[Federal Register Volume 80, Number 148 (Monday, August 3, 2015)]
[Rules and Regulations]
[Pages 46112-46171]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-18633]



[[Page 46111]]

Vol. 80

Monday,

No. 148

August 3, 2015

Part II





Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 218





Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy 
Training and Testing Activities in the Mariana Islands Training and 
Testing Study Area; Final Rule

  Federal Register / Vol. 80, No. 148 / Monday, August 3, 2015 / Rules 
and Regulations  

[[Page 46112]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 140211133-5621-01]
RIN 0648-BD69


Takes of Marine Mammals Incidental to Specified Activities; U.S. 
Navy Training and Testing Activities in the Mariana Islands Training 
and Testing Study Area

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

ACTION: Final rule.

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SUMMARY: Upon application from the U.S. Navy (Navy), we (the National 
Marine Fisheries Service) are issuing regulations under the Marine 
Mammal Protection Act (MMPA) to govern the unintentional taking of 
marine mammals incidental to training and testing activities conducted 
in the Mariana Islands Training and Testing (MITT) Study Area from 
August 2015 through August 2020. These regulations allow us to issue a 
Letter of Authorization (LOA) for the incidental take of marine mammals 
during the Navy's specified activities and timeframes, set forth the 
permissible methods of taking, set forth other means of effecting the 
least practicable adverse impact on marine mammal species or stocks and 
their habitat, and set forth requirements pertaining to the monitoring 
and reporting of the incidental take.

DATES: Effective August 3, 2015 through August 3, 2020.

ADDRESSES: To obtain an electronic copy of the Navy's application or 
other referenced documents, visit the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental/. Documents cited in this rule 
may also be viewed, by appointment, during regular business hours, at 
1315 East-West Highway, SSMC III, Silver Spring, MD 20912.

FOR FURTHER INFORMATION CONTACT: John Fiorentino, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION: 

Availability

    A copy of the Navy's application, which contains a list of the 
references used in this document, may be obtained by visiting the 
internet at: http://www.nmfs.noaa.gov/pr/permits/incidental. The Navy's 
Final Environmental Impact Statement/Overseas Environmental Impact 
Statement (FEIS/OEIS) for MITT, which also contains a list of the 
references used in this document, may be viewed at http://www.mitt-eis.com. Documents cited in this rule may also be viewed, by 
appointment, during regular business hours, at the aforementioned 
address (see ADDRESSES).

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. 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.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring, and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``an impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    The National Defense Authorization Act of 2004 (NDAA) (Pub. L. 108-
136) removed the ``small numbers'' and ``specified geographical 
region'' limitations indicated above and amended the definition of 
``harassment'' as it applies to a ``military readiness activity'' to 
read as follows (section 3(18)(B) of the MMPA): ``(i) Any act that 
injures or has the significant potential to injure a marine mammal or 
marine mammal stock in the wild [Level A Harassment]; or (ii) any act 
that disturbs or is likely to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of natural behavioral patterns, 
including, but not limited to, migration, surfacing, nursing, breeding, 
feeding, or sheltering, to a point where such behavioral patterns are 
abandoned or significantly altered [Level B Harassment].''

Summary of Request

    On April 22, 2013, NMFS received an application from the Navy 
requesting an LOA for the take of 26 species of marine mammals 
incidental to Navy training and testing activities to be conducted in 
the MITT Study Area over 5 years. The Navy is requesting regulations 
that would establish a process for authorizing take, via one 5-year 
LOA, of marine mammals for training and testing activities, proposed to 
be conducted from 2015 through 2020. The Study Area includes the 
existing Mariana Islands Range Complex (MIRC) and surrounding seas, a 
transit corridor between the Mariana Islands and the Navy's Hawaii 
Range Complex, and Navy pierside locations where sonar maintenance or 
testing may occur (see Figure 2-1 of the Navy's LOA application for a 
map of the MITT Study Area). These activities are classified as 
military readiness activities. Marine mammals present in the Study Area 
may be exposed to sound from active sonar and underwater detonations. 
The Navy is requesting authorization to take 26 marine mammal species 
by Level B harassment (behavioral) and two species by Level A 
harassment (injury).
    The Navy's application and the MITT FEIS/OEIS contain acoustic 
thresholds that, in some instances, represent changes from what NMFS 
has used to evaluate the Navy's activities for previous authorizations. 
The revised thresholds, which the Navy developed in coordination with 
NMFS, are based on the evaluation and inclusion of new information from 
recent scientific studies; a detailed explanation of how they were 
derived is provided in the MITT FEIS/OEIS Criteria and Thresholds 
Technical Report (available at http://www.mitt-eis.com). The revised 
thresholds are adopted for this rulemaking after providing the public 
with an opportunity for review and comment via the proposed rule for 
this action, which published on March 19, 2014 (79 FR 15388).
    Further, more generally, NMFS is committed to the use of the best 
available science. NMFS uses an adaptive transparent process that 
allows for both timely scientific updates and public input into agency 
decisions regarding the use of acoustic research and thresholds. NOAA 
is currently in the process of developing Acoustic Guidance (the 
Guidance) on thresholds for onset of auditory impacts from exposure to 
sound, which will be used to support assessments of the effects of 
anthropogenic sound on marine mammals. To develop this Guidance, NOAA 
is compiling, interpreting, and synthesizing the best information 
currently available on the effects of anthropogenic sound on marine 
mammals, and is committed to

[[Page 46113]]

finalizing the Guidance through a systematic, transparent process that 
involves internal review, external peer review, and public comment. In 
December 2013, NOAA released for public comment draft Acoustic Guidance 
that provides acoustic threshold levels for onset of permanent 
threshold shift (PTS) and temporary threshold shifts (TTS) in marine 
mammals for all sound sources. NOAA has since been working to 
incorporate the relevant information received during the public comment 
period and to make appropriate changes. In January 2015, while NOAA was 
still working to finalize the Guidance, the U.S. Navy provided NOAA 
with a technical paper by Finneran (2015) describing Navy's proposed 
methodology for updating auditory weighting functions and numeric 
thresholds for predicting onset of auditory effects (TTS/PTS 
thresholds) on marine animals exposed to active sonars and other active 
acoustic sources utilized during Navy training and testing activities. 
NOAA is working to evaluate and incorporate the information in Finneran 
(2015) into its Acoustic Guidance before it becomes final. Before doing 
so, NOAA will complete an independent peer review of the Navy's 
technical paper and provide an additional public comment period for the 
draft Guidance. After the second peer review and public comment 
processes are complete, NOAA will determine how best to incorporate the 
Navy's methodology into its final Acoustic Guidance. The Guidance 
likely will not be finalized until later this year. Thereafter, any new 
Navy modeling based on our final Acoustic Guidance would likely take a 
minimum of several months to complete. Consequently, the results of 
prior Navy modeling described in this rule represent the best available 
estimate of the number and type of take that may result from the Navy's 
use of acoustic sources in the MITT Study Area. NOAA's continued 
evaluation of all available science for the Acoustic Guidance could 
result in changes to the acoustic criteria used to model the Navy's 
activities in the MITT Study Area, and, consequently, the enumerations 
of ``take'' estimates. However, consideration of the draft Guidance and 
information contained in Finneran (2015) does not alter our assessment 
of the likely responses of affected marine mammal species to acoustic 
sources employed by Navy in the MITT Study Area, or the likely fitness 
consequences of those responses. Further, while acoustic criteria may 
also inform mitigation and monitoring decisions, the Navy has a robust 
adaptive management program that regularly addresses new information 
and allows for modification of mitigation and/or monitoring measures as 
appropriate.

Description of the Specified Activity

    The proposed rule (79 FR 15388, March 19, 2014) and MITT FEIS/OEIS 
include a complete description of the Navy's specified activities that 
are being authorized in this final rule. Sonar use and underwater 
detonations are the stressors most likely to result in impacts on 
marine mammals that could rise to the level of harassment. Detailed 
descriptions of these activities are provided in the MITT FEIS/OEIS and 
LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/) and 
are summarized here.

Overview of Training Activities

    The Navy, U.S. Air Force, U.S. Marine Corps, and U.S. Coast Guard 
routinely train in the MITT Study Area in preparation for national 
defense missions. Training activities are categorized into eight 
functional warfare areas (anti-air warfare; amphibious warfare; strike 
warfare; anti-surface warfare; anti-submarine warfare; electronic 
warfare; mine warfare; and naval special warfare). The Navy determined 
that the following stressors used in these warfare areas are most 
likely to result in impacts on marine mammals:

 Anti-surface warfare (underwater detonations)
 Anti-submarine warfare (active sonar, underwater detonations)
 Mine warfare (active sonar, underwater detonations)
 Naval special warfare (underwater detonations)

    Additionally, some activities described as Major Training 
Activities in the MITT FEIS/OEIS and other activities are included in 
the analysis. The Navy's activities in amphibious warfare, anti-air 
warfare, strike warfare, and electronic warfare do not involve 
stressors that could result in harassment of marine mammals. Therefore, 
these activities are not discussed further. The analysis and rationale 
for excluding these warfare areas are contained in the MITT FEIS/OEIS.

Overview of Testing Activities

    The Navy researches, develops, tests, and evaluates new platforms, 
systems, and technologies. Many tests are conducted in realistic 
conditions at sea, and can range in scale from testing new software to 
operating portable devices to conducting tests of live weapons to 
ensure they function as intended. Testing activities may occur 
independently of or in conjunction with training activities. Many 
testing activities are conducted similarly to Navy training activities 
and are also categorized under one of the primary mission areas. Other 
testing activities are unique and are described within their specific 
testing categories. The Navy determined that stressors used during the 
following testing activities are most likely to result in impacts on 
marine mammals:

 Naval Air Systems Command (NAVAIR) Testing
[cir] Anti-surface warfare testing (underwater detonations)
[cir] Anti-submarine warfare testing (active sonar, underwater 
detonations)
 Naval Sea Systems command (NAVSEA) Testing
[cir] New ship construction (active sonar, underwater detonations)
[cir] Life cycle activities (active sonar, underwater detonations)
[cir] Anti-surface warfare/anti-submarine warfare testing (active 
sonar, underwater detonations)
[cir] Ship protection systems and swimmer defense testing (active 
sonar)
 Office of Naval Research (ONR) and Naval Research Laboratory 
(NRL) Testing
[cir] ONR/NRL research, development, test, and evaluation (active 
sonar)

    Other Navy testing activities do not involve stressors that could 
result in marine mammal harassment. Therefore, these activities are not 
discussed further.

Classification of Non-Impulsive and Impulsive Sources Analyzed

    In order to better organize and facilitate the analysis of about 
300 sources of underwater non-impulsive sound or impulsive energy, the 
Navy developed a series of source classifications, or source bins. This 
method of analysis provides the following benefits:
     Allows for new sources to be covered under existing 
authorizations, as long as those sources fall within the parameters of 
a ``bin;''
     Simplifies the data collection and reporting requirements 
anticipated under the MMPA;
     Ensures a conservative approach to all impact analysis 
because all sources in a single bin are modeled as the loudest source 
(e.g., lowest frequency, highest source level, longest duty cycle, or 
largest net explosive weight within that bin);

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     Allows analysis to be conducted more efficiently, without 
compromising the results;
     Provides a framework to support the reallocation of source 
usage (hours/explosives) between different source bins, as long as the 
total number and severity of marine mammal takes remain within the 
overall analyzed and authorized limits. This flexibility is required to 
support evolving Navy training and testing requirements, which are 
linked to real world events.
    A description of each source classification is provided in Tables 1 
and 2. Non-impulsive sources are grouped into bins based on the 
frequency, source level when warranted, and how the source would be 
used. Impulsive bins are based on the net explosive weight of the 
munitions or explosive devices. The following factors further describe 
how non-impulsive sources are divided:

 Frequency of the non-impulsive source:
[cir] Low-frequency sources operate below 1 kilohertz (kHz)
[cir] Mid-frequency sources operate at or above 1 kHz, up to and 
including 10 kHz
[cir] High-frequency sources operate above 10 kHz, up to and including 
100 kHz
[cir] Very high-frequency sources operate above 100, but below 200 kHz
 Source level of the non-impulsive source:
[cir] Greater than 160 decibels (dB), but less than 180 dB
[cir] Equal to 180 dB and up to 200 dB
[cir] Greater than 200 dB

    How a sensor is used determines how the sensor's acoustic emissions 
are analyzed. Factors to consider include pulse length (time source is 
on); beam pattern (whether sound is emitted as a narrow, focused beam, 
or, as with most explosives, in all directions); and duty cycle (how 
often a transmission occurs in a given time period during an event).
    There are also non-impulsive sources with characteristics that are 
not anticipated to result in takes of marine mammals. These sources 
have low source levels, narrow beam widths, downward directed 
transmission, short pulse lengths, frequencies beyond known hearing 
ranges of marine mammals, or some combination of these factors. These 
sources generally have frequencies greater than 200 kHz and/or source 
levels less than 160 dB and are qualitatively analyzed in the MITT 
FEIS/OEIS.

                         Table 1--Impulsive Training and Testing Source Classes Analyzed
----------------------------------------------------------------------------------------------------------------
            Source class               Representative munitions             Net explosive weight  (lbs)
----------------------------------------------------------------------------------------------------------------
E1.................................  Medium-caliber projectiles.  0.1-0.25 (45.4-113.4 g)
E2.................................  Medium-caliber projectiles.  0.26-0.5 (117.9-226.8 g)
E3.................................  Large-caliber projectiles..  >0.5-2.5 (>226.8 g-1.1 kg)
E4.................................  Improved Extended Echo       >2.5-5.0 (1.1-2.3 kg)
                                      Ranging Sonobuoy.
E5.................................  5 in. (12.7 cm) projectiles  >5-10 (>2.3-4.5 kg)
E6.................................  15 lb. (6.8 kg) shaped       >10-20 (>4.5-9.1 kg)
                                      charge.
E8.................................  250 lb. (113.4 kg) bomb....  >60-100 (>27.2-45.4 kg)
E9.................................  500 lb. (226.8 kg) bomb....  >100-250 (>45.4-113.4 kg)
E10................................  1,000 lb. (453.6 kg) bomb..  >250-500 (>113.4-226.8 kg)
E11................................  650 lb. (294.8 kg) mine....  >500-650 (>226.8-294.8 kg)
E12................................  2,000 lb. (907.2 kg) bomb..  >650-1,000 (>294.8-453.6 kg)
----------------------------------------------------------------------------------------------------------------


   Table 2--Non-Impulsive Training and Testing Source Classes Analyzed
------------------------------------------------------------------------
    Source class category         Source class           Description
------------------------------------------------------------------------
Low-Frequency (LF): Sources   LF4                   Low-frequency
 that produce low-frequency   LF5                    sources equal to
 (less than 1 kilohertz                              180 dB and up to
 [kHz]) signals.                                     200 dB.
                                                    Low-frequency
                                                     sources less than
                                                     180 dB.
                              LF6                   Low-frequency sonar
                                                     currently in
                                                     development (e.g.,
                                                     anti-submarine
                                                     warfare sonar
                                                     associated with the
                                                     Littoral Combat
                                                     Ship).
Mid-Frequency (MF): Tactical  MF1                   Active hull-mounted
 and non-tactical sources                            surface ship sonar
 that produce mid-frequency                          (e.g., AN/SQS-53C
 (1 to 10 kHz) signals.                              and AN/SQS-60).
                              MF2                   Active hull-mounted
                                                     surface ship sonar
                                                     (e.g., AN/SQS-56).
                              MF3                   Active hull-mounted
                                                     submarine sonar
                                                     (e.g., AN/BQQ-10).
                              MF4                   Active helicopter-
                                                     deployed dipping
                                                     sonar (e.g., AN/AQS-
                                                     22 and AN/AQS-13).
                              MF5                   Active acoustic
                                                     sonobuoys (e.g.,
                                                     DICASS).
                              MF6                   Active underwater
                                                     sound signal
                                                     devices (e.g., MK-
                                                     84).
                              MF8                   Active sources
                                                     (greater than 200
                                                     dB) not otherwise
                                                     binned.
                              MF9                   Active sources
                                                     (equal to 180 dB
                                                     and up to 200 dB).
                              MF10                  Active sources
                                                     (greater than 160
                                                     dB, but less than
                                                     180 dB) not
                                                     otherwise binned.
                              MF11                  Hull-mounted surface
                                                     ship sonar with an
                                                     active duty cycle
                                                     greater than 80%.
                              MF12                  High duty cycle--
                                                     variable depth
                                                     sonar.
High-Frequency (HF) and Very  HF1                   Active hull-mounted
 High-Frequency (VHF):        HF4                    submarine sonar
 Tactical and non-tactical                           (e.g., AN/BQQ-10).
 sources that produce high-                         Active mine
 frequency (greater than 10                          detection,
 kHz but less than 200 kHz)                          classification, and
 signals.                                            neutralization
                                                     sonar (e.g., AN/SQS-
                                                     20).
                              HF5                   Active sources
                                                     (greater than 200
                                                     dB).
                              HF6                   Active sources
                                                     (equal to 180 dB
                                                     and up to 200 dB).
Anti-Submarine Warfare        ASW1                  MF active Deep Water
 (ASW): Tactical sources      ASW2                   Active Distributed
 such as active sonobuoys                            System (DWADS).
 and acoustic                                       MF active
 countermeasures systems                             Multistatic Active
 used during ASW training                            Coherent (MAC)
 and testing activities.                             sonobuoy (e.g., AN/
                                                     SSQ-125).

[[Page 46115]]

 
                              ASW3                  MF active towed
                                                     active acoustic
                                                     countermeasure
                                                     systems (e.g., AN/
                                                     SLQ-25).
Torpedoes (TORP): Source      TORP1                 Lightweight torpedo
 classes associated with                             (e.g., MK-46, MK-
 active acoustic signals                             54, or Anti-Torpedo
 produced by torpedoes.                              Torpedo).
                              TORP2                 Heavyweight torpedo
                                                     (e.g., MK-48).
Acoustic Modems (M): Systems  M3                    Mid-frequency
 used to transmit data                               acoustic modems
 acoustically through water.                         (greater than 190
                                                     dB).
Swimmer Detection Sonar       SD1                   High-frequency
 (SD): Systems used to                               sources with short
 detect divers and submerged                         pulse lengths, used
 swimmers.                                           for the detection
                                                     of swimmers and
                                                     other objects for
                                                     the purpose of port
                                                     security.
Airguns (AG) \1\: Underwater  AG                    Up to 60 cubic inch
 airguns are used during                             airguns (e.g.,
 swimmer defense and diver                           Sercel Mini-G).
 deterrent training and
 testing activities.
------------------------------------------------------------------------
\1\ There are no Level A or Level B takes proposed from airguns;
  therefore, airguns are not discussed further in this rule.

 Proposed Action

    The Navy proposes to continue conducting training and testing 
activities within the MITT Study Area. The Navy has been conducting 
military readiness training and testing activities in the MITT Study 
Area for decades.

Training and Testing

    The Navy proposes to conduct training and testing activities in the 
Study Area as described in Tables 3 and 4. Detailed information about 
each proposed activity (stressor, training or testing event, 
description, sound source, duration, and geographic location) can be 
found in the MITT FEIS/OEIS. NMFS used the detailed information in the 
MITT FEIS/OEIS to help analyze the potential impacts to marine mammals. 
Table 3 describes the annual number of impulsive source detonations 
during training and testing activities within the Study Area, and Table 
4 describes the annual number of hours or items of non-impulsive 
sources used during training and testing within the Study Area.

 Table 3--Annual Number of Impulsive Source Detonations During Training
                and Testing Activities in the Study Area
------------------------------------------------------------------------
                                                            Annual in-
          Explosive class           Net explosive weight       water
                                            (NEW)           detonations
------------------------------------------------------------------------
E1................................  (0.1 lb.-0.25 lb.)..          10,140
E2................................  (0.26 lb.-0.5 lb.)..             106
E3................................  (>0.5 lb.-2.5 lb.)..             932
E4................................  (>2.5 lb.-5 lb.)....             420
E5................................  (>5 lb.-10 lb.).....             684
E6................................  (>10 lb.-20 lb.)....              76
E8................................  (>60 lb.-100 lb.)...              16
E9................................  (>100 lb.-250 lb.)..               4
E10...............................  (>250 lb.-500 lb.)..              12
E11...............................  (>500 lb.-650 lb.)..               6
E12...............................  (>650 lb.-2,000 lb.)             184
------------------------------------------------------------------------


   Table 4--Annual Hours or Items of Non-Impulsive Sources Used During
          Training and Testing Activities Within the Study Area
------------------------------------------------------------------------
     Source class category           Source class          Annual use
------------------------------------------------------------------------
Low-Frequency (LF): Sources     LF4                     123 hours.
 that produce signals less
 than 1 kHz.
                                LF5                     11 hours.
                                LF6                     40 hours.
Mid-Frequency (MF): Tactical    MF1                     1,872 hours.
 and non-tactical sources from
 1 to 10 kHz.
                                MF2                     625 hours.
                                MF3                     192 hours.
                                MF4                     214 hours.
                                MF5                     2,588 items.
                                MF6                     33 items.
                                MF8                     123 hours.
                                MF9                     47 hours.
                                MF10                    231 hours.
                                MF11                    324 hours.
                                MF12                    656 hours.
High-Frequency (HF) and Very    HF1                     113 hours.
 High-Frequency (VHF):          HF4                     1,060 hours.
 Tactical and non-tactical
 sources that produce signals
 greater than 10 kHz but less
 than 200 kHz.
                                HF5                     336 hours.
                                HF6                     1,173 hours.
Anti-Submarine Warfare (ASW):   ASW1                    144 hours.
 Tactical sources used during   ASW2                    660 items.
 anti-submarine warfare
 training and testing
 activities.
                                ASW3                    3,935 hours.
                                ASW4                    32 items.
Torpedoes (TORP): Source        TORP1                   115 items.
 classes associated with        TORP2                   62 items.
 active acoustic signals
 produced by torpedoes.
Acoustic Modems (M): Transmit   M3                      112 hours.
 data acoustically through the
 water.
Swimmer Detection Sonar (SD):   SD1                     2,341 hours.
 Used to detect divers and
 submerged swimmers.
------------------------------------------------------------------------


[[Page 46116]]

Vessels

    Vessels used as part of the proposed action include ships, 
submarines, and boats ranging in size from small, 5-m Rigid Hull 
Inflatable Boats to 333-m long aircraft carriers. Representative Navy 
vessel types, lengths, and speeds used in both training and testing 
activities are shown in Table 5. While these speeds are representative, 
some vessels operate outside of these speeds due to unique training or 
safety requirements for a given event. Examples include increased 
speeds needed for flight operations, full speed runs to test 
engineering equipment, time critical positioning needs, etc. Examples 
of decreased speeds include speeds less than 5 knots or completely 
stopped for launching small boats, certain tactical maneuvers, target 
launch or retrievals, etc.
    The number of Navy vessels in the Study Area varies based on 
training and testing schedules. Most activities include either one or 
two vessels, with an average of one vessel per activity, and last from 
a few hours up to two weeks. Multiple ships, however, can be involved 
with major training events, although ships can often operate for 
extended periods beyond the horizon and out of visual sight from each 
other.

 Table 5--Typical Navy Boat and Vessel Types With Length Greater Than 18
                 Meters Used Within the MITT Study Area
------------------------------------------------------------------------
                                      Example(s)
                                  (specifications in
                                    meters (m) for     Typical operating
      Vessel type (>18 m)        length, metric tons     speed (knots)
                                  (mt) for mass, and
                                   knots for speed)
------------------------------------------------------------------------
Aircraft Carrier..............  Aircraft Carrier       10 to 15.
                                 (CVN) length: 333 m
                                 beam: 41 m draft: 12
                                 m displacement:
                                 81,284 mt max.
                                 speed: 30+ knots.
Surface Combatants............  Cruiser (CG) length:   10 to 15.
                                 173 m beam: 17 m
                                 draft: 10 m
                                 displacement: 9,754
                                 mt max. speed: 30+
                                 knots.
                                Destroyer (DDG)
                                 length: 155 m beam:
                                 18 m draft: 9 m
                                 displacement: 9,648
                                 mt max. speed: 30+
                                 knots.
                                Frigate (FFG) length:
                                 136 m beam: 14 m
                                 draft: 7 m
                                 displacement: 4,166
                                 mt max. speed: 30+
                                 knots.
                                Littoral Combat Ship
                                 (LCS) length: 115 m
                                 beam: 18 m draft: 4
                                 m displacement:
                                 3,000 mt max. speed:
                                 40+ knots.
Amphibious Warfare Ships......  Amphibious Assault     10 to 15.
                                 Ship (LHA, LHD)
                                 length: 253 m beam:
                                 32 m draft: 8 m
                                 displacement: 42,442
                                 mt max. speed: 20+
                                 knots.
                                Amphibious Transport
                                 Dock (LPD) length:
                                 208 m beam: 32 m
                                 draft: 7 m
                                 displacement: 25,997
                                 mt max. speed: 20+
                                 knots.
                                Dock Landing Ship
                                 (LSD) length: 186 m
                                 beam: 26 m draft: 6
                                 m displacement:
                                 16,976 mt max.
                                 speed: 20+ knots.
Mine Warship Ship.............  Mine Countermeasures   5 to 8.
                                 Ship (MCM) length:
                                 68 m beam: 12 m
                                 draft: 4 m
                                 displacement: 1,333
                                 max. speed: 14 knots.
Submarines....................  Attack Submarine       8 to 13.
                                 (SSN) length: 115 m
                                 beam: 12 m draft: 9
                                 m displacement:
                                 12,353 mt max.
                                 speed: 20+ knots.
                                Guided Missile
                                 Submarine (SSGN)
                                 length: 171 m beam:
                                 13 m draft: 12 m
                                 displacement: 19,000
                                 mt max. speed: 20+
                                 knots.
Combat Logistics Force Ships    Fast Combat Support    8 to 12.
 \1\.                            Ship (T-AOE) length:
                                 230 m beam: 33 m
                                 draft: 12 m
                                 displacement: 49,583
                                 max. speed: 25 knots.
                                Dry Cargo/Ammunition
                                 Ship (T-AKE) length:
                                 210 m beam: 32 m
                                 draft: 9 m
                                 displacement: 41,658
                                 mt max speed: 20
                                 knots.
                                Fleet Replenishment
                                 Oilers (T-AO)
                                 length: 206 m beam:
                                 30 m draft: 11
                                 displacement: 42,674
                                 mt max. speed: 20
                                 knots.
                                Fleet Ocean Tugs (T-
                                 ATF) length: 69 m
                                 beam: 13 m draft: 5
                                 m displacement:
                                 2,297 max. speed: 14
                                 knots.
                                Joint High Speed
                                 Vessel (JHSV) \2\
                                 length: 103 m beam;
                                 28.5 m draft; 4.57 m
                                 displacement; 2,362
                                 mt max speed: 40
                                 knots.
Support Craft/Other...........  Landing Craft,         3 to 5.
                                 Utility (LCU)
                                 length: 41 m beam: 9
                                 m draft: 2 m
                                 displacement: 381 mt
                                 max. speed: 11 knots.
                                Landing Craft,
                                 Mechanized (LCM)
                                 length: 23 m beam: 6
                                 m draft: 1 m
                                 displacement: 107 mt
                                 max. speed: 11 knots.
Support Craft/Other             MK V Special           Variable.
 Specialized High Speed.         Operations Craft
                                 length: 25 m beam: 5
                                 m displacement: 52
                                 mt max. speed: 50
                                 knots.
------------------------------------------------------------------------
\1\ CLF vessels are not permanently homeported in the Marianas, but are
  used for various fleet support and training support events in the
  Study Area.
\2\ Typical operating speed of the Joint High Speed Vessel is 25-32
  knots.

Dates and Location

    The description of the location of authorized activities has not 
changed from what was provided in the proposed rule (79 FR 15388, March 
19, 2014; pages 15394-15395) and MITT FEIS/OEIS (http://www.mitt-eis.com). For a complete description, please see those documents. 
Training and testing activities will be conducted in the MITT Study 
Area for the reasonably foreseeable future. The MITT Study Area is 
comprised of the established ranges, operating areas, and special use 
airspace in the region of the Mariana Islands that are part of the 
Mariana Islands Range Complex (MIRC), its surrounding seas, and a 
transit corridor between the Mariana Islands and the Hawaii Range 
Complex. The defined Study Area has expanded beyond the areas included 
in previous Navy authorizations to include transit routes and pierside 
locations. This expansion is not an increase in the Navy's training and 
testing area, but rather an increase in the area to be analyzed (i.e., 
not previously analyzed) under an incidental take authorization in 
support of the MITT EIS/OEIS. The MIRC, like

[[Page 46117]]

all Navy range complexes, is an organized and designated set of 
specifically bounded geographic areas, which includes a water component 
(above and below the surface), airspace, and sometimes a land 
component. Operating areas (OPAREAs) and special use airspace are 
established within each range complex. These designations are further 
described in Chapter 2 of the Navy's LOA application.

Description of Marine Mammals in the Area of the Specified Activity

    Twenty-six marine mammal species may occur in the Study Area, 
including seven mysticetes (baleen whales) and 19 odontocetes (dolphins 
and toothed whales). The Description of Marine Mammals in the Area of 
the Specified Activities section has not changed from what was in the 
proposed rule (79 FR 15388, March 19, 2014; pages 15395-15396). Table 6 
of the proposed rule provided a list of marine mammals with possible or 
confirmed occurrence within the MITT Study Area, including stock, 
abundance, and status. Since publishing the proposed rule, NMFS 
released new stock assessment reports for some of the marine mammal 
species occurring within the MITT Study Area. The new species abundance 
estimates were considered in making our final determinations. The MITT 
FEIS/OEIS includes the revised species abundance estimates. Although 
not repeated in this final rule, we have reviewed these data, 
determined them to be the best available scientific information for the 
purposes of the rulemaking, and consider this information part of the 
administrative record for this action.
    The proposed rule, the Navy's LOA application, and the MITT FEIS/
OEIS include a complete description of information on the status, 
distribution, abundance, vocalizations, density estimates, and general 
biology of marine mammal species in the Study Area. In addition, NMFS 
publishes annual stock assessment reports for marine mammals, including 
some stocks that occur within the Study Area (http://www.nmfs.noaa.gov/pr/species/mammals).

Potential Effects of Specified Activities on Marine Mammals

    The Navy has requested authorization for the take of marine mammals 
that may occur incidental to training and testing activities in the 
Study Area. The Navy has analyzed potential impacts to marine mammals 
from impulsive and non-impulsive sound sources and vessel strike.
    Other potential impacts to marine mammals from training activities 
in the Study Area were analyzed in the MITT FEIS/OEIS, in consultation 
with NMFS as a cooperating agency, and determined to be unlikely to 
result in marine mammal harassment. Therefore, the Navy has not 
requested authorization for take of marine mammals that might occur 
incidental to other components of their proposed activities. In this 
document, NMFS analyzes the potential effects on marine mammals from 
exposure to non-impulsive sound sources (sonar and other active 
acoustic sources), impulsive sound sources (underwater detonations), 
and vessel strikes.
    For the purpose of MMPA authorizations, NMFS' effects assessments 
serve four primary purposes: (1) To prescribe the permissible methods 
of taking (i.e., Level B harassment (behavioral harassment), Level A 
harassment (injury), or mortality, including an identification of the 
number and types of take that could occur by harassment or mortality) 
and to prescribe other means of effecting the least practicable adverse 
impact on such species or stock and its habitat (i.e., mitigation); (2) 
to determine whether the specified activity would have a negligible 
impact on the affected species or stocks of marine mammals (based on 
the likelihood that the activity would adversely affect the species or 
stock through effects on annual rates of recruitment or survival); (3) 
to determine whether the specified activity would have an unmitigable 
adverse impact on the availability of the species or stock(s) for 
subsistence uses; and (4) to prescribe requirements pertaining to 
monitoring and reporting.
    This section focuses qualitatively on the different ways that non-
impulsive and impulsive sources may affect marine mammals (some of 
which NMFS would not classify as harassment). In the Estimated Take 
section, we will relate the potential effects to marine mammals from 
non-impulsive and impulsive sources to the MMPA definitions of Level A 
and Level B harassment and will attempt to quantify those effects.

Non-Impulsive Sources

Direct Physiological Effects

    Based on the literature, there are two basic ways that non-
impulsive sources might directly result in physical trauma or damage: 
Noise-induced loss of hearing sensitivity (more commonly-called 
``threshold shift'') and acoustically mediated bubble growth. 
Separately, an animal's behavioral reaction to an acoustic exposure 
could lead to physiological effects that might ultimately lead to 
injury or death, which is discussed later in the Stranding section.
    Threshold Shift (noise-induced loss of hearing)--When animals 
exhibit reduced hearing sensitivity (i.e., sounds must be louder for an 
animal to detect them) following exposure to an intense sound or sound 
for long duration, it is referred to as a noise-induced threshold shift 
(TS). An animal can experience TTS or PTS. TTS can last from minutes or 
hours to days (i.e., there is complete recovery), can occur in specific 
frequency ranges (i.e., an animal might only have a temporary loss of 
hearing sensitivity between the frequencies of 1 and 10 kHz), and can 
be of varying amounts (for example, an animal's hearing sensitivity 
might be reduced initially by only 6 dB or reduced by 30 dB). PTS is 
permanent, but some recovery is possible. PTS can also occur in a 
specific frequency range and amount as mentioned above for TTS.
    The following physiological mechanisms are thought to play a role 
in inducing auditory TS: Effects to sensory hair cells in the inner ear 
that reduce their sensitivity, modification of the chemical environment 
within the sensory cells, residual muscular activity in the middle ear, 
displacement of certain inner ear membranes, increased blood flow, and 
post-stimulatory reduction in both efferent and sensory neural output 
(Southall et al., 2007). The amplitude, duration, frequency, temporal 
pattern, and energy distribution of sound exposure all can affect the 
amount of associated TS and the frequency range in which it occurs. As 
amplitude and duration of sound exposure increase, so, generally, does 
the amount of TS, along with the recovery time. For intermittent 
sounds, less TS could occur than compared to a continuous exposure with 
the same energy (some recovery could occur between intermittent 
exposures depending on the duty cycle between sounds) (Kryter et al., 
1966; Ward, 1997). For example, one short but loud (higher SPL) sound 
exposure may induce the same impairment as one longer but softer sound, 
which in turn may cause more impairment than a series of several 
intermittent softer sounds with the same total energy (Ward, 1997). 
Additionally, though TTS is temporary, prolonged exposure to sounds 
strong enough to elicit TTS, or shorter-term exposure to sound levels 
well above the TTS threshold, can cause PTS, at least in terrestrial 
mammals (Kryter, 1985). Although in the case of mid- and high-frequency 
active sonar (MFAS/HFAS), animals are not expected to be exposed to 
levels high

[[Page 46118]]

enough or durations long enough to result in PTS.
    PTS is considered auditory injury (Southall et al., 2007). 
Irreparable damage to the inner or outer cochlear hair cells may cause 
PTS; however, other mechanisms are also involved, such as exceeding the 
elastic limits of certain tissues and membranes in the middle and inner 
ears and resultant changes in the chemical composition of the inner ear 
fluids (Southall et al., 2007).
    Although the published body of scientific literature contains 
numerous theoretical studies and discussion papers on hearing 
impairments that can occur with exposure to a loud sound, only a few 
studies provide empirical information on the levels at which noise-
induced loss in hearing sensitivity occurs in nonhuman animals. For 
marine mammals, published data are limited to the captive bottlenose 
dolphin, beluga, harbor porpoise, and Yangtze finless porpoise 
(Finneran et al., 2000, 2002b, 2003, 2005a, 2007, 2010a, 2010b; 
Finneran and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 2009a, 
2009b; Popov et al., 2011a, 2011b; Kastelein et al., 2012a; Schlundt et 
al., 2000; Nachtigall et al., 2003, 2004). For pinnipeds in water, data 
are limited to measurements of TTS in harbor seals, an elephant seal, 
and California sea lions (Kastak et al., 1999, 2005; Kastelein et al., 
2012b).
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to serious 
(similar to those discussed in auditory masking, below). For example, a 
marine mammal may be able to readily compensate for a brief, relatively 
small amount of TTS in a non-critical frequency range that occurs 
during a time where ambient noise is lower and there are not as many 
competing sounds present. Alternatively, a larger amount and longer 
duration of TTS sustained during time when communication is critical 
for successful mother/calf interactions could have more serious 
impacts. Also, depending on the degree and frequency range, the effects 
of PTS on an animal could range in severity, although it is considered 
generally more serious because it is a permanent condition. Of note, 
reduced hearing sensitivity as a simple function of aging has been 
observed in marine mammals, as well as humans and other taxa (Southall 
et al., 2007), so one can infer that strategies exist for coping with 
this condition to some degree, though likely not without cost.
    Acoustically Mediated Bubble Growth--One theoretical cause of 
injury to marine mammals is rectified diffusion (Crum and Mao, 1996), 
the process of increasing the size of a bubble by exposing it to a 
sound field. This process could be facilitated if the environment in 
which the ensonified bubbles exist is supersaturated with gas. 
Repetitive diving by marine mammals can cause the blood and some 
tissues to accumulate gas to a greater degree than is supported by the 
surrounding environmental pressure (Ridgway and Howard, 1979). The 
deeper and longer dives of some marine mammals (for example, beaked 
whales) are theoretically predicted to induce greater supersaturation 
(Houser et al., 2001b). If rectified diffusion were possible in marine 
mammals exposed to high-level sound, conditions of tissue 
supersaturation could theoretically speed the rate and increase the 
size of bubble growth. Subsequent effects due to tissue trauma and 
emboli would presumably mirror those observed in humans suffering from 
decompression sickness.
    It is unlikely that the short duration of sonar pings or explosion 
sounds would be long enough to drive bubble growth to any substantial 
size, if such a phenomenon occurs. However, an alternative but related 
hypothesis has also been suggested: Stable bubbles could be 
destabilized by high-level sound exposures such that bubble growth then 
occurs through static diffusion of gas out of the tissues. In such a 
scenario the marine mammal would need to be in a gas-supersaturated 
state for a long enough period of time for bubbles to become of a 
problematic size. Recent research with ex vivo supersaturated bovine 
tissues suggested that, for a 37 kHz signal, a sound exposure of 
approximately 215 dB referenced to (re) 1 [mu]Pa would be required 
before microbubbles became destabilized and grew (Crum et al., 2005). 
Assuming spherical spreading loss and a nominal sonar source level of 
235 dB re 1 [mu]Pa at 1 m, a whale would need to be within 10 m (33 
ft.) of the sonar dome to be exposed to such sound levels. Furthermore, 
tissues in the study were supersaturated by exposing them to pressures 
of 400-700 kilopascals for periods of hours and then releasing them to 
ambient pressures. Assuming the equilibration of gases with the tissues 
occurred when the tissues were exposed to the high pressures, levels of 
supersaturation in the tissues could have been as high as 400-700 
percent. These levels of tissue supersaturation are substantially 
higher than model predictions for marine mammals (Houser et al., 2001; 
Saunders et al., 2008). It is improbable that this mechanism is 
responsible for stranding events or traumas associated with beaked 
whale strandings. Both the degree of supersaturation and exposure 
levels observed to cause microbubble destabilization are unlikely to 
occur, either alone or in concert.
    Yet another hypothesis (decompression sickness) has speculated that 
rapid ascent to the surface following exposure to a startling sound 
might produce tissue gas saturation sufficient for the evolution of 
nitrogen bubbles (Jepson et al., 2003; Fernandez et al., 2005; 
Fern[aacute]ndez et al., 2012). In this scenario, the rate of ascent 
would need to be sufficiently rapid to compromise behavioral or 
physiological protections against nitrogen bubble formation. 
Alternatively, Tyack et al. (2006) studied the deep diving behavior of 
beaked whales and concluded that: ``Using current models of breath-hold 
diving, we infer that their natural diving behavior is inconsistent 
with known problems of acute nitrogen supersaturation and embolism.'' 
Collectively, these hypotheses can be referred to as ``hypotheses of 
acoustically mediated bubble growth.''
    Although theoretical predictions suggest the possibility for 
acoustically mediated bubble growth, there is considerable disagreement 
among scientists as to its likelihood (Piantadosi and Thalmann, 2004; 
Evans and Miller, 2003). Crum and Mao (1996) hypothesized that received 
levels would have to exceed 190 dB in order for there to be the 
possibility of significant bubble growth due to supersaturation of 
gases in the blood (i.e., rectified diffusion). More recent work 
conducted by Crum et al. (2005) demonstrated the possibility of 
rectified diffusion for short duration signals, but at SELs and tissue 
saturation levels that are highly improbable to occur in diving marine 
mammals. To date, energy levels (ELs) predicted to cause in vivo bubble 
formation within diving cetaceans have not been evaluated (NOAA, 
2002b). Although it has been argued that traumas from some recent 
beaked whale strandings are consistent with gas emboli and bubble-
induced tissue separations (Jepson et al., 2003), there is no 
conclusive evidence of this. However, Jepson et al. (2003, 2005) and 
Fernandez et al. (2004, 2005, 2012) concluded that in vivo bubble 
formation, which may be exacerbated by

[[Page 46119]]

deep, long-duration, repetitive dives may explain why beaked whales 
appear to be particularly vulnerable to sonar exposures. Further 
investigation is needed to further assess the potential validity of 
these hypotheses. More information regarding hypotheses that attempt to 
explain how behavioral responses to non-impulsive sources can lead to 
strandings is included in the Stranding and Mortality section.

Acoustic Masking

    Marine mammals use acoustic signals for a variety of purposes, 
which differ among species, but include communication between 
individuals, navigation, foraging, reproduction, and learning about 
their environment (Erbe and Farmer, 2000; Tyack, 2000). Masking, or 
auditory interference, generally occurs when sounds in the environment 
are louder than and of a similar frequency to, auditory signals an 
animal is trying to receive. Masking is a phenomenon that affects 
animals that are trying to receive acoustic information about their 
environment, including sounds from other members of their species, 
predators, prey, and sounds that allow them to orient in their 
environment. Masking these acoustic signals can disturb the behavior of 
individual animals, groups of animals, or entire populations.
    The extent of the masking interference depends on the spectral, 
temporal, and spatial relationships between the signals an animal is 
trying to receive and the masking noise, in addition to other factors. 
In humans, significant masking of tonal signals occurs as a result of 
exposure to noise in a narrow band of similar frequencies. As the sound 
level increases, though, the detection of frequencies above those of 
the masking stimulus decreases also. This principle is expected to 
apply to marine mammals as well because of common biomechanical 
cochlear properties across taxa.
    Richardson et al. (1995b) argued that the maximum radius of 
influence of an industrial noise (including broadband low frequency 
sound transmission) on a marine mammal is the distance from the source 
to the point at which the noise can barely be heard. This range is 
determined by either the hearing sensitivity of the animal or the 
background noise level present. Industrial masking is most likely to 
affect some species' ability to detect communication calls and natural 
sounds (i.e., surf noise, prey noise, etc.; Richardson et al., 1995).
    The echolocation calls of toothed whales are subject to masking by 
high frequency sound. Human data indicate low-frequency sound can mask 
high-frequency sounds (i.e., upward masking). Studies on captive 
odontocetes by Au et al. (1974, 1985, 1993) indicate that some species 
may use various processes to reduce masking effects (e.g., adjustments 
in echolocation call intensity or frequency as a function of background 
noise conditions). There is also evidence that the directional hearing 
abilities of odontocetes are useful in reducing masking at the high-
frequencies these cetaceans use to echolocate, but not at the low-to-
moderate frequencies they use to communicate (Zaitseva et al., 1980). A 
recent study by Nachtigall and Supin (2008) showed that false killer 
whales adjust their hearing to compensate for ambient sounds and the 
intensity of returning echolocation signals.
    As mentioned previously, the functional hearing ranges of 
mysticetes, odontocetes, and pinnipeds underwater all encompass the 
frequencies of the sonar sources used in the Navy's MFAS/HFAS training 
exercises. Additionally, almost all species' vocal repertoires span 
across the frequencies of these sonar sources used by the Navy. The 
closer the characteristics of the masking signal to the signal of 
interest, the more likely masking is to occur. For hull-mounted sonar, 
which accounts for the largest takes of marine mammals (because of the 
source strength and number of hours it's conducted), the pulse length 
and low duty cycle of the MFAS/HFAS signal makes it less likely that 
masking would occur as a result.

Impaired Communication

    In addition to making it more difficult for animals to perceive 
acoustic cues in their environment, anthropogenic sound presents 
separate challenges for animals that are vocalizing. When they 
vocalize, animals are aware of environmental conditions that affect the 
``active space'' of their vocalizations, which is the maximum area 
within which their vocalizations can be detected before it drops to the 
level of ambient noise (Brenowitz, 2004; Brumm et al., 2004; Lohr et 
al., 2003). Animals are also aware of environmental conditions that 
affect whether listeners can discriminate and recognize their 
vocalizations from other sounds, which is more important than simply 
detecting that a vocalization is occurring (Brenowitz, 1982; Brumm et 
al., 2004; Dooling, 2004, Marten and Marler, 1977; Patricelli et al., 
2006). Most animals that vocalize have evolved with an ability to make 
adjustments to their vocalizations to increase the signal-to-noise 
ratio, active space, and recognizability/distinguishability of their 
vocalizations in the face of temporary changes in background noise 
(Brumm et al., 2004; Patricelli et al., 2006). Vocalizing animals can 
make adjustments to vocalization characteristics such as the frequency 
structure, amplitude, temporal structure, and temporal delivery.
    Many animals will combine several of these strategies to compensate 
for high levels of background noise. Anthropogenic sounds that reduce 
the signal-to-noise ratio of animal vocalizations, increase the masked 
auditory thresholds of animals listening for such vocalizations, or 
reduce the active space of an animal's vocalizations impair 
communication between animals. Most animals that vocalize have evolved 
strategies to compensate for the effects of short-term or temporary 
increases in background or ambient noise on their songs or calls. 
Although the fitness consequences of these vocal adjustments remain 
unknown, like most other trade-offs animals must make, some of these 
strategies probably come at a cost (Patricelli et al., 2006). For 
example, vocalizing more loudly in noisy environments may have 
energetic costs that decrease the net benefits of vocal adjustment and 
alter a bird's energy budget (Brumm, 2004; Wood and Yezerinac, 2006). 
Shifting songs and calls to higher frequencies may also impose 
energetic costs (Lambrechts, 1996).

Stress Responses

    Classic stress responses begin when an animal's central nervous 
system perceives a potential threat to its homeostasis. That perception 
triggers stress responses regardless of whether a stimulus actually 
threatens the animal; the mere perception of a threat is sufficient to 
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle, 
1950). Once an animal's central nervous system perceives a threat, it 
mounts a biological response or defense that consists of a combination 
of the four general biological defense responses: Behavioral responses, 
autonomic nervous system responses, neuroendocrine responses, or immune 
responses.
    In the case of many stressors, an animal's first and sometimes most 
economical (in terms of biotic costs) response is behavioral avoidance 
of the potential stressor or avoidance of continued exposure to a 
stressor. An animal's second line of defense to stressors involves the 
sympathetic part of the autonomic nervous system and the classical 
``fight or flight'' response which includes the cardiovascular system, 
the gastrointestinal system, the

[[Page 46120]]

exocrine glands, and the adrenal medulla to produce changes in heart 
rate, blood pressure, and gastrointestinal activity that humans 
commonly associate with ``stress.'' These responses have a relatively 
short duration and may or may not have significant long-term effect on 
an animal's welfare.
    An animal's third line of defense to stressors involves its 
neuroendocrine systems; the system that has received the most study has 
been the hypothalmus-pituitary-adrenal system (also known as the HPA 
axis in mammals or the hypothalamus-pituitary-interrenal axis in fish 
and some reptiles). Unlike stress responses associated with the 
autonomic nervous system, virtually all neuro-endocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction (Moberg, 1987; Rivier, 1995), altered 
metabolism (Elasser et al., 2000), reduced immune competence (Blecha, 
2000), and behavioral disturbance. Increases in the circulation of 
glucocorticosteroids (cortisol, corticosterone, and aldosterone in 
marine mammals; see Romano et al., 2004) have been equated with stress 
for many years.
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and distress is the biotic cost 
of the response. During a stress response, an animal uses glycogen 
stores that can be quickly replenished once the stress is alleviated. 
In such circumstances, the cost of the stress response would not pose a 
risk to the animal's welfare. However, when an animal does not have 
sufficient energy reserves to satisfy the energetic costs of a stress 
response, energy resources must be diverted from other biotic function, 
which impairs those functions that experience the diversion. For 
example, when mounting a stress response diverts energy away from 
growth in young animals, those animals may experience stunted growth. 
When mounting a stress response diverts energy from a fetus, an 
animal's reproductive success and its fitness will suffer. In these 
cases, the animals will have entered a pre-pathological or pathological 
state which is called ``distress'' (Seyle, 1950) or ``allostatic 
loading'' (McEwen and Wingfield, 2003). This pathological state will 
last until the animal replenishes its biotic reserves sufficient to 
restore normal function. Note that these examples involved a long-term 
(days or weeks) stress response exposure to stimuli.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses have also been documented 
fairly well through controlled experiments; because this physiology 
exists in every vertebrate that has been studied, it is not surprising 
that stress responses and their costs have been documented in both 
laboratory and free-living animals (for examples see, Holberton et al., 
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004; 
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer, 
2000). Information has also been collected on the physiological 
responses of marine mammals to exposure to anthropogenic sounds (Fair 
and Becker, 2000; Romano et al., 2002; Wright et al., 2008). For 
example, Rolland et al. (2012) found that noise reduction from reduced 
ship traffic in the Bay of Fundy was associated with decreased stress 
in North Atlantic right whales. In a conceptual model developed by the 
Population Consequences of Acoustic Disturbance (PCAD) working group, 
serum hormones were identified as possible indicators of behavioral 
effects that are translated into altered rates of reproduction and 
mortality. The Office of Naval Research hosted a workshop (Effects of 
Stress on Marine Mammals Exposed to Sound) in 2009 that focused on this 
very topic (ONR, 2009).
    Studies of other marine animals and terrestrial animals would also 
lead us to expect some marine mammals to experience physiological 
stress responses and, perhaps, physiological responses that would be 
classified as ``distress'' upon exposure to high frequency, mid-
frequency and low-frequency sounds. For example, Jansen (1998) reported 
on the relationship between acoustic exposures and physiological 
responses that are indicative of stress responses in humans (for 
example, elevated respiration and increased heart rates). Jones (1998) 
reported on reductions in human performance when faced with acute, 
repetitive exposures to acoustic disturbance. Trimper et al. (1998) 
reported on the physiological stress responses of osprey to low-level 
aircraft noise, while Krausman et al. (2004) reported on the auditory 
and physiology stress responses of endangered Sonoran pronghorn to 
military overflights. Smith et al. (2004a, 2004b), for example, 
identified noise-induced physiological transient stress responses in 
hearing-specialist fish (i.e., goldfish) that accompanied short- and 
long-term hearing losses. Welch and Welch (1970) reported physiological 
and behavioral stress responses that accompanied damage to the inner 
ears of fish and several mammals.
    Hearing is one of the primary senses marine mammals use to gather 
information about their environment and to communicate with 
conspecifics. Although empirical information on the relationship 
between sensory impairment (TTS, PTS, and acoustic masking) on marine 
mammals remains limited, it seems reasonable to assume that reducing an 
animal's ability to gather information about its environment and to 
communicate with other members of its species would be stressful for 
animals that use hearing as their primary sensory mechanism. Therefore, 
we assume that acoustic exposures sufficient to trigger onset PTS or 
TTS would be accompanied by physiological stress responses because 
terrestrial animals exhibit those responses under similar conditions 
(NRC, 2003). More importantly, marine mammals might experience stress 
responses at received levels lower than those necessary to trigger 
onset TTS. Based on empirical studies of the time required to recover 
from stress responses (Moberg, 2000), we also assume that stress 
responses are likely to persist beyond the time interval required for 
animals to recover from TTS and might result in pathological and pre-
pathological states that would be as significant as behavioral 
responses to TTS.

Behavioral Disturbance

    Behavioral responses to sound are highly variable and context-
specific. Many different variables can influence an animal's perception 
of and response to (nature and magnitude) an acoustic event. An 
animal's prior experience with a sound or sound source effects whether 
it is less likely (habituation) or more likely (sensitization) to 
respond to certain sounds in the future (animals can also be innately 
pre-disposed to respond to certain sounds in certain ways) (Southall et 
al., 2007). Related to the sound itself, the perceived nearness of the 
sound, bearing of the sound (approaching vs. retreating), similarity of 
a sound to biologically relevant sounds in the animal's environment 
(i.e., calls of predators, prey, or conspecifics), and familiarity of 
the sound may affect the way an animal responds to the sound (Southall 
et al., 2007). Individuals (of different age, gender, reproductive 
status, etc.) among most populations will have variable hearing 
capabilities, and differing behavioral sensitivities to sounds that 
will be affected by prior conditioning,

[[Page 46121]]

experience, and current activities of those individuals. Often, 
specific acoustic features of the sound and contextual variables (i.e., 
proximity, duration, or recurrence of the sound or the current behavior 
that the marine mammal is engaged in or its prior experience), as well 
as entirely separate factors such as the physical presence of a nearby 
vessel, may be more relevant to the animal's response than the received 
level alone.
    Exposure of marine mammals to sound sources can result in no 
response or responses including, but not limited to: Increased 
alertness; orientation or attraction to a sound source; vocal 
modifications; cessation of feeding; cessation of social interaction; 
alteration of movement or diving behavior; habitat abandonment 
(temporary or permanent); and, in severe cases, panic, flight, 
stampede, or stranding, potentially resulting in death (Southall et 
al., 2007). A review of marine mammal responses to anthropogenic sound 
was first conducted by Richardson and others in 1995. A more recent 
review (Nowacek et al., 2007) addresses studies conducted since 1995 
and focuses on observations where the received sound level of the 
exposed marine mammal(s) was known or could be estimated. The following 
sub-sections provide examples of behavioral responses that provide an 
idea of the variability in behavioral responses that would be expected 
given the differential sensitivities of marine mammal species to sound 
and the wide range of potential acoustic sources to which a marine 
mammal may be exposed. Estimates of the types of behavioral responses 
that could occur for a given sound exposure should be determined from 
the literature that is available for each species, or extrapolated from 
closely related species when no information exists.
    Flight Response--A flight response is a dramatic change in normal 
movement to a directed and rapid movement away from the perceived 
location of a sound source. Relatively little information on flight 
responses of marine mammals to anthropogenic signals exist, although 
observations of flight responses to the presence of predators have 
occurred (Connor and Heithaus, 1996). Flight responses have been 
speculated as being a component of marine mammal strandings associated 
with sonar activities (Evans and England, 2001).
    Response to Predator--Evidence suggests that at least some marine 
mammals have the ability to acoustically identify potential predators. 
For example, harbor seals that reside in the coastal waters off British 
Columbia are frequently targeted by certain groups of killer whales, 
but not others. The seals discriminate between the calls of threatening 
and non-threatening killer whales (Deecke et al., 2002), a capability 
that should increase survivorship while reducing the energy required 
for attending to and responding to all killer whale calls. The 
occurrence of masking or hearing impairment provides a means by which 
marine mammals may be prevented from responding to the acoustic cues 
produced by their predators. Whether or not this is a possibility 
depends on the duration of the masking/hearing impairment and the 
likelihood of encountering a predator during the time that predator 
cues are impeded.
    Diving--Changes in dive behavior can vary widely. They may consist 
of increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive. Variations in 
dive behavior may reflect interruptions in biologically significant 
activities (e.g., foraging) or they may be of little biological 
significance. Variations in dive behavior may also expose an animal to 
potentially harmful conditions (e.g., increasing the chance of ship-
strike) or may serve as an avoidance response that enhances 
survivorship. The impact of a variation in diving resulting from an 
acoustic exposure depends on what the animal is doing at the time of 
the exposure and the type and magnitude of the response.
    Nowacek et al. (2004) reported disruptions of dive behaviors in 
foraging North Atlantic right whales when exposed to an alerting 
stimulus, an action, they noted, that could lead to an increased 
likelihood of ship strike. However, the whales did not respond to 
playbacks of either right whale social sounds or vessel noise, 
highlighting the importance of the sound characteristics in producing a 
behavioral reaction. Conversely, Indo-Pacific humpback dolphins have 
been observed to dive for longer periods of time in areas where vessels 
were present and/or approaching (Ng and Leung, 2003). In both of these 
studies, the influence of the sound exposure cannot be decoupled from 
the physical presence of a surface vessel, thus complicating 
interpretations of the relative contribution of each stimulus to the 
response. Indeed, the presence of surface vessels, their approach, and 
speed of approach, seemed to be significant factors in the response of 
the Indo-Pacific humpback dolphins (Ng and Leung, 2003). Low frequency 
signals of the Acoustic Thermometry of Ocean Climate (ATOC) sound 
source were not found to affect dive times of humpback whales in 
Hawaiian waters (Frankel and Clark, 2000) or to overtly affect elephant 
seal dives (Costa et al., 2003). They did, however, produce subtle 
effects that varied in direction and degree among the individual seals, 
illustrating the equivocal nature of behavioral effects and consequent 
difficulty in defining and predicting them.
    Due to past incidents of beaked whale strandings associated with 
sonar operations, feedback paths are provided between avoidance and 
diving and indirect tissue effects. This feedback accounts for the 
hypothesis that variations in diving behavior and/or avoidance 
responses can possibly result in nitrogen tissue supersaturation and 
nitrogen off-gassing, possibly to the point of deleterious vascular 
bubble formation (Jepson et al., 2003). Although hypothetical, 
discussions surrounding this potential process are controversial.
    Foraging--Disruption of feeding behavior can be difficult to 
correlate with anthropogenic sound exposure, so it is usually inferred 
by observed displacement from known foraging areas, the appearance of 
secondary indicators (e.g., bubble nets or sediment plumes), or changes 
in dive behavior. Noise from seismic surveys was not found to impact 
the feeding behavior in western grey whales off the coast of Russia 
(Yazvenko et al., 2007) and sperm whales engaged in foraging dives did 
not abandon dives when exposed to distant signatures of seismic airguns 
(Madsen et al., 2006). However, Miller et al. (2009) reported buzz 
rates (a proxy for feeding) 19 percent lower during exposure to distant 
signatures of seismic airguns. Balaenopterid whales exposed to moderate 
low-frequency signals similar to the ATOC sound source demonstrated no 
variation in foraging activity (Croll et al., 2001), whereas five out 
of six North Atlantic right whales exposed to an acoustic alarm 
interrupted their foraging dives (Nowacek et al., 2004). Although the 
received sound pressure levels were similar in the latter two studies, 
the frequency, duration, and temporal pattern of signal presentation 
were different. These factors, as well as differences in species 
sensitivity, are likely contributing factors to the differential 
response. Blue whales exposed to simulated mid-frequency sonar in the 
Southern California Bight were less likely to produce low frequency 
calls usually associated with feeding behavior (Melc[oacute]n et al., 
2012). However, Melc[oacute]n et al. (2012) were unable to determine if 
suppression of low frequency calls reflected a change

[[Page 46122]]

in their feeding performance or abandonment of foraging behavior and 
indicated that implications of the documented responses are unknown. 
Further, it is not known whether the lower rates of calling actually 
indicated a reduction in feeding behavior or social contact since the 
study used data from remotely deployed, passive acoustic monitoring 
buoys. In contrast, blue whales increased their likelihood of calling 
when ship noise was present, and decreased their likelihood of calling 
in the presence of explosive noise, although this result was not 
statistically significant (Melc[oacute]n et al., 2012). Additionally, 
the likelihood of an animal calling decreased with the increased 
received level of mid-frequency sonar, beginning at a SPL of 
approximately 110-120 dB re 1 [mu]Pa (Melc[oacute]n et al., 2012). 
Preliminary results from the 2010-2011 field season of an ongoing 
behavioral response study in Southern California waters indicated that, 
in some cases and at low received levels, tagged blue whales responded 
to mid-frequency sonar but that those responses were mild and there was 
a quick return to their baseline activity (Southall et al., 2011). A 
determination of whether foraging disruptions incur fitness 
consequences will require information on or estimates of the energetic 
requirements of the individuals and the relationship between prey 
availability, foraging effort and success, and the life history stage 
of the animal. Goldbogen et al., (2013) monitored behavioral responses 
of tagged blue whales located in feeding areas when exposed simulated 
MFA sonar. Responses varied depending on behavioral context, with deep 
feeding whales being more significantly affected (i.e., generalized 
avoidance; cessation of feeding; increased swimming speeds; or directed 
travel away from the source) compared to surface feeding individuals 
that typically showed no change in behavior. Non-feeding whales also 
seemed to be affected by exposure. The authors indicate that disruption 
of feeding and displacement could impact individual fitness and health. 
However, for this to be true, we would have to assume that an 
individual whale could not compensate for this lost feeding opportunity 
by either immediately feeding at another location, by feeding shortly 
after cessation of acoustic exposure, or by feeding at a later time. 
There is no indication this is the case, particularly since unconsumed 
prey would likely still be available in the environment in most cases 
following the cessation of acoustic exposure.
    Breathing--Variations in respiration naturally vary with different 
behaviors and variations in respiration rate as a function of acoustic 
exposure can be expected to co-occur with other behavioral reactions, 
such as a flight response or an alteration in diving. However, 
respiration rates in and of themselves may be representative of 
annoyance or an acute stress response. Mean exhalation rates of gray 
whales at rest and while diving were found to be unaffected by seismic 
surveys conducted adjacent to the whale feeding grounds (Gailey et al., 
2007). Studies with captive harbor porpoises showed increased 
respiration rates upon introduction of acoustic alarms (Kastelein et 
al., 2001; Kastelein et al., 2006a) and emissions for underwater data 
transmission (Kastelein et al., 2005). However, exposure of the same 
acoustic alarm to a striped dolphin under the same conditions did not 
elicit a response (Kastelein et al., 2006a), again highlighting the 
importance in understanding species differences in the tolerance of 
underwater noise when determining the potential for impacts resulting 
from anthropogenic sound exposure (Southall et al., 2007; Henderson et 
al., 2014).
    Social Relationships--Social interactions between mammals can be 
affected by noise via the disruption of communication signals or by the 
displacement of individuals. Disruption of social relationships 
therefore depends on the disruption of other behaviors (e.g., caused 
avoidance, masking, etc.) and no specific overview is provided here. 
However, social disruptions must be considered in context of the 
relationships that are affected. Long-term disruptions of mother/calf 
pairs or mating displays have the potential to affect the growth and 
survival or reproductive effort/success of individuals, respectively.
    Vocalizations (also see Masking Section)--Vocal changes in response 
to anthropogenic noise can occur across the repertoire of sound 
production modes used by marine mammals, such as whistling, 
echolocation click production, calling, and singing. Changes may result 
in response to a need to compete with an increase in background noise 
or may reflect an increased vigilance or startle response. For example, 
in the presence of low-frequency active sonar, humpback whales have 
been observed to increase the length of their ``songs'' (Miller et al., 
2000; Fristrup et al., 2003), possibly due to the overlap in 
frequencies between the whale song and the low-frequency active sonar. 
A similar compensatory effect for the presence of low-frequency vessel 
noise has been suggested for right whales; right whales have been 
observed to shift the frequency content of their calls upward while 
reducing the rate of calling in areas of increased anthropogenic noise 
(Parks et al., 2007). Killer whales off the northwestern coast of the 
U.S. have been observed to increase the duration of primary calls once 
a threshold in observing vessel density (e.g., whale watching) was 
reached, which has been suggested as a response to increased masking 
noise produced by the vessels (Foote et al., 2004; NOAA, 2014b). In 
contrast, both sperm and pilot whales potentially ceased sound 
production during the Heard Island feasibility test (Bowles et al., 
1994), although it cannot be absolutely determined whether the 
inability to acoustically detect the animals was due to the cessation 
of sound production or the displacement of animals from the area.
    Avoidance--Avoidance is the displacement of an individual from an 
area as a result of the presence of a sound. Richardson et al., (1995) 
noted that avoidance reactions are the most obvious manifestations of 
disturbance in marine mammals. It is qualitatively different from the 
flight response, but also differs in the magnitude of the response 
(i.e., directed movement, rate of travel, etc.). Oftentimes avoidance 
is temporary, and animals return to the area once the noise has ceased. 
Longer term displacement is possible, however, which can lead to 
changes in abundance or distribution patterns of the species in the 
affected region if they do not become acclimated to the presence of the 
sound (Blackwell et al., 2004; Bejder et al., 2006; Teilmann et al., 
2006). Acute avoidance responses have been observed in captive 
porpoises and pinnipeds exposed to a number of different sound sources 
(Kastelein et al., 2001; Finneran et al., 2003; Kastelein et al., 
2006a; Kastelein et al., 2006b). Short-term avoidance of seismic 
surveys, low frequency emissions, and acoustic deterrents have also 
been noted in wild populations of odontocetes (Bowles et al., 1994; 
Goold, 1996; 1998; Stone et al., 2000; Morton and Symonds, 2002) and to 
some extent in mysticetes (Gailey et al., 2007), while longer term or 
repetitive/chronic displacement for some dolphin groups and for 
manatees has been suggested to be due to the presence of chronic vessel 
noise (Haviland-Howell et al., 2007; Miksis-Olds et al., 2007).
    Maybaum (1993) conducted sound playback experiments to assess the 
effects of MFAS on humpback whales in Hawaiian waters. Specifically, 
she exposed focal pods to sounds of a 3.3-

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kHz sonar pulse, a sonar frequency sweep from 3.1 to 3.6 kHz, and a 
control (blank) tape while monitoring behavior, movement, and 
underwater vocalizations. The two types of sonar signals (which both 
contained mid- and low-frequency components) differed in their effects 
on the humpback whales, but both resulted in avoidance behavior. The 
whales responded to the pulse by increasing their distance from the 
sound source and responded to the frequency sweep by increasing their 
swimming speeds and track linearity. In the Caribbean, sperm whales 
avoided exposure to mid-frequency submarine sonar pulses, in the range 
of 1000 Hz to 10,000 Hz (IWC 2005).
    Kvadsheim et al., (2007) conducted a controlled exposure experiment 
in which killer whales fitted with D-tags were exposed to mid-frequency 
active sonar (Source A: A 1.0 second upsweep 209 dB @1-2 kHz every 10 
seconds for 10 minutes; Source B: With a 1.0 second upsweep 197 dB @6-7 
kHz every 10 seconds for 10 minutes). When exposed to Source A, a 
tagged whale and the group it was traveling with did not appear to 
avoid the source. When exposed to Source B, the tagged whales along 
with other whales that had been carousel feeding, ceased feeding during 
the approach of the sonar and moved rapidly away from the source. When 
exposed to Source B, Kvadsheim and his co-workers reported that a 
tagged killer whale seemed to try to avoid further exposure to the 
sound field by the following behaviors: Immediately swimming away 
(horizontally) from the source of the sound; engaging in a series of 
erratic and frequently deep dives that seemed to take it below the 
sound field; or swimming away while engaged in a series of erratic and 
frequently deep dives. Although the sample sizes in this study are too 
small to support statistical analysis, the behavioral responses of the 
orcas were consistent with the results of other studies.
    In 2007, the first in a series of behavioral response studies, a 
collaboration by the Navy, NMFS, and other scientists showed one beaked 
whale (Mesoplodon densirostris) responding to an MFAS playback. Tyack 
et al. (2011) indicates that the playback began when the tagged beaked 
whale was vocalizing at depth (at the deepest part of a typical feeding 
dive), following a previous control with no sound exposure. The whale 
appeared to stop clicking significantly earlier than usual, when 
exposed to mid-frequency signals in the 130-140 dB (rms) received level 
range. After a few more minutes of the playback, when the received 
level reached a maximum of 140-150 dB, the whale ascended on the slow 
side of normal ascent rates with a longer than normal ascent, at which 
point the exposure was terminated. The results are from a single 
experiment and a greater sample size is needed before robust and 
definitive conclusions can be drawn.
    Tyack et al. (2011) also indicates that Blainville's beaked whales 
appear to be sensitive to noise at levels well below expected TTS (~160 
dB re1[mu]Pa). This sensitivity is manifest by an adaptive movement 
away from a sound source. This response was observed irrespective of 
whether the signal transmitted was within the band width of MFAS, which 
suggests that beaked whales may not respond to the specific sound 
signatures. Instead, they may be sensitive to any pulsed sound from a 
point source in this frequency range. The response to such stimuli 
appears to involve maximizing the distance from the sound source.
    Stimpert et al. (2014) tagged a Baird's beaked whale, which was 
subsequently exposed to simulated mid-frequency sonar. Received levels 
of sonar on the tag increased to a maximum of 138 dB re 1[mu]Pa, which 
occurred during the first exposure dive. Some sonar received levels 
could not be measured due to flow noise and surface noise on the tag.
    Results from a 2007-2008 study conducted near the Bahamas showed a 
change in diving behavior of an adult Blainville's beaked whale to 
playback of mid-frequency source and predator sounds (Boyd et al., 
2008; Southall et al. 2009; Tyack et al., 2011). Reaction to mid-
frequency sounds included premature cessation of clicking and 
termination of a foraging dive, and a slower ascent rate to the 
surface. Results from a similar behavioral response study in southern 
California waters have been presented for the 2010-2011 field season 
(Southall et al. 2011; DeRuiter et al., 2013b). DeRuiter et al. (2013b) 
presented results from two Cuvier's beaked whales that were tagged and 
exposed to simulated mid-frequency active sonar during the 2010 and 
2011 field seasons of the southern California behavioral response 
study. The 2011 whale was also incidentally exposed to mid-frequency 
active sonar from a distant naval exercise. Received levels from the 
mid-frequency active sonar signals from the controlled and incidental 
exposures were calculated as 84-144 and 78-106 dB re 1 [mu]Pa root mean 
square (rms), respectively. Both whales showed responses to the 
controlled exposures, ranging from initial orientation changes to 
avoidance responses characterized by energetic fluking and swimming 
away from the source. However, the authors did not detect similar 
responses to incidental exposure to distant naval sonar exercises at 
comparable received levels, indicating that context of the exposures 
(e.g., source proximity, controlled source ramp-up) may have been a 
significant factor. Cuvier's beaked whale responses suggested 
particular sensitivity to sound exposure as consistent with results for 
Blainville's beaked whale. Similarly, beaked whales exposed to sonar 
during British training exercises stopped foraging (DSTL, 2007), and 
preliminary results of controlled playback of sonar may indicate 
feeding/foraging disruption of killer whales and sperm whales (Miller 
et al., 2011).
    In the 2007-2008 Bahamas study, playback sounds of a potential 
predator--a killer whale--resulted in a similar but more pronounced 
reaction, which included longer inter-dive intervals and a sustained 
straight-line departure of more than 20 km from the area. The authors 
noted, however, that the magnified reaction to the predator sounds 
could represent a cumulative effect of exposure to the two sound types 
since killer whale playback began approximately 2 hours after mid-
frequency source playback. Pilot whales and killer whales off Norway 
also exhibited horizontal avoidance of a transducer with outputs in the 
mid-frequency range (signals in the 1-2 kHz and 6-7 kHz ranges) (Miller 
et al., 2011). Additionally, separation of a calf from its group during 
exposure to mid-frequency sonar playback was observed on one occasion 
(Miller et al., 2011). In contrast, preliminary analyses suggest that 
none of the pilot whales or false killer whales in the Bahamas showed 
an avoidance response to controlled exposure playbacks (Southall et 
al., 2009).
    Through analysis of the behavioral response studies, a preliminary 
overarching effect of greater sensitivity to all anthropogenic 
exposures was seen in beaked whales compared to the other odontocetes 
studied (Southall et al., 2009). Therefore, recent studies have focused 
specifically on beaked whale responses to active sonar transmissions or 
controlled exposure playback of simulated sonar on various military 
ranges (Defence Science and Technology Laboratory, 2007; Claridge and 
Durban, 2009; Moretti et al., 2009; McCarthy et al., 2011; Tyack et 
al., 2011). In the Bahamas, Blainville's beaked whales located on the 
range will move off-range during sonar use and return only after the 
sonar transmissions have stopped, sometimes taking several days to do 
so (Claridge and Durban

[[Page 46124]]

2009; Moretti et al., 2009; McCarthy et al., 2011; Tyack et al., 2011). 
Moretti et al. (2014) used recordings from seafloor-mounted hydrophones 
at the Atlantic Undersea Test and Evaluation Center (AUTEC) to analyze 
the probability of Blainsville's beaked whale dives before, during, and 
after Navy sonar exercises.
    Orientation--A shift in an animal's resting state or an attentional 
change via an orienting response represent behaviors that would be 
considered mild disruptions if occurring alone. As previously 
mentioned, the responses may co-occur with other behaviors; for 
instance, an animal may initially orient toward a sound source, and 
then move away from it. Thus, any orienting response should be 
considered in context of other reactions that may occur.
    There are few empirical studies of avoidance responses of free-
living cetaceans to MFAS. Much more information is available on the 
avoidance responses of free-living cetaceans to other acoustic sources, 
such as seismic airguns and low-frequency tactical sonar, than MFAS.

Behavioral Responses

    Southall et al. (2007) reports the results of the efforts of a 
panel of experts in acoustic research from behavioral, physiological, 
and physical disciplines that convened and reviewed the available 
literature on marine mammal hearing and physiological and behavioral 
responses to human-made sound with the goal of proposing exposure 
criteria for certain effects. This peer-reviewed compilation of 
literature is very valuable, though Southall et al. (2007) note that 
not all data are equal, some have poor statistical power, insufficient 
controls, and/or limited information on received levels, background 
noise, and other potentially important contextual variables--such data 
were reviewed and sometimes used for qualitative illustration but were 
not included in the quantitative analysis for the criteria 
recommendations. All of the studies considered, however, contain an 
estimate of the received sound level when the animal exhibited the 
indicated response.
    In the Southall et al. (2007) publication, for the purposes of 
analyzing responses of marine mammals to anthropogenic sound and 
developing criteria, the authors differentiate between single pulse 
sounds, multiple pulse sounds, and non-pulse sounds. MFAS/HFAS sonar is 
considered a non-pulse sound. Southall et al. (2007) summarize the 
studies associated with low-frequency, mid-frequency, and high-
frequency cetacean and pinniped responses to non-pulse sounds, based 
strictly on received level, in Appendix C of their article 
(incorporated by reference and summarized in the three paragraphs 
below).
    The studies that address responses of low-frequency cetaceans to 
non-pulse sounds include data gathered in the field and related to 
several types of sound sources (of varying similarity to MFAS/HFAS) 
including: Vessel noise, drilling and machinery playback, low-frequency 
M-sequences (sine wave with multiple phase reversals) playback, 
tactical low-frequency active sonar playback, drill ships, Acoustic 
Thermometry of Ocean Climate (ATOC) source, and non-pulse playbacks. 
These studies generally indicate no (or very limited) responses to 
received levels in the 90 to 120 dB re: 1 [mu]Pa range and an 
increasing likelihood of avoidance and other behavioral effects in the 
120 to 160 dB range. As mentioned earlier, though, contextual variables 
play a very important role in the reported responses and the severity 
of effects are not linear when compared to received level. Also, few of 
the laboratory or field datasets had common conditions, behavioral 
contexts, or sound sources, so it is not surprising that responses 
differ.
    The studies that address responses of mid-frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: Pingers, drilling playbacks, ship 
and ice-breaking noise, Vessel noise, Acoustic Harassment Devices 
(AHDs), Acoustic Deterrent Devices (ADDs), MFAS, and non-pulse bands 
and tones. Southall et al. (2007) were unable to come to a clear 
conclusion regarding the results of these studies. In some cases, 
animals in the field showed significant responses to received levels 
between 90 and 120 dB, while in other cases these responses were not 
seen in the 120 to 150 dB range. The disparity in results was likely 
due to contextual variation and the differences between the results in 
the field and laboratory data (animals typically responded at lower 
levels in the field).
    The studies that address responses of high frequency cetaceans to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: Pingers, AHDs, and various 
laboratory non-pulse sounds. All of these data were collected from 
harbor porpoises. Southall et al. (2007) concluded that the existing 
data indicate that harbor porpoises are likely sensitive to a wide 
range of anthropogenic sounds at low received levels (~ 90 to 120 dB), 
at least for initial exposures. All recorded exposures above 140 dB 
induced profound and sustained avoidance behavior in wild harbor 
porpoises (Southall et al., 2007). Rapid habituation was noted in some 
but not all studies. There is no data to indicate whether other high 
frequency cetaceans are as sensitive to anthropogenic sound as harbor 
porpoises are.
    The studies that address the responses of pinnipeds in water to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to MFAS/HFAS) including: AHDs, ATOC, various non-pulse 
sounds used in underwater data communication; underwater drilling, and 
construction noise. Few studies exist with enough information to 
include them in the analysis. The limited data suggested that exposures 
to non-pulse sounds between 90 and 140 dB generally do not result in 
strong behavioral responses in pinnipeds in water, but no data exist at 
higher received levels.

Potential Effects of Behavioral Disturbance

    The different ways that marine mammals respond to sound are 
sometimes indicators of the ultimate effect that exposure to a given 
stimulus will have on the well-being (survival, reproduction, etc.) of 
an animal. There is limited marine mammal data quantitatively relating 
the exposure of marine mammals to sound to effects on reproduction or 
survival, though data exists for terrestrial species to which we can 
draw comparisons for marine mammals.
    Attention is the cognitive process of selectively concentrating on 
one aspect of an animal's environment while ignoring other things 
(Posner, 1994). Because animals (including humans) have limited 
cognitive resources, there is a limit to how much sensory information 
they can process at any time. The phenomenon called ``attentional 
capture'' occurs when a stimulus (usually a stimulus that an animal is 
not concentrating on or attending to) ``captures'' an animal's 
attention. This shift in attention can occur consciously or 
subconsciously (for example, when an animal hears sounds that it 
associates with the approach of a predator) and the shift in attention 
can be sudden (Dukas, 2002; van Rij, 2007). Once a stimulus has 
captured an animal's attention, the animal can respond by ignoring the 
stimulus, assuming a ``watch and wait''

[[Page 46125]]

posture, or treat the stimulus as a disturbance and respond 
accordingly, which includes scanning for the source of the stimulus or 
``vigilance'' (Cowlishaw et al., 2004).
    Vigilance is normally an adaptive behavior that helps animals 
determine the presence or absence of predators, assess their distance 
from conspecifics, or to attend cues from prey (Bednekoff and Lima, 
1998; Treves, 2000). Despite those benefits, however, vigilance has a 
cost of time; when animals focus their attention on specific 
environmental cues, they are not attending to other activities such as 
foraging. These costs have been documented best in foraging animals, 
where vigilance has been shown to substantially reduce feeding rates 
(Saino, 1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002). 
Animals will spend more time being vigilant, which may translate to 
less time foraging or resting, when disturbance stimuli approach them 
more directly, remain at closer distances, have a greater group size 
(for example, multiple surface vessels), or when they co-occur with 
times that an animal perceives increased risk (for example, when they 
are giving birth or accompanied by a calf). Most of the published 
literature, however, suggests that direct approaches will increase the 
amount of time animals will dedicate to being vigilant. For example, 
bighorn sheep and Dall's sheep dedicated more time being vigilant, and 
less time resting or foraging, when aircraft made direct approaches 
over them (Frid, 2001; Stockwell et al., 1991).
    Several authors have established that long-term and intense 
disturbance stimuli can cause population declines by reducing the body 
condition of individuals that have been disturbed, followed by reduced 
reproductive success, reduced survival, or both (Daan et al., 1996; 
Madsen, 1994; White, 1983). For example, Madsen (1994) reported that 
pink-footed geese in undisturbed habitat gained body mass and had about 
a 46-percent reproductive success rate compared with geese in disturbed 
habitat (being consistently scared off the fields on which they were 
foraging) which did not gain mass and had a 17-percent reproductive 
success rate. Similar reductions in reproductive success have been 
reported for mule deer disturbed by all-terrain vehicles (Yarmoloy et 
al., 1988), caribou disturbed by seismic exploration blasts (Bradshaw 
et al., 1998), caribou disturbed by low-elevation military jet-fights 
(Luick et al., 1996), and caribou disturbed by low-elevation jet 
flights (Harrington and Veitch, 1992). Similarly, a study of elk that 
were disturbed experimentally by pedestrians concluded that the ratio 
of young to mothers was inversely related to disturbance rate (Phillips 
and Alldredge, 2000).
    The primary mechanism by which increased vigilance and disturbance 
appear to affect the fitness of individual animals is by disrupting an 
animal's time budget and, as a result, reducing the time they might 
spend foraging and resting (which increases an animal's activity rate 
and energy demand). For example, a study of grizzly bears reported that 
bears disturbed by hikers reduced their energy intake by an average of 
12 kcal/minute (50.2 x 10\3\kJ/minute), and spent energy fleeing or 
acting aggressively toward hikers (White et al., 1999). Alternately, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a 5-day period did not cause any sleep 
deprivation or stress effects such as changes in cortisol or 
epinephrine levels.
    Lusseau and Bejder (2007) present data from three long-term studies 
illustrating the connections between disturbance from whale-watching 
boats and population-level effects in cetaceans. In Sharks Bay 
Australia, the abundance of bottlenose dolphins was compared within 
adjacent control and tourism sites over three consecutive 4.5-year 
periods of increasing tourism levels. Between the second and third time 
periods, in which tourism doubled, dolphin abundance decreased by 15 
percent in the tourism area and did not change significantly in the 
control area. In Fiordland, New Zealand, two populations (Milford and 
Doubtful Sounds) of bottlenose dolphins with tourism levels that 
differed by a factor of seven were observed and significant increases 
in travelling time and decreases in resting time were documented for 
both. Consistent short-term avoidance strategies were observed in 
response to tour boats until a threshold of disturbance was reached 
(average 68 minutes between interactions), after which the response 
switched to a longer term habitat displacement strategy. For one 
population tourism only occurred in a part of the home range, however, 
tourism occurred throughout the home range of the Doubtful Sound 
population and once boat traffic increased beyond the 68-minute 
threshold (resulting in abandonment of their home range/preferred 
habitat), reproductive success drastically decreased (increased 
stillbirths) and abundance decreased significantly (from 67 to 56 
individuals in short period). Last, in a study of northern resident 
killer whales off Vancouver Island, exposure to boat traffic was shown 
to reduce foraging opportunities and increase traveling time. A simple 
bioenergetics model was applied to show that the reduced foraging 
opportunities equated to a decreased energy intake of 18 percent, while 
the increased traveling incurred an increased energy output of 3-4 
percent, which suggests that a management action based on avoiding 
interference with foraging might be particularly effective.
    On a related note, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (24-hour 
cycle). Substantive 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). Consequently, a behavioral response lasting less than 1 day and 
not recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multiple-day 
substantive behavioral reactions and multiple-day anthropogenic 
activities. For example, just because an at-sea exercise lasts for 
multiple days does not necessarily mean that individual animals are 
either exposed to that exercise for multiple days or, further, exposed 
in a manner resulting in a sustained multiple day substantive 
behavioral responses.
    In order to understand how the effects of activities may or may not 
impact stocks and populations of marine mammals, it is necessary to 
understand not only what the likely disturbances are going to be, but 
how those disturbances may affect the reproductive success and 
survivorship of individuals, and then how those impacts to individuals 
translate to population changes. Following on the earlier work of a 
committee of the U.S. National Research Council (NRC, 2005), New et al. 
(2014), in an effort termed the Potential Consequences of Disturbance 
(PCoD), outline an updated conceptual model of the relationships 
linking disturbance to changes in behavior and physiology, health, 
vital rates, and population dynamics (below). As depicted, behavioral 
and physiological changes can either have direct (acute) effects on 
vital rates, such as when changes in habitat use or increased stress 
levels raise the probability of mother-calf separation or predation, or 
they can have indirect and long-term (chronic) effects on vital rates, 
such as when changes in time/energy budgets or

[[Page 46126]]

increased disease susceptibility affect health, which then affects 
vital rates (New et al., 2014). In addition to outlining this general 
framework and compiling the relevant literature that supports it, New 
et al. (2014) have chosen four example species for which extensive 
long-term monitoring data exist (southern elephant seals, North 
Atlantic right whales, Ziphidae beaked whales, and bottlenose dolphins) 
and developed state-space energetic models that can be used to 
effectively forecast longer-term, population-level impacts from 
behavioral changes. While these are very specific models with very 
specific data requirements that cannot yet be applied broadly to 
project-specific risk assessments, they are a critical first step.
    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. Since preparation of the 
proposed rule, NMFS has considered additional studies regarding 
behavioral responses that are relevant to the proposed activities and 
energy sources. A recent study by Moore and Barlow (2013) 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. In addition, Houser et 
al., 2013 and Claridge, 2013 were recently published.
    Houser et al. (2013) performed a controlled exposure study 
involving California sea lions exposed to a simulated mid-frequency 
sonar signal. The purpose of this Navy-sponsored study was to determine 
the probability and magnitude of behavioral responses by California sea 
lions exposed to differing intensities of simulated mid-frequency sonar 
signals. Houser et al.'s findings are consistent with current 
scientific studies and criteria development concerning marine mammal 
reactions to mid-frequency sonar sounds.
    Claridge's (2013) Ph.D. thesis investigated the potential effects 
exposure to mid-frequency active sonar could have on beaked whale 
demographics. In summary, Claridge suggested that lower reproductive 
rates observed at the Navy's Atlantic Undersea Test and Evaluation 
Center (AUTEC), when compared to a control site, were due to stressors 
associated with frequent and repeated use of Navy sonar. However, the 
author noted that there may be other unknown differences between the 
sites. It is also important to note that there were some relevant 
shortcomings of this study. For example, all of the re-sighted whales 
during the 5-year study at both sites were female, which Claridge 
acknowledged can lead to a negative bias in the abundance estimation. 
There was also a reduced effort and shorter overall study period at the 
AUTEC site that failed to capture some of the emigration/immigration 
trends identified at the control site. Furthermore, Claridge assumed 
that the two sites were identical and therefore should have equal 
potential abundances; when in reality, there were notable physical 
differences. All of the aforementioned studies were considered in NMFS' 
determination to issue regulations and associated LOA to the Navy for 
their proposed activities in the MITT Study Area.

Stranding and Mortality

    When a live or dead marine mammal swims or floats onto shore and 
becomes ``beached'' or incapable of returning to sea, the event is 
termed a ``stranding'' (Geraci et al., 1999; Perrin and Geraci, 2002; 
Geraci and Lounsbury, 2005; NMFS, 2007). The legal definition for a 
stranding within the U.S. is that (A) ``a marine mammal is dead and is 
(i) on a beach or shore of the United States; or (ii) in waters under 
the jurisdiction of the United States (including any navigable waters); 
or (B) a marine mammal is alive and is (i) on a beach or shore of the 
United States and unable to return to the water; (ii) on a beach or 
shore of the United States and, although able to return to the water, 
is in need of apparent medical attention; or (iii) in the waters under 
the jurisdiction of the United States (including any navigable waters), 
but is unable to return to its natural habitat under its own power or 
without assistance.'' (16 U.S.C. 1421h).
    Marine mammals are known to strand for a variety of reasons, such 
as infectious agents, biotoxicosis, starvation, fishery interaction, 
ship strike, unusual oceanographic or weather events, sound exposure, 
or combinations of these stressors sustained concurrently or in series. 
However, the cause or causes of most strandings are unknown (Geraci et 
al., 1976; Eaton, 1979, Odell et al., 1980; Best, 1982). Numerous 
studies suggest that the physiology, behavior, habitat relationships, 
age, or condition of cetaceans may cause them to strand or might pre-
dispose them to strand when exposed to another phenomenon. These 
suggestions are consistent with the conclusions of numerous other 
studies that have demonstrated that combinations of dissimilar 
stressors commonly combine to kill an animal or dramatically reduce its 
fitness, even though one exposure without the other does not produce 
the same result (Chroussos, 2000; Creel, 2005; DeVries et al., 2003; 
Fair and Becker, 2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a; 
2005b, Romero, 2004; Sih et al., 2004). For reference, between 2001 and 
2009, there was an annual average of 1,400 cetacean strandings and 
4,300 pinniped strandings along the coasts of the continental U.S. and 
Alaska (NMFS, 2011).
    Several sources have published lists of mass stranding events of 
cetaceans in an attempt to identify relationships between those 
stranding events and military sonar (Hildebrand, 2004; IWC, 2005; 
Taylor et al., 2004). For example, based on a review of stranding 
records between 1960 and 1995, the International Whaling Commission 
(2005) identified ten mass stranding events of Cuvier's beaked whales 
had been reported and one mass stranding of four Baird's beaked whale. 
The IWC concluded that, out of eight stranding events reported from the 
mid-1980s to the summer of 2003, seven had been coincident with the use 
of tactical mid-frequency sonar, one of those seven had been associated 
with the use of tactical low-frequency sonar, and the remaining 
stranding event had been associated with the use of seismic airguns.
    Most of the stranding events reviewed by the International Whaling 
Commission involved beaked whales. A mass stranding of Cuvier's beaked 
whales in the eastern Mediterranean Sea occurred in 1996 (Frantzis, 
1998) and mass stranding events involving Gervais' beaked whales, 
Blainville's beaked whales, and Cuvier's beaked whales occurred off the 
coast of the Canary Islands in the late 1980s (Simmonds and Lopez-
Jurado, 1991). The stranding events that occurred in the Canary Islands 
and Kyparissiakos Gulf in the late 1990s and the Bahamas in 2000 have 
been the most intensively-studied mass stranding events and have been 
associated with naval maneuvers involving the use of tactical sonar.
    Between 1960 and 2006, 48 strandings (68 percent) involved beaked 
whales, three (4 percent) involved dolphins, and 14 (20 percent) 
involved whale species. Cuvier's beaked whales were involved in the 
greatest number of these events (48 or 68 percent), followed by sperm 
whales (seven or 10 percent), and Blainville's and Gervais' beaked 
whales (four each or 6 percent). Naval activities (not just activities 
conducted by the U.S. Navy) that might have involved active sonar are 
reported to have coincided with nine or 10 (13 to 14 percent) of

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those stranding events. Between the mid-1980s and 2003 (the period 
reported by the International Whaling Commission), NMFS identified 
reports of 44 mass cetacean stranding events of which at least seven 
were coincident with naval exercises that were using MFAS.

Strandings Associated With Impulse Sound

    During a Navy training event on March 4, 2011, at the Silver Strand 
Training Complex in San Diego, California, three or possibly four 
dolphins were killed in an explosion. During an underwater detonation 
training event, a pod of 100 to 150 long-beaked common dolphins were 
observed moving towards the 700-yd (640.1-m) exclusion zone around the 
explosive charge, monitored by personnel in a safety boat and 
participants in a dive boat. Approximately 5 minutes remained on a 
time-delay fuse connected to a single 8.76 lb (3.97 kg) explosive 
charge (C-4 and detonation cord). Although the dive boat was placed 
between the pod and the explosive in an effort to guide the dolphins 
away from the area, that effort was unsuccessful and three long-beaked 
common dolphins near the explosion died. In addition to the three 
dolphins found dead on March 4, the remains of a fourth dolphin were 
discovered on March 7, 2011 near Ocean Beach, California (3 days later 
and approximately 11.8 mi. [19 km] from Silver Strand where the 
training event occurred), which might also have been related to this 
event. Association of the fourth stranding with the training event is 
uncertain because dolphins strand on a regular basis in the San Diego 
area. Details such as the dolphins' depth and distance from the 
explosive at the time of the detonation could not be estimated from the 
250 yd (228.6 m) standoff point of the observers in the dive boat or 
the safety boat.
    These dolphin mortalities are the only known occurrence of a U.S. 
Navy training or testing event involving impulse energy (underwater 
detonation) that caused mortality or injury to a marine mammal. Despite 
this being a rare occurrence, the Navy has reviewed training 
requirements, safety procedures, and possible mitigation measures and 
implemented changes to reduce the potential for this to occur in the 
future. Discussions of procedures associated with these and other 
training and testing events are presented in the Mitigation section.

Strandings Associated With MFAS

    Over the past 16 years, there have been five stranding events 
coincident with military mid-frequency sonar use in which exposure to 
sonar is believed to have been a contributing factor: Greece (1996); 
the Bahamas (2000); Madeira (2000); Canary Islands (2002); and Spain 
(2006). Additionally, in 2004, during the Rim of the Pacific (RIMPAC) 
exercises, between 150 and 200 usually pelagic melon-headed whales 
occupied the shallow waters of Hanalei Bay, Kauai, Hawaii for over 28 
hours. NMFS determined that MFAS was a plausible, if not likely, 
contributing factor in what may have been a confluence of events that 
led to the stranding. A number of other stranding events coincident 
with the operation of mid-frequency sonar, including the death of 
beaked whales or other species (minke whales, dwarf sperm whales, pilot 
whales), have been reported; however, the majority have not been 
investigated to the degree necessary to determine the cause of the 
stranding and only one of these stranding events, the Bahamas (2000), 
was associated with exercises conducted by the U.S. Navy. Most 
recently, the Independent Scientific Review Panel investigating 
potential contributing factors to a 2008 mass stranding of melon-headed 
whales in Antsohihy, Madagascar released its final report suggesting 
that the stranding was likely initially triggered by an industry 
seismic survey. This report suggests that the operation of a commercial 
high-powered 12 kHz multi-beam echosounder during an industry seismic 
survey was a plausible and likely initial 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. The report indicates that the risk of 
this particular convergence of factors and ultimate outcome is likely 
very low, but recommends that the potential be considered in 
environmental planning. Because of the association between tactical 
mid-frequency active sonar use and a small number of marine mammal 
strandings, the Navy and NMFS have been considering and addressing the 
potential for strandings in association with Navy activities for years. 
In addition to a suite of mitigation intended to more broadly minimize 
impacts to marine mammals, the Navy and NMFS have a detailed Stranding 
Response Plan that outlines reporting, communication, and response 
protocols intended both to minimize the impacts of, and enhance the 
analysis of, any potential stranding in areas where the Navy operates.
    Greece (1996)--Twelve Cuvier's beaked whales stranded atypically 
(in both time and space) along a 38.2-km strand of the Kyparissiakos 
Gulf coast on May 12 and 13, 1996 (Frantzis, 1998). From May 11 through 
May 15, the North Atlantic Treaty Organization (NATO) research vessel 
Alliance was conducting sonar tests with signals of 600 Hz and 3 kHz 
and source levels of 228 and 226 dB re: 1[mu]Pa, respectively (D'Amico 
and Verboom, 1998; D'Spain et al., 2006). The timing and location of 
the testing encompassed the time and location of the strandings 
(Frantzis, 1998).
    Necropsies of eight of the animals were performed but were limited 
to basic external examination and sampling of stomach contents, blood, 
and skin. No ears or organs were collected, and no histological samples 
were preserved. No apparent abnormalities or wounds were found. 
Examination of photos of the animals, taken soon after their death, 
revealed that the eyes of at least four of the individuals were 
bleeding. Photos were taken soon after their death (Frantzis, 2004). 
Stomach contents contained the flesh of cephalopods, indicating that 
feeding had recently taken place (Frantzis, 1998).
    All available information regarding the conditions associated with 
this stranding event were compiled, and many potential causes were 
examined including major pollution events, prominent tectonic activity, 
unusual physical or meteorological events, magnetic anomalies, 
epizootics, and conventional military activities (International Council 
for the Exploration of the Sea, 2005a). However, none of these 
potential causes coincided in time or space with the mass stranding, or 
could explain its characteristics (International Council for the 
Exploration of the Sea, 2005a). The robust condition of the animals, 
plus the recent stomach contents, is inconsistent with pathogenic 
causes. In addition, environmental causes can be ruled out as there 
were no unusual environmental circumstances or events before or during 
this time period and within the general proximity (Frantzis, 2004).
    Because of the rarity of this mass stranding of Cuvier's beaked 
whales in the Kyparissiakos Gulf (first one in history), the 
probability for the two events (the military exercises and the 
strandings) to coincide in time and location, while being independent 
of each other, was thought to be extremely low (Frantzis, 1998). 
However, because full necropsies had not been conducted,

[[Page 46128]]

and no abnormalities were noted, the cause of the strandings could not 
be precisely determined (Cox et al., 2006). A Bioacoustics Panel 
convened by NATO concluded that the evidence available did not allow 
them to accept or reject sonar exposures as a causal agent in these 
stranding events. The analysis of this stranding event provided support 
for, but no clear evidence for, the cause-and-effect relationship of 
tactical sonar training activities and beaked whale strandings (Cox et 
al., 2006).
    Bahamas (2000)--NMFS and the Navy prepared a joint report 
addressing the multi-species stranding in the Bahamas in 2000, which 
took place within 24 hours of U.S. Navy ships using MFAS as they passed 
through the Northeast and Northwest Providence Channels on March 15-16, 
2000. The ships, which operated both AN/SQS-53C and AN/SQS-56, moved 
through the channel while emitting sonar pings approximately every 24 
seconds. Of the 17 cetaceans that stranded over a 36-hr period 
(Cuvier's beaked whales, Blainville's beaked whales, minke whales, and 
a spotted dolphin), seven animals died on the beach (five Cuvier's 
beaked whales, one Blainville's beaked whale, and the spotted dolphin), 
while the other 10 were returned to the water alive (though their 
ultimate fate is unknown). As discussed in the Bahamas report (DOC/DON, 
2001), there is no likely association between the minke whale and 
spotted dolphin strandings and the operation of MFAS.
    Necropsies were performed on five of the stranded beaked whales. 
All five necropsied beaked whales were in good body condition, showing 
no signs of infection, disease, ship strike, blunt trauma, or fishery 
related injuries, and three still had food remains in their stomachs. 
Auditory structural damage was discovered in four of the whales, 
specifically bloody effusions or hemorrhaging around the ears. 
Bilateral intracochlear and unilateral temporal region subarachnoid 
hemorrhage, with blood clots in the lateral ventricles, were found in 
two of the whales. Three of the whales had small hemorrhages in their 
acoustic fats (located along the jaw and in the melon).
    A comprehensive investigation was conducted and all possible causes 
of the stranding event were considered, whether they seemed likely at 
the outset or not. Based on the way in which the strandings coincided 
with ongoing naval activity involving tactical MFAS use, in terms of 
both time and geography, the nature of the physiological effects 
experienced by the dead animals, and the absence of any other acoustic 
sources, the investigation team concluded that MFAS aboard U.S. Navy 
ships that were in use during the active sonar exercise in question 
were the most plausible source of this acoustic or impulse trauma to 
beaked whales. This sound source was active in a complex environment 
that included the presence of a surface duct, unusual and steep 
bathymetry, a constricted channel with limited egress, intensive use of 
multiple, active sonar units over an extended period of time, and the 
presence of beaked whales that appear to be sensitive to the 
frequencies produced by these active sonars. The investigation team 
concluded that the cause of this stranding event was the confluence of 
the Navy MFAS and these contributory factors working together, and 
further recommended that the Navy avoid operating MFAS in situations 
where these five factors would be likely to occur. This report does not 
conclude that all five of these factors must be present for a stranding 
to occur, nor that beaked whales are the only species that could 
potentially be affected by the confluence of the other factors. Based 
on this, NMFS believes that the operation of MFAS in situations where 
surface ducts exist, or in marine environments defined by steep 
bathymetry and/or constricted channels may increase the likelihood of 
producing a sound field with the potential to cause cetaceans 
(especially beaked whales) to strand, and therefore, suggests the need 
for increased vigilance while operating MFAS in these areas, especially 
when beaked whales (or potentially other deep divers) are likely 
present.
    Madeira, Spain (2000)--From May 10-14, 2000, three Cuvier's beaked 
whales were found atypically stranded on two islands in the Madeira 
archipelago, Portugal (Cox et al., 2006). A fourth animal was reported 
floating in the Madeiran waters by fisherman but did not come ashore 
(Woods Hole Oceanographic Institution, 2005). Joint NATO amphibious 
training peacekeeping exercises involving participants from 17 
countries and 80 warships, took place in Portugal during May 2-15, 
2000.
    The bodies of the three stranded whales were examined post mortem 
(Woods Hole Oceanographic Institution, 2005), though only one of the 
stranded whales was fresh enough (24 hours after stranding) to be 
necropsied (Cox et al., 2006). Results from the necropsy revealed 
evidence of hemorrhage and congestion in the right lung and both 
kidneys (Cox et al., 2006). There was also evidence of intercochlear 
and intracranial hemorrhage similar to that which was observed in the 
whales that stranded in the Bahamas event (Cox et al., 2006). There 
were no signs of blunt trauma, and no major fractures (Woods Hole 
Oceanographic Institution, 2005). The cranial sinuses and airways were 
found to be clear with little or no fluid deposition, which may 
indicate good preservation of tissues (Woods Hole Oceanographic 
Institution, 2005).
    Several observations on the Madeira stranded beaked whales, such as 
the pattern of injury to the auditory system, are the same as those 
observed in the Bahamas strandings. Blood in and around the eyes, 
kidney lesions, pleural hemorrhages, and congestion in the lungs are 
particularly consistent with the pathologies from the whales stranded 
in the Bahamas, and are consistent with stress and pressure related 
trauma. The similarities in pathology and stranding patterns between 
these two events suggest that a similar pressure event may have 
precipitated or contributed to the strandings at both sites (Woods Hole 
Oceanographic Institution, 2005).
    Even though no definitive causal link can be made between the 
stranding event and naval exercises, certain conditions may have 
existed in the exercise area that, in their aggregate, may have 
contributed to the marine mammal strandings (Freitas, 2004): exercises 
were conducted in areas of at least 547 fathoms (1,000 m) depth near a 
shoreline where there is a rapid change in bathymetry on the order of 
547 to 3,281 fathoms (1,000 to 6,000 m) occurring across a relatively 
short horizontal distance (Freitas, 2004); multiple ships were 
operating around Madeira, though it is not known if MFAS was used, and 
the specifics of the sound sources used are unknown (Cox et al., 2006, 
Freitas, 2004); and exercises took place in an area surrounded by 
landmasses separated by less than 35 nm (65 km) and at least 10 nm (19 
km) in length, or in an embayment. Exercises involving multiple ships 
employing MFAS near land may produce sound directed towards a channel 
or embayment that may cut off the lines of egress for marine mammals 
(Freitas, 2004).
    Canary Islands, Spain (2002)--The southeastern area within the 
Canary Islands is well known for aggregations of beaked whales due to 
its ocean depths of greater than 547 fathoms (1,000 m) within a few 
hundred meters of the coastline (Fernandez et al., 2005). On September 
24, 2002, 14 beaked whales were found stranded on Fuerteventura and 
Lanzarote Islands in the Canary Islands (International Council for 
Exploration of the Sea, 2005a). Seven whales died, while the

[[Page 46129]]

remaining seven live whales were returned to deeper waters (Fernandez 
et al., 2005). Four beaked whales were found stranded dead over the 
next three days either on the coast or floating offshore. These 
strandings occurred within near proximity of an international naval 
exercise that utilized MFAS and involved numerous surface warships and 
several submarines. Strandings began about 4 hours after the onset of 
MFAS activity (International Council for Exploration of the Sea, 2005a; 
Fernandez et al., 2005).
    Eight Cuvier's beaked whales, one Blainville's beaked whale, and 
one Gervais' beaked whale were necropsied, six of them within 12 hours 
of stranding (Fernandez et al., 2005). No pathogenic bacteria were 
isolated from the carcasses (Jepson et al., 2003). The animals 
displayed severe vascular congestion and hemorrhage especially around 
the tissues in the jaw, ears, brain, and kidneys, displaying marked 
disseminated microvascular hemorrhages associated with widespread fat 
emboli (Jepson et al., 2003; International Council for Exploration of 
the Sea, 2005a). Several organs contained intravascular bubbles, 
although definitive evidence of gas embolism in vivo is difficult to 
determine after death (Jepson et al., 2003). The livers of the 
necropsied animals were the most consistently affected organ, which 
contained macroscopic gas-filled cavities and had variable degrees of 
fibrotic encapsulation. In some animals, cavitary lesions had 
extensively replaced the normal tissue (Jepson et al., 2003). Stomachs 
contained a large amount of fresh and undigested contents, suggesting a 
rapid onset of disease and death (Fernandez et al., 2005). Head and 
neck lymph nodes were enlarged and congested, and parasites were found 
in the kidneys of all animals (Fernandez et al., 2005).
    The association of NATO MFAS use close in space and time to the 
beaked whale strandings, and the similarity between this stranding 
event and previous beaked whale mass strandings coincident with sonar 
use, suggests that a similar scenario and causative mechanism of 
stranding may be shared between the events. Beaked whales stranded in 
this event demonstrated brain and auditory system injuries, 
hemorrhages, and congestion in multiple organs, similar to the 
pathological findings of the Bahamas and Madeira stranding events. In 
addition, the necropsy results of Canary Islands stranding event lead 
to the hypothesis that the presence of disseminated and widespread gas 
bubbles and fat emboli were indicative of nitrogen bubble formation, 
similar to what might be expected in decompression sickness (Jepson et 
al., 2003; Fern[aacute]ndez et al., 2005; Fern[aacute]ndez et al., 
2012).
    Hanalei Bay (2004)--On July 3 and 4, 2004, approximately 150 to 200 
melon-headed whales occupied the shallow waters of the Hanalei Bay, 
Kaua'i, Hawaii for over 28 hrs. Attendees of a canoe blessing observed 
the animals entering the Bay in a single wave formation at 7 a.m. on 
July 3, 2004. The animals were observed moving back into the shore from 
the mouth of the Bay at 9 a.m. The usually pelagic animals milled in 
the shallow bay and were returned to deeper water with human assistance 
beginning at 9:30 a.m. on July 4, 2004, and were out of sight by 10:30 
a.m.
    Only one animal, a calf, was known to have died following this 
event. The animal was noted alive and alone in the Bay on the afternoon 
of July 4, 2004, and was found dead in the Bay the morning of July 5, 
2004. A full necropsy, magnetic resonance imaging, and computerized 
tomography examination were performed on the calf to determine the 
manner and cause of death. The combination of imaging, necropsy and 
histological analyses found no evidence of infectious, internal 
traumatic, congenital, or toxic factors. Cause of death could not be 
definitively determined, but it is likely that maternal separation, 
poor nutritional condition, and dehydration contributed to the final 
demise of the animal. Although it is not known when the calf was 
separated from its mother, the animals' movement into the Bay and 
subsequent milling and re-grouping may have contributed to the 
separation or lack of nursing, especially if the maternal bond was weak 
or this was an inexperienced mother with her first calf.
    Environmental factors, abiotic and biotic, were analyzed for any 
anomalous occurrences that would have contributed to the animals 
entering and remaining in Hanalei Bay. The Bay's bathymetry is similar 
to many other sites within the Hawaiian Island chain and dissimilar to 
sites that have been associated with mass strandings in other parts of 
the U.S. The weather conditions appeared to be normal for that time of 
year with no fronts or other significant features noted. There was no 
evidence of unusual distribution, occurrence of predator or prey 
species, or unusual harmful algal blooms, although Mobley et al., 2007 
suggested that the full moon cycle that occurred at that time may have 
influenced a run of squid into the Bay. Weather patterns and bathymetry 
that have been associated with mass strandings elsewhere were not found 
to occur in this instance.
    The Hanalei event was spatially and temporally correlated with 
RIMPAC. Official sonar training and tracking exercises in the Pacific 
Missile Range Facility (PMRF) warning area did not commence until 
approximately 8 a.m. on July 3 and were thus ruled out as a possible 
trigger for the initial movement into the Bay. However, six naval 
surface vessels transiting to the operational area on July 2 
intermittently transmitted active sonar (for approximately 9 hours 
total between the hours of 1:15 p.m. and 12:30 a.m.) as they approached 
from the south. The potential for these transmissions to have triggered 
the whales' movement into Hanalei Bay was investigated. Analyses with 
the information available indicated that animals to the south and east 
of Kaua'i could have detected active sonar transmissions on July 2, and 
reached Hanalei Bay on or before 7 a.m. on July 3. However, data 
limitations regarding the position of the whales prior to their arrival 
in the Bay, the magnitude of sonar exposure, behavioral responses of 
melon-headed whales to acoustic stimuli, and other possible relevant 
factors preclude a conclusive finding regarding the role of sonar in 
triggering this event. Propagation modeling suggests that transmissions 
from sonar use during the July 3 exercise in the PMRF warning area may 
have been detectable at the mouth of the Bay. If the animals responded 
negatively to these signals, it may have contributed to their continued 
presence in the Bay. The U.S. Navy ceased all active sonar 
transmissions during exercises in this range on the afternoon of July 
3. Subsequent to the cessation of sonar use, the animals were herded 
out of the Bay.
    While causation of this stranding event may never be unequivocally 
determined, NMFS consider the active sonar transmissions of July 2-3, 
2004, a plausible, if not likely, contributing factor in what may have 
been a confluence of events. This conclusion is based on the following: 
(1) The evidently anomalous nature of the stranding; (2) its close 
spatiotemporal correlation with wide-scale, sustained use of sonar 
systems previously associated with stranding of deep-diving marine 
mammals; (3) the directed movement of two groups of transmitting 
vessels toward the southeast and southwest coast of Kauai; (4) the 
results of acoustic propagation modeling and an analysis of possible 
animal transit times to the Bay; and (5) the absence of any other 
compelling causative

[[Page 46130]]

explanation. The initiation and persistence of this event may have 
resulted from an interaction of biological and physical factors. The 
biological factors may have included the presence of an apparently 
uncommon, deep-diving cetacean species (and possibly an offshore, non-
resident group), social interactions among the animals before or after 
they entered the Bay, and/or unknown predator or prey conditions. The 
physical factors may have included the presence of nearby deep water, 
multiple vessels transiting in a directed manner while transmitting 
active sonar over a sustained period, the presence of surface sound 
ducting conditions, and/or intermittent and random human interactions 
while the animals were in the Bay.
    A separate event involving melon-headed whales and rough-toothed 
dolphins took place over the same period of time in the Northern 
Mariana Islands (Jefferson et al., 2006), which is several thousand 
miles from Hawaii. Some 500 to 700 melon-headed whales came into 
Sasanhaya Bay on July 4, 2004, near the island of Rota and then left of 
their own accord after 5.5 hours; no known active sonar transmissions 
occurred in the vicinity of that event. The Rota incident led to 
scientific debate regarding what, if any, relationship the event had to 
the simultaneous events in Hawaii and whether they might be related by 
some common factor (e.g., there was a full moon on July 2, 2004, as 
well as during other melon-headed whale strandings and nearshore 
aggregations (Brownell et al., 2009; Lignon et al., 2007; Mobley et 
al., 2007). Brownell et al. (2009) compared the two incidents, along 
with one other stranding incident at Nuka Hiva in French Polynesia and 
normal resting behaviors observed at Palmyra Island, in regard to 
physical features in the areas, melon-headed whale behavior, and lunar 
cycles. Brownell et al., (2009) concluded that the rapid entry of the 
whales into Hanalei Bay, their movement into very shallow water far 
from the 100-m contour, their milling behavior (typical pre-stranding 
behavior), and their reluctance to leave the bay constituted an unusual 
event that was not similar to the events that occurred at Rota (but was 
similar to the events at Palmyra), which appear to be similar to 
observations of melon-headed whales resting normally at Palmyra Island. 
Additionally, there was no correlation between lunar cycle and the 
types of behaviors observed in the Brownell et al. (2009) examples. 
Since that time there have been two ``out of habitat'' or ``near mass 
strandings'' of melon-headed whales in the Philippines (Aragones et 
al., 2010). Pictures of one of these events depict grouping behavior 
like that displayed at Hanalei Bay in July 2004. No naval sonar 
activity was noted it the area, although it was suspected by the 
authors, based on personal communication with a government fisheries 
representative, that dynamite blasting in the area may have occurred 
within the days prior to one of the events (Aragones et al., 2010). 
Although melon-headed whales entering embayments may be infrequent and 
rare, there is precedent for this type of occurrence on other occasions 
in the absence of naval activity.
    Spain (2006)--The Spanish Cetacean Society reported an atypical 
mass stranding of four beaked whales that occurred January 26, 2006, on 
the southeast coast of Spain, near Mojacar (Gulf of Vera) in the 
Western Mediterranean Sea. According to the report, two of the whales 
were discovered the evening of January 26 and were found to be still 
alive (these later died). Two other whales were discovered during the 
day on January 27, but had already died. The first three animals were 
located near the town of Mojacar and the fourth animal was found dead, 
a few kilometers north of the first three animals. From January 25-26, 
2006, Standing NATO Response Force Maritime Group Two (five of seven 
ships including one U.S. ship under NATO Operational Control) had 
conducted active sonar training against a Spanish submarine within 50 
nm (93 km) of the stranding site.
    Veterinary pathologists necropsied the two male and two female 
Cuvier's beaked whales. According to the pathologists, the most likely 
primary cause of this type of beaked whale mass stranding event was 
anthropogenic acoustic activities, most probably anti-submarine MFAS 
used during the military naval exercises. However, no positive acoustic 
link was established as a direct cause of the stranding. Even though no 
causal link can be made between the stranding event and naval 
exercises, certain conditions may have existed in the exercise area 
that, in their aggregate, may have contributed to the marine mammal 
strandings (Freitas, 2004): Exercises were conducted in areas of at 
least 547 fathoms (1,000 m) depth near a shoreline where there is a 
rapid change in bathymetry on the order of 547 to 3,281 fathoms (1,000 
to 6,000 m) occurring across a relatively short horizontal distance 
(Freitas, 2004); multiple ships (in this instance, five) were operating 
MFAS in the same area over extended periods of time (in this case, 20 
hours) in close proximity; and exercises took place in an area 
surrounded by landmasses, or in an embayment. Exercises involving 
multiple ships employing MFAS near land may have produced sound 
directed towards a channel or embayment that may have cut off the lines 
of egress for the affected marine mammals (Freitas, 2004).

Association Between Mass Stranding Events and Exposure to MFAS

    Several authors have noted similarities between some of these 
stranding incidents: They occurred in islands or archipelagoes with 
deep water nearby, several appeared to have been associated with 
acoustic waveguides like surface ducting, and the sound fields created 
by ships transmitting MFAS (Cox et al., 2006, D'Spain et al., 2006). 
Although Cuvier's beaked whales have been the most common species 
involved in these stranding events (81 percent of the total number of 
stranded animals), other beaked whales (including Mesoplodon europeaus, 
M. densirostris, and Hyperoodon ampullatus) comprise 14 percent of the 
total. Other species (Stenella coeruleoalba, Kogia breviceps and 
Balaenoptera acutorostrata) have stranded, but in much lower numbers 
and less consistently than beaked whales.
    Based on the evidence available, however, NMFS cannot determine 
whether (a) Cuvier's beaked whale is more prone to injury from high-
intensity sound than other species; (b) their behavioral responses to 
sound makes them more likely to strand; or (c) they are more likely to 
be exposed to MFAS than other cetaceans (for reasons that remain 
unknown). Because the association between active sonar exposures and 
marine mammals mass stranding events is not consistent--some marine 
mammals strand without being exposed to sonar and some sonar 
transmissions are not associated with marine mammal stranding events 
despite their co-occurrence--other risk factors or a grouping of risk 
factors probably contribute to these stranding events.

Behaviorally Mediated Responses to MFAS That May Lead to Stranding

    Although the confluence of Navy MFAS with the other contributory 
factors noted in the report was identified as the cause of the 2000 
Bahamas stranding event, the specific mechanisms that led to that 
stranding (or the others) are not understood, and there is uncertainty 
regarding the ordering of effects that led to the stranding. It is 
unclear whether beaked

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whales were directly injured by sound (e.g., acoustically mediated 
bubble growth, as addressed above) prior to stranding or whether a 
behavioral response to sound occurred that ultimately caused the beaked 
whales to be injured and strand.
    Although causal relationships between beaked whale stranding events 
and active sonar remain unknown, several authors have hypothesized that 
stranding events involving these species in the Bahamas and Canary 
Islands may have been triggered when the whales changed their dive 
behavior in a startled response to exposure to active sonar or to 
further avoid exposure (Cox et al., 2006, Rommel et al., 2006). These 
authors proposed three mechanisms by which the behavioral responses of 
beaked whales upon being exposed to active sonar might result in a 
stranding event. These include the following: Gas bubble formation 
caused by excessively fast surfacing; remaining at the surface too long 
when tissues are supersaturated with nitrogen; or diving prematurely 
when extended time at the surface is necessary to eliminate excess 
nitrogen. More specifically, beaked whales that occur in deep waters 
that are in close proximity to shallow waters (for example, the 
``canyon areas'' that are cited in the Bahamas stranding event; see 
D'Spain and D'Amico, 2006), may respond to active sonar by swimming 
into shallow waters to avoid further exposures and strand if they were 
not able to swim back to deeper waters. Second, beaked whales exposed 
to active sonar might alter their dive behavior. Changes in their dive 
behavior might cause them to remain at the surface or at depth for 
extended periods of time which could lead to hypoxia directly by 
increasing their oxygen demands or indirectly by increasing their 
energy expenditures (to remain at depth) and increase their oxygen 
demands as a result. If beaked whales are at depth when they detect a 
ping from an active sonar transmission and change their dive profile, 
this could lead to the formation of significant gas bubbles, which 
could damage multiple organs or interfere with normal physiological 
function (Cox et al., 2006; Rommel et al., 2006; Zimmer and Tyack, 
2007). Baird et al. (2005) found that slow ascent rates from deep dives 
and long periods of time spent within 50 m of the surface were typical 
for both Cuvier's and Blainville's beaked whales, the two species 
involved in mass strandings related to naval sonar. These two 
behavioral mechanisms may be necessary to purge excessive dissolved 
nitrogen concentrated in their tissues during their frequent long dives 
(Baird et al., 2005). Baird et al. (2005) further suggests that 
abnormally rapid ascents or premature dives in response to high-
intensity sonar could indirectly result in physical harm to the beaked 
whales, through the mechanisms described above (gas bubble formation or 
non-elimination of excess nitrogen).
    Because many species of marine mammals make repetitive and 
prolonged dives to great depths, it has long been assumed that marine 
mammals have evolved physiological mechanisms to protect against the 
effects of rapid and repeated decompressions. Although several 
investigators have identified physiological adaptations that may 
protect marine mammals against nitrogen gas supersaturation (alveolar 
collapse and elective circulation; Kooyman et al., 1972; Ridgway and 
Howard, 1979), Ridgway and Howard (1979) reported that bottlenose 
dolphins that were trained to dive repeatedly had muscle tissues that 
were substantially supersaturated with nitrogen gas. Houser et al. 
(2001) used these data to model the accumulation of nitrogen gas within 
the muscle tissue of other marine mammal species and concluded that 
cetaceans that dive deep and have slow ascent or descent speeds would 
have tissues that are more supersaturated with nitrogen gas than other 
marine mammals. Based on these data, Cox et al. (2006) hypothesized 
that a critical dive sequence might make beaked whales more prone to 
stranding in response to acoustic exposures. The sequence began with 
(1) very deep (to depths as deep as 2 kilometers) and long (as long as 
90 minutes) foraging dives; (2) relatively slow, controlled ascents; 
and (3) a series of ``bounce'' dives between 100 and 400 m in depth 
(also see Zimmer and Tyack, 2007). They concluded that acoustic 
exposures that disrupted any part of this dive sequence (for example, 
causing beaked whales to spend more time at surface without the bounce 
dives that are necessary to recover from the deep dive) could produce 
excessive levels of nitrogen supersaturation in their tissues, leading 
to gas bubble and emboli formation that produces pathologies similar to 
decompression sickness.
    Zimmer and Tyack (2007) modeled nitrogen tension and bubble growth 
in several tissue compartments for several hypothetical dive profiles 
and concluded that repetitive shallow dives (defined as a dive where 
depth does not exceed the depth of alveolar collapse, approximately 72 
m for Ziphius), perhaps as a consequence of an extended avoidance 
reaction to sonar sound, could pose a risk for decompression sickness 
and that this risk should increase with the duration of the response. 
Their models also suggested that unrealistically rapid ascent rates of 
ascent from normal dive behaviors are unlikely to result in 
supersaturation to the extent that bubble formation would be expected. 
Tyack et al. (2006) suggested that emboli observed in animals exposed 
to mid-frequency range sonar (Jepson et al., 2003; Fernandez et al., 
2005; Fern[aacute]ndez et al., 2012) could stem from a behavioral 
response that involves repeated dives shallower than the depth of lung 
collapse. Given that nitrogen gas accumulation is a passive process 
(i.e. nitrogen is metabolically inert), a bottlenose dolphin was 
trained to repetitively dive a profile predicted to elevate nitrogen 
saturation to the point that nitrogen bubble formation was predicted to 
occur. However, inspection of the vascular system of the dolphin via 
ultrasound did not demonstrate the formation of asymptomatic nitrogen 
gas bubbles (Houser et al., 2007). Baird et al. (2008), in a beaked 
whale tagging study off Hawaii, showed that deep dives are equally 
common during day or night, but ``bounce dives'' are typically a 
daytime behavior, possibly associated with visual predator avoidance. 
This may indicate that ``bounce dives'' are associated with something 
other than behavioral regulation of dissolved nitrogen levels, which 
would be necessary day and night.
    If marine mammals respond to a Navy vessel that is transmitting 
active sonar in the same way that they might respond to a predator, 
their probability of flight responses should increase when they 
perceive that Navy vessels are approaching them directly, because a 
direct approach may convey detection and intent to capture (Burger and 
Gochfeld, 1981, 1990; Cooper, 1997, 1998). The probability of flight 
responses should also increase as received levels of active sonar 
increase (and the ship is, therefore, closer) and as ship speeds 
increase (that is, as approach speeds increase). For example, the 
probability of flight responses in Dall's sheep (Ovis dalli dalli) 
(Frid 2001a, b), ringed seals (Phoca hispida) (Born et al., 1999), 
Pacific brant (Branta bernic nigricans) and Canada geese (B. 
Canadensis) increased as a helicopter or fixed-wing aircraft approached 
groups of these animals more directly (Ward et al., 1999). Bald eagles 
(Haliaeetus leucocephalus) perched on trees alongside a river were also 
more likely to flee from a paddle raft when their perches were closer 
to the river or were

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closer to the ground (Steidl and Anthony, 1996).
    Despite the many theories involving bubble formation (both as a 
direct cause of injury (see Acoustically Mediated Bubble Growth 
Section) and an indirect cause of stranding (See Behaviorally Mediated 
Bubble Growth Section)), Southall et al., (2007) summarizes that there 
is either scientific disagreement or a lack of information regarding 
each of the following important points: (1) Received acoustical 
exposure conditions for animals involved in stranding events; (2) 
pathological interpretation of observed lesions in stranded marine 
mammals; (3) acoustic exposure conditions required to induce such 
physical trauma directly; (4) whether noise exposure may cause 
behavioral reactions (such as atypical diving behavior) that 
secondarily cause bubble formation and tissue damage; and (5) the 
extent the post mortem artifacts introduced by decomposition before 
sampling, handling, freezing, or necropsy procedures affect 
interpretation of observed lesions.

Impulsive Sources

    Underwater explosive detonations send a shock wave and sound energy 
through the water and can release gaseous by-products, create an 
oscillating bubble, or cause a plume of water to shoot up from the 
water surface. The shock wave and accompanying noise are of most 
concern to marine animals. Depending on the intensity of the shock wave 
and size, location, and depth of the animal, an animal can be injured, 
killed, suffer non-lethal physical effects, experience hearing related 
effects with or without behavioral responses, or exhibit temporary 
behavioral responses or tolerance from hearing the blast sound. 
Generally, exposures to higher levels of impulse and pressure levels 
would result in greater impacts to an individual animal.
    Injuries resulting from a shock wave take place at boundaries 
between tissues of different densities. Different velocities are 
imparted to tissues of different densities, and this can lead to their 
physical disruption. Blast effects are greatest at the gas-liquid 
interface (Landsberg, 2000). Gas-containing organs, particularly the 
lungs and gastrointestinal tract, are especially susceptible (Goertner, 
1982; Hill, 1978; Yelverton et al., 1973). In addition, gas-containing 
organs including the nasal sacs, larynx, pharynx, trachea, and lungs 
may be damaged by compression/expansion caused by the oscillations of 
the blast gas bubble (Reidenberg and Laitman, 2003). Intestinal walls 
can bruise or rupture, with subsequent hemorrhage and escape of gut 
contents into the body cavity. Less severe gastrointestinal tract 
injuries include contusions, petechiae (small red or purple spots 
caused by bleeding in the skin), and slight hemorrhaging (Yelverton et 
al., 1973).
    Because the ears are the most sensitive to pressure, they are the 
organs most susceptible to injury (Ketten, 2000). Sound-related damage 
associated with sound energy from detonations can be theoretically 
distinct from injury from the shock wave, particularly farther from the 
explosion. If a noise is audible to an animal, it has the potential to 
damage the animal's hearing by causing decreased sensitivity (Ketten, 
1995). Sound-related trauma can be lethal or sublethal. Lethal impacts 
are those that result in immediate death or serious debilitation in or 
near an intense source and are not, technically, pure acoustic trauma 
(Ketten, 1995). Sublethal impacts include hearing loss, which is caused 
by exposures to perceptible sounds. Severe damage (from the shock wave) 
to the ears includes tympanic membrane rupture, fracture of the 
ossicles, damage to the cochlea, hemorrhage, and cerebrospinal fluid 
leakage into the middle ear. Moderate injury implies partial hearing 
loss due to tympanic membrane rupture and blood in the middle ear. 
Permanent hearing loss also can occur when the hair cells are damaged 
by one very loud event, as well as by prolonged exposure to a loud 
noise or chronic exposure to noise. The level of impact from blasts 
depends on both an animal's location and, at outer zones, on its 
sensitivity to the residual noise (Ketten, 1995).
    There have been fewer studies addressing the behavioral effects of 
explosives on marine mammals compared to MFAS/HFAS. However, though the 
nature of the sound waves emitted from an explosion are different (in 
shape and rise time) from MFAS/HFAS, NMFS still anticipates the same 
sorts of behavioral responses to result from repeated explosive 
detonations (a smaller range of likely less severe responses (i.e., not 
rising to the level of MMPA harassment) would be expected to occur as a 
result of exposure to a single explosive detonation that was not 
powerful enough or close enough to the animal to cause TTS or injury).
    Baleen whales have shown a variety of responses to impulse sound 
sources, including avoidance, reduced surface intervals, altered 
swimming behavior, and changes in vocalization rates (Richardson et 
al., 1995; Gordon et al., 2003; Southall, 2007). While most bowhead 
whales did not show active avoidance until within 8 km of seismic 
vessels (Richardson et al., 1995), some whales avoided vessels by more 
than 20 km at received levels as low as 120 dB re 1 [micro]Pa rms. 
Additionally, Malme et al. (1988) observed clear changes in diving and 
respiration patterns in bowheads at ranges up to 73 km from seismic 
vessels, with received levels as low as 125 dB re 1 [micro]Pa.
    Gray whales migrating along the U.S. west coast showed avoidance 
responses to seismic vessels by 10 percent of animals at 164 dB re 1 
[micro]Pa, and by 90 percent of animals at 190 dB re 1 [micro]Pa, with 
similar results for whales in the Bering Sea (Malme 1986, 1988). In 
contrast, noise from seismic surveys was not found to impact feeding 
behavior or exhalation rates while resting or diving in western gray 
whales off the coast of Russia (Yazvenko et al., 2007; Gailey et al., 
2007).
    Humpback whales showed avoidance behavior at ranges of 5-8 km from 
a seismic array during observational studies and controlled exposure 
experiments in western Australia (McCauley, 1998; Todd et al., 1996) 
found no clear short-term behavioral responses by foraging humpbacks to 
explosions associated with construction operations in Newfoundland, but 
did see a trend of increased rates of net entanglement and a shift to a 
higher incidence of net entanglement closer to the noise source.
    Seismic pulses at average received levels of 131 dB re 1 
micropascal squared second ([micro]Pa\2\-s) caused blue whales to 
increase call production (Di Iorio and Clark, 2010). In contrast, 
McDonald et al. (1995) tracked a blue whale with seafloor seismometers 
and reported that it stopped vocalizing and changed its travel 
direction at a range of 10 km from the seismic vessel (estimated 
received level 143 dB re 1 [micro]Pa peak-to-peak). These studies 
demonstrate that even low levels of noise received far from the noise 
source can induce behavioral responses.
    Madsen et al. (2006) and Miller et al. (2009) tagged and monitored 
eight sperm whales in the Gulf of Mexico exposed to seismic airgun 
surveys. Sound sources were from approximately 2 to 7 nm away from the 
whales and based on multipath propagation received levels were as high 
as 162 dB SPL re 1 [micro]Pa with energy content greatest between 0.3 
and 3.0 kHz (Madsen, 2006). The whales showed no horizontal avoidance, 
although the whale that was approached most closely had an extended 
resting period and did not resume foraging until the airguns had ceased 
firing (Miller et al., 2009). The remaining whales continued to

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execute foraging dives throughout exposure; however, swimming movements 
during foraging dives were 6 percent lower during exposure than control 
periods, suggesting subtle effects of noise on foraging behavior 
(Miller et al., 2009). Captive bottlenose dolphins sometimes vocalized 
after an exposure to impulse sound from a seismic watergun (Finneran et 
al., 2010a).
    A review of behavioral reactions by pinnipeds to impulse noise can 
be found in Richardson et al. (1995) and Southall et al. (2007). 
Blackwell et al. (2004) observed that ringed seals exhibited little or 
no reaction to pipe-driving noise with mean underwater levels of 157 dB 
re 1 [micro]Pa rms and in air levels of 112 dB re 20 [micro]Pa, 
suggesting that the seals had habituated to the noise. In contrast, 
captive California sea lions avoided sounds from an impulse source at 
levels of 165-170 dB re 1 [micro]Pa (Finneran et al., 2003b). 
Experimentally, G[ouml]tz and Janik (2011) tested underwater, startle 
responses to a startling sound (sound with a rapid rise time and a 93 
dB sensation level [the level above the animal's threshold at that 
frequency]) and a non-startling sound (sound with the same level, but 
with a slower rise time) in wild-captured gray seals. The animals 
exposed to the startling treatment avoided a known food source, whereas 
animals exposed to the non-startling treatment did not react or 
habituated during the exposure period. The results of this study 
highlight the importance of the characteristics of the acoustic signal 
in an animal's response of habituation.

Vessels

    Commercial and Navy ship strikes of cetaceans can cause major 
wounds, which may lead to the death of the animal. An animal at the 
surface could be struck directly by a vessel, a surfacing animal could 
hit the bottom of a vessel, or an animal just below the surface could 
be cut by a vessel's propeller. The severity of injuries typically 
depends on the size and speed of the vessel (Knowlton and Kraus, 2001; 
Laist et al., 2001; Vanderlaan and Taggart, 2007). The most vulnerable 
marine mammals are those that spend extended periods of time at the 
surface in order to restore oxygen levels within their tissues after 
deep dives (e.g., the sperm whale). In addition, some baleen whales, 
such as the North Atlantic right whale, seem generally unresponsive to 
vessel sound, making them more susceptible to vessel collisions 
(Nowacek et al., 2004). These species are primarily large, slow moving 
whales. Smaller marine mammals (e.g., bottlenose dolphin) move quickly 
through the water column and are often seen riding the bow wave of 
large ships. Marine mammal responses to vessels may include avoidance 
and changes in dive pattern (NRC, 2003).
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike results in death (Knowlton and Kraus, 2001; 
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart, 
2007). In assessing records in which vessel speed was known, Laist et 
al. (2001) found a direct relationship between the occurrence of a 
whale strike and the speed of the vessel involved in the collision. The 
authors concluded that most deaths occurred when a vessel was traveling 
in excess of 13 knots.
    Jensen and Silber (2003) detailed 292 records of known or probable 
ship strikes of all large whale species from 1975 to 2002. Of these, 
vessel speed at the time of collision was reported for 58 cases. Of 
these cases, 39 (or 67 percent) resulted in serious injury or death (19 
of those resulted in serious injury as determined by blood in the 
water, propeller gashes or severed tailstock, and fractured skull, jaw, 
vertebrae, hemorrhaging, massive bruising or other injuries noted 
during necropsy and 20 resulted in death). Operating speeds of vessels 
that struck various species of large whales ranged from 2 to 51 knots. 
The majority (79 percent) of these strikes occurred at speeds of 13 
knots or greater. The average speed that resulted in serious injury or 
death was 18.6 knots. Pace and Silber (2005) found that the probability 
of death or serious injury increased rapidly with increasing vessel 
speed. Specifically, the predicted probability of serious injury or 
death increased from 45 to 75 percent as vessel speed increased from 10 
to 14 knots, and exceeded 90 percent at 17 knots. Higher speeds during 
collisions result in greater force of impact and also appear to 
increase the chance of severe injuries or death. While modeling studies 
have suggested that hydrodynamic forces pulling whales toward the 
vessel hull increase with increasing speed (Clyne, 1999; Knowlton et 
al., 1995), this is inconsistent with Silber et al. (2010), which 
demonstrated that there is no such relationship (i.e., hydrodynamic 
forces are independent of speed).
    The Jensen and Silber (2003) report notes that the database 
represents a minimum number of collisions, because the vast majority 
probably goes undetected or unreported. In contrast, Navy vessels are 
likely to detect any strike that does occur, and they are required to 
report all ship strikes involving marine mammals. Overall, the 
percentages of Navy traffic relative to overall large shipping traffic 
are very small (on the order of 2 percent).
    There are no records of any Navy vessel strikes to marine mammals 
during training or testing activities in the MITT Study Area. There 
have been Navy strikes of large whales in areas outside the Study Area, 
such as Hawaii and Southern California. However, these areas differ 
significantly from the Study Area given that both Hawaii and Southern 
California have a much higher number of Navy vessel activities and much 
higher densities of large whales.
    Other efforts have been undertaken to investigate the impact from 
vessels (both whale-watching and general vessel traffic noise) and 
demonstrated impacts do occur (Bain, 2002; Erbe, 2002; Lusseau, 2009; 
Williams et al., 2006, 2009, 2011b, 2013, 2014a, 2014b; Noren et al., 
2009; Read et al., 2014; Rolland et al., 2012; Pirotta et al., 2015). 
This body of research for the most part has investigated impacts 
associated with the presence of chronic stressors, which differ 
significantly from generally intermittent Navy training and testing 
activities. For example, in an analysis of energy costs to killer 
whales, Williams et al. (2009) suggested that whale-watching in the 
Johnstone Strait resulted in lost feeding opportunities due to vessel 
disturbance, which could carry higher costs than other measures of 
behavioral change might suggest. Ayres et al. (2012) recently reported 
on research in the Salish Sea involving the measurement of southern 
resident killer whale fecal hormones to assess two potential threats to 
the species recovery: Lack of prey (salmon) and impacts to behavior 
from vessel traffic. Ayres et al. (2012) suggested that the lack of 
prey overshadowed any population-level physiological impacts on 
southern resident killer whales from vessel traffic.

Mitigation

    Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the 
``permissible methods of taking pursuant to such activity, and other 
means of effecting the least practicable adverse impact on such species 
or stock and its habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.'' NMFS' duty under 
this ``least practicable adverse 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

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impacts are minimized by reducing impacts on individual marine mammals, 
not all takes have a reasonable potential for translating to 
population-level impacts. NMFS' objective under the ``least practicable 
adverse impact'' standard is to design mitigation targeting those 
impacts on individual marine mammals that are reasonably likely to 
contribute to adverse population-level effects.
    The NDAA of 2004 amended the MMPA as it relates to military-
readiness activities and the ITA process such that ``least practicable 
adverse impact'' shall include consideration of personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
``military readiness activity.'' The training and testing activities 
described in the Navy's LOA application are considered military 
readiness activities.
    In Conservation Council for Hawaii v. National Marine Fisheries 
Service, No. 1:13-cv-00684 (D. Hawaii March 31, 2015), the court stated 
that NMFS ``appear[s] to think that [it] satisf[ies] the statutory 
`least practicable adverse impact' requirement with a `negligible 
impact' finding.'' In light of the court's decision, we take this 
opportunity to make clear our position that the ``negligible impact'' 
and ``least practicable adverse impact'' requirements are distinct, 
even though the focus of both is on population-level impacts.
    A population-level impact is an impact on the population numbers 
(survival) or growth and reproductive rates (recruitment) of a 
particular marine mammal species or stock. As we noted in the preamble 
to our general MMPA implementing regulations, not every population-
level impact violates the negligible impact requirement. As we 
explained, the negligible impact standard does not require a finding 
that the anticipated take will have ``no effect'' on population numbers 
or growth rates: ``The statutory standard does not require that the 
same recovery rate be maintained, rather that no significant effect on 
annual rates of recruitment or survival occurs . . . [T]he key factor 
is the significance of the level of impact on rates of recruitment or 
survival. Only insignificant impacts on long-term population levels and 
trends can be treated as negligible.'' See 54 FR 40338, 40341-42 (Sept 
29, 1989). Nevertheless, while insignificant impacts on population 
numbers or growth rates may satisfy the negligible impact requirement, 
such impacts still must be mitigated, to the extent practicable, under 
the ``least practicable adverse impact'' requirement. Thus, the 
negligible impact and least practicable adverse impact requirements are 
clearly distinct, even though both focus on population-level effects.
    As explained in the proposed rule, 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 accomplishing one or more of the general goals listed below:
    a. Avoid or minimize injury or death of marine mammals wherever 
possible (goals b, c, and d may contribute to this goal).
    b. Reduce the numbers of marine mammals (total number or number at 
biologically important time or location) exposed to received levels of 
MFAS/HFAS, underwater detonations, or other activities expected to 
result in the take of marine mammals (this goal may contribute to a, 
above, or to reducing harassment takes only).
    c. Reduce the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of MFAS/HFAS, underwater detonations, or other 
activities expected to result in the take of marine mammals (this goal 
may contribute to a, above, or to reducing harassment takes only).
    d. Reduce the intensity of exposures (either total number or number 
at biologically important time or location) to received levels of MFAS/
HFAS, underwater detonations, 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).
    e. Avoid or minimize 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.
    f. For monitoring directly related to mitigation--increase the 
probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation (shut-down zone, etc.).
    Our final evaluation of measures that meet one or more of the above 
goals includes consideration of the following factors in relation to 
one another: The manner in which, and the degree to which, the 
successful implementation of the mitigation measures is expected to 
reduce population-level impacts to marine mammal species and stocks and 
impacts to their habitat; the proven or likely efficacy of the 
measures; and the practicability of the suite of measures for applicant 
implementation, including consideration of personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
military readiness activity.
    NMFS reviewed the proposed activities and the suite of proposed 
mitigation measures as described in the Navy's LOA application to 
determine if they would result in the least practicable adverse effect 
on marine mammals. NMFS described the Navy's proposed mitigation 
measures in detail in the proposed rule (79 FR 15388, March 19, 2014; 
pages 15414-15422), and they have not changed. NMFS worked with the 
Navy in the development of the Navy's initially proposed measures, and 
they are informed by years of experience and monitoring. As described 
in the Mitigation Conclusions below and in responses to comments, and 
in the MITT FEIS/OEIS, additional measures were considered and 
analyzed, but ultimately not chosen for implementation. Below are the 
mitigation measures as agreed upon by the Navy and NMFS. For additional 
details regarding the Navy's mitigation measures, see Chapter 5 in the 
MITT FEIS/OEIS.
     At least one Lookout during applicable training and 
testing activities;
     Mitigation zones ranging from 70 yards (yd) (64 m) to 2.5 
nautical miles (nm) during applicable activities that involve the use 
of impulse and non-impulse sources to avoid or reduce the potential for 
onset of the lowest level of injury, PTS, out to the predicted maximum 
range (Tables 6 and 7);
     Mitigation zones of 500 yd (457 m) for whales and 200 yd 
(183 m) for all other marine mammals (except bow riding dolphins) 
during vessel movement, and a mitigation zone of 250 yd (229 m) for 
marine mammals during use of towed in-water devices being towed from 
manned platforms; and
     Mitigation zones ranging from 200 yd (183 m) to 1,000 yd 
(914 m) during activities that involve the use of non-explosive 
practice munitions.

[[Page 46135]]



                                         Table 6--Predicted Ranges to TTS, PTS, and Recommended Mitigation Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Predicted average
         Activity category             Bin (representative      Predicted average      (longest) range to     Predicted maximum         Recommended
                                            source)*         (longest) range to TTS           PTS                range to PTS         mitigation  zone
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Non-Impulse Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-Frequency and Hull-Mounted Mid-  MF1 (SQS-53 ASW hull-   Page 83...............  Page 83..............  Not Applicable.......  6 dB power down at
 Frequency Active Sonar.              mounted sonar).        3,281 yd (3.5 km) for   100 yd (91 m) for one                          1,000 yd. (914 m);
                                                              one ping.               ping.                                        4 dB power down at
                                                                                                                                    500 yd. (457 m); and
                                                                                                                                   shutdown at 200 yd.
                                                                                                                                    (183 m).
                                     LF4 (low-frequency      3,821 yd. (3.5 km) for  100 yd. (91 m) for     Not Applicable.......  200 yd. (183 m).**
                                      sonar) **.              one ping.               one ping.
--------------------------------------------------------------------------------------------------------------------------------------------------------
High-Frequency and Non-Hull Mounted  MF4 (AQS-22 ASW         230 yd. (210 m) for     20 yd. (18 m) for one  Not Applicable.......  200 yd. (183 m).
 Mid-Frequency Active Sonar.          dipping sonar).         one ping.               ping.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Explosive and Impulse Sound
--------------------------------------------------------------------------------------------------------------------------------------------------------
Improved Extended Echo Ranging       E4 (Explosive           434 yd. (397 m).......  156 yd. (143 m)......  563 yd. (515 m)......  600 yd. (549 m).
 Sonobuoys.                           sonobuoy).
Explosive Sonobuoys using 0.6-2.5    E3 (Explosive           290 yd. (265 m).......  113 yd. (103 m)......  309 yd. (283 m)......  350 yd. (320 m).
 lb. NEW.                             sonobuoy).
Anti-Swimmer Grenades..............  E2 (Up to 0.5 lb. NEW)  190 yd. (174 m).......  83 yd. (76 m)........  182 yd. (167 m)......  200 yd. (183 m).
                                    --------------------------------------------------------------------------------------------------------------------
Mine Countermeasure and                                                          NEW dependent (see Table 7).
 Neutralization Activities Using
 Positive Control Firing Devices.
                                    --------------------------------------------------------------------------------------------------------------------
Mine Neutralization Diver-Placed     E6 (Up to 20 lb. NEW).  407 yd. (372 m).......  98 yd. (90 m)........  102 yd. (93 m).......  1,000 yd. (914 m).
 Mines Using Time-Delay Firing
 Devices.
Gunnery Exercises--Small- and        E2 (40 mm projectile).  190 yd. (174 m).......  83 yd. (76 m)........  182 yd. (167 m)......  200 yd. (183 m).
 Medium-Caliber (Surface Target).
Gunnery Exercises--Large-Caliber     E5 (5 in. projectiles   453 yd. (414 m).......  186 yd. (170 m)......  526 yd. (481 m)......  600 yd. (549 m).
 (Surface Target).                    at the surface ***).
Missile Exercises up to 250 lb. NEW  E9 (Maverick missile).  949 yd. (868 m).......  398 yd. (364 m)......  699 yd. (639 m)......  900 yd. (823 m).
 (Surface Target).
Missile Exercises > 250 to 500 lb.   E10 (Harpoon missile).  1,832 yd. (1,675 m)...  731 yd. (668 m)......  1,883 yd. (1,721 m)..  2,000 yd. (1.8 km).
 NEW (Surface Target).
Bombing Exercises..................  E12 (MK-84 2,000 lb.    2,513 yd. (2.3 km)....  991 yd. (906 m)......  2,474 yd. (2.3 km)...  2,500 yd. (2.3
                                      bomb).                                                                                        km).****
Torpedo (Explosive) Testing........  E11 (MK-48 torpedo)...  1,632 yd. (1.5 km)....  697 yd. (637 m)......  2,021 yd. (1.8 km)...  2,100 yd. (1.9 km).\
Sinking Exercises..................  E12 (Various sources    2,513 yd. (2.3 km)....  991 yd. (906 m)......  2,474 yd. (2.3 km)...  2.5 nm.****
                                      up to the MK-84 2,000
                                      lb. bomb).
--------------------------------------------------------------------------------------------------------------------------------------------------------
ASW = anti-submarine warfare, km = kilometers, lb.= pound(s), m = meters, mm = millimeters, NEW = net explosive weight, nm = nautical miles, PTS =
  Permanent Threshold Shift, TTS = Temporary Threshold Shift, yd. = yards
* This table does not provide an inclusive list of source bins; bins presented here represent the source bin with the largest range to effects within
  the given activity category.
** The representative source bin and mitigation zone applies to sources that cannot be powered down (e.g., bins LF4 and LF5).
*** The representative source bin E5 has different range to effects depending on the depth of activity occurrence (at the surface or at various depths).
**** Recommended mitigation zones are larger than the modeled injury zones to account for multiple types of sources or charges being used.


[[Page 46136]]


                   Table 7--Predicted Ranges to Effects and Mitigation Zone Radius for Mine Countermeasure and Neutralization Activities Using Positive Control Firing Devices
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               General mine countermeasure and neutralization activities using    Mine countermeasure and neutralization activities using diver
                                                                              positive control firing devices *                             placed charges under positive control **
                                                             -----------------------------------------------------------------------------------------------------------------------------------
          Charge size net  explosive weight  (bins)              Predicted       Predicted       Predicted                         Predicted       Predicted       Predicted
                                                               average range   average range   maximum range     Recommended     average range   average range   maximum range     Recommended
                                                                  to TTS          to PTS          to PTS       mitigation zone      to TTS          to PTS          to PTS       mitigation zone
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2.5-5 lb. (1.2-2.3 kg) (E4).................................          434 yd          197 yd          563 yd           600 yd.          545 yd          169 yd          301 yd            350 yd
                                                                     (474 m)         (180 m)         (515 m)           (549 m)         (498 m)         (155 m)         (275 m)          (320 m).
5-10 lb. (2.7-4.5 kg) (E5)..................................          525 yd          204 yd          649 yd            800 yd          587 yd          203 yd          464 yd            500 yd
                                                                     (480 m)         (187 m)         (593 m)           (732 m)         (537 m)         (185 m)         (424 m)          (457 m).
>10-20 lb. (5-9.1 kg) (E6)..................................          766 yd          288 yd          648 yd            800 yd          647 yd          232 yd          469 yd            500 yd
                                                                     (700 m)         (263 m)         (593 m)           (732 m)         (592 m)         (212 m)         (429 m)           (457 m)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PTS: permanent threshold shift; TTS: temporary threshold shift.
* These mitigation zones are applicable to all mine countermeasure and neutralization activities conducted in all locations specified in Chapter 2 of the Navy's LOA application.
** These mitigation zones are only applicable to mine countermeasure and neutralization activities involving the use of diver placed charges. These activities are conducted in shallow-water
  and the mitigation zones are based only on the functional hearing groups with species that occur in these areas (mid-frequency cetaceans and sea turtles).

Stranding Response Plan

    NMFS and the Navy developed a Stranding Response Plan for MIRC in 
2010 as part of the incidental take authorization process. In addition, 
Regional Stranding Implementation Assistance Plans for MIRC were 
established in 2011 per a Navy-NMFS MOU. The Stranding Response Plan is 
specifically intended to outline the applicable requirements in the 
event that a marine mammal stranding is reported in the MIRC during a 
major training exercise. NMFS considers all plausible causes within the 
course of a stranding investigation and these plans in no way presume 
that any strandings in a Navy range complex are related to, or caused 
by, Navy training and testing activities, absent a determination made 
during investigation. The plans are designed to address mitigation, 
monitoring, and compliance. The Navy worked with NMFS to refine these 
plans for the new MITT Study Area (to include regionally specific plans 
that include more logistical detail) and these revised plans are 
available here: http://www.nmfs.noaa.gov/pr/permits/incidental/. 
Modifications to the Stranding Response Plan may also be made through 
the adaptive management process.

Mitigation Conclusions

    NMFS has carefully evaluated the Navy's proposed mitigation 
measures--many of which were developed with NMFS' input during the 
first phase of authorizations--and considered a range of other measures 
in the context of ensuring that NMFS prescribes the means of effecting 
the least practicable adverse impact on the affected marine mammal 
species and stocks and their habitat. Based on our evaluation of the 
Navy's proposed measures, as well as other measures considered by NMFS, 
NMFS has determined that the Navy's proposed mitigation measures 
(especially when the adaptive management component is taken into 
consideration (see Adaptive Management, below)) are adequate means of 
effecting the least practicable adverse impacts on marine mammals 
species or stocks and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, while 
also considering personnel safety, practicality of implementation, and 
impact on the effectiveness of the military readiness activity.

Monitoring

    Section 101(a)(5)(A) of the MMPA states that in order to issue an 
ITA for an activity, 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 LOAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present.
    NMFS provided an overview of Navy monitoring and research, 
highlighted recent findings, and explained the Navy's new approach to 
monitoring in the proposed rule (79 FR 15388; pages 15422-15426). Below 
is a summary of the Navy's Integrated Comprehensive Monitoring Program 
(ICMP) and the Navy's Strategic Planning Process for Marine Species 
Monitoring.

Integrated Comprehensive Monitoring Program

    The Navy's ICMP is intended to coordinate monitoring efforts across 
all regions and to allocate the most appropriate level and type of 
effort for each range complex based on a set of standardized 
objectives, and in acknowledgement of regional expertise and resource 
availability. The ICMP is designed to be flexible, scalable, and 
adaptable through the adaptive management and strategic planning 
processes to periodically assess progress and reevaluate objectives. 
Although the ICMP does not specify actual monitoring field work or 
projects, it does establish top-level goals that have been developed in 
coordination with NMFS. As the ICMP is implemented, detailed and 
specific studies will be developed which support the Navy's top-level 
monitoring goals. In essence, the ICMP directs that monitoring 
activities relating to the effects of Navy training and testing 
activities on marine species should be designed to contribute towards 
one or more of the following top-level goals:
     An increase in our understanding of the likely occurrence 
of marine mammals and/or ESA-listed marine species in the vicinity of 
the action (i.e., presence, abundance, distribution, and/or density of 
species);
     An increase in our understanding of the nature, scope, or 
context of the likely exposure of marine mammals and/or ESA-listed 
species to any of the potential stressor(s) associated with the action 
(e.g., tonal and impulsive sound), through better understanding of one 
or more of the following: (1) the action and the environment in which 
it occurs (e.g., sound source characterization, propagation, and 
ambient noise levels);

[[Page 46137]]

(2) the affected species (e.g., life history or dive patterns); (3) the 
likely co-occurrence of marine mammals and/or ESA-listed marine species 
with the action (in whole or part) associated with specific adverse 
effects, and/or; (4) the likely biological or behavioral context of 
exposure to the stressor for the marine mammal and/or ESA-listed marine 
species (e.g., age class of exposed animals or known pupping, calving 
or feeding areas);
     An increase in our understanding of how individual marine 
mammals or ESA-listed marine species respond (behaviorally or 
physiologically) to the specific stressors associated with the action 
(in specific contexts, where possible, e.g., at what distance or 
received level);
     An increase in our understanding of how anticipated 
individual responses, to individual stressors or anticipated 
combinations of stressors, may impact either: (1) the long-term fitness 
and survival of an individual; or (2) the population, species, or stock 
(e.g., through effects on annual rates of recruitment or survival);
     An increase in our understanding of the effectiveness of 
mitigation and monitoring measures;
     A better understanding and record of the manner in which 
the authorized entity complies with the ITA and Incidental Take 
Statement;
     An increase in the probability of detecting marine mammals 
(through improved technology or methods), both specifically within the 
safety zone (thus allowing for more effective implementation of the 
mitigation) and in general, to better achieve the above goals; and
     A reduction in the adverse impact of activities to the 
least practicable level, as defined in the MMPA.
    Monitoring addresses the ICMP top-level goals through a collection 
of specific regional and ocean basin studies based on scientific 
objectives. Quantitative metrics of monitoring effort (e.g., 20 days of 
aerial surveys) are not a specific requirement. The adaptive management 
process and reporting requirements serve as the basis for evaluating 
performance and compliance, primarily considering the quality of the 
work and results produced, as well as peer review and publications, and 
public dissemination of information, reports, and data. Details of the 
ICMP and all MIRC monitoring reports are available online (http://www.navymarinespeciesmonitoring.us/).

Strategic Planning Process for Marine Species Monitoring

    The Navy also developed the Strategic Planning Process for Marine 
Species Monitoring, which establishes the guidelines and processes 
necessary to develop, evaluate, and fund individual projects based on 
objective scientific study questions. The process uses an underlying 
framework designed around top-level goals, a conceptual framework 
incorporating a progression of knowledge, and consultation with a 
Scientific Advisory Group and other regional experts. The Strategic 
Planning Process for Marine Species Monitoring has been used to set 
intermediate scientific objectives, identify potential species of 
interest at a regional scale, and evaluate and select specific 
monitoring projects to fund or continue supporting for a given fiscal 
year. This process would also address relative investments to different 
range complexes based on goals across all range complexes, and 
monitoring would leverage multiple techniques for data acquisition and 
analysis whenever possible. The Strategic Planning Process for Marine 
Species Monitoring is also available online (http://www.navymarinespeciesmonitoring.us/).

Past Monitoring in the MITT Study Area

    NMFS has received multiple years' worth of annual exercise and 
monitoring reports addressing active sonar use and explosive 
detonations within the MIRC and other Navy range complexes. The data 
and information contained in these reports have been considered in 
developing mitigation and monitoring measures for the proposed training 
and testing activities within the Study Area. The Navy's annual 
exercise and monitoring reports may be viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental/ and http://www.navymarinespeciesmonitoring.us. NMFS' summary of the Navy's annual 
monitoring reports was included in the proposed rule (79 FR 15388, 
March 19, 2014; pages 15423-15424). The Navy has since submitted to 
NMFS the 5-year Comprehensive Monitoring Report for MIRC, which is 
available at: http://www.nmfs.noaa.gov/pr/permits/incidental/.

Proposed Monitoring for the MITT Study Area

    Based on discussions between the Navy and NMFS, future monitoring 
should address the ICMP top-level goals through a collection of 
specific regional and ocean basin studies based on scientific 
objectives. Monitoring would follow the strategic planning process and 
conclusions from adaptive management review by shifting from applying 
quantitative effort-based metrics, and instead demonstrating progress 
on the goals of specific scientific monitoring questions. The adaptive 
management process and reporting requirements would serve as the basis 
for evaluating performance and compliance, primarily considering the 
quality of the work and results produced, as well as peer review and 
publications, and public dissemination of information, reports, and 
data. The strategic planning process would be used to set intermediate 
scientific objectives, identify potential species of interest at a 
regional scale, and evaluate and select specific monitoring projects to 
fund or continue supporting for a given fiscal year. The strategic 
planning process would also address relative investments to different 
range complexes based on goals across all range complexes, and 
monitoring would leverage multiple techniques for data acquisition and 
analysis whenever possible.
    The Scientific Advisory Group (SAG) confirmed the Navy/NMFS 
decision made in 2009 that because so little is known about species 
occurrence in this area, the priority for the MIRC should be 
establishing basic marine mammal occurrence. Passive acoustic 
monitoring, small boat surveys, biopsy sampling, satellite tagging, and 
photo-identification are all appropriate methods for evaluating marine 
mammal occurrence and abundance in the MITT Study Area. Fixed acoustic 
monitoring and development of local expertise ranked highest among the 
SAG's recommended monitoring methods for the area. There is an 
especially high level of return for monitoring around the Mariana 
Islands because so little is currently known about this region. 
Specific monitoring efforts would result from future Navy/NMFS 
monitoring program management.
    A more detailed description of the Navy's planned projects starting 
in 2015 (and some continuing from previous years) is available at the 
Navy's Marine Species Monitoring web portal: http://www.navymarinespeciesmonitoring.us/. The Navy will update the status of 
its monitoring program and funded projects through their Marine Species 
Monitoring web portal. NMFS will provide one public comment period on 
the Navy's monitoring program during the 5-year regulations. At this 
time, the public will have an opportunity (likely in the second or 
third year) to comment specifically on the Navy's MITT monitoring 
projects and data collection

[[Page 46138]]

to date, as well as planned projects for the remainder of the 
regulations.
    Through the adaptive management process (including annual 
meetings), the Navy will coordinate with NMFS and the Marine Mammal 
Commission (Commission) to review and provide input for projects that 
will meet the scientific objectives that are used to guide development 
of individual monitoring projects. The adaptive management process will 
continue to serve as the primary venue for both NMFS and the Commission 
to provide input on the Navy's monitoring program, including ongoing 
work, future priorities, and potential new projects. The Navy will 
continue to submit annual monitoring reports to NMFS as part of the 
MITT rulemaking and LOA requirements. Each annual report will contain a 
section describing the adaptive management process and summarize the 
Navy's anticipated monitoring projects for the next reporting year. 
Following annual report submission to NMFS, the final rule language 
mandates a 3-month NMFS review prior to each report being finalized. 
This will provide ample time for NMFS and the Commission to comment on 
the next year's planned projects as well as ongoing regional projects 
or proposed new starts. Comments will be received by the Navy prior to 
the annual adaptive management meeting to facilitate a meaningful and 
productive discussion. NMFS and the Commission will also have the 
opportunity for involvement at the annual monitoring program science 
review meetings and/or regional Scientific Advisory Group meetings. 
This will help NMFS and the Commission stay informed and understand the 
scientific considerations and limitations involved with planning and 
executing various monitoring projects.

Ongoing Navy Research

    The Navy is one of the world's leading organizations in assessing 
the effects of human activities on the marine environment, and provides 
a significant amount of funding and support to marine research, outside 
of the monitoring required by their incidental take authorizations. 
They also develop approaches to ensure that these resources are 
minimally impacted by current and future Navy operations. Navy 
scientists work cooperatively with other government researchers and 
scientists, universities, industry, and non-governmental conservation 
organizations in collecting, evaluating, and modeling information on 
marine resources, including working towards a better understanding of 
marine mammals and sound. From 2004 to 2014, the Navy has provided over 
$250 million for marine species research. The Navy sponsors 70 percent 
of all U.S. research concerning the effects of human-generated sound on 
marine mammals and 50 percent of such research conducted worldwide. 
Major topics of Navy-supported marine species research directly 
applicable to proposed activities within the MITT Study Area include 
the following:
     Better understanding of marine species distribution and 
important habitat areas;
     Developing methods to detect and monitor marine species 
before, during, and after training and testing activities;
     Better understanding the impacts of sound on marine 
mammals, sea turtles, fish, and birds; and
     Developing tools to model and estimate potential impacts 
of sound.
    It is imperative that the Navy's research and development (R&D) 
efforts related to marine mammals are conducted in an open, transparent 
manner with validated study needs and requirements. The goal of the 
Navy's R&D program is to enable collection and publication of 
scientifically valid research as well as development of techniques and 
tools for Navy, academic, and commercial use. The two Navy 
organizations that account for most funding and oversight of the Navy 
marine mammal research program are the Office of Naval Research (ONR) 
Marine Mammals and Biology Program, and the Office of the Chief of 
Naval Operations (CNO) Energy and Environmental Readiness Division 
(N45) Living Marine Resources (LMR) Program. The primary focus of these 
programs has been on understanding the effects of sound on marine 
mammals, including physiological, behavioral and ecological effects.
    The ONR Marine Mammals and Biology Program supports basic and 
applied research and technology development related to understanding 
the effects of sound on marine mammals, including physiological, 
behavioral, ecological, and population-level effects. Current program 
thrusts include:
     Monitoring and detection;
     Integrated ecosystem research including sensor and tag 
development;
     Effects of sound on marine life including hearing, 
behavioral response studies, diving and stress physiology, and 
Population Consequences of Acoustic Disturbance (PCAD); and
     Models and databases for environmental compliance.
    To manage some of the Navy's marine mammal research programmatic 
elements, OPNAV N45 developed in 2011 a Living Marine Resources (LMR) 
Research and Development Program (www.lmr.namy.mil). The mission of the 
LMR program is to develop, demonstrate, and assess information and 
technology solutions to protect living marine resources by minimizing 
the environmental risks of Navy at-sea training and testing activities 
while preserving core Navy readiness capabilities. This mission is 
accomplished by:
     Improving knowledge of the status and trends of marine 
species of concern and the ecosystems of which they are a part;
     Developing the scientific basis for the criteria and 
thresholds to measure the effects of Navy generated sound;
     Improving understanding of underwater sound and sound 
field characterization unique to assessing the biological consequences 
resulting from underwater sound (as opposed to tactical applications of 
underwater sound or propagation loss modeling for military 
communications or tactical applications); and
     Developing technologies and methods to monitor and, where 
possible, mitigate biologically significant consequences to living 
marine resources resulting from naval activities, emphasizing those 
consequences that are most likely to be biologically significant.
    The program is focused on three primary objectives that influence 
program management priorities and directly affect the program's success 
in accomplishing its mission:
    1. Collect, Validate, and Rank R&D Needs: Expand awareness of R&D 
program opportunities within the Navy marine resource community to 
encourage and facilitate the submittal of well-defined and appropriate 
needs statements.
    2. Address High Priority Needs: Ensure that program investments and 
the resulting projects maintain a direct and consistent link to the 
defined user needs.
    3. Transition Solutions and Validate Benefits: Maximize the number 
of program-derived solutions that are successfully transitioned to the 
Fleet and system commands.
    The LMR program primarily invests in the following areas:
     Developing Data to Support Risk Threshold Criteria;
     Improved Data Collection on Protected Species, Critical 
Habitat within Navy Ranges;

[[Page 46139]]

     New Monitoring and Mitigation Technology Demonstrations;
     Database and Model Development; and
     Education and Outreach, Emergent Opportunities.
    LMR currently supports the Marine Mammal Monitoring on Ranges 
program at the Pacific Missile Range Facility on Kauai and, along with 
ONR, the multi-year Southern California Behavioral Response Study 
(http://www.socal-brs.org). This type of research helps in 
understanding the marine environment and the effects that may arise 
from underwater noise in oceans.

Adaptive Management

    Although substantial improvements have been made in our 
understanding of the effects of Navy training and testing activities 
(e.g., sonar, underwater detonations) on marine mammals, the science in 
this field is evolving fairly quickly. These circumstances make the 
inclusion of an adaptive management component both valuable and 
necessary within the context of 5-year regulations.
    The reporting requirements associated with this rule are designed 
to provide NMFS with monitoring data from the previous year to allow 
NMFS to consider whether any changes are appropriate. NMFS and the Navy 
would meet to discuss the monitoring reports, Navy R&D developments, 
and current science and whether mitigation or monitoring modifications 
are appropriate. The use of adaptive management allows NMFS to consider 
new information from different sources to determine (with input from 
the Navy regarding practicability) on an annual or biennial basis if 
mitigation or monitoring measures should be modified (including 
additions or deletions). Mitigation measures could be modified if new 
data suggests that such modifications would have a reasonable 
likelihood of reducing adverse effects to marine mammals and if the 
measures are practicable.
    The following are some of the possible sources of applicable data 
to be considered through the adaptive management process: (1) Results 
from monitoring and exercises reports, as required by MMPA 
authorizations; (2) compiled results of Navy funded R&D studies; (3) 
results from specific stranding investigations; (4) results from 
general marine mammal and sound research; and (5) any information which 
reveals that marine mammals may have been taken in a manner, extent, or 
number not authorized by these regulations or subsequent LOA.

Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' Effective reporting is 
critical both to compliance as well as ensuring that the most value is 
obtained from the required monitoring. NMFS described the proposed Navy 
reporting requirements in the proposed rule (79 FR 15388, March 19, 
2014; page 15426). Reports from individual monitoring events, results 
of analyses, publications, and periodic progress reports for specific 
monitoring projects will be posted to the Navy's Marine Species 
Monitoring web portal: http://www.navymarinespeciesmonitoring.us and 
NMFS' Web site: http://www.nmfs.noaa.gov/pr/permits/incidental/. There 
are several different reporting requirements that are further detailed 
in the regulatory text at the end of this document and summarized 
below.

General Notification of Injured or Dead Marine Mammals

    Navy personnel would ensure that NMFS (the appropriate Regional 
Stranding Coordinator) is notified immediately (or as soon as clearance 
procedures allow) if an injured or dead marine mammal is found during 
or shortly after, and in the vicinity of, any Navy training exercise 
utilizing mid-frequency active sonar, high-frequency active sonar, or 
underwater explosive detonations. The Navy would provide NMFS with 
species identification or a description of the animal(s), the condition 
of the animal(s) (including carcass condition if the animal is dead), 
location, time of first discovery, observed behaviors (if alive), and 
photographs or video (if available). The MITT Stranding Response Plan 
contains further reporting requirements for specific circumstances 
(http://www.nmfs.noaa.gov/pr/permits/incidental/).

Vessel Strike

    Since the proposed rule, NMFS has added the following language to 
address monitoring and reporting measures specific to vessel strike. 
Most of this language comes directly from the Stranding Response Plan. 
This section has also been included in the regulatory text at the end 
of this document. Vessel strike during Navy training and testing 
activities in the Study Area is not anticipated; however, in the event 
that a Navy vessel strikes a whale, the Navy shall do the following:
    Immediately report to NMFS (pursuant to the established 
Communication Protocol) the:
     Species identification (if known);
     Location (latitude/longitude) of the animal (or location 
of the strike if the animal has disappeared);
     Whether the animal is alive or dead (or unknown); and
     The time of the strike.
    As soon as feasible, the Navy shall report to or provide to NMFS, 
the:
     Size, length, and description (critical if species is not 
known) of animal;
     An estimate of the injury status (e.g., dead, injured but 
alive, injured and moving, blood or tissue observed in the water, 
status unknown, disappeared, etc.);
     Description of the behavior of the whale during event, 
immediately after the strike, and following the strike (until the 
report is made or the animal is no longer sighted);
     Vessel class/type and operational status;
     Vessel length;
     Vessel speed and heading; and
     To the best extent possible, obtain a photo or video of 
the struck animal, if the animal is still in view.
    Within 2 weeks of the strike, provide NMFS:
     A detailed description of the specific actions of the 
vessel in the 30-minute timeframe immediately preceding the strike, 
during the event, and immediately after the strike (e.g., the speed and 
changes in speed, the direction and changes in direction, other 
maneuvers, sonar use, etc., if not classified);
     A narrative description of marine mammal sightings during 
the event and immediately after, and any information as to sightings 
prior to the strike, if available; and use established Navy shipboard 
procedures to make a camera available to attempt to capture photographs 
following a ship strike.
    NMFS and the Navy will coordinate to determine the services the 
Navy may provide to assist NMFS with the investigation of the strike. 
The response and support activities to be provided by the Navy are 
dependent on resource availability, must be consistent with military 
security, and must be logistically feasible without compromising Navy 
personnel safety. Assistance requested and provided may vary based on 
distance of strike from shore, the nature of the vessel that hit the 
whale, available nearby Navy resources, operational and installation 
commitments, or other factors.

[[Page 46140]]

Annual Monitoring Reports

    As noted above, reports from individual monitoring events, results 
of analyses, publications, and periodic progress reports for specific 
monitoring projects would be posted to the Navy's Marine Species 
Monitoring web portal and NMFS' Web site as they become available. 
Progress and results from all monitoring activity conducted within the 
MITT Study Area, as well as required Major Training Exercise activity, 
would be summarized in an annual report. A draft report would be 
submitted either 90 days after the calendar year or 90 days after the 
conclusion of the monitoring year, date to be determined by the 
adaptive management review process. In the past, each annual report has 
summarized data for a single year. At the Navy's suggestion, future 
annual reports would take a cumulative approach in that each report 
will compare data from that year to all previous years. For example, 
the third annual report will include data from the third year and 
compare it to data from the first and second years. This will provide 
an ongoing cumulative look at the Navy's annual monitoring and exercise 
and testing reports and eliminate the need for a separate comprehensive 
monitoring and exercise summary report at the end of the 5-year period.

Annual Exercise and Testing Reports

    The Navy shall submit preliminary reports detailing the status of 
authorized sound sources within 21 days after the anniversary of the 
date of issuance of the LOA. The Navy shall submit detailed reports 3 
months after the anniversary of the date of issuance of the LOA. The 
detailed annual reports shall contain information on Major Training 
Exercises (MTE), Sinking Exercise (SINKEX) events, and a summary of 
sound sources used, as described below. The analysis in the detailed 
reports will be based on the accumulation of data from the current 
year's report and data collected from previous reports.

Comments and Responses

    On March 19, 2014 (79 FR 15388), NMFS published a proposed rule in 
response to the Navy's request to take marine mammals incidental to 
training and testing activities in the MITT Study Area and requested 
comments, information, and suggestions concerning the request. During 
the 45-day public comment period, NMFS received comments from the 
Marine Mammal Commission, private citizens, and an elected official 
(Senator Vicente (ben) C. Pangelinan, 32nd Guam legislature). Comments 
specific to section 101(a)(5)(A) of the MMPA and NMFS' analysis of 
impacts to marine mammals are summarized, sorted into general topic 
areas, and addressed below and/or throughout the final rule. Comments 
specific to the MITT EIS/OEIS, which NMFS participated in developing as 
a cooperating agency and adopted, or that were also submitted to the 
Navy during the MITT DEIS/OEIS public comment period are addressed in 
Appendix E (Public Participation) of the FEIS/OEIS. The Natural 
Resources Defense Council (NRDC) did not submit comments specific to 
the proposed MITT rulemaking; however, NRDC has indicated their full 
endorsement of the comments and management recommendations submitted on 
the MITT DEIS/OEIS by the Commonwealth of the Northern Mariana Islands 
(Governor Eloy S. Inos). Those comments are addressed in Appendix E of 
the FEIS/OEIS and are considered by NMFS and the Navy in the context of 
both this rulemaking and related NEPA compliance. Comments submitted by 
Governor Inos that are most applicable to this rulemaking include 
recommended mitigation areas and are addressed below. Last, some 
commenters presented technical comments on the general behavioral risk 
function that are largely identical to those posed during the comment 
period for proposed rules for the Hawaii Range Complex (HRC), Atlantic 
Fleet Active Sonar Training (AFAST), Atlantic Fleet Training and 
Testing (AFTT), and Hawaii-Southern California Training and Testing 
(HSTT) study areas, predecessors to the MITT rule. The behavioral risk 
function remains unchanged since then, and here we incorporate our 
responses to those initial technical comments (74 FR 1455, Acoustic 
Threshold for Behavioral Harassment section, page 1473; 74 FR 4844, 
Behavioral Harassment Threshold section, page 4865; 78 FR 73010, 
Acoustic Thresholds section, page 73038; 78 FR 78106, Acoustic 
Thresholds section, page 78129). Full copies of the comment letters may 
be accessed at http://www.regulations.gov.

Marine Mammal Density Estimates

    Comment 1: The Commission recommended that NMFS require the Navy to 
(1) account for uncertainty in extrapolated density estimates for all 
species by using the upper limit of the 95% confidence interval or the 
arithmetic mean plus two standard deviations and (2) then re-estimate 
the numbers of takes accordingly.
    Response 1: The Navy coordinated with both NMFS' Pacific Islands 
Fisheries Science Center (PIFSC) and Southwest Fisheries Science Center 
(SWFSC) to identify the best available density estimates for marine 
mammals occurring in the Study Area. In all cases, a conservative 
(i.e., greater) estimate was selected. The Navy's use of a mean density 
estimate is consistent with the approach taken by NMFS to estimate and 
report the populations of marine mammals in their Stock Assessment 
Reports and the estimated mean is thus considered the ``best available 
data.'' Adjusting the mean estimates as suggested would result in 
unreasonable measures, particularly given the very high coefficient of 
variation (CV) associated with most marine mammal density estimates. 
Further, the Navy's acoustic model includes conservative estimates of 
all parameters (e.g., assumes that the animals do not move 
horizontally, assumes animals are always head-on to the sound source so 
that they receive the maximum amount of energy, etc.) resulting in a 
more conservative (i.e., greater) assessment of potential impacts.

Mitigation, Monitoring, and Reporting

    Comment 2: Governor Eloy S. Inos (Commonwealth of the Northern 
Mariana Islands [CNMI]) recommended (via comments submitted on the MITT 
DEIS/OEIS) specific geographic marine mammal mitigation areas--or 
habitat protection areas--to be avoided by all Navy sonar and 
explosives training and testing activities. These include near-island 
habitat in the vicinity of the islands of the CNMI, landward of the 
3,500 m isobath (based on concentrations of insular populations of 
odontocetes within the 3,500 m isobath around the Hawaiian Islands); 
and from the West Mariana Ridge (a chain of conical seamounts 
paralleling 145 to 170 km west of the Mariana Islands) to the 3,500 m 
isobaths around the ridge, between roughly 13[deg] and 18[deg] N where 
two beaked whale sightings were made during a Navy line-transect survey 
in 2007, passive acoustic data acquired during that same survey showed 
multiple detections of short-finned pilot whales around the ridgeline, 
and satellite tagging efforts showed use of the ridge by at least one 
false killer whale tagged off Rota (Hill et al., 2013).
    Response 2: Under section 101(a)(5)(A) of the MMPA, NMFS must set 
forth the ``means of effecting the least practical adverse impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance.'' The 
NDAA amended the

[[Page 46141]]

MMPA as it relates to military-readiness activities (which these Navy 
activities are) and the incidental take authorization process such that 
``least practicable adverse impact'' shall include consideration of 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the ``military readiness activity.'' Therefore, as 
discussed earlier in the Mitigation section, in making a determination 
of ``least practicable adverse impact,'' NMFS considers the likely 
benefits of a mitigation measures being considered to affected species 
or stocks and their habitat, as well as the likely effect of those 
measures on personnel safety, practicality of implementation, and the 
impact on the effectiveness of the military readiness activity.
    With respect to the effectiveness of area limitations, temporal 
(e.g., seasonal) or geographic limitations (time/area limitations) are 
a direct and effective means of reducing adverse impacts to marine 
mammals. By reducing the overlap in time and space of the known 
concentrations of marine mammals and the acoustic footprint associated 
with the thresholds for the different types of take (either at all 
times and places where animals are concentrated, or times and places 
where they are concentrated for specifically important behaviors (such 
as reproduction or feeding)), the amount of take can be reduced. It is 
most effective when these measures are used carefully at times and 
places where their effects are relatively well known. For example, if 
there is credible evidence that concentrations of marine mammals are 
known to be high at a specific place or during a specific time of the 
year (such as the high densities of humpback whales delineated on the 
Mobley map in the HRC, or North Atlantic right whale critical habitat 
on the east coast), then these seasonal or geographic exclusions or 
limitations may be appropriate. However, if marine mammals are known to 
prefer certain types of areas (as opposed to specific areas) for 
certain functions, such as beaked whale use of seamounts or marine 
mammal use of productive areas like cyclonic eddies, which means that 
they may or may not be present at any specific time, it is less 
effective to require avoidance or limited use of the area because they 
may not be present.
    The Governor's recommendation that the Navy exclude sonar and 
explosives training and testing in the vicinity of the islands of the 
CNMI landward of the 3,500 m isobaths is based on the fact that in 
Hawaii insular populations of odontocetes are generally concentrated on 
important near-island habitat within the 3,500 m isobaths. However, 
there is nothing to suggest that a similar isobath represents the 
delineation of important near-island habitat for concentrations of 
marine mammals around the islands of the CNMI. In fact, satellite tag 
deployment data from cetacean (short-finned pilot whales, false killer 
whales, rough-toothed dolphins, bottlenose dolphins, and melon-headed 
whales) surveys in the waters surrounding Guam and the CNMI during 
2010-2014, conducted by the Pacific Islands Fisheries Science Center 
(PIFSC) in partnership with the Navy, showed that multiple tagged 
species utilized the areas far offshore beyond the 3,500 m isobath 
(Hill et al., 2014). These findings are corroborated by line transect 
surveys conducted by Fulling et al. (2011), which document multiple 
encounters and wide distribution of bottlenose dolphins, rough-toothed 
dolphins, pantropical spotted dolphins, false killer whales, and sperm 
whales far offshore of Guam and the CNMI at depths up to 9,874 m. NMFS, 
therefore, does not consider the near-island waters landward of the 
3,500 m isobaths around the islands of the CNMI an appropriate time/
area limitation for training and testing activities in the Study Area.
    Regarding the Governor's recommendation that the Navy not conduct 
sonar and explosives training and testing from the West Mariana Ridge 
to the 3,500 m isobath around the ridge, the relatively limited data 
cited by the Governor is not suggestive of high concentrations of 
marine mammals or marine mammal species (i.e., two beaked whales, three 
short-finned pilot whales, one false killer whale) specific to this 
ridge. In fact, satellite tagging efforts by PIFSC indicated the vast 
majority of tagged false killer whales occurred well beyond, and east 
of, the West Mariana Ridge ridgeline (Hill et al., 2014 and 2015). And 
while the Navy's line-transect survey and passive acoustic monitoring 
conducted in 2007 noted the presence of a few individuals of short-
finned pilot whales (and beaked whales) along portions of the West 
Mariana Ridge, PIFSC telemetry data analyzed by Hill et al. (2015) 
indicate a preference away from the ridge and closer to the near-island 
waters around Guam (though not exclusively so). NMFS recognizes the 
generally biologically productive nature of some ridges and seamounts; 
however, there are no data to suggest that important or species-
specific habitat (rookeries, reproductive, feeding) exists along the 
West Mariana Ridge or within the 3,500 m isobath around the ridge.
    In addition to NMFS' consideration of the effectiveness of the 
time/area restrictions recommended by Governor Eloy S. Inos, the Navy 
has provided in the MITT FEIS/OEIS the following specific reasons 
explaining why these types of geographic restrictions or limitations 
are considered impracticable for the Navy:
     Broad Coastal Restrictions (e.g., around entire islands) 
Based on Distances from Isobaths or Shorelines--Avoiding locations for 
training and testing activities within the Study Area based on wide-
scale distances from isobaths or the shoreline for the purpose of 
mitigation would be impractical with regard to implementation of 
military readiness activities, result in unacceptable impact on 
readiness, and would not be an effective means of mitigation, and would 
increase safety risks to personnel. Training in shallower water is an 
essential component to maintaining military readiness. Sound propagates 
differently in shallower water and operators must learn to train in 
this environment. Additionally, submarines have become quieter through 
the use of improved technology and have learned to hide in the higher 
ambient noise levels of the shallow waters of coastal environments. In 
real world events, it is highly likely Sailors would be working in, and 
therefore must train in, these types of areas. The littoral waterspace 
is also the most challenging area to operate in due to a diverse 
acoustic environment. It is not realistic or practicable to refrain 
from training in the areas that are the most challenging and 
operationally important. Operating in shallow water is essential in 
order to provide realistic training on real world combat conditions 
with regard to shallow water sound propagation.
     Avoiding Locations Based on Bathymetry--Requiring training 
and testing to avoid large areas that encompass a large portion of a 
particular bathymetric conditions (e.g., high-relief seamounts such as 
those that comprise the West Mariana Ridge) within a designated Range 
Complex or study area for the purpose of mitigation would increase 
safety risks to personnel and result in unacceptable impact on 
readiness. Limiting training and testing (including the use of sonar 
and other active acoustic sources or explosives) to avoid steep or 
complex bathymetric features (e.g., seamounts) would reduce the realism 
of the military readiness activity. Systems must be tested in a variety 
of bathymetric conditions to ensure functionality and accuracy in a 
variety of environments. Sonar operators need to train as they would

[[Page 46142]]

operate during real world combat situations. Because real world combat 
situations include diverse bathymetric conditions, Sailors must be 
trained to handle bottom bounce, sound passing through changing 
currents, eddies, or across changes in ocean temperature, pressure, or 
salinity. Training with reduced realism would alter Sailors' abilities 
to effectively operate in a real world combat situation, thereby 
resulting in an unacceptable increased risk to personnel safety and the 
sonar operator's ability to achieve mission success.
    A more detailed discussion can be found in Section 5.3.4.1 of the 
MITT FEIS/OEIS.
    In conclusion, NMFS has considered the time/area restrictions 
recommended by Governor Eloy S. Inos and has determined that requiring 
those measures would not reduce adverse effects to marine mammal 
populations or stocks or provide additional protection of marine mammal 
populations or stocks in the Study Area beyond those mitigation 
measures already proposed in the MITT EIS/OEIS and in this final rule 
(see Mitigation section above). Further, NMFS has considered the Navy's 
conclusion that such limitations would impose an increased safety risk 
to personnel, an unacceptable impact on the effectiveness of training 
and testing activities that would affect military readiness, and an 
impractical burden with regard to implementation (This process is 
further detailed in Section 5.2.3 of the MITT FEIS/OEIS).
    Comment 3: Senator Vicente (ben) C. Pangelinan (32nd Guam 
Legislature) expressed concerns with the effectiveness of the 
mitigation measures (e.g., Lookouts) outlined in the proposed rule. The 
Senator also questioned whether or not animals exposed to Navy sound 
sources will return to their usual locations.
    Response 3: NMFS has carefully evaluated the Navy's proposed suite 
of mitigation measures and considered a broad range of other measures 
(including those recommended during the proposed rule public comment 
period) in the context of ensuring that NMFS prescribes the means of 
effecting the least practicable adverse impact on the affected marine 
mammal species and stocks and their habitat. Based on our evaluation of 
the Navy's proposed measures, as well as other measures considered by 
NMFS or recommended by the public, NMFS has determined that the Navy's 
proposed mitigation measures (especially when the adaptive management 
component is taken into consideration (see Adaptive Management, 
below)), along with the additions detailed in the Mitigation section 
above, are adequate means of effecting the least practicable adverse 
impacts on marine mammals species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, while also considering personnel safety, practicality of 
implementation, and impact on the effectiveness of the military 
readiness activity.
    Regarding Navy Lookouts, Lookouts are a vital aspect of the 
strategy for limiting potential impacts from Navy activities. Lookouts 
are qualified and experienced observers of the marine environment. All 
Lookouts take part in Marine Species Awareness Training so that they 
are better prepared to spot marine mammals. Detailed information on the 
Navy's Marine Species Awareness Training program, which speaks to 
qualifications and training, is also provided in Chapter 5 of the MITT 
FEIS/OEIS. Their primary duty is to detect objects in the water, 
estimate the distance from the ship, and identify them as any number of 
inanimate or animate objects that are significant to a Navy activity or 
as a marine mammal so that the mitigation measure can be implemented. 
Lookouts are on duty at all times, day and night, when a ship or 
surfaced submarine is moving through the water. Lookouts are used 
continuously, throughout the duration of activities that involve the 
following: Active sonar, Improved Extended Echo Ranging (IEER) 
sonobuoys, anti-swimmer grenades, positive control firing devices, 
timedelay firing devices, gunnery exercises (surface target), missile 
exercises (surface target), bombing exercises, torpedo (explosive) 
testing, sinking exercises, at-sea explosives testing, vessels 
underway, towed in-water devices (from manned platforms), and non-
explosive practice munitions. Visual detections of marine mammals would 
be communicated immediately to a watch station for information 
disseminations and appropriate mitigation action. The Navy will use 
passive acoustic monitoring to supplement visual observations by 
Lookouts during IEER sonobuoy activities, explosive sonobuoys using 
0.6-2.5 pound (lb) net explosive weight, torpedo (explosive) testing, 
and sinking exercises, to detect marine mammal vocalizations. Passive 
acoustic detections will be reported to Lookouts to increase vigilance 
of the visual observation. NMFS has carefully considered Navy's use of 
Lookouts and determined that in combination with the Stranding Response 
Plans, and the other mitigation measures identified, the Navy's 
mitigation plan will effect the least practicable adverse impacts on 
marine mammal species or stocks and their habitat.
    There are numerous studies which document the return of marine 
mammals (both odontocetes and mysticetes) following displacement of an 
individual (i.e., short-term avoidance) from an area as a result of the 
presence of a sound (Bowles et al., 1994; Goold, 1996; 1998; Stone et 
al., 2000; Morton and Symonds, 2002; Gailey et al., 2007; Claridge and 
Durban 2009; Moretti et al., 2009; McCarthy et al., 2011; Tyack et al., 
2011). These studies are referenced and discussed in both the Navy's 
LOA application (Chapter 6) and the proposed rule (79 FR 15403, March 
19, 2014), as well as in the Analysis and Negligible Impact 
Determination section of this final rule.
    Comment 4: Senator Vicente (ben) C. Pangelinan (32nd Guam 
Legislature) expressed concerns with the Navy's inability to mitigate 
for onset of TTS during every activity. Other commenters (e.g., 
Governor Eloy S. Inos, CNMI) on the MITT DEIS/OEIS expressed similar 
concerns regarding the size of recommended mitigation zones, 
particularly those proposed for MF1 sonar system activities in which 
the Governor recommended the Navy ``establish a wider buffer, to the 
maximum extent practicable.''
    Response 4: As discussed in the proposed rule (79 FR 15388, March 
19, 2014), TTS is a type of Level B harassment. In the Estimated Take 
of Marine Mammal section, we quantify the effects that might occur from 
the specific training and testing activities that the Navy proposes in 
the MITT Study Area, which includes the number of takes by Level B 
harassment (behavioral harassment, acoustic masking and communication 
impairment, and TTS). Through this rulemaking, NMFS has authorized the 
Navy to take marine mammals by Level B harassment incidental to Navy 
training and testing activities in the MITT Study Area. In order to 
issue an ITA, we must set forth the ``permissible methods of taking 
pursuant to such activity, and other means of effecting the least 
practical adverse impact on such species or stock and its habitat, 
paying particular attention to rookeries, mating grounds, and areas of 
similar significance.'' We have determined that the mitigation measures 
implemented under this rule effect the least practical adverse impact 
on marine mammal species and stocks and their habitat.

[[Page 46143]]

    The Navy developed activity-specific mitigation zones based on the 
Navy's acoustic propagation model. Each recommended mitigation zone is 
intended to avoid or reduce the potential for onset of the lowest level 
of injury, PTS, out to the predicted maximum range. Mitigating to the 
predicted maximum range to PTS consequently also mitigates to the 
predicted maximum range to onset mortality (1 percent mortality), onset 
slight lung injury, and onset slight gastrointestinal tract injury, 
since the maximum range to effects for these criteria are shorter than 
for PTS. Furthermore, in most cases, the mitigation zone actually 
covers the TTS zone. In some instances, the Navy recommended mitigation 
zones are larger or smaller than the predicted maximum range to PTS 
based on the associated effectiveness and operational assessments 
presented in Section 5.2.3 of the MITT FEIS/OEIS. NMFS worked closely 
with the Navy in the development of the recommendations and carefully 
considered them prior to adopting them in this final rule. The 
mitigation zones contained in this final rule represent the maximum 
area the Navy can effectively observe based on the platform of 
observation, number of personnel that will be involved, and the number 
and type of assets and resources available. As mitigation zone sizes 
increase, the potential for reducing impacts decreases. For instance, 
if a mitigation zone increases from 1,000 to 4,000 yd. (914 to 3,658 
m), the area that must be observed increases sixteen-fold, which is not 
practicable. The mitigation measures contained in this final rule 
balance the need to reduce potential impacts with the Navy's ability to 
provide effective observations throughout a given mitigation zone. 
Implementation of mitigation zones is most effective when the zone is 
appropriately sized to be realistically observed. The Navy does not 
have the resources to maintain additional Lookouts or observer 
platforms that would be needed to effectively observe mitigation zones 
of increased size.
    Comment 5: The Commission recommended that NMFS require the Navy to 
provide the predicted average and maximum ranges for all impact 
criteria (i.e., behavioral response, TTS, PTS, onset slight lung 
injury, onset slight gastrointestinal injury, and onset mortality), for 
all activities (i.e., based on the activity category and representative 
source bins and include ranges for more than 1 ping), and for all 
functional hearing groups of marine mammals within MITT representative 
environments (including shallow-water nearshore areas).
    Response 5: The Navy discusses range to effects in Sections 
3.4.4.1.1 and 3.4.4.2.1 of the MITT FEIS/OEIS. The active acoustic 
tables in Section 3.4.4.1.1 illustrate the ranges to PTS, TTS, and 
behavioral response. The active acoustic tables for PTS and TTS show 
ranges for all functional hearing groups and the tables for behavioral 
response show ranges for low-, mid-, and high-frequency cetaceans. The 
active acoustic source class bins used to assess range to effects 
represent some of the most powerful sonar sources and are often the 
dominant source in an activity. The explosives table in Section 
3.4.4.2.1 illustrates the range to effects for onset mortality, onset 
slight lung injury, onset slight gastrointestinal tract injury, PTS, 
TTS, and behavioral response. The explosives table shows ranges for all 
functional hearing groups. The source class bins used for explosives 
range from the smallest to largest amount of net explosive weight. 
These ranges represent conservative estimates (i.e., longer ranges) 
based on the assumption that all impulses are 1-second in duration. In 
fact, most impulses are much shorter and contain less energy. 
Therefore, these ranges provide realistic maximum distances over which 
the specific effects would be possible.
    NMFS believes that these representative sources provide adequate 
information to analyze potential effects on marine mammals. Because the 
Navy conducts training and testing in a variety of environments having 
variable acoustic propagation conditions, variations in acoustic 
propagation conditions are considered in the Navy's acoustic modeling 
and the quantitative analysis of acoustic impacts.
    Average ranges to effect are provided in the MITT FEIS/OEIS to show 
the reader typical zones of impact around representative sources. As 
noted in the LOA application and MITT FEIS/OEIS, the ranges provided in 
the analysis sections (Section 6 of the LOA and Chapter 3 of the MITT 
FEIS/OEIS) are the average range to all effects for representative 
sources in a variety of environments (shallow and deep water). These 
are not nominal values for deep-water environments, as repeatedly 
asserted by the Commission.
    Comment 6: The Commission recommended that NMFS require the Navy to 
use passive and active acoustics to supplement visual monitoring during 
implementation of mitigation measures for all activities that could 
cause Level A harassment or mortality beyond those explosive activities 
for which passive acoustic monitoring was already proposed. 
Specifically, the Commission questioned why passive and active acoustic 
monitoring used during the Navy's Surveillance Towed Array Sensory 
System Low Frequency Active (SURTASS LFA) activities is not applied 
here.
    Response 6: The Navy requested Level A (injury) take of marine 
mammals for impulse and non-impulse sources during training and testing 
based on its acoustic analysis. While it is impractical for the Navy to 
conduct passive acoustic monitoring during all training and testing 
activities (due to lack of resources), the Navy has engineered the use 
of passive acoustic detection for monitoring purposes, taking into 
consideration where the largest impacts could potentially occur, and 
the effectiveness and practicability of installing or using these 
devices. The Navy will use passive acoustic monitoring to supplement 
visual observations during Improved Extended Echo Ranging (IEER) 
sonobuoy activities, explosive sonobuoys using 0.6-2.5 pound (lb) net 
explosive weight, torpedo (explosive) testing, and sinking exercises, 
to detect marine mammal vocalizations. However, it is important to note 
that passive acoustic detections do not provide range or bearing to 
detected animals, and therefore cannot provide locations of these 
animals. Passive acoustic detections will be reported to lookouts to 
increase vigilance of the visual observation.
    The active sonar system used by SURTASS LFA is unique to the 
platforms that use SURTASS LFA. Moreover, this system requires the 
platforms that carry SURTASS LFA to travel at very slow speeds for the 
system to be effective. For both of these reasons it is not possible 
for the Navy to use this system for the platforms analyzed in the MITT 
FEIS/OEIS.
    NMFS believes that the Navy's suite of mitigation measures (which 
include mitigation zones that exceed or meet the predicted maximum 
distance to PTS) will typically ensure that animals will not be exposed 
to injurious levels of sound. To date, the monitoring reports submitted 
by the Navy for MIRC (or the AFTT and HSTT Study Areas), do not show 
any evidence of injured marine mammals.
    Comment 7: The Commission recommended that NMFS require the Navy to 
use a second clearance category of 60 minutes for deep-diving species 
(i.e., beaked whales and sperm whales) if the animal has not been 
observed exiting the mitigation zone following shutdown of acoustic 
activities due to a marine mammal sighting.

[[Page 46144]]

    Response 7: NMFS does not concur with the Commission's 
recommendation that the Navy should use a second clearance category of 
60 minutes for deep-diving species for the following reasons:
     As described in the MITT FEIS/OEIS in Chapter 5 (Standard 
Operating Procedures, Mitigation, and Monitoring), a 30-minute wait 
period more than covers the average dive times of most marine mammals.
     The ability of an animal to dive longer than 30 minutes 
does not mean that it will always do so. Therefore, the 60-minute delay 
would only potentially add value in instances when animals had remained 
under water for more than 30 minutes.
     Navy vessels typically move at 10-12 knots (5-6 m/sec) 
when operating active sonar and potentially much faster when not. Fish 
et al. (2006) measured speeds of seven species of odontocetes and found 
that they ranged from 1.4-7.30 m/sec. Even if a vessel was moving at 
the slower typical speed associated with active sonar use, an animal 
would need to be swimming near sustained maximum speed for an hour in 
the direction of the vessel's course to stay within the safety zone of 
the vessel. Increasing the typical speed associated with active sonar 
use would further narrow the circumstances in which the 60-minute delay 
would add value.
     Additionally, the times when marine mammals are deep-
diving (i.e., the times when they are under the water for longer 
periods of time) are the same times that a large portion of their 
motion is in the vertical direction, which means that they are far less 
likely to keep pace with a horizontally moving vessel.
     Given that, the animal would need to have stayed in the 
immediate vicinity of the sound source for an hour, and considering the 
maximum area that both the vessel and the animal could cover in an 
hour, it is improbable that this would randomly occur. Moreover, 
considering that many animals have been shown to avoid both acoustic 
sources and ships without acoustic sources, it is improbable that a 
deep-diving cetacean (as opposed to a dolphin that might bow ride) 
would choose to remain in the immediate vicinity of the source.
    In summary, NMFS believes that it is unlikely that a single 
cetacean would remain in the safety zone of a Navy sound source for 
more than 30 minutes, and therefore disagrees with the Commission that 
a second clearance category of 60 minutes for deep-diving species is 
necessary.
    Comment 8: The Commission recommended that NMFS require the Navy to 
(1) provide the range to effects for all impact criteria (i.e., 
behavioral response, TTS, PTS, onset slight lung injury, onset slight 
gastrointestinal injury, and onset mortality) for underwater 
detonations that involve time-delay firing devices based on sound 
propagation in shallow-water nearshore environments for the associated 
marine mammal functional hearing groups and (2) use those data coupled 
with the maximum charge weight and average swim speed of the fastest 
group of marine mammals as the basis for the mitigation zone for 
underwater detonations that involve time-delay firing devices. If NMFS 
does not require the Navy to adjust its mitigation zones, then it 
should authorize the numbers of takes for Level A harassment and 
mortality based on the possibility that marine mammals could be present 
in the mitigation zone when the explosives detonate and based on 
updated, more realistic swim speeds.
    Response 8: As shown in the LOA application (Table 11-1) and MITT 
FEIS/OEIS (Table 5.3-2), which provide ranges to effects for explosive 
sources used in the MITT Study Area, the maximum range to PTS effects 
for a 20 lb. NEW charge used with this activity is 102 yd. (93 m), and 
the average range to TTS effects is 407 yd. (372 m). A 20 lb. NEW 
charge is the largest used in Mine Neutralization Activities Using 
Diver-Placed Time-Delay Firing Devices. These ranges to effects for 
explosive sources represent conservative estimates assuming all 
impulses (i.e., explosions) are 1 second in duration. In fact, most 
impulses from explosions are much less than 1 second in duration and 
therefore contain much less energy than the amount of energy used to 
produce the estimated ranges to effects.
    The proposed mitigation zone of 1,000 yd. (914 m) is well beyond 
the estimated range to effects and is overprotective for mine 
neutralization activities using diver-placed time-delay firing devices. 
The ranges to onset mortality, onset slight lung injury, and onset 
gastrointestinal injury are all less than the range to PTS level 
effects and would be well within the mitigation zone. As described in 
Chapter 5, Section 5.3.1.2.2.5 (Mine Neutralization Activities Using 
Diver-Placed Time-Delay Firing Devices) of the MITT FEIS/OEIS, four 
Lookouts and two small boats represent the maximum level of effort that 
the Navy can commit for observing the mitigation zone for this activity 
given the number of personnel and assets available. In addition to the 
four lookouts, divers and aircrew (if aircraft are involved in the 
activity) would also serve as lookouts in addition to conducting their 
regular duties to support the activity. As noted by Navy in previous 
responses to comments on other Navy training and testing EIS/OEISs, the 
mitigation zone is sufficiently large to account for a portion of the 
distance that a marine mammal could potentially travel during the time 
delay based on a reasonable assumption of marine mammal swim speeds.
    The supplemental information presented by the Commission to support 
the comment points out that Table 6-12 in the LOA application does not 
present ranges to effects for Bin E6 (up to a 20 lb. NEW). As stated in 
the table heading, the table is intended to be representative and is 
not specific to the MITT Study Area; therefore not all bins are 
included. However, the table shows that the proposed mitigation zone of 
1,000 yd. (914 m) would also be protective against injury exposures 
from explosives in Bin E7 (21 lb. to 60 lb. NEW).
    Furthermore, as a result of essential fish habitat consultations 
with NMFS, the Navy has agreed to maintain the maximum NEW charge used 
at the Outer Apra Harbor Underwater Detonation Site at 10 lb. NEW and 
not to increase the maximum NEW to 20 lb., as proposed under 
Alternatives 1 and 2 of the FEIS/OEIS and in the Navy's LOA 
application. A maximum charge of 20 lb. NEW is still proposed for use 
at the Agat Bay Mine Neutralization Site, which is farther from shore 
and in deeper water. The maximum charge at the Piti Floating Mine 
Neutralization Site will also remain at 10 lb. NEW.
    Comment 9: The Commission recommended that NMFS require the Navy to 
submit a proposed monitoring plan for the MITT Study Area for public 
review and comment prior to issuance of final regulations.
    Response 9: NMFS provided an overview of the Navy's Integrated 
Comprehensive Monitoring Program (ICMP) in the proposed rule (79 FR 
15388, March 19, 2014). While the ICMP does not specify actual 
monitoring field work or projects, it does establish top level goals 
that have been developed by the Navy and NMFS. As explained in the 
proposed rule, detailed and specific studies will be developed as the 
ICMP is implemented and funding is allocated.
    Since the proposed rule was published, the Navy has provided a more 
detailed short-term plan for the first year of the rule. Monitoring in 
2015 will be a combination of previously funded FY-14 ``carry-over'' 
projects from Phase I and new FY-15 project starts under the vision for 
Phase II monitoring. A more detailed description of the Navy's planned 
projects starting

[[Page 46145]]

in 2015 (and some continuing from previous years) are available on 
NMFS' Web site (www.nmfs.noaa.gov/pr/permits/incidental/).
    Additionally, NMFS will provide one public comment period on the 
Navy's monitoring program during the 5-year regulations. At this time, 
the public will have an opportunity (likely in the second year) to 
comment specifically on the Navy's MITT monitoring projects and data 
collection to date, as well as planned projects for the remainder of 
the regulations. The public also has the opportunity to review the 
Navy's monitoring reports, which are posted and available for download 
every year from the Navy's marine species monitoring Web site: http://www.navymarinespeciesmonitoring.us/. Details of already funded MITT 
monitoring projects and new start projects are available through the 
Navy's marine species monitoring Web site: http://www.navymarinespeciesmonitoring.us/. The Navy will update the status of 
their monitoring projects through the marine species monitoring site, 
which serves as a public portal for information regarding all aspects 
of the Navy's monitoring program, including background and guidance 
documents, access to reports, and specific information on current 
monitoring projects.
    Through the adaptive management process (including annual 
meetings), the Navy will coordinate with NMFS and the Commission to 
review and revise, if required, the list of intermediate scientific 
objectives that are used to guide development of individual monitoring 
projects. As described previously in the Monitoring section of this 
document, NMFS and the Commission will also have the opportunity to 
attend annual monitoring program science review meetings and/or 
regional Scientific Advisory Group meetings.
    The Navy will continue to submit annual monitoring reports to NMFS, 
which describe the results of the adaptive management process and 
summarize the Navy's anticipated monitoring projects for the next 
reporting year. NMFS will have a three-month review period to comment 
on the next year's planned projects, ongoing regional projects, and 
proposed new project starts. NMFS' comments will be submitted to the 
Navy prior to the annual adaptive management meeting to facilitate a 
meaningful and productive discussion between NMFS, the Navy, and the 
Commission.

Effects Analysis/Takes

    Comment 10: The Commission recommended that NMFS authorize the 
total numbers of model-estimated Level A harassment and mortality takes 
rather than allowing the Navy to reduce the estimated numbers of Level 
A harassment and mortality takes based on the Navy's proposed post-
model analysis.
    Response 10: NMFS believes that the post-modeling analysis is an 
effective method for quantifying the implementation of mitigation 
measures to reduce impacts on marine mammals, and that the resulting 
exposure estimates are, nevertheless, a conservative estimate of 
impacts on marine mammals.
    See Section 3.4.3.2 (Marine Mammal Avoidance of Sound Exposures) as 
presented in the MITT FEIS/OEIS for the discussion of the science 
regarding the avoidance of sound sources by marine mammals. In 
addition, the Technical Report, Post-Model Quantitative Analysis of 
Animal Avoidance Behavior and Mitigation Effectiveness for the Mariana 
Islands Training and Testing (http://www.mitt-eis.com), goes into 
detail on how the avoidance and mitigation factors were used and 
provides scientific support from peer-reviewed research. The Navy 
analysis does not indicate nor is it expected that marine mammals would 
abandon important habitat on a long-term or even permanent basis. As 
presented in Section 3.4.5.2 (Summary of Observations During Previous 
Navy Activities) of the MITT FEIS/OEIS, the information gathered to 
date including research, monitoring before, during, and after training 
and testing events across the Navy since 2006, has resulted in the 
assessment that it is unlikely there will be impacts on populations of 
marine mammals (such as whales, dolphins and porpoise) having any long-
term consequences as a result of the proposed continuation of training 
and testing in the ocean areas historically used by the Navy including 
the Study Area.
    As part of the post-modeling analysis, the Navy reduced some 
predicted PTS exposures and mortality based on the potential for marine 
mammals to be detected and mitigation implemented. Given this 
potential, not taking into account some possible reduction in Level A 
exposures and mortality would result in a less realistic, 
overestimation of possible Level A and mortality takes, as if there 
were no mitigation measures implemented. The period of time between 
clearing the impact area of any non-participants or marine mammals and 
weapons release is on the order of minutes, making it highly unlikely 
that a marine mammal would enter the mitigation zone.
    The assignment of mitigation effectiveness scores and the 
appropriateness of consideration of sightability using detection 
probability, g(O), when assessing the mitigation in the quantitative 
analysis of acoustic impacts is discussed in the MITI FEIS/OEIS 
(Section 3.4.3.3, Implementing Mitigation to Reduce Sound Exposures). 
Additionally, the activity category, mitigation zone size, and number 
of Lookouts are provided in the proposed rule (FR 79 15388) and MITT 
FEIS/OEIS (Section 5, Tables 5.3-2 and 5.4-1). In addition to the 
information already contained within the MITT FEIS/OEIS, the Post-Model 
Quantitative Analysis of Animal Avoidance Behavior and Mitigation 
Effectiveness for the Mariana Islands Training and Testing Technical 
Report (http://www.mitt-eis.com) describes the process for the post-
modeling analysis in further detail. There is also information on 
visual detection leading to the implementation of mitigation in the 
annual exercise reports provided to NMFS and briefed annually to NMFS 
and the Commission. These annual exercise reports have been made 
available and can be found at http://www.navymarinespeciesmonitoring.us/ in addition to http://www.nmfs.noaa/pr/permits/incidental.
    In summary, NMFS and the Navy believe consideration of marine 
mammal sightability and activity-specific mitigation effectiveness is 
appropriate in the Navy's quantitative analysis in order to provide 
decision makers a reasonable assessment of potential impacts under each 
alternative. A comprehensive discussion of the Navy's quantitative 
analysis of acoustic impacts, including the post-model analysis to 
account for mitigation and avoidance, is presented in Chapter 6 of the 
LOA application.
    Comment 11: The Commission recommended that NMFS require the Navy 
to round its takes, based on those takes in the MITT FEIS/OEIS Criteria 
and Thresholds Technical Report tables, to the nearest whole number or 
zero in all of its take tables and then authorize those numbers of 
takes.
    Response 11: The exposure numbers presented in the MITT FEIS/OEIS 
Criteria and Thresholds Technical Report are raw model output that have 
not been adjusted by post-processing to account for likely marine 
mammal behavior or the effect from implementation of mitigation 
measures. All fractional post-processed exposures for a species across 
all events within

[[Page 46146]]

each category subtotal (Training, Testing, Impulse, and Non-Impulse) 
are summed to provide an annual total predicted number of effects. The 
final exposure numbers presented in the LOA application and the MITT 
FEIS/OEIS incorporate post-processed exposures numbers that have been 
rounded down to the nearest integer so that subtotals correctly sum to 
total annual effects rather than exceed the already overly conservative 
total exposure numbers.
    Comment 12: Senator Vicente (ben) C. Pangelinan (32nd Guam 
Legislature) expressed concerns with the purported lack of data or 
supporting studies in the proposed rule on how anthropogenic sound will 
affect reproduction and survival of marine mammals in the Study Area. 
The Senator cites studies by Claridge (2013) and others (e.g., 
International Whaling Commission, 2005) that suggest stressors 
associated with Navy sonar use and impulse sound may lead to strandings 
and lower reproductive rates in some species. The Senator also points 
out that several authors have established that long-term and intense 
disturbance stimuli can cause population declines in some (terrestrial) 
species.
    Response 12: NMFS fully considers impacts to recruitment and 
survival (population-level effects) when making a negligible impact 
determination and when prescribing the means of effecting the least 
practicable impact on species and stocks. 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. Recent 
studies have been published regarding behavioral responses that are 
relevant to the proposed activities and energy sources: Moore and 
Barlow, 2013; DeRuiter et al., 2013; and Goldbogen et al., 2013, among 
others. 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. In addition, New et al., 2013 and 2014; Houser et al., 2013; 
and Claridge, 2013 were recently published. These and other relevant 
studies are discussed in both the Potential Effects of Specified 
Activities on Marine Mammals section and the Analysis and Negligible 
Impact Determination section of this final rule.
    The Analysis and Negligible Impact Determination section of this 
final rule includes a species or group-specific analysis (see Group and 
Species-Specific Analysis) of potential effects on marine mammal in the 
Study Area, as well as a discussion on long-term consequences (see 
Long-Term Consequences) for individuals or populations resulting from 
Navy training and testing activities in the Study Area. As discussed 
later in this document, populations of beaked whales and other 
odontocetes in the Bahamas, and in other Navy fixed ranges that have 
been operating for tens of years, appear to be stable. Range complexes 
where intensive training and testing have been occurring for decades 
have populations of multiple species with strong site fidelity 
(including highly sensitive resident beaked whales at some locations) 
and increases in the number of some species.
    There is no direct evidence that routine Navy training and testing 
spanning decades has negatively impacted marine mammal populations at 
any Navy range complex. In at least three decades of similar 
activities, only one instance of injury to marine mammals (March 4, 
2011; three long-beaked common dolphin) has been documented as a result 
of training or testing using an impulse source (underwater explosion). 
Years of monitoring of Navy-wide activities (since 2006) have 
documented hundreds of thousands of marine mammals on the range 
complexes and there are only two instances of overt behavioral change 
that have been observed. Years of monitoring of Navy-wide activities on 
the range complexes have documented no demonstrable instances of injury 
to marine mammals as a direct result of non-impulsive acoustic sources.
    Stranding events coincident with Navy MFAS use in which exposure to 
sonar is believed to have been a contributing factor were detailed in 
the Stranding and Mortality section of the proposed rule. However, for 
some of these stranding events, a causal relationship between sonar 
exposure and the stranding could not be clearly established (Cox et 
al., 2006). In other instances, sonar was considered only one of 
several factors that, in their aggregate, may have contributed to the 
stranding event (Freitas, 2004; Cox et al., 2006). NMFS and the Navy 
have identified certain circumstances/factors (including the presence 
of a surface duct, unusual and steep bathymetry, a constricted channel 
with limited egress, intensive use of multiple, active sonar units over 
an extended period of time, and the presence of beaked whales that 
appear to be sensitive to the frequencies produced by these sonars) 
that have been present in some instances where strandings are 
associated with active Navy sonar (e.g., Bahamas, 2000). Based on this, 
NMFS believes that the operation of MFAS in situations where surface 
ducts exist, or in marine environments defined by steep bathymetry and/
or constricted channels may increase the likelihood of producing a 
sound field with the potential to cause cetaceans (especially beaked 
whales) to strand, and therefore, suggests the need for increased 
vigilance while operating MFAS in these areas, especially when beaked 
whales (or potentially other deep divers) are likely present. In 
addition, the Navy has developed specific planning and monitoring 
measures to use when that suite of factors is present. These 
circumstances/factors do not exist in their aggregate in the MITT Study 
Area.
    Because of the association between tactical MFA sonar use and a 
small number of marine mammal strandings, the Navy and NMFS have been 
considering and addressing the potential for strandings in association 
with Navy activities for years. In addition to a suite of mitigation 
intended to more broadly minimize impacts to marine mammals, the Navy 
and NMFS have a detailed Stranding Response Plan that outlines 
reporting, communication, and response protocols intended both to 
minimize the impacts of, and enhance the analysis of, any potential 
stranding in areas where the Navy operates.
    Based on the best available science NMFS concludes that exposures 
to marine mammal species and stocks due to MITT activities would result 
in only short-term effects to most individuals exposed and are not 
expected to affect annual rates of recruitment or survival (population-
level impacts having any long-term consequences). Results of the Navy's 
acoustic analysis and NMFS' analysis, as well as the relevant studies 
supporting this conclusion, are referenced and summarized in the 
Analysis and Negligible Impact Determination section of this final 
rule.

Criteria and Thresholds

    Comment 13: The Commission recommended that NMFS require the Navy 
to (1) use 157 rather than 152 dB re 1 [mu]Pa\2\-sec as the temporary 
threshold shift (TTS) threshold for high-frequency cetaceans exposed to 
acoustic sources, (2) use 169 rather than 172 dB re 1 [mu]Pa\2\-sec as 
the TTS thresholds for mid- and low-frequency cetaceans exposed to 
explosive sources, (3) use 145 rather than 146 dB re 1 [mu]Pa\2\-sec as 
the TTS threshold for high-frequency cetaceans for explosive sources, 
and (4)(a) based on these changes to the TTS thresholds, adjust the 
permanent threshold shift (PTS) thresholds for high-frequency

[[Page 46147]]

cetaceans exposed to acoustic sources by increasing the amended TTS 
threshold by 20 dB, and for low-, mid-, and high-frequency cetaceans 
exposed to explosive sources, by increasing the amended TTS thresholds 
by 15 dB and (b) adjust the behavioral thresholds for low-, mid-, and 
high-frequency cetaceans exposed to explosive sources by decreasing the 
amended TTS thresholds by 5 dB.
    Response 13: NMFS does not concur with the Commissions' 
recommendations for similar reasons to those provided in prior 
responses to Comission comments on the HSTT and AFTT proposed 
rulemakings. The values derived for impulsive and non-impulsive TTS are 
based on data from peer-reviewed scientific studies. The development of 
these thresholds and criteria is detailed in the Criteria and 
Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis 
Technical Report (Finneran and Jenkins, 2012) that is referenced in the 
MITT FEIS/OEIS (see Section 3.4.3.1.4 [Thresholds and Criteria for 
Predicting Acoustic and Explosive Impacts on marine mammals]) and 
available at http://www.mitt-eis.com.
    As presented in Finneran and Jenkins (2012) the thresholds 
incorporate new findings since the publication of Southall et al. 
(2007) and the evolution of scientific understanding since that time. 
Note that Dr. Finneran was one of the authors for Southall et al. 
(2007) and so is completely familiar with the older conclusions 
presented in the 2007 publication and, therefore, was able to integrate 
knowledge into development of the refined approach presented in 
Finneran and Jenkins (2012) based on evolving science since 2007.
    Briefly, the original experimental data is weighted using the 
prescribed weighting function to determine the numerical threshold 
value. The Commission did not consider the appropriate weighting 
schemes when comparing thresholds presented in Southall et al. (2007) 
and those presented in Finneran and Jenkins (2012). TTS thresholds 
presented in Finneran and Jenkins (2012) are appropriate when the 
applicable weighting function (Type II) is applied to the original TTS 
data; TTS thresholds in Southall et al. (2007) were based on M-
weighting.
    For example, while it is true that there is an unweighted 12-dB 
difference for onset-TTS between beluga watergun (Finneran et al., 
2002) and tonal exposures (Schlundt et al., 2000), the difference after 
weighting with the Type II MF-cet weighting function (from Finneran and 
Jenkins, 2012), is 6-dB. The Commission has confused (a) the 6 dB 
difference in PTS and TTS thresholds based on peak pressure described 
in Southall et al. 2007 with (b) the difference between impulsive and 
non-impulsive thresholds in Finneran and Jenkins (2012), which is 
coincidentally 6 dB.
    The same offset between impulsive and non-impulsive temporary 
threshold shift, for the only species where both types of sound were 
tested (beluga), was used to convert the Kastak et al. (2005) data 
(which used non-impulsive tones) to an impulsive threshold. This method 
is explained in Finneran and Jenkins (2012) and Southall et al. (2007).
    The thresholds and criteria used in the MITT analysis have already 
incorporated the correct balance of conservative assumptions that tend 
towards overestimation in the face of uncertainty. Additional details 
regarding the process are provided in Section 3.4.3.1.5 (Quantitative 
Analysis) of the MITT FEIS/OEIS. In addition, the summary of the 
thresholds used in the analysis are presented in Section 3.4.3.1.4 
(Thresholds and Criteria for Predicting Acoustic and Explosive Impacts 
on Marine Mammals) of the MITT FEIS/OEIS. NMFS was included in the 
development of the current thresholds. The thresholds used in the 
current analysis remain the best available estimate of the number and 
type of take that may result from the Navy's use of acoustic sources in 
the MITT Study Area, although NMFS and the Navy will continue to revise 
those thresholds based on emergent research.
    Comment 14: The Commission recommended that NMFS require the Navy 
to (1) describe what it used as the upper limit of behavioral response 
function for low-frequency cetaceans (BRF1) and the upper 
limits of BRF2 for both mid- and high-frequency cetaceans, 
including if it assumed a 1-sec ping for all sources and (2) if the 
upper limits of the BRFs were based on weighted thresholds, use the 
unweighted or M-weighted thresholds of 195 dB re 1 [mu]Pa\2\-sec for 
low- and mid-frequency cetaceans and 176 dB re 1 [mu]Pa\2\-sec for 
high-frequency cetaceans to revise its behavior take estimates for all 
marine mammals exposed to acoustic sources.
    Response 14: The behavioral response functions (BRFs) used to 
define criteria for assessing behavioral responses to underwater sound 
sources are discussed in Section 3.4.3.1.4 (Thresholds and Criteria for 
Predicting Acoustic and Explosive Impacts on Marine Mammals) of the 
FEIS/OEIS and in the Technical Report, Criteria and Thresholds for U.S. 
Navy Acoustic and Explosive Effects Analysis (Finneran and Jenkins, 
2012). The BRFs have been used by the Navy to assess behavioral 
reactions in marine mammals for several years and are described in 
greater detail in the Atlantic Fleet Active Sonar Training EIS/OEIS 
(see Section 4.4.5.3.2 Development of the Risk Function), as well as in 
the Southern California Range Complex EIS/OEIS and the Hawaii Range 
Complex EIS/OEIS.
    Harassment under the BRF and harassment under the TTS criteria are 
both considered Level B takes under MMPA, and NMFS has determined that 
animals whose exposure both exceeds TTS threshold and results in 
behavioral response under the BRF should not be double counted or 
counted as taken twice by the same acoustic exposure. Although 
behavioral responses (non-TTS) and TTS are both considered as Level B 
under the MMPA for military readiness, they are two separate criteria 
based on different metrics and different frequency weighting systems. 
Sound exposure level (SEL) is the most appropriate metric to predict 
TTS, because it accounts for signal duration. Sound pressure level 
(SPL) is independent of signal duration and is the metric that best 
correlates with potential behavioral response. Furthermore, to predict 
TTS, SEL is weighted with a Type II function for cetaceans, whereas to 
predict a behavioral response, SPL is weighted with a Type I function. 
Mathematically, SEL (for TTS) and SPL (for behavior) are not on the 
same linear scale, and their relationship to one another changes based 
on the frequency and duration of the sounds being analyzed.
    Based on the model-estimated exposure results, an animat (virtual 
representation of an animal) exposed to sound that exceeds both the TTS 
(SEL) threshold and Behavioral (SPL) threshold is reported as a TTS 
(higher level) effect. It is important to note that TTS is a step 
function, so 100 percent of animals predicted to equal or surpass the 
TTS threshold would be counted as TTS effects. Behavioral effects are 
estimated as the percentage of animals (i.e. between 0 and 100 percent) 
that may be affected based on the highest received SPL on a BRF.

Vessel Strikes

    Comment 15: The Commission recommended that NMFS require the Navy 
to use its spatially and temporally dynamic simulation models rather 
than simple probability calculations to estimate strike probabilities 
for specific activities (i.e., movement of vessels, torpedoes, unmanned 
underwater vehicles and use of expended

[[Page 46148]]

munitions, ordnance, and other devices).
    Response 15: The Navy considered using a dynamic simulation model 
to estimate strike probability. However, the Navy determined, and NMFS 
concurs, that the use of historical data was a more appropriate way to 
analyze the potential for strike. The Navy's strike probability 
analysis in the MITT FEIS/OEIS is based upon actual data collected from 
historical use of vessels, in-water devices, and military expended 
materials, and the likelihood that these items may have the potential 
to strike an animal. This data accounts for real world variables over 
the course of many years, and any model would be expected to be less 
accurate than the use of actual data. There is no available science 
regarding the necessary functional parameters for a complex dynamic 
whale strike simulation model; there are large unknowns regarding the 
data that would be necessary such as the density, age classes, and 
behavior of large whales in the MITT Study Area; and there are no means 
to validate the output of a model given there is no empirical data (not 
strikes) to ``seed the dynamic simulation.'' Therefore, use of 
historical data from identical activities elsewhere and additional use 
of a probability analysis remain a more reasonable analytical approach.
    The Commission's disagreement over the method the Navy has used to 
estimate strike probability is noted. Any increase in vessel movement, 
as discussed in Section 3.4.4.4.1 (Impacts from Vessels) of the MITT 
FEIS/OEIS, over the No Action is still well below areas such as the 
Southern California Range Complex (SOCAL) where the density of large 
whales and the number of Navy Activities is much higher than any of the 
MITT alternatives and yet strikes to large whales are still relatively 
rare in SOCAL. Additionally, while the number of training and testing 
activities is likely to increase, it is not expected to result in an 
appreciable increase in vessel use or transits since multiple 
activities usually occur from the same vessel. The Navy is not 
proposing substantive changes in the locations where vessels have been 
used over the last decade.
    There has never been a vessel strike to a whale during any active 
training or testing activities in the Study Area. A detailed analysis 
of strike data is also contained in Chapter 6 (Section 6.3.4, Estimated 
Take of Large Whales by Navy Vessel Strike) of the LOA application. The 
Navy does not anticipate vessel strikes to marine mammals during 
training or testing activities within the Study Area, nor were takes by 
injury or mortality resulting from vessel strike predicted in the 
Navy's analysis. Therefore, NMFS is not authorizing mysticete takes (by 
injury or mortality) from vessel strikes during the 5-year period of 
the MITT regulations.

General Opposition

    Comment 16: One commenter expressed general opposition to Navy 
activities and NMFS' issuance of an MMPA authorization.
    Response 16: NMFS appreciates the commenter's concern for the 
marine environment. However, the MMPA directs NMFS to issue an 
incidental take authorization if certain findings can be made. NMFS has 
determined that the Navy's training and testing activities will have a 
negligible impact on the affected species or stocks and, therefore, we 
plan to issue the requested MMPA authorization.

Other

    Comment 17: One commenter asked about the effects of Navy 
activities on marine habitat and other resources not addressed in the 
proposed rule.
    Response 17: The MITT FEIS/OEIS addresses all potential impacts to 
the human environment, and is available online at http://www.mitt-eis.com. The MITT DEIS/OEIS was made available to the public on 
September 13, 2013 and was referenced in the proposed rule (79 FR 
15388, March 19, 2014).
    Comment 18: One commenter requested additional details or 
elaboration regarding specific Navy training and testing activities 
(e.g., vessel type and speed, inwater detonations, Pierside Location 
maintenance, etc.).
    Response 18: Detailed information about each proposed activity 
(stressor, training or testing event, description, sound source, 
duration, and gepgraphic location) can be found in the MITT FEIS/OEIS.
    Comment 19: One commenter had several questions regarding 
information (e.g., species presence, distribution, stock abundance, 
ESA/MMPA status) presented in Table 6 (Marine Mammals with Possible or 
Confirmed Presence within the Study Area) and the Description of Marine 
Mammals in the Area of the Specified Activity section of the proposed 
rule.
    Response 19: As stated in the proposed rule, information on the 
status, occurrence and distribution, abundance, derivation of density 
estimates, and vocalizations of marine mammal species in the Study Area 
may be viewed in Chapters 3 and 4 of the LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/). This information was 
compiled by the Navy from peer-reviewed literature, NMFS annual stock 
assessment reports (SARs) for marine mammals (http://www.nmfs.noaa.gov/pr/species/mammals; Carretta et al., 2014; Allen and Angliss, 2014), 
and marine mammal surveys using acoustic and visual observations from 
aircraft and ships. Further information on the general biology and 
ecology of marine mammals is included in the MITT FEIS/OEIS (http://www.mitt-eis.com.).
    Comment 20: One commenter questioned NMFS' proposed authorization 
of take through issuance of a single 5-year LOA (multi-year LOA) rather 
than issuance of annual LOAs.
    Response 20: The ability to issue a multi-year LOA reduces 
administrative burdens on both NMFS and the Navy. In addition, a multi-
year LOA would avoid situations where the last minute issuance of LOAs 
necessitates the commitment of extensive resources by the Navy for 
contingency planning.
    The regulations still: (1) Require the Navy to submit annual 
monitoring and exercise reports; (2) require that NMFS and the Navy 
hold annual monitoring and adaptive management meetings that ensure 
NMFS is able to evaluate the Navy's compliance and marine mammal 
impacts with the same attention and frequency; and (3) allow for a LOA 
to be changed at any time, as appropriate, to incorporate any needed 
mitigation or monitoring measures developed through adaptive 
management, based on the availability of new information regarding 
military readiness activities or the marine mammals affected. If, 
through adaptive management, proposed modifications to the mitigation, 
monitoring, or reporting measures are substantial, NMFS would publish a 
notice of proposed LOA in the Federal Register and solicit public 
comment.

Estimated Take

    In the Estimated Take section of the proposed rule, NMFS described 
the potential effects to marine mammals from active sonar and 
underwater detonations in relation to the MMPA regulatory definitions 
of Level A and Level B harassment (79 FR 15388, pages 15426-15430). 
That information has not changed and is not repeated here. It is 
important to note that, as Level B Harassment is interpreted here and 
quantified by the behavioral thresholds described below, the fact that 
a single behavioral pattern (of unspecified duration) is abandoned or 
significantly altered and classified as a Level B take does not mean, 
necessarily, that the

[[Page 46149]]

fitness of the harassed individual is affected either at all or 
significantly, or that, for example, a preferred habitat area is 
abandoned. Further analysis of context and duration of likely exposures 
and effects is necessary to determine the impacts of the estimated 
effects on individuals and how those may translate to population-level 
impacts, and is included in the Analysis and Negligible Impact 
Determination.
    Tables 8 and 9 provide a summary of non-impulsive and impulsive 
thresholds to TTS and PTS for marine mammals. A detailed explanation of 
how these thresholds were derived is provided in the MITT FEIS/OEIS 
Criteria and Thresholds Technical Report (http://www.mitt-eis.com) and 
summarized in Chapter 6 of the Navy's LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/).

                           Table 8--Onset TTS and PTS Thresholds for Non-Impulse Sound
----------------------------------------------------------------------------------------------------------------
                Group                          Species                 Onset TTS                Onset PTS
----------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans..............  All mysticetes.........  178 dB re 1[mu]Pa2-      198 dB re 1[mu]Pa2-
                                                                 sec(LFII).               sec(LFII).
Mid-Frequency Cetaceans..............  Most delphinids, beaked  178 dB re 1[mu]Pa2-      198 dB re 1[mu]Pa2-
                                        whales, medium and       sec(MFII).               sec(MFII).
                                        large toothed whales.
High-Frequency Cetaceans.............  Porpoises, Kogia spp...  152 dB re 1[mu]Pa2-      172 dB re 1[mu]Pa2-
                                                                 sec(HFII).               secSEL (HFII).
----------------------------------------------------------------------------------------------------------------
LFII, MFII, HFII: New compound Type II weighting functions.


                                    Table 9--Impulsive Sound Explosive Thresholds for Predicting Injury and Mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Slight Injury
               Group                       Species        -----------------------------------------------------------------------        Mortality
                                                                    PTS                  GI Tract                  Lung
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency Cetaceans...........  All mysticetes.......  187 dB SEL (LFII) or
                                                            230 dB Peak SPL.
Mid-frequency Cetaceans...........  Most delphinids,       187 dB SEL (MFII) or   237 dB SPL............  Equation 1............  Equation 2.
                                     medium and large       230 dB Peak SPL.
                                     toothed whales.
High-frequency Cetaceans..........  Porpoises and Kogia    161 dB SEL (HFII) or
                                     spp.                   201 dB Peak SPL.
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                                            [GRAPHIC] [TIFF OMITTED] TR03AU15.012
                                                            
Where:

M = mass of the animals in kg
DRm = depth of the receiver (animal) in meters
[GRAPHIC] [TIFF OMITTED] TR03AU15.000

Where:

R = Risk (0-1.0)
L = Received level (dB re: 1 [mu]Pa)
B = Basement received level = 120 dB re: 1 [mu]Pa
K = Received level increment above B where 50-percent risk = 45 dB 
re: 1 [mu]Pa
A = Risk transition sharpness parameter = 10 (odontocetes) or 8 
(mysticetes)

Take Request

    The MITT FEIS/OEIS considered all training and testing activities 
proposed to occur in the Study Area that have the potential to result 
in the MMPA defined take of marine mammals. The potential stressors 
associated with these activities included the following:
     Acoustic (sonar and other active acoustic sources, 
explosives, weapons firing, launch and impact noise, vessel noise, 
aircraft noise);
     Energy (electromagnetic devices);
     Physical disturbance or strikes (vessels, in-water 
devices, military expended materials, seafloor devices);
     Entanglement (fiber optic cables, guidance wires, 
parachutes);
     Ingestion (munitions, military expended materials other 
than munitions);
     Indirect stressors (impacts to habitat [sediment and water 
quality, air quality] or prey availability).
    NMFS has determined that two stressors could potentially result in 
the incidental taking of marine mammals from training and testing 
activities within the Study Area: (1) Non-impulse acoustic stressors 
(sonar and other active acoustic sources) and (2) impulse acoustic 
stressors (explosives). Non-impulse and impulse stressors have the 
potential to result in incidental takes of marine mammals by Level A 
(injury) or Level B (behavioral) harassment. NMFS also considered the 
potential for vessel strikes to impact marine mammals, and that 
assessment is presented below. Lethal takes of large whales and beaked 
whales, while not anticipated or predicted in the Navy's acoustic 
analysis, were originally conservatively requested by the Navy for MITT 
training

[[Page 46150]]

and testing activities over the 5-year period of NMFS' final 
authorization. That request was included in NMFS' proposed rule (79 FR 
15388, Take Request); however, NMFS has since made the decision not to 
authorize any lethal takes for MITT activities for reasons discussed 
below.
    Training and Testing Activities--Based on the Navy's modeling and 
post-model analysis (i.e., the acoustic analysis) (described in detail 
in Chapter 6 of their LOA application), Table 10 summarizes the 
authorized takes for training and testing activities for an annual 
maximum year (a notional 12-month period when all annual and non-annual 
events could occur) and the summation over a 5-year period (annual 
events occurring five times and non-annual events occurring three 
times). Table 11 summarizes the authorized takes for training and 
testing activities by species from the modeling estimates.
    Predicted effects on marine mammals result from exposures to sonar 
and other active acoustic sources and explosions during annual training 
and testing activities. The acoustic analysis predicts the majority of 
marine mammal species in the Study Area would not be exposed to 
explosive (impulse) sources associated with training and testing 
activities that would exceed the current impact thresholds.
    No beaked whales are predicted in the acoustic analysis to be 
exposed to sound levels associated with PTS, other injury, or 
mortality. The Navy had originally conservatively requested 
authorization for beaked whale mortality (no more than 10 mortalities 
over 5 years) that might potentially result from exposure to active 
sonar, based on the few instances where sonar has been associated with 
strandings in other areas. That request was included in NMFS' proposed 
rule (79 FR 15388, Take Request). However, after decades of the Navy 
conducting similar activities in the MITT Study Area without incident, 
neither the Navy nor NMFS expect stranding, injury, or mortality of 
beaked whales to occur as a result of Navy activities, and therefore, 
following consultation with the Navy, NMFS is not authorizing any Level 
A (injury or mortality) takes for beaked whales. In addition to a suite 
of mitigation intended to more broadly minimize impacts to marine 
mammals, the Navy and NMFS have a detailed Stranding Response Plan 
(described in the Mitigation section of this final rule and available 
at http://www.nmfs.noaa.gov/pr/permits/incidental/) that outlines 
reporting, communication, and response protocols intended both to 
minimize the impacts of, and enhance the analysis of, any potential 
stranding in areas where the Navy operates.
    Vessel Strike--There has never been a vessel strike to a marine 
mammal during any active training or testing activities in the Study 
Area. A detailed analysis of strike data is contained in Chapter 6 
(Section 6.3.4, Estimated Take of Large Whales by Navy Vessel Strike) 
of the LOA application. There have been Navy strikes of large whales in 
areas outside the Study Area, such as Hawaii and Southern California. 
However, these areas differ significantly from the Study Area given 
that both Hawaii and Southern California have a much higher number of 
Navy vessel activities and much higher densities of large whales. The 
Navy does not anticipate vessel strikes to marine mammals during 
training or testing activities within the Study Area, nor were takes by 
injury or mortality resulting from vessel strike predicted in the 
Navy's analysis. Vessel strike to marine mammals is not associated with 
any specific training or testing activity but rather a limited, 
sporadic, and accidental result of Navy vessel movement. In order to 
account for the accidental nature of vessel strikes to large whales in 
general, and the potential risk from any vessel movement within the 
MITT Study Area, the Navy had originally conservatively requested 
authorization for large whale mortalities (no more than 5 mortalities 
over 5 years) that might potentially result from vessel strike during 
MITT training and testing activities over the 5-year period of NMFS' 
final authorization. That request was included in NMFS' proposed rule 
(79 FR 15388, Take Request). However, after further consideration of 
the Navy's ship strike analysis, the unlikelihood of a ship strike to 
occur and the fact that there has never been a ship strike to marine 
mammals in the Study Area, and following consultation with the Navy, 
NMFS is not authorizing takes (by injury or mortality) from vessel 
strikes during the 5-year period of the MITT regulations. The Navy has 
proposed measures (see Mitigation) to mitigate potential impacts to 
marine mammals from vessel strikes during training and testing 
activities in the Study Area.

           Table 10--Summary of Authorized Annual and 5-Year Takes for Training and Testing Activities
----------------------------------------------------------------------------------------------------------------
                                                                        Training and testing activities
          MMPA Category                      Source          ---------------------------------------------------
                                                               Annual authorization 1    5-Year authorization 2
----------------------------------------------------------------------------------------------------------------
Level A..........................  Impulse and Non-Impulse..  56-Species specific data  280-Species specific
                                                               shown in Table 11.        data shown in Table 11
Level B..........................  Impulse and Non-Impulse..  81,906-Species specific   409,530-Species specific
                                                               data shown in Table 11.   data shown in Table 11
----------------------------------------------------------------------------------------------------------------
\1\ These numbers constitute the total for an annual maximum year (a notional 12-month period when all annual
  and non-annual events could occur).
\2\ These numbers constitute the summation over a 5-year period with annual events occurring five times and non-
  annual events occurring three times.


  Table 11--Authorized Species-Specific Takes From Modeling and Post-Model Estimates of Impulsive and Non-Impulsive Source Effects for All Training And
                                                                   Testing Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                            Annually 1                               Total over 5-year rule 2
                         Species                         -----------------------------------------------------------------------------------------------
                                                              Level B         Level A        Mortality        Level B         Level A        Mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale..............................................              28               0               0             140               0               0
Fin whale...............................................              28               0               0             140               0               0
Humpback whale..........................................             860               0               0           4,300               0               0
Sei whale...............................................             319               0               0           1,595               0               0
Sperm whale.............................................             506               0               0           2,530               0               0

[[Page 46151]]

 
Bryde's whale...........................................             398               0               0           1,990               0               0
Minke whale.............................................             101               0               0             505               0               0
Omura's whale...........................................             103               0               0             515               0               0
Pygmy sperm whale.......................................           5,579              15               0          27,895              75               0
Dwarf sperm whale.......................................          14,217              41               0          71,085             205               0
Killer whale............................................              84               0               0             420               0               0
False killer whale......................................             555               0               0           2,775               0               0
Pygmy killer whale......................................             105               0               0             525               0               0
Short-finned pilot whale................................           1,815               0               0           9,075               0               0
Melon-headed whale......................................           2,085               0               0          10,425               0               0
Bottlenose dolphin......................................             741               0               0           3,705               0               0
Pantropical spotted dolphin.............................          12,811               0               0          64,055               0               0
Striped dolphin.........................................           3,298               0               0          16,490               0               0
Spinner dolphin.........................................             589               0               0           2,945               0               0
Rough toothed dolphin...................................           1,819               0               0           9,095               0               0
Fraser's dolphin........................................           2,572               0               0          12,860               0               0
Risso's dolphin.........................................             505               0               0           2,525               0               0
Cuvier's beaked whale...................................          22,541               0               0         112,705               0               0
Blainville's beaked whale...............................           4,426               0               0          22,130               0               0
Longman's beaked whale..................................           1,924               0               0           9,620               0               0
Ginkgo-toothed beaked whale.............................           3,897               0               0          19,485               0               0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ These numbers constitute the total for an annual maximum year (a notional 12-month period when all annual and non-annual events could occur).
\2\ These numbers constitute the summation over a 5-year period with annual events occurring five times and non-annual events occurring three times.

Marine Mammal Habitat

    The Navy's proposed training and testing activities could 
potentially affect marine mammal habitat through the introduction of 
sound into the water column, impacts to the prey species of marine 
mammals, bottom disturbance, or changes in water quality. Each of these 
components was considered in Chapter 3 of the MITT FEIS/OEIS. Based on 
the information in the Marine Mammal Habitat section of the proposed 
rule (79 FR 15388, March 19, 2014; pages 15412-15414) and the 
supporting information included in the MITT FEIS/OEIS, NMFS has 
determined that training and testing activities would not have adverse 
or long-term impacts on marine mammal habitat. In summary, expected 
effects to marine mammal habitat will include elevated levels of 
anthropogenic sound in the water column; short-term physical alteration 
of the water column or bottom topography; brief disturbances to marine 
invertebrates; localized and infrequent disturbance to fish; a limited 
number of fish mortalities; and temporary marine mammal avoidance.

Analysis and Negligible Impact Determination

    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 takes, alone, is not 
enough information on which to base an impact determination, as the 
severity of harassment may vary greatly depending on the context and 
duration of the behavioral response, many of which would not be 
expected to have deleterious impacts on the fitness of any individuals. 
In determining whether the expected takes will have a negligible 
impact, in addition to considering estimates of the number of marine 
mammals that might be ``taken'', 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 (e.g., 
severity) of estimated Level A harassment takes, the number of 
estimated mortalities, and the status of the species.
    The Navy's specified activities have been described based on best 
estimates of the maximum amount of sonar and other acoustic source use 
or detonations that the Navy would conduct. There may be some 
flexibility in that the exact number of hours, items, or detonations 
may vary from year to year, but take totals are not authorized to 
exceed the 5-year totals indicated in Table 11. We base our analysis 
and NID on the maximum number of takes authorized.
    To avoid repetition, we provide some general analysis immediately 
below that applies to all the species listed in Table 11, given that 
some of the anticipated effects (or lack thereof) of the Navy's 
training and testing activities on marine mammals are expected to be 
relatively similar in nature. However, below that, we break our 
analysis into species, or groups of species where relevant similarities 
exist, to provide more specific information related to the anticipated 
effects on individuals or where there is information about the status 
or structure of any species that would lead to a differing assessment 
of the effects on the population.
    The Navy's take request is based on its model and post-model 
analysis. In the discussions below, the ``acoustic analysis'' refers to 
the Navy's modeling results and post-model analysis. The model 
calculates sound energy propagation from sonars, other active acoustic 
sources, and explosives during naval activities; the sound or impulse 
received by animat dosimeters representing marine mammals distributed 
in the area around the modeled activity; and whether the sound or 
impulse received by a marine mammal exceeds the thresholds for effects. 
The model estimates are then further analyzed to consider animal

[[Page 46152]]

avoidance and implementation of highly effective mitigation measures to 
prevent Level A harassment, resulting in final estimates of effects due 
to Navy training and testing. NMFS provided input to the Navy on this 
process and the Navy's qualitative analysis is described in detail in 
Chapter 6 of their LOA application (http://www.nmfs.noaa.gov/pr/permits/incidental/).
    Generally speaking, and especially with other factors being equal, 
the Navy and NMFS anticipate more severe effects from takes resulting 
from exposure to higher received levels (though this is in no way a 
strictly linear relationship throughout species, individuals, or 
circumstances) and less severe effects from takes resulting from 
exposure to lower received levels. It is important to note that the 
requested and authorized number of takes does not equate to the number 
of individual animals the Navy expects to harass (which is lower), but 
rather to the instances of take (i.e., exposures above the Level B or 
Level A harassment threshold) that would occur. Additionally, these 
instances may represent either a very brief exposure (seconds) or, in 
some cases, longer durations of exposure within a day. Depending on the 
location, duration, and frequency of activities, along with the 
distribution and movement of marine mammals, individual animals may be 
exposed to impulse or non-impulse sounds at or above the harassment 
thresholds on multiple days. However, the Navy is currently unable to 
estimate the number of individuals that may be taken during training 
and testing activities. The model results estimate the total number of 
takes that may occur to a smaller number of individuals. While the 
model shows that an increased number of exposures may take place due to 
an increase in events/activities and ordnance, the types and severity 
of individual responses to training and testing activities are not 
expected to change.

Behavioral Harassment

    As discussed previously in the proposed rule, marine mammals can 
respond to MFAS/HFAS in many different ways, a subset of which 
qualifies as harassment (see Behavioral Harassment section of proposed 
rule). One thing that the Level B harassment take estimates do not take 
into account is the fact that most marine mammals will likely avoid 
strong sound sources to one extent or another. Although an animal that 
avoids the sound source will likely still be taken in some instances 
(such as if the avoidance results in a missed opportunity to feed, 
interruption of reproductive behaviors, etc.), in other cases avoidance 
may result in fewer instances of take than were estimated or in the 
takes resulting from exposure to a lower received level than was 
estimated, which could result in a less severe response. For MFAS/HFAS, 
the Navy provided information (Table 12) estimating the percentage of 
behavioral harassment that would occur within the 6-dB bins (without 
considering mitigation or avoidance). As mentioned above, an animal's 
exposure to a higher received level is more likely to result in a 
behavioral response that is more likely to adversely affect the health 
of the animal. As illustrated below, the majority (about 80 percent, at 
least for hull-mounted sonar, which is responsible for most of the 
sonar takes) of calculated takes from MFAS result from exposures 
between 150 dB and 162 dB. Less than one percent of the takes are 
expected to result from exposures above 174 dB.
    Specifically, given a range of behavioral responses that may be 
classified as Level B harassment, to the degree that higher received 
levels are expected to result in more severe behavioral responses, only 
a small percentage of the anticipated Level B harassment from Navy 
activities might necessarily be expected to potentially result in more 
severe responses, especially when the distance from the source at which 
the levels below are received is considered (see Table 12). Marine 
mammals are able to discern the distance of a given sound source, and 
given other equal factors (including received level), they have been 
reported to respond more to sounds that are closer (DeRuiter et al., 
2013). Further, the estimated number of responses do not reflect either 
the duration or context of those anticipated responses, some of which 
will be of very short duration, and other factors should be considered 
when predicting how the estimated takes may affect individual fitness.

                                                      Table 12--Non-Impulsive Ranges in 6-db Bins and Percentage of Behavioral Harassments
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Sonar bin MF1 (e.g., SQS-53;    Sonar bin MF4 (e.g., AQS-22;    Sonar bin MF5 (e.g., SSQ-62;    Sonar bin HF4 (e.g., SQQ-32;
                                                                      ASW hull mounted sonar)           ASW dipping sonar)                 ASW sonobuoy)                    MIW sonar)
                                                                 -------------------------------------------------------------------------------------------------------------------------------
                                                                                      Percentage                      Percentage                      Percentage                      Percentage
                                                                                          of                              of                              of                              of
                         Received level                           Distance at which   behavioral  Distance at which   behavioral  Distance at which   behavioral  Distance at which   behavioral
                                                                     levels occur    harassments     levels occur    harassments     levels occur    harassments     levels occur    harassments
                                                                   within radius of   occurring    within radius of   occurring    within radius of   occurring    within radius of   occurring
                                                                      source (m)       at given       source (m)       at given       source (m)       at given       source (m)       at given
                                                                                        levels                          levels                          levels                          levels
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Low Frequency Cetaceans
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
120 <=SPL <126..................................................    183,000-133,000           <1      71,000-65,000           <1      18,000-13,000           <1        2,300-1,700           <1
126 <=SPL <132..................................................    133,000-126,000           <1      65,000-60,000           <1       13,000-7,600           <1        1,700-1,200           <1
132 <=SPL <138..................................................     126,000-73,000           <3       60,000-8,200           42        7,600-2,800           12          1,200-750           <1
138 <=SPL <144..................................................      73,000-67,000           <1        8,200-3,500           10          2,800-900           26            750-500            5
144 <=SPL <150..................................................      67,000-61,000            3        3,500-1,800           12            900-500           15            500-300           17
150 <=SPL <156..................................................      61,000-17,000           68          1,800-950           15            500-250           21            300-150           34
156 <=SPL <162..................................................      17,000-10,300           12            950-450           13            250-100           20            150-100           20
162 <=SPL <168..................................................       10,200 5,600            9            450-200            6            100-<50            6            100-<50           24
168 <=SPL <174..................................................        5,600-1,600            6            200-100            2                <50           <1                <50           <1
174 <=SPL <180..................................................          1,600-800           <1            100-<50           <1                <50           <1                <50           <1
180 <=SPL <186..................................................            800-400           <1                <50           <1                <50           <1                <50           <1
186 <=SPL <192..................................................            400-200           <1                <50           <1                <50           <1                <50           <1
192 <= SPL <198.................................................            200-100           <1                <50           <1                <50           <1                <50           <1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Mid-Frequency Cetaceans
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
120 <= SPL <126.................................................    184,000-133,000           <1      72,000-66,000           <1      19,000-15,000           <1        3,600-2,800           <1
126 <= SPL <132.................................................    133,000-126,000           <1      66,000-60,000           <1       15,000-8,500           <1        2,800-2,100           <1
132 <= SPL <138.................................................     126,000-73,000           <1       60,000-8,300           41        8,500-3,300            3        2,100-1,500           <1
138 <= SPL <144.................................................      73,000-67,000           <1        8,300-3,600           10        3,300-1,000           12        1,500-1,000            3
144 <= SPL <150.................................................      67,000-61,000            3        3,600-1,900           12          1,000-500           10           1,00-700           10

[[Page 46153]]

 
150 <= SPL <156.................................................      61,000-18,000           68          1,900-950           15            500-300           22            700-450           21
156 <= SPL <162.................................................      18,000-10,300           13            950-480           12            300-150           27            450-250           32
162 <= SPL <168.................................................       10,300-5,700            9            480-200            7            150-<50           25            250-150           19
168 <= SPL <174.................................................        5,700-1,700            6            200-100            2                <50           <1            150-100            9
174 <= SPL <180.................................................          1,700-900           <1            100-<50           <1                <50           <1            100-<50            6
180 <= SPL <186.................................................            900-400           <1                <50           <1                <50           <1                <50           <1
186 <= SPL <192.................................................            400-200           <1                <50           <1                <50           <1                <50           <1
192 <= SPL <198.................................................            200-100           <1                <50           <1                <50           <1                <50           <1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

    Although the Navy has been monitoring the effects of MFAS/HFAS on 
marine mammals since 2006, and research on the effects of MFAS is 
advancing, our understanding of exactly how marine mammals in the Study 
Area will respond to MFAS/HFAS is still growing. The Navy has submitted 
reports from more than 60 major exercises across Navy range complexes 
that indicate no behavioral disturbance was observed. One cannot 
conclude from these results that marine mammals were not harassed from 
MFAS/HFAS, as a portion of animals within the area of concern were not 
seen (especially those more cryptic, deep-diving species, such as 
beaked whales or Kogia spp.), the full series of behaviors that would 
more accurately show an important change is not typically seen (i.e., 
only the surface behaviors are observed), and some of the non-biologist 
watchstanders might not be well-qualified to characterize behaviors. 
However, one can say that the animals that were observed did not 
respond in any of the obviously more severe ways, such as panic, 
aggression, or anti-predator response.

Diel Cycle

    As noted previously, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing on a diel cycle (24-hour 
cycle). Behavioral reactions to noise exposure (when taking place in a 
biologically important context, 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). Consequently, a behavioral 
response lasting less than one day and not recurring on subsequent days 
is not considered severe unless it could directly affect reproduction 
or survival (Southall et al., 2007). Note that there is a difference 
between multiple-day substantive behavioral reactions and multiple-day 
anthropogenic activities. For example, just because at-sea exercises 
last for multiple days does not necessarily mean that individual 
animals are either exposed to those exercises for multiple days or, 
further, exposed in a manner resulting in a sustained multiple day 
substantive behavioral response. Large multi-day Navy exercises 
typically include assets that travel at high speeds (typically 10-15 
knots, or higher) and likely cover large areas that are relatively far 
from shore, in addition to the fact that marine mammals are moving as 
well, which would make it unlikely that the same animal could remain in 
the immediate vicinity of the ship for the entire duration of the 
exercise. Additionally, the Navy does not necessarily operate active 
sonar the entire time during an exercise. While it is certainly 
possible that these sorts of exercises could overlap with individual 
marine mammals multiple days in a row at levels above those anticipated 
to result in a take, because of the factors mentioned above, it is 
considered not to be likely for the majority of takes, does not mean 
that a behavioral response is necessarily sustained for multiple days, 
and still necessitates the consideration of likely duration and context 
to assess any effects on the individual's fitness.
    Durations for non-impulsive activities utilizing tactical sonar 
sources vary and are fully described in Appendix A of the FEIS/OEIS. 
ASW training and testing exercises using MFAS/HFAS generally last for 
2-16 hours, and may have intervals of non-activity in between. Because 
of the need to train in a large variety of situations, the Navy does 
not typically conduct successive MTEs or other ASW exercises in the 
same locations. Given the average length of ASW exercises (times of 
continuous sonar use) and typical vessel speed, combined with the fact 
that the majority of the cetaceans in the Study Area would not likely 
remain in an area for successive days, it is unlikely that an animal 
would be exposed to MFAS/HFAS at levels likely to result in a 
substantive response that would then be carried on for more than one 
day or on successive days.
    Most planned explosive exercises are of a short duration (1-6 
hours). Although explosive exercises may sometimes be conducted in the 
same general areas repeatedly, because of their short duration and the 
fact that they are in the open ocean and animals can easily move away, 
it is similarly unlikely that animals would be exposed for long, 
continuous amounts of time.

TTS

    As mentioned previously, TTS can last from a few minutes to days, 
be of varying degree, and occur across various frequency bandwidths, 
all of which determine the severity of the impacts on the affected 
individual, which can range from minor to more severe. The TTS 
sustained by an animal is primarily classified by three 
characteristics:
    1. Frequency--Available data (of mid-frequency hearing specialists 
exposed to mid- or high-frequency sounds; Southall et al., 2007) 
suggest that most TTS occurs in the frequency range of the source up to 
one octave higher than the source (with the maximum TTS at \1/2\ octave 
above). The more powerful MF sources used have center frequencies 
between 3.5 and 8 kHz and the other unidentified MF sources are, by 
definition, less than 10 kHz, which suggests that TTS induced by any of 
these MF sources would be in a frequency band somewhere between 
approximately 2 and 20 kHz. There are fewer hours of HF source use and 
the sounds would attenuate more quickly, plus they have lower source 
levels, but if an animal were to incur TTS from these sources, it would 
cover a higher frequency range (sources are between 20 and 100 kHz, 
which means that TTS could range up to 200 kHz; however, HF

[[Page 46154]]

systems are typically used less frequently and for shorter time periods 
than surface ship and aircraft MF systems, so TTS from these sources is 
even less likely). TTS from explosives would be broadband. Vocalization 
data for each species, which would inform how TTS might specifically 
interfere with communications with conspecifics, was provided in the 
LOA application.
    2. Degree of the shift (i.e., by how many dB the sensitivity of the 
hearing is reduced)--Generally, both the degree of TTS and the duration 
of TTS will be greater if the marine mammal is exposed to a higher 
level of energy (which would occur when the peak dB level is higher or 
the duration is longer). The threshold for the onset of TTS was 
discussed previously in this document. An animal would have to approach 
closer to the source or remain in the vicinity of the sound source 
appreciably longer to increase the received SEL, which would be 
difficult considering the Lookouts and the nominal speed of an active 
sonar vessel (10-15 knots). In the TTS studies, some using exposures of 
almost an hour in duration or up to 217 SEL, most of the TTS induced 
was 15 dB or less, though Finneran et al. (2007) induced 43 dB of TTS 
with a 64-second exposure to a 20 kHz source. However, MFAS emits a 
nominal ping every 50 seconds, and incurring those levels of TTS is 
highly unlikely.
    3. Duration of TTS (recovery time)--In the TTS laboratory studies, 
some using exposures of almost an hour in duration or up to 217 SEL, 
almost all individuals recovered within 1 day (or less, often in 
minutes), although in one study (Finneran et al., 2007), recovery took 
4 days.
    Based on the range of degree and duration of TTS reportedly induced 
by exposures to non-pulse sounds of energy higher than that to which 
free-swimming marine mammals in the field are likely to be exposed 
during MFAS/HFAS training exercises in the Study Area, it is unlikely 
that marine mammals would ever sustain a TTS from MFAS that alters 
their sensitivity by more than 20 dB for more than a few days (and any 
incident of TTS would likely be far less severe due to the short 
duration of the majority of the exercises and the speed of a typical 
vessel). Also, for the same reasons discussed in the Diel Cycle 
section, and because of the short distance within which animals would 
need to approach the sound source, it is unlikely that animals would be 
exposed to the levels necessary to induce TTS in subsequent time 
periods such that their recovery is impeded. Additionally, though the 
frequency range of TTS that marine mammals might sustain would overlap 
with some of the frequency ranges of their vocalization types, the 
frequency range of TTS from MFAS (the source from which TTS would most 
likely be sustained because the higher source level and slower 
attenuation make it more likely that an animal would be exposed to a 
higher received level) would not usually span the entire frequency 
range of one vocalization type, much less span all types of 
vocalizations or other critical auditory cues. If impaired, marine 
mammals would typically be aware of their impairment and are sometimes 
able to implement behaviors to compensate (see Acoustic Masking or 
Communication Impairment section), though these compensations may incur 
energetic costs.

Acoustic Masking or Communication Impairment

    Masking only occurs during the time of the signal (and potential 
secondary arrivals of indirect rays), versus TTS, which continues 
beyond the duration of the signal. Standard MFAS nominally pings every 
50 seconds for hull-mounted sources. For the sources for which we know 
the pulse length, most are significantly shorter than hull-mounted 
active sonar, on the order of several microseconds to tens of 
microseconds. For hull-mounted active sonar, though some of the 
vocalizations that marine mammals make are less than one second long, 
there is only a 1 in 50 chance that they would occur exactly when the 
ping was received, and when vocalizations are longer than one second, 
only parts of them are masked. Alternately, when the pulses are only 
several microseconds long, the majority of most animals' vocalizations 
would not be masked. Masking effects from MFAS/HFAS are expected to be 
minimal. If masking or communication impairment were to occur briefly, 
it would be in the frequency range of MFAS, which overlaps with some 
marine mammal vocalizations; however, it would likely not mask the 
entirety of any particular vocalization, communication series, or other 
critical auditory cue, because the signal length, frequency, and duty 
cycle of the MFAS/HFAS signal does not perfectly mimic the 
characteristics of any marine mammal's vocalizations.

PTS, Injury, or Mortality

    NMFS believes that many marine mammals would deliberately avoid 
exposing themselves to the received levels of active sonar necessary to 
induce injury by moving away from or at least modifying their path to 
avoid a close approach. Additionally, in the unlikely event that an 
animal approaches the sonar vessel at a close distance, NMFS believes 
that the mitigation measures (i.e., shutdown/powerdown zones for MFAS/
HFAS) would typically ensure that animals would not be exposed to 
injurious levels of sound. As discussed previously, the Navy utilizes 
both aerial (when available) and passive acoustic monitoring (during 
all ASW exercises) in addition to watchstanders on vessels to detect 
marine mammals for mitigation implementation.
    If a marine mammal is able to approach a surface vessel within the 
distance necessary to incur PTS, the likely speed of the vessel 
(nominal 10-15 knots) would make it very difficult for the animal to 
remain in range long enough to accumulate enough energy to result in 
more than a mild case of PTS. As mentioned previously and in relation 
to TTS, the likely consequences to the health of an individual that 
incurs PTS can range from mild to more serious, depending upon the 
degree of PTS and the frequency band it is in, and many animals are 
able to compensate for the shift, although it may include energetic 
costs.
    As discussed previously, marine mammals (especially beaked whales) 
could potentially respond to MFAS at a received level lower than the 
injury threshold in a manner that indirectly results in the animals 
stranding. The exact mechanism of this potential response, behavioral 
or physiological, is not known. When naval exercises have been 
associated with strandings in the past, it has typically been when 
three or more vessels are operating simultaneously, in the presence of 
a strong surface duct, and in areas of constricted channels, semi-
enclosed areas, and/or steep bathymetry. A combination of these 
environmental and operational parameters is not present in the MITT 
action. When this is combined with consideration of the number of hours 
of active sonar training that will be conducted and the nature of the 
exercises--which do not typically include the use of multiple hull-
mounted sonar sources--we believe that the probability is small that 
this will occur. Furthermore, given that there has never been a 
stranding in the Study Area associated with sonar use and based on the 
number of occurrences where strandings have been definitively 
associated with military sonar versus the number of hours of active 
sonar training that have been conducted, we believe that the 
probability is small that this will occur as a result of the Navy's 
proposed training and testing activities.

[[Page 46155]]

Lastly, an active sonar shutdown protocol for strandings involving live 
animals milling in the water minimizes the chances that these types of 
events turn into mortalities.
    As stated previously, there have been no recorded Navy vessel 
strikes of any marine mammals during training or testing in the MITT 
Study Area to date, nor were takes by injury or mortality resulting 
from vessel strike predicted in the Navy's analysis.

Important Marine Mammal Habitat

    No critical habitat for marine mammals species protected under the 
ESA has been designated in the MITT Study Area. There are also no known 
specific breeding or calving areas for marine mammals within the MITT 
Study Area.

Group and Species-Specific Analysis

    Predicted harassment of marine mammals from exposures to sonar and 
other active acoustic sources and explosions during annual training and 
testing activities are shown in Table 11. The vast majority of 
predicted exposures are expected to be Level B harassment (non-
injurious TTS and behavioral reactions) from sonar and other active 
acoustic sources at relatively low received levels (less than 156 dB) 
(Table 22). As mentioned earlier in the Analysis and Negligible Impact 
Determination section, an animal's exposure to a higher received level 
is more likely to adversely affect the health of the animal. The 
acoustic analysis predicts the majority of marine mammal species in the 
Study Area would not be exposed to explosive (impulse) sources 
associated with training and testing activities that exceed the 
impulsive sound thresholds for injury (Table 9). Only dwarf sperm 
whale, pygmy sperm whale, Fraser's dolphin, and pantropical spotted 
dolphin are predicted to have Level B (TTS) exposures resulting from 
explosives, and only small numbers of dwarf sperm whales and pygmy 
sperm whales are expected to have injurious take (PTS or minor tissue 
damage from explosives) resulting from sonar and other active acoustic 
sources and explosions. There are no lethal takes predicted for any 
marine mammal species for the MITT activities.
    The analysis below may in some cases (e.g., mysticetes, dolphins) 
address species collectively if they occupy the same functional hearing 
group (i.e., low, mid, and high-frequency cetaceans and pinnipeds in 
water), have similar hearing capabilities, and/or are known to 
generally behaviorally respond similarly to acoustic stressors. Where 
there are meaningful differences between species or stocks, or groups 
of species, in anticipated individual responses to activities, impact 
of expected take on the population due to differences in population 
status, or impacts on habitat, they will either be described within the 
section or the species will be included as a separate sub-section. See 
the Brief Background on Sound section in the proposed rule for a 
description of marine mammal functional hearing groups as originally 
designated by Southall et al. (2007).
    Mysticetes--The Navy's acoustic analysis predicts 1,837 takes 
(Level B harassment) may occur from sonar and other active acoustic 
stressors associated with mostly training and some testing activities 
in the Study Area each year. The acoustic analysis indicates up to 28 
annual instances of Level B harassment (24 TTS and 4 behavioral 
reactions) of fin whales, up to 28 annual instances of Level B 
harassment (25 TTS and 3 behavioral reactions) of blue whales, up to 
319 annual instances of Level B harassment (258 TTS and 61 behavioral 
reactions) of sei whales, up to 860 annual instances of Level B 
harassment (679 TTS and 181 behavioral reactions) of humpback whales, 
up to 398 annual instances of Level B harassment (219 TTS and 79 
behavioral reactions) of Bryde's whales, up to 101 annual instances of 
Level B harassment (81 TTS and 20 behavioral reactions of minke whales, 
and up to 103 annual instances of Level B harassment (84 TTS and 19 
behavioral reactions) of Omura's whales.
    Of these species, humpback, blue, fin, and sei whales are listed as 
endangered under the ESA and depleted under the MMPA. NMFS has 
designated two Pacific stocks for blue whales (Eastern North Pacific 
and Central North Pacific) (Carretta et al., 2014), with blue whales in 
the Study Area most likely part of the Central North Pacific stock. 
NMFS has designated four Pacific stocks for humpback whales (Western 
North Pacific, Central North Pacific, California/Oregon/Washington, and 
American Samoa) (Carretta et al., 2014; Allen and Angliss, 2014), and 
while stock structure is not completely known for the Study Area, it is 
most likely that humpback whales here are part of the Western North 
Pacific and/or Central North Pacific stock. Although NMFS has 
designated Pacific stocks for fin, sei, Bryde's, minke, and Omura's 
whales (Carretta et al., 2014; Allen and Angliss, 2014), little is 
known about the stock structure for these species in the MITT Study 
Area and NMFS currently has not designated any stocks specific to the 
MITT Study Area for these species.
    The estimates given above represent the total number of exposures 
and not necessarily the number of individuals exposed, as a single 
individual may be exposed multiple times over the course of a year. In 
the ocean, the use of sonar and other active acoustic sources is 
transient and is unlikely to repeatedly expose the same population of 
animals over a short period. Around heavily trafficked Navy ports and 
on fixed ranges, the possibility is greater for animals that are 
resident during all or part of the year to be exposed multiple times to 
sonar and other active acoustic sources. However, as discussed in the 
proposed rule, because neither the vessels nor the animals are 
stationary, significant long-term effects from repeated exposure are 
not expected.
    Level B harassment is anticipated to be in the form of non-TTS 
behavioral responses and TTS, and no injurious (Level A harassment) 
takes of mysticete whales from sonar and other active acoustic 
stressors or explosives are expected. The majority of acoustic effects 
to mysticetes from sonar and other active sound sources during training 
and testing activitites would be primarily from anti-submarine warfare 
events involving surface ships and hull mounted (mid-frequency) sonar. 
Research and observations show that if mysticetes are exposed to sonar 
or other active acoustic sources they may react in a number of ways 
depending on the characteristics of the sound source, their experience 
with the sound source, and whether they are migrating or on seasonal 
grounds (i.e., breeding or feeding). Reactions may include alerting, 
breaking off feeding dives and surfacing, diving or swimming away, or 
no response at all (Richardson, 1995; Nowacek, 2007; Southall et al., 
2007). Richardson et al. (1995) noted that avoidance (temporary 
displacement of an individual from an area) reactions are the most 
obvious manifestations of disturbance in marine mammals. It is 
qualitatively different from the startle or flight response, but also 
differs in the magnitude of the response (i.e., directed movement, rate 
of travel, etc.). Oftentimes avoidance is temporary, and animals return 
to the area once the noise has ceased. Additionally, migrating animals 
may ignore a sound source, or divert around the source if it is in 
their path.
    Specific to U.S. Navy systems using low frequency sound, studies 
were undertaken in 1997-98 pursuant to the Navy's Low Frequency Sound 
Scientific Research Program. These studies found only short-term 
responses to low frequency sound by mysticetes (fin, blue, and humpback 
whales) including

[[Page 46156]]

changes in vocal activity and avoidance of the source vessel (Clark, 
2001; Miller et al., 2000; Croll et al., 2001; Fristrup et al., 2003; 
Nowacek et al., 2007). Baleen whales exposed to moderate low-frequency 
signals demonstrated no variation in foraging activity (Croll et al., 
2001). Low-frequency signals of the Acoustic Thermometry of Ocean 
Climate sound source were not found to affect dive times of humpback 
whales in Hawaiian waters (Frankel and Clark, 2000).
    Specific to mid-frequency sound, studies by Melc[oacute]n et al. 
(2012) in the Southern California Bight found that the likelihood of 
blue whale low-frequency calling (usually associated with feeding 
behavior) decreased with an increased level of mid-frequency sonar, 
beginning at a SPL of approximately 110-120 dB re 1 [mu]Pa. However, it 
is not known whether the lower rates of calling actually indicated a 
reduction in feeding behavior or social contact since the study used 
data from remotely deployed, passive acoustic monitoring buoys. 
Preliminary results from the 2010-2011 field season of an ongoing 
behavioral response study in Southern California waters indicated that 
in some cases and at low received levels, tagged blue whales responded 
to mid-frequency sonar but that those responses were mild and there was 
a quick return to their baseline activity (Southall et al., 2012b). 
Blue whales responded to a mid-frequency sound source, with a source 
level between 160 and 210 dB re 1 [mu]Pa at 1 m and a received sound 
level up to 160 dB re 1 [mu]Pa, by exhibiting generalized avoidance 
responses and changes to dive behavior during controlled exposure 
experiments (CEE) (Goldbogen et al., 2013). However, reactions were not 
consistent across individuals based on received sound levels alone, and 
likely were the result of a complex interaction between sound exposure 
factors such as proximity to sound source and sound type (mid-frequency 
sonar simulation vs. pseudo-random noise), environmental conditions, 
and behavioral state. Surface feeding whales did not show a change in 
behavior during CEEs, but deep feeding and non-feeding whales showed 
temporary reactions that quickly abated after sound exposure. Distances 
of the sound source from the whales during CEEs were sometimes less 
than a mile. Furthermore, the more dramatic reactions reported by 
Goldbogen et al. (2013) were from non-sonar like signals, a 
pseudorandom noise that could likely have been a novel signal to blue 
whales. The preliminary findings from Goldbogen et al. (2013) and 
Melc[oacute]n et al. (2012) are generally consistent with the Navy's 
criteria and thresholds for predicting behavioral effects to mysticetes 
from sonar and other active acoustic sources used in the quantitative 
acoustic effects analysis for MITT. The behavioral response function 
predicts a probability of a substantive behavioral reaction for 
individuals exposed to a received SPL of 120 dB re 1 [mu]Pa or greater, 
with an increasing probability of reaction with increased received 
level as demonstrated in Melc[oacute]n et al. (2012).
    High-frequency systems are not within mysticetes' ideal hearing 
range and it is unlikely that they would cause a significant behavioral 
reaction.
    Most Level B harassments to mysticetes from sonar would result from 
received levels less than 156 dB SPL. Therefore, the majority of Level 
B takes are expected to be in the form of milder responses (i.e., 
lower-level exposures that still rise to the level of take, but would 
likely be less severe in the range of responses that qualify as take) 
of a generally short duration. As mentioned earlier in the Analysis and 
Negligible Impact Determination section, we anticipate more severe 
effects from takes when animals are exposed to higher received levels. 
Most low-frequency (mysticetes) cetaceans observed in studies usually 
avoided sound sources at levels of less than or equal to 160 dB re 
1[mu]Pa. Occasional behavioral reactions are unlikely to cause long-
term consequences for individual animals or populations. Even if sound 
exposure were to be concentrated in a relatively small geographic area 
over a long period of time (e.g., days or weeks during major training 
exercises), we would expect that some individual whales would avoid 
areas where exposures to acoustic stressors are at higher levels. For 
example, Goldbogen et al. (2013) indicated some horizontal displacement 
of deep foraging blue whales in response to simulated MFA sonar. Given 
these animal's mobility and large ranges, we would expect these 
individuals to temporarily select alternative foraging sites nearby 
until the exposure levels in their initially selected foraging area 
have decreased. Therefore, even temporary displacement from initially 
selected foraging habitat is not expected to impact the fitness of any 
individual animals because we would expect equivalent foraging to be 
available in close proximity. Because we do not expect any fitness 
consequences from any individual animals, we do not expect any 
population level effects from these behavioral responses.
    As explained above, recovery from a threshold shift (TTS) can take 
a few minutes to a few days, depending on the exposure duration, sound 
exposure level, and the magnitude of the initial shift, with larger 
threshold shifts and longer exposure durations requiring longer 
recovery times (Finneran et al., 2005; Finneran and Schlundt, 2010; 
Mooney et al., 2009a; Mooney et al., 2009b). However, large threshold 
shifts are not anticipated for these activities because of the 
unlikelihood that animals will remain within the ensonified area (due 
to the short duration of the majority of exercises, the speed of the 
vessels, and the short distance within which the animal would need to 
approach the sound source) at high levels for the duration necessary to 
induce larger threshold shifts. Threshold shifts do not necessarily 
affect all hearing frequencies equally, so some threshold shifts may 
not interfere with an animal's hearing of biologically relevant sounds. 
Furthermore, the implementation of mitigation and the sightability of 
mysticetes (due to their large size) reduces the potential for a 
significant behavioral reaction or a threshold shift to occur.
    There has never been a vessel strike to a whale during any active 
training or testing activities in the Study Area. A detailed analysis 
of strike data is contained in Chapter 6 (Section 6.3.4, Estimated Take 
of Large Whales by Navy Vessel Strike) of the LOA application. The Navy 
does not anticipate vessel strikes to marine mammals during training or 
testing activities within the Study Area, nor were takes by injury or 
mortality resulting from vessel strike predicted in the Navy's 
analysis. Therefore, NMFS is not authorizing mysticete takes (by injury 
or mortality) from vessel strikes during the 5-year period of the MITT 
regulations.
    There is no designated critical habitat for mysticetes in the Study 
Area. There are also no areas of specific importance for reproduction, 
calving, or feeding for mysticetes in the Study Area.
    Sperm Whales--The Navy's acoustic analysis indicates that 506 
instances of Level B harassment of sperm whales may occur each year 
from sonar or other active acoustic stressors during training and 
testing activities. These Level B takes are anticipated to be in the 
form of TTS (54) and behavioral reactions (452) and no injurious takes 
of sperm whales from sonar and other active acoustic stressors or 
explosives are requested or proposed for authorization. Although NMFS 
has designated Pacific stocks for sperm whales (Carretta et al., 2014; 
Allen and Angliss, 2014), little is known about the stock structure for 
this species in the MITT Study Area and NMFS currently has not 
designated any

[[Page 46157]]

sperm whale stocks specific to the MITT Study Area.
    Sperm whales have shown resilience to acoustic and human 
disturbance, although they may react to sound sources and activities 
within a few kilometers. Sperm whales that are exposed to activities 
that involve the use of sonar and other active acoustic sources may 
alert, ignore the stimulus, avoid the area by swimming away or diving, 
or display aggressive behavior (Richardson, 1995; Nowacek, 2007; 
Southall et al., 2007). Some (but not all) sperm whale vocalizations 
might overlap with the MFAS/HFAS TTS frequency range, which could 
temporarily decrease an animal's sensitivity to the calls of 
conspecifics or returning echolocation signals. However, as noted 
previously, NMFS does not anticipate TTS of a long duration or severe 
degree to occur as a result of exposure to MFAS/HFAS. Recovery from a 
threshold shift (TTS) can take a few minutes to a few days, depending 
on the exposure duration, sound exposure level, and the magnitude of 
the initial shift, with larger threshold shifts and longer exposure 
durations requiring longer recovery times (Finneran et al., 2005; 
Finneran and Schlundt, 2010; Mooney et al., 2009a; Mooney et al., 
2009b). However, large threshold shifts are not anticipated for these 
activities because of the unlikelihood that animals will remain within 
the ensonified area (due to the short duration of the majority of 
exercises and the speed of the vessels) at high levels for the duration 
necessary to induce larger threshold shifts. Also, because of the short 
distance within which animals would need to approach the sound source, 
it is unlikely that animals would be exposed to the levels necessary to 
induce TTS in subsequent time periods such that their recovery is 
impeded. Threshold shifts do not necessarily affect all hearing 
frequencies equally, so some threshold shifts may not interfere with an 
animal's hearing of biologically relevant sounds. No sperm whales are 
predicted to be exposed to MFAS/HFAS sound levels associated with PTS 
or injury.
    The majority of Level B takes are expected to be in the form of 
milder responses (low-level exposures) and of a generally short 
duration. Overall, the number of predicted behavioral reactions are 
unlikely to cause long-term consequences for individual animals or 
populations. The MITT activities are not expected to occur in an area/
time of specific importance for reproductive, feeding, or other known 
critical behaviors for sperm whales. Consequently, the activities are 
not expected to adversely impact rates of recruitment or survival of 
sperm whales. Sperm whales are listed as endangered under the ESA (and 
depleted under the MMPA); however, there is no designated critical 
habitat in the Study Area.
    There has never been a vessel strike to a sperm whale during any 
active training or testing activities in the Study Area. A detailed 
analysis of strike data is contained in Chapter 6 (Section 6.3.4, 
Estimated Take of Large Whales by Navy Vessel Strike) of the LOA 
application. The Navy does not anticipate vessel strikes to marine 
mammals during training or testing activities within the Study Area, 
nor were takes by injury or mortality resulting from vessel strike 
predicted in the Navy's analysis. Therefore, NMFS is not authorizing 
sperm whale takes (by injury or mortality) from vessel strikes during 
the 5-year period of the MITT regulations.
    Pygmy and Dwarf Sperm Whale--The Navy's acoustic analysis predicts 
Level B harassment (non-TTS behavioral responses and TTS) of 5,579 
pygmy sperm whales and 14,217 dwarf sperm whales may occur annually 
from sonar and other active acoustic stressors and explosives 
associated with training and testing activities in the Study Area. 
These estimates represents the total number of exposures and not 
necessarily the number of individuals exposed, as a single individual 
may be exposed multiple times over the course of a year. Of the Level B 
takes, 5,467 pygmy sperm whale and 13,901 dwarf sperm whale takes are 
predicted to be in the form of TTS from mainly MFAS/HFAS. The Navy's 
acoustic analysis (factoring in the post-model correction for avoidance 
and mitigation) also indicates that 15 injurious (Level A harassment) 
takes of pygmy sperm whale and 41 injurious (Level A harassment) takes 
of dwarf sperm whale may occur annually from active sonar.
    Although NMFS has designated Pacific stocks for pygmy and dwarf 
sperm whales (Carretta et al., 2014), little is known about the stock 
structure for these species in the MITT Study Area and NMFS currently 
has not designated any pygmy and dwarf sperm whale stocks specific to 
the MITT Study Area.
    Recovery from a threshold shift (TTS; partial hearing loss) can 
take a few minutes to a few days, depending on the exposure duration, 
sound exposure level, and the magnitude of the initial shift, with 
larger threshold shifts and longer exposure durations requiring longer 
recovery times (Finneran et al., 2005; Mooney et al., 2009a; Mooney et 
al., 2009b; Finneran and Schlundt, 2010). An animal incurring PTS would 
not fully recover. However, large degrees of threshold shifts (PTS or 
TTS) are not anticipated for these activities because of the 
unlikelihood that animals will remain within the ensonified area (due 
to the short duration of the majority of exercises, the speed of the 
vessels, and the short distance within which the animal would need to 
approach the sound source) at high levels for the duration necessary to 
induce larger threshold shifts. Threshold shifts do not necessarily 
affect all hearing frequencies equally, so some threshold shifts may 
not interfere with an animal hearing biologically relevant sounds. The 
likely consequences to the health of an individual that incurs PTS can 
range from mild to more serious, depending upon the degree of PTS and 
the frequency band it is in, and many animals are able to compensate 
for the shift, although it may include energetic costs. Furthermore, 
likely avoidance of intense activity and sound coupled with mitigation 
measures would further reduce the potential for more-severe PTS 
exposures to occur. If a pygmy or dwarf sperm whale is able to approach 
a surface vessel within the distance necessary to incur PTS, the likely 
speed of the vessel (nominal 10-15 knots) would make it very difficult 
for the animal to remain in range long enough to accumulate enough 
energy to result in more than a mild case of PTS. Some Kogia spp. 
vocalizations might overlap with the MFAS/HFAS TTS frequency range (2-
20 kHz), but the limited information for Kogia spp. indicates that 
their clicks are at a much higher frequency and that their maximum 
hearing sensitivity is between 90 and 150 kHz.
    Research and observations on Kogia spp. are limited. These species 
tend to avoid human activity and presumably anthropogenic sounds. Pygmy 
and dwarf sperm whales may startle and leave the immediate area of 
activity, reducing potential impacts. Pygmy and dwarf sperm whales have 
been observed to react negatively to survey vessels or low altitude 
aircraft by quick diving and other avoidance maneuvers, and none were 
observed to approach vessels (Wursig et al., 1998). Based on their 
tendency to avoid acoustic stressors (e.g., quick diving and other 
vertical avoidance maneuvers) coupled with the short duration and 
intermittent nature (e.g., sonar pings during ASW activities occur 
about every 50 seconds) of the majority of training and testing 
exercises and the speed of the Navy vessels

[[Page 46158]]

involved, it is unlikely that animals would receive multiple exposures 
over a short period of time, allowing animals to recover lost resources 
(e.g., food) or opportunities (e.g., mating).
    It is worth noting that the amount of explosive and acoustic energy 
entering the water may be overestimated, as many explosions actually 
occur upon impact with above-water targets. However, sources such as 
these were modeled as exploding at 1-meter depth.
    The predicted effects to Kogia spp. are expected to be mostly 
temporary and unlikely to cause long-term consequences for individual 
animals or populations. The MITT activities are not expected to occur 
in an area/time of specific importance for reproductive, feeding, or 
other known critical behaviors. Pacific stocks of Kogia are not 
depleted under the MMPA. Consequently, the activities are not expected 
to adversely impact rates of recruitment or survival of pygmy and dwarf 
sperm whales.
    Beaked Whales--The Navy's acoustic analysis predicts Level B 
harassment of four species of beaked whale annually: 22,541 Cuvier's 
beaked whales; 4,426 Blainville's beaked whale; 1,924 Longman's beaked 
whale; and 3,897 ginko-toothed beaked whales. These estimates represent 
the total number of exposures and not necessarily the number of 
individuals exposed, as a single individual may be exposed multiple 
times over the course of a year. These takes are anticipated to be in 
the form of mainly non-TTS behavioral harassment and some TTS, and no 
injurious takes of beaked whales from sonar and active acoustic 
stressors or explosives were predicted. Of the Level B takes, 308 
Cuvier's beaked whale, 73 Blainville's beaked whale, 29 Longman's 
beaked whale, and 62 ginko-toothed beaked whale takes are predicted to 
be in the form of TTS from sonar and other active acoustic sources. 
Although NMFS has designated Pacific stocks for Cuvier's, Blainville's, 
and Longman's beaked whales (Carretta et al., 2014; Allen and Angliss, 
2014), little is known about the stock structure for beaked whales in 
the MITT Study Area and NMFS currently has not designated any beaked 
whale stocks specific to the MITT Study Area.
    Of note, the number of beaked whales behaviorally harassed by 
exposure to MFAS/HFAS is generally higher than the other species 
because of the low Level B harassment threshold, which essentially 
makes the ensonified area of effects significantly larger than for the 
other species. Beaked whales have unique criteria based on specific 
data that show these animals to be especially sensitive to sound 
(McCarthy et al., 2011; Tyack et al., 2011). Beaked whale non-impulsive 
behavioral criteria are used unweighted (i.e., without weighting the 
received level before comparing it to the threshold (see Finneran and 
Jenkins, 2012)). The Navy has adopted an unweighted 140 dB re 1 
[micro]Pa SPL threshold for significant behavioral effects for all 
beaked whales. The fact that the threshold is a step function and not a 
curve (and assuming uniform density) means that the vast majority of 
the takes occur in the very lowest levels that exceed the threshold (it 
is estimated that approximately 80 percent of the takes are from 
exposures of 140 dB to 146 dB), which means that the anticipated 
effects for the majority of exposures are not expected to be severe (As 
mentioned above, an animal's exposure to a higher received level is 
more likely to result in a behavioral response that is more likely to 
adversely affect the health of an animal). Further, Moretti et al. 
(2014) recently derived an empirical risk function for Blainville's 
beaked whale that predicts there is a 0.5 probability of disturbance at 
a received level of 150 dB (CI: 144-155), suggesting that in some cases 
the current Navy step function over-estimate the effects of an activity 
using sonar on beaked whales. Irrespective of the Moretti et al. (2014) 
risk function, NMFS' analysis assumes that all of the beaked whale 
Level B takes that are proposed for authorization will occur, and we 
base our negligible impact determination, in part, on the fact that 
these exposures would mainly occur at the very lowest end of the 140-dB 
behavioral harassment threshold where behavioral effects are expected 
to be much less severe and generally temporary in nature.
    Behavioral responses of beaked whales can range from a mild 
orienting response, or a shifting of attention, to flight and panic 
(Richardson, 1995; Nowacek, 2007; Southall et al., 2007; Finneran and 
Jenkins, 2012). Research has also shown that beaked whales are 
sensitive to the presence of human activity (Tyack et al., 2011; 
Pirotta et al., 2012). Beaked whales have been documented to exhibit 
avoidance of human activity or respond to vessel presence (Pirotta et 
al., 2012). Beaked whales were observed to react negatively to survey 
vessels or low altitude aircraft by quick diving and other avoidance 
maneuvers, and none were observed to approach vessels (Wursig et al., 
1998). Some beaked whale vocalizations may overlap with the MFAS/HFAS 
TTS frequency range (2-20 kHz); however, as noted above, NMFS does not 
anticipate TTS of a serious degree or extended duration to occur as a 
result of exposure to MFA/HFAS. Recovery from a threshold shift (TTS) 
can take a few minutes to a few days, depending on the exposure 
duration, sound exposure level, and the magnitude of the initial shift, 
with larger threshold shifts and longer exposure durations requiring 
longer recovery times (Finneran et al., 2005; Finneran and Schlundt, 
2010; Mooney et al., 2009a; Mooney et al., 2009b). However, large 
threshold shifts are not anticipated for these activities because of 
the unlikelihood that animals will remain within the ensonified area 
(due to the short duration of the majority of exercises, the speed of 
the vessels, and the short distance within which the animal would need 
to approach the sound source) at high levels for the duration necessary 
to induce larger threshold shifts. Threshold shifts do not necessarily 
affect all hearing frequencies equally, so some threshold shifts may 
not interfere with an animal's hearing of biologically relevant sounds.
    No beaked whales are predicted in the acoustic analysis to be 
exposed to sound levels associated with PTS, other injury, or 
mortality. After decades of the Navy conducting similar activities in 
the MITT Study Area without incident, NMFS does not expect stranding, 
injury, or mortality of beaked whales to occur as a result of Navy 
activities. Therefore, NMFS is not authorizing any Level A (injury or 
mortality) takes for beaked whales. Additionally, through the MMPA 
process (which allows for adaptive management), NMFS and the Navy will 
determine the appropriate way to proceed in the event that a causal 
relationship were to be found between Navy activities and a future 
stranding.
    NMFS also considered New et al. (2013) and their mathematical model 
simulating a functional link between foraging energetics and 
requirements for survival and reproduction for 21 species of beaked 
whales. However, NMFS concluded that the New et al. (2013) model lacks 
critical data and accurate inputs necessary to form valid conclusions 
specifically about impacts of anthropogenic sound from Navy activities 
on specific beaked whale populations. The study itself notes the need 
for ``future research,'' identifies ``key data needs'' relating to 
input parameters that ``particularly affected'' the model results, and 
states only that the use of the model ``in combination with more 
detailed research'' could help predict the effects of management 
actions on beaked whale species. In short, information is not currently 
available to specifically support the use

[[Page 46159]]

of this model in a project-specific evaluation of the effects of Navy 
activities on the impacted beaked whale species in MITT.
    It has been speculated for some time that beaked whales might have 
unusual sensitivities to sonar sound due to their likelihood of 
stranding in conjunction with mid-frequency sonar use. Research and 
observations show that if beaked whales are exposed to sonar or other 
active acoustic sources they may startle, break off feeding dives, and 
avoid the area of the sound source to levels of 157 dB re 1 [micro]Pa, 
or below (McCarthy et al., 2011). Acoustic monitoring during actual 
sonar exercises revealed some beaked whales continuing to forage at 
levels up to 157 dB re 1 [micro]Pa (Tyack et al. 2011). Stimpert et al. 
(2014) tagged a Baird's beaked whale, which was subsequently exposed to 
simulated mid-frequency sonar. Received levels of sonar on the tag 
increased to a maximum of 138 dB re 1[mu]Pa, which occurred during the 
first exposure dive. Some sonar received levels could not be measured 
due to flow noise and surface noise on the tag. Manzano-Roth et al. 
(2013) found that for beaked whale dives that continued to occur during 
MFAS activity, differences from normal dive profiles and click rates 
were not detected with estimated received levels up to 137 dB re 1 
[micro]Pa while the animals were at depth during their dives. In 
research done at the Navy's fixed tracking range in the Bahamas, 
animals were observed to leave the immediate area of the anti-submarine 
warfare training exercise (avoiding the sonar acoustic footprint at a 
distance where the received level was ``around 140 dB'' SPL, according 
to Tyack et al. [2011]) but return within a few days after the event 
ended (Claridge and Durban, 2009; Moretti et al., 2009, 2010; Tyack et 
al., 2010, 2011; McCarthy et al., 2011). Tyack et al. (2011) report 
that, in reaction to sonar playbacks, most beaked whales stopped 
echolocating, made long slow ascent to the surface, and moved away from 
the sound. A similar behavioral response study conducted in Southern 
California waters during the 2010-2011 field season found that Cuvier's 
beaked whales exposed to MFAS displayed behavior ranging from initial 
orientation changes to avoidance responses characterized by energetic 
fluking and swimming away from the source (DeRuiter et al., 2013). 
However, the authors did not detect similar responses to incidental 
exposure to distant naval sonar exercises at comparable received 
levels, indicating that context of the exposures (e.g., source 
proximity, controlled source ramp-up) may have been a significant 
factor. The study itself found the results inconclusive and meriting 
further investigation.
    Populations of beaked whales and other odontocetes in the Bahamas 
and other Navy fixed ranges that have been operating for tens of years 
appear to be stable. Significant behavioral reactions seem likely in 
most cases if beaked whales are exposed to anti-submarine sonar within 
a few tens of kilometers, especially for prolonged periods (a few hours 
or more), since this is one of the most sensitive marine mammal groups 
to anthropogenic sound of any species or group studied to date and 
research indicates beaked whales will leave an area where anthropogenic 
sound is present (Tyack et al., 2011; De Ruiter et al., 2013; Manzano-
Roth et al., 2013; Moretti et al., 2014). Research involving tagged 
Cuvier's beaked whales in the SOCAL Range Complex reported on by 
Falcone and Schorr (2012, 2014) indicates year-round prolonged use of 
the Navy's training and testing area by these beaked whales and has 
documented movements in excess of hundreds of kilometers by some of 
those animals. Given that some of these animals may routinely move 
hundreds of kilometers as part of their normal pattern, leaving an area 
where sonar or other anthropogenic sound is present may have little, if 
any, cost to such an animal. Photo identification studies in the SOCAL 
Range Complex, a Navy range that is utilized for training and testing 
more frequently than the MITT Study Area, have identified approximately 
100 Cuvier's beaked whale individuals with 40 percent having been seen 
in one or more prior years, with re-sightings up to seven years apart 
(Falcone and Schorr, 2014). These results indicate long-term residency 
by individuals in an intensively used Navy training and testing area, 
which may also suggest a lack of long-term consequences as a result of 
exposure to Navy training and testing activities. Finally, results from 
passive acoustic monitoring estimated regional Cuvier's beaked whale 
densities were higher than indicated by the NMFS's broad scale visual 
surveys for the U.S. west coast (Hildebrand and McDonald, 2009). Based 
on the findings above, it is clear that the Navy's long-term ongoing 
use of sonar and other active acoustic sources has not precluded beaked 
whales from also continuing to inhabit those areas.
    In summary, based on the best available science, the Navy and NMFS 
believe that beaked whales that exhibit a significant TTS or behavioral 
reaction due to sonar and other active acoustic testing activities 
would generally not have long-term consequences for individuals or 
populations. Claridge (2013) speculates that sonar use in a Bahamas 
range could have ``a possible population-level effect'' on beaked 
whales based on lower abundance in comparison to control sites. 
However, the study suffers from several shortcomings and incorrectly 
assumes that the Navy range and control sites were identical. The 
author also acknowledged that ``information currently available cannot 
provide a quantitative answer to whether frequent sonar use at [the 
Bahamas range] is causing stress to resident beaked whales,'' and 
cautioned that the outcome of ongoing studies ``is a critical component 
to understanding if there are population-level effects.'' Moore and 
Barlow (2013) have noted a decline in beaked whale populations in a 
broad area of the Pacific Ocean area out to 300 nm from the coast and 
extending from the Canadian-U.S. border to the tip of Baja Mexico. 
There are scientific caveats and limitations to the data used for that 
analysis, as well as oceanographic and species assemblage changes on 
the U.S. Pacific coast not thoroughly addressed. Interestingly, 
however, in the small portion of that area overlapping the Navy's SOCAL 
Range Complex, long-term residency by individual Cuvier's beaked whales 
and higher densities provide indications that the proposed decline 
noted elsewhere is not apparent where the Navy has been intensively 
training and testing with sonar and other systems for decades.
    There is no direct evidence that routine Navy training and testing 
spanning decades has negatively impacted marine mammal populations at 
any Navy range complex. In at least three decades of similar 
activities, only one instance of injury to marine mammals (March 4, 
2011; three long-beaked common dolphin at Silver Strand Training 
Complex) has been documented as a result of training or testing using 
an impulse source (underwater explosion) and the Navy implemented more 
stringent mitigation measures as a result of this incident. Stranding 
events coincident with Navy MFAS use in which exposure to sonar is 
believed to have been a contributing factor were detailed in the 
Stranding and Mortality section of the proposed rule (FR 79 15437). 
However, for some of these stranding events, a causal relationship 
between sonar exposure and the stranding could not be clearly 
established (Cox et al., 2006). In other instances, sonar was 
considered only one of several factors that, in their

[[Page 46160]]

aggregate, may have contributed to the stranding event (Freitas, 2004; 
Cox et al., 2006). On March 24, 2015, a Cuvier's beaked whale stranded, 
and eventually died, near Bile Bay, Merizo Guam. The Navy confirmed 
that non-MTE sonar exercises took place in the MIRC from March 23-27, 
2015. A necropsy was performed by the Guam Department of Agriculture, 
Division of Aquatics and Wildlife with assistance from NOAA. Results of 
the necropsy have yet to be released and no causal relationship between 
the stranding and Navy activities has been determined at this time.
    Because of the association between tactical MFA sonar use and a 
small number of marine mammal strandings, the Navy and NMFS have been 
considering and addressing the potential for strandings in association 
with Navy activities for years. In addition to a suite of mitigation 
measures intended to more broadly minimize impacts to marine mammals, 
the Navy and NMFS have a detailed Stranding Response Plan that outlines 
reporting, communication, and response protocols intended both to 
minimize the impacts of, and enhance the analysis of, any potential 
stranding in areas where the Navy operates.
    The MITT training and testing activities are not expected to occur 
in an area/time of specific importance for reproductive, feeding, or 
other known critical behaviors for beaked whales. The degree of 
predicted Level B harassment is expected to be mild, and no beaked 
whales are predicted in the acoustic analysis to be exposed to sound 
levels associated with PTS, other injury, or mortality. Consequently, 
the activities are not expected to adversely impact rates of 
recruitment or survival of beaked whales.
    Social Pelagic Species (Small Whales)--The Navy's acoustic analysis 
predicts that the following numbers of Level B behavioral harassments 
of the associated species will occur annually: 84 killer whales; 555 
false killer whales; 105 pygmy killer whales; 1,815 short-finned pilot 
whales; and 2,085 melon-headed whales; including the following numbers 
of TTS, respectively: 15, 101, 19, 334, and 448. These estimates 
represent the total number of exposures and not necessarily the number 
of individuals exposed, as a single individual may be exposed multiple 
times over the course of a year. Behavioral responses of social pelagic 
small whales can range from a mild orienting response, or a shifting of 
attention, to flight and panic (Richardson, 1995; Nowacek, 2007; 
Southall et al., 2007; Finneran and Jenkins, 2012). No injurious takes 
from active acoustic stressors or explosives are requested or proposed 
for authorization.
    Although NMFS has designated Pacific stocks for killer whales, 
false killer whales, pygmy killer whales, short-finned pilot whales, 
and melon-headed whales (Carretta et al., 2014; Allen and Angliss, 
2014), little is known about the stock structure for these species in 
the MITT Study Area and NMFS currently has not designated any stocks 
for these species specific to the MITT Study Area.
    As mentioned previously, TTS from MFAS is anticipated to occur 
primarily in the 2-20 kHz range. If any individuals of these species 
were to experience TTS from MFAS/HFAS, the TTS would likely overlap 
with some of the vocalizations of conspecifics, and not with others. 
However, as noted previously, NMFS does not anticipate TTS of a long 
duration or severe degree to occur as a result of exposure to MFA/HFAS. 
Recovery from a threshold shift (TTS) can take a few minutes to a few 
days, depending on the exposure duration, sound exposure level, and the 
magnitude of the initial shift, with larger threshold shifts and longer 
exposure durations requiring longer recovery times (Finneran et al., 
2005; Finneran and Schlundt, 2010; Mooney et al., 2009a; Mooney et al., 
2009b). However, large threshold shifts are not anticipated for these 
activities because of the unlikelihood that animals will remain within 
the ensonified area (due to the short duration of the majority of 
exercises, the speed of the vessels, and the short distance within 
which the animal would need to approach the sound source) at high 
levels for the duration necessary to induce larger threshold shifts. 
Threshold shifts do not necessarily affect all hearing frequencies 
equally, so some threshold shifts may not interfere with an animal's 
hearing of biologically relevant sounds.
    Controlled exposure experiments in 2007 and 2008 in the Bahamas 
recorded responses of false killer whales, short-finned pilot whales, 
and melon-headed whales to simulated MFA sonar (De Ruiter et al., 
2013). The responses to exposures between species were variable. After 
hearing each MFAS signal, false killer whales were found to ``increase 
their whistle production rate and made more-MFAS-like whistles'' (De 
Ruiter et al., 2013). In contrast, melon-headed whales had ``minor 
transient silencing'' after each MFAS signal, while pilot whales had no 
apparent response.
    Pilot whales or false killer whales in the Bahamas showed an 
avoidance response to controlled exposure playbacks (Southall et al., 
2009). Consistent with the findings of other previous research (see, 
for example Southall et al., 2007), De Ruiter et al., (2013b) found the 
responses were variable by species and with the context of the sound 
exposure. The assumption is that odontocete species in general, 
including those in the MITT Study Area, would have similar variable 
responses.
    Research and observations show that if killer whales are exposed to 
sonar or other active acoustic sources they may react in a number of 
ways depending on their experience with the sound source and what 
activity they are engaged in at the time of the acoustic exposure. 
Killer whales may not react at all until the sound source is 
approaching within a few hundred meters to within a few kilometers 
depending on the environmental conditions and species. Killer whales 
that are exposed to activities that involve the use of sonar and other 
active acoustic sources may alert, ignore the stimulus, change their 
behaviors or vocalizations, avoid the sound source by swimming away or 
diving, or be attracted to the sound source. Research has demonstrated 
that killer whales may routinely move over long large distances 
(Andrews and Matkin, 2014; Fearnbach et al., 2013). In a similar 
documented long-distance movement, an Eastern North Pacific Offshore 
stock killer whale tagged off San Clemente Island, California, moved 
(over a period of 147 days) to waters off northern Mexico, then north 
to Cook Inlet, Alaska, and finally (when the tag ceased transmitting) 
to coastal waters off Southeast Alaska (Falcone and Schorr, 2014). 
Given these findings, temporary displacement due to avoidance of 
training and testing activities are therefore unlikely to have 
biological significance to individual animals. Long-term consequences 
to individual killer whales or populations are not likely due to 
exposure to sonar or other active acoustic sources. Population-level 
consequences are not expected.
    The MITT activities are not expected to occur in an area/time of 
specific importance for reproductive, feeding, or other known critical 
behaviors for social pelagic species. Consequently, the activities are 
not expected to adversely impact rates of recruitment or survival of 
these species.
    Dolphins--The Navy's acoustic analysis predicts the following 
numbers of Level B harassment annually: 741 bottlenose dolphin; 12,811 
pantropical spotted dolphin; 3,298 striped dolphin; 589 spinner 
dolphin; 1,819 rough toothed dolphin; 2,572 Fraser's dolphin;

[[Page 46161]]

and 505 Risso's dolphin. These estimates represent the total number of 
exposures and not necessarily the number of individuals exposed, as a 
single individual may be exposed multiple times over the course of a 
year. The majority of takes are anticipated to be by non-TTS behavioral 
harassment in the form of milder responses (low received levels and of 
a short duration) to sonar and other active acoustic sources. No 
injurious takes of dolphins from active acoustic stressors or 
explosives are requested or proposed for authorization. Behavioral 
responses can range from alerting, to changing their behavior or 
vocalizations, to avoiding the sound source by swimming away or diving 
(Richardson, 1995; Nowacek, 2007; Southall et al., 2007).
    Of the Level B takes, 150 bottlenose dolphin; 2,584 pantropical 
spotted dolphin; 612 striped dolphin; 119 spinner dolphin; 377 rough 
toothed dolphin; 493 Fraser's dolphin; and 84 Risso's dolphin takes are 
predicted to be in the form of generally mild TTS from sonar and other 
active acoustic sources. Though the group size and behavior of these 
species makes it likely that Navy lookouts would detect them and 
implement shutdown if appropriate, the proposed mitigation has a 
provision that allows the Navy to continue operation of MFAS if the 
animals are clearly bow-riding even after the Navy has initially 
maneuvered to try and avoid closing with the animals. As mentioned 
above, many of the recorded dolphin vocalizations overlap with the 
MFAS/HFAS TTS frequency range (2-20 kHz), however, as noted above, NMFS 
does not anticipate TTS of a serious degree or extended duration to 
occur. Recovery from a threshold shift (TTS) can take a few minutes to 
a few days, depending on the exposure duration, sound exposure level, 
and the magnitude of the initial shift, with larger threshold shifts 
and longer exposure durations requiring longer recovery times (Finneran 
et al., 2005; Finneran and Schlundt, 2010; Mooney et al., 2009a; Mooney 
et al., 2009b). However, large threshold shifts are not anticipated for 
these activities because of the unlikelihood that animals will remain 
within the ensonified area (due to the short duration of the majority 
of exercises, the speed of the vessels, and the short distance within 
which the animal would need to approach the sound source) at high 
levels for the duration necessary to induce larger threshold shifts. 
Threshold shifts do not necessarily affect all hearing frequencies 
equally, so some threshold shifts may not interfere with an animal's 
hearing of biologically relevant sounds.
    One Level B take each for Fraser's dolphin and pantropical spotted 
dolphin is predicted to be in the form of non-injurious TTS from 
impulsive sound sources (explosive detonations). Research and 
observations suggest that if delphinids are exposed to impulse sound 
sources, they may react by alerting, ignoring the stimulus, changing 
their behavior or vocalizations, or avoiding the area by swimming away 
or diving (Richardson, 1995; Finneran, 2002; Madsen et al., 2006; Weir, 
2008; and Miller et al., 2009).
    Although NMFS has designated Pacific stocks for bottlenose, 
pantropical spotted, striped, spinner, rough toothed, Fraser's, and 
Risso's dolphins (Carretta et al., 2014), little is known about the 
stock structure for these species in the MITT Study Area and NMFS 
currently has not designated any stocks for these species specific to 
the MITT Study Area.
    The MITT activities are not expected to occur in an area/time of 
specific importance for reproductive, feeding, or other known critical 
behaviors for dolphins. Consequently, the activities are not expected 
to adversely impact rates of recruitment or survival of these species.

Long-Term Consequences

    The best assessment of long-term consequences from training and 
testing activities will be to monitor the populations over time within 
a given Navy range complex. A U.S. workshop on Marine Mammals and Sound 
(Fitch et al., 2011) indicated a critical need for baseline biological 
data on marine mammal abundance, distribution, habitat, and behavior 
over sufficient time and space to evaluate impacts from human-generated 
activities on long-term population survival. The Navy has developed 
monitoring plans for protected marine mammals occurring on Navy ranges 
with the goal of assessing the impacts of training and testing 
activities on marine species and the effectiveness of the Navy's 
current mitigation practices. Continued monitoring efforts over time 
will be necessary to completely evaluate the long-term consequences of 
exposure to noise sources.
    Since 2006 across all Navy range complexes (in the Atlantic, Gulf 
of Mexico, and the Pacific), there have been more than 80 reports; 
Major Exercise Reports, Annual Exercise Reports, and Monitoring 
Reports. For the Pacific since 2011, there have been 29 monitoring and 
exercise reports submitted to NMFS to further research goals aimed at 
understanding the Navy's impact on the environment as it carries out 
its mission to train and test (www.navymarinespeciesmonitoring.us).
    In addition to this multi-year record of reports from across the 
Navy, there have also been ongoing Behavioral Response Study research 
efforts (in Southern California and the Bahamas) specifically focused 
on determining the potential effects from Navy mid-frequency sonar 
(Southall et al., 2011, 2012; Tyack et al., 2011; DeRuiter et al., 
2013b; Goldbogen et al., 2013; Moretti et al., 2014). This multi-year 
compendium of monitoring, observation, study, and broad scientific 
research is informative with regard to assessing the effects of Navy 
training and testing in general. Given that this record involves many 
of the same Navy training and testing activities being considered for 
the Study Area and because it includes all the marine mammal taxonomic 
families and many of the same species, this compendium of Navy 
reporting is directly applicable to assessing locations such as the 
Mariana Islands.
    In the Hawaii and Southern California Navy training and testing 
ranges from 2009 to 2012, Navy-funded marine mammal monitoring research 
completed over 5,000 hours of visual survey effort covering over 65,000 
nautical miles, sighted over 256,000 individual marine mammals, took 
over 45,600 digital photos and 36 hours of digital video, attached 70 
satellite tracking tags to individual marine mammals, and collected 
over 40,000 hours of passive acoustic recordings. In Hawaii alone 
between 2006 and 2012, there were 21 scientific marine mammal surveys 
conducted before, during, or after major exercises.
    Based on monitoring conducted before, during, and after Navy 
training and testing events since 2006, the NMFS' assessment is that it 
is unlikely there will be impacts having any long-term consequences to 
populations of marine mammals as a result of the proposed continuation 
of training and testing in the ocean areas historically used by the 
Navy including the MITT Study Area. This assessment of likelihood is 
based on four indicators from areas in the Pacific where Navy training 
and testing has been ongoing for decades: (1) Evidence suggesting or 
documenting increases in the numbers of marine mammals present 
(Calambokidis and Barlow, 2004; Falcone et al., 2009; Hildebrand and 
McDonald, 2009; Falcone and Shorr, 2012; Calambokidis et al., 2009a; 
Berman-Kowalewski et al., 2010; Moore and Barlow, 2011; Barlow et al. 
2011; Kerosky et al,. 2012; Smultea et al., 2013), or evidence 
suggesting

[[Page 46162]]

populations have reached carrying capacity (Monnahan et al., 2014), (2) 
examples of documented presence and site fidelity of species and long-
term residence by individual animals of some species (Hooker et al., 
2002; McSweeney et al., 2007; McSweeney et al., 2009; McSweeney et al., 
2010; Martin and Kok, 2011; Baumann-Pickering et al., 2012; Falcone and 
Schorr, 2014), (3) use of training and testing areas for breeding and 
nursing activities (Littnan, 2010), and (4) eight years of 
comprehensive monitoring data indicating a lack of any observable 
effects to marine mammal populations as a result of Navy training and 
testing activities.
    To summarize, while the evidence covers most marine mammal 
taxonomic suborders, it is limited to a few species and only suggestive 
of the general viability of those species in intensively used Navy 
training and testing areas (Barlow et al., 2011; Calambokidis et al., 
2009b; Falcone et al., 2009; Littnan, 2011; Martin and Kok, 2011; 
McCarthy et al., 2011; McSweeney et al., 2007; McSweeney et al., 2009; 
Moore and Barlow, 2011; Tyack et al., 2011; Southall et al., 2012a; 
Melcon, 2012; Goldbogen, 2013; Baird et al., 2013). However, there is 
no direct evidence that routine Navy training and testing spanning 
decades has negatively impacted marine mammal populations at any Navy 
range complex. Although there have been a few strandings associated 
with use of sonar in other locations (see U.S. Department of the Navy, 
2013b), Ketten (2012) has recently summarized, ``to date, there has 
been no demonstrable evidence of acute, traumatic, disruptive, or 
profound auditory damage in any marine mammal as the result of 
anthropogenic noise exposures, including sonar.'' Therefore, based on 
the best available science (McSweeney et al., 2007; Falcone et al., 
2009; McSweeney et al., 2009; Littnan, 2010; Barlow et al., 2011; 
Martin and Kok, 2011; McCarthy et al., 2011; Moore and Barlow, 2011; 
Tyack et al., 2011; Southall et al., 2012a; Manzano-Roth et al., 2013; 
DeRuiter et al., 2013; Goldbogen et al., 2013; Moretti et al., 2014; 
Smultea and Jefferson, 2014), including data developed in the series of 
reports submitted to NMFS, we believe that long-term consequences for 
individuals or populations are unlikely to result from Navy training 
and testing activities in the Study Area.

Final Determination

    NMFS concludes that training and testing activities proposed in the 
MITT Study Area could result in Level B and Level A takes, as 
summarized in Table 11. Based on best available science NMFS concludes 
that exposures to marine mammal species due to MITT activities would 
result in primarily short-term (temporary and short in duration) and 
relatively infrequent effects to most individuals, and not of the type 
or severity that would be expected to be additive for the portion of 
the stocks and species likely to be exposed. Marine mammal takes from 
Navy activities are not expected to impact annual rates of recruitment 
or survival and will therefore not result in population-level impacts 
for the following reasons:
     Most acoustic harassments (greater than 99 percent) are 
within the non-injurious TTS or behavioral effects zones (Level B 
harassment consisting of generally temporary modifications in behavior) 
and none of the estimated exposures result in mortality.
     As mentioned earlier, an animal's exposure to a higher 
received level is more likely to result in a behavioral response that 
is more likely to adversely affect the health of the animal. For low 
frequency cetaceans (mysticetes) in the Study Area, most Level B 
exposures will occur at received levels less than 156 dB (Table 22). 
The majority of estimated odontocete takes from MFAS/HFAS (at least for 
hull-mounted sonar, which is responsible for most of the sonar-related 
takes) also result from exposures to received levels less than 156 dB 
(Table 22). Therefore, the majority of Level B takes are expected to be 
in the form of milder responses (i.e., lower-level exposures that still 
rise to the level of a take, but would likely be less severe in the 
range of responses that qualify as a take) and are not expected to have 
deleterious impacts on the fitness of any individuals.
     Acoustic disturbances caused by Navy sonar and explosives 
are short-term, intermittent, and (in the case of sonar) transitory, 
even during major training exercises. Navy activities are generally 
unit level. Unit level events occur over a small spatial scale (one to 
a few 10s of square miles) and with few participants (usually one or 
two). Single-unit unit level training would typically involve a few 
hours of sonar use, with a typical nominal ping of every 50 seconds 
(duty cycle). Even though an animal's exposure to active sonar may be 
more than one time, the intermittent nature of the sonar signal, its 
low duty cycle, and the fact that both the vessel and animal are moving 
provide a very small chance that exposure to active sonar for 
individual animals and stocks would be repeated over extended periods 
of time. Consequently, we would not expect the Navy's activities to 
create conditions of long-term, continuous underwater noise leading to 
habitat abandonment or long-term hormonal or physiological stress 
responses in marine mammals.
     Years of monitoring of Navy activities (since 2006) have 
documented hundreds of thousands of marine mammals on the range 
complexes and there are only two instances of overt behavioral change 
that have been observed.
     Years of monitoring of Navy activities have documented no 
instances of injury to marine mammals as a direct result of non-impulse 
acoustic sources.
     In at least three decades of similar activities, only one 
instance of injury to marine mammals (March 2011; three long-beaked 
common dolphin off Southern California) has been documented as a result 
of training or testing using an impulse source (underwater explosion).
     Range complexes where intensive training and testing have 
been occurring for decades have populations of multiple species with 
strong site fidelity (including highly sensitive resident beaked whales 
at some locations) and increases in the number of some species. 
Populations of beaked whales and other odontocetes in the Bahamas, and 
other Navy fixed ranges that have been operating for tens of years, 
appear to be stable.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, which includes 
consideration of the materials provided in the Navy's LOA application 
and MITT FEIS/OEIS, and dependent upon the implementation of the 
mitigation and monitoring measures, NMFS finds that the total marine 
mammal take from the Navy's training and testing activities in the MITT 
Study Area will have a negligible impact on the affected marine mammal 
species or stocks. NMFS has issued regulations for these activities 
that prescribe the means of effecting the least practicable adverse 
impact on marine mammal species or stocks and their habitat and set 
forth requirements pertaining to the monitoring and reporting of that 
taking.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

    NMFS has determined that the issuance of regulations and subsequent 
LOA for Navy training and testing activities in the MITT Study Area 
would not have an unmitigable adverse impact on the availability of 
species or stocks for subsistence use, since there are no such uses in 
the specified area.

[[Page 46163]]

Endangered Species Act (ESA)

    There are five marine mammal species under NMFS' jurisdiction that 
are listed as endangered or threatened under the ESA with confirmed or 
possible occurrence in the Study Area: Blue whale, humpback whale, fin 
whale, sei whale, and sperm whale. The Navy consulted with NMFS 
pursuant to section 7 of the ESA, and NMFS also consulted internally on 
the issuance of an LOA under section 101(a)(5)(A) of the MMPA for MITT 
activities. NMFS issued a Biological Opinion concluding that the 
issuance of the rule and subsequent LOA are likely to adversely affect, 
but are not likely to jeopardize, the continued existence of the 
threatened and endangered species (and species proposed for listing) 
under NMFS' jurisdiction and are not likely to result in the 
destruction or adverse modification of critical habitat in the MITT 
Study Area. The Biological Opinion for this action is available on 
NMFS' Web site (http://www.nmfs.noaa.gov/pr/permits/incidental/).

National Environmental Policy Act (NEPA)

    NMFS participated as a cooperating agency on the MITT FEIS/OEIS, 
which was published on May 22, 2015 and is available on the Navy's Web 
site: http://www.mitt-eis.com. NMFS determined that the MITT FEIS/OEIS 
is adequate and appropriate to meet our responsibilities under NEPA for 
the issuance of regulations and LOA and adopted the Navy's MITT FEIS/
OEIS.

Classification

    The Office of Management and Budget has determined that this rule 
is not significant for purposes of Executive Order 12866.
    Pursuant to the Regulatory Flexibility Act (RFA), the Chief Counsel 
for Regulation of the Department of Commerce has certified to the Chief 
Counsel for Advocacy of the Small Business Administration that this 
rule, if adopted, would not have a significant economic impact on a 
substantial number of small entities. The RFA requires federal agencies 
to prepare an analysis of a rule's impact on small entities whenever 
the agency is required to publish a notice of proposed rulemaking. 
However, a federal agency may certify, pursuant to 5 U.S.C. 605(b), 
that the action will not have a significant economic impact on a 
substantial number of small entities. The Navy is the sole entity that 
would be affected by this rulemaking, and the Navy is not a small 
governmental jurisdiction, small organization, or small business, as 
defined by the RFA. Any requirements imposed by an LOA issued pursuant 
to these regulations, and any monitoring or reporting requirements 
imposed by these regulations, would be applicable only to the Navy. 
NMFS does not expect the issuance of these regulations or the 
associated LOA to result in any impacts to small entities pursuant to 
the RFA. Because this action, if adopted, would directly affect the 
Navy and not a small entity, NMFS concludes the action would not result 
in a significant economic impact on a substantial number of small 
entities.
    The Assistant Administrator for Fisheries has determined that there 
is good cause under the Administrative Procedure Act (5 U.S.C 
553(d)(3)) to waive the 30-day delay in the effective date of the 
measures contained in the final rule. The Navy is the only entity 
subject to the regulations, and it has informed NMFS that it requests 
that this final rule take effect by August 3, 2015, when the 
regulations issued by NMFS to govern the unintentional taking of marine 
mammals incidental to the Navy's activities in the MIRC study area from 
2010 to 2015 expire. Any delay of enacting the final rule would result 
in either: (1) A suspension of planned naval training, which would 
disrupt vital training essential to national security; or (2) the 
Navy's procedural non-compliance with the MMPA (should the Navy conduct 
training without an LOA), thereby resulting in the potential for 
unauthorized takes of marine mammals. Moreover, the Navy is ready to 
implement the rule immediately. For these reasons, the Assistant 
Administrator finds good cause to waive the 30-day delay in the 
effective date.

List of Subjects in 50 CFR Part 218

    Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine 
mammals, Navy, Penalties, Reporting and recordkeeping requirements, 
Seafood, Sonar, Transportation.

    Dated: July 24, 2015.
Paul N. Doremus,
Deputy Assistant Administrator for Operations, National Marine 
Fisheries Service.

    For reasons set forth in the preamble, 50 CFR part 218 is amended 
as follows:

PART 218--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE 
MAMMALS

0
1. The authority citation for part 218 continues to read as follow:

    Authority: 16 U.S.C. 1361 et seq.


0
2. Subpart J is added to part 218 to read as follows:
Subpart J--Taking and Importing Marine Mammals; U.S. Navy's Mariana 
Islands Training and Testing (MITT)
Sec.
218.90 Specified activity and specified geographical region.
218.91 Effective dates and definitions.
218.92 Permissible methods of taking.
218.93 Prohibitions.
218.94 Mitigation.
218.95 Requirements for monitoring and reporting.
218.96 Applications for Letters of Authorization.
218.97 Letter of Authorization.
218.98 Renewal and modifications of Letters of Authorization.

Subpart J--Taking and Importing Marine Mammals; U.S. Navy's Mariana 
Islands Training and Testing (MITT)


Sec.  218.90  Specified activity and specified geographical region.

    (a) Regulations in this subpart apply only to the U.S. Navy for the 
taking of marine mammals that occurs in the area outlined in paragraph 
(b) of this section and that occurs incidental to the activities 
described in paragraph (c) of this section.
    (b) The taking of marine mammals by the Navy is only authorized if 
it occurs within the MITT Study Area, which includes the Mariana 
Islands Range Complex (MIRC) and areas to the north and west. The Study 
Area includes established ranges, operating areas, warning areas, and 
special use airspace in the region of the Mariana Islands that are part 
of the MIRC, its surrounding seas, and a transit corridor to the Hawaii 
Range Complex. The Study Area also includes Navy pierside locations 
where sonar maintenance and testing may occur.
    (c) The taking of marine mammals by the Navy is only authorized if 
it occurs incidental to the following activities within the designated 
amounts of use:
    (1) Non-impulsive Sources Used During Training and Testing:
    (i) Low-frequency (LF) Source Classes:
    (A) LF4--an average of 123 hours per year.
    (B) LF5--an average of 11 hours per year.
    (C) LF6--an average of 40 hours per year.
    (ii) Mid-frequency (MF) Source Classes:
    (A) MF1--an average of 1,872 hours per year.
    (B) MF2--an average of 625 hours per year.
    (C) MF3--an average of 192 hours per year.

[[Page 46164]]

    (D) MF4--an average of 214 hours per year.
    (E) MF5--an average of 2,588 items per year.
    (F) MF6--an average of 33 items per year.
    (G) MF8--an average of 123 hours per year.
    (H) MF9--an average of 47 hours per year.
    (I) MF10--an average of 231 hours per year.
    (J) MF11--an average of 324 hours per year.
    (K) MF12--an average of 656 hours per year.
    (iii) High-frequency (HF) and Very High-frequency (VHF) Source 
Classes:
    (A) HF1--an average of 113 hours per year.
    (B) HF4--an average of 1,060 hours per year.
    (C) HF5--an average of 336 hours per year.
    (D) HF6--an average of 1,173 hours per year.
    (iv) Anti-Submarine Warfare (ASW) Source Classes:
    (A) ASW1--an average of 144 hours per year.
    (B) ASW2--an average of 660 items per year.
    (C) ASW3--an average of 3,935 hours per year.
    (D) ASW4--an average of 32 items per year.
    (v) Torpedoes (TORP) Source Classes:
    (A) TORP1--an average of 115 items per year.
    (B) TORP2--an average of 62 items per year.
    (vi) Acoustic Modems (M):
    (A) M3--an average of 112 hours per year.
    (B) [Reserved]
    (vii) Swimmer Detection Sonar (SD):
    (A) SD1--an average 2,341 hours per year.
    (B) [Reserved]
    (2) Impulsive Source Detonations During Training and Testing:
    (i) Explosive Classes:
    (A) E1 (0.1 to 0.25 lb NEW)--an average of 10,140 detonations per 
year.
    (B) E2 (0.26 to 0.5 lb NEW)--an average of 106 detonations per 
year.
    (C) E3 (>0.5 to 2.5 lb NEW)--an average of 932 detonations per 
year.
    (D) E4 (>2.5 to 5 lb NEW)--an average of 420 detonations per year.
    (E) E5 (>5 to 10 lb NEW)--an average of 684 detonations per year.
    (F) E6 (>10 to 20 lb NEW)--an average of 76 detonations per year.
    (G) E8 (>60 to 100 lb NEW)--an average of 16 detonations per year.
    (H) E9 (>100 to 250 lb NEW)--an average of 4 detonations per year.
    (I) E10 (>250 to 500 lb NEW)--an average of 12 detonations per 
year.
    (J) E11 (>500 to 650 lb NEW)--an average of 6 detonations per year.
    (K) E12 (>650 to 2,000 lb NEW)--an average of 184 detonations per 
year.
    (ii) [Reserved]


Sec.  218.91  Effective dates and definitions.

    (a) Regulations in this subpart are effective August 3, 2015 
through August 3, 2020.
    (b) The following definitions are utilized in these regulations:
    (1) Uncommon Stranding Event (USE)--A stranding event that takes 
place within an OPAREA where a Major Training Exercise (MTE) occurs and 
involves any one of the following:
    (i) Two or more individuals of any cetacean species (not including 
mother/calf pairs, unless of species of concern listed in paragraph 
(b)(1)(ii) of this section) found dead or live on shore within a 2-day 
period and occurring within 30 miles of one another.
    (ii) A single individual or mother/calf pair of any of the 
following marine mammal species of concern: Beaked whale of any 
species, Kogia spp., Risso's dolphin, melon-headed whale, pilot whale, 
humpback whale, sperm whale, blue whale, fin whale, or sei whale.
    (iii) A group of two or more cetaceans of any species exhibiting 
indicators of distress.
    (2) Shutdown--The cessation of active sonar operation or detonation 
of explosives within 14 nautical miles of any live, in the water, 
animal involved in a USE.


Sec.  218.92  Permissible methods of taking.

    (a) Under a Letter of Authorization (LOA) issued pursuant to Sec.  
218.97, the Holder of the Letter of Authorization may incidentally, but 
not intentionally, take marine mammals within the area described in 
Sec.  218.90, provided the activity is in compliance with all terms, 
conditions, and requirements of these regulations and the appropriate 
LOA.
    (b) The activities identified in Sec.  218.90(c) must be conducted 
in a manner that minimizes, to the greatest extent practicable, any 
adverse impacts on marine mammals and their habitat.
    (c) The incidental take of marine mammals under the activities 
identified in Sec.  218.90(c) is limited to the following species, by 
the identified method of take:
    (1) Level B Harassment for all Training and Testing Activities:
    (i) Mysticetes:
    (A) Blue whale (Balaenoptera musculus)--140 (an average of 28 
annually)
    (B) Bryde's whale (Balaenoptera edeni)--1,990 (an average of 398 
annually)
    (C) Fin whale (Balaenoptera physalus)--140 (an average of 28 
annually)
    (D) Humpback whale (Megaptera novaeangliae)--4,300 (an average of 
860 annually)
    (E) Minke whale (Balaenoptera acutorostrata)--505 (an average of 
101 annually)
    (F) Sei whale (Balaenoptera borealis)--1,595 (an average of 319 
annually)
    (G) Omura's whale (Balaenoptera omurai)--515 (an average of 103 
annually)
    (ii) Odontocetes:
    (A) Blainville's beaked whale (Mesoplodon densirostris)--22,130 (an 
average of 4,426 annually)
    (B) Bottlenose dolphin (Tursiops truncatus)--3,705 (an average of 
741 annually)
    (C) Cuvier's beaked whale (Ziphius cavirostris)--112,705 (an 
average of 22,541 annually)
    (D) Dwarf sperm whale (Kogia sima)--71,085 (an average of 14,217 
annually)
    (E) False killer whale (Pseudorca crassidens)--2,775 (an average of 
555 annually)
    (F) Fraser's dolphin (Lagenodelphis hosei)--12,860 (an average of 
2,572 annually)
    (G) Gingko-toothed beaked whale (Mesoplodon ginkgodens)--19,485 (an 
average of 3,897 annually)
    (H) Killer whale (Orcinus orca)--420 (an average of 84 annually)
    (I) Longman's beaked whale (Indopacetus pacificus)--9,620 (an 
average of 1,924 annually)
    (J) Melon-headed whale (Peponocephala electra)--10,425 (an average 
of 2,085 annually)
    (K) Pantropical spotted dolphin (Stenella attenuata)--64,055 (an 
average of 12,811 annually)
    (L) Pygmy killer whale (Feresa attenuata)--525 (an average of 105 
annually)
    (M) Pygmy sperm whale (Kogia breviceps)--27,895 (an average of 
5,579 annually)
    (N) Risso's dolphin (Grampus griseus)--2,525 (an average of 505 
annually)
    (O) Rough-toothed dolphin (Steno bredanensis)--9,095 (an average of 
1,819 annually)
    (P) Short-finned pilot whale (Globicephala macrorhynchus)--9,075 
(an average of 1,815 annually)
    (Q) Sperm whale (Physeter macrocephalus)--2,530 (an average of 506 
annually)
    (R) Spinner dolphin (Stenella longirostris)--2,945 (an average of 
589 annually)

[[Page 46165]]

    (S) Striped dolphin (Stenella coerulealba)--16,490 (an average of 
3,298 annually)
    (2) Level A Harassment for all Training and Testing Activities:
    (i) Odontocetes:
    (A) Dwarf sperm whale (Kogia sima)--205 (an average of 41 annually)
    (B) Pygmy sperm whale (Kogia breviceps)--75 (an average of 15 
annually)
    (ii) [Reserved]


Sec.  218.93  Prohibitions.

    Notwithstanding takings contemplated in Sec.  218.92 and authorized 
by an LOA issued under Sec. Sec.  216.106 and 218.97 of this chapter, 
no person in connection with the activities described in Sec.  218.90 
may:
    (a) Take any marine mammal not specified in Sec.  218.92(c);
    (b) Take any marine mammal specified in Sec.  218.92(c) other than 
by incidental take as specified in Sec.  218.92(c);
    (c) Take a marine mammal specified in Sec.  218.92(c) if such 
taking results in more than a negligible impact on the species or 
stocks of such marine mammal; or
    (d) Violate, or fail to comply with, the terms, conditions, and 
requirements of these regulations or an LOA issued under Sec. Sec.  
216.106 and 218.97.


Sec.  218.94  Mitigation.

    (a) When conducting training and testing activities, as identified 
in Sec.  218.90, the mitigation measures contained in the LOA issued 
under Sec. Sec.  216.106 and 218.97 of this chapter must be 
implemented. These mitigation measures include, but are not limited to:
    (1) Lookouts. The following are protective measures concerning the 
use of lookouts.
    (i) Lookouts positioned on surface ships will be dedicated solely 
to diligent observation of the air and surface of the water. Their 
observation objectives will include, but are not limited to, detecting 
the presence of biological resources and recreational or fishing boats, 
observing mitigation zones, and monitoring for vessel and personnel 
safety concerns.
    (ii) Lookouts positioned in aircraft or on boats will, to the 
maximum extent practicable and consistent with aircraft and boat safety 
and training and testing requirements, comply with the observation 
objectives described in paragraph (a)(1)(i) of this section.
    (iii) Lookout measures for non-impulse sound:
    (A) With the exception of vessels less than 65 ft (20 m) in length 
and ships that are minimally manned, ships using low-frequency or hull-
mounted mid-frequency active sonar sources associated with anti-
submarine warfare and mine warfare activities at sea will have two 
lookouts at the forward position. For the purposes of this rule, low-
frequency active sonar does not include surface towed array 
surveillance system low-frequency active sonar.
    (B) While using low-frequency or hull-mounted mid-frequency active 
sonar sources associated with anti-submarine warfare and mine warfare 
activities at sea, ships less than 65 ft (20 m) in length and ships 
that are minimally manned will have one lookout at the forward position 
of the vessel due to space and manning restrictions.
    (C) Ships conducting active sonar activities while moored or at 
anchor (including pierside testing or maintenance) will maintain one 
lookout.
    (D) Surface ships or aircraft conducting high-frequency or non-hull 
mounted mid-frequency active sonar activities associated with anti-
submarine warfare and mine warfare activities at sea will have one 
lookout.
    (iv) Lookout measures for explosives and impulse sound:
    (A) Aircraft conducting IEER sonobuoy activities and explosive 
sonobuoy exercises will have one lookout.
    (B) Surface vessels conducting anti-swimmer grenade activities will 
have one lookout.
    (C) During general mine countermeasure and neutralization 
activities using up to a 20-lb net explosive weight detonation (bin E6 
and below), vessels greater than 200 ft (61 m) will have two lookouts, 
while vessels less than 200 ft (61 m) or aircraft will have one 
lookout.
    (D) Mine neutralization activities involving positive control 
diver-placed charges using up to a 20-lb net explosive weight 
detonation will have two lookouts. The divers placing the charges on 
mines will report all marine mammal sightings to their supporting small 
boat or Range Safety Officer.
    (E) When mine neutralization activities using diver-placed charges 
with up to a 20-lb net explosive weight detonation are conducted with a 
time-delay firing device, four lookouts will be used. Two lookouts will 
be positioned in each of two small rigid hull inflatable boats. When 
aircraft are used, the pilot or member of the aircrew will serve as an 
additional lookout. The divers placing the charges on mines will report 
all marine mammal sightings to their supporting small boat or Range 
Safety Officer.
    (F) Surface vessels or aircraft conducting small- or medium-caliber 
gunnery exercises against a surface target will have one lookout.
    (G) Aircraft conducting missile exercises (including rockets) 
against surface targets will have one lookout.
    (H) Aircraft conducting bombing exercises will have one lookout.
    (I) During explosive torpedo testing, one lookout will be used and 
positioned in an aircraft.
    (J) During sinking exercises, two lookouts will be used. One 
lookout will be positioned in an aircraft and one on a surface vessel.
    (K) Surface vessels conducting explosive and non-explosive large-
caliber gunnery exercises will have one lookout.
    (v) Lookout measures for physical strike and disturbance:
    (A) While underway, surface ships will have at least one lookout.
    (B) During activities using towed in-water devices, that are towed 
from a manned platform, one lookout will be used.
    (C) Non-explosive small-, medium-, and large-caliber gunnery 
exercises using a surface target will have one lookout.
    (D) Non-explosive bombing exercises will have one lookout.
    (2) Mitigation zones. The following are protective measures 
concerning the implementation of mitigation zones.
    (i) Mitigation zones will be measured as the radius from a source 
and represent a distance to be monitored.
    (ii) Visual detections of marine mammals within a mitigation zone 
will be communicated immediately to a watch station for information 
dissemination and appropriate action.
    (iii) Mitigation zones for non-impulse sound:
    (A) When marine mammals are visually detected, the Navy shall 
ensure that low-frequency and hull-mounted mid-frequency active sonar 
transmission levels are limited to at least 6 dB below normal operating 
levels (for sources that can be powered down during the activity) if 
any visually detected marine mammals are within 1,000 yd (914 m) of the 
source (i.e., the bow).
    (B) The Navy shall ensure that low-frequency and hull-mounted mid-
frequency active sonar transmissions are limited to at least 10 dB 
below the equipment's normal operating level (for sources that can be 
powered down during the activity) if any detected marine mammals are 
sighted within 500 yd (457 m) of the source.
    (C) The Navy shall ensure that low-frequency and hull-mounted mid-
frequency active sonar transmissions

[[Page 46166]]

(for sources that can be turned off during the activity) are ceased if 
any visually detected marine mammals are within 200 yd (183 m) of the 
sonar dome. Active transmission will recommence if any one of the 
following conditions is met: The animal is observed exiting the 
mitigation zone; the animal is thought to have exited the mitigation 
zone based on a determination of its course and speed and the relative 
motion between the animal and the source; the mitigation zone has been 
clear from any additional sightings for a period of 30 minutes; the 
ship has transited more than 2,000 yd. (1.8 kilometers [km]) beyond the 
location of the last sighting; or the ship concludes that dolphins are 
deliberately closing in on the ship to ride the ship's bow wave (and 
there are no other marine mammal sightings within the mitigation zone).
    (D) If the source is not able to be powered down during the 
activity (e.g., low-frequency sources within bins LF4 and LF5), 
mitigation will involve ceasing active transmission if a marine mammal 
is sighted within 200 yd. (183 m). Active transmission will recommence 
if any one of the following conditions is met: The animal is observed 
exiting the mitigation zone; the animal is thought to have exited the 
mitigation zone based on a determination of its course and speed and 
the relative motion between the animal and the source; the mitigation 
zone has been clear from any additional sightings for a period of 30 
minutes; or the ship has transited more than 400 yd. (366 m) beyond the 
location of the last sighting.
    (E) With the exception of activities involving platforms operating 
at high altitudes, when marine mammals are visually detected, the Navy 
shall ensure that high-frequency and non-hull-mounted mid-frequency 
active sonar transmission (for sources that can be turned off during 
the activity) is ceased if any visually detected marine mammals are 
within 200 yd (183 m) of the source. Active transmission will 
recommence if any one of the following conditions is met: The animal is 
observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on a determination of its course and 
speed and the relative motion between the animal and the source, the 
mitigation zone has been clear from any additional sightings for a 
period of 10 minutes for an aircraft-deployed source, the mitigation 
zone has been clear from any additional sightings for a period of 30 
minutes for a vessel-deployed source, the vessel or aircraft has 
repositioned itself more than 400 yd. (366 m) away from the location of 
the last sighting, or the vessel concludes that dolphins are 
deliberately closing in to ride the vessel's bow wave (and there are no 
other marine mammal sightings within the mitigation zone).
    (F) Prior to start up or restart of active sonar, operators shall 
check that the mitigation zone radius around the sound source is clear 
of marine mammals.
    (G) Generally, the Navy shall operate sonar at the lowest 
practicable level, not to exceed 235 dB, except as required to meet 
tactical training objectives.
    (iv) Mitigation zones for explosive and impulse sound:
    (A)(1) A mitigation zone with a radius of 600 yd (549 m) shall be 
established for IEER sonobuoys (bin E4). Mitigation would include pre-
exercise aerial observation and passive acoustic monitoring, which 
would begin 30 minutes before the first source/receiver pair detonation 
and continue throughout the duration of the exercise. The pre-exercise 
aerial observation would include the time it takes to deploy the 
sonobuoy pattern (deployment is conducted by aircraft dropping 
sonobuoys in the water). Explosive detonations would cease if a marine 
mammal is sighted within the mitigation zone. Detonations would 
recommence if any one of the following conditions is met: The animal is 
observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on its course and speed and the 
relative motion between the animal and the source, or the mitigation 
zone has been clear from any additional sightings for a period of 30 
minutes.
    (2) Passive acoustic monitoring would be conducted with Navy 
assets, such as sonobuoys, already participating in the activity. These 
assets would only detect vocalizing marine mammals within the frequency 
bands monitored by Navy personnel. Passive acoustic detections would 
not provide range or bearing to detected animals, and therefore cannot 
provide locations of these animals. Passive acoustic detections would 
be reported to lookouts posted in aircraft and on vessels in order to 
increase vigilance of their visual observation.
    (B)(1) A mitigation zone with a radius of 350 yd (320 m) shall be 
established for explosive sonobuoys using 0.5-2.5 lb net explosive 
weight (bin E3). Mitigation would include pre-exercise aerial 
monitoring during deployment of the field of sonobuoy pairs (typically 
up to 20 minutes) and continuing throughout the duration of the 
exercise within a mitigation zone of 350 yd (320 m) around an explosive 
sonobuoy. Explosive detonations would cease if a marine mammal is 
sighted within the mitigation zone. Detonations would recommence if any 
one of the following conditions is met: The animal is observed exiting 
the mitigation zone, the animal is thought to have exited the 
mitigation zone based on its course and speed and the relative motion 
between the animal and the source, or the mitigation zone has been 
clear from any additional sightings for a period of 10 minutes.
    (2) Passive acoustic monitoring would also be conducted with Navy 
assets, such as sonobuoys, already participating in the activity. These 
assets would only detect vocalizing marine mammals within the frequency 
bands monitored by Navy personnel. Passive acoustic detections would 
not provide range or bearing to detected animals, and therefore cannot 
provide locations of these animals. Passive acoustic detections would 
be reported to lookouts posted in aircraft in order to increase 
vigilance of their visual observation.
    (C) A mitigation zone with a radius of 200 yd (183 m) shall be 
established for anti-swimmer grenades (bin E2). Mitigation would 
include visual observation from a small boat immediately before and 
during the exercise within a mitigation zone of 200 yd (183 m) around 
an anti-swimmer grenade. Explosive detonations would cease if a marine 
mammal is sighted within the mitigation zone. Detonations would 
recommence if any one of the following conditions is met: The animal is 
observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on its course and speed and the 
relative motion between the animal and the source, the mitigation zone 
has been clear from any additional sightings for a period of 30 
minutes, or the activity has been repositioned more than 400 yd (366 m) 
away from the location of the last sighting.
    (D) A mitigation zone ranging from 350 yd (320 m) to 800 yd (732 
m), dependent on charge size and if the activity involves the use of 
diver-placed charges, shall be established for mine countermeasure and 
neutralization activities using positive control firing devices. 
Mitigation zone distances are specified for charge size in the 
following table.

[[Page 46167]]



------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               General mine countermeasure and neutralization activities using    Mine countermeasure and neutralization activities using diver
                                                                             positive control firing devices \1\                            placed charges under positive control \2\
                                                             -----------------------------------------------------------------------------------------------------------------------------------
          Charge size net  explosive weight  (bins)              Predicted       Predicted       Predicted                         Predicted       Predicted       Predicted
                                                               average range   average range   maximum range     Recommended     average range   average range   maximum range     Recommended
                                                                  to TTS          to PTS          to PTS       mitigation zone      to TTS          to PTS          to PTS       mitigation zone
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2.5-5 lb. (1.2-2.3 kg) (E4).................................          434 yd          197 yd          563 yd            600 yd          545 yd          169 yd          301 yd           350 yd.
                                                                     (474 m)         (180 m)         (515 m)           (549 m)         (498 m)         (155 m)         (275 m)          (320 m).
5-10 lb. (2.7-4.5 kg) (E5)..................................          525 yd          204 yd          649 yd            800 yd          587 yd          203 yd          464 yd           500 yd.
                                                                     (480 m)         (187 m)         (593 m)           (732 m)         (537 m)         (185 m)         (424 m)          (457 m).
>10-20 lb. (5-9.1 kg) (E6)..................................          766 yd          288 yd          648 yd            800 yd          647 yd          232 yd          469 yd           500 yd.
                                                                     (700 m)         (263 m)         (593 m)           (732 m)         (592 m)         (212 m)         (429 m)          (457 m).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PTS: permanent threshold shift; TTS: temporary threshold shift.
\1\ These mitigation zones are applicable to all mine countermeasure and neutralization activities conducted in all locations specified in Chapter 2 of the Navy's LOA application.
\2\ These mitigation zones are only applicable to mine countermeasure and neutralization activities involving the use of diver placed charges. These activities are conducted in shallow-water
  and the mitigation zones are based only on the functional hearing groups with species that occur in these areas (mid-frequency cetaceans and sea turtles).

    (1) During general mine countermeasure and neutralization 
activities, mitigation would include visual observation from one or 
more small boats or aircraft beginning 30 minutes before, during, and 
30 minutes after (when helicopters are not involved in the activity) or 
10 minutes before, during, and 10 minutes after (when helicopters are 
involved in the activity) the completion of the exercise within the 
mitigation zones around the detonation site.
    (2) For activities involving diver-placed charges, visual 
observation would be conducted by either two small boats, or one small 
boat in combination with one helicopter. Boats would position 
themselves near the mid-point of the mitigation zone radius (but always 
outside the detonation plume radius and human safety zone) and travel 
in a circular pattern around the detonation location. When using two 
boats, each boat would be positioned on opposite sides of the 
detonation location, separated by 180 degrees. If used, helicopters 
would travel in a circular pattern around the detonation location.
    (3) For both general and diver-placed positive control mine 
countermeasure and neutralization activities, explosive detonations 
will cease if a marine mammal is sighted within the mitigation zone. 
Detonations will recommence if any one of the following conditions is 
met: The animal is observed exiting the mitigation zone, the animal is 
thought to have exited the mitigation zone based on a determination of 
its course and speed and the relative motion between the animal and the 
source, the mitigation zone has been clear from any additional 
sightings for a period of 30 minutes, when helicopters are not involved 
in the activity or the mitigation zone has been clear from any 
additional sightings for a period of 10 minutes when helicopters are 
involved in the activity.
    (E) A mitigation zone with a radius of 1,000 yd (914 m) shall be 
established for mine countermeasure and neutralization activities using 
diver-placed time-delay firing devices (bin E6). Mine neutralization 
activities involving diver-placed charges would not include time-delay 
longer than 10 minutes. Mitigation would include visual observation 
from small boats or aircraft commencing 30 minutes before, during, and 
until 30 minutes after the completion of the exercise within a 
mitigation zone of 1,000 yd (914 m) around the detonation site. During 
activities using time-delay firing devices involving up to a 20 lb net 
explosive weight charge, visual observation will take place using two 
small boats. Fuse initiation would recommence if any one of the 
following conditions is met: The animal is observed exiting the 
mitigation zone, the animal is thought to have exited the mitigation 
zone based on its course and speed and the relative motion between the 
animal and the source, or the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes.
    (1) Survey boats would position themselves near the mid-point of 
the mitigation zone radius (but always outside the detonation plume 
radius/human safety zone) and travel in a circular pattern around the 
detonation location. One lookout from each boat would look inward 
toward the detonation site and the other lookout would look outward 
away from the detonation site. When using two small boats, each boat 
would be positioned on opposite sides of the detonation location, 
separated by 180 degrees. If available for use, helicopters would 
travel in a circular pattern around the detonation location.
    (2) [Reserved]
    (F) A mitigation zone with a radius of 200 yd (183 m) shall be 
established for small- and medium-caliber gunnery exercises with a 
surface target (bin E2). Mitigation would include visual observation 
from a vessel or aircraft immediately before and during the exercise 
within a mitigation zone of 200 yd (183 m) around the intended impact 
location. Vessels would observe the mitigation zone from the firing 
position. When aircraft are firing, the aircrew would maintain visual 
watch of the mitigation zone during the activity. Firing would cease if 
a marine mammal is sighted within the mitigation zone. Firing would 
recommence if any one of the following conditions is met: The animal is 
observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on its course and speed and the 
relative motion between the animal and the source, the mitigation zone 
has been clear from any additional sightings for a period of 10 minutes 
for a firing aircraft, the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes for a firing vessel, or 
the intended target location has been repositioned more than 400 yd 
(366 m) away from the location of the last sighting.
    (G) A mitigation zone with a radius of 600 yd (549 m) shall be 
established for large-caliber gunnery exercises with a surface target 
(bin E5). Mitigation would include visual observation from a ship 
immediately before and during the exercise within a mitigation zone of 
600 yd (549 m) around the intended impact location. Ships would observe 
the mitigation zone from the firing position. Firing would cease if a 
marine mammal is sighted within the mitigation zone. Firing would 
recommence if any one of the following conditions is met: The animal is 
observed exiting the mitigation zone, the animal is thought to

[[Page 46168]]

have exited the mitigation zone based on its course and speed and the 
relative motion between the animal and the source, or the mitigation 
zone has been clear from any additional sightings for a period of 30 
minutes.
    (H) A mitigation zone with a radius of 900 yd (823 m) around the 
deployed target shall be established for missile exercises involving 
aircraft firing up to 250 lb net explosive weight using and a surface 
target (bin E9). When aircraft are firing, mitigation would include 
visual observation by the aircrew or supporting aircraft prior to 
commencement of the activity within a mitigation zone of 900 yd (823 m) 
around the deployed target. Firing would recommence if any one of the 
following conditions is met: The animal is observed exiting the 
mitigation zone, the animal is thought to have exited the mitigation 
zone based on its course and speed and the relative motion between the 
animal and the source, or the mitigation zone has been clear from any 
additional sightings for a period of 10 minutes or 30 minutes 
(depending on aircraft type).
    (I) A mitigation zone with a radius of 2,000 yd (1.8 km) shall be 
established for missile exercises involving aircraft firing >250 to 500 
lb net explosive weight using and a surface target (bin E10). When 
aircraft are firing, mitigation would include visual observation by the 
aircrew prior to commencement of the activity within a mitigation zone 
of 2,000 yd (1.8 km) around the intended impact location. Firing would 
cease if a marine mammal is sighted within the mitigation zone. Firing 
would recommence if any one of the following conditions is met: The 
animal is observed exiting the mitigation zone, the animal is thought 
to have exited the mitigation zone based on its course and speed and 
the relative motion between the animal and the source, or the 
mitigation zone has been clear from any additional sightings for a 
period of 10 minutes or 30 minutes (depending on aircraft type).
    (J) A mitigation zone with a radius of 2,500 yd (2.3 km) shall be 
established for bombing exercises (bin E12). Mitigation would include 
visual observation from the aircraft immediately before the exercise 
and during target approach within a mitigation zone of 2,500 yd (2.3 
km) around the intended impact location. Bombing would cease if a 
marine mammal is sighted within the mitigation zone. Bombing would 
recommence if any one of the following conditions is met: The animal is 
observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on its course and speed and the 
relative motion between the animal and the source, or the mitigation 
zone has been clear from any additional sightings for a period of 10 
minutes.
    (K)(1) A mitigation zone with a radius of 2,100 yd (1.9 km) shall 
be established for torpedo (explosive) testing (except for aircraft 
operating at high altitudes) (bin E11). Mitigation would include visual 
observation by aircraft immediately before, during, and after the 
exercise within a mitigation zone of 2,100 yd (1.9 km) around the 
intended impact location. Firing would cease if a marine mammal is 
sighted within the mitigation zone. Firing would recommence if any one 
of the following conditions is met: The animal is observed exiting the 
mitigation zone, the animal is thought to have exited the mitigation 
zone based on its course and speed and the relative motion between the 
animal and the source, or the mitigation zone has been clear from any 
additional sightings for a period of 10 minutes or 30 minutes 
(depending on aircraft type).
    (2) In addition to visual observation, passive acoustic monitoring 
would be conducted with Navy assets, such as passive ships sonar 
systems or sonobuoys, already participating in the activity. Passive 
acoustic observation would be accomplished through the use of remote 
acoustic sensors or expendable sonobuoys, or via passive acoustic 
sensors on submarines when they participate in the proposed action. 
These assets would only detect vocalizing marine mammals within the 
frequency bands monitored by Navy personnel. Passive acoustic 
detections would not provide range or bearing to detected animals, and 
therefore cannot provide locations of these animals. Passive acoustic 
detections would be reported to the lookout posted in the aircraft in 
order to increase vigilance of the visual observation and to the person 
in control of the activity for their consideration in determining when 
the mitigation zone is free of visible marine mammals.
    (L) A mitigation zone with a radius of 2.5 nautical miles around 
the target ship hulk shall be established for sinking exercises (bin 
E12). Mitigation would include aerial observation beginning 90 minutes 
before the first firing, visual observations from vessels throughout 
the duration of the exercise, and both aerial and vessel observation 
immediately after any planned or unplanned breaks in weapons firing of 
longer than 2 hours. Prior to conducting the exercise, the Navy would 
review remotely sensed sea surface temperature and sea surface height 
maps to aid in deciding where to release the target ship hulk.
    (1) The Navy would also monitor using passive acoustics during the 
exercise. Passive acoustic monitoring would be conducted with Navy 
assets, such as passive ships sonar systems or sonobuoys, already 
participating in the activity. These assets would only detect 
vocalizing marine mammals within the frequency bands monitored by Navy 
personnel. Passive acoustic detections would not provide range or 
bearing to detected animals, and therefore cannot provide locations of 
these animals. Passive acoustic detections would be reported to 
lookouts posted in aircraft and on vessels in order to increase 
vigilance of their visual observation. Lookouts will also increase 
observation vigilance before the use of torpedoes or unguided ordnance 
with a net explosive weight of 500 lb or greater, or if the Beaufort 
sea state is a 4 or above.
    (2) The exercise would cease if a marine mammal is sighted within 
the mitigation zone. The exercise would recommence if any one of the 
following conditions is met: The animal is observed exiting the 
mitigation zone, the animal is thought to have exited the mitigation 
zone based on its course and speed and the relative motion between the 
animal and the source, or the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes. Upon sinking the 
vessel, the Navy would conduct post-exercise visual observation of the 
mitigation zone for 2 hours (or until sunset, whichever comes first).
    (M) A mitigation zone with a radius of 70 yd (64 m) within 30 
degrees on either side of the gun target line on the firing side of the 
vessel for explosive and non-explosive large-caliber gunnery exercises 
conducted from a ship. Firing would cease if a marine mammal is sighted 
within the mitigation zone. Firing would recommence if any one of the 
following conditions is met: The animal is observed exiting the 
mitigation zone, the animal is thought to have exited the mitigation 
zone based on its course and speed and the relative motion between the 
animal and the source, the mitigation zone has been clear from any 
additional sightings for a period of 30 minutes, or the vessel has 
repositioned itself more than 140 yd (128 m) away from the location of 
the last sighting.
    (v) Mitigation zones for vessels and in-water devices:
    (A) A mitigation zone of 500 yd (457 m) for observed whales and 200 
yd (183 m) for all other marine mammals (except bow riding dolphins) 
shall be

[[Page 46169]]

established for all vessel movement, providing it is safe to do so.
    (B) A mitigation zone of 250 yd (229 m) shall be established for 
all towed in-water devices that are towed from a manned platform, 
providing it is safe to do so.
    (vi) Mitigation zones for non-explosive practice munitions:
    (A) A mitigation zone of 200 yd (183 m) shall be established for 
non-explosive small-, medium-, and large-caliber gunnery exercises 
using a surface target. Mitigation would include visual observation 
immediately before and during the exercise within a mitigation zone of 
200 m around the intended impact location. Firing would cease if a 
marine mammal is visually detected within the mitigation zone. Firing 
would recommence if any one of the following conditions are met: The 
animal is observed exiting the mitigation zone, the animal is thought 
to have exited the mitigation zone based on its course and speed and 
the relative motion between the animal and the source, the mitigation 
zone has been clear from any additional sightings for a period of 10 
minutes for a firing aircraft, the mitigation zone has been clear from 
any additional sightings for a period of 30 minutes for a firing 
vessel, or the intended target location has been repositioned more than 
400 yd (366 m) away from the location of the last sighting and the 
animal's estimated course direction.
    (B) A mitigation zone of 1,000 yd (914 m) shall be established for 
non-explosive bombing exercises. Mitigation would include visual 
observation from the aircraft immediately before the exercise and 
during target approach within a mitigation zone of 1000 yd (914 m) 
around the intended impact location. Bombing would cease if a marine 
mammal is visually detected within the mitigation zone. Bombing would 
recommence if any one of the following conditions are met: The animal 
is observed exiting the mitigation zone, the animal is thought to have 
exited the mitigation zone based on its course and speed and the 
relative motion between the animal and the source, or the mitigation 
zone has been clear from any additional sightings for a period of 10 
minutes.
    (3) Stranding Response Plan:
    (i) The Navy shall abide by the letter of the ``Stranding Response 
Plan for Major Navy Training Exercises in the MITT Study Area,'' to 
include the following measures:
    (A) Shutdown Procedures--When an Uncommon Stranding Event (USE--
defined in Sec.  218.91) occurs during a Major Training Exercise (MTE) 
in the MITT Study Area, the Navy shall implement the procedures 
described below.
    (1) The Navy shall implement a shutdown (as defined Sec.  218.91) 
when advised by a NMFS Office of Protected Resources Headquarters 
Senior Official designated in the MITT Study Area Stranding 
Communication Protocol that a USE involving live animals has been 
identified and that at least one live animal is located in the water. 
NMFS and the Navy will maintain a dialogue, as needed, regarding the 
identification of the USE and the potential need to implement shutdown 
procedures.
    (2) Any shutdown in a given area shall remain in effect in that 
area until NMFS advises the Navy that the subject(s) of the USE at that 
area die or are euthanized, or that all live animals involved in the 
USE at that area have left the area (either of their own volition or 
herded).
    (3) If the Navy finds an injured or dead animal floating at sea 
during an MTE, the Navy shall notify NMFS immediately or as soon as 
operational security considerations allow. The Navy shall provide NMFS 
with species or description of the animal(s), the condition of the 
animal(s), including carcass condition if the animal(s) is/are dead, 
location, time of first discovery, observed behavior (if alive), and 
photo or video (if available). Based on the information provided, NFMS 
will determine if, and advise the Navy whether a modified shutdown is 
appropriate on a case-by-case basis.
    (4) In the event, following a USE, that qualified individuals are 
attempting to herd animals back out to the open ocean and animals are 
not willing to leave, or animals are seen repeatedly heading for the 
open ocean but turning back to shore, NMFS and the Navy shall 
coordinate (including an investigation of other potential anthropogenic 
stressors in the area) to determine if the proximity of mid-frequency 
active sonar training activities or explosive detonations, though 
farther than 14 nautical miles from the distressed animal(s), is likely 
contributing to the animals' refusal to return to the open water. If 
so, NMFS and the Navy will further coordinate to determine what 
measures are necessary to improve the probability that the animals will 
return to open water and implement those measures as appropriate.
    (5) Within 72 hours of NMFS notifying the Navy of the presence of a 
USE, the Navy shall provide available information to NMFS (per the MITT 
Study Area Communication Protocol) regarding the location, number and 
types of acoustic/explosive sources, direction and speed of units using 
mid-frequency active sonar, and marine mammal sightings information 
associated with training activities occurring within 80 nautical miles 
(148 km) and 72 hours prior to the USE event. Information not initially 
available regarding the 80-nautical miles (148-km), 72-hour period 
prior to the event will be provided as soon as it becomes available. 
The Navy will provide NMFS investigative teams with additional relevant 
unclassified information as requested, if available.
    (b) [Reserved]


Sec.  218.95  Requirements for monitoring and reporting.

    (a) As outlined in the MITT Study Area Stranding Communication 
Plan, the Holder of the Authorization must notify NMFS immediately (or 
as soon as operational security considerations allow) if the specified 
activity identified in Sec.  218.90 is thought to have resulted in the 
mortality or injury of any marine mammals, or in any take of marine 
mammals not identified in Sec.  218.91.
    (b) The Holder of the LOA must conduct all monitoring and required 
reporting under the LOA, including abiding by the MITT Monitoring 
Project Description.
    (c) General notification of injured or dead marine mammals. Navy 
personnel shall ensure that NMFS (regional stranding coordinator) is 
notified immediately (or as soon as operational security considerations 
allow) if an injured or dead marine mammal is found during or shortly 
after, and in the vicinity of, an Navy training or testing activity 
utilizing mid- or high-frequency active sonar, or underwater explosive 
detonations. The Navy shall provide NMFS with species or description of 
the animal(s), the condition of the animal(s) (including carcass 
condition if the animal is dead), location, time of first discovery, 
observed behaviors (if alive), and photo or video (if available). The 
Navy shall consult the Stranding Response Plan to obtain more specific 
reporting requirements for specific circumstances.
    (d) Vessel strike. In the event that a Navy vessel strikes a whale, 
the Navy shall do the following:
    (1) Immediately report to NMFS (pursuant to the established 
Communication Protocol) the:
    (i) Species identification if known;
    (ii) Location (latitude/longitude) of the animal (or location of 
the strike if the animal has disappeared);
    (iii) Whether the animal is alive or dead (or unknown); and
    (iv) The time of the strike.

[[Page 46170]]

    (2) As soon as feasible, the Navy shall report to or provide to 
NMFS, the:
    (i) Size, length, and description (critical if species is not 
known) of animal;
    (ii) An estimate of the injury status (e.g., dead, injured but 
alive, injured and moving, blood or tissue observed in the water, 
status unknown, disappeared, etc.);
    (iii) Description of the behavior of the whale during event, 
immediately after the strike, and following the strike (until the 
report is made or the animal is no long sighted);
    (iv) Vessel class/type and operation status;
    (v) Vessel length
    (vi) Vessel speed and heading; and
    (vii) To the best extent possible, obtain
    (3) Within 2 weeks of the strike, provide NMFS:
    (i) A detailed description of the specific actions of the vessel in 
the 30-minute timeframe immediately preceding the strike, during the 
event, and immediately after the strike (e.g., the speed and changes in 
speed, the direction and changes in the direction, other maneuvers, 
sonar use, etc., if not classified); and
    (ii) A narrative description of marine mammal sightings during the 
event and immediately after, and any information as to sightings prior 
to the strike, if available; and
    (iii) Use established Navy shipboard procedures to make a camera 
available to attempt to capture photographs following a ship strike.
    (e) Annual MITT monitoring program report. (1) The Navy shall 
submit an annual report describing the implementation and results of 
the MITT Monitoring Program, described in Sec.  218.95. Data standards 
will be consistent to the extent appropriate across range complexes and 
study areas to allow for comparison in different geographic locations. 
Although additional information will be gathered, the protected species 
observers collecting marine mammal data pursuant to the MITT Monitoring 
Program shall, at a minimum, provide the same marine mammal observation 
data required in this section.
    (2) As an alternative, the Navy may submit a multi-range complex 
annual monitoring plan report to fulfill this requirement. Such a 
report would describe progress of knowledge made with respect to 
monitoring plan study questions across multiple Navy ranges associated 
with the ICMP. Similar study questions shall be treated together so 
that progress on each topic shall be summarized across all Navy ranges. 
The report need not include analyses and content that does not provide 
direct assessment of cumulative progress on the monitoring plan study 
questions. The report shall be submitted either 90 days after the 
calendar year, or 90 days after the conclusion of the monitoring year 
date to be determined by the Adaptive Management process.
    (f) Sonar exercise notification. The Navy shall submit to NMFS 
(specific contact information to be provided in the LOA) either an 
electronic (preferably) or verbal report within 15 calendar days after 
the completion of any major exercise indicating:
    (1) Location of the exercise.
    (2) Beginning and end dates of the exercise.
    (3) Type of exercise.
    (g) Annual MITT exercise and testing report. The Navy shall submit 
preliminary reports detailing the status of authorized sound sources 
within 21 days after the anniversary of the date of issuance of the 
LOA. The Navy shall submit a detailed report 3 months after the 
anniversary of the date of issuance of the LOA. The detailed annual 
report shall contain information on Major Training Exercises (MTE), 
Sinking Exercise (SINKEX) events, and a summary of sound sources used, 
as described below. The analysis in the detailed report will be based 
on the accumulation of data from the current year's report and data 
collected from previous reports. The detailed report shall contain 
information identified in Sec.  218.95(e)(1) and (2).
    (1) Major Training Exercises/SINKEX:
    (i) This section shall contain the reporting requirements for 
Coordinated and Strike Group exercises and SINKEX. Coordinated and 
Strike Group Major Training Exercises include:
    (A) Joint Multi-Strike Group Exercise (Valiant Shield).
    (B) Joint Expeditionary Exercise
    (ii) Exercise information for each MTE:
    (A) Exercise designator.
    (B) Date that exercise began and ended.
    (C) Location (operating area).
    (D) Number of items or hours (per the LOA) of each sound source bin 
(impulsive and non-impulsive) used in the exercise.
    (E) Number and types of vessels, aircraft, etc., participating in 
exercise.
    (F) Individual marine mammal sighting info for each sighting during 
each MTE:
    (1) Date/time/location of sighting.
    (2) Species (if not possible, indication of whale/dolphin).
    (3) Number of individuals.
    (4) Initial detection sensor.
    (5) Indication of specific type of platform the observation was 
made from (including, for example, what type of surface vessel or 
testing platform).
    (6) Length of time observers maintained visual contact with marine 
mammal(s).
    (7) Sea state.
    (8) Visibility.
    (9) Sound source in use at the time of sighting.
    (10) Indication of whether animal is <200 yd, 200 to 500 yd, 500 to 
1,000 yd, 1,000 to 2,000 yd, or >2,000 yd from sound source.
    (11) Mitigation Implementation--Whether operation of sonar sensor 
was delayed, or sonar was powered or shut down, and how long the delay 
was; or whether navigation was changed or delayed.
    (12) If source in use is a hull-mounted sonar, relative bearing of 
animal from ship, and estimation of animal's motion relative to ship 
(opening, closing, parallel).
    (13) Observed behavior--Watchstanders shall report, in plain 
language and without trying to categorize in any way, the observed 
behavior of the animal(s) (such as animal closing to bow ride, 
paralleling course/speed, floating on surface and not swimming, etc.) 
and if any calves present.
    (iii) An evaluation (based on data gathered during all of the MTEs) 
of the effectiveness of mitigation measures designed to minimize the 
received level to which marine mammals may be exposed. This evaluation 
shall identify the specific observations that support any conclusions 
the Navy reaches about the effectiveness of the mitigation.
    (iv) Exercise information for each SINKEX:
    (A) List of the vessels and aircraft involved in the SINKEX.
    (B) Location (operating area).
    (C) Chronological list of events with times, including time of 
sunrise and sunset, start and stop time of all marine species surveys 
that occur before, during, and after the SINKEX, and ordnance used.
    (D) Visibility and/or weather conditions, wind speed, cloud cover, 
etc. throughout exercise if it changes.
    (E) Aircraft used in the surveys, flight altitude, and flight speed 
and the area covered by each of the surveys, given in coordinates, map, 
or square miles.
    (F) Passive acoustic monitoring details (number of sonobuoys, area, 
detections of biologic activity, etc.).
    (G) Individual marine mammal sighting info for each sighting that 
required mitigation to be implemented:
    (1) Date/time/location of sighting.

[[Page 46171]]

    (2) Species (if not possible, indication of whale/dolphin).
    (3) Number of individuals.
    (4) Initial detection sensor.
    (5) Indication of specific type of platform the observation was 
made from (including, for example, what type of surface vessel or 
platform).
    (6) Length of time observers maintained visual contact with marine 
mammal(s).
    (7) Sea state.
    (8) Visibility.
    (9) Indication of whether animal is <200 yd, 200-500 yd, 500-1,000 
yd, 1,000-2,000 yd, or >2,000 yd from the target.
    (10) Mitigation implementation--Whether the SINKEX was stopped or 
delayed and length of delay.
    (11) Observed behavior--Watchstanders shall report, in plain 
language and without trying to categorize in any way, the observed 
behavior of the animals (such as animal closing to bow ride, 
paralleling course/speed, floating on surface and not swimming, etc.), 
and if any calves present.
    (H) List of the ordnance used throughout the SINKEX and net 
explosive weight (NEW) of each weapon and the combined NEW.
    (2) Summary of sources used. (i) This section shall include the 
following information summarized from the authorized sound sources used 
in all training and testing events:
    (A) Total annual or quantity (per the LOA) of each bin of sonar or 
other non-impulsive source;
    (B) Total annual expended/detonated rounds (missiles, bombs, etc.) 
for each explosive bin; and
    (C) Improved Extended Echo-Ranging System (IEER)/sonobuoy summary, 
including:
    (1) Total expended/detonated rounds (buoys).
    (2) Total number of self-scuttled IEER rounds.
    (3) Geographic information presentation. The reports shall present 
an annual (and seasonal, where practical) depiction of training 
exercises and testing bin usage geographically across the Study Area.
    (h) Five-year close-out exercise and testing report.--This report 
will be included as part of the 2020 annual exercise or testing report. 
This report will provide the annual totals for each sound source bin 
with a comparison to the annual allowance and the 5-year total for each 
sound source bin with a comparison to the 5-year allowance. 
Additionally, if there were any changes to the sound source allowance, 
this report will include a discussion of why the change was made and 
include the analysis to support how the change did or did not result in 
a change in the FEIS and final rule determinations. The report will be 
submitted 3 months after the expiration of the rule. NMFS will submit 
comments on the draft close-out report, if any, within 3 months of 
receipt. The report will be considered final after the Navy has 
addressed NMFS' comments, or 3 months after the submittal of the draft 
if NMFS does not provide comments.


Sec.  218.96  Applications for Letters of Authorization.

    To incidentally take marine mammals pursuant to the regulations in 
this subpart, the U.S. citizen (as defined by Sec.  216.106 of this 
chapter) conducting the activity identified in Sec.  218.90(c) (the 
U.S. Navy) must apply for and obtain either an initial LOA in 
accordance with Sec.  218.97 or a renewal under Sec.  218.98.


Sec.  218.97  Letters of Authorization.

    (a) An LOA, unless suspended or revoked, will be valid for a period 
of time not to exceed the period of validity of this subpart.
    (b) The LOA will set forth:
    (1) Permissible methods and extent of incidental taking;
    (2) Means of effecting the least practicable adverse impact on the 
species, its habitat, and on the availability of the species for 
subsistence uses (i.e., mitigation); and
    (3) Requirements for mitigation, monitoring and reporting.
    (c) Issuance of the LOA will be based on a determination that the 
total number of marine mammals taken by the activity as a whole will 
have no more than a negligible impact on the affected species or stock 
of marine mammal(s).


Sec.  218.98  Renewals and modifications of Letters of Authorization.

    (a) A Letter of Authorization issued under Sec. Sec.  216.106 and 
218.97 of this chapter for the activity identified in Sec.  218.90(c) 
will be renewed or modified upon request of the applicant, provided 
that:
    (1) The proposed specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are within the 
scope of those described and analyzed for these regulations (excluding 
changes made pursuant to the adaptive management provision of this 
chapter), and;
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA under these regulations were 
implemented.
    (b) For LOA modification or renewal requests by the applicant that 
include changes to the activity or the mitigation, monitoring, or 
reporting (excluding changes made pursuant to the adaptive management 
provision of this chapter) that do not change the findings made for the 
regulations or result in no more than a minor change in the total 
estimated number of takes (or distribution by species or years). NMFS 
may publish a notice of proposed LOA in the Federal Register, including 
the associated analysis illustrating the change, and solicit public 
comment before issuing the LOA.
    (c) An LOA issued under Sec. Sec.  216.106 and 218.97 of this 
chapter for the activity identified in Sec.  218.94 of this chapter may 
be modified by NMFS under the following circumstances:
    (1) Adaptive management. NMFS may modify (including augmenting, 
changing, or reducing) the existing mitigation, monitoring, or 
reporting measures (after consulting with the Navy regarding the 
practicability of the modifications) if doing so creates a reasonable 
likelihood of more effectively accomplishing the goals of the 
mitigation and monitoring.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, and reporting measures in an LOA:
    (A) Results from Navy's monitoring from the previous year(s);
    (B) Results from other marine mammal and/or sound research or 
studies; or
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent, or number not authorized by these regulations or 
subsequent LOA.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
would publish a notice of proposed LOA in the Federal Register and 
solicit public comment.
    (2) Emergencies. If NMFS determines that an emergency exists that 
poses a significant risk to the well-being of the species or stocks of 
marine mammals specified in Sec.  218.92(c), an LOA may be modified 
without prior notification and an opportunity for public comment. 
Notification would be published in the Federal Register within 30 days 
of the action.

[FR Doc. 2015-18633 Filed 7-31-15; 8:45 am]
 BILLING CODE 3510-22-P