entanglement of marine mammals; therefore entanglement is considered 
discountable. No Level A harassment, serious injury, or mortality is 
expected or has been authorized.
    Comment 33: The CBD states that the estimated take exceeds the 
potential biological removal (PBR) level of 1.1 sperm whales. The most 
recent abundance estimate for the sperm whale is 763, from a summer 
2009 oceanic survey covering waters from the 200 m isobaths to the 
seaward extend of the U.S. EEZ. Threats to sperm whales in the GOM are 
numerous. The most recent stock assessment report counts one death from 
entanglement in a fishing vessel's anchor line and seven strandings 
from 2006 to 2010 for which it could not be determined if it was due to 
human interaction. This presents the possibility that mortality from 
human activities is already above the PBR level of 1.1. Any additional 
take of a sperm whale would have greater than negligible impacts on the 
stock because NMFS must take into account the cumulative take of sperm 
whales from other activities.
    Response: The NMFS Draft 2012 Stock Assessment Report for the 
Northern GOM stock of sperm whale has a best abundance estimate of 763 
and a minimum population estimate of 560 individuals. PBR is the 
product of the minimum population size (560), one half the maximum net 
productivity rate (0.04), and a recovery factor (assumed to be 0.1 
because it is an endangered species). PBR for the northern GOM stock of 
sperm whales is 1.1. NMFS has reviewed USGS's EA and IHA application 
and has determined that no more than Level B harassment of marine 
mammals would occur. Any marine mammal that could be exposed to the 
seismic survey would likely experience short-term disturbance. Marine 
mammals are expected, at most, to show an avoidance response to the 
seismic pulses. Further, mitigation measures such as controlled speed, 
course alteration, visual monitoring, and shut-downs when marine 
mammals are detected within defined ranges should further reduce short-
term reactions to disturbance, and minimize any effects on hearing 
sensitivity. No Level A harassment, serious injury, or mortality is 
expected or has been authorized; therefore PBR is not applicable.
    Comment 34: The CBD states that based on multiple factors in NEPA's 
regulations and the controversial nature of the government seismic 
surveys to prospect for novel deepwater fossil fuel sources as well as 
the significant environmental effects of this action requires NMFS to 
prepare a full Environmental Impact Statement (EIS) analyzing the 
impacts of the proposed survey.
    Response: NMFS disagrees with the CBD's comments, NMFS and USGS 
have satisfied all requirements of NEPA. NMFS has adopted USGS's EA and 
prepared a FONSI for this action. NMFS has evaluated USGS's EA and 
found it includes all required components for adoption, these include: 
sufficient evidence and analysis for determining whether to prepare an 
EIS or FONSI; brief discussion of need for the proposed action; a 
listing of alternative to the proposed action; description of the 
affected environment; and brief discussion of the environmental impacts 
of the proposed action and alternatives. NMFS has determined that it is 
not necessary to prepare an EIS for the issuance of an IHA to USGS for 
this activity.
    Comment 35: The CBD states that the EA fails to meet the 
requirement that alternatives ``be given full and meaningful 
consideration'' by dismissing the no action alternative in a cursory 
fashion and failing to consider other alternatives adequately. Other 
alternatives for NMFS to consider include (1) using alternative 
equipment that would reduce the number or length of survey lines; (2) 
selecting alternative sites that are not in EFH and a habitat area of 
particular concern; or (3) conducting more extensive analysis of

[[Page 33382]]

the data collected previously to either eliminate the need for the 
current survey or reduce its size or duration. NMFS cannot support the 
EA and determinations conclusion that the ``no action'' alternative 
would result in the loss of seismic data of considerable scientific 
value because it is possible to collect seismic data without harassing 
marine mammals. In light of this, the USGS and NMFS must analyze 
alternative means of collecting seismic data that lessen impacts to 
wildlife.
    Response: NMFS and USGS have satisfied all requirements of NEPA. 
Given the limited window for the operations and the fact that marine 
mammals are widespread in the survey area throughout the year, altering 
the timing of the proposed project likely would result in no net 
benefits and does not meet the purpose and need of the USGS. Issuing 
the IHA for another period could result in significant delays and 
disruptions to the cruise as well as subsequent studies on the Pelican 
for 2013 and beyond. NMFS has fully complied with its obligations under 
NEPA.
    Comment 36: Several private citizens oppose the issuance of an IHA 
to USGS for the take of marine mammals incidental to conducting a low-
energy seismic survey in deep water of the northwest Gulf of Mexico 
from April to May 2013. They state that the airguns will emit decibels 
at 190 to 230 for 96 hours in two different locations, and can cause 
hearing damage, bleeding of the brain, behavioral issues, and 
strandings. Marine mammals depend on their sensitive hearing for 
survival. Hearing loss for a cetacean can mean the inability to 
function, hunt, navigate, and cause death. They state that it has been 
widely documented that the use of active sonar, underwater detonations, 
and other extremely loud noises terrorizes and often kills cetaceans. 
Marine life is already threatened from oil spills, drilling, pollution, 
hunting, ship strikes, over-fishing, climate change, etc. Species, such 
as the North Atlantic, humpback, sei, fin, blue, and sperm whale and 
West Indian manatee, are listed as endangered under the ESA. Using 
lookouts (i.e., PSOs) to detect marine life during this seismic survey 
is unacceptable as they can only see the surface of the ocean, and the 
marine mammals spend most of their lives underwater. Alternative 
technologies and methods should be used so that these activities have 
less potential impacts. They request a public hearing be held before 
the Commission.
    Response: NMFS recognizes that numerous private citizens oppose the 
issuance of an IHA to USGS for the low-energy marine seismic survey in 
the deep water of the GOM. The notice of the proposed IHA (78 FR 11821, 
February 20, 2013) included a discussion of the effects of sounds from 
airguns and Navy sonar on mysticetes and odontocetes including 
tolerance, masking, behavioral disturbance, hearing impairment, other 
non-auditory physical effects and strandings. In April 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, which included sperm whales, and included an 
Incidental Take Statement (ITS) incorporating the requirements of the 
IHA as Terms and Conditions of the ITS is likewise a mandatory 
requirement of the IHA. The West Indian manatee is managed under the 
jurisdiction of the U.S. Fish and Wildlife Service (USFWS) and is not 
expected to occur in the action area. On February 25 to 27, 2013, the 
BOEM held a workshop on the status of alternative and quieting 
technologies entitled ``Quieting Technologies for Reducing Noise during 
Seismic Surveying and Pile Driving'' that examined current and emerging 
technologies that have the potential to reduce the impacts of noise 
generated during offshore exploratory seismic surveys, pile driving, 
and vessels associated with these activities. NMFS will work with other 
Federal agencies to identify, evaluate, and potentially develop these 
alternative and quieting technologies for potential future use. During 
the 30-day public comment period, NMFS forwarded copies of the IHA 
application to the Commission and its Committee of Scientific Advisors 
and received comments on March 12, 2013. NMFS does not expect to hold a 
public hearing before the Commission.
    Comment 37: A private citizen recommends:
    (1) The installation of a passive acoustic monitoring (PAM) system 
to detect any vocalizations by whales or dolphins, and to help PSOs 
locate any that may be present at night;
    (2) Additional PSOs be added to the ship; and
    (3) An additional support vessel should be provided to steam in 
front of the survey vessel to spot any whales or dolphins prior to the 
larger vessel approaching.
    Response: The NSF/USGS PEIS states that a towed PAM system is used 
normally for high-energy seismic surveys, and implied that it was not 
used for low-energy seismic surveys since towing PAM equipment is not 
practicable in some cases. USGS's project is considered a low-energy 
marine seismic survey; therefore, USGS has determined that it is not 
practicable and a towed PAM system will not be used for this specific 
project. USGS has appointed two PSOs onboard the Pelican, with NMFS's 
concurrence, to monitor and mitigate the buffer and exclusion zones 
during daylight. The Pelican is relatively small; therefore, the 
available berths for additional PSOs are limited. In addition to the 
PSOs, at least two of the USGS personnel aboard the vessel will have 
PSO training to detect protected species and will be available to cover 
for PSOs during mealtimes and restroom breaks, if needed. Also, the 
vessel's crew will be instructed to observe from the bridge and decks 
for opportunistic sightings. In certain situations, NMFS has 
recommended the use of additional support vessels to enhance PSO 
monitoring effort during seismic surveys. For this and other similar 
low-energy seismic surveys, however, NMFS has not deemed it necessary 
to employ additional support vessels to monitor the buffer and 
exclusion zones due to the relatively small distances of these zones. 
An additional vessel would unnecessarily increase noise and emissions 
in the action area as well.

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

    The marine mammal species that potentially occur within the GOM 
include 28 species of cetaceans and one sirenian (Jefferson and Schiro, 
1997; Wursig et al., 2000; see Table 2 below). In addition to the 28 
species known to occur in the GOM, the long-finned pilot whale 
(Globicephala melas), long-beaked common dolphin (Delphinus capensis), 
and short-beaked common dolphin (Delphinus delphis) could potentially 
occur there. However, there are no confirmed sightings of these species 
in the GOM, but they have been seen close and could eventually be found 
there (Wursig et al., 2000). Those three species are not considered 
further in this document. The marine mammals that generally occur in 
the action area belong to three taxonomic groups: mysticetes (baleen 
whales), odontocetes (toothed whales), and sirenians (the West Indian 
manatee). Of the marine mammal species that potentially occur within 
the GOM, 21 species of cetaceans (20 odontocetes, 1 mysticete) are 
routinely present and have been included in the analysis for incidental 
take to the seismic survey. 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 North Atlantic right

[[Page 33383]]

(Eubalaena glacialis), humpback (Megaptera novaeangliae), sei 
(Balaenoptera borealis), fin (Balaenoptera physalus), blue 
(Balaenoptera musculus), and sperm (Physeter macrocephalus) whale, as 
well as the West Indian (Florida) manatee (Trichechus manatus 
latirostris). Of those endangered species, only the sperm whale is 
likely to be encountered in the survey area. No species of pinnipeds 
are known to occur regularly in the GOM, and any pinniped sighted in 
the study area would be considered extralimital. The Caribbean monk 
seal (Monachus tropicalis) used to inhabit the GOM but is considered 
extinct and has been delisted from the ESA. The West Indian manatee 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.
    In general, cetaceans in the GOM appear to be partitioned by 
habitat preferences likely related to prey distribution (Baumgartner et 
al., 2001). Most species in the northern GOM concentrated along the 
upper continental slope in or near areas of cyclonic circulation in 
waters 200 to 1,000 m (656.2 to 3,280.8 ft) deep. Species sighted 
regularly in these waters include Risso's, rough-toothed, spinner, 
striped, pantropical spotted, and Clymene dolphins, as well as short-
finned pilot, pygmy and dwarf sperm, sperm, Mesoplodon beaked, and 
unidentified beaked whales (Davis et al., 1998). In contrast, 
continental shelf waters (< 200 m deep) are primarily inhabited by two 
species: bottlenose and Atlantic spotted dolphins (Davis et al., 2000, 
2002; Mullin and Fulling, 2004). Bottlenose dolphins are also found in 
deeper waters (Baumgartner et al., 2001). The narrow continental shelf 
south of the Mississippi River delta (20 km [10.8 nmi] wide at its 
narrowest point) appears to be an important habitat for several 
cetacean species (Baumgartner et al., 2001; Davis et al., 2002). There 
appears to be a resident population of sperm whales within 100 km (54 
nmi) of the Mississippi River delta (Davis et al., 2002).
    Table 2 (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 April to May 2013.

  Table 2--The Habitat, Regional Abundance, and Conservation Status of Marine Mammals That May Occur in or Near
                         the Seismic Survey Area in the Deep Water of the Northwest GOM
                        [See text and Table 2 in USGS's application for further details]
----------------------------------------------------------------------------------------------------------------
                                                      Population
            Species                  Habitat         estimate \3\    ESA \1\      MMPA \2\      Population trend
                                                       (minimum)                                       \3\
----------------------------------------------------------------------------------------------------------------
                                                   Mysticetes
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale      Coastal and shelf  Extralimital....  EN.....  D...............  Increasing.
 (Eubalaena glacialis).
Humpback whale (Megaptera       Pelagic,           Rare............  EN.....  D...............  Increasing.
 novaeangliae).                  nearshore
                                 waters, and
                                 banks.
Minke whale (Balaenoptera       Pelagic and        Rare............  NL.....  NC..............  No information
 acutorostrata).                 coastal.                                                        available.
Bryde's whale (Balaenoptera     Pelagic and        33 (16)--         NL.....  NC..............  Unable to
 brydei).                        coastal.           Northern GOM                                 determine.
                                                    stock.
Sei whale (Balaenoptera         Primarily          Rare............  EN.....  D...............  Unable to
 borealis).                      offshore,                                                       determine.
                                 pelagic.
Fin whale (Balaenoptera         Continental        Rare............  EN.....  D...............  Unable to
 physalus).                      slope, pelagic.                                                 determine.
Blue whale (Balaenoptera        Pelagic, shelf,    Extralimital....  EN.....  D...............  Unable to
 musculus).                      coastal.                                                        determine
----------------------------------------------------------------------------------------------------------------
                                                   Odontocetes
----------------------------------------------------------------------------------------------------------------
Sperm whale (Physeter           Pelagic, deep sea  763 (560)--       EN.....  D...............  Unable to
 macrocephalus).                                    Northern GOM                                 determine.
                                                    stock.
Pygmy sperm whale (Kogia        Deep waters off    186 (90)--        NL.....  NC..............  Unable to
 breviceps) and Dwarf sperm      the shelf.         Northern GOM                                 determine.
 whale (Kogia sima).                                stock.
Cuvier's beaked whale (Ziphius  Pelagic..........  74 (36)--         NL.....  NC..............  Unable to
 cavirostris).                                      Northern GOM                                 determine.
                                                    stock.
Mesoplodon beaked whale         Pelagic..........  149 (77)--        NL.....  NC..............  Unable to
 (includes Blainville's beaked                      Northern GOM                                 determine.
 whale [M. densirostris],                           stock.
 Gervais' beaked whale [M.
 europaeus], and Sowerby's
 beaked whale [M. bidens].
Killer whale (Orcinus orca)...  Pelagic, shelf,    28 (14)--         NL.....  NC..............  Unable to
                                 coastal.           Northern GOM                                 determine.
                                                    stock.
Short-finned pilot whale......  Pelagic, shelf     2,415 (1,456)--   NL.....  NC..............  Unable to
(Globicephala macrorhynchus)..   coastal.           Northern GOM                                 determine.
                                                    stock.
False killer whale (Pseudorca   Pelagic..........  NA--Northern GOM  NL.....  NC..............  Unable to
 crassidens).                                       stock.                                       determine.
Melon-headed whale              Pelagic..........  2,235 (1,274)--   NL.....  NC..............  Unable to
 (Peponocephala electra).                           Northern GOM                                 determine.
                                                    stock.
Pygmy killer whale (Feresa      Pelagic..........  152 (75)--        NL.....  NC..............  Unable to
 attenuata).                                        Northern GOM                                 determine.
                                                    stock.

[[Page 33384]]

 
Risso's dolphin (Grampus        Deep water,        2,442 (1,563)--   NL.....  NC..............  Unable to
 griseus).                       seamounts.         Northern GOM                                 determine.
                                                    stock.
Bottlenose dolphin (Tursiops    Offshore,          NA (NA)--32       NL.....  NC..............  Unable to
 truncatus).                     inshore,           Northern GOM              S--32 stocks       determine.
                                 coastal,           Bay, Sound and             inhabiting the
                                 estuaries.         Estuary stocks.            bays, sounds,
                                                   NA (NA)--                   and estuaries
                                                    Northern GOM               along GOM
                                                    continental                coast, and GOM
                                                    shelf stock.               western coastal
                                                   7,702 (6,551)--             stock.
                                                    GOM eastern
                                                    coastal stock.
                                                   2,473 (2,004)--
                                                    GOM northern
                                                    coastal stock.
                                                   NA (NA)--GOM
                                                    western coastal
                                                    stock.
                                                   5,806 (4,230)--
                                                    Northern GOM
                                                    oceanic stock.
Rough-toothed dolphin (Steno    Pelagic..........  624 (311)--       NL.....  NC..............  Unable to
 bredanensis).                                      Northern GOM                                 determine.
                                                    stock.
Fraser's dolphin                Pelagic..........  NA (NA)--         NL.....  NC..............  Unable to
 (Lagenodelphis hosei).                             Northern GOM                                 determine.
                                                    stock.
Striped dolphin (Stenella       Pelagic..........  1,849 (1,041)--   NL.....  NC..............  Unable to
 coeruleoalba).                                     Northern GOM                                 determine.
                                                    stock.
Pantropical spotted dolphin     Pelagic..........  50,880 (40,699)-- NL.....  NC..............  Unable to
 (Stenella attenuata).                              Northern GOM                                 determine.
                                                    stock.
Atlantic spotted dolphin        Coastal and        NA (NA)--         NL.....  NC..............  Unable to
 (Stenella frontalis).           pelagic.           Northern GOM                                 determine.
                                                    stock.
Spinner dolphin (Stenella       Mostly pelagic...  11,441 (6,221)--  NL.....  NC..............  Unable to
 longirostris).                                     Northern GOM                                 determine.
                                                    stock.
Clymene dolphin (Stenella       Pelagic..........  129 (64)--        NL.....  NC..............  Unable to
 clymene).                                          Northern GOM                                 determine.
                                                    stock.
----------------------------------------------------------------------------------------------------------------
                                                    Sirenians
----------------------------------------------------------------------------------------------------------------
West Indian (Florida) manatee   Coastal, rivers,   3,802--U.S.       EN.....  D...............  Increasing or
 (Trichechus manatus             and estuaries.     stock.                                       stable
 latrostris).                                                                                    throughout much
                                                                                                 of Florida.
----------------------------------------------------------------------------------------------------------------
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\ NMFS Draft 2012 Stock Assessment Reports.
\4\ USFWS Stock Assessment Reports.

    Refer to sections 3 and 4 of USGS'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 USGS 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

[[Page 33385]]

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, but NMFS expects the disturbance to be 
localized and short-term. 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 11821, February 20, 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 USGS'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 11821, February 20, 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 the notice of the 
proposed IHA (78 FR 11821, February 20, 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.
    Recent work by Andre et al. (2011) purports to present the first 
morphological and ultrastructural evidence of massive acoustic trauma 
(i.e., permanent and substantial alterations of statocyst sensory hair 
cells) in four cephalopod species subjected to low-frequency sound. The 
cephalopods, primarily cuttlefish, were exposed to continuous 40 to 400 
Hz sinusoidal wave sweeps (100% duty cycle and 1 second sweep period) 
for two hours while captive in relatively small tanks (one 2,000 liter 
[L, 2 m\3\] and one 200 L [0.2 m\3\] tank). The received SPL was 
reported as 1575 dB re 1 [mu]Pa, with peak levels at 175 dB 
re 1 [mu]Pa. As in the McCauley et al. (2003) paper on sensory hair 
cell damage in pink snapper as a result of exposure to seismic sound, 
the cephalopods were subjected to higher sound levels than they would 
be under natural conditions, and they were unable to swim away from the 
sound source.

Mitigation

    In order to issue an ITA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable 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.
    USGS 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 ``Final Programmatic Environmental Impact Statement/Overseas 
Environmental Impact Statement for Marine Seismic Research Funded by 
the National Science Foundation or Conducted by the U.S. Geological 
Survey;''
    (2) Previous IHA applications and IHAs approved and authorized by 
NMFS; and
    (3) Recommended best practices in Richardson et al. (1995), Pierson 
et al. (1998), and Weir and Dolman, (2007).
    To reduce the potential for disturbance from acoustic stimuli 
associated with the activities, USGS and/or its designees shall 
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.
    Exclusion Zones--USGS use radii to designate exclusion and buffer 
zones and to estimate take for marine mammals. Table 1 (presented 
earlier in this document) shows the distances at which one would expect 
to receive three sound levels (160, 180, and 190 dB) from the 18 airgun 
array and a single airgun. The 180 dB and 190 dB level shut-down 
criteria are applicable to cetaceans and pinnipeds, respectively, as 
specified by NMFS (2000). USGS 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 105 in\3\ GI airguns, in relation 
to distance and direction from the airguns (see Figure 2 of the IHA 
application). USGS has used the modeling by L-DEO to determine the 
buffer and exclusion zones for this seismic survey. The model does not 
allow for bottom interactions, and is most directly applicable to deep 
water. Based on the modeling, estimates of the maximum distances from 
the GI airguns where sound levels are predicted to be 190, 180, and 160 
dB re 1 [mu]Pa (rms) in deep water were determined (see Table 1 above).
    Empirical data concerning the 190, 180, and 160 dB (rms) distances 
were acquired for various airgun arrays based on measurements during 
the acoustic verification studies conducted by L-DEO in the northern 
GOM in 2003 (Tolstoy et al., 2004) and 2007 to 2008 (Tolstoy et al., 
2009). Results of the 36 airgun array are not relevant for the 2 GI 
airguns to be used in the survey. The empirical data for the 6, 10, 12, 
and 20 airgun arrays indicate that, for deep water, the L-DEO model 
tends to overestimate the received sound levels at a given distance 
(Tolstoy et al., 2004). Measurements were not made for the two GI 
airgun array in deep water; however, USGS propose to use the safety 
radii predicted by L-DEO's model for the GI airgun operations in deep 
water, although they are likely conservative given the empirical 
results for the other arrays. The 180 and 190 dB (rms) radii are shut-
down criteria applicable to cetaceans and pinnipeds, respectively, as 
specified by NMFS (2000); these levels were used to establish exclusion 
zones. Therefore, the assumed 180 and 190 dB radii are 70 m (229.7 ft) 
and 20 m (65.6 ft), 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 2 summarizes the predicted distances at which sound levels 
(160, 180, and 190 dB [rms]) are expected to be received from the two 
airgun array operating in deep water (greater than 1,000 m [3,280 ft]) 
depths. For the project, USGS plans to use the distances for the two 
105 in\3\ GI airguns for the single 35 in\3\ GI airgun, for the 
determination of the buffer and exclusion zones since this represents

[[Page 33386]]

the largest and therefore most conservative distances determined by the 
model results provided by L-DEO.

  Table 2--Modeled (Two 105 in\3\ GI Airgun Array) Distances to Which Sound Levels >= 190, 180, and 160 dB re: 1 [mu]Pa (rms) Could Be Received in Deep
                                    Water During the Survey in the Deep Water of the Northwest GOM, April to May 2013
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Predicted RMS radii distances (m) for 2 airgun array
       Source and volume         Tow depth (m)   Water depth (m)  --------------------------------------------------------------------------------------
                                                                              190 dB                       180 dB                       160 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Two GI Airguns (105 in\3\)....               3  Deep (>1,000)....  20 m (65.6 ft).............  70 m (229.7 ft)............  670 m (2,198.2 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--USGS 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, USGS will not resume airgun activity until 
the marine mammal has cleared the exclusion zone. USGS 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, killer, and 
beaked whales).
    Although power-down procedures are often standard operating 
practice for seismic surveys, they are not planned 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. USGS 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. USGS proposes that, for the present cruise, this period would 
be approximately 15 minutes. L-DEO and Scripps Institution of 
Oceanography (SIO) has used similar periods (approximately 15 minutes) 
during previous low-energy seismic surveys.
    Ramp-up will begin with a single GI airgun (105 in\3\). The second 
GI airgun (105 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, USGS 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, by only where the 
exclusion zone is small enough to be visible. USGS 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

[[Page 33387]]

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

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

    USGS'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 deep water of the northwestern 
GOM, at least three PSOs will be based aboard the Pelican. USGS 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 Pelican 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. Two locations are likely 
as observation stations onboard the Pelican. When stationed on the aft 
control station on the upper deck (01 level), the eye level will be 
approximately 12 m (39.3 ft) above sea level, and the PSO will have an 
approximately 210[deg] view aft of the vessel centered on the seismic 
source location. At the bridge station, the eye level will be 
approximately 13 m (42.7 ft) above sea level, and the location will 
offer a full 360[deg] view around the entire vessel. During daytime, 
the PSO(s) will scan the area around the vessel systematically with 
reticle binoculars (e.g., 7 x 50 Fujinon), optical range-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 Pelican 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. The data accuracy 
will be verified by the PSOs at sea, and preliminary reports will be 
prepared during the field program and summaries forwarded to the 
operating institution's shore facility weekly or more frequently.
    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

[[Page 33388]]

seen at times with and without seismic activity.
    USGS 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: https://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), USGS 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 
Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov, and the NMFS 
Southeast Region Marine Mammal Stranding Network at 877-433-8299 
(Blair.Mase@noaa.gov and Erin.Fougeres@noaa.gov) or the Florida Marine 
Mammal Stranding Hotline at 888-404-3922. The report must include the 
following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with USGS to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. USGS may not resume their 
activities until notified by NMFS via letter or email, or telephone.
    In the event that USGS 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), 
USGS 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 Jolie.Harrison@noaa.gov and 
Howard.Goldstein@noaa.gov, and the NMFS Southeast Region Marine Mammal 
Stranding Network (877-433-8299) and/or by email to the Southeast 
Regional Stranding Coordinator (Blair.Mase@noaa.gov) and Southeast 
Regional Stranding Program Administrator (Erin.Fougeres@noaa.gov). The 
report must include the same information identified in the paragraph 
above. Activities may continue while NMFS reviews the circumstances of 
the incident. NMFS will work with USGS to determine whether 
modifications in the activities are appropriate.
    In the event that USGS 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), USGS 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 
Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov, and the NMFS 
Southeast Regional Marine Mammal Stranding Network (877-433-8299), and/
or by email to the Southeast Regional Stranding Coordinator 
(Blair.Mase@noaa.gov) and Southeast Regional Stranding Program 
Administrator (Erin.Fougeres@noaa.gov), within 24 hours of discovery. 
USGS 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 deep water of the northwestern 
GOM. Acoustic stimuli (i.e., increased underwater sound) generated 
during the operation of the seismic airgun array are expected to result 
in the behavioral disturbance of some marine mammals. There is no 
evidence that the planned activities for which USGS seeks the IHA could 
result in injury, serious injury, or mortality. The required mitigation 
and monitoring measures will minimize any potential risk for injury, 
serious injury, or mortality.
    The following sections describe USGS's methods to estimate take by 
incidental harassment and present the applicant's estimates of the 
numbers of

[[Page 33389]]

marine mammals that could be affected during the seismic program in the 
deep water of the northwestern GOM. The estimates are based on a 
consideration of the number of marine mammals that could be harassed by 
approximately 1,480 km (799.1 nmi) of seismic operations with the two 
GI airgun array to be used. The size of the 2D seismic survey area in 
2013 is approximately 356 km\2\ (103.8 nmi\2\) (approximately 445 km\2\ 
[129.7 nmi\2\]), as depicted in Figure 1 of the IHA application.
    USGS assumes that, during simultaneous operations of the airgun 
array and the other sources, any marine mammals close enough to be 
affected by the sub-bottom profiler would already be affected by the 
airguns. However, whether or not the airguns are operating 
simultaneously with the other sources, marine mammals are expected to 
exhibit no more than short-term and inconsequential responses to the 
sub-bottom profiler given their characteristics (e.g., narrow, 
downward-directed beam) and other considerations described previously. 
Such reactions are not considered to constitute ``taking'' (NMFS, 
2001). Therefore, USGS provides no additional allowance for animals 
that could be affected by sound sources other than airguns.
    USGS used spring densities reported in Table A-9 of Appendix A of 
the Bureau of Ocean Energy Management, Regulation and Enforcement's 
(BOEMRE, now the BOEM and BSEE) ``Request for incidental take 
regulations governing seismic surveys on the Outer Continental Shelf 
(OCS) of the Gulf of Mexico'' (BOEMRE, 2011). Those densities were 
calculated from the U.S. Navy's ``OPAREA Density Estimates'' (NODE) 
database (DoN, 2007b). The density estimates are based on the NMFS-
Southeast Fisheries Science Center (SEFSC) shipboard surveys conducted 
from 1994 to 2006 and were derived using a model-based approach and 
statistical analysis of the existing survey data. The outputs from the 
NODE database are four seasonal surface density plots of the GOM for 
each of the marine mammal species occurring there. Each of the density 
plots was overlaid with the boundaries of the 9 acoustic model regions 
used in Appendix A of BOEMRE (2011). USGS used the densities for 
Acoustic Model Region 8, which corresponds roughly with the deep waters 
(greater than 1,000 m) of the BOEMRE GOM Central Planning Area, and 
includes the GC955 and WR313 study sites.

 Table 3--Estimated Densities and Possible Number of Marine Mammal Species That Might Be Exposed to Greater Than
     or Equal to 160 dB During USGS's Seismic Survey (Ensonified Area 445.4 km\2\) in the Deep Water of the
                                       Northwestern GOM, April to May 2013
----------------------------------------------------------------------------------------------------------------
                                                       Calculated take
                                                       (i.e., estimated
                                                          number of           Approximate
                                       Density\a\        individuals      percentage of best     Requested take
             Species                (/1,000   exposed to sound   population estimate  authorization \3\
                                         km\2\)        levels >= 160 dB  of stock (calculated
                                                       re 1 [micro]Pa)         take) \2\
                                                             \1\
----------------------------------------------------------------------------------------------------------------
                                                   Mysticetes
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale.......                 NA                 NA  NA..................                 NA
Humpback whale...................                 NA                 NA  NA..................                 NA
Minke whale......................                 NA                 NA  NA..................                 NA
Bryde's whale....................                0.1                  0  0...................                  0
Sei whale........................                 NA                 NA  NA..................                 NA
Fin whale........................                 NA                 NA  NA..................                 NA
Blue whale.......................                 NA                 NA  NA..................                 NA
----------------------------------------------------------------------------------------------------------------
                                                   Odontocetes
----------------------------------------------------------------------------------------------------------------
Sperm whale......................                4.9                  2  1.7 (0.26)..........                 13
Kogia spp. (Pygmy and dwarf sperm                2.1                  1  1.1 (0.54)..........                  2
 whale).
Small (Mesoplodon and Cuvier's)                  3.7                  2  1.3 (1.3)--                           2
 beaked whale.                                                            Mesoplodon beaked
                                                                          whale.
                                                                         2.7 (2.7)--Cuvier's
                                                                          beaked whale.
Killer whale.....................               0.40                  0  0...................                  0
Short-finned pilot whale.........                6.3                  3  0.79 (0.12).........                 19
False killer whale...............                2.7                  1  NA..................                 36
Melon-headed whale...............                9.1                  4  5.3 (0.18)..........                118
Pygmy killer whale...............                1.1                  0  0...................                  0
Risso's dolphin..................               10.0                  4  0.37 (0.16).........                  9
Bottlenose dolphin...............                4.8                  2  NA (NA)--32 Northern                 18
                                                                          GOM Bay, Sound and
                                                                          Estuary stocks.
                                   .................  .................  NA (NA)--Northern     .................
                                                                          GOM continental
                                                                          shelf stock.
                                   .................  .................  0.23 (0.03)--GOM      .................
                                                                          eastern coastal
                                                                          stock.
                                   .................  .................  0.73 (0.08)--GOM      .................
                                                                          northern coastal
                                                                          stock.
                                   .................  .................  NA (NA)--GOM western  .................
                                                                          coastal stock.
                                   .................  .................  0.28 (0.03)--         .................
                                                                          Northern GOM
                                                                          oceanic stock.
Rough-toothed dolphin............                6.7                  3  2.6 (0.48)..........                 16
Fraser's dolphin.................                1.9                  1  NA (NA).............                117
Striped dolphin..................               51.5                 23  2.43 (1.24).........                 45
Pantropical spotted dolphin......              582.6                259  0.51 (0.51).........                259
Atlantic spotted dolphin.........                2.2                  1  NA (NA).............                 15
Spinner dolphin..................               72.6                 32  0.86 (0.28).........                 99

[[Page 33390]]

 
Clymene dolphin..................               45.6                 20  15.5 (15.5).........                 20
----------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ Calculated take is density times the area ensonified to >160 dB (rms) around the planned seismic lines,
  increased by 25%.
\2\ Stock sizes are best populations from NMFS Draft 2012 Stock Assessment Reports (see Table 2 above).
\3\ Requested Take Authorization increased to mean group size.

    USGS 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 [micro]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. 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 in the square grid are closely spaced 
(approximately 100 m [328.1 ft] apart at the GC955 site and 250 m 
[820.2 ft] apart at the WR313 site) relative to the 160 dB distance 
(670 m [2,198.2 ft]). Thus, the area including overlap is 6.5 times the 
area excluding overlap at GC955 and 5.3 times the area excluding 
overlap at WR313, so a marine mammal that stayed in the survey areas 
during the entire survey could be exposed approximately 6 or 7 times on 
average. While some individuals may be exposed multiple times since the 
survey tracklines are spaced close together; 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 [micro]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 356 km\2\ 
(approximately 445 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 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 Pelican 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).
    USGS's estimates of exposures to various sound levels assume that 
the surveys will be carried out in full (i.e., approximately 8 days of 
seismic airgun operations for the two study sites, respectively); 
however, the ensonified areas calculated using the planned number of 
line-kilometers have been increased by 25% to accommodate lines that 
may need to be repeated, equipment testing, account for repeat 
exposure, 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 3 (Table 3 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 3 (Table 3 
of the IHA application). The requested take authorization has been 
increased to the average mean group sizes in the GOM in 1996 to 2001 
(Mullin and Fulling, 2004) and 2003 and 2004 (Mullin, 2007) in cases 
where the calculated number of individuals exposed was between one and 
the mean group size.
    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) as 
follows: 0 baleen whales, 13 sperm whales, 1 dwarf/pygmy sperm whale, 
and 2 beaked whales, (including Cuvier's and Mesoplodon beaked whales) 
could be taken by Level B harassment during the seismic survey. Most of 
the cetaceans potentially taken by Level B harassment are delphinids; 
pantropical spotted, spinner, Clymene, and striped dolphins are 
estimated to be the most common species in the area, with estimates of 
259, 32, 20, and 23, which would

[[Page 33391]]

represent 0.51, 0.28, 15.5, and 1.24% of the affected populations or 
stocks, respectively.

Encouraging and Coordinating Research

    USGS will coordinate the planned marine mammal monitoring program 
associated with the seismic survey with any parties that express 
interest in this activity.

Negligible Impact and Small Numbers Analysis Determination

    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival.'' In making a negligible impact determination, NMFS 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 (i.e., 
the manner and degree in which the measure is likely to reduce adverse 
impacts to marine mammals, the likely effectiveness of the measures, 
and the practicability of implementation).
    For reasons stated previously in this document, in the notice of 
the proposed IHA (78 FR 11821, February 20, 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 USGS's planned marine seismic surveys, and 
none are authorized by NMFS. Table 3 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 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 the NMFS 
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 day.
    Of the 28 marine mammal species under NMFS jurisdiction that may or 
are known to likely to occur in the study area, six are listed as 
threatened or endangered under the ESA: North Atlantic right, 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 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), USGS 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 19 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 3 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 deep water of the northwestern 
GOM, April to May 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 marine seismic survey in the deep water of the Gulf of Mexico, April 
to May 2013, may result, at worst, in a temporary modification in 
behavior and/or low-

[[Page 33392]]

level physiological effects (Level B harassment) of small numbers of 
certain species of marine mammals. See Table 3 for the requested 
authorized take numbers of marine mammals.

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

    Section 101(a)(5)(D) of the MMPA also requires NMFS to determine 
that the authorization will not have an unmitigable adverse effect on 
the availability of marine mammal species or stocks for subsistence 
use. There are no relevant subsistence uses of marine mammals in the 
study area (in the deep water of the northwest GOM) that implicate MMPA 
section 101(a)(5)(D).

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 North 
Atlantic right, humpback, sei, fin, blue, and sperm whales. USGS did 
not request take of endangered North Atlantic right, humpback, sei, 
fin, and blue whales due to the low likelihood of encountering this 
species during the cruise. Under section 7 of the ESA, USGS has 
initiated formal consultation with the NMFS, Office of Protected 
Resources, Endangered Species Act Interagency Cooperation Division, on 
this seismic survey. NMFS's Office of Protected Resources, Permits and 
Conservation Division, has also initiated and engaged in formal 
consultation under section 7 of the ESA with NMFS's Office of Protected 
Resources, Endangered Species Act Interagency Cooperation Division, on 
the issuance of an IHA under section 101(a)(5)(D) of the MMPA 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 April 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 of the ITS is 
likewise a mandatory requirement of the IHA. 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

    To meet NMFS's NEPA requirements for the issuance of an IHA to 
USGS, USGS provided NMFS an ``Environmental Assessment and 
Determination Pursuant to the National Environmental Policy Act, 42 
U.S.C. 4321 et seq. and Executive Order 12114 Low-Energy Marine Seismic 
Survey by the U.S. Geological Survey in the Deepwater Gulf of Mexico, 
April-May 2013,'' which incorporates a draft ``Environmental Assessment 
of Low-Energy Marine Geophysical Survey by the U.S. Geological Survey 
in the Northwestern Gulf of Mexico, April-May 2013,'' prepared by LGL 
Ltd., Environmental Research Associates on behalf of USGS. The EA 
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 has fully evaluated the 
potential direct, indirect, and cumulative effects on the human 
environment prior to making a final decision on the IHA application and 
deciding whether or not to issue a Finding of No Significant Impact 
(FONSI). 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 FONSI. An Environmental Impact Statement 
is not required and will not be prepared for the action.

Authorization

    NMFS has issued an IHA to USGS for the take, by Level B harassment, 
of small numbers of marine mammals incidental to conducting a low-
energy marine seismic survey in the deep water of the northwestern GOM, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.

    Dated: May 30, 2013.
Helen Golde,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2013-13185 Filed 6-3-13; 8:45 am]
BILLING CODE 3510-22-P