Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a Marine Geophysical Survey in the Atlantic Ocean Off the Eastern Seaboard, August to September 2014 and April to August 2015, 52121-52163 [2014-20475]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 79, Number 169 (Tuesday, September 2, 2014)]
[Notices]
[Pages 52121-52163]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-20475]



[[Page 52121]]

Vol. 79

Tuesday,

No. 169

September 2, 2014

Part II





 Department of Commerce





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 National Oceanic and Atmospheric Administration





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Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to a Marine Geophysical Survey in the 
Atlantic Ocean Off the Eastern Seaboard, August to September 2014 and 
April to August 2015; Notices

Federal Register / Vol. 79 , No. 169 / Tuesday, September 2, 2014 / 
Notices

[[Page 52122]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD214


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Marine Geophysical Survey in the 
Atlantic Ocean Off the Eastern Seaboard, August to September 2014 and 
April to August 2015

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

ACTION: Notice; issuance of an Incidental Harassment Authorization 
(IHA).

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SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA), 
notification is hereby given that NMFS has issued an IHA to the United 
States (U.S.) Geological Survey (USGS), Lamont-Doherty Earth 
Observatory of Columbia University (L-DEO), and National Science 
Foundation (NSF) to take marine mammals, by Level B harassment, 
incidental to conducting a marine geophysical (seismic) survey in the 
Atlantic Ocean off the Eastern Seaboard, August to September 2014 and 
April to August 2015.

DATES: Effective August 21, 2014 to August 20, 2015.

ADDRESSES: A copy of the IHA and the application are available by 
writing to Jolie Harrison, Supervisor, Incidental Take Program, 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 below (see FOR FURTHER 
INFORMATION CONTACT).
    An electronic copy of the IHA application containing a list of the 
references used in this document may be obtained by writing to the 
address specified above, telephoning the contact listed below (see FOR 
FURTHER INFORMATION CONTACT) or visiting the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Documents 
cited in this notice, including the IHA application, may also be 
viewed, by appointment, during regular business hours at the 
aforementioned address.
    An ``Environmental Assessment for Seismic Reflection Scientific 
Research Surveys during 2014 and 2015 in Support of Mapping the U.S. 
Atlantic Seaboard Extended Continental Margin and Investigating Tsunami 
Hazards'' (EA), was prepared by RPS Evan-Hamilton, Inc., an RPS Group 
Company, in association with YOLO Environmental, Inc., GeoSpatial 
Strategy Group, and Ecology and Environment, Inc., on behalf of USGS. 
The USGS's EA and Finding of No Significant Impact are available online 
at: https://woodshole.er.usgs.gov/project-pages/
environmentalcompliance/reports/
FONSI%20SIGNED%20&%20Attachment1.pdf. NMFS also issued a Biological 
Opinion under Section 7 of the Endangered Species Act (ESA) to evaluate 
the effects of the seismic survey and IHA on marine species listed as 
threatened and endangered. The NMFS Biological Opinion is available 
online at: https://www.nmfs.noaa.gov/pr/consultations/opinions.htm.

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

SUPPLEMENTARY INFORMATION:

Background

    Section 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.), 
directs the Secretary of Commerce (Secretary) to allow, upon request, 
the incidental, but not intentional, taking of small numbers of marine 
mammals, by United States citizens who engage in a specified activity 
(other than commercial fishing) within a specified geographical region 
if certain findings are made and either regulations are issued or, if 
the taking is limited to harassment, a notice of a proposed 
authorization is provided to the public for review.
    An authorization for the incidental takings 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), and if the permissible methods of taking requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``. . . an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    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 (behavioral) harassment occurs 
at the level of the individual(s) and does not assume any resulting 
population-level consequences.

Summary of Request

    On March 27, 2014, NMFS received an application from the USGS, L-
DEO, and NSF (hereafter referred to as 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 marine seismic survey within 
the Exclusive Economic Zone (EEZ) and on the high seas (i.e., 
International Waters) to map the U.S. Atlantic Eastern Seaboard 
Extended Continental Shelf (ECS) region and investigate tsunami hazards 
during August to September 2014 and April to August 2015. USGS plan to 
use one source vessel, the R/V Marcus G. Langseth (Langseth) and a 
seismic airgun array and a hydrophone streamer to collect seismic data 
as part of the seismic survey in the Atlantic Ocean off the Eastern 
Seaboard. In addition to the planned operation of the seismic airgun 
array and hydrophone streamer, USGS intends to operate a multi-beam 
echosounder and a sub-bottom profiler continuously during the seismic 
operations in order to map the ocean floor. The multi-beam echosounder 
and sub-bottom profiler would not be operated during transits at the 
beginning and end of the seismic survey. NMFS determined that the IHA 
application was adequate and complete on May 14, 2014. NMFS published a 
notice making preliminary determinations and proposing to issue an IHA 
on June 23, 2014 (79 FR 35642). 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 are likely to result 
in the take of marine mammals. Take, by Level B harassment only, of 
individuals of 34 species of marine mammals is anticipated to result 
from the specified activity. Take is not expected to result from the 
use of the multi-beam echosounder or 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]; 8.5 kilometers per hour [km/
hr]; 5.3 miles per hour [mph]) during seismic acquisition within the 
survey, for a relatively short period of time

[[Page 52123]]

(approximately two 17 to 18 day legs), and it is likely that any marine 
mammal will be able to avoid the vessel.

Description of the Specified Activity

Overview

    USGS plans to conduct a marine seismic survey within the EEZ and on 
the high seas to map the U.S. Atlantic Eastern Seaboard ECS region and 
investigate tsunami hazards during August to September 2014 and April 
to August 2015. USGS plans to use one source vessel, the Langseth, and 
a 36-airgun array and one 8 kilometer (km) (4.3 nautical mile [nmi]) 
hydrophone streamer to conduct the conventional seismic survey. In 
addition to the operations of airguns, the USGS intends to operate a 
multi-beam echosounder and a sub-bottom profiler on the Langseth during 
the seismic survey to map the ocean floor.

Dates and Duration

    The Langseth will depart from Newark, New Jersey on August 21, 
2014. The seismic survey is expected to take approximately 21 days to 
complete. At-sea time is planned to be approximately 21 days, with 18 
days planned for airgun operations and 3 days planned for transiting, 
deployment and recovery of equipment. Approximately a one day transit 
will be required at the beginning and end of the program. When the 2014 
survey is completed, the Langseth will then transit to Norfolk, 
Virginia. The survey schedule is inclusive of weather and other 
contingency (e.g., equipment failure) time. The planned activities for 
2015 will be virtually identical to the planned activities for 2014 as 
geographic area, duration, and trackline coverage are similar. The 
exact dates for the planned activities in 2015 are uncertain, but are 
scheduled to occur within the April to August timeframe. The exact 
dates of the planned activities depend on logistics and weather 
conditions.

Specified Geographic Region

    The planned survey will be bounded by the following geographic 
coordinates:
40.5694[deg] North, -66.5324[deg] West;
38.5808[deg] North, -61.7105[deg] West;
29.2456[deg] North, -72.6766[deg] West;
33.1752[deg] North, -75.8697[deg] West;
39.1583[deg] North, -72.8697[deg] West;
    The planned activities for 2014 will generally occur towards the 
periphery of the planned study area (see Figures 1 and 2 of the IHA 
application). The planned activities for 2015 would survey more of the 
central portions of the study area. The tracklines planned for both 
2014 and 2015 would be in International Waters (approximately 80% in 
2014 and 90% in 2015) and in the U.S. EEZ. Water depths range from 
approximately 1,450 to 5,400 meters (m) (4,593.2 to 17,716.5 feet [ft]) 
(see Figure 1 and 2 of the IHA application); no survey lines will 
extend to water depths less than 1,000 m.

Detailed Description of the Specified Activity

    USGS, Coastal and Marine Geology Program, (Primary Investigator 
[PI], Dr. Deborah Hutchinson) plans to conduct a regional high-energy, 
two-dimensional (2D) seismic survey in the northwest Atlantic Ocean 
within the U.S. EEZ and extending into International Waters (i.e., high 
seas) as far as 648.2 km (350 nmi) from the U.S. coast (see Figure 1 of 
the IHA application). Water depths in the survey area range from 
approximately 1,400 to greater than 5,400 meters (m) (4,593.2 to 
17,716.5 feet [ft]). The seismic survey will be scheduled to occur in 
two phases; the first phase during August to September 2014 (for 
approximately 17 to 18 days of airgun operations), and the second phase 
between April and August 2015 (for approximately 17 to 18 days of 
airgun operations, specific dates to be determined). The planned 
activities for both Phase 1 and Phase 2 are included in this IHA 
application (see Figure 2 of the IHA application). Some minor deviation 
from these dates is possible, depending on logistics and weather.
    USGS plans to use conventional seismic methodology to: (1) Identify 
the outer limits of the U.S. continental shelf, also referred to as the 
ECS as defined by Article 76 of the Convention of the Law of the Sea; 
and (2) study the sudden mass transport of sediments down the 
continental shelf as submarine landslides that may pose significant 
tsunamigenic (i.e., tsunami-related) hazards to the Atlantic and 
Caribbean coastal communities.
    The seismic survey will involve one source vessel, the Langseth. 
The Langseth will deploy an array of 36 airguns as an energy source 
with a total volume of approximately 6,600 in\3\. The receiving system 
will consist of one 8,000 m (26,246.7 ft) hydrophone streamer. As the 
airgun array is towed along the survey lines, the hydrophone streamer 
will receive the returning acoustic signals from the towed airgun array 
and transfer the data to the on-board processing system. The data will 
be processed on-board the Langseth as the seismic survey occurs.
    Each planned leg of the survey (2014 and 2015) will be 17 to 18 
days in duration (exclusive of transit and equipment deployment and 
recovery) and will comprise of approximately 3,165 km (1,709 nmi) of 
tracklines of 2D seismic reflection coverage. The airgun array will 
operate continuously during the seismic survey (except for equipment 
testing, repairs, implemented mitigation measures, etc.). Data will 
continue to be acquired between line changes, as the successive track 
segments can be surveyed as almost one continuous line. Line turns of 
90 and no greater than 120 degrees will be required to move from one 
line segment to the next. The 2014 seismic survey design consists 
primarily of the tracklines that run along the periphery of the overall 
study area, including several internal tracklines (see Figure 2 of the 
IHA application). The 2015 seismic survey design consists of additional 
dip and tie lines (i.e., dip lines are lines that are perpendicular to 
the north-south trend of the continental margin; strike lines are 
parallel to the margin; and tie lines are any line that connects other 
lines). The 2015 seismic survey design may be modified based on the 
2014 results.
    In addition to the operations of the airgun array, a Kongsberg EM 
122 multi-beam echosounder and a Knudsen Model 3260 Chirp sub-bottom 
profiler will also be operated from the Langseth continuously during 
airgun operations throughout the survey to map the ocean floor. The 
multi-beam and sub-bottom profiler will not operate during transits at 
the beginning and end of the survey. All planned geophysical data 
acquisition activities will be conducted by USGS with on-board 
assistance by the scientists who have planned the study. The vessel 
will be self-contained, and the crew will live aboard the vessel for 
the entire cruise.
    NMFS provided a detailed description of the planned activities in a 
previous notice for the proposed IHA (79 FR 35642, June 23, 2014). The 
activities to be conducted have not changed between the proposed IHA 
notice and this final notice announcing the issuance of the IHA. For a 
more detailed description of the authorized action, including vessel 
and acoustic source specifications, the reader should refer to the 
notice for the proposed IHA (79 FR 35642, June 23, 2014), the IHA 
application, EA, and associated documents referenced above this 
section.

Comments and Responses

    A notice of preliminary determinations and proposed IHA for the 
USGS's seismic survey was published in the Federal Register on June 23, 
2014 (79 FR 35642). During the 30-day public comment period, NMFS 
received comments from one private

[[Page 52124]]

citizen, Clean Ocean Action (COA); combined comments from Natural 
Resources Defense Council (NRDC), Humane Society of the United States 
(HSUS), Oceana, and Center for Biological Diversity (CBD) (hereafter 
referred to as NRDC et al.); and the Marine Mammal Commission 
(Commission). The comments are posted online at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Following are the 
substantive comments and NMFS's responses:

Effects Analyses

    Comment 1: The Commission is concerned that L-DEO's modeling to 
estimate mitigation zones and take estimates does not indicate or 
consider site-specific environmental conditions, including bathymetry 
and sound speed profiles. The reflective/refractive arrivals are the 
very measurements that should be accounted for in site-specific 
modeling and ultimately determine underwater sound propagation. The 
Commission states that ignoring those factors is a serious flaw of L-
DEO's model.
    The Commission recommends that NMFS (1) require USGS, L-DEO, and 
NSF to re-estimate the proposed exclusion and buffer zones and 
associated takes of marine mammals using site-specific operational 
parameters (e.g., tow depth, source level, number/spacing of active 
airguns) and site-specific environmental parameters (e.g., sound speed 
profiles, refraction in the water column, bathymetry/water depth, 
sediment properties/bottom loss, and wind speed) in the action area for 
the proposed IHA and (2) impose the same requirement for all future 
IHAs submitted by USGS, L-DEO, NSF, SIO, ASC, or any other related 
entity. The Commission encourages L-DEO to make comparisons at various 
sites, if it intends to continue using a model that does not 
incorporate site-specific parameters. The Commission disagrees with the 
conclusion that NMFS has indicated that NSF, L-DEO, and other relevant 
entities (USGS, SIO, etc.) are providing sufficient justification for 
their take estimates, given that the estimates are based on L-DEO's 
model or empirical measurements in the Gulf of Mexico and other recent 
activities have been dispersed throughout the world. The Commission 
states that in a recent sound exposure modeling workshop that was 
attended by numerous entities (including NMFS, NSF, L-DEO, USGS, and 
the Commission), experts confirmed that sound speed profiles and 
bathymetry/sediment characteristics were the most important factors 
affecting underwater sound propagation and should be included in 
related modeling. L-DEO's modeling presentation at indicated that the 
model was fast, inexpensive, and simple to use, and indicated that the 
model is more closely related to a source model that compares airgun 
arrays and that it is not representative of modeling in the actual 
environment. Therefore, the Commission remains concerned that the L-DEO 
model, which may not be applicable or accurate to the action area, is 
not based on the best available science and does not support its 
continued use.
    Response: At present, L-DEO cannot adjust their modeling 
methodology to add the environmental and site-specific parameters as 
requested by the Commission. NMFS is working with USGS, NSF, and L-DEO 
to explore ways to better consider site-specific information to inform 
the take estimates and development of mitigation measures in coastal 
areas for future seismic surveys with L-DEO and NSF, and NSF has been 
exploring different approaches in collaboration with L-DEO and other 
academic institutions with whom they collaborate. When available, NMFS 
will review and consider the final results from the L-DEO's expected 
publications (Crone et al., in prep.), in which the results of a 
calibration off the coast of Washington will be reported, and how they 
reflect on L-DEO's model.
    For this seismic survey, L-DEO developed the exclusion and buffer 
zones based on the conservative deep-water calibration results from 
Diebold et al. (2010). L-DEO's current modeling approach represents the 
best available information to reach NMFS's determinations for the IHA. 
The comparisons of L-DEO's model results and the field data collected 
in the Gulf of Mexico and Washington illustrate a degree of 
conservativeness built into L-DEO's model for deep water.
    NMFS acknowledges the Commission's concerns about L-DEO's current 
modeling approach for estimating exclusion and buffer zones and also 
acknowledge that L-DEO did not incorporate site-specific sound speed 
profiles, bathymetry, and sediment characteristics of the research area 
within the current approach to estimate those zones for this IHA. 
However, as described below, empirical data collected at two different 
sites and compared against model predictions indicate that other facets 
of the model (besides the site-specific factors cited above) do result 
in a conservative estimate of exposures in the cases tested.
    The USGS IHA application and EA describe the approach to 
establishing mitigation exclusion and buffer zones. In summary, L-DEO 
acquired field measurements for several array configurations at 
shallow- and deep-water depths during acoustic verification studies 
conducted in the northern Gulf of Mexico in 2003 (Tolstoy et al., 2004) 
and in 2007 and 2008 (Tolstoy et al., 2009). Based on the empirical 
data from those studies, L-DEO developed a sound propagation modeling 
approach that conservatively predicts received sound levels as a 
function of distance from a particular airgun array configuration in 
deep water. In 2010, L-DEO assessed their accuracy of their modeling 
approach by comparing the sound levels of the field measurements in the 
Gulf of Mexico study to their model predictions (Diebold et al., 2010). 
They reported that the observed sound levels from the field 
measurements fell almost entirely below the predicted mitigation radii 
curve for deep water (Diebold et al., 2010). Based on this information, 
L-DEO has shown that their model can reliably estimate the mitigation 
radii in deep water.
    L-DEO's model is most directly applicable to deep water. Reflected 
and refracted arrivals were considered in verifying L-DEO's model. 
Given the planned seismic survey is entirely in deep water, and the 
model has been demonstrated to be conservative in deep water, NMFS 
concludes that the L-DEO model is an effective means to aid in 
determining potential impacts to marine mammals from the planned 
seismic survey and estimating take numbers, as well as establishing 
buffer and exclusion zones for mitigation.
    During a March 2013 meeting, L-DEO discussed the L-DEO model with 
the Commission, NMFS, and NSF. L-DEO compared the Gulf of Mexico (GOM) 
calibration measurements (Tolstoy et al., 2004; Tolstoy et al., 2009; 
Diebold et al., 2010) comparison with L-DEO model results. L-DEO showed 
that at the calibration sites the model overestimated the size of the 
exclusion zones and, therefore, is likely precautionary in most cases. 
Based on the best available information that the current model 
overestimates mitigation zones, we will not require L-DEO to re-
estimate the proposed buffer and exclusion zones and associated number 
of marine mammal takes using operational and site-specific 
environmental parameters for this IHA.
    However, we continue to work with the USGS, NSF and L-DEO on 
verifying the accuracy of their model. L-DEO is

[[Page 52125]]

currently analyzing whether received levels can be measured in real-
time using the ship's hydrophone streamer to estimate the sound field 
around the ship and determine actual distances to the buffer and 
exclusion zones. Crone et al. (2013) are analyzing Langseth streamer 
data collected in 2012 off the Washington coast shelf and slope to 
measure received levels in situ up to 8 km (4.3 nmi) away from the 
ship. While results confirm the role that bathymetry plays in 
propagation, it also confirmed that empirical measurements from the GOM 
survey used to inform buffer and exclusion zones in shallow water and 
model results adapted for intermediate water depths also over-estimated 
the size of the zones for the Washington survey. Preliminary results 
were presented in a poster session at the American Geophysical Union 
fall meeting in December 2013 (Crone et al., 2013; available at: https://berna.ldeo.columbia.edu/agu2013/agu2013.pdf) and a peer-reviewed 
journal publication is anticipated in 2014. When available, NMFS will 
review and consider the final results and how they reflect on the L-DEO 
model.
    L-DEO has conveyed to NMFS that additional modeling efforts to 
refine the process and conduct comparative analysis may be possible 
with the availability of research fund and other resources. Obtaining 
research funds is typically through a competitive process, including 
those submitted to federal agencies. The use of models for calculating 
buffer and exclusion zone radii and developing take estimates are not a 
requirement of the MMPA ITA process. Furthermore, NMFS does not provide 
specific guidance on model parameters nor prescribes a specific model 
for applicants as part of the MMPA ITA process. There is a level of 
variability not only with parameters in models, but the uncertainty 
associated with data used in models and therefore the quality of the 
model results submitted by applicants. NMFS, however, takes all of this 
variability into consideration when evaluating applications. Applicants 
use models as a tool to evaluate potential impacts, estimate the number 
of takes of marine mammals, and for mitigation purposes. NMFS takes 
into consideration the model used and its results in determining the 
potential impacts to marine mammals; however, it is just a component of 
NMFS's analysis during the MMPA consultation process as NMFS also takes 
into consideration other factors associated with the proposed action, 
such as geographic location, duration of activities, context, 
intensity, etc. Takes generated by modeling are used as estimates, not 
absolutes, and are factored into NMFS's analysis accordingly. Of 
broader note, NMFS is currently pursuing methods that include site-
specific components to allow us to better cross-check isopleth and 
propagation predictions submitted by applicants. Using this 
information, NMFS could potentially recommend modifications to take 
estimates and/or mitigation zones, as appropriate.
    Comment 2: The Commission is unaware of changes to L-DEO's model 
that would explain why the estimated exclusion zones for the seismic 
survey (36-airgun array towed at 9 m depth) are smaller than previously 
authorized and the buffer zones are larger than previously authorized 
(75 FR 44770; 76 FR 49737; 76 FR 75525; 77 FR 25693; 77 FR 41755).
    Response: NMFS recognizes the Commission's statement that the 
estimated exclusion zones are smaller and buffer zones are larger than 
under previous IHAs. The table below compares the estimated 160, 180, 
and 190 dB buffer and exclusion zones for the current USGS IHA and 
previous IHAs for seismic surveys conducted by L-DEO or USGS on the 
Langseth.

   Table 1--Comparison of the Estimated 160, 180, and 190 dB Buffer and Exclusion Zones for the Current USGS IHA and Previous IHAs for Seismic Surveys
                                                       Conducted by L-DEO or USGS on the Langseth
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                                                                                                                    Predicted RMS distances (m)
           Seismic survey                Source and volume       Tow depth  (m)      Water depth  (m)    -----------------------------------------------
                                              (in\3\)                                                         160 dB          180 dB          190 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
USGS ECS Atlantic 2014..............  Single Bolt Airgun (40)  9................  Deep (>1,000).........             388             100             100
                                      36 Airgun Array (6,600)  9................  Deep (>1,000).........           5,780             927             286
L-DEO Northeastern Pacific 2012.....  Single Bolt Airgun (40)  6 to 15..........  Deep (>1,000).........             385              40              12
                                                                                  Intermediate (100 to               578              60              18
                                                                                   1,000).
                                                                                  Shallow (<100)........           1,050             296             150
                                      36 Airgun Array (6,600)  9................  Deep (>1,000).........           3,850             940             400
                                                                                  Intermediate (100 to            12,200           1,540             550
                                                                                   1,000).
                                                                                  Shallow (<100)........          20,550           2,140             680
                                      36 Airgun Array (6,600)  12...............  Deep (>1,000).........           4,400           1,100             460
                                                                                  Intermediate (100 to            13,935           1,810             615
                                                                                   1,000).
                                                                                  Shallow (<100)........          23,470           2,250             770
                                      36 Airgun Array (6,600)  15...............  Deep (>1,000).........           4,490           1,200             520
                                                                                  Intermediate (100 to            15,650           1,975             690
                                                                                   1,000).
                                                                                  Shallow (<100)........          26,350           2,750             865
L-DEO Northwest Pacific 2012........  Single Bolt Airgun (40)  9................  Deep (>1,000).........             385              40              12
                                      36 Airgun Array (6,600)  9................  Deep (>1,000).........           3,850             940             400
L-DEO Line Islands 2012.............  Two GI Airgun Array      3................  Deep (>1,000).........             670              70              20
                                       (105).
L-DEO Line Islands 2011.............  Single Bolt Airgun (40)  9................  Deep (>1,000).........             385              40              12
                                      36 Airgun Array (6,600)  9................  Deep (>1,000).........           3,850             940             400
USGS Bering 2011....................  Single Bolt Airgun (40)  9................  Deep (>1,000).........             385              40              12
                                      36 Airgun Array (6,600)  9................  Deep (>1,000).........           3,850             940             400
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 52126]]

    The previous IHA applications and EAs provided by L-DEO or USGS for 
this airgun array were based on the empirical results of Tolstoy et al. 
(2009) and adjusted for tow depth. During the Langseth calibration, a 
hydrophone was used at a depth of 350 to 500 m (1,148.3 to 1,640.4 ft) 
at a deep-water site. However, since the hydrophone wasn't necessarily 
sampling the maximum in the water column down to 2,000 m (6,561.7 ft), 
the distances to the 160, 180, and 190 dB threshold contours cannot be 
used directly as buffer and exclusion zones. The previous documents use 
160 dB (rms) from Tolstoy et al. (2009) and adjust for tow depth, and 
in recent documents use the 150 dB SEL contour from Diebold et al. 
(2010) model, which accounts for the large difference in the 160 dB 
buffer zone (3,850 vs 5,780 m). For the 190 dB exclusion zone, the rms 
vs SEL metrics are a significant factor. In Figures 7 and 8 of Tolstoy 
et al. (2009), there is not an exact 10 dB difference between SEL and 
90% rms in the empirical data at short distances (200 to 500 m). In 
recent documents, L-DEO or USGS has been using the L-DEO modeling; 
modeling results are given as SEL then converted to rms values using a 
fixed 10 dB difference. Using this approach, the distance to 190 dB rms 
(approximately 180 dB SEL) is less than what was obtained using rms 
values of the empirical measurements. However, the distance is not 
underestimated with respect to the trend of SEL values of the empirical 
measurements obtained at the closest ranges in Figure 8 of Tolstoy et 
al. (2009) and also demonstrated in Figure 10 of Diebold et al. (2010). 
The main reason for the significant fluctuations in modeling (dB 
discount with SEL value) is based on converting the values calculated 
as 90% rms and values obtained as SEL +10 dB. The table below compares 
L-DEO's previous (Tolstoy et al., 2009) and current (Tolstoy et al., 
2009; Diebold et al., 2010) approach to acoustic propagation.

Table 2--Comparison of L-DEO's Previous and Current Approach to Acoustic
                               Propagation
------------------------------------------------------------------------
                                                     Current approach to
                              Previous approach to  acoustic propagation
         Categories           acoustic propagation    (Tolstoy et al.,
                                (Tolstoy et al.,     2009 and Diebold et
                                      2009)              al., 2010)
------------------------------------------------------------------------
Model Approach..............  Ray trace of direct   Ray trace of direct
                               arrivals and source   arrivals and source
                               ghosts (reflection    ghosts (reflection
                               at the air-water      at the air-water
                               interface at the      interface at the
                               array) from the       array) from the
                               array to the          array to the
                               receivers.            receivers.
Model Assumptions...........  Constant velocity,    Constant velocity,
                               infinite homogenous   infinite homogenous
                               ocean layer,          ocean layer,
                               seafloor unbounded.   seafloor unbounded.
                               Cross-line model      Cross-line model
                               more conservative     more conservative
                               than in-line model.   than in-line model.
Propagation Measurements      36 airguns (6,600     36 airguns (6,600
 Analyzed.                     in\3\), 6 m tow       in\3\), 6 m tow
                               depth, 1,600 m        depth, 50 m
                               (deep).               (shallow).
                              36 airguns (6,600
                               in\3\), 6 m tow
                               depth, 600 to 1,100
                               m (intermediate)..
                              36 airguns (6,600
                               in\3\), 6 m tow
                               depth, 50 m
                               (shallow)..
Receiver Specs..............  Calibration           Calibration
                               hydrophone buoy:.     hydrophone buoy and
                              Shallow--spar buoy     multi-channel
                               anchored on the       seismic hydrophone
                               seafloor,             array, both in
                               hydrophone at 18 m.   shallow water.
                              Intermediate--spar
                               buoy not anchored,
                               hydrophone at 18 m
                               and 500 m..
                              Deep--spar buoy not
                               anchored,
                               hydrophone at 18 m
                               and 350 to 500 m..
Data Validation.............  Curve based on best   NA.
                               fit line, 95% of
                               received levels
                               fall below curve.
Empirical Radii Appropriate   36 airguns            36 airguns
 for Sampling Maximum          (shallow)--Yes,       (shallow)--Yes,
 Received Level.               appropriate for       appropriate for
                               mitigation modeling.  mitigation radii.
                              36 airguns
                               (intermediate)--No,
                               does not sample
                               maximum received
                               levels > 500 m..
                              36 airguns (deep)--
                               No does not sample
                               maximum received
                               levels > 500 m.
Received Level Metric         90% of cumulative     SEL contours (150,
 Presented.                    energy rms levels     170, and 180).
                               and SEL.             Diebold et al.
                              Tolstoy et al.         (2010) modeled data
                               (2009) empirical      from Figure 2.
                               data from Table 1.
RMS vs. SEL Offsets.........  36 airguns in deep    NA.
                               water--~14 dB
                               offset, rms > SEL.
                              36 airguns in
                               shallow water--8 dB
                               offset, rms > SEL.
Differences between the       Because the deep-     The current
 Previous and Current          water calibration     propagation model
 Approaches.                   buoy only sampled     uses the maximum
                               received levels at    SPL values shown in
                               a constant depth of   Figure 2 in Diebold
                               500 m, it is not      et al. (2010).
                               appropriate to use    These values along
                               the empirical deep-   the diagonal
                               water data from       maximum SPL line
                               Tolstoy et al.        connect the points
                               (2009) to derive      where the isopleths
                               mitigation radii.     attain their
                               This is due to the    maximum width
                               buoy not capturing    (providing the
                               the intersect of      maximum distance
                               all the SPL           associated with
                               isopleths at their    each sound level).
                               wildest point from    These distances
                               the sea surface       will differ from
                               down to ~2,000 m.     values obtained
                               However, the          along the Tolstoy
                               received levels       et al. (2009) data
                               (i.e., direct         shown in Table 1
                               arrivals and          which derives radii
                               reflected and         from the 500 m
                               refracted arrivals)   constant depth
                               are in agreement      line.
                               with the current
                               propagation model.
------------------------------------------------------------------------

    Comment 3: The Commission states that in 2011, NSF and USGS modeled 
sound propagation under various environmental conditions in their PEIS. 
L-DEO and NSF (in cooperation with Pacific Gas and Electric Company 
[PG&E]) also used a similar modeling approach in the recent IHA 
application and associated EA for a seismic survey of Diablo Canyon in 
California (77 FR 58256). These recent examples indicate that L-DEO, 
NSF, and related entities are able to implement the recommended 
approach, if required to do so by NMFS. The Commission understands the 
constraints imposed by the current budgetary environment, but notes 
that other agencies that contend with similar funding constraints 
incorporate modeling based on site-specific parameters. USGS, L-DEO, 
NSF and

[[Page 52127]]

related entities should be held to that same standard. NMFS recently 
indicated that it does not, and does not believe it is appropriate to, 
prescribe the use of any particular modeling package (79 FR 38499). The 
Commission agrees that NMFS should not instruct applicants to use 
specific contractors or modeling packages, but it should hold 
applicants to the same standard, primarily one in which site- and 
operation-specific environmental parameters are incorporated into the 
models.
    Response: PG&E submitted an IHA application to NMFS and the U.S. 
Fish and Wildlife Service for the Central Coastal California Seismic 
Imaging Project in 2012. The IHA application included a report of 
acoustic propagation modeling conducted by Greeneridge Sciences, Inc., 
sponsored by Padre Associated, Inc., to estimate received sound 
pressure level radii for airgun pulses operating off central California 
in the vicinity of the Diablo Canyon Nuclear Power Plant. A wave-theory 
model and precise waveguide parameters that describe sound reflections 
and refractions at the ocean surface, seafloor, and water column were 
used to accurately model sound transmission in the ocean. As the action 
proponent, PG&E funded the seismic survey and related environmental 
compliance documents (e.g., IHA application, Environmental Assessment, 
etc.). NSF, as the owner of the Langseth, served as the federal nexus 
for the ESA section 7 consultation and need for the preparation of the 
NEPA document. L-DEO is the operator of the Langseth and often applies 
for IHAs for NSF-funded seismic surveys conducted for scientific 
research purposes.
    There are many different modeling products and services 
commercially available that applicants could potentially use in 
developing their take estimates and analyses for MMPA ITAs. These 
different models range widely in cost, complexity, and the number of 
specific factors that can be considered in any particular modeling run. 
NMFS does not, and does not believe that it is appropriate to, 
prescribe the use of any particular modeling package. Rather, each 
applicant's approach is evaluated independently in the context of their 
activity. In cases where simpler models are used and there is concern 
that a model might not capture the variability across a parameter(s) 
that is not represented in the model, conservative choices are often 
made a certain decision points in the model to help ensure that modeled 
estimates are buffered in a manner that would not result in the agency 
underestimating the number of takes or extend of effects. In this case, 
results have shown that the L-DEO's model reliably and conservatively 
estimates mitigation radii in deep water. The observed sound levels 
from the field measurements fell almost entirely below L-DEO's 
estimated mitigation radii for deep water (Diebold et al., 2010). Based 
on the these empirical data, which illustrate the model's conservative 
exposure estimates across two sites, NMFS finds that L-DEO's model 
effectively estimates sound exposures.
    NMFS encourages applicants to incorporate modeling based on site-
specific and operation-specific parameters in their IHA applications, 
whenever possible, but it is unrealistic to hold applicants to this 
same standard in IHA applications and/or NEPA documents (EAs and EISs) 
as activities may vary in their scope and level of anticipated impacts, 
and applicants may have varying funding and resource constraints. 
However, it is still incumbent upon NMFS to take the uncertainty that 
comes along with varying models into consideration in both the analysis 
of effects and the consideration of mitigation measures. In this case, 
as described elsewhere in this section, we have considered the 
uncertainty associated with the applicant's model and have determined 
that it does not change either our findings regarding the anticipated 
level and severity of impacts on marine mammals or our conclusion that 
the mitigation measures required provide the means of effecting the 
least practicable impact on the affected species or stocks and their 
habitat.
    Of broader note, NMFS is currently pursuing methods (that include 
site-specific components) to allow us to better cross-check isopleth 
and propagation predictions submitted by applicants. Using this 
information, we could potentially recommend modifications to take 
estimates and/or mitigation zones, as appropriate.
    Comment 4: The Commission states that NMFS indicated that based on 
empirical data (which illustrate the L-DEO's model's conservative 
exposure estimates for the Gulf of Mexico and preliminarily off 
Washington), it found that L-DEO's model effectively estimates sound 
exposures or number of takes and represents the best available 
information for NMFS to reach its determinations for the IHA. However, 
for the survey off New Jersey, NMFS increased the exclusion zone radii 
by a factor of 50% (equivalent to approximately a 3 dB difference in 
received level at the zone edge) to be additionally precautionary (79 
FR 38499). The Commission questions, if NMFS really believes the L-DEO 
model is based on best available science, why it then extended the 
exclusion zones to be precautionary and if NMFS felt the need to be 
precautionary and extend the exclusion zones, why it did not then also 
extend the buffer zones and thus the estimated numbers of takes of 
marine mammals.
    Response: NMFS increased the exclusion zones for the L-DEO seismic 
survey off New Jersey due to site-specific considerations. Crone et al. 
(2013) confirmed that the shallow water zones in L-DEO's model were 
conservative in previous shallow water seismic surveys in the northeast 
Pacific Ocean. However, the model had limited ability to capture the 
variability resulting from site-specific factors present in the marine 
environment offshore New Jersey. In light of those limitations, and in 
consideration of the practicability of implementation in that 
particular case NMFS recommended a more conservative approach to 
mitigation specifically tailored to the New Jersey seismic survey that 
required L-DEO to enlarge the exclusion zones. As noted previously, 
though there are limitations with the L-DEO model, NMFS believed that 
L-DEO was able to adequately estimate take for the New Jersey seismic 
survey and had no reason to believe that potential variation in site-
specific parameters would result in differences that would change our 
analysis of the general level or severity of effects or our necessary 
findings. However, in consideration of the practicability of doing so, 
we were able to precautionarily add a buffer to the mitigation zone.
    The same site-specific considerations do not exist in this case. 
The current seismic survey will occur entirely in deep water depths 
(greater than 1,000 m). The L-DEO model reasonably predicts mitigation 
zones in deep water (verified by Crone et al., 2013 and Diebold et al., 
2010). Diebold et al. reported that the observed sound levels from the 
field measurements during the 2007/2008 calibration studies in the Gulf 
of Mexico fell almost entirely below the predicted mitigation radii 
curve for deep water. L-DEO has shown that its model reasonably 
predicts mitigation zones in deep water (verified by Crone et al., 2013 
and Diebold et al., 2010). Therefore, NMFS did not recommend expanding 
the exclusion zones for this seismic survey because the model 
conservatively predicts received sound levels as a function of distance 
from a particular airgun array configuration in deep water.

[[Page 52128]]

    Comment 5: COA and NRDC et al. states that the potential impacts on 
marine species from sound-producing sources other than airguns were not 
meaningfully evaluated. The commenters state that a 12 kHz multi-beam 
echosounder operated by an ExxonMobil survey vessel off the coast of 
Madagascar was implicated by an independent scientific review panel in 
the mass stranding of melon-headed whales in 2008. Commenters state 
that a beaked whale stranding observed in the action area of a 2002 L-
DEO seismic survey in the Gulf of California may have been linked to 
the use of this technology as well. COA states that based on the 
correlation between these previous stranding events and the use of 
multi-beam echosounder technology, it is imperative that NMFS fully 
assess the potential for this source to impact marine mammals both on 
its own and with the operation of the airgun array.
    Response: NMFS disagrees with the commenter's assessment that the 
potential impacts on marine species from sound-producing sources other 
than airguns, was not meaningfully evaluated. NMFS assessed the 
potential for the operation of the multi-beam echosounder and sub-
bottom profiler to impact marine mammals, both on their own and 
simultaneously with the operation of the airgun array. NMFS assumes 
that, during simultaneous operations of the airgun array and the other 
sources, any marine mammals close enough to be affected by the multi-
beam echosounder and sub-bottom profiler will 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 
multi-beam echosounder and sub-bottom profiler given their 
characteristics (e.g., narrow, downward-directed beam) and other 
considerations described previously in the notice of the proposed IHA 
(79 FR 35642, June 23, 2014). Such reactions are not considered to 
constitute ``taking'' (NMFS, 2001). Therefore, USGS provided no 
additional allowance for animals that could be affected by sound 
sources other than airguns and NMFS has not authorized take from these 
other sound sources. NMFS's notice of the proposed IHA (79 FR 35642, 
June 23, 2014) states that the multi-beam echosounder and sub-bottom 
profiler will not operate during transits at the beginning and end of 
the planned seismic survey; therefore, NMFS does not expect any 
potential impacts from these sound sources in shallow water or coastal 
areas.
    Regarding the 2008 stranding of melon headed whales in Madagascar 
referenced by commenters, the use of a high-power (source level 236 to 
242 dB) 12 kHz multi-beam echosounder was deemed the most plausible and 
likely behavioral trigger that caused a large group of melon-headed 
whales to leave their typical habitat and then ultimately strand as a 
result of secondary factors such as malnourishment and dehydration. In 
addition to the source level associated with that particular multi-beam 
echosounder, its movement pattern (i.e., directed manner down the shelf 
break within a channel) contributed to displacing this species, via an 
avoidance response, from its typical deep-water habitat to the shallow-
water lagoon system where the stranding occurred. This USGS seismic 
survey is not being operated in this manner. This species was also 
identified as a particularly behaviorally sensitive species to 
anthropogenic sound (i.e., not all species expected to respond in the 
same manner as this species) and a ``confluence of factors'' may have 
caused this group of whales to orient in a manner relative to the 
multi-beam echosounder that caused an avoidance response leading to an 
out-of-habitat area (i.e., not every exposure situation where this type 
of source is used is expected to result in a similar behavioral 
response and/or outcome). Furthermore, behavioral responses can be 
quite complex and variable, depending on a multitude of factors, 
including context (Ellison et al., 2011).
    Regarding the 2002 stranding in the Gulf of California, the multi-
beam echosounder system was on a different vessel, the R/V Maurice 
Ewing (Ewing), which is a vessel no longer operated by L-DEO. Although 
COA and NRDC et al. suggests that the multi-beam echosounder system or 
other acoustic sources on the Ewing may have been associated with the 
2002 stranding of 2 beaked whales, as noted in Cox et al. (2006), 
``whether or not this survey caused the beaked whales to strand has 
been a matter of debate because of the small number of animals involved 
and a lack of knowledge regarding the temporal and spatial correlation 
between the animals and the sound source.'' As noted by Yoder (2002), 
there was no scientific linkage to the event with the Ewing's 
activities and the acoustic sources being used.
    As noted by Hildebrand (2006), ``the settings for these stranding 
(e.g., Canary Islands, Greece, Bahamas, etc.) are strikingly 
consistent: An island or archipelago with deep water nearby, 
appropriate for beaked whale foraging habitat. The conditions for mass 
stranding may be optimized when the sound source transits a deep 
channel between two islands, such as in the Bahamas, and apparently in 
the Madeira incident.'' The activities planned for the USGS seismic 
survey are in remote deep water, far from any land mass and islands, 
and do not relate at all to the environmental scenarios noted by 
Hildebrand (2006) as being consistent settings for other mass 
strandings of beaked whales.

MMPA Concerns

    Comment 6: COA state that NMFS must ensure that the IHA complies 
with the MMPA and requests that NMFS deny the IHA based on their 
opinion that the potential impacts to marine mammals are incompatible 
with the prohibitions of the MMPA and that the take would be more than 
negligible.
    Response: NMFS disagrees with the commenters' assessment. Section 
101(a)(5)(D) of the MMPA directs NMFS to allow, upon request, the 
incidental taking by harassment of small numbers of marine mammals for 
periods of not more than one year by U.S. citizens who engage in a 
specified activity within a specific geographic region if certain 
findings are made and a notice of a proposed IHA is provided to the 
public for review. In order to grant an IHA under section 101(a)(5)(D) 
of the MMPA, NMFS must find that the taking by harassment of marine 
mammal species or stocks will have a negligible impact on such species 
or stocks and will not have an unmitigable adverse impact on the 
availability of such species or stocks for taking for subsistence uses. 
Where applicable, the IHA must also prescribe the permissible methods 
of taking by harassment pursuant to the activity, and other means of 
effecting the least practicable impact on such species or stocks and 
their habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance. NMFS followed all 
applicable legal standards and made all relevant findings before 
issuing an IHA to USGS under section 101(a)(5)(D) of the MMPA.
    As described in the notice for the proposed IHA (79 FR 35642, June 
23, 2014) and this document, USGS requested that NMFS issue an IHA to 
take small numbers of marine mammals by Level B harassment only 
incidental to conducting a seismic survey within a specific geographic 
area (see ``Summary of Request''). Based on the best scientific 
information available, NMFS expect that USGS's activities would result 
in take by Level B harassment

[[Page 52129]]

only in the form of behavioral modifications during the period of the 
USGS's active airgun operations. Due to the nature, degree, and context 
of Level B harassment anticipated and described in the notice of the 
proposed IHA (79 FR 35642, June 23, 2014) and this document, NMFS does 
not expect the activity to impact rates of annual recruitment or 
survival for any affected species or stock, particularly given the 
required mitigation and monitoring measures that would minimize impacts 
to marine mammals (see ``Negligible Impact'' section). NMFS has 
determined that the required mitigation and monitoring measures 
(described in the notice for the proposed IHA [79 FR 35642, June 23, 
2014], and included within the final IHA), provide the means of 
effecting the least practicable impact on marine mammal species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance (see ``Mitigation'' 
section). There are not relevant subsistence uses of marine mammals 
implicated by this action.
    Based on the analysis of the likely effects of the specified 
activity on marine mammals and their habitat contained within the 
notice of the proposed IHA (79 FR 35642, June 23, 2014) this document, 
and the USGS's EA, and taking into consideration the implementation of 
the required mitigation and monitoring measures, NMFS finds that the 
USGS seismic survey will have a negligible impact on such species or 
stocks and will not have an unmitigable adverse impact on the 
availability of such species or stocks for taking for subsistence uses. 
NMFS has therefore issued an IHA to USGS to take small numbers of 
marine mammals by Level B harassment only for a period less than one 
year. NMFS has complied with the MMPA and disagrees with the 
commenter's assessment that the potential impacts to marine mammals 
from USGS's seismic survey are incompatible with the prohibitions of 
the MMPA and that the take would be more than negligible.
    Comment 7: COA states that NMFS's take estimates for marine mammals 
which no population or stock data are available are speculative and may 
be significant underestimations. COA states that it is not clear how 
these takes were assigned and what, if any, measures would be taken 
during the seismic survey if it is determined that take numbers for 
these animals were significantly miscalculated.
    Response: Although no known current regional population or stock 
abundance estimates for the northwest Atlantic Ocean are available for 
the Fraser's, spinner, and Clymene dolphins, or the Bryde's, melon-
headed, pygmy killer, false killer, and killer whales, limited OBIS-
SEAMAP sightings data exist for these species within or adjacent to the 
action area. Even where the limited number of sightings suggests that 
density is very low and encounters less likely, for any species with 
OBIS-SEAMAP sightings data within or adjacent to the action area, 
including both species of marine mammals that did not have density 
model outputs within the SERDP/NASA/NOAA and OBIS-SEAMAP database 
(i.e., humpback whale [summer], Bryde's whale, sei whale, blue whale, 
northern bottlenose whale, Atlantic white-sided dolphin, Fraser's 
dolphin, spinner dolphin, Clymene dolphin [summer], melon-headed whale, 
pygmy killer whale, false killer whale, and killer whale) and species 
with density outputs that did not extend into the planned study area at 
all (i.e., sei whale), NMFS believes it is wise to include coverage for 
potential takes. Generally, to quantify this coverage, NMFS assumed 
that USGS could potentially encounter one group for each species during 
each of the seismic survey legs (recognizing that interannual variation 
and the potential presence of ephemeral features could drive differing 
encounter possibilities in the two legs), and NMFS thinks it is 
reasonable to use the average (mean) groups size (weighted by effort 
and rounded up) to estimate the take from these potential encounters. 
The mean group size were determined based on data reported from the 
Cetacean and Turtle Assessment Program (CeTAP) surveys (CeTAP, 1982) 
and the Atlantic Marine Assessment Program for Protected Species 
(AMAPPS) surveys in 2010, 2011, 2012, and 2013. Because we believe it 
is unlikely, we do not think it is necessary to assume that the largest 
group size will be encountered. USGS proposed this same approach in 
their IHA application, and is aware that they will not be covered in 
the unlikely event that a larger group is ensonified above 160 dB.
    PSOs based on the vessel 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 would be 
used to estimate numbers of animals potentially taken by harassment. If 
the estimated numbers of animals potentially taken by harassment 
approach or exceed the number of authorized takes, USGS will have to 
re-initiate consultation with NMFS under the MMPA and/or ESA.
    Comment 8: The Commission states that in estimating the numbers of 
potential takes for the proposed IHA, USGS used density data from the 
Ocean Biogeographic Information System Spatial Ecological Analysis of 
Megavertebrate Populations (OBIS-SEAMAP), specifically data originating 
from Navy Operating Area Density Estimates (NODE). USGS considered 
those estimates to be the best available data. However, those data 
apply only to the U.S. EEZ, which comprises only 20 percent of the 
proposed action area in 2014 and 10 percent in 2015. It is unclear if 
USGS assumed the densities in areas outside the U.S. EEZ to be 0, if it 
applied the densities estimated for waters within the EEZ to those 
other areas, or if it did some permutation of those two methods. In any 
case, the densities could have been underestimated.
    Although NMFS indicated in the notice of the proposed IHA (79 FR 
35642, June 23, 2014) that the OBIS-SEAMAP data were determined to be 
the best available information for density data, the Commission 
understands that NMFS subsequently determined that the data from the 
Navy's Atlantic Fleet Training and Testing Navy Marine Species Density 
Database (AFTT NMSDD) are superior and are now considered the best 
available. Therefore, the Commission understands that NMFS intends to 
use the AFTT NMSDD data to re-estimate the numbers of marine mammals 
that could be taken during the seismic survey. The Commission agrees 
that the AFTT NMSDD data are preferable and should be used to re-
estimate the numbers of takes for all marine mammal species and used 
for the analyses required under both the MMPA and the ESA. Furthermore, 
the Commission recommends that the same methods to be used to determine 
the densities for the analyses conducted under the MMPA and ESA.
    Response: NMFS's Office of Protected Resources, Permits and 
Conservation Division, has carefully considered both the SERDP-SDSS and 
NMSDD data to determine which is more appropriate for calculating take 
estimates. NMFS considers the NMSDD dataset useful in predicting marine 
mammal density and distribution in the open ocean where better data are 
unavailable. However, for this study and for the reasons described 
below, NMFS's Office of Protected Resources, Permits and Conservation 
Division has determined that applying the SERDP-SDSS finer-scale 
density estimates from the immediately adjacent

[[Page 52130]]

and more similar areas is the more accurate approach. The survey study 
area extends from Georges Bank southward to Blake Ridge in the 
northwest Atlantic Ocean. The entire study area encompasses 543,601 
km\2\ (158,488.7 nmi\2\) and covers portions of the continental slope, 
continental rise, and abyssal plain. Approximately 40% of the study 
area is within the U.S. EEZ (``study area'' means the polygon drawn 
around the two legs of the survey). For the 2014 leg, USGS planned a 
total of 3,165 km (1,709 nmi) of tracklines within the action area. Of 
those 442.6 km (239 nmi) (14%) are within the U.S. EEZ. For the 2015 
leg, USGS planned a total of 3,115 km (1,682 nmi) of tracklines within 
the action area. Of those 558.2 km (301.4 nmi) (18%) are within the 
U.S. EEZ. There are no tracklines located within the continental shelf 
and approximately 99% of the tracklines are located outside the 
continental shelf. Less than 0.5% of the tracklines are within the 
continental slope. For both years 89% of the seismic survey's 
tracklines will occur within the abyssal plain, 11% within the 
continental rise, and less than 1% of the tracklines will occur within 
the continual shelf.
    The USGS determined that they could obtain and analyze the best 
available information for density data from the SERDP-SDSS Marine 
Animal Mapper online system. The SERDP-SDSS model outputs provide 
color-coded maps of cetacean density as well as maps that depict the 
precision of the models. The NMFS, Office of Protected Resources, 
Permits and Conservation Division, considers the NODES models from the 
SERDP-SDSS used here at Tier 1 data. These models accurately predict 
density within the continental shelf, slope, and rise based on fine-
scale spatially relevant (e.g., collected within the immediate 
vicinity) marine mammal survey data and environmental factors. NMFS, 
Office of Protected Resources, Permits and Conservation Division, 
considers it as a robust dataset to estimate densities with the least 
amount of uncertainty.
    Generally, the NMSDD maps for the study area in question have shown 
much higher densities of marine mammals adjacent to the U.S. EEZ line 
compared to the SERDP-SDS prediction. The NMSDD predicts density 
information for species outside the U.S. EEZ using two additional 
sources of information based on habitat suitability models, the Sea 
Mammal Research Unit Limited (SMRU Ltd.), University of St. Andrews, 
Scotland Global Density Models (SMRU Ltd., 2012) and the Kaschner model 
(2006). The Navy applied the SMRU Ltd. model to areas or seasons where 
the NODE density spatial model data contained in SERDP-SDSS were not 
available. The Kaschner model (2006) predicts the average annual 
geographical ranges of marine mammal species on a global scale. The 
model uses a Relative Environmental Suitability (RES) model that 
synthesizes general, qualitative observations about the spatial and 
temporal relationships between four environmental factors (depth, sea 
surface temperature, distance to land, and mean annual distance to ice 
edge) and the worldwide distribution of a particular species. The 
Kaschner model is not as robust (and in some cases unsuccessful) in 
predicting spatially-relevant patterns of cetacean distribution at a 
finer scale because the model is parameterized for a broader region and 
scale. Thus, in many cases, predicted distributions may not correspond 
well with the known distribution of particular species (Calabrese et 
al., 2014; Redfern et al., 2006; Williams et al., 2014), leading to 
inaccurate extrapolations (i.e., including areas that are not known to 
be habitat) that do not comport with the expected distribution of a 
particular species. The Navy considered this model as tertiary to the 
NODE density spatial model data contained in SERDP-SDSS and secondary 
to the SMRU Ltd. data. They only applied the Kaschner model data to 
areas where NODE or SMRU Ltd. data were available.
    The SERDP-SDSS model outputs for density estimates do not extend 
beyond the U.S. EEZ. Thus data for 60% of the USGS's study area are not 
available in the online system. However, the USGS used the system to 
extract the mean density (animals per square kilometer) for marine 
mammals within 40% of the study area that is within the U.S. EEZ. 
Because the SERDP-SDSS provides fine-scale predictions with greater 
certainty over the continental shelf, slope, and rise, NMFS, Office of 
Protected Resources, Permits and Conservation Division, feels that is 
reasonable to extrapolate the density estimates from the coastal and 
shelf areas to areas further offshore (i.e., continental rise and 
abyssal plain zone). Generally, we would expect higher densities of 
marine mammal over the continental shelf, slope, and rise. Thus, 
extrapolating these densities to the offshore study area seems the most 
reasonable approach given the datasets available. In relying on basic 
ecological principles, NMFS, Office of Protected Resources, Permits and 
Conservation Division, would expect lower densities of marine mammals 
within the study area that extends beyond the U.S. EEZ over the 
continental rise and abyssal plain in contrast to the results shown in 
NMSDD.
    Comment 9: NRDC et al. and the Commission state that NMFS made 
erroneous small numbers and negligible impact determinations. They 
state that the MMPA clearly prohibits agencies from taking marine 
mammals on the high seas, and since the take prohibition applies 
outside the EEZ as well as in U.S. waters, NMFS must make a negligible 
impact and small numbers determination to authorize take for the 
populations in both the U.S. EEZ and on the high seas outside the U.S. 
EEZ. NRDC et al. and the Commission also state that notice for the 
proposed IHA suggests that NMFS is authorizing the take of 43.44% of 
the pantropical spotted dolphin stock, which is not a small number.
    Response: NMFS agrees that the MMPA applies outside of the U.S. EEZ 
on the high seas. NMFS considered takes outside of the U.S. EEZ both in 
our negligible impact and small numbers determinations. NMFS makes it 
small numbers determination based on the number of marine mammals that 
would be taken relative to the populations of the affected species or 
stocks. NMFS's take estimates for the current survey are based on a 
consideration of the number of marine mammals that could be harassed by 
seismic operations within the entire seismic survey area, both within 
and outside of the U.S. EEZ. Given that the take estimates were 
calculated for the entire survey area, NMFS concluded that a portion of 
the takes would take place within the U.S. EEZ and the remainder would 
take place outside of the U.S. EEZ. As explained previously in this 
document, approximately 80% of the survey tracklines in 2014 and 
approximately 90% of the survey tracklines in 2015 are outside of the 
U.S. EEZ. Therefore, as the small numbers determination section in the 
notice for the proposed IHA explained, NMFS apportioned 10 to 20% of 
the total authorized takes to the U.S. EEZ in order to make its small 
numbers determination for the affected U.S. EEZ stocks. Table 6 in this 
document has been updated to reflect this apportionment. All of the 
takes that NMFS expects to occur within the U.S. EEZ represent a small 
number relative the affected U.S. EEZ stocks.
    For species for which regional abundance data exists (North 
Atlantic right whale, humpback whale, minke while, sei whale, fin 
whale, blue whale, sperm whale, Atlantic white-sided dolphin, short-
finned pilot whale, long-

[[Page 52131]]

finned pilot whale, Northern bottlenose whale, and harbor porpoise), 
Table 4 of the notice for the proposed IHA clearly reflected that the 
estimated take for the entire survey area represented a small number 
relative to the regional populations. For species for which only stock 
abundance data exists (pygmy sperm whale, dwarf sperm whale, Cuvier's 
beaked whale, Mesoplodon, bottlenose dolphin, Atlantic spotted dolphin, 
pantropical spotted dolphin, striped dolphin, short-beaked common 
dolphin, rough-toothed dolphin, Risso's dolphin), NMFS concluded that 
if the authorized take represents a small number of the U.S. EEZ stock, 
it will also represent a small number of the greater regional 
population, based on the larger and wider ranging populations expected 
in the high seas. This conclusion is supported by the fact that, for 
the species with both regional and stock-specific abundance 
populations, the regional abundance is on the order of five to twenty 
times higher than the abundance of the stock. We have clarified the 
small numbers determination in this document accordingly.
    With respect to the pantropical spotted dolphin, Table 4 in the 
notice for the proposed IHA indicated that 43% of the stock would be 
taken. However, this number represents the total authorized take for 
the entire survey area as compared to the population of the U.S. EEZ 
stock. The small numbers section explained that to determine whether 
the authorized take would be a small number of the affected U.S. EEZ 
stock, NMFS apportioned 10 to 20% of the authorized take to the U.S. 
EEZ, as described above, and determined that approximately 6.5% percent 
of the U.S. EEZ stock would be taken. The remainder of the takes would 
occur outside the U.S EEZ. Although no regional abundance estimate 
exists for the pantropical spotted dolphin, it is one of the most 
abundant cetaceans on the globe and occurs in all tropical to warm 
temperate waters between 40[deg] North and South (Folkens, 2002). 
Therefore, we are confident that the authorized take represents a small 
number compared to the greater regional Atlantic pantropical spotted 
dolphin population that occurs outside of the U.S. EEZ.
    Comment 10: The Commission states that under section 
101(a)(5)(D)(iii) of the MMPA an IHA can be issued only after notice in 
the Federal Register and opportunity for public comment. However, that 
public review opportunity is meaningful only if the proposed IHA 
contains accurate information and the relevant analyses. If, subsequent 
to the publication, substantive changes are made to the underlying 
information or NMFS's analyses, re-publication with a new opportunity 
to comment is appropriate. In this instance, it appears that NMFS's 
published analyses were not based on the best available information and 
that it may have significantly underestimated the likely numbers of 
takes for at least some of the marine mammal species and stocks that 
occur in the proposed action area. The Commission recommends that NMFS 
publish a revised proposed IHA in the Federal Register with updated 
estimated numbers of takes and small numbers and negligible impact 
analyses to provide a more informed public comment opportunity. 
Further, the Commission recommends that, to the extent possible, NMFS 
strive to identify and incorporate any substantive changes that might 
be made in a proposed IHA prior to publication in the Federal Register.
    Response: NMFS's analysis in this document is based on the best 
available information and NMFS does not believe that the estimated 
number of takes for the marine mammal species and stocks in the action 
area have been significantly underestimated. Please see the response to 
comment 8 for NMFS's rationale regarding the careful consideration of 
both the SERDP-SDSS and NMSDD to determine which is more appropriate 
for using density data and calculating take estimates. In the case of 
marine mammals species with OBIS-SEAMAP sightings within or adjacent to 
the action area and expected to be encountered, where density data was 
limited or unavailable, NMFS updated the mean group sizes that were 
determined based on data reported from the Cetacean and Turtle 
Assessment Program (CeTAP) surveys (CeTAP, 1982) as well as the reports 
from the Atlantic Marine Assessment Program for Protected Species 
(AMAPPS) surveys in 2010, 2011, 2012, and 2013. However, for most of 
the marine mammal species, the estimated number of takes did not change 
between the notice of the proposed IHA (79 FR35642, June 23, 2014) and 
the final IHA. The small numbers and negligible impact analyses and 
determinations made by NMFS still remain accurate. NMFS strives to 
identify and incorporate any substantive changes before publishing a 
notice of proposed IHA in the Federal Register, but may need to make 
substantive changes based on information and comments received during 
the 30-day public comment period. NMFS acknowledges the Commission's 
recommendation, but will not be publishing a notice of a revised 
proposed IHA in the Federal Register.

Mitigation

    Comment 11: NRDC et al. states that time and area restrictions 
designed to protect high-value habitat are one of the most effective 
means to reduce the potential impacts of noise and disturbance. They 
also state that the proposed IHA does not consider any areas for 
closure, trackline avoidance or seasonal planning for any species of 
marine mammals.
    Response: NMFS disagrees with NRDC et al.'s assessment. NMFS used 
the Navy's NODE model for determining the density data of marine mammal 
species (where it was available) and calculating estimated take 
numbers. USGS has indicated that they plan on avoiding banks, canyons, 
seamounts, and North Atlantic right whale critical habitat. NMFS was 
not able to identify any other important habitat areas of specific 
importance to marine mammals from this dataset that are appropriate for 
avoidance or time-area restrictions. Further, the seismic survey's 
planned tracklines, which are widespread over a large geographic area, 
combined with the transiting vessel and airgun array, make time-area 
restrictions and avoiding specific habitat areas impractical and likely 
would not provide significant reduction in potential impacts from 
underwater sound or sufficient conservation benefits for this specific 
project. NMFS notes that areas for closure, trackline avoidance, or 
seasonal planning were also considered in the USGS EA and not included 
in the proposed IHA as they were deemed unnecessary or not practicable. 
For responses to the specific time-area restrictions NRDC et al. 
suggest, see the responses below in this section.
    Concerning the avoidance of marine mammals through the modification 
of tracklines, the IHA states that the Langseth should alter speed or 
course during seismic operation if a marine mammal, based on its 
position and relative motion, appears likely to enter the relevant 
exclusion zone. If speed or course alteration is not safe or 
practicable, or if after alteration the marine mammal still appears 
likely to enter the exclusion zone, further mitigation measures, such 
as a power-down or shut-down, shall be taken. The USGS EA, which NMFS 
adopted, also considers that slight track adjustments are possible to 
avoid fisheries conflicts: ``minimizing potential adverse effects on 
fisheries may be accomplished by adjusting tracklines and communicating

[[Page 52132]]

with fishermen about respective locations of vessels, equipment, and 
rate of travel or drift.'' Because of limited ship maneuverability, 
trackline adjustments must also be done to ``maintain safety and avoid 
entanglement.''
    Concerning seasonal planning, seasonal (four seasons where 
available) distributions of marine animals are incorporated into the EA 
through the descriptions presented in chapter 3. A complete table of 
the seasonal distributions of potentially affected marine mammal 
species is given in the IHA application (Table 3). The EA also 
evaluated as an alternative conducting the seismic survey at a 
different time of year. Weather conditions in the Atlantic Ocean and 
ship schedules constrain the possible survey time window to May through 
September. In addition, scheduling the survey in mid-summer when 
daylight hours are maximized and sea states are generally minimal 
facilitates observations of marine wildlife.
    Comment 12: NRDC et al. state that because of the incredibly rich 
diversity of species that congregate around Georges Bank throughout the 
year and, most heavily, during the summer months, the seismic survey 
should be prohibited from entering Georges Bank or the slope waters off 
Georges Bank, and the survey tracklines should be designed to ensure a 
buffer zone minimally sufficient to minimize potential behavioral 
impacts on na[iuml]ve deep-diving whales and disruption of 
communication with baleen whales.
    Response: Three lines of the combined 2014 and 2015 tracklines are 
near Georges Bank. The shallow ends of these three tracklines are in 
2,500 to 2,600 m (8,202.1 to 8,530.2 ft) water depth, or deeper than 
the ``slope waters'' that NRDC et al. reference. These tracklines are 
on the upper rise of the continental margin. The distance from the 
landward (turning) ends of the tracklines in 2015 to the shelf-slope 
break on Georges Bank are approximately 50 km (27 nmi, eastern) and 70 
km (37.8 nmi, western); thus, no survey tracklines are actually within 
Georges Bank. The trackline closest to the eastern end of Georges Bank 
and the New England seamounts will image the Munson-Nygren-Retriever 
submarine landslides and will provide a comparison to understand why 
one region fails and another does not. Both of the tracklines that come 
closest to Georges Bank will address the hazards objectives of the 
planned seismic survey. The portion of the seismic survey near Georges 
Bank represents a small part of the planned action area.
    Comment 13: NRDC et al. states that to the extent that survey 
tracklines cut across the three identified canyons, Oceanographer, 
Gilbert, and Lydonia, USGS should redraw them to avoid overrunning 
these important foraging waters and to ensure a sufficient buffer 
between the trackline and the canyon.
    Response: The seismic survey tracklines south of Georges Bank are 
intentionally planned by USGS to avoid Oceanographer, Gilbert, and 
Lydonia canyons. They have been located to address the submarine 
landslide and tsunami hazards objective of the project. An important 
part of understanding where and why landslides occur is to also 
understanding where and why they do not occur in the same area. The 
three lines closest to Georges Bank are located away from canyons and 
known landslides in order to understand why one part of the margin 
fails and another does not.
    Oceanographer, Gilbert, and Lydonia canyons are in close proximity 
to each other on the south side of Georges Bank. The Gilbert channel 
merges with the Lydonia channel in approximately 2,800 m (9,186.4 ft) 
water depth. Oceanographer Canyon merges with the Lydonia/Gilber system 
in approximately 3,400 m (11,154.9 ft).
    The distances of the three tracklines on the south side of Georges 
Bank from the Lydonia/Gilbert system are 75, 150, and 150 km (40.5, 81, 
and 81 nmi), respectively. The distances from Oceanographer are 100, 
130, and 130 km (54, 70.2, and 70.2 nmi), respectively. The 160 dB 
buffer zone is 5.78 km (3.1 nmi) on either side of each trackline, 
leaving a generous distance of approximately (69 km [37.3 nmi]) to the 
nearest of Oceanographer, Gilbert, and Lydonia canyons.
    In more general terms, the ensonification zone at the landward ends 
of the three tracklines extends to approximately 2,400 to 2,500 m 
(7,874 to 8,202.1 ft) water depth. The base of the canyon system on the 
upper rise of Georges Bank in this region is in approximately 3,500 m 
(11,842.9 ft) of water. The track distance from 2,500 to 3,500 m is 
approximately 45 km (24.3 nmi), or, for the three tracklines, 
represents approximately 135 km (72.9 nmi) (16 hours of surveying), or 
only two percent of the total planned tracklines. Hence the portion of 
the seismic survey near Georges Bank represents a small part of the 
planned action area. The tracklines have been designed to connect to or 
cross existing data to take advantage of existing data sources. 
Therefore, NMFS disagrees with the recommendation that USGS should 
redraw the tracklines to avoid Oceanographer, Gilbert, and Lydonia 
canyons because the tracklines are not close to these canyons and a 
sufficient buffer exists between these tracklines and the canyons.
    Comment 14: NRDC et al. states that there are several major 
submarine canyons, including Norfolk, Washington, Baltimore, Hudson, 
and Veatch. Because of its established importance as a biologically 
rich foraging ground for numerous species of marine mammals and other 
marine life, NRDC et al. states that the survey line should be redrawn 
to avoid Hudson Canyon. To the extent that other survey tracklines cut 
across these additional identified canyons, NRDC et al. states that 
USGS should redraw them to avoid overrunning these important foraging 
waters and to ensure a sufficient buffer between the trackline and the 
canyon.
    Response: USGS designed the tracklines to avoid Hudson Canyon. The 
trackline referred to by NRDC et al. does not cross the Hudson Canyon 
until well along the downslope channel extension in approximately 4,200 
m (13,779.5 ft) water depth on the continental rise. At the landward 
end, the closest approach between the trackline and Hudson Canyon is 21 
km (11.3 nmi). This is between three and four times the radius of the 
160 dB ensonified area (5.78 km). This trackline was originally laid 
out to connect to an existing scientific borehole (ODP 1073), but was 
shortened to connect to existing seismic data that allow for an 
acceptable tie to the well. Hence the seismic survey was modified in an 
effort to avoid collecting new data over existing data. The scientific 
borehole represents an important location for correlating and dating 
units for understanding landslide occurrence.
    Of the five remaining tracklines in the mid-Atlantic region, four 
are more than 300 km (162 nmi) from the shelf-slope break and 
associated canyons. The fifth and southernmost line is south of Cape 
Hatteras, where canyons are not well developed. USGS and NMFS estimate 
the closest canyon, Pamlico Canyon, to this fifth trackline is 
approximately 200 km (108 nmi) to the northeast. Therefore, NMFS 
disagrees with the recommendation that USGS should redraw the 
tracklines to avoid overrunning these foraging waters and to ensure a 
sufficient buffer between the trackline and the canyons.
    Comment 15: NRDC et al. states that the survey tracklines currently 
run across or approach the Bear, Physalia, Mytilus, and Retriever 
seamounts (a seamount chain which may act as a dispersal corridor to 
help species to cross the Atlantic). NRDC et al. states that the 
seismic survey tracklines

[[Page 52133]]

should be modified and redesigned to avoid the four seamounts in order 
to ensure the least practicable impact on marine mammals and should 
include a buffer zone to minimize marine mammal take.
    Response: Although the NRDC et al. comment only mentions the four 
seamounts within the U.S. 200 nmi limit, there are additional seamounts 
beyond 200 nmi, including Picket, Buell, Balanus, and Asterias 
seamounts. The planned tracklines do not run across any of these 
seamounts. Except for the small and deep seamount called Asterias 
seamount, at the seaward end of the tracklines, the closest approach of 
the trackline to any of the eight seamounts is 15 km (8.1 nmi), with 
ranges up to 58 km (31.3 nmi). For the four seamounts inside the U.S. 
200 nmi limit, the distances between the tracks and the base of the 
seamount range from 16.3 to 47 km (8.8 to 25.4 nmi). Given that the 
exclusion zone along the tracklines is 5,780 m (18,963.3 ft), a buffer 
zone already exists between the tracklines and these seamounts.
    NMFS notes that one of the seismic survey's tracklines is within 
6.6 km (3.6 nmi) of Asterias seamount at the seaward end of the 
trackline, but this seamount only rises above the seafloor by 1,200 m 
(3,937 ft) and has a water depth at its top of 3,609 m (11,840.6 ft) 
(ETOPO1). This is much deeper than the four seamounts within the U.S. 
200 nmi limit, which, at their tops, have water depths of 1,112, 2,366, 
2,475, and 2,153 m (3,648.3, 7,762.5, 8,120.1, and 7,063.6 ft), 
respectively (read from digital map released by Andrews et al., 2014). 
Asterias seamount, due to its small size and large depth, is not 
considered a feature that would modify currents and circulation to the 
extent that the larger, shallower seamounts would.
    Therefore, NMFS disagrees with the recommendation that the seismic 
survey tracklines should be modified and redesigned to avoid Bear, 
Physalia, Mytilus, and Retriever seamounts and should include a buffer 
zone to minimize marine mammal take because the tracklines do not cross 
these seamounts and a buffer zone already exists between the tracklines 
and these seamounts.
    Comment 16: NRDC et al. states that in order to protect the North 
Atlantic right whale and comply with the ESA, NMFS must exclude all of 
the North Atlantic right whale's year-round feeding and mating habitat 
areas from the seismic survey and vessel activities. These areas 
include both designated critical habitat as well as areas that have not 
yet been designated as critical habitat, but are known to be important 
habitat.
    Response: NMFS has not excluded the seismic survey from North 
Atlantic right whale designated critical habitat and other habitat 
known to be important to the North Atlantic right whale because the 
planned activities are not in close proximity to these areas. The 
trackline that has the closest approach to the northeast Atlantic Ocean 
designated critical habitat is approximately 190 km (102.6 nmi) from 
the area. The trackline that has the closest approach to the southeast 
Atlantic Ocean designated critical habitat is approximately 519 km 
(280.2 nmi) from the area. The North Atlantic right whale critical 
habitat in the northeast Atlantic Ocean can be found online at: https://
www.nmfs.noaa.gov/pr/pdfs/criticalhabitat/
nrightwhalene.pdf. The North Atlantic right whale 
critical habitat in the southeast Atlantic Ocean can be found online 
at: https://www.nmfs.noaa.gov/pr/pdfs/criticalhabitat/
nrightwhalese.pdf.
    Furthermore, considering the conservation status for the North 
Atlantic right whale, the airguns will be shut-down immediately in the 
unlikely event that this species is observed, regardless of the 
distance from the Langseth. Ramp-up will only begin if the North 
Atlantic right whale has not been seen for 30 minutes.
    Comment 17: NRDC et al. states that marine mammals densities are 
often correlated over medium to large scales with persistent 
oceanographic features, such as currents, productivity, and surface, 
temperature, as well as with concentrations in other marine species, 
such as other apex predators and fish. NMFS should use these other 
areas identifiable through habitat mapping for determining time-area 
restrictions.
    Response: NMFS and USGS used SERDP SDSS model outputs to determine 
density data for marine mammals in the action area. The density data 
was used to estimate take numbers and potential impacts to marine 
mammals. The USGS EA considers current and other metocean information 
as part of the analysis. For example the EA states that ``the region is 
greatly influenced by a prominent ocean current system, the Gulf 
Stream. This is a powerful, warm, and swiftly flowing current that 
flows northward, generally along the shelf edge, carrying warm 
equatorial waters into the North Atlantic (Pickard and Emergy, 1990; 
Verity et al. 1993). Upwelling along the Atlantic coast is both wind-
driven and a result of dynamic uplift (Shen et al., 2000; Lentz et al., 
2003). In addition to the Gulf Stream, currents originating from the 
outflow of both the Chesapeake and Delaware Bays influence the surface 
circulation in the Mid-Atlantic bight. The Chesapeake Bay plume flows 
seaward from the mouth of the bay and then turns south to form a 
coastal jet that can extend as far as Cape Hatteras. Similarly, the 
Delaware Coastal Current begins in Delaware Bay and flows southward 
along the Delmarva Peninsula before entrained into the Chesapeake Bay 
plume.'' In addition, the maps of the seasonal distributions of the 
marine species shows the regions of higher productivity through the 
higher concentrations of animals. Correlating marine mammal densities 
with oceanographic features provides excellent insight into 
environmental analysis for the action area, but it did not lead to 
identifiable areas of concern that would lead NMFS to require and 
implement time-area restrictions in the IHA.
    Comment 18: NRDC et al. state that NMFS should use these other 
areas identifiable through habitat mapping for determining time-area 
restrictions. Researchers have developed at least two predictive models 
to characterize densities of marine mammals in the area of interest: 
The NODE model produced by the Naval Facilities Engineering Command 
Atlantic, and the Duke Marine Lab model produced under contract with 
the Strategic Environmental Research and Development Program. Until 
Duke has produced its new cetacean density model, pursuant to NOAA's 
CetMap program, NRDC et al. state that NMFS should use these sources, 
which represent best available science to identify important marine 
mammal habitat and ensure the least practicable impact.
    Response: NMFS used the Navy's NODE model for determining the 
density data of marine mammal species (where it was available) and 
calculating estimated take numbers. USGS has indicated that they plan 
on avoiding banks, canyons, seamounts, and North Atlantic right whale 
critical habitat. NMFS was not able to identify any other important 
habitat areas of specific importance to marine mammals from this 
dataset that are appropriate for avoidance or time-area restrictions. 
Further, the seismic survey's planned tracklines, which are widespread 
over a large geographic area and designed for the specific objectives 
of this survey, combined with the transiting vessel and airgun array, 
make time-area restrictions and avoiding specific habitat areas 
impractical and likely would not provide significant reduction in 
potential impacts from underwater

[[Page 52134]]

sound or sufficient conservation benefits for this specific project.
    Comment 19: NRDC et al. states that the proposed IHA does not 
adequately consider, or fails to consider at all, a number of other 
reasonable measures that could significantly reduce take from the 
proposed activities.
    Response: In order to issue an IHA under section 101(a)(5)(D) of 
the MMPA, NMFS must set forth the ``permissible methods of taking by 
harassment pursuant to such activity, and other means of effecting the 
least practicable impact on such species or stock and its habitat, 
paying particular attention to rookeries, mating grounds, and areas of 
similar significance.'' NMFS' duty under this ``least practicable 
impact'' standard is to prescribe mitigation reasonably designed to 
minimize, to the extent practicable, any adverse population level 
impacts, as well as habitat impacts. While population-level impacts can 
be minimized only by reducing impacts on individual marine mammals, not 
all takes translate to population-level impacts. NMFS' objective under 
the ``least practicable impact'' standard is to design mitigation 
targeting those impacts on individual marine mammals that are most 
likely to lead to adverse population-level effects. Based on NMFS' 
evaluation of the applicant's proposed measures, as well as other 
measures considered by NMFS or recommended by the public, NMFS has 
determined that the mitigation measures required by the IHA provide the 
means of effecting the least practicable impact on marine mammal 
species or stocks and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance. NMFS 
provides responses to the mitigation measures suggested by NRDC et al., 
including survey design standards and review, use of an alternative 
multi-beam echosounder, sound source validation, alternate safety zone 
distances, real-time monitoring, and technology-based mitigation, in 
the following responses.
    Comment 20: NRDC et al. state that NMFS should require that the 
airgun survey vessel use the lowest practicable source level, minimize 
horizontal propagation of the sound signal, and minimize the density of 
tracklines consistent with the purposes of the survey. NRDC et al. 
state that while cursory consideration is given to the source level, 
little explanation of the conclusion that a 36-airgun array is required 
is offered. NRDC et al. would note that, in the past, the California 
Coastal Commission has required USGS to reduce the size of its array 
for seismic hazards work, and to use alternative seismic technologies 
to reduce acoustic intensities during earthquake hazard surveys to 
their lowest practicable level.
    Response: NMFS encourages all seismic surveys using airguns as a 
sound source to use the lowest practicable source level to achieve the 
purposes of the action. In order to fulfill the purpose of the seismic 
survey to establish the outer limits of the U.S. ECS, USGS must 
establish sediment thickness along the continental margin, which can be 
in excess of 8 to 10 km (4.3 to 5.4 nmi) in the Atlantic. The seismic 
survey therefore requires the use of large sources and low frequencies. 
For the planned seismic survey, the multi-channel streamer, augmented 
by widely spaced free-floating sonobuoys (acquiring data up to 30 km 
[16.2 nmi] from the ship) provides the ability to acquire oblique 
angles to better resolve sedimentary velocities and determine accurate 
sediment thicknesses. In considering survey design, the guidelines 
regarding Article 76 of the Law of the Sea Convention state ``the low 
frequencies allow good penetration. The oblique angles allow the 
detection and measurement of velocity gradient zones as well as the 
more abrupt changes, which show up well on reflection profiles.'' The 
acquisition of refraction information from widely spaced sonobuoys 
provides an independent check on sediment thickness and the 
identification of basement which reduces uncertainty in determining the 
outer limit points of the ECS. The guidelines also state ``the survey 
must be designed to prove the continuity of the sediments from each 
selected fixed point to the foot of the slope.'' The Langseth source 
size is appropriate for imaging sediment thickness where the sediments 
are thickest (near the foot of the slope) and also have the resolution 
to determine the base of the sediments to between five and ten percent 
error.
    Regarding the comment about minimizing horizontal propagation of 
the sound signal, the configuration of the airgun array, as four 
adjacent linear arrays, causes the signals to constructively interfere 
in the vertical direction and destructively interfere in horizontal 
direction. This is evident in the elliptical shape of the modeled 
received signals presented in the EA.
    Regarding the comment about minimizing the density tracks 
consistent with the purposes of the seismic survey, the tracks are 
designed to fulfill the requirements of Article 76 of the Law of the 
Sea Convention. Trackline spacing and coverage is specified in the 
treaty to be no more than 111.1 km (60 nmi) apart. However, the 111.1 
km maximum is impractical unless the points on the tracks are exactly 
orthogonal between tracks at 60 nmi spacing. Any deviation of points 
from orthogonal between adjacent tracks will result in a distance 
greater than 60 nmi between points, which will not satisfy the 
requirements of Article 76. Hence the tracks are generally planned to 
be 55.6 to 92.6 km (30 to 50 nmi) apart. The planned seismic survey is 
for two field seasons, the first (2014) as a reconnaissance in the area 
of interest and the second (2015) to finalize outer limit points after 
interpretation of the data from the first field program is completed. 
The guidelines also note that ``. . . it is evident that . . . minimum 
data coverage could miss some important details of the morphology of 
the outer limit of the continental margin, and the resulting 1% line 
could only be a rough approximation of the true geological limit. 
Coastal states that suspect that such an approximation will be to their 
disadvantage will benefit from executing more comprehensive and 
detailed surveys. In general, the data coverage should reflect the 
complexity of the outer margin.'' The Atlantic margin is inferred to 
have geological complexity in the form of fracture zones, where the 
sediments could be thicker than in the intra-fracture zone regions. 
These fracture zones are the result of juxtaposing oceanic crust of 
different ages across ridge offsets during the spreading process. The 
2014 part of the seismic survey (with lines parallel to the margin) is 
intended to identify the possible existence of fracture zones that are 
sub-perpendicular to the margin. If these fracture zones can be 
identified, the 2015 component of the seismic survey is to then collect 
seismic data along tracks that follow where the sediment is thickest 
and therefore the size of the U.S. ECS can be established.
    Comment 21: NRDC et al. states that NMFS should require use of an 
alternative multi-beam echosounder to the one presently proposed.
    Response: NMFS disagrees with NRDC et al.'s recommendation as we do 
not have the authority to require the IHA applicant or action proponent 
to choose a different multi-beam echosounder system for the planned 
seismic survey. The multi-beam echosounder system that is currently 
installed on the Langseth is capable of mapping the seafloor in deep 
water and the characteristics of the system are well suited for meeting 
the research goals at the action area. It would not be practicable for 
the L-DEO and NSF to install a different multi-beam echosounder for the 
planned seismic

[[Page 52135]]

survey. Also, the multi-beam planned to be used on this seismic survey 
is not operating in the same way as it was in Madagascar, the seismic 
survey is in deep water and will be far off the coast. NRDC et al. did 
not recommend a specific multi-beam echosounder to use as an 
alternative to the one currently installed on the vessel and planned to 
be operated during the seismic survey. The multi-beam echosounder that 
is currently installed on the Langseth was evaluated in the NSF/USGS 
PEIS and in USGS's EA, and has been used on over 25 research seismic 
surveys since 2008 without association to any marine mammal strandings.
    Regarding the 2002 stranding in the Gulf of California, the multi-
beam echosounder system was on a different vessel, the R/V Maurice 
Ewing (Ewing), and is no longer operated by L-DEO. Although NRDC et al. 
suggests that the multi-beam echosounder system or other acoustic 
sources on the Ewing may have been associated with the 2002 stranding 
of 2 beaked whales, as noted in Cox et al. (2006), ``whether or not 
this survey caused the beaked whales to strand has been a matter of 
debate because of the small number of animals involved and a lack of 
knowledge regarding the temporal and spatial correlation between the 
animals and the sound source.'' As noted by Yoder (2002), there was no 
scientific linkage to the event with the Ewing's activities and the 
acoustic sources being used. Furthermore, Hildebrand (2006) has noted 
that ``the settings for these stranding are strikingly consistent: An 
island or archipelago with deep water nearby, appropriate for beaked 
whale foraging habitat. The conditions for mass stranding may be 
optimized when the sound source transits a deep channel between two 
islands, such as in the Bahamas, and apparently in the Madeira 
incident.'' The activities planned for the seismic survey are in remote 
deep water, far from any land mass and islands, and do not relate at 
all to the environmental scenarios noted by Hildebrand (2006).
    Regarding the 2008 stranding event in Madagascar and the Final 
Report of the Independent Scientific Review Panel (ISRP) cited to by 
NRDC et al., see the response to comment 5. As described in more detail 
in the response to comment 14, the tracklines for the current seismic 
survey are planned to occur in deep water and will not be conducted in 
a manner that is likely to result in the ``herding of sensitive 
species'' into canyons and other similar areas. Given these conditions, 
NMFS does not anticipate mass strandings from use of the planned multi-
beam echosounder.
    Comment 22: NRDC et al. states that the proposed IHA does not 
adequately consider, or fails to consider at all, sound source 
validation. NRDC et al. states that NMFS should require USGS to 
validate the assumptions about propagation distances used to establish 
exclusion and buffer zones and calculate take (i.e., at minimum, the 
160 dB and 180 dB isopleths). Sound source validation has been required 
of Arctic operators for several years, as part of their IHA compliance 
requirements, and has proven useful for establishing more accurate, in 
situ measurements of exclusion zones and for acquiring information on 
noise propagation.
    Response: NMFS disagrees with NRDC et al.'s assessment that a sound 
source validation was not adequately considered or required. Regarding 
concerns about validating the assumptions about propagation distances 
used to establish buffer and exclusion zones and calculated take, 
measuring sound source isopleths requires specialized sensors that are 
either self-contained buoys (such as those used by Tolstoy et al., 
2009), at the seafloor (such as those used by Thode et al., 2010), or 
deployed from a second ship, such as those used by Mosher et al., 
2009). Experiments with these instruments are non-trivial experiments 
in deep water and generally take several days of ship time (or two 
vessels) in order to establish shooting patterns, appropriate gain 
settings, and deployment/recovery of the instruments. L-DEO has 
demonstrated that in deep water, the propagation paths are simple and 
that the sound propagation models are conservative, i.e., they 
overestimate the distances to the Level A and B harassment isopleths 
(as demonstrated in Figures 11, 12 and 16 in the NSF/USGS PEIS Appendix 
H). Consequently, using the model parameters is a precautionary 
approach that saves considerable time and expense in conducting the 
seismic survey.
    Sound source validation has been required in the Arctic for several 
years, these validation experiments are routinely done in the Arctic 
because the seismic work is undertaken on the continental shelf and 
inner shelf (i.e., in shallow water where acoustic propagation paths 
are affected by factors such as bathymetry and seafloor lithology that 
are not accounted for in the modeling). The IHA requirements in the 
Arctic are also different from those of the Atlantic because of bowhead 
whales' (Balaena mysticetus) use for subsistence in the Native 
Community. The IHA requirements for the instruments document the 
vocalizations of the bowhead whale before, during, and after the 
seismic surveys, to understand their impact on subsistence hunting, as 
well as to document the migrations of this species (see https://scripps.ucsd.edu/labs/athode/arctic-research/). These same 
considerations do not exist in the deep, offshore Atlantic study area.
    As described in the NSF/USGS PEIS and USGS EA, the Langseth sound 
source has been calibrated in deep water and it was proven that the L-
DEO model is robust and conservative for establishing buffer and 
exclusion zones for mitigation purposes and calculating take. Given 
that the planned seismic survey occurs entirely in deep water, further 
sound source validation is not warranted.
    Comment 23: NRDC et al. state that NMFS should reconsider the size 
(distance) of the safety zone. The proposed IHA proposes establishing a 
safety zone of 180 dB re 1 [micro]Pa (with a 500 m minimum around the 
airgun array). Gedamke et al. (2011) has put traditional means of 
estimating safety zones in doubt. NRDC et al. state that NMFS should 
consider establishing an exclusion zone for shut-downs for certain 
target species. Although time/area closures are a more effective means 
of reducing cumulative exposures of wildlife to disruptive and harmful 
sound, expanded exclusion zones have value minimizing disruptions, and 
potentially in reducing the risk of hearing loss and injury, outside 
the seasonal closure areas. Visual sighting of any individual North 
Atlantic right whale at any distance should trigger a shut-down; for 
other species, shut-downs should occur if aggregations are observed 
within the 160 dB isopleth around the sound source.
    Response: NMFS disagrees with NRDC et al.'s recommendation that 
NMFS should reconsider the size (distance) of the exclusion zone. NMFS 
notes that the statement that the proposed IHA proposes establishing a 
safety zone of 180 dB re 1 [micro]Pa (with a 500 m minimum around the 
airgun array) is incorrect. NRDC et al. may be referring to BOEM/BSEE 
Joint NTL No. 2012-G02 (available online at: https://www.boem.gov/Regulations/Notices-To-Lessees/2012/2012-JOINT-G02-pdf.aspx), which 
requires an immediate shut-down of the airgun operations ``within an 
estimated 500 m of the sound source array.'' The 180 dB exclusion zone 
for USGS's planned survey is 927 m for the 36-airgun array and 100 m 
for the single airgun. See the response to comment 31 for further 
information about the exclusion zone.

[[Page 52136]]

    NNMFS also notes that the required mitigation measures already 
require shut-downs and/or power-downs for species of special concern. 
Considering the rarity and conservation status for the North Atlantic 
right whale, the airguns will be shut-down immediately in the unlikely 
event that this species is observed, regardless of the distance from 
the Langseth. The airgun array shall not resume firing (with ramp-up) 
until 30 minutes after the last documented North Atlantic right whale 
visual sighting. Additionally, the mitigation measures state that 
concentrations of humpback, sei, fin, blue, and/or sperm whales will be 
avoided if possible (i.e., exposing concentrations of animals to 160 
dB), and the array will be powered-down if necessary. For purposes of 
this planned survey, a concentration or group of whales will consist of 
six or more individuals visually sighted that do not appear to be 
traveling (e.g., feeding, socializing, etc.).
    Comment 24: NRDC et al. state that real-time monitoring effort in 
the proposed IHA is inadequate. NRDC et al. states that supplemental 
methods that have been used on certain other projects include 
hydrophone buoys and other platforms for acoustic monitoring, aerial 
surveys, shore-based monitoring, and the use of additional small 
vessels.
    Response: NMFS has not included hydrophone buoys for acoustic 
monitoring, aerial surveys, shore-based monitoring, or the use of 
additional small/support vessels in the IHA as they are not considered 
practicable for USGS's seismic survey. Given that the seismic survey 
will be occurring in deep water and transiting long distances, it is 
not logistically practicable at this time to use moored platforms or 
moored hydrophones to assist in detecting the presence of marine 
mammals and potential impacts from the sound sources during the seismic 
survey. The planned seismic survey is generally taking place more than 
200 km (108 nmi) from the U.S. coastline. This large distance renders 
shore-based monitoring ineffective and precludes aerial surveys by 
small airplanes or helicopters because of range limitations and safety 
issues. Also, the Langseth does not have a landing pad that would allow 
for helicopter monitoring from the vessel. In certain situations, NMFS 
has recommended the use of additional support vessels to enhance PSO 
monitoring effort during seismic surveys. For this seismic survey, 
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 the exclusion zones. An additional vessel would 
unnecessarily increase noise and emissions in the action area as well. 
The use of an additional contract vessel to supplement visual and 
acoustic monitoring is not necessary and will not be practicable as it 
would need to be capable of operating for the entire duration of the 
seismic survey without returning to shore which would add 10 to 30% to 
the cost of the project. Finally, the Langseth has limited 
maneuverability during airgun operations and cannot deploy or recover 
small vessels for activities such as hydrophone acoustic monitoring.
    Comment 25: NRDC et al. states that the requirements with respect 
to PSOs are inconsistent with survey conventions and with prior studies 
of observer effectiveness. NRDC et al. state four hour work cycles are 
not appropriate and comment that NMFS offers no details about the 
training requirements of its vessel-based observers.
    Response: The general duties of PSOs required for seismic surveys 
is to visually observe the immediate environment for protected species 
whose detection (relative to a sound source) triggers the 
implementation of mitigation requirements, monitoring compliance with 
mitigation requirements, collecting data by defined protocols, 
preparing daily reports, and submitting reports to NMFS. During seismic 
operations, at least five PSOs (four Protected Species Visual Observers 
[PSVOs] and one Protected Species Acoustic Observer [PSAO]) will be 
based aboard the Langseth. USGS will appoint the PSOs with NMFS's 
concurrence. The PSOs aboard the Langseth are professional and 
experienced observers provided to USGS under contract to RPS and have 
been in place during seismic surveys since 2008. RPS's PSOs and PAM 
operators complete in-house training. PSO candidates must pass a 
protected species identification test and a mitigation and monitoring 
practices exam with a minimum grade of 80%. The RPS training program 
includes, but is not limited to: background on protected species laws 
in the U.S. and worldwide, an introduction to seismic surveys (purpose, 
types, and equipment), potential impacts of underwater sound on 
protected species, protected species in the Gulf of Mexico and other 
regions, visual monitoring methods, acoustic monitoring methods, 
protected species detection in the field, implementation of mitigation 
measures (exclusion and buffer zones, ramp-ups, power-downs, shut-
downs, delays, etc.), and data collection and report preparation. In 
November 2013, NMFS prepared and published, with input from BOEM and 
BSEE, a technical memorandum (tech memo) titled ``National Standards 
for a Protected Species Observer and Data Management Program: A Model 
Using Geological and Geophysical Surveys'' (Baker et al., 2013) that 
makes recommendations on establishing a training program, PSO 
eligibility and qualifications, as well as PSO evaluation during 
permit/authorization approval. The tech memo is available online at: 
https://www.nmfs.noaa.gov/pr/publications/techmemo/
observersnmfsopr49.pdf. NMFS's current practice is to deem PSO 
candidates as NMFS-approved or qualified on a case-by-case or project-
by-project basis after review of their resume and/or curriculum vitae. 
USGS's PSOs have the necessary education and/or experience requirements 
and their training generally follows the standard components 
recommended in NMFS's tech memo.
    Observations will take place during ongoing daytime operations and 
nighttime ramp-ups of the airguns. During the majority of seismic 
operations, two PSVOs will be on duty from the observation tower (i.e., 
the best available vantage point on the source vessel) to monitor 
marine mammals near the seismic vessel. Use of two simultaneous PSVOs 
will increase the effectiveness of detecting animals near the source 
vessel. However, during meal times and bathroom breaks, it is sometimes 
difficult to have two PSVOs on effort, but at least one PSVO will be on 
duty. Regarding the comment about four-hour work shifts, the IHA states 
that PSVO shifts shall not exceed four hours, allowing shifts to be 
shorter. PSOs will rotate through visual watch and the PAM station (see 
next response) with breaks in between to avoid fatigue and increase the 
detection of marine mammals present in the area.
    Comment 26: NRDC et al. states that NMFS only requires PAM as 
practicable with no further guidance on when monitoring is or isn't 
practicable. NRDC et al. state that it is unrealistic for one 
bioacoustician to monitor the PAM system 24 hours a day.
    Response: The NSF/USGS PEIS identifies PAM as an important tool to 
augment visual observations (section 2.4.2). As described in the USGS 
EA, PAM would be monitored continuously during seismic operations. 
During the survey, at least four PSVOs and one expert biacoustician 
(i.e., PSAO) will be based aboard the Langseth. The IHA requires that 
an expert biacoustician design and set up the PAM system, be

[[Page 52137]]

present to oversee the PAM, and available when technical issues occur 
during the survey. The PAM system will be monitored at all times, in 
shifts no longer than six hours, with the PSOs sharing the workload. 
Hence, PSOs will rotate through visual watch and the PAM station with 
breaks in between to avoid fatigue and increase the detection of marine 
mammals present in the area.
    Comment 27: NRDC et al. state that the proposed IHA makes no 
consideration of limiting activities in low-visibility conditions or at 
night.
    Response: NMFS disagrees with the commenters' assessment. The IHA 
does consider and address airgun operations during low-visibility and 
nighttime conditions. No initiation of airgun array operations is 
permitted from a shut-down position at night or during low-light hours 
(such as in dense fog or heavy rain) when the entire relevant exclusion 
zone cannot be effectively monitored by the PSVO(s) on duty. However, 
survey operations may continue into night and low-light hours if the 
segment(s) of the survey is initiated when the entire relevant 
exclusion zones are visible and can be effectively monitored. Limiting 
or suspending the seismic survey in low visibility conditions or at 
night would significantly extend the duration of the seismic survey.
    Comment 28: NRDC et al. states that NMFS should consider 
technology-based mitigation.
    Response: While NMFS encourages the development of new or 
alternative technologies to reduce potential impacts to marine mammals 
from underwater sound, NMFS did not include a requirement in the IHA to 
use or test the use of new technologies during the USGS seismic survey 
as none are currently available or proposed to be used by USGS. As 
discussed in the NSF/USGS PEIS (Section 2.6), alternative technologies 
to airguns were considered but eliminated from further analysis as 
those technologies were not commercially viable. USGS, NSF, and L-DEO 
continue to closely monitor the development and progress of these types 
of systems; however, at this point and time, these systems are still 
not commercially available. Geo-Kinetics, mentioned by NRDC as a 
potentially viable option for marine vibroseis does not have a viable 
towable array and its current testing is limited to transition zone 
settings. Other possible vibroseis developments lack even prototypes to 
test. Similarly, engineering enhancements to airguns to reduce high 
frequencies are currently being developed by industry, however, at 
present, these airguns are still not commercially available. L-DEO has 
maintained contact and is in communication with a number of developers 
and companies to express a willingness to serve as a test-bed for any 
such new technologies. As noted in the NSF/USGS PEIS, should new 
technologies to conduct marine seismic surveys become available, USGS 
and NSF would consider whether they would be effective tools to meet 
research goals (and assess any potential environmental impacts).
    Of the various technologies cited in the 2009 Okeanos workshop 
report, few if any have reached operational viability. While the marine 
vibrator technology has been long discussed and evaluated, the 
technology is still unrealized commercially. According to Pramik 
(2013), the leading development effort by the Joint Industry Programme 
``has the goal of developing three competing designs within the next 
few years.'' Geo-Kinetics has recently announced a commercial product 
called AquaVib, but that product produces relatively low-power, and is 
intended for use in very shallow water depths in sensitive environments 
and the vicinity of pipelines or other infrastructure. The instrument 
is entirely unsuited to deep-water, long-offset reflection profiling. 
The BP North America staggered burst technique would have to be 
developed well beyond the patent stage to be remotely practicable and 
would require extensive modification and testing of the Langseth sound 
source and recording systems. None of the other technologies considered 
(i.e., gravity, electromagnetic, Deep Towed Acoustics/Geophysics System 
developed by the U.S. Navy [DTAGS], etc.) can produce the resolution or 
sub-seafloor penetration required to resolve sediment thickness and 
geologic structure at the requisite scales. Improving the streamer 
signal to noise through improved telemetry (e.g., fiber optic cable) 
while desirable, would involve replacing the Langseth streamers and 
acquisition units, requiring a major capital expenditure.
    The multi-channel seismic reflection technique (augmented with 
refraction information) is the de facto standard for determining 
sediment thickness for the purposes of the Law of the Sea Convention. 
Sediment thickness cannot be determined by any other known methodology 
and cannot be deduced from modeling alone. Sediment thickness is one of 
two formulae that can be used to establish the outer limits of the ECS. 
The guidelines developed related to Article 76 state ``the Commission 
(on the Limits of the Continental Shelf) will regard the data provided 
by seismic reflection and seismic refraction surveys as the primary 
source of evidence for mapping and determining sediment thickness.'' 
Further, ``[t]he Commission will regard multi-channel seismic data as 
the most authoritative source of evidence for the determination of 
sediment thickness.''
    Some nations have resurveyed their ECS regions for sediment 
thickness with additional seismic reflection data because the initial 
data collection and delineation of the outer limits of the ECS were not 
considered adequate and convincing. These coastal States include Russia 
in the Arctic, Brazil off their southern coast, the joint submission of 
France, Ireland, Spain, and United Kingdom in the Bay of Biscay, and 
Indonesia in the area northwest of Sumatra. Hence, sufficient seismic 
reflection and refraction data to substantiate the outer limits is a 
requirement of the ECS Article 76 process. Acquiring sufficient data to 
delineate the continental shelf of the U.S. is part of the overall 
survey design off the Atlantic margin.

Monitoring and Reporting

    Comment 29: The Commission believes that NMFS misinterpreted its 
implementing regulations, which require that applicants include ``the 
suggested means of accomplishing the necessary monitoring and reporting 
that will result in increased knowledge of the species, the level of 
taking or impacts on populations of marine mammals that are expected to 
be present while conducting activities, and suggested means of 
minimizing burdens by coordinating such reporting requirements with 
other schemes already applicable to persons conducting such activity.'' 
The Commission believes that monitoring and reporting requirements need 
to be sufficient to provide accurate information on the numbers of 
marine mammals being taken and the manner in which they are taken, not 
merely better information on the qualitative nature of the impacts. The 
Commission continues to believe that appropriate g(0) and f(0) values 
are essential for making accurate estimates of the numbers of marine 
mammals taken during surveys. The Commission recommends that NMFS 
consult with the funding agency (e.g., USGS or NSF) and individual 
applicants (e.g., L-DEO, SIO, ASC and other related entities) to 
develop, validate, and implement a monitoring program that provides a 
scientifically sound, reasonably accurate assessment of the types of 
marine mammal takes and the actual numbers

[[Page 52138]]

of marine mammals taken, accounting for applicable g(0) and f(0) 
values.
    Response: NMFS does not believe that we misinterpreted the MMPA 
implementing regulations in our previous response that the Commission 
references. In the sentence quoted by the Commission, if we assume that 
the phrase ``increased knowledge of'' does not modify ``the level of 
taking,'' that the phrase it would read: ``The suggested means of 
accomplishing the necessary monitoring and reporting that will result 
in . . . the level of taking or impacts on populations,'' which does 
not make sense. However, even putting the unclear grammatical issue 
aside, NMFS does not believe that an appropriate interpretation of the 
regulations suggests that the monitoring of an authorized entity must 
be able to quantify the exact number of takes that occurred during the 
action, but rather that the monitoring increase understanding of the 
level and effects of the action. In fact, the Commission's comment 
supports this interpretation. As noted by the Commission, section 
101(a)(5)(D)(iv) requires that NMFS ``modify, suspend, or revoke an 
authorization'' if it finds, among other things, that the authorized 
taking is having more than a negligible impact or that more than small 
numbers of marine mammals are being taken. Both of these findings, 
negligible impact and small numbers, may be made using qualitative, or 
relative (to the stock abundance) information, and the sorts of 
qualitative, or more relative, information collected during the wide 
variety of monitoring that is conducted pursuant to MMPA authorizations 
can either be used to provide broad support for the findings underlying 
the issuance of an IHA or can highlight red flags that might 
necessitate either a reconsideration of an issued IHA or a change in 
analyses in future authorizations. NMFS's previous response is included 
below for reference.
    NMFS's implementing regulations require that applicants include 
monitoring that will result in ``an increased knowledge of the species, 
the level of taking or impacts on populations of marine mammals that 
are expected to be present while conducting activities . . .'' This 
increased knowledge of the level of taking could be qualitative or 
relative in nature, or it could be more directly quantitative. 
Scientists use g(0) and f(0) values in systematic marine mammal surveys 
to account for the undetected animals indicated above, however, these 
values are not simply established and the g(0) value varies across 
every observer based on their sighting acumen. While we want to be 
clear that NMFS do not generally believe that post-activity take 
estimates using f(0) and g(0) are required to meet the monitoring 
requirement of the MMPA, in the context of the NSF and L-DEO's 
monitoring plan, NMFS agree that developing and incorporating a way to 
better interpret the results of their monitoring (perhaps a simplified 
or generalized version of g(0) and f(0)) is a good idea. NMFS is 
continuing to examine this issue with USGS and NSF to develop ways to 
improve their post-survey take estimates. NMFS will consult with the 
Commission and NMFS scientists prior to finalizing these 
recommendations.
    NMFS note that current monitoring measures for past and current 
IHAs for research seismic surveys require the collection of visual 
observation data by PSOs prior to, during, and after airgun operations. 
This data collection may contribute to baseline data on marine mammals 
(presence/absence) and provide some generalized support for estimated 
take numbers (as well as providing data regarding behavioral responses 
to seismic operation that are observable at the surface). However, it 
is unlikely that the information gathered from these cruises along 
would result in any statistically robust conclusions for any particular 
species because of the small number of animals typically observed.

Acoustic Thresholds

    Comment 30: NRDC et al. and COA state that the current NMFS 160 dB 
threshold for Level B harassment does not reflect the best available 
science and is not sufficiently conservative. NRDC et al. state that 
NMFS's use of a single, non-conservative, bright-line threshold for all 
species is contrary to recent science and is untenable. NRDC et al. 
state that in particular, the 160 dB threshold is non-conservative, 
since the scientific literature establishes that behavioral disruption 
can occur at substantially lower received levels for some species. NRDC 
et al. state that NMFS should employ a combination of specific 
thresholds for which sufficient species-specific data are available and 
generalized thresholds for all other species.
    Response: NMFS's practice has been to apply the 160 dB received 
level threshold for underwater impulse sound levels to determine 
whether take by Level B harassment occurs. Specifically, NMFS derived 
the 160 dB threshold data from mother-calf pairs of migrating gray 
whales (Malme et al., 1983, 1984) and bowhead whales (Richardson et 
al., 1985, 1986) responding to airgun operations. NMFS acknowledge 
there is more recent information bearing on behavioral reactions to 
seismic airguns, but those data only illustrate how complex and 
context-dependent the relationship is between the two, and do not, as a 
whole, invalidate the current threshold. Accordingly, it is not a 
matter of merely replacing the existing threshold with a new one. NMFS 
discussed the science on this issue qualitatively in our analysis of 
potential effects to marine mammals in the Federal Register notice for 
the proposed IHA (79 FR 35642, June 23, 2014). NMFS is currently 
developing revised acoustic guidelines for assessing the effects of 
anthropogenic sound on marine mammals. Until NMFS finalizes these 
guidelines (a process that includes internal agency review, public 
notice and comment, and peer review), NMFS will continue to rely on the 
existing criteria for Level A and Level B harassment shown in Table 3 
of the notice for the proposed IHA (79 FR 35642, June 23, 2014).
    As mentioned in the Federal Register notice for the proposed IHA 
(79 FR 35642, June 23, 2014), NMFS expect that the onset for behavioral 
harassment is largely context dependent (e.g., behavioral state of the 
animals, distance from the sound source, etc.) when evaluating 
behavioral responses of marine mammals to acoustic sources. Although 
using a uniform sound pressure level of 160 dB for the onset of 
behavioral harassment for impulse noises may not capture all of the 
nuances of different marine mammal reactions to sound, it is an 
appropriate way to manage and regulate anthropogenic noise impacts on 
marine mammals until NMFS finalizes its acoustic guidelines.
    Comment 31: COA and NRDC et al. assert that our preliminary 
determinations for Level A take and the likelihood of temporary and or 
permanent threshold shift do not consider the best available science. 
COA cites Lucke et al. (2009); Thompson et al. (1998); Kastak et al. 
(2008); Kujawa and Lieberman (2009); Wood et al. (2012); and Cox et al. 
(2006). NRDC et al. also cite Lucke et al. (2009).
    Response: As explained in the notice of the proposed IHA (79 
FR35642, June 23, 2014), USGS will be required to establish a 180 and 
190 dB re 1 [mu]Pa exclusion zone for marine mammals before the two 
string airgun array or a single airgun array is in operation. NMFS 
expects that the required vessel-based visual monitoring of the 
exclusion zones is appropriate to implement mitigation measures to 
prevent Level A

[[Page 52139]]

harassment. First, if the PSOs observe marine mammals approaching the 
exclusion zone, USGS must shut-down or power-down seismic operations to 
ensure that the marine mammal does not approach the applicable 
exclusion radius. Second, if USGS detects a marine mammal outside the 
exclusion zone, and the animal, based on its position and the relative 
motion, is likely to enter the exclusion zone, USGS may alter the 
vessel's speed and/or course, when practical and safe, in combination 
with powering-down or shutting-down the airguns, to minimize the 
effects of the seismic survey. The avoidance behaviors discussed in the 
notice of the proposed IHA (79 FR35642, June 23, 2014) supports our 
expectations that individuals will avoid exposure at higher levels. 
Also, it is unlikely that animals would encounter repeated exposures at 
very close distances to the sound source because USGS would implement 
the required shut-down and power-down mitigation measures to ensure 
that marine mammals do not approach the applicable exclusion zones for 
Level A harassment.
    NMFS' current Level A thresholds, which identify levels above which 
PTS could be incurred, were designed to be precautionary in that they 
were based on levels were animals had incurred TTS. NMFS is currently 
working on finalizing Acoustic Guidance that will identify revised TTS 
and PTS thresholds that references the studies identified by COA and 
NRDC et al. In order to ensure the best possible product, the process 
for developing the revised thresholds includes both peer and public 
review (both of which have already occurred) and NMFS will begin 
applying the new thresholds once the peer and public input have been 
addressed and the Acoustic Guidance is finalized.
    Regarding the Lucke et al. (2009) study, the authors found a 
threshold shift (TS) of a harbor porpoise after exposing it to airgun 
noise (single pulse) with a received sound pressure level (SPL) at 
200.2 dB (peak-to-peak) re 1 [mu]Pa, which corresponds to a sound 
exposure level of 164.5 dB re 1 [mu]Pa\2\s after integrating exposure. 
NMFS currently uses the root-mean-square (rms) of received SPL at 180 
dB and 190 dB re 1 [mu]Pa as the threshold above which permanent 
threshold shift (PTS) could occur for cetaceans and pinnipeds, 
respectively. Because the airgun noise is a broadband impulse, one 
cannot directly extrapolate the equivalent of rms SPL from the reported 
peak-to-peak SPLs reported in Lucke et al. (2009). However, applying a 
conservative conversion factor of 16 dB for broadband signals from 
seismic surveys (Harris et al., 2001; McCauley et al., 2000) to correct 
for the difference between peak-to-peak levels reported in Lucke et al. 
(2009) and rms SPLs; the rms SPL for TTS would be approximately 184 dB 
re 1 [mu]Pa, and the received levels associated with PTS (Level A 
harassment) would be higher. This is still above the current 180 dB rms 
re 1 [mu]Pa threshold for injury. Yet, NMFS recognizes that the 
temporary threshold shift (TTS) of harbor porpoise is lower than other 
cetacean species empirically tested (Finneran et al., 2002; Finneran 
and Schlundt, 2010; Kastelein et al., 2012). NMFS considered this 
information in the notice of the proposed IHA (79 FR35642, June 23, 
2014).
    The Thompson et al. (1998) telemetry study on harbor (Phoca 
vitulina) and grey seals (Halichoerus grypus) suggested that avoidance 
and other behavioral reactions by individual seals to small airgun 
sources may at times be strong, but short-lived. The researchers 
conducted 1-hour controlled exposure experiments exposing individual 
seals fitted with telemetry devices to small airguns with a reported 
source level of 215-224 dB re 1 [mu]Pa (peak-to-peak) (Thompson et al., 
1998; Gordon et al., 2003). The researchers measured dive behavior, 
swim speed heart rate and stomach temperature (indicator for feeding), 
but they did not measure hearing threshold shift in the animals. The 
researchers observed startle responses, decreases in heart rate, and 
temporary cessation of feeding. In six out of eight trials, harbor 
seals exhibited strong avoidance behaviors, and swam rapidly away from 
the source (Thompson et al., 1998; Gordon et al., 2003). One seal 
showed no detectable response to the airguns, approaching within 300 m 
(984 ft) of the source (Gordon et al., 2003). However, they note that 
the behavioral responses were short-lived and the seals' behavior 
returned to normal after the trials (Thompson et al., 1998; Gordon et 
al., 2003). The study does not discuss temporary threshold shift or 
permanent threshold shift in harbor seals and the estimated rms SPL for 
this survey is approximately 200 dB re 1 [mu]Pa, well above NMFS's 
current 180 dB rms re: 1 [mu]Pa threshold for injury for cetaceans and 
NMFS' current 190 dB rms re 1 [mu]Pa threshold for injury for pinnipeds 
(accounting for the fact that the rms sound pressure level (in dB) is 
typically 16 dB less than the peak-to-peak level).
    In a study on the effect of non-impulsive sound sources on marine 
mammal hearing, Kastak et al. (2008) exposed one harbor seal to an 
underwater 4.1 kHz pure tone fatiguing stimulus with a maximum received 
sound pressure of 184 dB re 1 [mu]Pa for 60 seconds (Kastak et al., 
2008; Finneran and Branstetter, 2013). A second 60-second exposure 
resulted in an estimated threshold shift of greater than 50 dB at a 
test frequency of 5.8 kHz (Kastak et al., 2008). The seal recovered at 
a rate of -10 dB per log (min). However, 2 months post-exposure, the 
researchers observed incomplete recovery from the initial threshold 
shift resulting in an apparent permanent threshold shift of 7 to 10 dB 
in the seal (Kastak et al., 2008). NMFS notes that seismic sound is an 
impulsive source, and the context of the study is related to the effect 
of non-impulsive sounds on marine mammals.
    NMFS also considered two other Kastak et al. (1999, 2005) studies. 
Kastak et al. (1999) reported TTS of approximately 4-5 dB in three 
species of pinnipeds (harbor seal, California sea lion, and northern 
elephant seal) after underwater exposure for approximately 20 minutes 
to sound with frequencies ranging from 100 to 2,000 Hz at received 
levels 60 to 75 dB above hearing threshold. This approach allowed 
similar effective exposure conditions to each of the subjects, but 
resulted in variable absolute exposure values depending on subject and 
test frequency. Recovery to near baseline levels was reported within 24 
hours of sound exposure. Kastak et al. (2005) followed up on their 
previous work, exposing the same test subjects to higher levels of 
sound for longer durations. The animals were exposed to octave-band 
sound for up to 50 minutes of net exposure. The study reported that the 
harbor seal experienced TTS of 6 dB after a 25-minute exposure to 2.5 
kHz of octave-band sound at 152 dB (183 dB SEL). The California sea 
lion demonstrated onset of TTS after exposure to 174 dB (206 dB SEL).
    NMFS acknowledges that PTS could occur if an animal experiences 
repeated exposures to TTS levels. However, an animal would need to stay 
very close to the sound source for an extended amount of time to incur 
a serious degree of PTS, which in this case, it would be highly 
unlikely due to the required mitigation measures in place to avoid 
Level A harassment and the expectation that a mobile marine mammal 
would generally avoid an area where received sound pulse levels exceed 
160 dB re 1 [mu]Pa (rms) (review in Richardson et al., 1995; Southall 
et al., 2007).
    NMFS also considered recent studies by Kujawa and Liberman (2009) 
and Lin et al. (2011). These studies found that

[[Page 52140]]

despite completely reversible threshold shifts that leave cochlear 
sensory cells intact, large threshold shifts (40 to 50 dB) could cause 
synaptic level changes and delayed cochlear nerve degeneration in mice 
and guinea pigs, respectively. NMFS notes that the high level of TTS 
that led to the synaptic changes shown in these studies is in the range 
of the high degree of TTS that Southall et al. (2007) used to calculate 
PTS levels. It is not known whether smaller levels of TTS would lead to 
similar changes. NMFS, however, acknowledges the complexity of noise 
exposure on the nervous system, and will re-examine this issue as more 
data become available.
    In contrast, a recent study on bottlenose dolphins (Schlundt, et 
al., 2013) measured hearing thresholds at multiple frequencies to 
determine the amount of TTS induced before and after exposure to a 
sequence of impulses produced by a seismic airgun. The airgun volume 
and operating pressure varied from 40 to 150 in\3\ and 1,000 to 2,000 
psi, respectively. After three years and 180 sessions, the authors 
observed no significant TTS at any test frequency, for any combinations 
of airgun volume, pressure, or proximity to the dolphin during 
behavioral tests (Schlundt, et al., 2013). Schlundt et al. (2013) 
suggest that the potential for airguns to cause hearing loss in 
dolphins is lower than previously predicted, perhaps as a result of the 
low-frequency content of airgun impulses compared to the high-frequency 
hearing ability of dolphins.
    Comment 32: COA requested that NMFS use a behavioral threshold 
below 160 dB for estimating take based on results reported in Clark and 
Gagnon (2006), MacLeod et al. (2006), Risch et al. (2012), McCauley et 
al. (1998), McDonald et al. (1995), Bain and Williams (2006), DeRuiter 
et al. (2013). They also cite comments submitted by Clark et al. (2012) 
on the Arctic Ocean Draft Environmental Impact Statement regarding 
NMFS's current acoustic thresholds.
    Response: NMFS is constantly evaluating new science and how to best 
incorporate it into our decisions. This process involves careful 
consideration of new data and how it is best interpreted within the 
context of a given management framework. Each of these articles 
emphasizes the importance of context (e.g., behavioral state of the 
animals, distance from the sound source, etc.) in evaluating behavioral 
responses of marine mammals to acoustic sources.
    These papers and the studies discussed in the notice of the 
proposed IHA (79 FR 35642, June 23, 2014) note that there is 
variability in the behavioral responses of marine mammals to noise 
exposure. However, it is important to consider the context in 
predicting and observing the level and type of behavioral response to 
anthropogenic signals (Ellison et al., 2012). There are many studies 
showing that marine mammals do not show behavioral responses when 
exposed to multiple pulses at received levels at or above 160 dB re 1 
[mu]Pa (e.g., Malme et al., 1983; Malme et al., 1984; Richardson et 
al., 1986; Akamatsu et al., 1993; Madsen and Mohl, 2000; Harris et al., 
2001; Miller et al., 2005; and Weir, 2008). And other studies show that 
whales continue important behaviors in the presence of seismic pulses 
(e.g., Richardson et al., 1986; McDonald et al., 1995; Greene et al., 
1999a, 1999b; Nieukirk et al., 2004; Smultea et al., 2004; Holst et 
al., 2005, 2006; Dunn and Hernandez, 2009).
    In a passive acoustic research program that mapped the soundscape 
in the North Atlantic Clark and Gagnon (2006) reported that some fin 
whales (Balaenoptera physalus) stopped singing for an extended period 
starting soon after the onset of a seismic survey in the area. The 
study did not provide information on received levels or distance from 
the sound source. The authors could not determine whether or not the 
whales left the area ensonified by the survey, but the evidence 
suggests that most if not all singers remained in the area (Clark and 
Gagnon, 2006). Support for this statement comes from the fact that when 
the survey stopped temporarily, the whales resumed singing within a few 
hours and the number of singers increased with time (Clark and Gagnon, 
2006). Also, they observed that one whale continued to sing while the 
seismic survey was actively operating (Figure 4; Clark and Gagnon, 
2006).
    The authors conclude that there is not enough scientific knowledge 
to adequately evaluate whether or not these effects on singing or 
mating behaviors are significant or would alter survivorship or 
reproductive success (Clark and Gagnon, 2006). Thus, to address COA's 
concerns related to the results of this study, it is important to note 
that USGS's study area is well away from any known breeding/calving 
grounds for low frequency cetaceans, thereby reducing further the 
likelihood of causing an effect on marine mammals.
    MacLeod et al. (2006) discussed the possible displacement of fin 
and sei whales related to distribution patterns of the species during a 
large-scale seismic survey offshore the west coast of Scotland in 1998. 
The authors hypothesized about the relationship between the whale's 
absence and the concurrent seismic activity, but could not rule out 
other contributing factors (Macleod et al., 2006; Parsons et al., 
2009). NMFS would expect that marine mammals may briefly respond to 
underwater sound produced by the seismic survey by slightly changing 
their behavior or relocating a short distance. Based on the best 
available information, NMFS expects short-term disturbance reactions 
that are confined to relatively small distances and durations (Thompson 
et al., 1998; Thompson et al., 2013), with no long-term effects on 
recruitment or survival.
    Regarding the suggestion that blue whales ``noticeably'' changed 
course during the conduct of a seismic survey offshore Oregon, NMFS 
disagrees. NMFS considered the McDonald et al. (1995) paper in the 
notice for the proposed IHA (79 FR 35642, June 23, 2014). In brief, the 
study tracked three blue whales relative to a seismic survey with a 
1,600 in\3\ airgun array (smaller than the 6,600 in\3\ airgun array 
USGS will be using). The whale started its call sequence within 15 km 
(8.1 nmi) from the source, then followed a pursuit track that decreased 
its distance to the vessel where it stopped calling at a range of 10 km 
(5.4 nmi) (estimated received level at 143 dB re 1 [mu]Pa (peak-to-
peak) (McDonald et al., 1995). After that point, the ship increased its 
distance from the whale which continued a new call sequence after 
approximately one hour (McDonald et al., 1995) and 10 km from the ship. 
The authors suggested that the whale had taken a track paralleling the 
ship during the cessation phase but observed the whale moving 
diagonally away from the ship after approximately 30 minutes continuing 
to vocalize (McDonald et al., 1995). The authors also suggest that the 
whale may have approached the ship intentionally or perhaps was 
unaffected by the airguns. They concluded that there was insufficient 
data to infer conclusions from their study related to blue whale 
responses (McDonald et al., 1995).
    Risch et al. (2012) documented reductions in humpback whale 
(Megaptera novaeangliae) vocalizations in the Stellwagen Bank National 
Marine Sanctuary concurrent with transmissions of the Ocean Acoustic 
Waveguide Remote Sensing (OAWRS) low-frequency fish sensor system at 
distances of 200 km (108 nmi) from the source. The recorded OAWRS 
produced series of frequency modulated pulses and the signal received 
levels ranged from 88 to 110 dB re 1 [mu]Pa (Risch et al., 2012). The 
authors hypothesize that individuals did not leave the area but

[[Page 52141]]

instead ceased singing and noted that the duration and frequency range 
of the OAWRS signals (a novel sound to the whales) were similar to 
those of natural humpback whale song components used during mating 
(Risch et al., 2012). Thus, the novelty of the sound to humpback whales 
in the study area provided a compelling contextual probability for the 
observed effects (Risch et al., 2012). However, the authors did not 
state or imply that these changes had long-term effects on individual 
animals or populations (Risch et al., 2012), nor did they necessarily 
rise to the level of an MMPA take. Thus, to address COA's concerns 
related to the results of this study, NMFS again notes that the USGS's 
study area is well away from any known breeding/calving grounds for low 
frequency cetaceans, thereby reducing further the likelihood of causing 
an effect on marine mammals.
    NMFS considered the McCauley et al. (1998) paper (along with 
McCauley et al., 2000) in the notice of the proposed IHA (79 FR 35642, 
June 23, 2014). Briefly, McCauley et al. (1998, 2000) studied the 
responses of migrating humpback whales off western Australia to a full-
scale seismic survey with a 16-airgun array (2,678 in\3\) and to 
playbacks using a single, 20-in\3\ airgun. Both studies point to a 
contextual variability in the behavioral responses of marine mammals to 
sound exposure. The mean received level for initial avoidance of an 
approaching airgun was 140 dB re 1 [mu]Pa for resting humpback whale 
pods containing females. In contrast, some individual humpback whales, 
mainly males, approached within distances of 100 to 400 m (328 to 1,312 
ft), where sound levels were 179 dB re 1 [mu]Pa (McCauley et al., 
2000). The authors hypothesized that the males gravitated towards the 
single operating airgun possibly due to its similarity to the sound 
produced by humpback whales breaching (McCauley et al., 2000). Despite 
the evidence that some humpback whales exhibited localized avoidance 
reactions at received levels below 160 dB re 1 [mu]Pa, the authors 
found no evidence of any gross changes in migration routes, such as 
inshore/offshore displacement during seismic operations (McCauley et 
al., 1998, 2000).
    With repeated exposure to sound, many marine mammals may habituate 
to the sound at least partially (Richardson & Wursig, 1997). Bain and 
Williams (2006) examined the effects of a large airgun array (maximum 
total discharge volume of 1,100 in\3\) on six species in shallow waters 
off British Columbia and Washington: Harbor seal, California sea lion 
(Zalophus californianus), Steller sea lion (Eumetopias jubatus), gray 
whale (Eschrichtius robustus), Dall's porpoise (Phocoenoides dalli), 
and the harbor porpoise. Harbor porpoises showed ``apparent avoidance 
response'' at received levels less than 145 dB re 1 [mu]Pa at a 
distance of greater than 70 km (37.8 nmi) from the seismic source (Bain 
and Williams, 2006). However, the tendency for greater responsiveness 
by harbor porpoise is consistent with their relative responsiveness to 
boat traffic and some other acoustic sources (Richardson et al. 1995; 
Southall et al., 2007). In contrast, the authors reported that gray 
whales seemed to tolerate exposures to sound up to approximately 170 dB 
re 1 [mu]Pa (Bain and Williams, 2006) and Dall's porpoises occupied and 
tolerated areas receiving exposures of 170 to 180 dB re 1 [mu]Pa (Bain 
and Williams, 2006; Parsons et al., 2009). The authors observed several 
gray whales that moved away from the airguns toward deeper water where 
sound levels were higher due to propagation effects resulting in higher 
noise exposures (Bain and Williams, 2006). However, it is unclear 
whether their movements reflected a response to the sounds (Bain and 
Williams, 2006). Thus, the authors surmised that the gray whale data 
(i.e., voluntarily moving to areas where they are exposed to higher 
sound levels) are ambiguous at best because one expects the species to 
be the most sensitive to the low-frequency sound emanating from the 
airguns (Bain and Williams, 2006).
    DeRuiter et al. (2013) recently observed that beaked whales 
(considered a particularly sensitive species to sound) exposed to 
playbacks (i.e., simulated) of U.S. tactical mid-frequency sonar from 
89 to 127 dB re 1 [mu]Pa at close distances responded notably by 
altering their dive patterns. In contrast, individuals showed no 
behavioral responses when exposed to similar received levels from 
actual U.S. tactical mid-frequency sonar operated at much further 
distances (DeRuiter et al., 2013). As noted earlier, one must consider 
the importance of context (for example, the distance of a sound source 
from the animal) in predicting behavioral responses. Regarding the 
public comments submitted by Clark et al. (2012) in reference to NMFS's 
use of the current acoustic exposure criteria; please refer to our 
earlier response to COA.
    None of these studies on the effects of airgun noise on marine 
mammals point to any associated mortalities, strandings, or permanent 
abandonment of habitat by marine mammals. Bain and Williams (2006) 
specifically conclude that ``. . . although behavioral changes were 
observed, the precautions utilized in the SHIPS survey did not result 
in any detectable marine mammal mortalities during the survey, nor were 
any reported subsequently by the regional marine mammal stranding 
network . . .'' McCauley et al. (2000) concluded that any risk factors 
associated with their seismic survey for migrating individuals ``. . . 
lasted for a comparatively short period and resulted in only small 
range displacement . . .'' Further, the total discharge volume of the 
airgun arrays cited in McCauley et al., 1998, 2000; Bain and Williams, 
2006 were generally smaller or slightly larger than the 6,600 in\3\ 
array configurations planned for use during this survey (e.g., 2,768 
in\3\, McCauley et al., 1998; 6,730 in\3\, Bain and Williams, 2006). 
Thus, the USGS's 160-dB threshold radius may not reach the threshold 
distances reported in these studies.
    Currently NMFS is in the process of revising its behavioral noise 
exposure criteria based on the best and most recent scientific 
information. NMFS will use these criteria to develop methodologies to 
predict behavioral responses of marine mammals exposed to sound 
associated with seismic surveys (primary source is airguns). Although 
using a uniform sound pressure level of 160-dB re 1 [mu]Pa for the 
onset of behavioral harassment for impulse noises may not capture all 
of the nuances of different marine mammal reactions to sound, it is an 
appropriate way to manage and regulate anthropogenic noise impacts on 
marine mammals until NMFS finalizes its acoustic guidelines.
    Comment 33: NRDC et al. states that the use of a multi-pulse 
standard for behavior harassment is non-conservative, since it does not 
take into account the spreading of seismic pulses over time beyond a 
certain distance from the airgun array. NMFS's Open Water Panel for the 
Arctic, has twice characterized the airgun array as a mixed impulsive/
continuous noise source and has stated that NMFS should evaluate its 
impacts on that basis. NMFS should not ignore the science and analysis 
in a number of papers showing that seismic exploration in the Arctic, 
the east Atlantic, off Greenland, and off Australia has raised ambient 
noise levels at significant distances from the airgun array.
    Response: Propagation is complex and the physical property of 
sounds change as they travel through the environment making if often 
difficult to predict exactly when an impulsive source becomes more 
continuous (i.e., loses physical properties associated with impulsive 
sounds, such as fast rise and

[[Page 52142]]

high peak pressure). This is reason for classifying the behavioral 
thresholds based on characteristics at the source. However, it should 
be remembered that the 160 dB (rms) threshold for impulsive sounds was 
derived from data for mother-calf pairs of migrating gray whales (Malme 
et al. 1983, 1984) and bowhead whales (Richardson et al., 1985; 
Richardson et al., 1986) responding when specifically exposed to 
seismic airguns at distances farther from the source. Thus, the use of 
this threshold for behavioral response of marine mammals to seismic 
sources is appropriate (i.e., opposed to the 120 dB threshold which was 
based on responses to drilling and dredging activities). Furthermore, 
investigation of updated data since the derivation of the 160 dB 
threshold, indicates for the majority of behavioral responses 
associated with received levels below 160 dB are at distances fairly 
close to the source (less than 5 km) and have involved controlled 
playbacks to sources, which emphasizes that in addition to received 
level, other factors, like distance from the source or context of 
exposure are important considerations.
    Comment 34: NRDC et al. states that NMFS must consider that even 
behavioral disturbance can amount to Level A take if it interferes with 
essential life functions through secondary effects (e.g., displacement 
from migration paths, risks of ship strike or predation). NRDC et al. 
state that NMFS must take into account the best available science and 
set lower thresholds for take by Level A harassment, which would lead 
to larger exclusion zones around the seismic survey.
    Response: NMFS notes that Level B take has been defined previously 
in this document and specifically relates to behavioral disturbance, 
not the secondary effects the commenter notes. However, these secondary 
effects are very important and are considered in both the negligible 
impact analysis as well as qualitatively in the development of 
mitigation measures, via consideration of biologically important areas 
in the analysis and for time-area closures, or other important factors. 
Please see the response to comment 31 for a discussion of studies 
addressing PTS (Level A harassment).
    Comment 35: NRDC et al. state that behavioral take thresholds for 
the impulsive component airgun noise should be based on peak pressure 
rather than on rms, or dual criteria based on both peak pressure and 
rms should be used. NRDC et al. state that alternatively, NMFS should 
use the most biologically conservative method for calculating rms, 
following Madsen (2005).
    Response: NMFS disagrees that peak pressure is the appropriate 
metric associated with behavioral take. Peak pressure is more 
appropriate for injury associated with exposure at close distances to 
the source, not at distances where behavioral take is expected to occur 
(Southall et al., 2007). Finally, NMFS does rely on Madsen (2005) for 
calculating rms sound pressure (i.e., duration window associated with 
90% energy).
    Comment 36: NRDC et al. states that NMFS has failed to analyze 
masking effects or set thresholds for masking.
    Response: Exposure to seismic sources has been shown to have 
impacts on marine mammal vocalizations with sometimes animals 
vocalizing more (e.g., Di Iorio and Clark, 2009) in the presence of 
these sources and sometimes less (e.g., Blackwell et al., 2013). 
Additionally, many species have short-term and long-term means of 
dealing with masking. However, the energetic consequences of these 
adaptations are unknown. Recent published models have allowed the 
ability to better quantify the effects of masking on baleen whales for 
certain underwater sound sources, like shipping (e.g., change in 
communication space; Clark et al., 2009; Hatch et al., 2012). However, 
models for other sources have not been published. NMFS's notice of the 
proposed IHA (79 FR 35642, June 23, 2014) described the potential 
effects of the seismic survey on marine mammals, including masking. In 
general, NMFS expects the masking effects of airgun pulses to be minor, 
given the normally intermittent nature of the pulses and the fact that 
the acoustic footprint of the survey is only expected to overlay a low 
number of low-frequency hearing specialists and is not in any 
specifically identified biologically important areas.

NEPA Concerns

    Comment 37: NRDC et al. submitted comments on the first stated 
purpose of the study, which is to identify the outer limits of the U.S. 
continental shelf, also referred to as the ECS as defined by Article 76 
of the Convention of the Law of the Sea. NRDC et al. comment that the 
first stated purpose is concerning because of its implications for 
expanded oil and gas exploration in the region. NRDC et al. state that 
any consideration of this study, and in particular the cumulative 
impact of the assessment, must include consideration of the fact that 
this study's underlying purpose may be to increase the area of the Mid-
Atlantic that is open to oil and gas exploration and drilling and, 
therefore, must include an analysis of longer-term related effects on 
marine species and habitat of the various sources of increased 
disruption and harm caused by an influx of oil and gas exploration and 
drilling in the region.
    Response: NMFS has fully considered the purposes of the seismic 
survey, the first of which is to identify the outer limits of the U.S. 
ECS. NMFS disagrees with the commenter's assessment of the underlying 
purpose of the study may be to increase the area of the Mid-Atlantic 
that is open to oil and gas exploration and drilling. The planned 
seismic survey is independent of oil and gas exploration, which is 
regulated by the Bureau of Ocean Energy Management. The EA prepared by 
USGS, which NMFS has adopted, provided detailed information about the 
first purpose of the study.
    As explained in the previous notice for the proposed IHA (79 FR 
35642, June 23, 2014), one purpose of the planned study is to define 
the seafloor and sub-seafloor that is part of the U.S. ECS. Only after 
the ECS is delineated can it be designated for conservation, 
management, resource exploitation, or other purposes. The planned 
project is part of an Interagency Task Force that has been in existence 
since 2007 to identify all the parts of the U.S. margins beyond 200 nmi 
where the U.S. can potentially exert its sovereign rights, whether that 
be for conservation, management, exploitation, or other purposes. 
Unless the ECS is delineated as part of the U.S., it could potentially 
be developed and utilized outside of the U.S. regulatory framework. The 
ultimate determination as to whether the outer limits of the ECS will 
be delineated as part of the continental shelf of the U.S. is partially 
dependent upon the data that would be collected on this seismic survey. 
The ECS program has investigated potential ECS in the Arctic, Atlantic, 
Gulf of Mexico, Bering Sea, Pacific West Coast, Gulf of Alaska, Central 
Pacific Line Islands, and Western Pacific (Marianas). Only the Arctic, 
Atlantic, Gulf of Mexico, and Bering Sea are likely to use the sediment 
thickness formula for defining the outer limits of the ECS.
    The Atlantic margin is a priority for the U.S. ECS project. The 
Atlantic is probably the second largest region of ECS for the U.S. 
(second to the Arctic). The USGS participated in four field seasons of 
joint seismic-bathymetric work in the Arctic collaborative with the 
Geological Survey of Canada as the first priority between 2008 and 
2011. An opportunity to collect data for the ECS

[[Page 52143]]

in the Pacific Ocean was possible in 2011, and at that time, data were 
collected in the Gulf of Alaska and the Bering Sea, two areas of 
potential U.S. ECS. Since 2011, the Atlantic has been the highest 
priority for gathering ECS-relevant seismic data, both for the ECS 
Interagency Task Force and the Coastal and Marine Geology Program of 
USGS.
    The ECS project has teams that have been working in each region of 
the ECS for the U.S. since 2010. A preliminary assessment of existing 
data for the Atlantic margin was completed in 2012. Since that time, 
the final track line program has been proposed and modified per 
presentations to the ECS working group and the ECS seismic methodology 
team. This fiscal year (2014) is the first opportunity that both a ship 
and sufficient funding resources have been available for a field 
program in the Atlantic. Finishing data collection in 2015, would allow 
the Department of State sufficient time to complete the documentation 
of the outer limits of the ECS by the 2018 to 2019 deadline established 
in its 5-year program.
    The planned activity is not related to oil and gas exploration and 
will not expand the area of the Mid-Atlantic that is open to oil and 
gas exploration and drilling. The BOEM Planning Areas examined in their 
final PEIS already extend to 350 nmi beyond the baselines of the U.S. 
(https://www.boem.gov/Special-Information-Notice-February-2014/). The 
tracklines for the USGS study do not extend beyond 350 nmi, which is 
the furthest outer limit distance that could be used to delineate the 
ECS. Hence the BOEM PEIS already includes any area would be potential 
ECS in the analysis, including in the cumulative effects analysis. It 
is therefore incorrect to assert that this seismic survey will expand 
the area of the Mid-Atlantic that is open to oil and gas exploration, 
and such, would be inappropriate to include any analysis to this effect 
in the cumulative effects assessment of the planned action.
    Comment 38: NRDC et al. submitted comments on the second stated 
purpose of the study, which is to study the mass transport of sediments 
down the continental shelf as submarine landslides that may pose 
tsunamigenic (i.e., tsunami-related) hazards. NRDC et al. comment that 
there is little to substantiate the immediate need of the second stated 
purpose of the study. NRDC et al. comment that the draft EA offers no 
analysis of the ability to obtain information about sediment thickness 
and geologic structure by modeling or alternate means, no discussion of 
related survey data that may be available for extrapolation, nor any 
prediction of the actual risk to the Eastern Seaboard of a tsunami-
related submarine landslide.
    Response: NMFS first clarifies that the investigation of sediment 
thickness is related to the first purpose of the study, which is to 
establish the outer limits of the U.S. ECS. One of the criteria for 
defining the outer limits of the ECS under Article 76 involves 
measuring the thickness of the sediments beneath the seafloor but above 
the oceanic crust. The sediment thickness must be measured continuously 
from the foot of the continental slope seaward to a point where the 
outer limit point is identified. The established method for measuring 
sediment thickness is seismic reflection profiling (Kasuga et al., 
2000). Other scientific methods (such as measurements of marine gravity 
and magnetic anomalies) may be used to augment the geologic 
interpretation, but the internationally accepted method for measuring 
sediment thickness is seismic reflection profiling. An extensive review 
of the existing database (Hutchinson and other, 2004) demonstrated that 
existing seismic-reflection data are entirely insufficient to meet the 
line-spacing or velocity control requirements specified in Article 76. 
As part of the study, USGS plans to identify the locations of fracture 
zones, where the sediments could be thicker than in the intra-fracture 
zone regions. These fracture zones are the result of juxtaposing 
oceanic crust of different ages across ridge offsets during the 
spreading process. The 2014 part of the program (with lines parallel to 
the margin) is intended to identify the possible existence of fracture 
zones that are sub-perpendicular to the margin. If these fracture zones 
can be identified, the 2015 component of the seismic program is to then 
collect seismic data along tracks that follow where the sediment is 
thickest and therefore the size of the U.S. ECS can be established.
    NMFS has fully considered the second purpose of the study, which is 
to study the sudden mass transport of sediments down the continental 
shelf as submarine landslides that may pose tsunamigenic (i.e., 
tsunami-related) hazards. The EA prepared by USGS, which NMFS adopted, 
provides detailed information about the second purpose of the study, 
including information about its immediate need, the availability and 
limitations of other data, and the risk to the Eastern Seaboard of a 
tsunami-related submarine landslide.
    Since the 2004 Banda Aceh tsunami and the more recent 2010 Tohoku 
tsunami, the U.S. Nuclear Regulatory Agency has contracted with the 
USGS to evaluate tsunami hazards along the U.S. margins, because of the 
potential threat to, for example, nuclear power plants, coastal cities, 
industrial centers, and port facilities, including along the Atlantic. 
Other agencies such as FEMA offices in several coastal states and the 
City of Boston, Office of Emergency Management requested input and 
assessment from the USGS for their tsunami preparedness. Tsunamis on 
passive margins such as the Atlantic pose a challenge to regulators 
because these events are rare (i.e., low probability) but potentially 
devastating (i.e., high risk). The 1929 Grand Banks tsunami (Fine et 
al., 2005), measured and modeled overpressures on the New Jersey margin 
that can cause slope failure (Dugan et al., 2000), and evidence of 
enormous submarine landslides (such as the Cape Fear slide [Hornbach et 
al., 2007]) demonstrate that the Atlantic margin is not immune to the 
potential tsunamigenic hazard. As part of its research into submarine 
landslides, the USGS has utilized a multi-pronged approach, for 
example, analytic and numerical models (Geist and Parsons, 2006; Geist 
et al., 2009), geomorphologic analysis (Chaytor et al., 2007; Twichell 
et al., 2009; Locat et al., 2010), regional assessments using existing 
data (ten Brink et al., 2009; ten Brink et al., 2014), geotechnical 
analysis (on-going), and laboratory studies (on-going). No single 
landslide, however, has been mapped from its origin (headwall on the 
continental slope) to its runout on the lower rise/abyssal plain, with 
supporting evidence to show the aggradational and structural 
relationships in the subsurface among the different parts of the 
composite landslide system. This lack of information prevents further 
modeling of the processes of these landslides and evaluating the 
potential tsunamigenic risks they have posed or could pose along the 
Atlantic margin. The proposed cruise offers the opportunity to study 
the vertical (depth) aspects of two major landslides on the U.S. 
margin, and therefore leverage federal resources across two scientific 
programs and projects (ECS and Natural Hazards). USGS is attempting to 
eliminate redundant seismic surveys by combing field work for two 
projects (ECS and Natural Hazards).
    Comment 39: COA states that NMFS should prepare an Environmental 
Impact Statement (EIS), not an EA, to adequately consider the 
potentially significant impacts of the proposed action and full range 
of alternatives to the proposed action. COA also states that given that 
USGS's EA tiers to the NSF/USGS PEIS that was finalized in

[[Page 52144]]

2011, an updated EIS would provide information necessary to making an 
informed decision about the issuance of the IHA.
    Response: In accordance with the National Environmental Policy Act 
(NEPA; 42 U.S.C. 4321 et seq.), USGS completed an EA titled, 
``Environmental Assessment for Seismic Reflection Scientific Research 
Surveys during 2014 and 2015 in Support of Mapping the U.S. Atlantic 
Seaboard Extended Continental Margin and Investigating Tsunami 
Hazards.'' The EA was prepared by RPS Evan-Hamilton, Inc., in 
association with YOLO Environmental, Inc., GeoSpatial Strategy Group, 
and Ecology and Environment, Inc. on behalf of USGS. The EA analyzes 
the impacts on the human environment of conducting a seismic survey in 
the northwest Atlantic Ocean off the U.S. Eastern Seaboard (i.e., the 
action for which USGS applied to NMFS for an IHA). It includes an 
evaluation of three alternatives:
    (1) The proposed seismic survey and issuance of an associated IHA,
    (2) a no action alternative (i.e., do not issue an IHA and do not 
conduct the seismic survey), and
    (3) a corresponding seismic survey at an alternative time, along 
with issuance of an associated IHA.
    The EA tiers to the NSF and USGS's 2011 ``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). The EA 
also incorporates by reference the following documents per 40 CFR 
1502.21 and NOAA Administrative Order (NAO) 216-6 Sec.  5.09(d): The 
NSF's ``Environmental Analysis of a Marine Geophysical Survey by the R/
V Marcus G. Langseth in the Northeast Atlantic Ocean, June-July 2013; 
the NSF's ``Draft Environmental Assessment of a Marine Geophysical 
Survey by the R/V Marcus G. Langseth in the Atlantic Ocean off Cape 
Hatteras, September-October 2014''; and the Bureau of Ocean Energy 
Management's 2014 ``Programmatic Environmental Impact Statement 
Atlantic Outer Continental Shelf (OCS) Proposed Geological and 
Geophysical Activities Mid-Atlantic and South Atlantic Planning 
Areas.''
    NMFS independently reviewed USGS's EA, and concluded that the 
impacts evaluated by USGS are substantially the same as the impacts of 
the alternatives considered in issuing an IHA under the MMPA for USGS's 
marine seismic survey in the northwest Atlantic Ocean off the U.S. 
Eastern Seaboard during August to September 2014 and April to August 
2015. In addition, NMFS evaluated USGS's EA and found that it includes 
all required components for adoption by NOAA, including sufficient 
evidence and analysis for determining whether to prepare an EIS or a 
Finding of No Significant Impact (FONSI), a brief discussion of need 
for the proposed action, a listing of the alternatives to the proposed 
action, a description of the affected environment, and a brief 
discussion of the environmental impacts of the proposed action and 
alternatives. Regarding the comment that the USGS EA tiers to the NSF/
USGS PEIS that was finalized in 2011, NMFS notes that the USGS EA and 
the two NSF EAs incorporated by reference in the USGS EA incorporate 
site-specific and updated scientific information. As a result of this 
review, NMFS determined that it was not necessary to prepare a separate 
EA, Supplemental EA, or EIS to issue an IHA for USGS's proposed marine 
seismic survey, and adopted USGS's EA.
    NOAA Administrative Order (NAO) 216-6 contains criteria for 
determining the significance of the impacts of a proposed action. In 
addition, the Council on Environmental Quality (CEQ) regulations at 40 
CFR Sec.  1508.27 state that the significance of an action should be 
analyzed both in terms of ``context'' and ``intensity.'' NMFS evaluated 
the significance of this action based on the NAO 216-6 criteria and 
CEQ's context and intensity criteria. Based on this evaluation, NMFS 
determined that issuance of this IHA to USGS would not significantly 
impact the quality of the human environment and issued a FONSI. 
Accordingly, preparation of an EIS is not necessary. NMFS's 
determination and evaluation of the NAO 216-6 criteria and CEQ's 
context and intensity criteria are contained within the FONSI issued 
for this action.
    Comment 40: COA states that the NEPA document must be made 
available for public review and comment. COA states that the public was 
not offered an opportunity to comment on the proposed project until the 
issuance of the proposed IHA on June 23, 2014.
    Response: NMFS notes that USGS's draft EA was posted on the USGS 
Web site for a 30-day public comment period from May 20 to June 20, 
2014. The draft EA was also posted on the NSF Web site. USGS received 
no public comment or inquiries on the draft EA during that period. NMFS 
also made the draft EA available to the public on the NMFS permit Web 
site (https://www.nfms.noaa.gov/per/permits/incidental.htm#applications) 
concurrently with the release of the Federal Register notice for the 
proposed IHA (79 FR 35642, June 23, 2014). NMFS shared comments on the 
draft EA received during the 30-day IHA comment period with USGS and 
NSF. USGS considered the public comments received during the 30-day IHA 
comment period in preparing the final IHA. NMFS also considered all 
public comments received in evaluating the sufficiency of the USGS EA 
and in preparing the final IHA.
    Comment 41: COA states that the EA does not devote sufficient 
discussion to alternatives including alternative times of year and 
additional monitoring activities.
    Response: The NEPA and the implementing CEQ regulations (40 CFR 
parts 1500-1508) require consideration of alternatives to proposed 
major federal actions and NAO 216-6 provides agency policy and guidance 
on the consideration of alternatives to our proposed action. An EA must 
consider all reasonable alternatives, including the No Action 
alternative. This provides a baseline analysis against which we can 
compare the other alternatives.
    The USGS EA addresses the potential environmental impacts of three 
choices available to us under section 101(a)(5)(D) of the MMPA, namely:
     The proposed seismic survey and the issuance of an 
associated IHA;
     A corresponding seismic survey at an alternative time, 
along with issuance of an associated IHA; or
     A no action alternative, with no issuance of an IHA and no 
seismic survey.
    To warrant detailed evaluation as a reasonable alternative, an 
alternative must meet our purpose and need. In this case, an 
alternative meets the purpose and need if it satisfied the requirements 
under section 101(a)(5)(D) of the MMPA. Each alternative must also be 
feasible and reasonable in accordance with the President's Council on 
Environmental Quality regulations (40 CFR Sec. Sec.  1500-1508). NMFS 
evaluated potential alternatives against these criteria.
    NMFS disagrees with the commenter's assessment that the USGS EA did 
not sufficiently evaluate alternatives, including alternative times of 
year. The USGS EA considered, but rejected, conducting the seismic 
survey at a different time of the year, along with issuance of an 
associated IHA. Regarding seasonal distributions of marine mammals, the 
EA considers seasonal distributions through descriptions presented in 
Chapter 3.

[[Page 52145]]

The EA concludes that ``[m]ost marine mammal species are year-round 
residents in the North Atlantic, based on the number of OBIS sightings 
in the Study Area and adjacent waters, so altering the timing of the 
proposed project likely would result in no net benefits for those 
species'' (see USGS EA section 4.4).
    With respect to scheduling the survey during winter, the EA states 
that weather conditions in the Atlantic Ocean and ship schedules also 
constrain the possible time window of the seismic survey to May through 
September. Because of generally higher sea states in winter, winter is 
an unsafe time for conducting experiments when ship maneuverability is 
limited, as it is towing an 8 km long streamer. Scheduling the seismic 
survey in mid-summer when daylight hours are maximized and sea states 
are generally minimal facilitates observations and identifications of 
marine wildlife.
    The EA concludes that the proposed dates for the cruise under the 
Preferred Alternative (August to September 2014 and April to August 
2015) are the most suitable, from a logistical perspective, for the 
Langseth, essential equipment and the participating scientists and 
personnel. The 2014 seismic survey is also scheduled so that the 
subsequent proposed seismic survey (GeoPRISMS/ENAM) on the Langseth 
scheduled from mid-September to early October does not interfere with 
North Atlantic right whale migrations. If the IHA is issued for another 
period, it could result in significant delay and disruption not only of 
the proposed seismic survey, but of subsequent studies that are planned 
on the Langseth for 2014, 2015, and beyond.
    Regarding the mitigation and monitoring measures suggested by COA, 
NMFS determined that the measures were not feasible or already 
required. Pre-survey observations and post-survey monitoring are not 
feasible due to the length of the tracklines, the distance of the 
action area from shore, and the Langseth's schedule. With respect to 
aerial surveys, see the response to comment 23. With respect to 
exclusion zones and sound thresholds, see the responses to comments 31 
to 36. With respect to activity during low light and nighttime 
conditions, see the response to comment 27. With respect to night 
vision technology, the IHA requires that PSVOs have access to night 
vision devices. For additional required mitigation measures, see the 
``Mitigation'' section below. NMFS determined, based on the best 
available data, that the mitigation and monitoring measures required by 
the IHA are the most feasible and effective measures capable of 
implementation by USGS during the planned seismic survey.
    Comment 42: COA states that in its discussion of the No Action 
alternative, the EA does not adequately qualify the benefits of the No 
Action alternative, in which the proposed action would not proceed and 
marine mammals would not be subject to harassment, in relation to the 
costs.
    Response: Concerning the benefits of the No Action alternative, the 
EA addresses this concern in section 4.5, where it states that ``the No 
Action alternative would result in no disturbance to marine mammals or 
sea turtles attributable to the planned seismic survey.'' Concerning 
the costs of the No Action alternative, the EA states that the No 
Action alternative would not meet the purpose and need for the proposed 
activities. As stated in the EA, ``[t]he U.S. would not be able to 
define the ECS and therefore not be able to exercise its sovereign 
rights over the seafloor and sub-seafloor because it would lack the 
data to determine the extent of its sovereign rights. Nor would USGS 
have an important data set to contribute to its accurate assessment of 
submarine landslide and tsunami hazards along the east coast'' (USGS 
EA, section 4.5).
    Comment 43: NRDC et al. state that USGS fails to adequately assess 
cumulative impacts of the activity. NRDC et al. state that NMFS and 
USGS must analyze both auditory and behavioral impacts of repeated 
exposure to noise pollution on a population that may alter behavior. 
NRDC et al. also state that the cumulative impact analysis must include 
a full evaluation of the cumulative impacts of oil and gas seismic 
surveys planned for and anticipated in the Atlantic; the L-DEO seismic 
survey off New Jersey and other NSF or USGS planned seismic surveys; 
and military and testing sonar activities.
    Response: NMFS disagrees with commenters' assessment. The USGS EA 
and the documents it incorporates analyze the effects of the seismic 
survey in light of other human activities in the study area, including 
the activities the commenters reference. The NSF/USGS PEIS, which the 
USGS EA tiers to, also analyzes the cumulative impacts of NSF-funded 
and USGS-conducted seismic surveys. The USGS EA, which NMFS adopted, 
concludes that the impacts of USGS's proposed seismic survey in the 
Atlantic Ocean are expected to be more than minor and short-term with 
no potential to contribute to cumulatively significant impacts. NMFS 
independently reviewed USGS's EA and concluded that the impacts 
evaluated by USGS are substantially the same as the impacts of the 
alternatives considered in issuing an IHA, under the MMPA, for USGS's 
seismic survey. As explained in NMFS' FONSI, NMFS expect the following 
combination of activities to result in no more than minor and short-
term impacts to marine mammals in the survey area in terms of overall 
disturbance effects: (1) NMFS's issuance of an IHA with prescribed 
mitigation and monitoring measures for the seismic survey; (2) past, 
present, and reasonably foreseeable future research in the northwest 
Atlantic Ocean off the Eastern Seaboard; (3) vessel traffic, noise, and 
collisions; (4) commercial and recreational fishing; (5) military 
activities; (6) oil and gas activities; and (7) submarine cable 
installation activities.
    NMFS notes that section 4.1.2.3 of the NSF/USGS PEIS specifically 
addresses the cumulative impacts of repeated exposure to noise, 
including potential exposure to multiple NSF or USGS seismic surveys 
and potential exposure to NSF or USGS seismic surveys and other 
activities that produce underwater noise. It states that ``no impacts 
are anticipated at the regional population level. The few, relatively 
short, localized NSF or USGS seismic surveys in the context of the 
ocean-region basis would not have more than a negligible cumulative 
effect on marine mammals at the individual or population level. 
Possible exceptions are local non-migratory populations or populations 
highly concentrated in one area at one of year (e.g., for breeding). 
However, the latter scenario would be mitigated by timing and locating 
proposed seismic surveys to avoid sensitive seasons and/or locations 
important to marine mammals, especially those that are ESA-listed.'' It 
further states that ``there is no evidence that [short-term behavioral 
changes], whether considered alone or in succession, result in long-
term adverse impacts to individuals or populations assuming important 
habitats or activities are not disturbed. Furthermore, long-migrating 
marine mammals in particular have undoubtedly been exposed to many 
anthropogenic underwater sound activities for decades in all ocean 
basins. Many of these populations continue to grow despite a 
preponderance of anthropogenic marine activities that may have been 
documented to disturb some individuals behaviorally (e.g., Hildebrand, 
2004).''

[[Page 52146]]

General Concerns

    Comment 44: COA states that NMFS must take best available science 
and the precautionary principle into account.
    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 available science regarding the biology of animals 
affected and the propagation of underwater sounds from sources during 
the seismic survey. This information is supported by USGS's IHA 
application and EA.
    Comment 45: NRDC et al. state that USGS and NMFS fail to adequately 
assess impacts on the North Atlantic right whale. NRDC et al. also 
state that the seismic survey does not include any time-area closures 
to reduce impacts on North Atlantic right whales, nor does it provide 
any quantitative or even detailed qualitative analysis of masking 
effects or other cumulative, sub-lethal impacts on North Atlantic right 
whales.
    Response: NMFS disagrees with the NRDC et al.'s comments and has 
adequately assessed impacts to the North Atlantic right whale. The 
seismic survey's tracklines avoid the northeast Atlantic Ocean 
designated critical habitat by approximately 190 km (102.6 nmi) and 
avoid the southeast Atlantic Ocean designated critical habitat by 
approximately 519 km (280.2 nmi). The probability of vessel and marine 
mammal interactions (e.g., ship strike) is highly unlikely due to the 
low density of right whales and other mysticetes in the survey area, as 
well as the Langseth's slow operational speed, which is typically 4.5 
kts (8.5 km/hr, 5.3 mph). Outside of airgun operations, the Langseth's 
cruising speed will be approximately 10 kts (18.5 km/hr, 11.5 mph), 
which is generally below the speed at which studies have noted reported 
increases of marine mammal injury or death (Laist et al., 2001). 
Responses 5, 21, and 36 provide responses to concerns about masking 
effects and the use of the multi-beam echosounder.
    Considering the rarity and conservation status for the North 
Atlantic right whale, the airguns will be shut-down immediately in the 
unlikely event that this species is observed, regardless of the 
distance from the Langseth. The airgun array shall not resume firing 
(with ramp-up) until 30 minutes after the last documented North 
Atlantic right whale visual sighting. This mitigation measure is a 
requirement in the IHA issued to USGS.
    Comment 46: NRDC et al. states that NMFS fails to analyze impacts 
on fish and other species of concern. NRDC et al. state that the 
proposed IHA assumes without support that effects on both fish and 
fisheries would be localized and minor. NRDC et al. urges NMFS to 
improve its analysis.
    Response: NMFS disagrees with NRDC et al.'s assessment. NMFS 
adopted the USGS EA, which describes marine fish in section 3.7, EFH in 
section 3.8.2, and considers the impacts of the survey on fish, EFH and 
fisheries in sections 4.2.5 and 4.2.7. The USGS EA tiers to the NSF/
USGS PEIS, which also analyzes the impacts of seismic surveys on fish. 
All of the studies cited by NRDC et al. regarding fish are cited in the 
NSF/USGS PEIS (Appendix D) together with numerous additional studies 
that document the limited and sometimes conflicting knowledge about the 
acoustic capabilities of fish and the effects of airgun sound on fish. 
The EA's conclusion that ``the direct effects of the seismic survey and 
its noise may have minor effects on marine fisheries that are generally 
reversible, of limited duration, magnitude, and geographic extent when 
considering individual fish, and not measurable at the population 
level'' is well supported. NMFS also evaluated the impacts of the 
seismic survey on fish and invertebrates in the notice of the proposed 
IHA (79 FR 35642, June 23, 2014). NMFS included a detailed discussion 
of the potential effects of this action on marine mammal habitat, 
including physiological and behavioral effects on marine fish and 
invertebrates.
    Comment 47: NRDC et al. states that USGS did not provide any 
meaningful analysis of the proposed action's impacts on essential fish 
habitat (EFH). NRDC et al. states that NMFS has a statutory obligation 
to consult on the impact of federal activities on EFH under the 
Magnuson-Stevens Fishery Conservation and Management Act (MSA). NRDC et 
al. states that the EFH consultation for the action is inadequate.
    Response: NMFS disagrees with the commenters' assessment. As 
discussed in the response to comment 46, the NSF/USGS PEIS, the USGS 
EA, and other environmental assessment that the USGS EA incorporates 
identify EFH within the project area and evaluate the impacts of the 
seismic survey on EFH. USGS EA (see section 3.8.2) and the NSF/USGS 
PEIS (see section 3.3.2.1) discuss the seismic survey's impacts on EFH. 
In the site-specific EA, USGS determined that the seismic survey is 
restricted to the surface waters and thus there would be no physical 
contact or disturbance with EFH. NMFS adopted the USGS EA after 
evaluating it for sufficiency.
    USGS requested a determination from the NMFS, Habitat Conservation 
Divisions of the Southeast Regional and Greater Atlantic Regional 
Fisheries Offices, whether the seismic survey required a formal 
consultation. In a letter dated June 20, 2014, NMFS stated that in 
accordance with the MSA, EFH has been identified and described in the 
EEZ portions of the study area by the New England, Mid-Atlantic and 
South Atlantic Fishery Management Councils and NMFS. The letter 
acknowledged that USGS and NSF, as the federal action agency for this 
action, determined the proposed seismic survey may result in minor 
adverse impacts to water column habitats identified and described as 
EFH. NMFS stated that the Habitat Conservation Divisions in the 
Southeast Regional and Greater Atlantic Regional Fisheries Offices 
reviewed that analysis and the proposed mitigation measures contained 
in the NSF/USGS PEIS and the EA prepared for this action. Upon 
considering the design and nature of the seismic survey, NMFS had no 
EFH conservation recommendations to provide pursuant to section 
305(b)(2) of the MSA. NMFS stated additional research and monitoring is 
needed to gain a better understanding of the potential effects these 
activities may have on EFH, federally managed species, their prey and 
other NOAA trust resources, and recommended that this type of research 
should be a component of future NSF-funded seismic surveys. USGS agree 
that this is an area of needed research.
    The issuance of an IHA and the mitigation and monitoring measures 
required by the IHA would not affect ocean and coastal habitat or EFH. 
Therefore, NMFS, Office of Protected Resources, Permits and 
Conservation Division has determined that an EFH consultation is not 
required.
    Comment 48: NRDC et al. states that NMFS must fully comply with the 
ESA and develop a robust Biological Opinion based on the best available 
science. They state that NMFS should evaluate the impact of the seismic 
survey on new sea turtle and potential right whale critical habitat. 
They further urge NMFS to establish more stringent mitigation measures 
to protect ESA-listed species than are currently proposed by the IHA.
    Response: Section 7(a)(2) of the ESA requires that each federal 
agency insure that any action authorized, funded, or carried out by 
such agency is not likely to jeopardize the continued existence of any 
endangered or threatened species or result in the destruction or 
adverse modification of critical habitat of such species. Of the 
species of marine mammals that may occur in the action

[[Page 52147]]

area, several are listed as endangered under the ESA, including the 
North Atlantic right, humpback, sei, fin, blue, and sperm whales. 
Designated critical habitat for the Northwest Atlantic Ocean Distinct 
Population Segment of loggerhead sea turtles (Caretta caretta) also 
occur in the action area.
    Under section 7 of the ESA, USGS 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, 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 effects of the proposed actions on threatened 
and endangered species as well as designated critical habitat. The 
Biological Opinion concluded that both actions (i.e., the USGS seismic 
survey and NMFS's issuance of an IHA) are not likely to jeopardize the 
existence of cetaceans and sea turtles and would have no effect on 
critical habitat. NMFS's Office of Protected Resources, Endangered 
Species Act Interagency Cooperation Division relied on the best 
scientific and commercial data available in conducting its analysis.
    Although critical habitat is designated for the North Atlantic 
right whale, no critical habitat for North Atlantic right whales occurs 
in the action area. The North Atlantic right whale critical habitat in 
the northeast Atlantic Ocean can be found online at: https://
www.nmfs.noaa.gov/pr/pdfs/criticalhabitat/
nrightwhalene.pdf. The North Atlantic right whale 
critical habitat in the southeast Atlantic Ocean can be found online 
at: https://www.nmfs.noaa.gov/pr/pdfs/criticalhabitat/
nrightwhalese.pdf. The survey trackline that has the 
closest approach to the northeast Atlantic Ocean designated critical 
habitat is approximately 190 km (102.6 nmi) from the area. The 
trackline that has the closest approach to the southeast Atlantic Ocean 
designated critical habitat is approximately 519 km (280.2 nmi) from 
the area. The Biological Opinion considers the distribution, migration 
and movement, general habitat, and designated critical habitat of the 
North Atlantic right whale in its analysis.
    NMFS's Office of Protected Resources, Permits and Conservation 
Division also considered the conservation status and habitat of ESA-
listed marine mammals. Included in the IHA are special procedures for 
situations or species of concern (see ``Mitigation'' section below). If 
a North Atlantic right whale is visually sighted during the survey, the 
airgun array must be shut-down regardless of the distance of the 
animal(s) to the sound source. The array will not resume firing until 
30 minutes after the last documented whale visual sighting. 
Concentrations of humpback, sei, fin, blue, and/or sperm whales will be 
avoided if possible (i.e., exposing concentrations of animals to 160 
dB), and the array will be powered-down if necessary. For purposes of 
the survey, a concentration or group of whales will consist of six or 
more individuals visually sighted that do not appear to be traveling 
(e.g., feeding, socializing, etc.). NMFS's Office of Protected 
Resources, Endangered Species Act Interagency Cooperation Division 
issued an Incidental Take Statement (ITS) incorporating the 
requirements of the IHA as Terms and Conditions of the ITS. Compliance 
with the ITS is likewise a mandatory requirement of the IHA. NMFS's 
Office of Protected Resources, Permits and Conservation Division has 
determined that the mitigation measures required by the IHA provide the 
means of effecting the least practicable impact on species or stocks 
and their habitat, including ESA-listed species.
    Comment 49: NRDC et al. states that the Coastal Zone Management Act 
(CZMA) requires that applicants for federal permits to conduct an 
activity affecting a natural resource of the coastal zone of a state 
``shall provide in the application to the licensing or permitting 
agency a certification that the proposed activity complies with the 
enforceable policies of the state's approved program and that such 
activity will be conducted in a manner consistent with the program.'' 
NRDC et al. states that the marine mammals and fish that will be 
affected by the seismic survey are all ``natural resources'' protected 
by the coastal states' coastal management program, and that states 
should be given the opportunity to review the IHA for consistency with 
their coastal management programs.
    Response: As the lead federal agency for the planned seismic 
survey, USGS considered whether the action would have effects on the 
coastal resources of any state along the U.S. Eastern Seaboard. As 
concluded in the USGS EA, any potential impacts from the seismic survey 
would mainly be to marine species in close proximity to the vessel and 
would be of a short duration and temporary in nature. Because the 
planned seismic survey will occur in deep water and long distances from 
the U.S. East Coast, USGS concluded the seismic survey would have no 
effect on coastal zone resources. The seismic survey would occur in 
approximately 2,000 to 5,000 m water depth, and most of the tracklines 
would occur beyond 463 to 648.2 km (250 to greater than 350 nmi) 
offshore. The closest approach to land will be approximately 170 km (92 
nmi). USGS reviewed the Federal Consistency Listings for the states 
along the East Coast and determined that the action is not listed. USGS 
did not receive a request from any state for a consistency review of 
the unlisted activity. Therefore, it was concluded that USGS met all of 
the responsibilities under the CZMA. USGS and NSF also discussed the 
proposed seismic survey with the NOAA Office of Ocean and Coastal 
Resource Management (OCRM) to confirm the agencies responsibilities 
under CZMA for the planned unlisted activity.
    Comment 50: One private citizen opposed the issuance of an IHA by 
NMFS and the conduct of the seismic survey in the northwest Atlantic 
Ocean off the Eastern Seaboard, August to September 2014 and April to 
August 2015, by USGS. The commenter states that NMFS should protect 
marine life from harm.
    Response: As described in detail in the notice for the proposed IHA 
(79 FR 35642, June 23, 2014), as well as in this document, NMFS does 
not believe that USGS's seismic survey would cause injury, serious 
injury, or mortality to marine mammals, and no take by injury, serious 
injury, or mortality is authorized. The required monitoring and 
mitigation measures that USGS will implement during the seismic survey 
will further reduce the potential impacts on marine mammals to the 
lowest levels practicable. NMFS anticipates only behavioral disturbance 
to occur during the conduct of the seismic survey.

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

    Forty-five species of marine mammal (37 cetaceans [whales, 
dolphins, and porpoises] including 30 odontocetes and 7 mysticetes, 7 
pinnipeds [seals and sea lions], and 1 sirenian [manatees]) are known 
to occur in the western North Atlantic Ocean study area (Read et al., 
2009; Waring et al., 2013). Of those 45 species of marine mammals, 34 
cetaceans could be found or are likely to occur in the study area 
during the spring/summer/fall months. Several of

[[Page 52148]]

these species are listed as endangered under the U.S. Endangered 
Species Act of 1973 (ESA; 16 U.S.C. 1531 et seq.), including the North 
Atlantic right (Eubalaena glacialis), humpback (Megaptera 
novaeangliae), sei (Balaenoptera borealis), fin (Balaenoptera 
physalus), blue (Balaenoptera musculus), and sperm (Physeter 
macrocephalus) whales. The white-beaked dolphin (Lagenorhynchus 
albirostris) generally occurs north of the of the planned study area 
and no take has been authorized. The harbor porpoise (Phocoena 
phocoena) usually occur in shallow nearshore waters, but occasionally 
travel over deep offshore waters. The four pinniped species (harbor 
[Phoca vitulina], harp [Phoca groenlandica], gray [Halichoerus grypus], 
and hooded [Cystophora cristata] seals) are also considered coastal 
species (any sightings would be considered extralimital) and are not 
known to occur in the deep waters of the survey area. No pinnipeds are 
expected to be present in the planned study area, and not take has been 
authorized for pinnipeds. The West Indian manatee (Trichechus manatus 
latirostris) is listed as endangered under the ESA and is managed by 
the U.S. Fish and Wildlife Service and is not considered further in 
this IHA notice.
    General information on the taxonomy, ecology, distribution, 
seasonality and movements, and acoustic capabilities of marine mammals 
are given in sections 3.6.1, 3.7.1, and 3.8.1 of the NSF/USGS PEIS. The 
general distribution of mysticetes, odontocetes, and pinnipeds in the 
North Atlantic Ocean is discussed in sections 3.6.3.4, 3.7.3.4, and 
3.8.3.4 of the NSF/USGS PEIS, respectively. In addition, Section 3.1 of 
the ``Atlantic OCS Proposed Geological and Geophysical Activities Mid-
Atlantic and South Atlantic Planning Areas Draft Programmatic 
Environmental Impact Statement'' (Bureau of Ocean Energy Management, 
2012) reviews similar information for all marine mammals that may occur 
within the study area.
    Various systematic surveys have been conducted throughout the 
western North Atlantic Ocean, including within sections of the study 
area. Records from the Ocean Biogeographic Information System (OBIS) 
database hosted by Rutgers University and Duke University (Read et al., 
2009) were used as the main source of information. The database 
includes survey data collected during the Cetaceans and Turtle 
Assessment Program (CeTAP) conducted between 1978 and 1982 that 
consists of both aerial and vessel-based surveys between Cape Hatteras, 
North Carolina, and the Gulf of Maine. The database also includes 
survey data collected during the NMFS Northeast Fisheries Science 
Center and Southeast Fisheries Science Center stock assessment surveys 
conducted in 2004 (surveys between Nova Scotia, Canada, and Florida).
    No known current regional or stock abundance estimates are 
available in the study area of the northwest Atlantic Ocean for the 
Bryde's whale (Balaenoptera edeni), Fraser's (Lagenodelphis hosei), 
spinner (Stenella longirostris), and Clymene dolphin (Stenella 
clymene), and melon-headed (Peponocephala electra), pygmy killer 
(Feresa attenuata), false killer (Pseudorca crassidens), and killer 
whales (Orcinus orca). Although NMFS does not have current regional 
population or stock abundance estimates for these species in the 
northwest Atlantic Ocean, NMFS provides below general information about 
their global distribution and occurrence in the survey area.
    Bryde's whales are distributed worldwide in tropical and sub-
tropical waters. In the western North Atlantic Ocean, Bryde's whales 
are reported from off the southeastern U.S. and the southern West 
Indies to Cabo Frio, Brazil (Leatherwood and Reeves, 1983). No stock of 
Bryde's whales has been identified in U.S. waters of the Atlantic 
coast.
    Fraser's dolphins are distributed worldwide in tropical waters and 
are assumed to be part of the cetacean fauna of the tropical western 
North Atlantic (Perrin et al., 1994). There are no abundance estimates 
for either the western North Atlantic or the northern Gulf of Mexico 
stocks. The western North Atlantic population is provisionally being 
considered a separate stock for management purposes, although there is 
currently no information to differentiate this stock from the northern 
Gulf of Mexico stock. The numbers of Fraser's dolphins off the U.S. or 
Canadian Atlantic coast are unknown, and seasonal abundance estimates 
are not available for this stock, since it was rarely seen in any 
surveys. The population size for Fraser's dolphins is unknown; however, 
about 289,000 animals occur in the eastern tropical Pacific Ocean 
(Jefferson et al., 2008).
    Spinner dolphins are distributed in oceanic and coastal tropical 
waters (Leatherwood et al., 1976). This is presumably an offshore, 
deep-water species, and its distribution in the Atlantic is poorly 
known (Schmidly, 1981; Perrin and Gilpatrick, 1994). The western North 
Atlantic population of spinner dolphins is provisionally being 
considered a separate stock for management purposes, although there is 
currently no information to differentiate this stock from the northern 
Gulf of Mexico stock. The numbers of spinner dolphins off the U.S. or 
Canadian Atlantic coast are unknown, and seasonal abundance estimates 
are not available for this stock since it was rarely seen in any of the 
surveys.
    The Clymene dolphin is endemic to tropical and sub-tropical waters 
of the Atlantic (Jefferson and Curry, 2003). The western North Atlantic 
population of Clymene dolphins is provisionally considered a separate 
stock for management purposes, although there is currently no 
information to differentiate this stock from the northern Gulf of 
Mexico stock. The numbers of Clymene dolphins off the U.S. or Canadian 
Atlantic coast are unknown, and seasonal abundance estimates are not 
available for this species since it was rarely seen in any surveys. The 
best abundance estimate for the Clymene dolphin in the western North 
Atlantic was 6,086 in 2003 and represents the first and only estimate 
to date for this species in the U.S. Atlantic EEZ; however this 
estimate is older than eight years and is deemed unreliable (Wade and 
Angliss, 1997; Mullin and Fulling, 2003).
    The melon-headed whale is distributed worldwide in tropical to sub-
tropical waters (Jefferson et al., 1994). The western North Atlantic 
population is provisionally being considered a separate stock from the 
northern Gulf of Mexico stock. The numbers of melon-headed whales off 
the U.S. or Canadian Atlantic coast are unknown, and seasonal abundance 
estimates are not available for this stock, since it was rarely seen in 
any surveys.
    The pygmy killer whale is distributed worldwide in tropical to sub-
tropical waters and is assumed to be part of the cetacean fauna of the 
tropical western North Atlantic (Jefferson et al., 1994). The western 
North Atlantic population of pygmy killer whales is provisionally being 
considered one stock for management purposes. The numbers of pygmy 
killer whales off the U.S. or Canadian Atlantic coast are unknown, and 
seasonal abundance estimates are not available for this stock, since it 
was rarely seen in any surveys.
    The false killer whale is distributed worldwide throughout warm 
temperate and tropical oceans (Leatherwood and Reeves, 1983). No stock 
has been identified for false killer whales in U.S. waters off the 
Atlantic coast.
    Killer whales are characterized as uncommon or rare in waters of 
the U.S. Atlantic EEZ (Katona et al., 1988). Their

[[Page 52149]]

distribution, however, extends from the Arctic ice-edge to the West 
Indies, often in offshore and mid-ocean areas. The size of the western 
North Atlantic stock population off the eastern U.S. coast is unknown. 
No information on stock differentiation for the Atlantic Ocean 
population exists, although an analysis of vocalizations of killer 
whales from Iceland and Norway indicated that whales from these areas 
may represent different stocks (Moore et al., 1988). There are 
estimated to be at least approximately 92,500 killer whales worldwide 
(i.e., 80,000 south of Antarctic Convergence, 445 in Norway, 8,500 in 
eastern tropical Pacific Ocean, 1,500 in North America coastal waters, 
and 2,000 in Japanese waters) (Jefferson et al., 2008).
    Table 3 (below) presents information on the abundance, 
distribution, population status, and conservation status of the species 
of marine mammals that may occur in the planned study area during 
August to September 2014 and April to August 2015.

 Table 3--The Habitat, Occurrence, Range, Abundance, and Conservation Status of Marine Mammals That May Occur in or Near the Seismic Survey Area in the
                                                                Northwest Atlantic Ocean
                                                               [Off the Eastern Seaboard]
                                          [See text and Table 3 in USGS's IHA application for further details]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                    Population estimate
                                                                               Range in Atlantic       in the North
             Species                      Habitat            Occurrence              Ocean           Atlantic region/       ESA \1\         MMPA \2\
                                                                                                      stock/other \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
    North Atlantic right whale     Pelagic, shelf and    Regular...........  Canada to Florida...  455/455 (Western      EN             D.
     (Eubalaena glacialis).         coastal.                                                        Atlantic stock).
    Humpback whale (Megaptera      Mainly nearshore,     Regular...........  Canada to Caribbean.  11,600 \4\/823 (Gulf  EN             D.
     novaeangliae).                 banks.                                                          of Maine stock).
    Minke whale (Balaenoptera      Pelagic and coastal.  Regular...........  Arctic to Caribbean.  138,000 \5\/20,741    NL             NC.
     acutorostrata).                                                                                (Canadian East
                                                                                                    Coast stock).
    Bryde's whale (Balaenoptera    Coastal, offshore...  Rare..............  40[deg] North to      NA/NA/33 (Northern    NL             NC.
     edeni).                                                                  40[deg] South.        Gulf of Mexico
                                                                                                    stock)/20,000 to
                                                                                                    30,000 \16\ (North
                                                                                                    Pacific Ocean).
    Sei whale (Balaenoptera        Primarily offshore,   Rare..............  Canada to New Jersey  10,300 \6\/357 (Nova  EN             D.
     borealis).                     pelagic.                                                        Scotia stock).
    Fin whale (Balaenoptera        Continental slope,    Regular...........  Canada to North       26,500 \7\/3,522      EN             D.
     physalus).                     pelagic.                                  Carolina.             (Western North
                                                                                                    Atlantic stock).
    Blue whale (Balaenoptera       Pelagic, shelf,       Rare..............  Arctic to Florida...  855 \8\/NA (Western   EN             D.
     musculus).                     coastal.                                                        North Atlantic
                                                                                                    stock, 440 minimum).
Odontocetes:
    Sperm whale (Physeter          Pelagic, slope,       Regular...........  Canada to Caribbean.  13,190 \9\/2,288      EN             D.
     macrocephalus).                canyons, deep sea.                                              (North Atlantic
                                                                                                    stock).
    Pygmy sperm whale (Kogia       Deep waters off       Rare..............  Massachusetts to      NA/3,785 (Western     NL             NC.
     breviceps).                    shelf.                                    Florida.              North Atlantic
                                                                                                    stock).
    Dwarf sperm whale (Kogia       Deep waters off       Rare..............  Massachusetts to                            NL             NC.
     sima).                         shelf.                                    Florida.
    Cuvier's beaked whale          Pelagic, slope,       Rare..............  Canada to Caribbean.  NA/6,532 (Western     NL             NC.
     (Ziphius cavirostris).         canyons.                                                        North Atlantic
                                                                                                    stock).
    Northern bottlenose whale      Pelagic.............  Rare..............  Arctic to New Jersey  40,000 \10\/NA        NL             NC.
     (Hyperoodon ampullatus).                                                                       (Western North
                                                                                                    Atlantic stock).
    True's beaked whale            Pelagic, slope,       Rare..............  Canada to Bahamas...  NA/7,092 (Western     NL             NC.
     (Mesoplodon mirus).            canyons.             Rare..............  Canada to Florida...   North Atlantic       NL             NC.
    Gervais' beaked whale          Pelagic, slope,       Rare..............  Canada to Florida...   stock).              NL             NC.
     (Mesoplodon europaeus).        canyons.
    Sowerby's beaked whale         Pelagic, slope,
     (Mesoplodon bidens).           canyons.
    Blainville's beaked whale      Pelagic, slope,       Rare..............  Canada to Florida...                        NL             NC.
     (Mesoplodon densirostris).     canyons.
    Bottlenose dolphin (Tursiops   Coastal, oceanic,     Regular...........  Canada to Florida...  NA/77,532 (Western    NL             NC.
     truncatus).                    shelf break.                                                    North Atlantic
                                                                                                    Offshore stock).
    Atlantic white-sided dolphin   Shelf and slope.....  Regular...........  Greenland to North    10,000 to 100,000s    NL             NC.
     (Lagenorhynchus acutus).                                                 Carolina.             \11\/48,819
                                                                                                    (Western North
                                                                                                    Atlantic stock).
    White-beaked dolphin           Shelf, offshore.....  Rare..............  Cape Cod to Canada    7,800 \16\ (North     NL             NC.
     (Lagenorhynchus albirostris).                                            and Europe.           Sea)/2,003 (Western
                                                                                                    North Atlantic
                                                                                                    stock).
    Fraser's dolphin               Shelf and slope.....  Rare..............  North Carolina to     NA/NA (Western North  NL             NC.
     (Lagenodelphis hosei).                                                   Florida.              Atlantic stock)/
                                                                                                    289,000 \16\
                                                                                                    (eastern tropical
                                                                                                    Pacific Ocean).
    Atlantic spotted dolphin       Shelf, offshore.....  Regular...........  Massachusetts to      NA/44,715 (Western    NL             NC.
     (Stenella frontalis).                                                    Caribbean.            North Atlantic
                                                                                                    stock).
    Pantropical spotted dolphin    Coastal, shelf,       Regular...........  Massachusetts to      NA/3,333 (Western     NL             NC.
     (Stenella attenuata).          slope.                                    Florida.              North Atlantic
                                                                                                    stock).
    Striped dolphin (Stenella      Off continental       Regular...........  Canada to Caribbean.  NA/54,807 (Western    NL             NC.
     coeruleoalba).                 shelf, convergence                                              North Atlantic
                                    zones, upwelling.                                               stock).

[[Page 52150]]

 
    Spinner dolphin (Stenella      Mainly nearshore....  Rare..............  Maine to Caribbean..  NA/NA (Western North  NL             NC.
     longirostris).                                                                                 Atlantic stock)/
                                                                                                    11,441 (Northern
                                                                                                    Gulf of Mexico
                                                                                                    stock)/1,250,000
                                                                                                    \16\ (eastern
                                                                                                    tropical Pacific
                                                                                                    Ocean).
    Clymene dolphin (Stenella      Coastal, shelf,       Rare..............  North Carolina to     NA/NA (Western North  NL             NC.
     clymene).                      slope.                                    Florida.              Atlantic stock--
                                                                                                    6,086 in 2003)/129
                                                                                                    (Northern Gulf of
                                                                                                    Mexico stock).
    Short-beaked common dolphin    Shelf, pelagic,       Regular...........  Canada to Georgia...  NA/173,486 (Western   NL             NC.
     (Delphinus delphis).           seamounts.                                                      North Atlantic
                                                                                                    stock).
    Rough-toothed dolphin (Steno   Pelagic.............  Rare..............  New Jersey to         NA/271 (Western       NL             NC.
     bredanensis).                                                            Florida.              North Atlantic
                                                                                                    stock).
    Risso's dolphin (Grampus       Shelf, slope,         Regular...........  Canada to Florida...  NA/18,250 (Western    NL             NC.
     griseus).                      seamounts.                                                      North Atlantic
                                                                                                    stock).
    Melon-headed whale             Deep waters off       Rare..............  North Carolina to     NA/NA (Western North  NL             NC.
     (Peponocephala electra).       shelf.                                    Florida.              Atlantic stock)/
                                                                                                    2,235 (Northern
                                                                                                    Gulf of Mexico
                                                                                                    stock)/45,000 \16\
                                                                                                    (eastern tropical
                                                                                                    Pacific Ocean).
    Pygmy killer whale (Feresa     Pelagic.............  Rare..............  NA..................  NA/NA (Western North  NL             NC.
     attenuata).                                                                                    Atlantic stock)/152
                                                                                                    (Northern Gulf of
                                                                                                    Mexico stock)/
                                                                                                    39,000 \16\
                                                                                                    (eastern tropical
                                                                                                    Pacific Ocean).
    False killer whale (Pseudorca  Pelagic.............  Rare..............  NA..................  NA/NA/777 in 2003-    NL             NC.
     crassidens).                                                                                   2004 (Northern Gulf
                                                                                                    of Mexico stock).
    Killer whale (Orcinus orca)..  Pelagic, shelf,       Rare..............  Arctic to Caribbean.  NA/NA (Western North  NL             NC.
                                    coastal.                                                        Atlantic stock)/28
                                                                                                    (Northern Gulf of
                                                                                                    Mexico stock)/At
                                                                                                    least ~92,500 \16\
                                                                                                    Worldwide.
    Short-finned pilot whale       Mostly pelagic, high  Regular...........  Massachusetts to      780,000 \12\/21,515   NL             NC.
     (Globicephala macrorhynchus).  relief.              ..................   Florida.              short-finned pilot   .............  ................
    Long-finned pilot whale        ....................  ..................  ....................   whale 26,535 long-   .............  ................
     (Globicephala melas).         ....................  Regular...........  ....................   finned pilot whale   NL             NC.
                                   Mostly pelagic......                      Canada to South        (Western North
                                                                              Carolina.             Atlantic stock).
    Harbor porpoise (Phocoena      Shelf, coastal,       Rare..............  Canada to North       ~500,000 \13\/79,883  NL             NC.
     phocoena).                     pelagic.                                  Carolina.             (Gulf of Maine/Bay
                                                                                                    of Fundy stock).
Pinnipeds:
    Harbor seal (Phoca vitulina    Coastal.............  Rare..............  Canada to North       NA/70,142 (Western    NL             NC.
     concolor).                                                               Carolina.             North Atlantic
                                                                                                    stock).
    Gray seal (Halichoerus         Coastal, pelagic....  Rare..............  Canada to North       NA/NA (Western North  NL             NC.
     grypus).                                                                 Carolina.             Atlantic stock,
                                                                                                    348,999 minimum in
                                                                                                    2012).
    Harp seal (Phoca               Ice whelpers,         Rare..............  Canada to New Jersey  8.6 to 9.6 million    NL             NC.
     groenlandica).                 pelagic.                                                        \14\/NA (Western
                                                                                                    North Atlantic
                                                                                                    stock, 8.3 million
                                                                                                    in 2012).
    Hooded seal (Cystophora        Ice whelpers,         Rare..............  Canada to Caribbean.  600,000/NA (Western   NL             NC.
     cristata).                     pelagic.                                                        North Atlantic
                                                                                                    stock, 592,100 in
                                                                                                    2007).
--------------------------------------------------------------------------------------------------------------------------------------------------------
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, NC = Not Classified.
\3\ NMFS Marine Mammal Stock Assessment Reports.
\4\ Best estimate for western North Atlantic 1992 to 1993 (IWC, 2014).
\5\ Best estimate for North Atlantic 2002 to 2007 (IWC, 2014).
\6\ Estimate for the Northeast Atlantic in 1989 (Cattanach et al., 1993).
\7\ Best estimate for North Atlantic 2007 (IWC, 2014).
\8\ Central and Northeast Atlantic 2001 (Pike et al., 2009).
\9\ North Atlantic (Whitehead, 2002).
\10\ Eastern North Atlantic (NAMMCO, 1995).
\11\ North Atlantic (Reeves et al., 1999).
\12\ Globicephala spp. combined, Central and Eastern North Atlantic (IWC, 2014).
\13\ North Atlantic (Jefferson et al., 2008).
\14\ Northwest Atlantic (DFO, 2012).
\15\ Northwest Atlantic (Andersen et al., 2009).
\16\ Jefferson et al. (2008).

    Further detailed information regarding the biology, distribution, 
seasonality, life history, and occurrence of these marine mammal 
species in the study area can be found in sections 3 and 4 of USGS's 
IHA application. NMFS has reviewed these data and determined them to be 
the best available scientific information for the purposes of the IHA.

[[Page 52151]]

Potential Effects of the Specified Activity on Marine Mammals

    This section includes a summary and discussion of the ways that the 
types of stressors associated with the specified activity (e.g., 
seismic airgun operation, vessel movement, gear deployment) have been 
observed to impact marine mammals. This discussion may also include 
reactions that we consider to rise to the level of a take and those 
that we do not consider to rise to the level of take (for example, with 
acoustics), we may include a discussion of studies that showed animals 
not reacting at all to sound or exhibiting barely measureable 
avoidance). This section is intended as a background of potential 
effects and does not consider either the specific manner in which this 
activity would be carried out or the mitigation that would be 
implemented, and how either of those would shape the anticipated 
impacts from this specific activity. The ``Estimated Take by Incidental 
Harassment'' section later in this document will include a quantitative 
analysis of the number of individuals that are expected to be taken by 
this activity. The ``Negligible Impact Analysis'' section will include 
the analysis of how this specific activity would impact marine mammals 
and will consider the content of this section, the ``Estimated Take by 
Incidental Harassment'' section, the ``Mitigation'' section, and the 
``Anticipated Effects on Marine Mammal Habitat'' section to draw 
conclusions regarding the likely impacts of this activity on the 
reproductive success or survivorship of individuals and from that on 
the affected marine mammal populations or stocks.
    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Based 
on available behavioral data, audiograms have been derived using 
auditory evoked potentials, anatomical modeling, and other data, 
Southall et al. (2007) designate ``functional hearing groups'' for 
marine mammals and estimate the lower and upper frequencies of 
functional hearing groups'' for marine mammals and estimate the lower 
and upper frequencies of functional hearing of the groups. The 
functional groups and the associated frequencies are indicated below 
(though animals are less sensitive to sounds at the outer edge of their 
functional range and most sensitive to sounds of frequencies within a 
smaller range somewhere in the middle of their functional hearing 
range):
     Low-frequency cetaceans (13 species of mysticetes): 
Functional hearing is estimated to occur between approximately 7 Hz and 
30 kHz;
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia spp., the franciscana [Pontoporia 
blainvillei], and four species of cephalorhynchids): Functional hearing 
is estimated to occur between approximately 200 Hz and 180 kHz; and
     Phocid pinnipeds in water: Functional hearing is estimated 
to occur between approximately 75 Hz and 100 kHz;
     Otariid pinnipeds in water: Functional hearing is 
estimated to occur between approximately 100 Hz and 40 kHz.
    As mentioned previously in this document, 34 marine mammal species 
(34 cetacean) are likely to occur in the seismic survey area. Of the 34 
cetacean species likely to occur in USGS's action area, 7 are 
classified as low-frequency cetaceans (i.e., North Atlantic right, 
humpback, minke, Bryde's, sei, fin, and blue whale), 24 are classified 
as mid-frequency cetaceans (i.e., sperm, Cuvier's, True's, Gervais', 
Sowerby's, Blainville's, Northern bottlenose, melon-headed, pygmy 
killer, false killer, killer, short-finned, and long-finned whale, 
bottlenose, Atlantic white-sided, Fraser's, Atlantic spotted, 
pantropical spotted, striped, spinner, Clymene, short-beaked common, 
rough-toothed, and Risso's dolphin), and 3 are classified as high-
frequency cetaceans (i.e., pygmy sperm and dwarf sperm whale and harbor 
porpoise) (Southall et al., 2007). A species' functional hearing group 
is a consideration when we analyze the effects of exposure to sound on 
marine mammals.
    Acoustic stimuli generated by the operation of the airguns, which 
introduce sound into the marine environment, may have the potential to 
cause Level B harassment of marine mammals in the survey area. The 
effects of sounds from airgun operations might include one or more of 
the following: Tolerance, masking (of natural sounds including inter- 
and intra-specific calls), 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; Wright et al., 2007; Tyack, 2009). 
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 planned project would result 
in any cases of temporary or permanent hearing impairment, or any 
significant non-auditory physical or physiological effects. Based on 
the available data and studies described here, some behavioral 
disturbance is expected, but NMFS expects the disturbance to be 
localized and short-term. NMFS described the range of potential effects 
from the specified activity in the notice of the proposed IHA (79 FR 
35642, June 23, 2014). A more comprehensive review of these issues can 
be found in the NSF/USGS PEIS (2011), USGS's ``Environmental Assessment 
for Seismic Reflection Scientific Research Surveys during 2014 and 2014 
in Support of Mapping the U.S. Atlantic Seaboard Extended Continental 
Margin and Investigating Tsunami Hazards'' and L-DEO's ``Draft 
Environmental Assessment of a Marine Geophysical Survey by the R/V 
Marcus G. Langseth in the Atlantic Ocean off Cape Hatteras, September 
to October 2014.''
    The notice of the proposed IHA (79 FR 35642, June 23, 2014) 
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 IHA 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

    NMFS included a detailed discussion of the potential effects of 
this action on marine mammal habitat, including physiological and 
behavioral effects on marine fish and invertebrates in the notice of 
the proposed IHA (79 FR 35642, June 23, 2014). The seismic survey will 
not result in any permanent impacts on habitats used by the marine 
mammals in the study 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

[[Page 52152]]

considered in further detail in the notice of the proposed IHA (79 FR 
35642, June 23, 2014). The main impact associated with the activity 
will be temporarily elevated noise levels and the associated direct 
effects on marine mammals.

Mitigation

    In order to issue an Incidental Take Authorization (ITA) under 
section 101(a)(5)(D) of the MMPA, NMFS must set forth the permissible 
methods of taking pursuant to such activity, and other means of 
effecting the least practicable impact on such marine mammal species or 
stock and its habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance, and the availability of 
such species or stock for taking for certain subsistence uses (where 
relevant). NMFS's duty under this ``least practicable impact'' standard 
is to prescribe mitigation reasonably designed to minimize, to the 
extent practicable, any adverse population level impacts, as well as 
habitat impacts. While population-level impacts can be minimized only 
by reducing impacts on individual marine mammals, not all takes 
translate to population-level impacts. NMFS's objective under the 
``least practicable impact'' standard is to design mitigation targeting 
those impacts on individual marine mammals that are most likely to lead 
to adverse population-level effects.
    USGS has reviewed the following source documents and has 
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 NSF/USGS PEIS;
    (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 planned activities, USGS and/or its designees shall 
implement the following mitigation measures for marine mammals:
    (1) Planning Phase;
    (2) Exclusion zones around the airgun(s);
    (3) Power-down procedures;
    (4) Shut-down procedures;
    (5) Ramp-up procedures; and
    (6) Special procedures for situations or species of concern.
    Planning Phase--Mitigation of potential impacts from the planned 
activities began during the planning phases of the planned activities. 
USGS considered whether the research objectives could be met with a 
smaller source than the full, 36-airgun array (6,600 in\3\) used on the 
Langseth, and determined that the standard 36-airgun array with a total 
volume of approximately 6,600 in\3\ was appropriate. USGS also worked 
with L-DEO and NSF to identify potential time periods to carry out the 
survey taking into consideration key factors such as environmental 
conditions (i.e., the seasonal presence of marine mammals and other 
protected species), weather conditions, equipment, and optimal timing 
for other seismic surveys using the Langseth. Most marine mammal 
species are expected to occur in the study area year-round, so altering 
the timing of the planned project from spring and summer months likely 
would result in no net benefits for those species.
    Exclusion Zones--USGS use radii to designate exclusion and buffer 
zones and to estimate take for marine mammals. Table 4 (see below) 
shows the distances at which one would expect marine mammal exposures 
to received sound levels (160 and 180/190 dB) from the 36 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.

Table 4--Measured (Array) or Predicted (Single Airgun) Distances To Which Sound Levels >=190, 180, and 160 dB re
1 [mu]Pa (rms) Could Be Received in Deep Water During the Seismic Survey in the Northwest Atlantic Ocean Off the
                       Eastern Seaboard, August to September 2014 and April to August 2015
----------------------------------------------------------------------------------------------------------------
                                                                       Predicted RMS radii distances (m)
   Sound source and volume      Tow depth (m)    Water depth  --------------------------------------------------
                                                     (m)            190 dB           180 dB           160 dB
----------------------------------------------------------------------------------------------------------------
Single Bolt airgun (40 in\3\)               9        >1,000 m  13 m (42.7 ft)   100 m (328.1     388 m (1,273
                                                                *100 m will be   ft).             ft)
                                                                used for
                                                                pinnipeds as
                                                                well as
                                                                cetaceans*.
36 airguns (6,600 in\3\).....               9        >1,000 m  286 m (938.3     927 m (3,041.3   5,780 m
                                                                ft).             ft).             (18,963.3 ft)
----------------------------------------------------------------------------------------------------------------

    PSVO's will be based aboard the seismic source vessel and would 
watch for marine mammals near the vessel during daytime airgun 
operations and during any ramp-ups of the airguns at night (see the 
``Vessel-Based Visual Monitoring'' section for a more detailed 
description of the PSVOs). If the PSVO detects marine mammal(s) within 
or about to enter the appropriate exclusion zone, the Langseth crew 
would immediately power-down the airgun array, or perform a shut-down 
if necessary (see ``Shut-down Procedures''). Table 4 (see above) 
summarizes the calculated distances at which sound levels (160, 180 and 
190 dB [rms]) are expected to be received from the 36 airgun array and 
the single airgun operating in deep water depths. Received sound levels 
have been calculated by USGS, in relation to distance and direction 
from the airguns, for the 36 airgun array and for the single 1900LL 40 
in\3\ airgun, which would be used during power-downs.
    Power-down Procedures--A power-down involves decreasing the number 
of airguns in use to one airgun, such that the radius of the 180 dB or 
190 dB zone is decreased to the extent that the observed marine 
mammal(s) are no longer in or about to enter the exclusion zone for the 
full airgun array. During a power-down for mitigation, USGS would 
operate one small airgun. The continued operation of one airgun is 
intended to (a) alert marine mammals to the presence of the seismic 
vessel in the area; and (b) retain the option of initiating a ramp-up 
to full operations under poor visibility conditions. In contrast, a 
shut-down occurs when all airgun activity is suspended.
    If the PSVO detects a marine mammal outside the exclusion zone that 
is likely to enter the exclusion zone, USGS will power-down the airguns 
to reduce the size of the 180 dB or 190 dB exclusion zone before the 
animal is within the exclusion zone. Likewise, if a mammal is already 
within the exclusion zone, when first detected USGS would power-down 
the airguns immediately. During a

[[Page 52153]]

power-down of the airgun array, USGS would operate the single 40 in\3\ 
airgun, which has a smaller exclusion zone. If the PSVO detects a 
marine mammal within or near the smaller exclusion zone around that 
single airgun (see Table 4), USGS will shut-down the airgun (see 
``Shut-Down Procedures'').
    Resuming Airgun Operations After a Power-down--Following a power-
down, the Langseth will not resume full airgun activity until the 
marine mammal has cleared the 180 or 190 dB exclusion zone (see Table 
4). The PSVO will consider the animal to have cleared the exclusion 
zone if:
     The PSVO has visually observed the animal leave the 
exclusion zone, or
     A PSVO has not sighted the animal within the exclusion 
zone for 15 minutes for species with shorter dive durations (i.e., 
small odontocetes or pinnipeds), or 30 minutes for species with longer 
dive durations (i.e., mysticetes and large odontocetes, including 
sperm, pygmy sperm, dwarf sperm, and beaked whales); or
     The vessel has transited outside the original 180 dB or 
190 dB exclusion zone after a 10 minute wait period.
    The Langseth crew will resume operating the airguns at full power 
after 15 minutes of sighting any species with short dive durations 
(i.e., small odontocetes or pinnipeds). Likewise, the crew will resume 
airgun operations at full power after 30 minutes of sighting any 
species with longer dive durations (i.e., mysticetes and large 
odontocetes, including sperm, pygmy sperm, dwarf sperm, and beaked 
whales).
    Because the vessel would have transited away from the vicinity of 
the original sighting during the 10 minute period, implementing ramp-up 
procedures for the full array after an extended power-down (i.e., 
transiting for an additional 35 minutes from the location of initial 
sighting) will not meaningfully increase the effectiveness of observing 
marine mammals approaching or entering the exclusion zone for the full 
source level and will not further minimize the potential for take. The 
Langseth's PSVOs will continually monitor the exclusion zone for the 
full source level while the mitigation airgun is firing. On average, 
PSVOs can observe to the horizon (10 km or 5.4 nmi) from the height of 
the Langseth's observation deck and should be able to state with a 
reasonable degree of confidence whether a marine mammal will be 
encountered within this distance before resuming airgun operations at 
full-power.
    Shut-down Procedures--USGS will shut-down the operating airgun(s) 
if a marine mammal is seen within or approaching the exclusion zone for 
the single airgun. USGS will implement a shut-down:
    (1) If an animal enters the exclusion zone of the single airgun 
after USGS has initiated a power-down; or
    (2) If an animal is initially seen within the exclusion zone of the 
single airgun when more than one airgun (typically the full airgun 
array) is operating (and it is not practical or adequate to reduce 
exposure to less than 180 dB [rms] or 190 dB [rms]).
    Considering the conservation status for the North Atlantic right 
whale, the airguns will be shut-down immediately in the unlikely event 
that this species is observed, regardless of the distance from the 
Langseth. Ramp-up will only begin if the North Atlantic right whale has 
not been seen for 30 minutes.
    Resuming Airgun Operations After a Shut-down--Following a shut-down 
in excess of 10 minutes, the Langseth crew would initiate a ramp-up 
with the smallest airgun in the array (40 in\3\). The crew will turn on 
additional airguns in a sequence such that the source level of the 
array would increase in steps not exceeding 6 dB per five-minute period 
over a total duration of approximately 30 minutes. During ramp-up, the 
PSVOs will monitor the exclusion zone, and if they sight a marine 
mammal, the Langseth crew will implement a power-down or shut-down as 
though the full airgun array were operational.
    During periods of active seismic operations, there are occasions 
when the Langseth crew will need to temporarily shut-down the airguns 
due to equipment failure or for maintenance. In this case, if the 
airguns are inactive longer than eight minutes, the crew will follow 
ramp-up procedures for a shut-down described earlier and the PSVOs will 
monitor the full exclusion zone and will implement a power-down or 
shut-down if necessary.
    If the full exclusion zone is not visible to the PSVO for at least 
30 minutes prior to the start of operations in either daylight or 
nighttime, the Langseth crew will not commence ramp-up unless at least 
one airgun (40 in\3\ or similar) has been operating during the 
interruption of seismic survey operations. Given these provisions, it 
is likely that the vessel's crew will not ramp-up the airgun array from 
a complete shut-down at night or during poor visibility conditions 
(i.e., in thick fog), because the outer part of the zone for that array 
will not be visible during those conditions.
    If one airgun has operated during a power-down period, 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. The vessel's crew will not initiate ramp-up of the airguns if a 
marine mammal is sighted within or near the applicable exclusion zones.
    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 and thus avoid any potential injury or 
impairment of their hearing abilities. USGS will follow a ramp-up 
procedure when the airgun array begins operating after a 10 minute 
period without airgun operations or when a power-down or shut-down has 
exceeded that period. USGS and L-DEO have used similar periods 
(approximately 8 to 10 minutes) during previous USGS and L-DEO seismic 
surveys.
    Ramp-up will begin with the smallest airgun in the array (40 
in\3\). Airguns will be added in a sequence such that the source level 
of the array would increase in steps not exceeding six dB per five 
minute period over a total duration of approximately 30 to 35 minutes 
(i.e., the time it takes to achieve full operation of the airgun 
array). During ramp-up, the PSVOs will monitor the exclusion zone, and 
if marine mammals are sighted, USGS will implement a power-down or 
shut-down as though the full airgun array 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 unless at least one 
airgun (40 in\3\ or similar) has been operating during the interruption 
of seismic survey operations. Given these provisions, it is likely that 
the airgun array will not be ramped-up from a complete shut-down at 
night or during poor visibility conditions (i.e., 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 during a 
power-down period, 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. USGS will not initiate a ramp-up of the 
airguns if a marine mammal is sighted within or near the applicable 
exclusion zones.

[[Page 52154]]

Use of a Small-Volume Airgun During Turns and Maintenance

    For short-duration equipment maintenance activities, USGS will 
employ the use of a small-volume airgun (i.e., 40 in\3\ ``mitigation 
airgun'') to deter marine mammals from being within the immediate area 
of the seismic operations. The mitigation airgun will be operated at 
approximately one shot per minute and will not be operated for longer 
than three hours in duration. The seismic survey's tracklines are 
continuous around turns and no mitigation airgun would be necessary. 
For longer-duration equipment maintenance or repair activities (greater 
than three hours), USGS will shut-down the seismic equipment and not 
involve using the mitigation airgun.
    During brief transits (e.g., less than three hours), one mitigation 
airgun will continue operating. The ramp-up procedure will still be 
followed when increasing the source levels from one airgun to the full 
airgun array. However, keeping one airgun firing will avoid the 
prohibition of a ``cold start'' during darkness or other periods of 
poor visibility. Through use of this approach, seismic operations may 
resume without the 30 minute observation period of the full exclusion 
zone required for a ``cold start,'' and without ramp-up if operating 
with the mitigation airgun for under 10 minutes, or with ramp-up if 
operating with the mitigation airgun over 10 minutes. PSOs will be on 
duty whenever the airguns are firing during daylight, during the 30 
minute periods prior to ramp-ups.
    Special Procedures for Situations or Species of Concern--It is 
unlikely that a North Atlantic right whale will be encountered during 
the seismic survey, but if so, the airguns will be shut-down 
immediately if one is visually sighted at any distance from the vessel 
because of its rarity and conservation status. The airgun array shall 
not resume firing (with ramp-up) until 30 minutes after the last 
documented North Atlantic right whale visual sighting. Concentrations 
of humpback, sei, fin, blue, and/or sperm whales will be avoided if 
possible (i.e., exposing concentrations of animals to 160 dB), and the 
array will be powered-down if necessary. For purposes of this planned 
survey, a concentration or group of whales will consist of six or more 
individuals visually sighted that do not appear to be traveling (e.g., 
feeding, socializing, etc.).

Mitigation Conclusions

    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 
impact on the affected marine mammal species or 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 
including consideration of personnel safety, practicality of 
implementation, and impact on the effectiveness of the activity.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    (1) Avoidance or minimization of injury or death of marine mammal 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    (2) A reduction in the numbers of marine mammals (total number of 
number at biologically important time or location) exposed to received 
levels of airgun operations, or other activities expected to result in 
the take of marine mammals (this goal may contribute to 1, above, or to 
reducing harassment takes only).
    (3) A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of airgun operations, or other activities expected 
to result in the take of marine mammals (this goal may contribute to 1, 
above, or to reducing harassment takes only).
    (4) A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of airgun operations, or other activities expected to result in 
the take of marine mammals (this goal may contribute to a, above, or to 
reducing the severity of harassment takes only).
    (5) Avoidance of minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    (6) For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on NMFS's evaluation of the applicant's measures, as well as 
other measures considered by NMFS or recommended by the public, NMFS 
has determined that the required mitigation measures provide the means 
of effecting the least practicable impact on marine mammal species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Monitoring and Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for ITAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that would result in increased knowledge of 
the species and of the level of taking or impacts on populations of 
marine mammals that are expected to be present in the action area. USGS 
submitted a marine mammal monitoring plan as part of the IHA 
application. It can be found in Section 13 of the IHA application. The 
plan may be modified or supplemented based on comments or new 
information received from the public during the public comment period.
    Monitoring measures prescribed by NMFS should accomplish one or 
more of the following general goals:
    (1) An increase in the probability of detecting marine mammals, 
both within the mitigation zone (thus allowing for more effective 
implementation of the mitigation) and in general to generate more data 
to contribute to the analyses mentioned below;
    (2) An increase in our understanding of how many marine mammals are 
likely to be exposed to levels of seismic airguns that we associate 
with specific adverse effects, such as behavioral harassment, TTS or 
PTS;
    (3) An increase in our understanding of how marine mammals respond 
to stimuli expected to result in take and how anticipated adverse 
effects on individuals (in different ways and to varying degrees) may 
impact the

[[Page 52155]]

population, species, or stock (specifically through effects on annual 
rates of recruitment or survival) through any of the following methods:
     Behavioral observations in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);
     Physiological measurements in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict receive level, distance from the source, and other 
pertinent information);
     Distribution and/or abundance comparisons in times or 
areas with concentrated stimuli versus times or areas without stimuli;
    (4) An increased knowledge of the affected species; and
    (5) An increase in our understanding of the effectiveness of 
certain mitigation and monitoring measures.

Monitoring

    USGS will conduct marine mammal monitoring during the seismic 
survey, 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. 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 region. USGS 
is prepared to discuss coordination of its 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 PSVOs 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. PSVOs 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 10 minutes for this cruise). 
When feasible, PSVOs will conduct observations during daytime periods 
when the seismic system is not operating (such as during transits) for 
comparison of sighting rates and behavior with and without airgun 
operations and between acquisition periods. Based on PSVO observations, 
the airguns will be powered-down or shut-down when marine mammals are 
observed within or about to enter a designated exclusion zone.
    During seismic operations in the northwest Atlantic Ocean off the 
Eastern Seaboard, at least five PSOs (four PSVOs and one Protected 
Species Acoustic Observer [PSAO]) will be based aboard the Langseth. 
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, two PSVOs will 
be on duty from the observation tower (i.e., the best available vantage 
point on the source vessel) to monitor marine mammals near the seismic 
vessel. Use of two simultaneous PSVOs will increase the effectiveness 
of detecting animals near the source vessel. However, during meal times 
and bathroom breaks, it is sometimes difficult to have two PSVOs on 
effort, but at least one PSVO will be on duty. PSVO(s) will be on duty 
in shifts no longer than 4 hours in duration.
    Two PSVOs will be on visual watch during all daytime ramp-ups of 
the seismic airguns. A third PSAO will monitor the PAM equipment 24 
hours a day to detect vocalizing marine mammals present in the action 
area. In summary, a typical daytime cruise will have scheduled two 
PSVOs on duty from the observation tower, and a third PSAO on PAM. 
Other ship's 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 Langseth is a suitable platform for marine mammal observations. 
When stationed on the observation platform, the eye level will be 
approximately 21.5 m (70.5 ft) above sea level, and the PSVOs will have 
a good view around the entire vessel. During daytime, the PSVO(s) will 
scan the area around the vessel systematically with reticle binoculars 
(e.g., 7 x 50 Fujinon), Big-eye binoculars (25 x 150), and with the 
naked eye. During darkness or low-light conditions, night vision 
devices (monoculars) and a forward looking infrared (FLIR) camera will 
be available, when required. Laser range-finding binoculars (Leica LRF 
1200 laser rangefinder or equivalent) will be available to assist with 
distance estimation. Those are useful in training observers to estimate 
distances visually, but are generally not useful in measuring distances 
to animals directly; that is done primarily with the reticles in the 
binoculars.
    When marine mammals are detected within or about to enter the 
designated exclusion zone, the airguns will immediately be powered-down 
or shut-down if necessary. The PSVO(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 
and pinnipeds) or 30 minutes for species with longer dive durations 
(mysticetes and large odontocetes, including sperm, pygmy sperm, dwarf 
sperm, killer, and beaked whales).

Vessel-Based Passive Acoustic Monitoring

    Vessel-based, towed PAM will complement the visual monitoring 
program, when practicable. Visual monitoring typically is not effective 
during periods of poor visibility or at night, and even with good 
visibility, is unable to detect marine mammals when they are below the 
surface or beyond visual range. PAM can be used in addition to visual 
observations to improve detection, identification, and localization of 
cetaceans. The PAM system will serve to alert visual observers (if on 
duty) when vocalizing cetaceans are detected. It is only useful when 
marine mammals call, but it does not depend on good visibility. It will 
be monitored in real-time so that the PSVOs can be advised when 
cetaceans are acoustically detected.
    The PAM system consists of both hardware (i.e., hydrophones) and 
software (i.e., Pamguard). The ``wet end'' of the system consists of a 
towed hydrophone array that is connected to the vessel by a tow cable. 
The tow cable is 250 m (820.2 ft) long, and the hydrophones are fitted 
in the last 10 m (32.8 ft) of cable. A depth gauge is attached to the 
free end of the cable, and the cable is typically towed at depths 20 m 
(65.6 ft) or less. The array would be deployed from a winch located on 
the back deck. A deck cable will connect from the winch to the main 
computer laboratory where the acoustic station, signal conditioning, 
and processing system would be located. The acoustic signals received 
by the hydrophones are amplified, digitized, and then processed by the 
Pamguard software. The PAM system, which has a configuration of 4 
hydrophones, can detect a frequency bandwidth of 10 Hz to 200 kHz.
    One PSAO, an expert bioacoustician (in addition to the four PSVOs) 
with primary responsibility for PAM, would

[[Page 52156]]

be onboard the Langseth. The expert bioacoustician will design and set 
up the PAM system and be present to operate, oversee, and troubleshoot 
any technical problems with the PAM system during the planned survey. 
The towed hydrophones will ideally be monitored by a PSO 24 hours per 
day while within the seismic survey area during airgun operations, and 
during most periods when the Langseth is underway while the airguns are 
not operating. PSOs will take turns rotating on visual watch and on the 
PAM system. However, PAM may not be possible if damage occurs to the 
array or back-up systems during operations. The primary PAM streamer on 
the Langseth is a digital hydrophone streamer. Should the digital 
streamer fail, back-up systems should include an analog spare streamer 
and a hull-mounted hydrophone. One PSO will monitor the acoustic 
detection system by listening to the signals from two channels via 
headphones and/or speakers and watching the real-time spectrographic 
display for frequency ranges produced by cetaceans. The PSAO monitoring 
the acoustical data would be on shift for no greater than six hours at 
a time. All PSOs are expected to rotate through the PAM position, 
although the expert PSAO (most experienced) will be on PAM duty more 
frequently.
    When a vocalization is detected while visual observations (during 
daylight) are in progress, the PSAO will contact the PSVO immediately, 
to alert him/her to the presence of cetaceans (if they have not already 
been seen), and to allow a power-down or shut-down to be initiated, if 
required. When bearings (primary and mirror-image) to calling 
cetacean(s) are determined, the bearings would be relayed to the 
PSVO(s) to help him/her sight the calling animal. During non-daylight 
hours, when a cetacean is detected by acoustic monitoring and may be 
close to the source vessel, the Langseth crew will be notified 
immediately so that the proper mitigation measure may be implemented.
    The information regarding the call will be entered into a database. 
Data entry will include an acoustic encounter identification number, 
whether it was linked with a visual sighting, date, time when first and 
last heard and whenever any additional information was recorded, 
position and water depth when first detected, bearing if determinable, 
species or species group (e.g., unidentified dolphin, sperm whale), 
types and nature of sounds heard (e.g., clicks, continuous, sporadic, 
whistles, creaks, burst pulses, strength of signal, etc.), and any 
other notable information. The acoustic detection can also be recorded 
for further analysis.

PSO Data and Documentation

    PSVOs 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 would be used to estimate 
numbers of animals potentially `taken' by harassment. They will also 
provide information needed to order a power-down or shut-down of the 
airguns when a marine mammal is within or near the appropriate 
exclusion zone. Observations will also be made during daytime periods 
when the Langseth is underway without seismic operations. There will 
also be opportunities to collect baseline biological data during the 
transits to, from, and through the study area.
    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 airguns or vessel (e.g., none, avoidance, 
approach, paralleling, etc.), and behavioral pace.
    2. Time, location, heading, speed, activity of the vessel, Beaufort 
sea state and 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 and ramp-ups, power-downs, or shut-downs will be 
recorded in a standardized format. The PSVOs will record this 
information onto datasheets. During periods between watches and periods 
when operations are suspended, those data will be entered into a laptop 
computer running a custom electronic database. The accuracy of the data 
entry will be verified by computerized data validity checks as the data 
are entered and by subsequent manual checking of the database. These 
procedures will allow initial summaries of data to be prepared during 
and shortly after the field program, and will facilitate transfer of 
the data to statistical, graphical, and other programs for further 
processing and archiving.
    Results from the vessel-based observations will provide:
    1. The basis for real-time mitigation (airgun power-down or shut-
down).
    2. Information needed to estimate the number of marine mammals 
potentially taken by harassment, which must be reported to NMFS.
    3. Data on the occurrence, distribution, and activities of marine 
mammals in the area where the seismic study is conducted.
    4. Information to compare the distance and distribution of marine 
mammals relative to the source vessel at times with and without seismic 
activity.
    5. Data on the behavior and movement patterns of marine mammals 
seen at times with and without seismic activity.

Reporting

    USGS will submit a comprehensive report to NMFS and NSF within 90 
days after the end of phase 1 in 2014 and another comprehensive report 
to NMFS and NSF within 90 days after the end of phase 2 in 2015 for the 
cruise. The report will describe the operations that were conducted and 
sightings of marine mammals within the vicinity of the operations. The 
report 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, associated 
seismic survey activities, and associated PAM detections). The report 
will minimally include:
     Summaries of monitoring effort--total hours, total 
distances, and distribution of marine mammals through the study period 
accounting for Beaufort sea state and wind force, and other factors 
affecting visibility and detectability of marine mammals;
     Analyses of the effects of various factors influencing 
detectability of marine mammals including Beaufort sea state and wind 
force, 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.

[[Page 52157]]

    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, USGS, and NSF Web sites at: 
https://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha, https://
woodshole.er.usgs.gov/project-pages/environmentalcompliance/
index.html, and https://www.nsf.gov/geo/oce/encomp/index.jsp.
    Reporting Prohibited Take--In the unanticipated event that the 
specified activity clearly causes the take of a marine mammal in a 
manner not permitted by the authorization (if issued), such as an 
injury, serious injury, or mortality (e.g., ship-strike, gear 
interaction, and/or entanglement), the USGS shall immediately cease the 
specified activities and immediately report the incident to the 
Incidental Take Program Supervisor, Permits and Conservation Division, 
Office of Protected Resources, NMFS, at 301-427-8401 and/or by email to 
Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov, the NMFS Greater 
Atlantic Region Marine Mammal Stranding Network at 866-755-6622 
(Mendy.Garron@noaa.gov), and the NMFS Southeast Region Marine Mammal 
Stranding Network at 877-433-8299 (Blair.Mase@noaa.gov and 
Erin.Fougeres@noaa.gov). The report must include the following 
information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source used 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 animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    USGS shall not resume its activities 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. The USGS may not resume 
their activities until notified by NMFS via letter, email, or 
telephone.
    Reporting an Injured or Dead Marine Mammal with an Unknown Cause of 
Death--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 NMFS describes in the next 
paragraph), the USGS would immediately report the incident to the 
Incidental Take Program Supervisor, Permits and Conservation Division, 
Office of Protected Resources, at 301-427-8401 and/or by email to 
Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov, the NMFS Greater 
Atlantic Region Marine Mammal Stranding Network (866-755-6622) and/or 
by email to the Greater Atlantic Regional Stranding Coordinator 
(Mendy.Garron@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 this section. Activities may continue while NMFS reviews the 
circumstances of the incident. NMFS will work with the USGS to 
determine whether modifications in the activities are appropriate.
    Reporting an Injured or Dead Marine Mammal Not Related to the 
Activities--In the event that 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 authorized activities (e.g., 
previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), the USGS will report the incident 
to the Incidental Take Program Supervisor, Permits and Conservation 
Division, Office or Protected Resources, at 301-427-8401 and/or by 
email to Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov, the 
NMFS Greater Atlantic Region Marine Mammal Stranding Network (866-755-
6622), and/or by email to the Greater Atlantic Regional Stranding 
Coordinator (Mendy.Garron@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), within 24 hours of the discovery. The 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].

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


[[Page 52158]]

    Level B harassment is anticipated and authorized as a result of the 
marine seismic survey in the northwest Atlantic Ocean off the Eastern 
Seaboard. 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 and NMFS's estimates 
of the numbers of marine mammals that could be affected during the 
seismic project in the northwest Atlantic Ocean. The estimates are 
based on a consideration of the number of marine mammals that could be 
harassed by seismic operations with the 36 airgun array to be used. The 
length of the planned 2D seismic survey area in 2014 is approximately 
3,165 km (1,704 nmi) and in 2015 is approximately 3,115 km (1,682 nmi) 
in the U.S. ECS region of the Eastern Seaboard in the Atlantic Ocean, 
as depicted in Figure 1 of the IHA application. For estimating take and 
other calculations, the 2015 tracklines are assumed to be identical in 
length to the 2014 tracklines (even though they are slightly shorter).
    NMFS and USGS assumes that, during simultaneous operations of the 
airgun array and the other sources, any marine mammals close enough to 
be affected by the multi-beam echosounder and sub-bottom profiler will 
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 multi-beam echosounder and sub-bottom profiler given 
their characteristics (e.g., narrow, downward-directed beam) and other 
considerations described previously in the notice of the proposed IHA 
(79 FR 35642, June 23, 2014). Such reactions are not considered to 
constitute ``taking'' (NMFS, 2001). Therefore, NMFS and USGS provided 
no additional allowance for animals that could be affected by sound 
sources other than airguns and NMFS has not authorized take from these 
other sound sources.
    Density estimates for marine mammals within the vicinity of the 
planned study area are limited. Density data for species found along 
the East Coast of the U.S. generally extend slightly outside of the 
U.S. EEZ. The study area, however, is well beyond the U.S. EEZ, and is 
well off the continental shelf break. The planned survey lines for the 
2014 survey are located in the far eastern portion of the study area, 
primarily within the area where little to no density data are currently 
available. It was determined that the best available information for 
density data (for those species where density data existed) of species 
located off the U.S. East Coast was housed at the Strategic 
Environmental and Development Program (SERDP)/National Aeronautics and 
Space Administration (NASA)/NOAA Marine Animal Model Mapper and OBIS-
SEAMAP database. Within this database, the model outputs for all four 
seasons from the U.S. Department of the Navy Operating Area (OPAREA) 
Density Estimates (NODE) for the Northeast OPAREA and Southeast OPAREA 
(Department of the Navy 2007a, 2007b) were used to determine the mean 
density (animals per square kilometer) for 19 of the 34 marine mammals 
with the potential to occur in the study area. Those species include 
fin, minke, Atlantic spotted, bottlenose, long-finned and short-finned 
pilot, pantropical spotted, Risso's, short-beaked common, striped, 
sperm, rough-toothed, dwarf and pygmy sperm, Sowerby's, Blainville's, 
Gervais', True's, and Cuvier's beaked whales. Within the NODE document, 
the density calculations and models both took into account detection 
probability ([fnof][0]) and availability (g[0]) biases. Model outputs 
for each season are available in the database. The data from the NODE 
summer density models, which include the months of June, July, and 
August, were used as the 2014 survey is planned to take place between 
late August and early September. Of the seasonal NODE density models 
available, it is expected that the summer models are the most accurate 
and robust as the survey data used to create all of the models were 
obtained during summer months. The models for the winter, spring, and 
fall are derived from the data collected during the summer surveys, and 
therefore are expected to be less representative of actual species 
density during those seasons.
    For species for which densities were unavailable as described 
above, but for which there were Ocean Biogeographic Information System 
(OBIS) sightings within or adjacent to the planned study area, NMFS has 
included an authorized take for the mean group size for the species. 
Generally, to quantify this coverage, NMFS assumed that USGS could 
potentially encounter one group of each species during each of the 
seismic survey legs (recognizing that interannual variation and the 
potential presence of ephemeral features could drive differing 
encounter possibilities in the two legs), and NMFS thinks it is 
reasonable to use the average (mean) groups size (weighted by effort 
and rounded up) to estimate the take from these potential encounters. 
The mean group size were determined based on data reported from the 
Cetacean and Turtle Assessment Program (CeTAP) surveys (CeTAP, 1982) 
and the Atlantic Marine Assessment Program for Protected Species 
(AMAPPS) surveys in 2010, 2011, 2012, and 2013. Because we believe it 
is unlikely, we do not think it is necessary to assume that the largest 
group size will be encountered. PSOs based on the vessel 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 would be used to estimate numbers of animals 
potentially ``taken'' by harassment. If the estimated numbers of 
animals potentially ``taken'' by harassment approach or exceed the 
number of authorized takes, USGS will have to re-initiate consultation 
with NMFS under the MMPA and/or ESA.
    The estimated numbers of individuals potentially exposed to sound 
during the planned 2014 to 2015 survey are presented below and are 
based on the 160 dB (rms) criterion currently used for all cetaceans 
and pinnipeds. It is assumed that marine mammals exposed to airgun 
sounds that strong could change their behavior sufficiently to be 
considered ``taken by harassment.'' Table 6 shows the density estimates 
calculated as described above and the estimates of the number of 
different individual marine mammals that potentially could be exposed 
to greater than or equal to 160 dB (rms) during the seismic survey if 
no animals moved away from the survey vessel. The authorized take is 
given in the middle (fourth from the left) column of Table 6.
    With respect to the take authorized for North Atlantic right 
whales, NMFS's Office of Protected Resources, Permits and Conservation 
Division, formally consulted 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. NMFS's Office of Protected 
Resources, Endangered Species Act Interagency Cooperation Division 
issued a Biological Opinion and ITS that included 3 takes of North 
Atlantic right

[[Page 52159]]

whales. To comply with the ITS, NMFS's Office of Protected Resources, 
Permits and Conservation Division has also authorized 3 takes of North 
Atlantic right whales incidental to USGS's seismic survey.
    It should be noted that unlike previous USGS, NSF, and L-DEO 
seismic surveys aboard the Langseth, the planned survey would be 
conducted as almost one continuous line. Therefore, the ensonified area 
for the seismic survey does not include a contingency factor (typically 
increased 25% to accommodate turns, lines that may need to be repeated, 
equipment testing, etc.) in line-kilometers. As 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. Also, any marine mammal 
sightings within or near the designated exclusion zones will result in 
a power-down and/or shut-down of seismic operations as a mitigation 
measure. Thus, the following estimates of the numbers of marine mammals 
potentially exposed to 160 dB (rms) sounds 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.
    The number of different individuals that could be exposed to airgun 
sounds with received levels greater than or equal to 160 dB (rms) on 
one or more occasions can be estimated by considering the total marine 
area that will 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 will be within the 160 dB 
radius around the operating airguns. In many seismic surveys, this 
total marine area includes overlap, as seismic surveys are often 
conducted in parallel survey lines where the ensonified areas of each 
survey line would overlap. The planned tracklines in 2014 and 2015 will 
not have overlap as the individual line segments do not run parallel to 
each other. The entire survey could be considered one continual survey 
line with slight turns (no more than 120 degrees) between each line 
segment. During the planned seismic survey, the vessel would continue 
on the extensive survey line path, not staying within a smaller defined 
area as most seismic surveys often do. The numbers of different 
individuals potentially exposed to greater than or equal to 160 dB 
(rms) were calculated by multiplying the expected species density (for 
those marine mammal species that had density data available) times the 
total anticipated area to be ensonified to that level during airgun 
operations (3,165 km of survey lines). The total area expected to be 
ensonified was determined by multiplying the total trackline distance 
(3,165 km times the width of the swath of the 160 dB buffer zone (2 
times 5.78 km). Using this approach, a total of 36,600 km\2\ (10,671 
nmi\2\) will fall within the 160 dB isopleth throughout the planned 
survey in 2014. The planned survey in 2015 is expected to ensonify an 
almost identical area (to within 2%); therefore, the same ensonified 
area of 36,600 km\2\ (10,671 nmi\2\) was used for calculation purposes 
since the number of estimated takes would be very similar for each of 
the two years. The number of estimated takes for the planned survey in 
2015 may need to be seasonally adjusted if the activity takes place in 
the late spring or early summer. Because it is uncertain at this time 
whether the 2015 survey will be scheduled in the spring (April and May) 
or summer (June, July, and August) months, estimated takes were 
calculated for both seasons. For purposes of conservatively estimating 
the number of takes, the higher density (for spring or summer) was used 
for each species since it is not known at this time which season the 
2015 planned survey will take place in the April to August 2015 
timeframe. If the 2015 survey occurred in the spring rather than 
summer, the density data suggests that takes will likely be higher for 
only the humpback whale, beaked whales, and bottlenose dolphin, and 
takes will likely be fewer for nine species (i.e., sperm whale, short-
finned and long-finned pilot whales, Atlantic spotted, pantropical 
spotted, striped, Clymene, short-beaked common, and Risso's dolphin), 
and unchanged for the remaining species.

 Table 6--Estimated Densities of Marine Mammal Species and Estimates of Numbers of Marine Mammals Exposed to Sound Levels >=160 dB During USGS's Seismic
                   Survey in the Northwest Atlantic Ocean Off the Eastern Seaboard, August to September 2014 and April to August 2015
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                      Approximate
                                                                                                                     percentage of
                                                       Calculated take                                                estimated of
                                                        authorization                                                   regional
                                    Density spring/    2014/2015 [i.e.,  Authorized take for                        population/stock
                                   summer (/  estimated number  2014/2015 (includes  Abundance (regional   2014 to 2015 for   Population trend
             Species                km\2\) \1\ *mean    of individuals   increase to average   population/stock)    authorized take           \6\
                                      group size*      exposed to sound    group size) \3\            \4\           (stock pro-rated
                                                       levels >=160 dB                                              for 80% outside
                                                       re 1 [mu]Pa] \2\                                             EEZ in 2014 and
                                                                                                                    90% outside U.S.
                                                                                                                    EEZ in 2015) \5\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
    North Atlantic right whale...             NA *3*                0/0  3 + 3 = 6 *MMPA      455/455............   0.66/0.66 (0.44)  Increasing.
                                                                          Proposed IHA* (1
                                                                          or 2) + (1 or 2) =
                                                                          3 *Authorized to
                                                                          Comply with ESA
                                                                          ITS*.
    Humpback whale...............    0.0010170/0 *3*               0/38  3 + 38 = 41........  11,600/823.........   0.35/4.98 (0.61)  Increasing.
    Minke whale..................         0.0000350/                2/2  2 + 2 = 4..........  138,000/20,741.....      0.0014/0.0096  NA.
                                           0.0000360                                                                         (<0.01)
    Bryde's whale................             NA *3*                0/0  3 + 3 = 6..........  NA/NA..............         NA/NA (NA)  NA.
    Sei whale....................             NA *3*                0/0  3 + 3 = 6..........  10,300/357.........   0.06/1.68 (0.56)  NA.
    Fin whale....................  0.000060/0.000061                3/3  3 + 3 = 6..........  26,500/3,522.......   0.02/0.17 (0.06)  NA.
    Blue whale...................             NA *1*                0/0  1 + 1 = 2..........  855/NA (440           0.23/0.45 (0.45)  NA.
                                                                                               minimum).
Odontocetes:
    Sperm whale..................         0.0019050/              83/83  83 + 83 = 166......  13,190/2,288.......   1.26/7.26 (1.14)  NA.
                                           0.0022510

[[Page 52160]]

 
    Pygmy sperm whale............         0.0008850/              33/33  33 + 33 = 66.......  NA/3,785...........     NA/1.74 (0.29)  NA.
                                            0.008970
    Dwarf sperm whale............         0.0008850/              33/33  33 + 33 = 66.......  NA/3,785...........     NA/1.74 (0.29)  NA.
                                           0.0008970
    Northern bottlenose whale....             NA *2*                0/0  2 + 2 = 4..........  40,000/NA..........       0.01/NA (NA)  NA.
    Cuvier's beaked whale........         0.0021370/              84/84  84 + 84 = 168......  NA/6,532...........      NA/1.29 (0.4)  NA.
                                           0.0022870
    Mesoplodon spp. (i.e.,         .................  .................  ...................  NA/7,092...........     NA/2.37 (0.37)  NA.
     True's, Gervais', Sowerby's,
     and Blainville's beaked
     whale.
    Bottlenose dolphin...........         0.0069560/            244/255  244 + 255 = 499....  NA/77,532..........      NA/0.64 (0.1)  NA.
                                           0.0066470
    Atlantic white-sided dolphin.            NA *33*                0/0  33 + 33 = 66.......  10,000 to 100,000s/   0.66/0.14 (0.02)  NA.
                                                                                               48,819.
    Fraser's dolphin.............           NA *100*                0/0  100 + 100 = 200....  NA/NA..............         NA/NA (NA)  NA.
    Atlantic spotted dolphin.....         0.0285700/        1,056/1,056  1,056 + 1,056 =      NA/44,715..........     NA/4.72 (0.71)  NA.
                                           0.0288400                      2,112.
    Pantropical spotted dolphin..         0.0194900/            724/724  724 + 724 = 1,448..  NA/3,333...........    NA/43.44 (6.54)  NA.
                                           0.0197600
    Striped dolphin..............         0.1330000/        4,916/4,916  4,916 + 4,916 =      NA/54,807..........    NA/17.94 (2.69)  NA.
                                           0.1343000                      9,832.
    Spinner dolphin..............            NA *65*                0/0  65 + 65 = 130......  NA/NA..............         NA/NA (NA)  NA.
    Clymene dolphin..............   0.0093110/0 *52*              0/341  52 + 341 = 393.....  NA/NA..............         NA/NA (NA)  NA.
    Short-beaked common dolphin..         0.0053940/            203/203  203 + 203 = 406....  NA/173,486.........     NA/0.23 (0.04)  NA.
                                           0.0055320
    Rough-toothed dolphin........          0.004200/              16/16  16 + 16 = 32.......  NA/271.............    NA/11.81 (2.21)  NA.
                                           0.0004260
    Risso's dolphin..............         0.0092150/            342/342  342 + 342 = 684....  NA/18,250..........     NA/3.75 (0.57)  NA.
                                           0.0093180
    Melon-headed whale...........           NA *100*                0/0  100 + 100 = 200....  NA/NA..............         NA/NA (NA)  NA.
    Pygmy killer whale...........            NA *25*                0/0  25 + 25 = 50.......  NA/NA..............         NA/NA (NA)  NA.
    False killer whale...........            NA *15*                0/0  15 + 15 = 30.......  NA/NA..............         NA/NA (NA)  NA.
    Killer whale.................             NA *6*                0/0  6 + 6 = 12.........  NA/NA..............         NA/NA (NA)  NA.
    Short-finned pilot whale.....         0.0108000/            697/697  697 + 697 = 1,394..  780,000/21,515.....   0.18/6.48 (0.98)  NA.
                                           0.0190400
    Long-finned pilot whale......         0.0108000/            697/697  697 + 697 = 1,394..  780,000/26,535.....   0.18/5.25 (0.79)  NA.
                                           0.0190400
    Harbor porpoise..............             NA *4*                0/0  4 + 4 = 8..........  500,000/79,883.....         0.002/0.01  NA.
                                                                                                                             (<0.01)
Pinnipeds:
    Harbor seal..................                 NA                0/0  0 + 0 = 0..........  NA/70,142..........              NA/NA  NA.
    Gray seal....................                 NA                0/0  0 + 0 = 0..........  NA/NA (348,999                   NA/NA  Increasing.
                                                                                               minimum 2012).
    Harp seal....................                 NA                0/0  0 + 0 = 0..........  8.6 to 9.6 million/              NA/NA  NA.
                                                                                               NA (8.3 million in
                                                                                               2012).
    Hooded seal..................                 NA                0/0  0 + 0 = 0..........  600,000/NA (592,100              NA/NA  NA.
                                                                                               minimum in 2007).
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ OBIS-SERDP-Navy NODE 2007a and 2007b (for those species where density data is available).
\2\ Calculated take is estimated density multiplied by the 160 dB ensonified area.
\3\ Requested take authorization was increased to group size for species for which densities were not available but that have been sighted near the
  survey area (CeTAP, 1984).
\4\ Stock sizes are best populations from NMFS Stock Assessment Reports where available (see Table 3 in above).
\5\ Requested takes expressed as percentages of the larger regional population and NMFS Stock Assessment Reports, where available.
\6\ Based on NMFS Stock Assessment Reports.

Applying the approach described above, approximately 36,600 km\2\ will 
be within the 160 dB isopleth on one or more occasions during the 
planned survey in 2014. The planned survey in 2015 is expected to 
ensonify an almost identical area (to within 2%); therefore an 
ensonified area of 36,600 km\2\ was used for the planned surveys in 
2014 and 2015. Because this approach 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 
trackline as the Langseth approaches in

[[Page 52161]]

response to increasing sound levels before the levels reach 160 dB 
(rms). Another way of interpreting the estimates that follow is that 
they represent the number of individuals that are expected (in the 
absence of a seismic program) to occur in the waters that will be 
exposed to greater than or equal to 160 dB (rms).

Encouraging and Coordinating Research

    USGS will coordinate the planned marine mammal monitoring program 
associated with the seismic survey with other parties that may have 
interest in this area and specified activity. USGS will coordinate with 
applicable U.S. agencies (e.g., NMFS), and will comply with their 
requirements.

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

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

Analyses and Determinations

Negligible Impact

    Negligible impact is ``an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival'' (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes 
alone is not enough information on which to base an impact 
determination. In addition to considering estimates of the number of 
marine mammals that might be ``taken'' through behavioral harassment, 
NMFS must consider other factors, such as the likely nature of any 
responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A harassment takes, 
the number of estimated mortalities, and effects on habitat.
    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.
    As described above 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 availability of alternate areas of similar habitat value 
for marine mammals to temporarily vacate the survey area during the 
operation of the airgun(s) to avoid acoustic harassment;
    (3) The potential for temporary or permanent hearing impairment is 
relatively low and will likely be avoided through the implementation of 
the required monitoring and mitigation measures (including power-down 
and shut-down measures); and
    (4) The likelihood that marine mammal detection ability by trained 
PSOs is high at close proximity to the vessel.
    Table 6 of this document outlines the number of authorized Level B 
harassment takes that are anticipated as a result of these activities. 
The type of Level B (behavioral) harassment that could result from the 
action are described in the ``Potential Effects of the Specified 
Activity on Marine Mammals'' section above, and include tolerance, 
masking, behavioral disturbance, TTS, PTS, and non-auditory or 
physiological effects. Level B (behavioral harassment occurs at the 
level of the individual(s) and does not assume any resulting 
population-level consequences. For the 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). While seismic operations are anticipated to 
occur on consecutive days, the estimated duration of the survey will 
last no more than a total of 36 days (a 17 to 18 day leg in August to 
September 2014 and a 17 to 18 day leg in April to August 2015). 
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). The seismic surveys will not 
take place in areas of significance for marine mammal feeding, resting, 
breeding, or calving and will not adversely impact marine mammal 
habitat. Furthermore, the vessel will be constantly travelling over 
distances, and some animals may only be exposed to and harassed by 
sound for less than a day.
    NMFS's practice has been to apply the 160 dB re 1 [mu]Pa (rms) 
received level threshold for underwater impulse sound levels to 
determine whether take by Level B harassment occurs. 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 marine seismic survey in the northwest Atlantic Ocean off 
of the Eastern Seaboard, August to September 2014 and April to August 
2015, may result, at worst, in a modification in behavior and/or low-
level physiological effects (Level B harassment) of certain species of 
marine mammals. No injuries, serious injuries, or mortalities are 
anticipated to occur as a result of USGS's planned marine seismic 
survey, and none are authorized by NMFS.
    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

[[Page 52162]]

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. 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 and monitoring measures that 
will minimize impacts to marine mammals. NMFS has issued IHAs for 
marine mammal take for similar types of research seismic surveys for 
over 10 years and required similar mitigation and monitoring measures. 
In no case have the submitted monitoring reports suggested that marine 
mammal impacts have exceeded those anticipated in our analysis under 
the MMPA.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the required monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
USGS's marine seismic survey will have a negligible impact on the 
affected marine mammal species or stocks.

Small Numbers

    As mentioned previously, NMFS estimates that 34 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 or stocks that may be taken by Level B harassment 
are provided in Table 6 of this document. No takes of pinnipeds are 
expected due to a lack of species observations within the study area, 
the great distance offshore, and the deep water depths of the study 
area. It should be noted that the stock populations for each marine 
mammal species in the NMFS Stock Assessment Reports are generally for 
species populations in U.S. waters, which may underestimate actual 
population sizes for species that have ranges that will include waters 
outside the U.S. EEZ.
    NMFS makes it small numbers determination based on the number of 
marine mammals that would be taken relative to the populations of the 
affected species or stocks. NMFS's take estimates for the current 
survey are based on a consideration of the number of marine mammals 
that could be harassed by seismic operations with the entire seismic 
survey area, both within and outside of the U.S. EEZ. Given that the 
take estimates were calculated for the entire survey area, NMFS 
concludes that a portion of the authorized takes would take place 
within the U.S. EEZ and the remainder would take place outside of the 
U.S. EEZ. To make our small numbers determination for U.S. EEZ stocks, 
we therefore apportioned 10 to 20% of the authorized take to the U.S. 
EEZ, given that approximately 80% of the survey tracklines in 2014 and 
approximately 90% of the survey tracklines in 2015 are outside of the 
U.S. EEZ. See Table 6 for the small number calculations of the U.S. EEZ 
stock with abundance data based on this apportionment. All of the takes 
that NMFS expects to occur within the U.S. EEZ represent a small number 
relative the affected U.S. EEZ stocks.
    As described above, approximately 80% of the survey tracklines in 
2014 and approximately 90% of the survey tracklines in 2015 are within 
International Waters (i.e., the high seas) and are outside of the U.S. 
EEZ; therefore, the regional population is more applicable for NMFS's 
small numbers determinations, as most of the ensonified area and 
estimated takes are further than 200 nmi from the U.S. coastline. 
Regional abundance data exists for 12 species that could be affected by 
the survey. See Table 6 for the small number calculations of the 
species with regional abundance data. The take authorized for these 
species represents a small number relative to the affected regional 
populations.
    For the remaining species for which NMFS has U.S. EEZ stock 
abundance data but no regional abundance data, NMFS concludes that if 
the total authorized take represents a small number of the U.S. EEZ 
stock (also calculated in Table 6), it will also represent a small 
number of the greater regional population, based on the larger and 
wider ranging populations expected in the high seas. This conclusion is 
supported by the fact that, for the species with both regional and 
stock-specific abundance populations, the regional abundance is on the 
order of five to twenty times higher than the abundance of the stock. 
For the pantropical spotted dolphin, the total authorized take would 
represent more than 43% of the U.S. EEZ stock. However, as noted in 
Table 6, the take expected to occur in the U.S. EEZ represents 
approximately 6.5% of the affected U.S. EEZ stock. The remainder of the 
takes would occur outside the U.S EEZ. Although no regional abundance 
estimate exists for the pantropical spotted dolphin, it is one of the 
most abundant cetaceans on the globe and occurs in all tropical to warm 
temperate waters between 40[deg] N and S (Folkens 2002). Therefore, we 
are confident that the authorized take represents a small number 
compared to the greater regional Atlantic pantropical spotted dolphin 
population that occurs outside of the U.S. EEZ. No known current 
regional population or stock abundance estimates for the northwest 
Atlantic Ocean are available for the eight remaining species under 
NMFS's jurisdiction that could potentially be affected by Level B 
harassment over the course of the IHA. These species include the 
Bryde's whale, Fraser's, spinner, and Clymene dolphins, and the melon-
headed, pygmy killer, false killer, and killer whales. Bryde's whales 
are distributed worldwide in tropical and sub-tropical waters and their 
occurrence in the study area is rare. In the western North Atlantic 
Ocean, Bryde's whales are reported from off the southeastern U.S. and 
southern West Indies to Cabo Frio, Brazil (Leatherwood and Reeves, 
1983). Fraser's dolphins are distributed worldwide in tropical waters 
and their occurrence in the study area is rare. Spinner dolphins are 
found in all tropical and sub-tropical oceans and their occurrence in 
the study area is rare. Melon-headed whales are distributed worldwide 
in tropical to sub-tropical waters and their occurrence in the study 
area is rare. The pygmy killer whale is distributed worldwide in 
tropical to sub-tropical waters and their occurrence in the study area 
is rare. The false killer whale is distributed worldwide throughout 
warm temperate and tropical oceans and their occurrence in the study 
area is rare. Killer whales are characterized as uncommon or rare in 
waters of the U.S. Atlantic EEZ (Katona et al., 1988). Their 
distribution extends from the Arctic ice-edge to the West Indies, often 
in offshore and mid-ocean areas. There are estimated to be at least 
approximately 92,500 killer whales worldwide.
    The Clymene dolphin is endemic to tropical and sub-tropical waters 
of the Atlantic, including the Caribbean Sea and Gulf of Mexico 
(Jefferson and Curry, 2003; Jefferson et al., 2008). This species 
prefer warm waters and records extend from southern Brazil and Angola 
and north to Mauritania and New Jersey off the U.S. east coast 
(Jefferson et al., 2008). Their occurrence in the study area is rare. 
The abundance estimate for the Clymene dolphin in the western North 
Atlantic was 6,086 in 2003; this estimate is older than eight years and 
is considered unreliable (Wade and Angliss, 1997; Mullin and Fulling,

[[Page 52163]]

2003). However, this abundance estimate is the first and only estimate 
to date for this species in the U.S. Atlantic EEZ and represents the 
best abundance estimate.
    These eight species did not have density model outputs within the 
SERDP/NASA/NOAA and OBIS-SEAMAP database. However, limited OBIS-SEAMAP 
sightings data exist for these species within or adjacent to the action 
area. As explained above, even where the limited number of sightings 
suggests that density is very low and encounters are less likely, for 
any species with OBIS-SEAMAP sightings data within or adjacent to the 
action area, NMFS believes it is wise to include coverage for potential 
takes. Generally, to quantify this coverage, NMFS assumed that USGS 
could potentially encounter one group of each species during each of 
the seismic survey legs (recognizing that interannual variation and the 
potential presence of ephemeral features could drive differing 
encounter possibilities in the two legs), and NMFS thinks it is 
reasonable to use the average (mean) groups size (weighted by effort 
and rounded up) to estimate the take from these potential encounters. 
Therefore, even though we do not have abundance data for these species, 
because of the limited sightings and low probability of encountering 
them, we have predicted take of no more than two individual groups of 
each of these species of animals during the two legs of the survey. 
Qualitatively, given what is known about cetacean biology and the range 
of these species, two groups as a portion of the total population 
abundance within or without of the U.S. EEZ would be considered small 
for all eight species.

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. 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 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 independent 
actions. In August 2014, NMFS's Office of Protected Resources, 
Endangered Species Act Interagency Cooperation Division issued a 
Biological Opinion and concluded that both actions (i.e., the USGS 
seismic survey and NMFS's issuance of an IHA) are not likely to 
jeopardize the existence of cetaceans and sea turtles and would have no 
effect on critical habitat. NMFS's Office of Protected Resources, 
Endangered Species Act Interagency Cooperation Division also issued an 
Incidental Take Statement (ITS) incorporating the requirements of the 
IHA as Terms and Conditions of the ITS.

National Environmental Policy Act

    USGS provided NMFS with an ``Environmental Assessment for Seismic 
Reflection Scientific Research Surveys During 2014 and 2015 in Support 
of Mapping the U.S. Atlantic Seaboard Extended Continental Margin and 
Investigating Tsunami Hazards,'' (EA) prepared by RPS Evan-Hamilton, 
Inc., in association with YOLO Environmental, Inc., GeoSpatial Strategy 
Group, and Ecology and Environment, Inc., 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, after review and 
evaluation of the USGS EA for consistency with the regulations 
published by the Council of Environmental Quality (CEQ) and NOAA 
Administrative Order 216-6, Environmental Review Procedures for 
Implementing the National Environmental Policy Act, adopted the EA. 
After considering the EA, the information in the IHA application, 
Biological Opinion, and the Federal Register notice, as well as public 
comments, NMFS has determined that the issuance of the IHA is not 
likely to result in significant impacts on the human environment and 
has prepared a Finding of No Significant Impact (FONSI). An 
Environmental Impact Statement is not required and will not be prepared 
for the action.

Authorization

    NMFS has issued an IHA to the USGS for conducting a marine seismic 
survey in the northwest Atlantic Ocean off the Eastern Seaboard, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.

    Dated: August 22, 2014.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2014-20475 Filed 8-29-14; 8:45 am]
BILLING CODE 3510-22-P