[Federal Register Volume 85, Number 148 (Friday, July 31, 2020)]
[Rules and Regulations]
[Pages 46302-46419]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-15651]



[[Page 46301]]

Vol. 85

Friday,

No. 148

July 31, 2020

Part III





 Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 218





Taking and Importing Marine Mammals; Taking Marine Mammals Incidental 
to the U.S. Navy Training and Testing Activities in the Mariana Islands 
Training and Testing (MITT) Study Area; Final Rule

  Federal Register / Vol. 85, No. 148 / Friday, July 31, 2020 / Rules 
and Regulations  

[[Page 46302]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 200713-0188]
RIN 0648-BJ00


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to the U.S. Navy Training and Testing Activities in the 
Mariana Islands Training and Testing (MITT) Study Area

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

ACTION: Final rule; notification of issuance of Letter of 
Authorization.

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SUMMARY: NMFS, upon request from the U.S. Navy (Navy), issues these 
regulations pursuant to the Marine Mammal Protection Act (MMPA) to 
govern the taking of marine mammals incidental to the training and 
testing activities conducted in the Mariana Islands Training and 
Testing (MITT) Study Area. The Navy's activities qualify as military 
readiness activities pursuant to the MMPA, as amended by the National 
Defense Authorization Act for Fiscal Year 2004 (2004 NDAA). These 
regulations, which allow for the issuance of a Letter of Authorization 
(LOA) for the incidental take of marine mammals during the described 
activities and timeframes, prescribe the permissible methods of taking 
and other means of effecting the least practicable adverse impact on 
marine mammal species and their habitat, and establish requirements 
pertaining to the monitoring and reporting of such taking.

DATES: Effective from July 31, 2020, to July 30, 2027.

ADDRESSES: A copy of the Navy's application, NMFS' proposed and final 
rules and subsequent LOA for the existing regulations, and other 
supporting documents and documents cited herein may be obtained online 
at: www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. In case 
of problems accessing these documents, please use the contact listed 
here (see FOR FURTHER INFORMATION CONTACT).

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

SUPPLEMENTARY INFORMATION:

Purpose of Regulatory Action

    These regulations, issued under the authority of the MMPA (16 
U.S.C. 1361 et seq.), provide the framework for authorizing the take of 
marine mammals incidental to the Navy's training and testing activities 
(which qualify as military readiness activities) from the use of sonar 
and other transducers and in-water detonations throughout the MITT 
Study Area. The MITT Study Area includes the seas off the coasts of 
Guam and the Commonwealth of the Northern Mariana Islands (CNMI), the 
in-water areas around the Mariana Islands Range Complex (MIRC), the 
transit corridor between the MIRC and the Hawaii Range Complex (HRC), 
and select pierside and harbor locations. The transit corridor is 
outside the geographic boundaries of the MIRC and represents a great 
circle route across the high seas for Navy vessels transiting between 
the MIRC and the HRC. The planned activities also include various 
activities in Apra Harbor such as sonar maintenance alongside Navy 
piers located in Inner Apra Harbor.
    NMFS received an application from the Navy requesting seven-year 
regulations and an authorization to incidentally take individuals of 
multiple species of marine mammals (``Navy's rulemaking/LOA 
application'' or ``Navy's application''). Take is anticipated to occur 
by Level A and Level B harassment incidental to the Navy's training and 
testing activities, with no serious injury or mortality expected or 
authorized.
    Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs 
the Secretary of Commerce (as delegated to NMFS) 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, after notice and public comment, the agency makes certain findings 
and issues regulations that set forth permissible methods of taking 
pursuant to that activity, as well as monitoring and reporting 
requirements. Section 101(a)(5)(A) of the MMPA and the implementing 
regulations at 50 CFR part 216, subpart I, provide the legal basis for 
issuing this final rule and the subsequent LOAs. As directed by this 
legal authority, this final rule contains mitigation, monitoring, and 
reporting requirements.

Summary of Major Provisions Within the Final Rule

    The following is a summary of the major provisions of this final 
rule regarding the Navy's activities. Major provisions include, but are 
not limited to:
     The use of defined powerdown and shutdown zones (based on 
activity);
     Measures to eliminate the likelihood of ship strikes;
     Activity limitations in certain areas and times that are 
biologically important (i.e., for foraging, migration, reproduction) 
for marine mammals; and
     Implementation of a Notification and Reporting Plan (for 
dead or live stranded marine mammals); and
     Implementation of a robust monitoring plan to improve our 
understanding of the environmental effects resulting from the Navy 
training and testing activities.
    Additionally, the rule includes an adaptive management component 
that allows for timely modification of mitigation or monitoring 
measures based on new information, when appropriate.

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA direct the 
Secretary of Commerce (as delegated to NMFS) 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 and the opportunity to submit 
comments.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stocks and will not have an unmitigable adverse impact on the 
availability of the species or stocks for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other means of effecting the least practicable adverse 
impact on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in this rule as 
``mitigation measures''); and requirements pertaining to the monitoring 
and reporting of such takings. The MMPA defines ``take'' to mean to 
harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or 
kill any marine mammal. The Analysis and Negligible

[[Page 46303]]

Impact Determination section below discusses the definition of 
``negligible impact.''
    The NDAA for Fiscal Year 2004 (2004 NDAA) (Pub. L. 108-136) amended 
section 101(a)(5) of the MMPA to remove the ``small numbers'' and 
``specified geographical region'' provisions indicated above and 
amended the definition of ``harassment'' as applied to a ``military 
readiness activity.'' The definition of harassment for military 
readiness activities (section 3(18)(B) of the MMPA) is (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). In addition, 
the 2004 NDAA amended the MMPA as it relates to military readiness 
activities such that the least practicable adverse impact analysis 
shall include consideration of personnel safety, practicality of 
implementation, and impact on the effectiveness of the military 
readiness activity.
    More recently, section 316 of the NDAA for Fiscal Year 2019 (2019 
NDAA) (Pub. L. 115-232), signed on August 13, 2018, amended the MMPA to 
allow incidental take rules for military readiness activities under 
section 101(a)(5)(A) to be issued for up to seven years. Prior to this 
amendment, all incidental take rules under section 101(a)(5)(A) were 
limited to five years.

Summary and Background of Request

    On February 11, 2019, NMFS received an application from the Navy 
for authorization to take marine mammals by Level A and Level B 
harassment incidental to training and testing activities (categorized 
as military readiness activities) from the use of sonar and other 
transducers and in-water detonations in the MITT Study Area over a 
seven-year period beginning when the current authorization expires. On 
March 15, 2019, we published a notice of receipt of application (NOR) 
in the Federal Register (84 FR 9495), requesting comments and 
information related to the Navy's request for 30 days. On January 31, 
2020, we published a notice of the proposed rulemaking (85 FR 5782) and 
requested comments and information related to the Navy's request for 45 
days. All comments received during the NOR and the proposed rulemaking 
comment periods were considered in this final rule. Comments received 
on the proposed rule are addressed in this final rule in the Comments 
and Responses section. The following types of training and testing, 
which are classified as military readiness activities pursuant to the 
MMPA, as amended by the 2004 NDAA, will be covered under the 
regulations and LOA: Amphibious warfare (in-water detonations), anti-
submarine warfare (sonar and other transducers, in-water detonations), 
surface warfare (in-water detonations), and other testing and training 
(sonar and other transducers). The activities will not include any pile 
driving/removal or use of air guns.
    This will be the third time NMFS has promulgated incidental take 
regulations pursuant to the MMPA relating to similar military readiness 
activities in the MITT Study Area, following those effective from 
August 3, 2010, through August 3, 2015 (75 FR 45527; August 3, 2010) 
and from August 3, 2015 through August 3, 2020 (80 FR 46112; August 3, 
2015). For this third rulemaking, the Navy is proposing to conduct 
similar activities as they have conducted over the past nine years 
under the previous rulemakings.
    The Navy's mission is to organize, train, equip, and maintain 
combat-ready naval forces capable of winning wars, deterring 
aggression, and maintaining freedom of the seas. This mission is 
mandated by Federal law (10 U.S.C. 8062), which requires the readiness 
of the naval forces of the United States. The Navy executes this 
responsibility by training and testing at sea, often in designated 
operating areas (OPAREA) and testing and training ranges. The Navy must 
be able to access and utilize these areas and associated sea space and 
air space in order to develop and maintain skills for conducting naval 
operations. The Navy's testing activities ensure naval forces are 
equipped with well-maintained systems that take advantage of the latest 
technological advances. The Navy's research and acquisition community 
conducts military readiness activities that involve testing. The Navy 
tests ships, aircraft, weapons, combat systems, sensors, and related 
equipment, and conducts scientific research activities to achieve and 
maintain military readiness.
    The tempo and types of training and testing activities fluctuate 
because of the introduction of new technologies, the evolving nature of 
international events, advances in warfighting doctrine and procedures, 
and changes in force structure (e.g., organization of ships, 
submarines, aircraft, weapons, and personnel). Such developments 
influence the frequency, duration, intensity, and location of required 
training and testing activities, but the basic nature of sonar and 
explosive events conducted in the MITT Study Area has remained the 
same.
    The Navy's rulemaking/LOA application reflects the most up-to-date 
compilation of training and testing activities deemed necessary to 
accomplish military readiness requirements. The types and numbers of 
activities included in the rule account for fluctuations in training 
and testing in order to meet evolving or emergent military readiness 
requirements. These regulations will cover training and testing 
activities that will occur for a seven-year period following the 
expiration of the current MMPA authorization for the MITT Study Area, 
which expires on August 3, 2020.

Description of the Specified Activity

    Additional detail regarding the specified activity was provided in 
our Federal Register notice of proposed rulemaking (85 FR 5782; January 
31, 2020); please see that notice of proposed rulemaking or the Navy's 
application for more information. In addition, since publication of the 
proposed rule, additional mitigation measures have been added, which 
are discussed in detail in the Mitigation Measures section of this 
rule. The Navy requested authorization to take marine mammals 
incidental to conducting training and testing activities. The Navy has 
determined that acoustic and explosive stressors are most likely to 
result in impacts on marine mammals that could rise to the level of 
harassment, and NMFS concurs with this determination. Descriptions of 
these activities are provided in section 2 of the 2020 MITT Final 
Supplemental Environmental Impact Statement (FSEIS)/Overseas EIS (OEIS) 
(2020 MITT FSEIS/OEIS) (U.S. Department of the Navy, 2020) and in the 
Navy's rule making/LOA application (https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities) and are summarized here.

Dates and Duration

    The specified activities can occur at any time during the seven-
year period of validity of the regulations, with the exception of the 
activity types and time periods for which limitations have explicitly 
been identified (see Mitigation Measures section). The planned number 
of training and testing activities are described in the Detailed 
Description of the Specified Activities section (Table 3).

[[Page 46304]]

Geographical Region

    The MITT Study Area is comprised of three components: (1) The MIRC, 
(2) additional areas on the high seas, and (3) a transit corridor 
between the MIRC and the HRC. The MIRC includes the waters south of 
Guam to north of Pagan (CNMI), and from the Pacific Ocean east of the 
Mariana Islands to the Philippine Sea to the west, encompassing 501,873 
square nautical miles (nmi\2\) of open ocean. The additional areas of 
the high seas include the area to the north of the MIRC that is within 
the U.S. Exclusive Economic Zone (EEZ) of the CNMI and the areas to the 
west of the MIRC. The transit corridor is outside the geographic 
boundaries of the MIRC and represents a great circle route (i.e., the 
shortest distance) across the high seas for Navy ships transiting 
between the MIRC and the HRC. Although not part of any defined range 
complex, the transit corridor is important to the Navy in that it 
provides available air, sea, and undersea space where vessels and 
aircraft conduct training and testing while in transit. While in 
transit and along the corridor, vessels and aircraft will, at times, 
conduct basic and routine unit-level activities such as gunnery and 
sonar training. Ships also conduct sonar maintenance, which includes 
active sonar transmissions.
    Additionally, the MITT Study Area includes pierside locations in 
the Apra Harbor Naval Complex where surface ship and submarine sonar 
maintenance occur. Activities in Apra Harbor include channels and 
routes to and from the Navy port in the Apra Harbor Naval Complex, and 
associated wharves and facilities within the Navy port.

Primary Mission Areas

    The Navy categorizes its at-sea activities into functional warfare 
areas called primary mission areas. These activities generally fall 
into the following eight primary mission areas: Air warfare; amphibious 
warfare; anti-submarine warfare (ASW); electronic warfare; 
expeditionary warfare; mine warfare (MIW); strike warfare; and surface 
warfare (SUW). Most activities addressed in the MITT Study Area are 
categorized under one of the primary mission areas. Activities that do 
not fall within one of these areas are listed as ``other activities.'' 
Each warfare community (surface, subsurface, aviation, and 
expeditionary warfare) may train in some or all of these primary 
mission areas. The testing community also categorizes most, but not 
all, of its testing activities under these primary mission areas. A 
description of the sonar, munitions, targets, systems, and other 
material used during training and testing activities within these 
primary mission areas is provided in the 2020 MITT FSEIS/OEIS Appendix 
A (Training and Testing Activities Descriptions).
    The Navy describes and analyzes the effects of its activities 
within the 2020 MITT FSEIS/OEIS. In its assessment, the Navy concluded 
that sonar and other transducers and in-water detonations were the 
stressors that would result in impacts on marine mammals that could 
rise to the level of harassment as defined under the MMPA. Therefore, 
the Navy's rulemaking/LOA application provides the Navy's assessment of 
potential effects from these stressors in terms of the various warfare 
mission areas in which they will be conducted. Those mission areas 
include the following:

[ssquf] Amphibious warfare (underwater detonations)
[ssquf] ASW (sonar and other transducers, underwater detonations)
[ssquf] MIW (sonar and other transducers, underwater detonations)
[ssquf] SUW (underwater detonations)
[ssquf] Other training and testing activities (sonar and other 
transducers)

    The Navy's training and testing activities in air warfare, 
electronic warfare, and expeditionary warfare do not involve sonar and 
other transducers, underwater detonations, or any other stressors that 
could result in harassment, serious injury, or mortality of marine 
mammals. Therefore, the activities in air, electronic, and 
expeditionary warfare areas are not discussed further in this rule, but 
are analyzed fully in the 2020 MITT FSEIS/OEIS. Additional detail 
regarding the primary mission areas was provided in our Federal 
Register notice of proposed rulemaking (85 FR 5782; January 31, 2020); 
please see that notice of proposed rulemaking or the Navy's application 
for more information.

Overview of Major Training Activities and Exercises Within the MITT 
Study Area

    A major training exercise (MTE) for purposes of this rulemaking is 
comprised of several unit-level activities conducted by several units 
operating together, commanded and controlled by a single Commander, and 
typically generating more than 100 hours of active sonar. These 
exercises typically employ an exercise scenario developed to train and 
evaluate the exercise participants in tactical and operational tasks. 
In an MTE, most of the activities being directed and coordinated by the 
Commander in charge of the exercise are identical in nature to the 
activities conducted during individual, crew, and smaller unit-level 
training events. In an MTE, however, these disparate training tasks are 
conducted in concert, rather than in isolation.
    Exercises may also be categorized as integrated or coordinated ASW 
exercises. The distinction between integrated and coordinated ASW 
exercises is how the units are being controlled. Integrated ASW 
exercises are controlled by an existing command structure, and 
generally occur during the Integrated Phase of the training cycle. 
Coordinated exercises may have a command structure stood up solely for 
the event; for example, the commanding officer of a ship may be placed 
in tactical command of other ships for the duration of the exercise. 
Not all integrated ASW exercises are considered MTEs, due to their 
scale, number of participants, duration, and amount of active sonar. 
The distinction between large, medium, and small integrated or 
coordinated exercises is based on the scale of the exercise (i.e., 
number of ASW units participating), the length of the exercise, and the 
total number of active sonar hours. NMFS considered the effects of all 
training exercises, not just these major, integrated, and coordinated 
training exercises in this rule.

Overview of Testing Activities Within the MITT Study Area

    The Navy's research and acquisition community engages in a broad 
spectrum of testing activities in support of the Fleet. These 
activities include, but are not limited to, basic and applied 
scientific research and technology development; testing, evaluation, 
and maintenance of systems (missiles, radar, and sonar) and platforms 
(surface ships, submarines, and aircraft); and acquisition of systems 
and platforms. The individual commands within the research and 
acquisition community include Naval Air Systems Command, Naval Sea 
Systems Command, and Office of Naval Research.

Description of Stressors

    The Navy uses a variety of sensors, platforms, weapons, and other 
devices, including ones used to ensure the safety of Sailors and 
Marines, to meet its mission. Training and testing with these systems 
may introduce acoustic (sound) energy or shock waves from explosives 
into the environment. The following subsections describe the acoustic 
and explosive stressors for marine mammals and their habitat (including 
prey species) within the MITT Study Area. Because of the complexity of 
analyzing

[[Page 46305]]

sound propagation in the ocean environment, the Navy relied on acoustic 
models in its environmental analyses and rulemaking/LOA application 
that considered sound source characteristics and varying ocean 
conditions across the MITT Study Area. Stressor/resource interactions 
that were determined to have de minimis or no impacts (i.e., vessel, 
aircraft, or weapons noise, and explosions in air) were not carried 
forward for analysis in the Navy's rulemaking/LOA application. NMFS 
reviewed the Navy's analysis and conclusions on de minimis sources and 
finds them complete and supportable.
    Acoustic stressors include acoustic signals emitted into the water 
for a specific purpose, such as sonar and other transducers (devices 
that convert energy from one form to another--in this case, into sound 
waves), as well as incidental sources of broadband sound produced as a 
byproduct of vessel movement and use of weapons or other deployed 
objects. Explosives also produce broadband sound but are characterized 
separately from other acoustic sources due to their unique hazardous 
characteristics. Characteristics of each of these sound sources are 
described in the following sections.
    In order to better organize and facilitate the analysis of 
approximately 300 sources of underwater sound used for training and 
testing by the Navy, including sonar and other transducers and 
explosives, a series of source classifications, or source bins, was 
developed. The source classification bins do not include the broadband 
sounds produced incidental to vessel or aircraft transits, weapons 
firing, and bow shocks.
    The use of source classification bins provides the following 
benefits:
    [ssquf] Provides the ability for new sensors or munitions to be 
covered under existing authorizations, as long as those sources fall 
within the parameters of a ``bin;''
    [ssquf] Improves efficiency of source utilization data collection 
and reporting requirements anticipated under the MMPA authorizations;
    [ssquf] Ensures a conservative approach to all impact estimates, as 
all sources within a given class are modeled as the most impactful 
source (highest source level, longest duty cycle, or largest net 
explosive weight) within that bin;
    [ssquf] Allows analyses to be conducted in a more efficient manner, 
without any compromise of analytical results; and
    [ssquf] Provides a framework to support the reallocation of source 
usage (hours/explosives) between different source bins, as long as the 
total numbers of 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.
Sonar and Other Transducers
    Active sonar and other transducers emit non-impulsive sound waves 
into the water to detect objects, navigate safely, and communicate. 
Passive sonars differ from active sound sources in that they do not 
emit acoustic signals; rather, they only receive acoustic information 
about the environment, or listen. In this rule, the terms sonar and 
other transducers will be used to indicate active sound sources unless 
otherwise specified.
    The Navy employs a variety of sonars and other transducers to 
obtain and transmit information about the undersea environment. Some 
examples are mid-frequency hull-mounted sonars used to find and track 
enemy submarines; high-frequency small object detection sonars used to 
detect mines; high-frequency underwater modems used to transfer data 
over short ranges; and extremely high-frequency (greater than 200 
kilohertz (kHz)) doppler sonars used for navigation, like those used on 
commercial and private vessels. The characteristics of these sonars and 
other transducers, such as source level, beam width, directivity, and 
frequency, depend on the purpose of the source. Higher frequencies can 
carry more information or provide more information about objects off 
which they reflect, but attenuate more rapidly. Lower frequencies 
attenuate less rapidly, so may detect objects over a longer distance, 
but with less detail.
    Additional detail regarding sound sources and platforms and 
categories of acoustic stressors was provided in our Federal Register 
notice of proposed rulemaking (85 FR 5782; January 31, 2020); please 
see that notice of proposed rulemaking or the Navy's application for 
more information.
    Sonars and other transducers are grouped into classes that share an 
attribute, such as frequency range or purpose of use. As detailed 
below, classes are further sorted by bins based on the frequency or 
bandwidth; source level; and, when warranted, the application in which 
the source would be used. Unless stated otherwise, a reference distance 
of 1 meter (m) is used for sonar and other transducers.
     Frequency of the non-impulsive acoustic source;
    [cir] Low-frequency sources operate below 1 kHz;
    [cir] Mid-frequency sources operate at and 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 kHz but below 
200 kHz;
     Sound pressure level of the non-impulsive source;
    [cir] Greater than 160 decibels (dB) re 1 micro Pascal ([mu]Pa), 
but less than 180 dB re 1 [mu]Pa;
    [cir] Equal to 180 dB re 1 [mu]Pa and up to 200 dB re 1 [mu]Pa;
    [cir] Greater than 200 dB re 1 [mu]Pa;
     Application in which the source would be used;
    [cir] Sources with similar functions that have similar 
characteristics, such as pulse length (duration of each pulse), beam 
pattern, and duty cycle.
    The bins used for classifying active sonars and transducers that 
are quantitatively analyzed in the MITT Study Area are shown in Table 1 
below. While general parameters or source characteristics are shown in 
the table, actual source parameters are classified.

Table 1--Sonar and Transducers Quantitatively Analyzed in the MITT Study
                                  Area
------------------------------------------------------------------------
     Source class category             Bin              Description
------------------------------------------------------------------------
Low-Frequency (LF): Sources      LF4............  LF sources equal to
 that produce signals less than  LF5............   180 dB and up to 200
 1 kHz.                                            dB.
                                                  LF sources less than
                                                   180 dB.
Mid-Frequency (MF): Tactical     MF1............  Hull-mounted surface
 and non-tactical sources that                     ship sonars (e.g., AN/
 produce signals between 1 and                     SQS-53C and AN/SQS-
 10 kHz.                                           60).
                                 MF1K...........  Kingfisher mode
                                                   associated with MF1
                                                   sonars.
                                 MF3............  Hull-mounted submarine
                                                   sonars (e.g., AN/BQQ-
                                                   10).
                                 MF4............  Helicopter-deployed
                                                   dipping sonars (e.g.,
                                                   AN/AQS-22).
                                 MF5............  Active acoustic
                                                   sonobuoys (e.g.,
                                                   DICASS).
                                 MF6............  Underwater sound
                                                   signal devices (e.g.,
                                                   MK 84 SUS).

[[Page 46306]]

 
                                 MF9............  Sources (equal to 180
                                                   dB and up to 200 dB)
                                                   not otherwise binned.
                                 MF11...........  Hull-mounted surface
                                                   ship sonars with an
                                                   active duty cycle
                                                   greater than 80
                                                   percent.
                                 MF12...........  Towed array surface
                                                   ship sonars with an
                                                   active duty cycle
                                                   greater than 80
                                                   percent.
High-Frequency (HF): Tactical    HF1............  Hull-mounted submarine
 and non-tactical sources that   HF3............   sonars (e.g., AN/BQQ-
 produce signals between 10 and                    10).
 100 kHz.                                         Other hull-mounted
                                                   submarine sonars
                                                   (classified).
                                 HF4............  Mine detection,
                                                   classification, and
                                                   neutralization sonar
                                                   (e.g., AN/SQS-20).
                                 HF6............  Sources (equal to 180
                                                   dB and up to 200 dB)
                                                   not otherwise binned.
Anti-Submarine Warfare (ASW):    ASW1...........  MF systems operating
 Tactical sources (e.g., active  ASW2...........   above 200 dB.
 sonobuoys and acoustic                           MF Multistatic Active
 countermeasures systems) used                     Coherent sonobuoy
 during ASW training and                           (e.g., AN/SSQ-125).
 testing activities.
                                 ASW3...........  MF towed active
                                                   acoustic
                                                   countermeasure
                                                   systems (e.g., AN/SLQ-
                                                   25).
                                 ASW4...........  MF expendable active
                                                   acoustic device
                                                   countermeasures
                                                   (e.g., MK 3).
                                 ASW5...........  MF sonobuoys with high
                                                   duty cycles.
Torpedoes (TORP): Active         TORP1..........  Lightweight torpedo
 acoustic signals produced by                      (e.g., MK 46, MK 54,
 torpedoes.                                        or Anti-Torpedo
                                                   Torpedo).
                                 TORP2..........  Heavyweight torpedo
                                                   (e.g., MK 48).
                                 TORP3..........  Heavyweight torpedo
                                                   (e.g., MK 48).
Forward Looking Sonar (FLS):     FLS2...........  HF sources with short
 Forward or upward looking                         pulse lengths, narrow
 object avoidance sonars used                      beam widths, and
 for ship navigation and safety.                   focused beam
                                                   patterns.
Acoustic Modems (M): Sources     M3.............  MF acoustic modems
 used to transmit data.                            (greater than 190
                                                   dB).
Synthetic Aperture Sonars        SAS2...........  HF SAS systems.
 (SAS): Sonars used to form      SAS4...........  MF to HF broadband
 high-resolution images of the                     mine countermeasure
 seafloor.                                         sonar.
------------------------------------------------------------------------

Explosives
    This section describes the characteristics of explosions during 
naval training and testing. The activities analyzed in the Navy's 
rulemaking/LOA application that use explosives are described in 
Appendix A (Training and Testing Activities Descriptions) of the 2020 
MITT FSEIS/OEIS. Explanations of the terminology and metrics used when 
describing explosives in the Navy's rule making/LOA application are 
also in Appendix H (Acoustic and Explosive Concepts) of the 2020 MITT 
FSEIS/OEIS.
    The near-instantaneous rise from ambient to an extremely high peak 
pressure is what makes an explosive shock wave potentially damaging. 
Farther from an explosive, the peak pressures decay and the explosive 
waves propagate as an impulsive, broadband sound. Several parameters 
influence the effect of an explosive: The weight of the explosive in 
the warhead, the type of explosive material, the boundaries and 
characteristics of the propagation medium, and, in water, the 
detonation depth and the depth of the receiver (i.e., marine mammal). 
The net explosive weight, which is the explosive power of a charge 
expressed as the equivalent weight of trinitrotoluene (TNT), accounts 
for the first two parameters. The effects of these factors are 
explained in Appendix H (Acoustic and Explosive Concepts) of the 2020 
MITT FSEIS/OEIS.
    Explosive detonations during training and testing activities are 
associated with high-explosive munitions, including, but not limited 
to, bombs, missiles, rockets, naval gun shells, torpedoes, mines, 
demolition charges, and explosive sonobuoys. Explosive detonations 
during training and testing involving the use of high-explosive 
munitions (including bombs, missiles, and naval gun shells) could occur 
in the air or at the water's surface. Explosive detonations associated 
with torpedoes and explosive sonobuoys could occur in the water column; 
mines and demolition charges could be detonated in the water column or 
on the ocean bottom. Most detonations will occur in waters greater than 
200 ft in depth, and greater than 3 nmi from shore, with the exception 
of three existing mine warfare areas (Outer Apra Harbor, Piti, and Agat 
Bay). Nearshore small explosive charges only occur at the three mine 
warfare areas. Piti and Agat Bay, while nearshore, are in very deep 
water and used for floating mine neutralization activities. In order to 
better organize and facilitate the analysis of explosives used by the 
Navy during training and testing that could detonate in water or at the 
water surface, explosive classification bins were developed. The use of 
explosive classification bins provides the same benefits as described 
for acoustic source classification bins discussed above and in Section 
1.4.1 (Acoustic Stressors) of the Navy's rulemaking/LOA application.
    Explosives detonated in water are binned by net explosive weight. 
The bins of explosives that are planned for use in the MITT Study Area 
are shown in Table 2 below.

           Table 2--Explosives Analyzed in the MITT Study Area
------------------------------------------------------------------------
               Net explosive
    Bin         weight (lb)             Example explosive source
------------------------------------------------------------------------
E1........            0.1-0.25  Medium-caliber projectiles.

[[Page 46307]]

 
E2........           >0.25-0.5  Anti-swimmer grenade.
E3........            >0.5-2.5  57 mm projectile.
E4........              >2.5-5  Mine neutralization charge.
E5........               >5-10  5 in projectiles.
E6........              >10-20  Hellfire missile.
E8........             >60-100  250 lb bomb; Lightweight torpedo.
E9........            >100-250  500 lb bomb.
E10.......            >250-500  1,000 lb bomb.
E11.......            >500-650  Heavyweight torpedo.
E12.......          >650-1,000  2,000 lb bomb.
------------------------------------------------------------------------
Notes: (1) Net Explosive Weight refers to the equivalent amount of TNT.
  The actual weight of a munition may be larger due to other components;
  (2) in = inch(es), lb = pound(s), ft = feet.

    Propagation of explosive pressure waves in water is highly 
dependent on environmental characteristics such as bathymetry, bottom 
type, water depth, temperature, and salinity, which affect how the 
pressure waves are reflected, refracted, or scattered; the potential 
for reverberation; and interference due to multi-path propagation. In 
addition, absorption greatly affects the distance over which higher-
frequency components of explosive broadband noise can propagate. 
Appendix H (Acoustic and Explosive Concepts) of the 2020 MITT FSEIS/
OEIS explains the characteristics of explosive detonations and how the 
above factors affect the propagation of explosive energy in the water.
    Marine mammals could be exposed to fragments from underwater 
explosions associated with the specified activities. When explosive 
ordnance (e.g., bomb or missile) detonates, fragments of the weapon are 
thrown at high-velocity from the detonation point, which can injure or 
kill marine mammals if they are struck. These fragments may be of 
variable size and are ejected at supersonic speed from the detonation. 
The casing fragments will be ejected at velocities much greater than 
debris from any target due to the proximity of the casing to the 
explosive material. Risk of fragment injury reduces exponentially with 
distance as the fragment density is reduced. Fragments underwater tend 
to be larger than fragments produced by in-air explosions (Swisdak and 
Montaro, 1992). Underwater, the friction of the water would quickly 
slow these fragments to a point where they no longer pose a threat. 
Opposingly, the blast wave from an explosive detonation moves 
efficiently through the seawater. Because the ranges to mortality and 
injury due to exposure to the blast wave are likely to far exceed the 
zone where fragments could injure or kill an animal, the thresholds for 
assessing the likelihood of harassment from a blast, which are also 
used to inform mitigation zones, are assumed to encompass risk due to 
fragmentation.

Detailed Description of the Specified Activities

Planned Training and Testing Activities

    The Navy's Operational Commands and various System Commands have 
identified activity levels that are needed in the MITT Study Area to 
ensure naval forces have sufficient training, maintenance, and new 
technology to meet Navy missions in the Pacific. Training prepares Navy 
personnel to be proficient in safely operating and maintaining 
equipment, weapons, and systems to conduct assigned missions. Navy 
research develops new science and technology followed by concept 
testing relevant to future Navy needs. Unlike other Navy range 
complexes, training and testing in the MITT Study Area is more episodic 
as transiting strike groups or individual units travel through on the 
way to and from the Western Pacific, or forward deployed assets 
temporarily travel to the MITT Study Area for individual or group 
activities. This section analyzes a maximum number of activities that 
could occur each year and then a maximum total of activities that could 
occur over seven years. One activity, Torpedo (Explosive) Testing, does 
not occur every year, but the maximum times it could occur over one 
year and seven years was analyzed.
    The training and testing activities that the Navy proposes to 
conduct in the MITT Study Area are summarized in Table 3. The table is 
organized according to primary mission areas and includes the activity 
name, associated stressors, description of the activity, sound source 
bin, the locations of those activities in the MITT Study Area, and the 
number of activities. For further information regarding the primary 
platform used (e.g., ship or aircraft type) see Appendix A (Training 
and Testing Activities Descriptions) of the 2020 MITT FSEIS/OEIS.

                      Table 3--Training and Testing Activities Analyzed Annually and for a Seven-Year Period in the MITT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                      Annual     7-Year
   Stressor category          Activity              Description        Typical duration of     Source bin 1          Location       number of  number of
                                                                              event                                                   events     events
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                      Major Training Event--Large Integrated Anti-Submarine Warfare Training (ASW)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic..............  Joint Multi-Strike   Typically a 10-day Joint  10 days............  ASW2, ASW3, ASW4,   Study Area; MIRC..          1          7
                         Group Exercise.      exercise, in which up                          ASW5, HF1, MF1,
                                              to three carrier strike                        MF11, MF3, MF4,
                                              groups would conduct                           MF5, MF12, TORP1.
                                              training exercises
                                              simultaneously.
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 46308]]

 
                                                       Major Training Event--Medium Integrated ASW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic..............  Joint Expeditionary  Typically a 10-day        10 days............  ASW2, ASW3, MF1,    Study Area; Apra            1          7
                         Exercise.            exercise that could                            MF4, MF5, MF12.     Harbor.
                                              include a Carrier
                                              Strike Group and
                                              Expeditionary Strike
                                              Group, Marine
                                              Expeditionary Units,
                                              Army Infantry Units,
                                              and Air Force aircraft
                                              together in a joint
                                              environment that
                                              includes planning and
                                              execution efforts as
                                              well as military
                                              training activities at
                                              sea, in the air, and
                                              ashore.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Medium Coordinated ASW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic..............  Marine Air Ground    Typically a 10-day        10 days............  ASW3, MF1, MF4,     Study Area to               4         28
                         Task Force           exercise that conducts                         MF12.               nearshore; MIRC;
                         Exercise             over the horizon, ship                                             Tinian; Guam;
                         (Amphibious)--Batt   to objective maneuver                                              Rota; Saipan;
                         alion.               for the elements of the                                            Farallon De
                                              Expeditionary Strike                                               Medinilla.
                                              Group and the
                                              Amphibious Marine Air
                                              Ground Task Force. The
                                              exercise utilizes all
                                              elements of the Marine
                                              Air Ground Task Force
                                              (Amphibious),
                                              conducting training
                                              activities ashore with
                                              logistic support of the
                                              Expeditionary Strike
                                              Group and conducting
                                              amphibious landings.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                           ASW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic..............  Tracking Exercise--  Helicopter crews search   2-4 hours..........  MF4, MF5..........  Study Area >3 NM           10         70
                         Helicopter           for, detect, and track                                             from land;
                         (TRACKEX--Helo).     submarines.                                                        Transit Corridor.
Acoustic..............  Torpedo Exercise--   Helicopter crews search   2-5 hours..........  MF4, MF5, TORP1...  Study Area >3 NM            6         42
                         Helicopter           for, detect, and track                                             from land.
                         (TORPEX--Helo).      submarines. Recoverable
                                              air launched torpedoes
                                              are employed against
                                              submarine targets.
Acoustic..............  Tracking Exercise--  Maritime patrol aircraft  2-8 hours..........  MF5...............  Study Area >3 NM           36        252
                         Maritime Patrol      crews search for,                                                  from land.
                         Aircraft (TRACKEX--  detect, and track
                         Maritime Patrol      submarines.
                         Aircraft).
Acoustic..............  Torpedo Exercise--   Maritime patrol aircraft  2-8 hours..........  MF5, TORP1........  Study Area >3 NM            6         42
                         Maritime Patrol      crews search for,                                                  from land.
                         Aircraft (TORPEX--   detect, and track
                         Maritime Patrol      submarines. Recoverable
                         Aircraft).           air launched torpedoes
                                              are employed against
                                              submarine targets.
Acoustic..............  Tracking Exercise -  Surface ship crews        2-4 hours..........  ASW1, ASW3, MF1,    Study Area >3 NM           91        637
                         Surface (TRACKEX--   search for, detect, and                        MF11, MF12.         from land*.
                         Surface).            track submarines.
Acoustic..............  Torpedo Exercise--   Surface ship crews        2-5 hours..........  ASW3, MF1, MF5,     Study Area >3 NM            6         42
                         Surface (TORPEX--    search for, detect, and                        TORP1.              from land.
                         Surface).            track submarines.
                                              Exercise torpedoes are
                                              used during this event.
Acoustic..............  Tracking Exercise--  Submarine crews search    8 hours............  ASW4, HF1, HF3,     Study Area >3 NM            4         28
                         Submarine            for, detect, and track                         MF3.                from land;
                         (TRACKEX--Sub).      submarines.                                                        Transit Corridor.
Acoustic..............  Torpedo Exercise--   Submarine crews search    8 hours............  ASW4, HF1, MF3,     Study Area >3 NM            9         63
                         Submarine (TORPEX--  for, detect, and track                         TORP2.              from land.
                         Sub).                submarines. Recoverable
                                              exercise torpedoes are
                                              used during this event.
Acoustic..............  Small Combined       Typically, a 5-day        5 days.............  ASW2, ASW3, ASW4,   Study Area >3 NM           38         56
                         Coordinated ASW      exercise with multiple                         HF1, MF1, MF3,      from land*.
                         exercise (Multi-     ships, aircraft and                            MF4, MF5, MF11,
                         Sail/GUAMEX).        submarines integrating                         MF12.
                                              the use of their
                                              sensors, including
                                              sonobuoys, to search,
                                              detect, and track
                                              threat submarines.
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 46309]]

 
                                                                      Mine Warfare
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic..............  Civilian Port        Maritime security         Multiple days......  HF4, SAS2.........  MIRC, Mariana               1          7
                         Defense.             personnel train to                                                 littorals, Inner
                                              protect civilian ports                                             and Outer Apra
                                              and harbors against                                                Harbor.
                                              enemy efforts to
                                              interfere with access
                                              to those ports.
Explosive.............  Mine                 Ship, small boat, and     1-4 hours..........  E4................  Study Area,                 4         28
                         Neutralization--Re   helicopter crews locate                                            Mariana
                         motely Operated      and disable mines using                                            littorals, and
                         Vehicle Sonar (ASQ-  remotely operated                                                  Outer Apra Harbor.
                         235 [AQS-20], SLQ-   underwater vehicles.
                         48).
Acoustic..............  Mine Countermeasure  Ship crews detect,        1-4 hours..........  HF4...............  Study Area, Apra            4         28
                         Exercise--Surface    locate, identify, and                                              Harbor.
                         Ship Sonar (SQQ-     avoid mines while
                         32, MCM).            navigating restricted
                                              areas or channels, such
                                              as while entering or
                                              leaving port.
Acoustic..............  Mine Countermeasure  Surface ship crews        1-4 hours..........  HF4...............  Study Area, Apra            4         28
                         Exercise--Towed      detect and avoid mines                                             Harbor.
                         Sonar (AQS-20).      while navigating
                                              restricted areas or
                                              channels using towed
                                              active sonar systems.
Explosive.............  Mine                 Personnel disable threat  Up to 4 hours......  E5, E6............  Agat Bay site,             20        140
                         Neutralization--Ex   mines using explosive                                              Piti, and Outer
                         plosive Ordnance     charges.                                                           Apra Harbor.
                         Disposal.
Acoustic..............  Submarine Mine       Submarine crews practice  Varies.............  HF1...............  Study Area,                 1          7
                         Exercise.            detecting mines in a                                               Mariana
                                              designated area.                                                   Littorals, Inner/
                                                                                                                 Outer Apra Harbor.
Acoustic..............  Surface Ship Object  Ship crews detect and     1-4 hours..........  MF1K..............  Study Area........          6         42
                         Detection.           avoid mines while
                                              navigating restricted
                                              areas or channels using
                                              active sonar.
Explosive.............  Underwater           Navy divers conduct       Varies.............  E5, E6............  Agat Bay site,             45        315
                         Demolition           various levels of                                                  Piti, and Outer
                         Qualification/       training and                                                       Apra Harbor.
                         Certification.       certification in
                                              placing underwater
                                              demolition charges.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Surface Warfare (SUW)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Explosive.............  Bombing Exercise     Fixed-wing aircrews       1 hour.............  E9, E10, E12......  Study Area,                37        259
                         (Air-to-Surface).    deliver bombs against                                              Special Use
                                              stationary surface                                                 Airspace.
                                              targets.
Explosive.............  Gunnery Exercise     Fixed-wing and            1 hour.............  E1, E2............  Study Area >12 NM         120        840
                         (GUNEX) (Air-to-     helicopter aircrews                                                from land,
                         Surface)--Medium-    fire medium-caliber                                                Special Use
                         caliber.             guns at surface targets.                                           Airspace.
Explosive.............  GUNEX (Surface-to-   Small boat crews fire     1 hour.............  E2................  Study Area >12 NM          20        140
                         Surface) Boat--      medium-caliber guns at                                             from land,
                         Medium-caliber.      surface targets.                                                   Special Use
                                                                                                                 Airspace.
Explosive.............  GUNEX (Surface-to-   Surface ship crews fire   Up to 3 hours......  E5................  Study Area >12 NM         255      1,785
                         Surface) Ship--      large-caliber guns at                                              from land,
                         Large-caliber.       surface targets.                                                   Special Use
                                                                                                                 Airspace.
Explosive.............  GUNEX (Surface-to-   Surface ship crews fire   2-3 hours..........  E1................  Study Area >12 NM         234      1,638
                         Surface) Ship--      medium and small-                                                  from land,
                         Small- and Medium-   caliber guns at surface                                            Special Use
                         caliber.             targets.                                                           Airspace.
Explosive.............  Maritime Security    Helicopter, surface       Up to 3 hours......  E2................  Study Area; MIRC..         40        280
                         Operations.          ship, and small boat
                                              crews conduct a suite
                                              of maritime security
                                              operations at sea, to
                                              include visit, board,
                                              search and seizure,
                                              maritime interdiction
                                              operations, force
                                              protection, and anti-
                                              piracy operations.
Explosive.............  Missile Exercise     Fixed-wing and            2 hours............  E6, E8, E10.......  Study Area >12 NM          10         70
                         (Air-to-Surface)     helicopter aircrews                                                from land,
                         (MISSILEX [A-S]).    fire air-to-surface                                                Special Use
                                              missiles at surface                                                Airspace.
                                              targets.
Explosive.............  Missile Exercise     Helicopter aircrews fire  1 hour.............  E3................  Study Area >12 NM         110        770
                         (Air-to-Surface)--   both precision-guided                                              from land,
                         Rocket (MISSILEX     and unguided rockets at                                            Special Use
                         [A-S]--Rocket).      surface targets.                                                   Airspace.

[[Page 46310]]

 
Explosive.............  Missile Exercise     Surface ship crews        2-5 hours..........  E6, E10...........  Study Area >50 NM          28        196
                         (Surface-to-         defend against surface                                             from land,
                         Surface).            threats (ships or small                                            Special Use
                        (MISSILEX [S-S])...   boats) and engage them                                             Airspace.
                                              with missiles.
Explosive.............  Sinking Exercise...  Aircraft, ship, and       4-8 hours, possibly  E5, E8, E10, E11,   Study Area >50 NM           1          7
                                              submarine crews           over 1-2 days.       E12, TORP2.         from land and
                                              deliberately sink a                                                >1,000 fathoms
                                              seaborne target,                                                   depth.
                                              usually a
                                              decommissioned ship
                                              made environmentally
                                              safe for sinking
                                              according to U.S.
                                              Environmental
                                              Protection Agency
                                              standards, with a
                                              variety of ordnance.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Other Training Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic..............  Submarine            Submarine crews operate   Up to 2 hours......  HF1, MF3..........  Study Area, Apra            8         56
                         Navigation.          sonar for navigation                                               Harbor, and
                                              and detection while                                                Mariana littorals.
                                              transiting into and out
                                              of port during reduced
                                              visibility.
Acoustic..............  Submarine Sonar      Maintenance of submarine  Up to 1 hour.......  MF3...............  Study Area; Apra           86        602
                         Maintenance.         sonar and other system                                             Harbor and
                                              checks are conducted                                               Mariana littorals.
                                              pierside or at sea.
Acoustic..............  Surface Ship Sonar   Maintenance of surface    Up to 4 hours......  MF1...............  Study Area; Apra           44        308
                         Maintenance.         ship sonar and other                                               Harbor and
                                              system checks are                                                  Mariana littorals.
                                              conducted pierside or
                                              at sea.
Acoustic..............  Unmanned Underwater  Units conduct training    Up to 24 hours.....  FLS2, M3, SAS2,     MIRC; Apra Harbor          64        448
                         Vehicle Training.    with unmanned                                  SAS4.               and Mariana
                                              underwater vehicles                                                littorals.
                                              from a variety of
                                              platforms, including
                                              surface ships, small
                                              boats, and submarines.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Testing Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
          ASW
Acoustic; Explosive...  Anti-Submarine       The test evaluates the    8 hours............  ASW2, ASW5, E1,     Study Area >3 NM           26        182
                         Warfare Tracking     sensors and systems                            E3, MF5, MF6.       from land.
                         Test--Maritime       used by maritime patrol
                         Patrol Aircraft      aircraft to detect and
                         (Sonobuoys).         track submarines and to
                                              ensure that aircraft
                                              systems used to deploy
                                              the tracking systems
                                              perform to
                                              specifications and meet
                                              operational
                                              requirements.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic..............  Anti-Submarine       This event is similar to  2-6 flight hours...  MF5, TORP1........  Study Area >3 NM           20        140
                         Warfare Torpedo      the training event                                                 from land.
                         Test.                torpedo exercise. Test
                                              evaluates anti-
                                              submarine warfare
                                              systems onboard rotary-
                                              wing and fixed-wing
                                              aircraft and the
                                              ability to search for,
                                              detect, classify,
                                              localize, track, and
                                              attack a submarine or
                                              similar target.
Acoustic..............  Anti-Submarine       Ships and their           1-2 weeks, with 4-8  ASW1, ASW2, ASW3,   Mariana Island            100        700
                         Warfare Mission      supporting platforms      hours of active      ASW5, MF12, MF4,    Range Complex.
                         Package Testing.     (e.g., helicopters and    sonar use with       MF5, TORP1.
                                              unmanned aerial           intervals of non-
                                              systems) detect,          activity in
                                              localize, and prosecute   between.
                                              submarines.
Acoustic..............  At-Sea Sonar         At-sea testing to ensure  From 4 hours to 11   HF1, HF6, M3, MF3,  Study Area........          7         49
                         Testing.             systems are fully         days.                MF9.
                                              functional in an open
                                              ocean environment.
Acoustic; Explosive...  Torpedo (Explosive)  Air, surface, or          1-2 days during      ASW3, HF1, HF6,     Mariana Island              3          9
                         Testing.             submarine crews employ    daylight hours.      MF1, MF3, MF4,      Range Complex.
                                              explosive and non-                             MF5, MF6, TORP1,
                                              explosive torpedoes                            TORP2, E8, E11.
                                              against artificial
                                              targets.
Acoustic..............  Torpedo (Non-        Air, surface, or          Up to 2 weeks......  ASW3, ASW4, HF1,    Mariana Island              7         49
                         explosive) Testing.  submarine crews employ                         HF6, LF4, MF1,      Range Complex.
                                              non-explosive torpedoes                        MF3, MF4, MF5,
                                              against submarines or                          MF6, TORP1,
                                              surface vessels.                               TORP2, TORP3.
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 46311]]

 
                                                                      Mine Warfare
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic; Explosive...  Mine Countermeasure  Air, surface, and         1-10 days, with      HF4, E4...........  MIRC; nearshore             3         21
                         and Neutralization   subsurface vessels        intermittent use                         and littorals.
                         Testing.             neutralize threat mines   of countermeasure/
                                              and mine-like objects.    neutralization
                                                                        systems during
                                                                        this period.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Surface Warfare
--------------------------------------------------------------------------------------------------------------------------------------------------------
Explosive.............  Air to Surface       Fixed-wing and            2 hours............  E10...............  Study Area >50 NM           4         28
                         Missile Test.        helicopter aircrews                                                from land.
                                              fire air-to-surface
                                              missiles at surface
                                              targets.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Vessel Evaluation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acoustic..............  Undersea Warfare     Ships demonstrate         Up to 10 days......  HF4, MF1, MF4,      MIRC..............          1          7
                         Testing.             capability of                                  MF5, TORP1.
                                              countermeasure systems
                                              and underwater
                                              surveillance, weapons
                                              engagement, and
                                              communications systems.
                                              This tests ships'
                                              ability to detect,
                                              track, and engage
                                              undersea targets.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Additional activities utilizing sources not listed in the Major Training Event and coordinated exercise bins above may occur during these exercises.
  All acoustic sources which may be used during training and testing activities have been accounted for in the modeling and analysis presented in this
  application and in the 2020 MITT FSEIS/OEIS.
* Includes limited occurrence within the Marpi Reef Geographic Mitigation Area and a portion of Chalan Kanoa Reef Geographic Mitigation Area outside of
  3 nmi from land (see Figures 1 and 2).

Summary of Acoustic and Explosive Sources Analyzed for Training and 
Testing

    Tables 4 and 5 show the acoustic and explosive source classes, 
bins, and quantities used in either hours or counts associated with the 
Navy's training and testing activities over a seven-year period in the 
MITT Study Area that were analyzed in the Navy's rulemaking/LOA 
application. Table 4 describes the acoustic source classes (i.e., low-
frequency (LF), mid-frequency (MF), and high-frequency (HF)) that could 
occur over seven years under the planned training and testing 
activities. Acoustic source bin use in the planned activities will vary 
annually. The seven-year totals for the planned training and testing 
activities take into account that annual variability.

   Table 4--Acoustic Source Classes Analyzed and Number Used for a Seven-Year Period for Training and Testing
                                        activities in the MITT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                                         7-year
      Source class category                Bin             Description           Unit         Annual     total
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF): Sources that   LF4...............  LF sources equal to  H.............          1          7
 produce signals less than 1 kHz.                       180 dB and up to
                                                        200 dB.
                                   LF5...............  LF sources less      H.............         10         65
                                                        than 180 dB.
Mid-Frequency (MF): Tactical and   MF1...............  Hull-mounted         H.............      1,818     12,725
 non-tactical sources that                              surface ship
 produce signals between 1 and 10                       sonars (e.g., AN/
 kHz.                                                   SQS-53C and AN/SQS-
                                                        60).
                                   MF1K..............  Kingfisher mode      H.............          3         21
                                                        associated with
                                                        MF1 sonars.
                                   MF3...............  Hull-mounted         H.............        227      1,586
                                                        submarine sonars
                                                        (e.g., AN/BQQ-10).
                                   MF4...............  Helicopter-deployed  H.............        185      1,289
                                                        dipping sonars
                                                        (e.g., AN/AQS-22).
                                   MF5...............  Active acoustic      C.............      2,094     14,623
                                                        sonobuoys (e.g.,
                                                        DICASS).
                                   MF6...............  Active underwater    C.............         74        458
                                                        sound signal
                                                        devices (e.g., MK
                                                        84 SUS).
                                   MF9...............  Active sources       H.............         29        202
                                                        (equal to 180 dB
                                                        and up to.
                                                       200 dB) not
                                                        otherwise binned.
                                   MF11..............  Hull-mounted         H.............        304      2.128
                                                        surface ship
                                                        sonars with an
                                                        active duty cycle
                                                        greater than 80%.
                                   MF12..............  Towed array surface  H.............        616      4,320
                                                        ship sonars with
                                                        an active duty
                                                        cycle greater than
                                                        80%.
High-Frequency (HF): Tactical and  HF1...............  Hull-mounted         H.............         73        497
 non-tactical sources that                              submarine sonars
 produce signals between 10 and                         (e.g., AN/BQQ-10).
 100 kHz.
                                   HF3...............  Other hull-mounted   H.............          4         28
                                                        submarine sonars
                                                        (classified).

[[Page 46312]]

 
                                   HF4...............  Mine detection,      H.............      1,472     10,304
                                                        classification,
                                                        and neutralization
                                                        sonar (e.g., AN/
                                                        SQS-20).
                                   HF6...............  Active sources       H.............        309      2,128
                                                        (equal to 180 dB
                                                        and up to 200 dB)
                                                        not otherwise
                                                        binned.
Anti-Submarine Warfare (ASW):      ASW1..............  MF systems           H.............        192      1,360
 Tactical sources (e.g., active                         operating above
 sonobuoys and acoustic                                 200 dB.
 countermeasures systems) used
 during ASW training and testing
 activities.
                                   ASW2..............  MF Multistatic       C.............        554      3,878
                                                        Active Coherent
                                                        sonobuoy (e.g., AN/
                                                        SSQ-125).
                                   ASW3..............  MF towed active      H.............      3,124     21,863
                                                        acoustic
                                                        countermeasure
                                                        systems (e.g., AN/
                                                        SLQ-25).
                                   ASW4..............  MF expendable        C.............        332      2,324
                                                        active acoustic
                                                        device
                                                        countermeasures
                                                        (e.g., MK 3).
                                   ASW5..............  MF sonobuoys with    H.............         50        350
                                                        high duty cycles.
Torpedoes (TORP): Source classes   TORP1.............  Lightweight torpedo  C.............         71        485
 associated with the active                             (e.g., MK 46, MK
 acoustic signals produced by                           54, or Anti-
 torpedoes.                                             Torpedo Torpedo).
                                   TORP2.............  Heavyweight torpedo  C.............         62        398
                                                        (e.g., MK 48).
                                   TORP3.............  Heavyweight torpedo  C.............          6         42
                                                        test (e.g., MK 48).
Forward Looking Sonar (FLS):       FLS2..............  HF sources with      H.............          4         28
 Forward or upward looking object                       short pulse
 avoidance sonars used for ship                         lengths, narrow
 navigation and safety.                                 beam widths, and
                                                        focused beam
                                                        patterns.
Acoustic Modems (M): Systems used  M3................  MF acoustic modems   H.............         31        216
 to transmit data through the                           (greater than 190
 water.                                                 dB).
Synthetic Aperture Sonars (SAS):   SAS2..............  HF SAS systems.....  H.............        449      3,140
 Sonars in which active acoustic
 signals are post-processed to
 form high-resolution images of
 the seafloor.
                                   SAS4..............  MF to HF broadband   H.............          6         42
                                                        mine
                                                        countermeasure
                                                        sonar.
----------------------------------------------------------------------------------------------------------------
Notes: H= hours; C = count.

    Table 5 describes the number of in-water explosives that could be 
used in any year under the planned training and testing activities. 
Under the planned activities, bin use will vary annually, and the 
seven-year totals for the planned training and testing activities take 
into account that annual variability.

Table 5--Explosive Source Bins Analyzed and Number Used Annually and for
 a Seven-Year Period for Training and Testing Activities Within the MITT
                               Study Area
------------------------------------------------------------------------
                  Net explosive  Example Explosive               7-year
      Bin          weight (lb)         Source         Annual     total
------------------------------------------------------------------------
E1.............        0.1-0.25  Medium-caliber           768      5,376
                                  projectiles.
E2.............       >0.25-0.5  Anti-swimmer             400      2,800
                                  grenade.
E3.............        >0.5-2.5  57 mm projectile.        683      4,591
E4.............          >2.5-5  Mine                      44        308
                                  neutralization
                                  charge.
E5.............           >5-10  5 in projectiles.      1,221      8,547
E6.............          >10-20  15 lb shaped              29        203
                                  charge.
E8.............         >60-100  250 lb bomb;             134        932
                                  Light weight
                                  torpedo.
E9.............        >100-250  500 lb bomb......        110        770
E10............        >250-500  1,000 lb bomb....         78        546
E11............        >500-650  Heavy weight               5         17
                                  torpedo.
E12............      >650-1,000  2,000 lb bomb....         48        336
------------------------------------------------------------------------
Notes: (1) net explosive weight refers to the equivalent amount of TNT.
  The actual weight of a munition may be larger due to other components.
  (2) in = inch(es), lb = pound(s), ft = feet.

Vessel Movement

    The only areas with projected high concentrations of Navy vessel 
movement will be within Apra Harbor Guam and the coastal approaches to 
and from Apra Harbor. Some amphibious training events use Tinian as a 
landing area so amphibious ships could occur in the offshore waters off 
that island. Most other activities are spread throughout the greater 
MITT Study Area with a high degree of spatial and temporal separation 
between activities. Additional detail on vessel movement was provided 
in our Federal Register notice of proposed rulemaking (85 FR 5782; 
January 31, 2020); please see that notice of proposed rulemaking or the

[[Page 46313]]

Navy's application for more information.
    The Navy tabulated annual at-sea vessel steaming days for training 
and testing activities projected for the MITT Study Area. Across all 
warfare areas and activities, 493 days of Navy at-sea time will occur 
annually for training and testing activities in the MITT Study Area 
(Table 6). Amphibious Warfare activities account for 48 percent of 
total surface ship days, MTEs account for 38 percent, ASW activities 
account for 8 percent, and Air Warfare, ASW, and Other activities 
(sonar maintenance, anchoring) account for 2 percent each (Table 6). In 
comparison to the Hawaii-Southern California Training and Testing 
(HSTT) Study Area, the estimated number of at-sea annual days for 
training and testing activities in the MITT Study Area is approximately 
ten times less than in the HSTT Study Area over the same time period.

                        Table 6--Annual Navy Surface Ship Days Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                    Percent by    Annual days by    Percent by
                   MITT events                      Annual days        event       warfare area    warfare area
----------------------------------------------------------------------------------------------------------------
Air Warfare.....................................  ..............  ..............               9             1.9
    GUNNEX (Lg).................................               2             0.3
    GUNNEX (Sm).................................               3             0.6
    MISSILEX....................................               5             0.9
Amphibious Warfare..............................  ..............  ..............             299            60.7
    Fire Support (Land Target)..................               5             1.0
    Amphibious Rehearsal........................             144            29.2
    Amphibious Assault..........................              14             2.8
    Amphibious Raid.............................               3             0.6
    Marine Air Ground Task Force Exercise.......              40             8.1
    Non-Combatant Evacuation Op.................              67            13.5
    Humanitarian Assist/Disaster Relief Op......               7             1.4
    Special Purpose.............................              20             4.1
    Marine Air Ground Task Force Exercise.......
Surface Warfare.................................  ..............  ..............              41             8.4
    MISSILEX....................................               2             0.4
    GUNNEX (Lg).................................              14             2.8
    GUNNEX (Med)................................              10             2.0
    GUNNEX (Sm).................................               6             1.3
    SINKEX......................................               7             1.4
    Maritime Security Op........................               3             0.5
Anti-Submarine Warfare..........................  ..............  ..............               8             1.6
    Tracking Exercise...........................               8             1.5
    Torpedo Exercise............................               1             0.1
Major Training Exercises........................  ..............  ..............             125            24.5
    Joint Expeditionary Exercise................              63            12.9
    Joint Multi-Strike Group Exercise...........              62            12.5
Other...........................................  ..............  ..............              10             2.1
    Surface Ship Sonar Maintenance..............               7            1.5%
    Precision Anchoring.........................               3            0.6%
                                                 ---------------------------------------------------------------
        Total...................................             493
----------------------------------------------------------------------------------------------------------------

    Additional details on Navy at-sea vessel movement are provided in 
the 2020 MITT FSEIS/OEIS.

Standard Operating Procedures

    For training and testing to be effective, personnel must be able to 
safely use their sensors and weapon systems as they are intended to be 
used in military missions and combat operations and to their optimum 
capabilities. While standard operating procedures are designed for the 
safety of personnel and equipment and to ensure the success of training 
and testing activities, their implementation often yields additional 
benefits on environmental, socioeconomic, public health and safety, and 
cultural resources.
    Because standard operating procedures are essential to safety and 
mission success, the Navy considers them to be part of the planned 
Specified Activities, and has included them in the environmental 
analysis. Additional details on standard operating procedures were 
provided in our Federal Register notice of proposed rulemaking (85 FR 
5782; January 31, 2020); please see that notice of proposed rulemaking 
or the Navy's application for more information.

Comments and Responses

    We published the proposed rule in the Federal Register on January 
31, 2020 (85 FR 5782), with a 45-day comment period. With that proposed 
rule, we requested public input on our analyses, our preliminary 
findings, and the proposed regulations, and requested that interested 
persons submit relevant information and comments. During the 45-day 
comment period, we received 16 comment letters in total. Of this total, 
one submission was from another Federal agency, one was from the Marine 
Mammal Commission, three letters were from organizations or individuals 
acting in an official capacity (e.g., non-governmental organizations 
(NGOs), and 11 submissions were from private citizens. NMFS has 
reviewed and considered all public comments received on the proposed 
rule and issuance of the LOA. General comments that did not provide 
information pertinent to NMFS' decisions have been noted, but are not 
addressed further. All substantive comments and our responses are 
described below. We provide no response to specific comments that 
addressed species or statutes not relevant to the rulemaking under 
section 101(a)(5)(A) of the MMPA (e.g., comments related to sea 
turtles). We organize our comment responses by major categories.

[[Page 46314]]

General Comments

    Comment 1: The Navy must be required to submit a Habitat 
Conservation Plan that will ensure the well being of those mammals to 
the best extent possible.
    Response: A Habitat Conservation Plan (HCP) is a planning document 
for non-Federal agencies and persons to obtain an ESA incidental take 
permit under section 10(a)(1)(B) of the Endangered Species Act (ESA). 
The Navy is a Federal agency that consulted with NMFS under section 7 
of the ESA, and therefore obtaining a separate ESA incidental take 
permit is not required. The Navy will comply with the Reasonable and 
Prudent Measures and Terms and Conditions that are part of their 
Incidental Take Statement, which was issued as part of the consultation 
process under section 7 of the ESA.

Impact Analysis and Thresholds

    Comment 2: A commenter recommended that NMFS clarify whether and 
how the Navy incorporated uncertainty in its density estimates for its 
animat modeling specific to MITT and if uncertainty was not 
incorporated, re-estimate the numbers of marine mammal takes based on 
the uncertainty inherent in the density estimates provided in 
Department of the Navy (2018b).
    Response: Uncertainty was incorporated into the density estimates 
used for modeling and estimating take for NMFS' rule. The commenter is 
referred to the technical report titled ``Quantifying Acoustic Impacts 
on Marine Mammals and Sea Turtles: Methods and Analytical Approach for 
Phase III Training and Testing'' (U.S. Department of the Navy, 2018) 
for clarification on the consideration of uncertainty in density 
estimates. See specifically Section 4.2 (Marine Species Distribution 
Builder) of the 2020 MITT FSEIS/OEIS where details are provided on how 
statistical uncertainty surrounding density estimates was incorporated 
into the modeling for the MITT Study Area, as has been done for all 
other recent NMFS and Navy analyses of training and testing at sea. To 
the Commenters more specific question, as with the 2018 HSTT final 
rule, a lognormal distribution was used in the density regression 
model. Uncertainty was incorporated into the take estimation through 
the density estimates and it is not necessary to re-estimate the take 
numbers for marine mammals.
    Comment 3: A Commenter stated that NMFS has largely followed the 
Navy in revising its hearing loss thresholds to reflect certain new 
data and modeling approaches. The Commenter suggested they have 
previously advised that the criteria that NMFS produced to estimate 
temporary and permanent threshold shift in marine mammals are erroneous 
and non-conservative. According to the Commenter, Wright (2015) has 
identified several statistical and numerical faults in NMFS' approach, 
such as pseudo-replication and inconsistent treatment of data, that 
tend to bias the criteria towards an underestimation of effects. The 
Commenter stated that similar and additional issues were raised by a 
dozen scientists during the public comment period on the draft criteria 
held by NMFS. The Commenter asserts that the issue is NMFS' broad 
extrapolation from a small number of individual animals, mostly 
bottlenose dolphins, without taking account of what Racca et al. 
(2015b) have succinctly characterized as a ``non-linear accumulation of 
uncertainty.'' The Commenter asserts that NMFS failed to address the 
basic errors identified by these and other experts, nor did it perform 
a sensitivity analysis to understand the potential magnitude of those 
errors. The Commenter suggests that NMFS should not rely exclusively on 
its auditory guidance in determining ``Level A'' take, but should, at 
minimum, produce a conservative upper bound such as by retaining the 
180 dB threshold, or by performing a sensitivity analysis.
    Response: The Acoustic Technical Guidance updates the historical 
180 dB rms injury threshold, which was based on professional judgement 
(i.e., no data were available on the effects of noise on marine mammal 
hearing at the time this original threshold was derived). NMFS 
disagrees with any suggestion that the use of the Acoustic Technical 
Guidance provides erroneous results. The 180 dB rms threshold is 
plainly outdated, as the best available science indicates that rms SPL 
is not even an appropriate metric by which to gauge potential auditory 
injury. Further, NMFS disagrees with the suggestion that NMFS should 
not rely exclusively on its Technical Guidance in determining take by 
Level A harassment and should instead also produce an upper bound 
(either by retaining the 180-dB threshold or performing a sensitivity 
analysis). The Acoustic Technical Guidance represents the best 
available science and provides thresholds and weighting functions that 
allow us to predict when marine mammals are likely to incur permanent 
threshold shift (PTS). As described in the Estimated Take of Marine 
Mammals section, when the acoustic thresholds, the Navy model, and 
other inputs into the take calculation are considered, the authorized 
incidental takes represent the maximum number of instances in which 
marine mammals are reasonably expected to be taken, which is 
appropriate under the statute and there is no need or requirement for 
NMFS to authorize a larger number.
    Multiple studies from humans, terrestrial mammals, and marine 
mammals have demonstrated less temporary threshold shift (TTS) from 
intermittent exposures compared to continuous exposures with the same 
total energy because hearing is known to experience some recovery in 
between noise exposures, which means that the effects of intermittent 
noise sources such as tactical sonars are likely overestimated. Marine 
mammal TTS data have also shown that, for two exposures with equal 
energy, the longer duration exposure tends to produce a larger amount 
of TTS. Most marine mammal TTS data have been obtained using exposure 
durations of tens of seconds up to an hour, much longer than the 
durations of many tactical sources (much less the continuous time that 
a marine mammal in the field would be exposed consecutively to those 
levels), further suggesting that the use of these TTS data are likely 
to overestimate the effects of sonars with shorter duration signals.
    Regarding the suggestion of pseudoreplication and erroneous models, 
since marine mammal hearing and noise-induced hearing loss data are 
limited, both in the number of species and in the number of individuals 
available, attempts to minimize pseudoreplication would further reduce 
these already limited data sets. Specifically, with marine mammal 
behaviorally derived temporary threshold shift studies, behaviorally 
derived data are only available for two mid-frequency cetacean species 
(bottlenose dolphin, beluga) and two phocids (in-water) pinniped 
species (harbor seal and northern elephant seal), with otariid (in-
water) pinnipeds and high-frequency cetaceans only having behaviorally-
derived data from one species. Arguments from Wright (2015) regarding 
pseudoreplication within the TTS data are therefore largely irrelevant 
in a practical sense because there are so few data. Multiple data 
points were not included for the same individual at a single frequency. 
If multiple data existed at one frequency, the lowest TTS onset was 
always used. There is only a single frequency where TTS onset data 
exist for two individuals of the same species: 3 kHz for bottlenose 
dolphins. Their TTS (unweighted) onset values

[[Page 46315]]

were 193 and 194 dB re 1 [mu]Pa2s. Thus, NMFS believes that the current 
approach makes the best use of the given data. Appropriate means of 
reducing pseudoreplication may be considered in the future, if more 
data become available. Many other comments from Wright (2015) and the 
comments from Racca et al. (2015b) appear to be erroneously based on 
the idea that the shapes of the auditory weighting functions and TTS/
PTS exposure thresholds are directly related to the audiograms; i.e., 
that changes to the composite audiograms would directly influence the 
TTS/PTS exposure functions (e.g., Wright (2015) describes weighting 
functions as ``effectively the mirror image of an audiogram'' (p. 2) 
and states, ``The underlying goal was to estimate how much a sound 
level needs to be above hearing threshold to induce TTS.'' (p. 3)). 
Both statements are incorrect and suggest a fundamental 
misunderstanding of the criteria/threshold derivation. This would 
require a constant (frequency-independent) relationship between hearing 
threshold and TTS onset that is not reflected in the actual marine 
mammal TTS data. Attempts to create a ``cautionary'' outcome by 
artificially lowering the composite audiogram thresholds would not 
necessarily result in lower TTS/PTS exposure levels, since the exposure 
functions are to a large extent based on applying mathematical 
functions to fit the existing TTS data.
    Comment 4: A Commenter recommended that NMFS specify in the 
preamble to the final rule whether the data regarding behavioral 
audiograms (Branstetter et al. 2017, Kastelein et al. 2017b) and TTS 
(Kastelein et al. 2017a and c, Popov et al. 2017, Kastelein et al. 
2018a and 2019a and b) support the continued use of the current 
weighting functions and PTS and TTS thresholds.
    Response: Thus far, no new information has been published or 
otherwise conveyed that would fundamentally change the assessment of 
impacts or conclusions of this rule regarding current weighting 
functions and PTS and TTS thresholds. Furthermore, the recent peer-
reviewed updated marine mammal noise exposure criteria by Southall et 
al. (2019a) provide identical PTS and TTS thresholds to those provided 
in NMFS' Acoustic Technical Guidance. NMFS' Revised Technical Guidance 
for Assessing the Effects of Anthropogenic Sound on Marine Mammal 
Hearing (NMFS 2018) (Acoustic Technical Guidance), which was used in 
the assessment of effects for this rulemaking, compiled, interpreted, 
and synthesized the best available scientific information for noise-
induced hearing effects for marine mammals to derive updated thresholds 
for assessing the impacts of noise on marine mammal hearing, including 
the articles that the Commenter referenced that were published 
subsequent to the publication of the first version of the Acoustic 
Technical Guidance in 2016. The new data included in those articles are 
consistent with the thresholds and weighting functions included in the 
current version of the Acoustic Technical Guidance (NMFS, 2018). NMFS 
will continue to review and evaluate new relevant data as it becomes 
available and consider the impacts of those studies on the Acoustic 
Technical Guidance to determine what revisions/updates may be 
appropriate.
    Comment 5: Commenters recommended that NMFS refrain from using cut-
off distances in conjunction with the Bayesian Behavioral Response 
Functions (BRFs) and re-estimate the numbers of marine mammal takes 
based solely on the Bayesian BRFs as the use of cut-off distances could 
be perceived as an attempt to reduce the numbers of takes.
    Response: The consideration of proximity (cut-off distances) was 
part of the criteria developed in consultation between the Navy and 
NMFS, and is appropriate based on the best available science which 
shows that marine mammal responses to sound vary based on both sound 
level and distance. Therefore these cut-off distances were applied 
within the Navy's acoustic effects model. The derivation of the 
behavioral response functions and associated cut-off distances is 
provided in the 2017 technical report titled ``Criteria and Thresholds 
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)''. To 
account for non-applicable contextual factors, all available data on 
marine mammal reactions to actual Navy activities and other sound 
sources (or other large scale activities such as seismic surveys when 
information on proximity to sonar sources was not available for a given 
species group) were reviewed to find the farthest distance to which 
significant behavioral reactions were observed. These distances were 
rounded up to the nearest 5 or 10 km interval, and for moderate to 
large scale activities using multiple or louder sonar sources, these 
distances were greatly increased--doubled in most cases. The Navy's 
BRFs applied within these distances provide technically sound methods 
reflective of the best available science to estimate the impact and 
potential take for the actions analyzed within the 2020 MITT FSEIS/OEIS 
and included in these regulations. NMFS has independently assessed the 
Navy's behavioral harassment thresholds (i.e., their BRFs) and finds 
that they appropriately apply the best available science and it is not 
necessary to recalculate take estimates.
    The Commenters also specifically expressed concern that distance 
``cut-offs'' alleviate some of the exposures that would otherwise have 
been counted if the received level alone were considered. It is unclear 
why the Commenters find this inherently inappropriate, as this is what 
the data show. As noted previously, there are multiple studies 
illustrating that in situations where one would expect behavioral 
disturbance of a certain degree because of the received levels at which 
previous responses were observed, it has not occurred when the distance 
from the source was larger than the distance of the first observed 
response.
    Comment 6: Regarding the behavioral harassment thresholds for 
explosives, Commenters recommended that NMFS estimate and ultimately 
authorize takes of marine mammals by Level B harassment in the form of 
behavioral disturbance, as well as TTS, during all explosive 
activities, including those that involve single detonations.
    Response: The derivation of the explosive injury criteria is 
provided in the 2017 technical report titled ``Criteria and Thresholds 
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III),'' 
and NMFS has applied the general rule a commenter referenced to single 
explosives for years, i.e., that marine mammals are unlikely to respond 
to a single instantaneous detonation at received levels below the TTS 
threshold in a manner that would rise to the level of a take. Neither 
NMFS nor the Navy are aware of evidence to support the assertion that 
animals will have significant behavioral reactions (i.e., those that 
would rise to the level of a take) to temporally and spatially isolated 
explosions at received levels below the TTS threshold.
    Marine mammals may be exposed to isolated impulses in their natural 
environment (e.g., lightning). There is no evidence to support that 
animals have significant behavioral responses to temporally and 
spatially isolated impulses (such as military explosions) that may rise 
to the level of ``harassment'' under the MMPA for military readiness 
activities. Still, the analysis conservatively assumes that any modeled 
instance of temporally or spatially separated detonations occurring in 
a single 24-hour period would result in harassment under the

[[Page 46316]]

MMPA for military readiness activities. The Navy has been monitoring 
detonations since the 1990s and has not observed these types of 
reactions. To be clear, this monitoring has occurred under the 
monitoring plans developed specifically for shock trials, the 
detonations with the largest net explosive weight conducted by the 
Navy, and no shock trials are proposed in this study area.
    Further, to clarify, the current take estimate framework does not 
preclude the consideration of animals being behaviorally disturbed 
during single explosions as they are counted as ``taken by Level B 
harassment'' if they are exposed above the TTS threshold, which is only 
5 dB higher than the behavioral harassment threshold. We acknowledge in 
our analysis that individuals exposed above the TTS threshold may also 
be behaviorally disturbed and those potential impacts are considered in 
the negligible impact determination.
    Comment 7: A Commenter stated that the behavioral response 
functions rely on captive animal studies and the risk functions do not 
incorporate a number of relevant studies on wild marine mammals 
(specifically referencing a passive acoustic study on blue whales). The 
Commenter asserts it is not clear from the proposed rule, or from the 
Navy's recent technical report on acoustic ``criteria and thresholds,'' 
on which NMFS' approach here is based, exactly how each of the studies 
that NMFS employed was applied in the analysis, or how the functions 
were fitted to the data, but the available evidence on behavioral 
response raises serious concerns that the functions are not 
conservative for some species. For this reason and others, and given 
the obvious importance of this analysis for future acoustic impact 
analyses, the Commenter requests that NMFS make additional technical 
information available, including from any expert elicitation and peer 
review, and to re-open public comment on this issue.
    Response: We refer the Commenter to the Criteria and Thresholds for 
the U.S. Navy Acoustic and Explosive Effects Analysis (Phase III) 
Technical Report (U.S. Department of the Navy, 2017) for details on how 
the Navy accounted for the differences in captive and wild animals in 
the development of the behavioral response risk functions, which NMFS 
has evaluated and deemed appropriate to incorporate into the analysis 
in the rule. The appendices to this report detail the specific data 
points used to generate the behavioral response functions. Data points 
come from published data that is readily available and cited within the 
technical report, and NMFS disagrees that it is necessary to re-open 
public comment on this issue.
    The Navy uses the best available science in the analysis, which has 
been reviewed by external scientists and approved by NMFS. The Navy 
considered all data available at the time for the development of 
updated criteria and thresholds, and limiting the data to the small 
number of field studies would not provide enough data with which to 
develop the new risk functions. In addition, the Navy accounts for the 
fact that captive animals may be less sensitive, and the scale at which 
a moderate-to-severe response was considered to have occurred is 
different for captive animals than for wild animals, as the Navy 
understands those responses will be different. The new risk functions 
were developed in 2016, before several recent papers were published or 
the data were available. The Navy and NMFS continue to evaluate the 
information as new science is made available. The criteria have been 
rigorously vetted within the Navy community, among scientists during 
expert elicitation, and then reviewed by the public before being 
applied. It is unreasonable to revise and update the criteria and risk 
functions every time a new paper is published. NMFS concurs with the 
Navy's evaluation and conclusion that there is no new information that 
necessitates changing the acoustic thresholds at this time.
    These new papers provide additional information, and the Navy is 
considering them for updates to the criteria in the future, when the 
next round of updated criteria will be developed. Regarding 
consideration of research findings involving a passive acoustic study 
on blue whale vocalizations and behavior, the Navy considered multiple 
recent references, including but not limited to: Paniagua-Mendoza, 
2017; Lesage, 2017; DeRuiter, 2017; Mate, 2016; Lomac-MacNair, 2016; 
Friedlaender, 2016; Mate, 2015. Thus far, no new information has been 
published or otherwise conveyed that would fundamentally change the 
assessment of impacts or conclusions of this Supplemental EIS/OEIS. To 
be included in the BRF, data sets needed to relate known or estimable 
received levels to observations of individual or group behavior. Melcon 
et al. (2012) does not relate observations of individual/group behavior 
to known or estimable received levels at that individual/group. In 
Melcon et al. (2012), received levels at the HARP buoy averaged over 
many hours are related to probabilities of D-calls, but the received 
level at the blue whale individuals/group are unknown.
    Comment 8: A Commenter commented that dipping sonar, like hull-
mounted sonar, appears to be a significant predictor of deep-dive rates 
in beaked whales, with the dive rate falling significantly (e.g., to 35 
percent of that individual's control rate) during sonar exposure, and 
likewise appears associated with habitat abandonment. According to the 
Commenter, the data sources used to produce the Navy's behavioral 
response functions (BRF) concern hull-mounted sonar, an R/V-deployed 
sonar playback, or an in-pool source. The Navy's generic behavioral 
response function for beaked whales does not incorporate their 
heightened response to these sources, although such a response would be 
presumed to shift its risk function ``leftward.'' Nor do the response 
functions for other species account for this difference, although 
unpredictability is known to exacerbate stress response in a diversity 
of mammalian species and should conservatively be assumed, in this 
case, to lead to a heightened response in marine mammal species other 
than beaked whales.
    Response: In consultation with NMFS, the Navy relied upon the best 
science that was available to develop the behavioral response 
functions. The current beaked whale BRF acknowledges and incorporates 
the increased sensitivity observed in beaked whales during both 
behavioral response studies and during actual Navy training events, as 
well as the fact that dipping sonar can have greater effects than some 
other sources with the same source level. Specifically, the distance 
cut-off for beaked whales is 50 km, larger than any other group. 
Moreover, although dipping sonar has a significantly lower source level 
than hull-mounted sonar, it is included in the category of sources with 
larger distance cut-offs, specifically in acknowledgement of its 
unpredictability and association with observed effects. This means that 
``takes'' are reflected at lower received levels that would have been 
excluded because of the distance for other source types.
    An article referenced by the Commenter (Associating patterns in 
movement and diving behavior with sonar use during military training 
exercises: A case study using satellite tag data from Cuvier's beaked 
whales at the Southern California Anti-submarine Warfare Range (Falcone 
et al., 2017)) was not available at the time the BRFs were developed. 
However, NMFS and the Navy have reviewed the article and concur that 
neither this article nor any

[[Page 46317]]

other new information that has been published or otherwise conveyed 
since the proposed rule was published changes the assessment of impacts 
or conclusions in the 2020 MITT FSEIS/OEIS or in this rulemaking. 
Additionally, the Navy's current beaked whale BRF covers the responses 
observed in this study since the beaked whale risk function is more 
sensitive than the other risk functions at lower received levels. The 
researchers involved with the study are still refining their analytical 
approach and integrating additional statistical parameters for future 
reporting. Nonetheless, the new information and data presented in the 
article were thoroughly reviewed by the Navy and will be quantitatively 
incorporated into future behavioral response functions, as appropriate, 
when and if other new data that would meaningfully change the functions 
would necessitate their revision.
    Furthermore, ongoing Navy funded beaked whale monitoring at the 
same site where the dipping sonar tests were conducted has not 
documented habitat abandonment by beaked whales. Passive acoustic 
detections of beaked whales have not significantly changed over ten 
years of monitoring (DiMarzio et al., 2018, updated in 2020). From 
visual surveys in the area since 2006 there have been repeated 
sightings of: The same individual beaked whales, beaked whale mother-
calf pairs, and beaked whale mother-calf pairs with mothers on their 
second calf (Schorr et al., 2018, 2020). Satellite tracking studies of 
beaked whales documented high site fidelity to this area (Schorr et 
al., 2018, updated in 2020).
    Comment 9: A Commenter recommends that NMFS (1) explain why, if the 
constants and exponents for onset mortality and onset slight lung 
injury thresholds for the current phase of incidental take rulemaking 
for the Navy (Phase III) have been amended to account for lung 
compression with depth, they result in lower rather than higher 
absolute thresholds when animals occur at depths greater than 8 m and 
(2) specify what additional assumptions were made to explain this 
counterintuitive result.
    Response: The derivation of the explosive injury equations, 
including any assumptions, is provided in the 2017 technical report 
titled ``Criteria and Thresholds for U.S. Navy Acoustic and Explosive 
Effects Analysis (Phase III).'' Specifically, the equations were 
modified in Phase III to fully incorporate the injury model in Goertner 
(1982), specifically to include lung compression with depth. NMFS 
independently reviewed and concurred with this approach.
    The impulse mortality/injury equations are depth dependent, with 
thresholds increasing with depth due to increasing hydrostatic pressure 
in the model for both the previous 2015-2020 phase of rulemaking (Phase 
II) and Phase III. The underlying experimental data used in Phase II 
and Phase III remain the same, and two aspects of the Phase III 
revisions explain the relationships the Commenter notes:
    (1) The numeric coefficients in the equations are computed by 
inserting the Richmond et al. (1973) experimental data into the model 
equations. Because the Phase III model equation accounts for lung 
compression, the plugging of experimental exposure values into a 
different model results in different coefficients. The numeric 
coefficients are slightly larger in Phase III versus Phase II, 
resulting in a slightly greater threshold near the surface.
    (2) The rate of increase for the Phase II thresholds with depth is 
greater than the rate of increase for Phase III thresholds with depth 
because the Phase III equations take into account the corresponding 
reduction in lung size with depth (making an animal more vulnerable to 
injury per the Goertner model), as the Commenter notes.
    Ranges to effect are based on these injury thresholds, in addition 
to geometry of exposure (location of an animal relative to the 
explosive charge, horizontally and vertically), propagation 
environment, and the impulse integration duration.
    Comment 10: A Commenter recommends that NMFS use onset mortality, 
onset slight lung injury, and onset GI tract injury thresholds rather 
than the 50-percent thresholds to estimate both the numbers of marine 
mammal takes and the respective ranges to effect. If NMFS does not 
implement the recommendation, the Commenter further recommends that 
NMFS (1) specify why it is inconsistently basing its explosive 
thresholds for Level A harassment on onset of PTS and Level B 
harassment on onset of TTS and onset of behavioral response, while the 
explosive thresholds for mortality and Level A harassment are based on 
the 50-percent criteria for mortality, slight lung injury, and GI tract 
injury, (2) provide scientific justification supporting that slight 
lung and GI tract injuries are less severe than PTS and thus the 50-
percent rather than onset criteria are more appropriate for estimating 
Level A harassment for those types of injuries, and (3) justify why the 
number of estimated mortalities should be predicated on at least 50 
percent rather than 1 percent of the animals dying.
    Response: As appropriate, NMFS and the Navy have used a combination 
of exposure thresholds and consideration of mitigation to inform the 
take estimates. The Navy used the range to one percent risk of 
mortality and injury (referred to as ``onset'' in the 2020 MITT FSEIS/
OEIS) to inform the development of mitigation zones for explosives. 
Ranges to effect based on one percent risk criteria were examined to 
ensure that explosive mitigation zones would encompass the range to any 
potential mortality or non-auditory injury, affording actual protection 
against these effects. In all cases, the mitigation zones for 
explosives extend beyond the range to one percent risk of non-auditory 
injury, even for a small animal (representative mass = 5 kg).
    Given the implementation and expected effectiveness of this 
mitigation, the application of the indicated threshold is appropriate 
for the purposes of estimating take. Using the 1 percent non-auditory 
injury risk criteria to estimate take would result in an over-estimate 
of take, and would not afford extra protection to any animal. 
Specifically, calculating take based on marine mammal density within 
the area that an animal might be exposed above the 1 percent risk 
criteria would over-predict effects because many of those exposures 
will not happen because of the effective mitigation. The Navy, in 
coordination with NMFS, has determined that the 50 percent incidence of 
occurrence is a reasonable representation of a potential effect and 
appropriate for take estimation, given the mitigation requirements at 
the 1 percent threshold, and the area ensonified above this threshold 
would capture the appropriate reduced number of likely injuries.
    Although the commenter implies that the Navy did not use extensive 
lung hemorrhage as indicative of mortality, that statement is 
incorrect. Extensive lung hemorrhage is assumed to result in mortality, 
and the explosive mortality criteria are based on extensive lung injury 
data. See the 2017 technical report titled ``Criteria and Thresholds 
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III).''
    Comment 11: A Commenter stated that NMFS, following the Navy, has 
applied a post-modeling adjustment to its estimate of lethal take that 
substantially reduces the total number. That adjustment, in the case of 
serious injury and mortality, purports to account for the effectiveness 
of visual observers in detecting marine mammals within the blast zone 
of an underwater

[[Page 46318]]

explosion (or within the radius of permanent acoustic injury), but 
NMFS' borrowed methods here are non-transparent and misconceived. The 
Navy's DSEIS/OEIS for the MITT Study Area starts with the species-
specific g(0) factors applied in professional marine mammal abundance 
surveys (the probability that an object that is on the line is detected 
using standard line-transect methods), then multiplies them by simple 
factors to reflect the relative effectiveness of its Lookouts in 
routine operating conditions. Yet the Navy's sighting effectiveness is 
likely to be much poorer than that of experienced biologists dedicated 
exclusively to marine mammal detection, operating under conditions that 
maximize sightings. In any case, the public has no meaningful way to 
further evaluate the agencies' adjustment since the proposed rule does 
not provide the scores used to generate the effectiveness factor or the 
agencies' pre-adjustment take numbers, nor does the Navy in the 
ancillary report NMFS references. The Commenter suggests that ``[s]ince 
the Navy has yet to determine the effectiveness of its mitigation 
measures, it is premature to include any related assumptions to reduce 
the numbers of marine mammal takes.'' Another Commenter recommends that 
NMFS (1) specify the total numbers of model estimated Level A 
harassment (PTS) and mortality takes rather than reduce the estimated 
numbers of takes based on the Navy's post-model analyses and (2) 
include the model-estimated Level A harassment and mortality takes in 
its negligible impact determination analyses.
    Response: The consideration of marine mammal avoidance and 
mitigation effectiveness is integral to NMFS' and the Navy's overall 
analysis of impacts from sonar and explosive sources. NMFS has 
independently evaluated the method and agrees that it is appropriately 
applied to augment the model in the prediction and authorization of 
injury and mortality as described in the rule. Details of this analysis 
are provided in the Navy's 2018 technical report titled ``Quantifying 
Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and 
Analytical Approach for Phase III Training and Testing.'' Additional 
information on the mitigation analysis also was included in the 
proposed rule and NMFS disagrees with the Commenter's suggestion that 
there was not enough information by which to evaluate the Navy's post-
modeling calculations. Also, it should be noted that even before 
consideration of mitigation effectiveness, there were no modeled 
mortalities to any marine mammals.
    Sound levels diminish quickly below levels that could cause PTS. 
Specifically, behavioral response literature, including the recent 3S 
and SOCAL BRS studies, indicate that multiple species from different 
cetacean suborders do in fact avoid approaching sound sources by a few 
hundred meters or more, which would reduce received sound levels for 
individual marine mammals to levels below those that could cause PTS 
(see Appendix B of the ``Criteria and Thresholds for U.S. Navy Acoustic 
and Explosive Impacts to Marine Mammals and Sea Turtles Technical 
Report'' (U.S. Department of the Navy, 2017) and Southall et al. 
(2019a)). The ranges to PTS for most marine mammal groups are within a 
few tens of meters and the ranges for the most sensitive group, the HF 
cetaceans, average about 200 m, to a maximum of 270 m in limited cases. 
For blue whales and other LF cetaceans, the range to PTS is 65 m for 
MF1 30 sec duration exposure, which is well within the mitigation zones 
for hull-mounted MFAS. Therefore, the anticipated avoidance to the 
distances discussed would greatly reduce the likelihood of impacts to 
hearing such as TTS and PTS. As discussed in the Navy's report, animats 
in the Navy's acoustic effects model do not move horizontally or 
``react'' to sound in any way. Accordingly, NMFS and the Navy's 
analysis appropriately applies a quantitative adjustment to the 
exposure results calculated by the model (which does not consider 
avoidance or mitigation).
    As discussed in the Navy's report, the Navy's acoustic effects 
model does not consider procedural mitigations (i.e., power-down or 
shut-down of sonars, or pausing explosive activities when animals are 
detected in specific zones adjacent to the source), which necessitates 
consideration of these factors in the Navy's overall acoustic analysis. 
Credit taken for mitigation effectiveness is extremely conservative. 
For example, if Lookouts can see the whole area, they get credit for it 
in the calculation; if they can see more than half the area, they get 
half credit; if they can see less than half the area, they get no 
credit. Not considering animal avoidance and mitigation effectiveness 
would lead to a great overestimate of injurious impacts. NMFS concurs 
with the analytical approach used, i.e., we believe the estimated take 
by Level A harassment numbers represent the maximum number of these 
takes that are likely to occur and it would not be appropriate to 
authorize a higher number or consider a higher number in the negligible 
impact analysis.
    The Navy assumes that Lookouts will not be 100 percent effective at 
detecting all individual marine mammals within the mitigation zones for 
each activity. This is due to the inherent limitations of observing 
marine species and because the likelihood of sighting individual 
animals is largely dependent on observation conditions (e.g., time of 
day, sea state, mitigation zone size, observation platform) and animal 
behavior (e.g., the amount of time an animal spends at the surface of 
the water). The Navy quantitatively assessed the effectiveness of its 
mitigation measures on a per-scenario basis for four factors: (1) 
Species sightability, (2) a Lookout's ability to observe the range to 
permanent threshold shift (for sonar and other transducers) and range 
to mortality (for explosives), (3) the portion of time when mitigation 
could potentially be conducted during periods of reduced daytime 
visibility (to include inclement weather and high sea-state) and the 
portion of time when mitigation could potentially be conducted at 
night, and (4) the ability for sound sources to be positively 
controlled (e.g., powered down). The Navy's report clearly describes 
how these factors were considered, and it is not necessary to view the 
many tables of numbers generated in the assessment to evaluate the 
method.
    The g(0) values used by the Navy for their mitigation effectiveness 
adjustments take into account the differences in sightability with sea 
state, and utilize averaged g(0) values for sea states of 1-4 and 
weighted as suggested by Barlow (2015). Using g(0) values is an 
appropriate and conservative approach (i.e., underestimates the 
protection afforded by the Navy's mitigation measures) for the reasons 
detailed in the technical report. For example, during line-transect 
surveys, there are typically two primary observers searching for 
animals. Each primary observer looks for marine species in the forward 
90-degree quadrant on their side of the survey platform and scans the 
water from the vessel out to the limit of the available optics (i.e., 
the horizon). Because Navy Lookouts focus their observations on 
established mitigation zones, their area of observation is typically 
much smaller than that observed during line-transect surveys. The 
mitigation zone size and distance to the observation platform varies by 
Navy activity. For example, during hull-mounted mid-frequency active 
sonar activities, the mitigation zone extends 1,000 yd from the ship

[[Page 46319]]

hull. During the conduct of training and testing activities, there is 
typically at least one, if not numerous, support personnel involved in 
the activity (e.g., range support personnel aboard a torpedo retrieval 
boat or support aircraft). In addition to the Lookout posted for the 
purpose of mitigation, these additional personnel observe for and 
disseminate marine species sighting information amongst the units 
participating in the activity whenever possible as they conduct their 
primary mission responsibilities. However, as a conservative approach 
to assigning mitigation effectiveness factors, the Navy elected to 
account only for the minimum number of required Lookouts used for each 
activity; therefore, the mitigation effectiveness factors may 
underestimate the likelihood that some marine mammals may be detected 
during activities that are supported by additional personnel who may 
also be observing the mitigation zone.
    Although NAEMO predicted PTS, no mortality or non-auditory injury 
were predicted by NAEMO. Of these two non-auditory effects (mortality 
and non-auditory injury), only mortality would have been subject to 
mitigation consideration in the quantitative analysis, if there had 
been any. Also, as discussed in Comment 43, the Navy will be providing 
NMFS with a report summarizing the status of and/or providing its final 
assessment on the Navy's Lookout Effectiveness Study following the end 
of CY 2021.
    Comment 12: One Commenter asserted that NMFS and the Navy make 
certain post-modeling adjustments to their estimates of non-lethal 
injury, on flawed assumptions about animal avoidance and mitigation 
effectiveness. A Commenter stated in regards to the method by which the 
Navy's post-model calculation considers avoidance specifically (i.e., 
assuming animals present beyond the range of PTS for the first few 
pings will be able to avoid it and incur only TTS, which results in a 
95 percent reduction in the number of estimated PTS takes predicted by 
the model), given that sound sources are moving, it may not be until 
later in an exercise that the animal is close enough to experience PTS, 
and it is those few close pings that contribute to the potential to 
experience PTS. Marine mammals may remain in important habitat, and the 
most vulnerable individuals may linger in an area, notwithstanding the 
risk of harm; marine mammals cannot necessarily predict where an 
exercise will travel. In addition, Navy vessels may move faster than 
the ability of the animals to evacuate the area. The Commenter 
expressed concern that this method underestimates the number of PTS 
takes and that NMFS should not create an under-supported, 
nonconservative adjustment for avoidance. The Commenter further 
suggested that the Navy could query the dosimeters on the animats in 
its model to test its assumption.
    Response: The consideration of marine mammals avoiding the area 
immediately around the sound source is provided in the Navy's 2018 
technical report titled ``Quantitative Analysis for Estimating Acoustic 
and Explosive Impacts to Marine Mammals and Sea Turtles.'' As the 
Commenter correctly articulates: ``For avoidance, the Navy assumed that 
animals present beyond the range to onset PTS for the first three to 
four pings are assumed to avoid any additional exposures at levels that 
could cause PTS. That equated to approximately 5 percent of the total 
pings or 5 percent of the overall time active; therefore, 95 percent of 
marine mammals predicted to experience PTS due to sonar and other 
transducers were instead assumed to experience TTS.''
    In regard to the comment about vessels moving faster than animals' 
ability to get out of the way, as discussed in the Navy's 2018 
technical report titled ``Quantitative Analysis for Estimating Acoustic 
and Explosive Impacts to Marine Mammals and Sea Turtles,'' animats in 
the Navy's acoustic effects model do not move horizontally or ``react'' 
to sound in any way, necessitating the additional step of considering 
animal avoidance of close-in PTS zones. NMFS independently reviewed 
these assumptions and this approach and concurs that they are fully 
supported by the best available science. Based on a growing body of 
behavioral response research, animals do in fact avoid the immediate 
area around sound sources to a distance of a few hundred meters or more 
depending upon the species. Avoidance to this distance greatly reduces 
the likelihood of impacts to hearing such as TTS and PTS, respectively. 
Specifically, the ranges to PTS for most marine mammal groups are 
within a few tens of meters and the ranges for the most sensitive 
group, the HF cetaceans, average about 200 m, to a maximum of 270 m in 
limited cases. The Commenter's point about speed is not applicable to 
the initially distant animals that are discounted by this method, most 
of which would be able to avoid the source as there is more time 
(because they are farther from the source) to do so. Further, the 
Commenter ignores the corollary to their point, which is that given the 
speed the Navy vessels operating sonar are typically traveling relative 
to the speed and direction of marine mammals, the likelihood of 
individuals remaining in close enough proximity to the source for a 
duration that would result in TTS or PTS is lessened.
    Querying the dosimeters of the animats would not produce useful 
information since, as discussed previously, the animats do not move in 
the horizontal and are not programmed to ``react'' to sound or any 
other stimulus.

Humpback Whales

    Comment 13: Commenters assert that the proposed reporting 
requirement for MF1 MFAS (with the lack of any restriction on actual 
sonar use) in the Chalan Kanoa Reef and Marpi Reef Geographic 
Mitigation Areas would not protect humpback whales, and particularly 
calves during this sensitive life stage. Further, the Commenters note 
that because these areas have not been a high[hyphen]use area for the 
Navy and ASW training events and are ``considered generally unsuitable 
for training needs,'' (85 FR 48388), there is no justification for 
failing to prohibit sonar use in this sensitive humpback whale habitat 
off Saipan. One Commenter recommended that NMFS prohibit use of MF1 
sonar in the Marpi Reef and Chalan Kanoa Reef Geographic Mitigation 
Areas during the months that humpbacks are present in the Marianas 
while another suggested a year-round prohibition.
    Response: Following extensive discussions with the Navy during 
which more specific granular information about the Navy's likely 
activity was provided and the practicability of additional restrictions 
were considered, new information about humpback whale occurrence in the 
mitigation areas emerged, and new analyses were conducted (see the 
Estimated Take of Marine Mammals section), NMFS established a 20-hr 
annual cap from December 1-April 30 on the use of hull-mounted MF1 MFAS 
for these two Geographic Mitigation Areas (20 hrs total for both areas 
combined) to minimize sonar exposure and reduce the amount and/or 
severity of take by Level B harassment (behavioral disturbance and/or 
TTS) of humpback whales in these important reproductive areas. It is 
important to note that in the Navy's rulemaking/LOA application and 
NMFS' associated analysis for the proposed rule, while high amounts of 
sonar training may not have been expected, the amount of sonar use in 
these areas had not been limited.
    Our evaluation of potential mitigation measures includes 
consideration of both

[[Page 46320]]

(1) the manner in which, and the degree to which, implementation of the 
potential measure(s) is expected to reduce adverse impacts to marine 
mammal species or stocks and their habitat and (2) the practicability 
of the measures for applicant implementation, which in this case 
includes the impact on the Navy's military readiness activities. While 
we did consider completely restricting MF1 MFAS in the two Geographic 
Mitigation Areas, we also considered the Navy's broader need for 
flexibility as well as the specific need not to restrict these shallow-
water training areas entirely in the MITT Study Area given the 
proximity to forward deployed operations and the higher likelihood of a 
need to have the option to conduct training quickly to respond to 
emergent national security threats. The Navy expects current and future 
use of the two Geographic Mitigation Areas to remain low, but the 20-hr 
cap will allow the Navy flexibility to engage in a small amount of 
necessary training, most likely such as a Small Coordinated ASW 
Exercise or TRACKEX event(s), which could occur up to five days, but no 
more than four hours per day (or similar configuration totalling no 
more than 20 hrs). Areas of shallow depths are limited in the Mariana 
Archipelago, and NMFS determined (with the Navy's input) that it would 
be impracticable to completely limit the use of sonar at the Chalan 
Kanoa Reef and Marpi Reef due to the requirement to have access to such 
bathymetry for training purposes in order to support mission 
requirements as established by operational Commanders. The reduction in 
potential exposure of humpback whales to sonar in these areas and at 
this time (i.e., the short overall and daily exposure) would reduce the 
likelihood of impacts that could affect reproduction or survival, by 
minimizing impacts on calves during this sensitive life stage, avoiding 
the additional energetic costs to mothers of avoiding the area and 
minimizing the chances that important behaviors (e.g., cow-calf 
communication, breeding behaviors) are interrupted to the point that 
survivorship or reproduction are impacted. Therefore, we have 
determined that the 20-hr cap on MF1 MFAS sonar in the two Geographic 
Mitigation Areas will meaningfully reduce impacts on the affected 
humpback whales and, further, be practicable for Navy implementation. 
As an additional measure, the Navy will also now report all active 
sonar use (all bins, by bin) in these areas between December 1 and 
April 30 to NMFS in their annual reports. This will allow NMFS to 
evaluate the sonar use in the two Geographic Mitigation Areas over the 
seven-year period and to determine if further mitigation is warranted.
    Comment 14: A Commenter recommended a prohibition on mid-frequency 
air deployed dipping sonar, year-round in the Geographic Mitigation 
Areas. The Commenter also commented that dipping sonar has been shown 
to have disproportionate impacts on beaked whales and may impact other 
species such as humpback whales in a similar manner, due to the 
unpredictability of the signal.
    Response: Regarding the applicability of the data the Commenter 
cites to humpback whale responses, the research was focused exclusively 
on beaked whales and, further, in regard to the data cited, certain 
limitations are still under investigation such as the proximity of the 
source and other factors. Behavioral responses of beaked whales from 
dipping and other sonars cannot be universally applied to other marine 
mammal species, especially since beaked whales are known to be more 
sensitive to lower level sounds, which is reflected in our analysis 
through a lower behavioral harassment threshold. For example, Navy-
funded behavioral response studies of blue whales to simulated surface 
ship sonar have demonstrated there are distinct individual variations 
as well as strong behavioral state considerations that influence any 
response or lack of response. The majority of take by Level B 
harassment results from MF1 sonar, which is practicable to limit in the 
Chalan Kanoa Reef and Marpi Reef Geographic Mitigation Areas. Sonar 
activities in this area have been limited historically, there is 
insufficient evidence to suggest that MF4 sonar would have 
disproportionately adverse effects, and further limitation of MF4 
dipping sonar use in these areas would not be expected to meaningfully 
reduce impacts to humpback whales.
    With regards to beaked whales, water depths in the Chalan Kanoa 
Reef and Marpi Reef Geographic Mitigation Areas are not suitable 
habitats for beaked whales. There is no evidence to suggest that 
prohibiting the use of mid-frequency dipping sonar in the Geographic 
Mitigation Areas would have any benefit to beaked whales.
    Comment 15: A Commenter recommended prohibiting use of low-
frequency active sonar from December through April in the Marpi Reef 
and Chalan Kanoa Reef Geographic Mitigation Areas, because they assert 
that baleen whales are vulnerable to the impacts of low-frequency 
active sonar, particularly in calving areas where low-amplitude 
communication calls between mothers and calves can be easily masked.
    Response: Low-frequency sonar use in this rule has been 
significantly scaled down from previous authorizations. The Navy is 
only seeking authorization for 11 hrs or less per year of low-frequency 
sonar use in the MITT Study Area, with most of these systems used 
further offshore. Furthermore, the most used source at approximately 10 
hrs (LF5) has source levels less than 180 dB and one hour of LF4 with 
source levels greater than 180 dB and less than or equal to 200 dB, 
with the associated harassment zones significantly smaller than for 
MF1. Based on historical sonar use in the MITT Study Area, it is highly 
unlikely that the few planned low-frequency sonar hours would occur in 
the Geographic Mitigation Areas from December through April. Given 
that, and the smaller impact zones, a prohibition would have very 
limited or no potential benefit to humpback whales and other baleen 
whales and would unnecessarily impose a restriction on training and 
testing in the MITT Study Area.
    Comment 16: A Commenter recommended extending the Marpi Reef 
Geographic Mitigation Area boundaries to include a buffer that 
encompasses the humpback whale sightings data beyond the 400-m depth 
contour and the southernmost point of the proposed Marpi Reef 
Geographic Mitigation Area.
    Response: NMFS extended the boundary out to the 400-m isobath for 
both Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas prior 
to the publication of the proposed rule. NMFS and the Navy considered 
using bathymetry to define the Marpi Reef Geographic Mitigation Area 
when initially evaluating potential mitigation areas, but instead 
relied on confirmed sightings of humpback whales to define the area. 
After reviewing the detailed bathymetry of the reef coupled with marine 
mammal sightings, NMFS and the Navy reevaluated how the Marpi Reef 
Geographic Mitigation Area was bounded and redefined the area based on 
the extent of the 400-m isobath. Given most sightings of humpback 
whales were in waters less than 200 m in depth, this provides an 
additional buffer between most sighting locations and the boundary for 
the area. Seafloor areas extending beyond the reef are not necessarily 
areas of potential biological importance (i.e., whales may have been 
transiting to or from the reef when sighted). Scientists from NMFS' 
Pacific Islands Fisheries Science Center, who have conducted numerous 
humpback

[[Page 46321]]

whale surveys in Hawaii and the Mariana Islands, have observed that the 
majority of humpback whale breeding activity (mother-calf pairs, 
competitive behavior) happens in water depths of 200 m or less, with 
more mother-calf pairs in water depths 50 m or less (Hill et al., 
2020). In addition, during a review of the Marpi Reef sightings and 
bathymetry, the Navy found that the mitigation graphics in Appendix I 
(Geographic Mitigation Assessment) of the 2020 MITT FSEIS/OEIS had 
errors where bathymetric lines plotted were incorrectly shifted. This 
issue was fixed using a more accurate small-scale bathymetric dataset. 
Revised figures for the 2020 MITT FSEIS/OEIS show that all humpback 
whale sightings near Marpi Reef where suspected reproductive behaviors 
were observed (mother-calf pairs, competitive behavior) were shallower 
than the 200-m isobath.
    Comment 17: A Commenter recommends implementing vessel speed 
restrictions from December through April in the Marpi Reef and Chalan 
Kanoa Reef Geographic Mitigation Areas as they argue that ship strike 
and vessel noise pose a serious risk to humpback whales, particularly 
in calving and breeding areas. They say it is important that NMFS 
prescribe vessel speed limits in this important breeding habitat and 
that mandatory speed limits, such as those that NMFS has put in place 
to protect North Atlantic right whales, have proven effective. NMFS has 
no basis on which to determine that its ``notification message'' 
measure--which would depend on non-specialist, non-dedicated Navy 
observers operating effectively in unfavorable sea states--would be as 
effective, or effective at all. The Commenter states there is no reason 
why NMFS cannot reasonably accommodate national security needs to 
create exceptions to the rule if needed.
    Response: To avoid physical disturbance and strike from vessel 
movements, the Navy maneuvers to maintain a 500 yd mitigation zone from 
whales and other marine mammals (except bow-riding dolphins). As 
further described in Section 5.3.4.1 (Vessel Movement) of the 2020 MITT 
FSEIS/OEIS implementing mitigation to limit vessel speeds in the MITT 
Study Area would be incompatible with the Navy's criteria for safety, 
sustainability, and mission requirements. For example, Navy vessel 
operators need to train to proficiently operate vessels as they would 
during military missions and combat operations, including being able to 
react to changing tactical situations and evaluate system capabilities. 
Navy studies from other range complexes demonstrated that median speeds 
near coasts are already low, varying from 5 to 12 knots. Furthermore, 
given that there have been no vessel strikes involving humpback whales 
or other marine mammals while Navy vessels conducted training and 
testing activities in the MITT Study Area, implementing vessel speed 
restrictions in the Geographic Mitigation Areas or other locations in 
the Study Area would not be an effective mitigation measure because it 
would not result in discernible avoidance or reduction of impacts. 
Given the lack of meaningful reduction in impacts combined with the 
impracticability of ship speed restrictions, NMFS has found that this 
measure is not warranted and it is not required in this rule.

Serious Injury and Mortality, Beaked Whales

    Comment 18: Commenters stated that NMFS underestimated serious 
injury and mortality for beaked whales around the Mariana Islands, 
ignored the best available scientific information, and failed to make 
any meaningful assessment and negligible impact determination of the 
likelihood that Navy training and testing activities triggered 
strandings in the MITT Study Area. A Commenter stated that NMFS has 
failed to demonstrate a rational basis for its assumption that ``[n]o 
mortality or Level A harassment [of beaked whales] is expected'' from 
MITT activities, rendering NMFS's preliminary determination of 
negligible impact arbitrary and capricious. Another Commenter noted 
that in the Guam press, at least six beaked whale stranding events, 
each involving as many as three animals, have been reported in the 
archipelago since 2006, as compared with only a single stranding in the 
previous 35 years. That number of recent stranding events was 
subsequently corrected to eight, in a paper that appeared earlier this 
year in a major, peer-reviewed journal. The Simonis et al. (2020) 
paper, whose co-authors include several NMFS biologists, correlated 
four of these events with Navy operations, a correlation that it 
describes as ``highly significant.'' The Commenter argued that the best 
available science shows that serious injuries and mortalities are 
likely to far exceed the number of reported strandings. Numerous 
studies along multiple lines of evidence, including post-stranding 
pathology, laboratory study of organ tissue, and theoretical work on 
dive physiology, in addition to expert reviews, indicate that 
behaviorally-mediated injury and mortality is occurring through 
maladaptive alteration of the dive pattern in response to Navy sonar 
exposure--impacts that occur at sea, independent of a whale's 
stranding. The Commenter argues that in light of the available 
scientific evidence, this position is both arbitrary and irresponsible. 
They state that NMFS' method in the proposed rule is to cast doubt on 
an undefined subset of previous stranding events on the grounds that 
the precise mechanism of harm could not be established, even while 
describing in detail the abundance of pathological and forensic 
evidence.
    In a related comment, another Commenter asserted that although NMFS 
does not expect injury or mortality of any of beaked whales to occur as 
a result of the Navy's active sonar training exercises, NMFS's 
justification for authorizing beaked whale mortalities under Phase I 
and the previous Phase II regulations is still valid. The Commenter 
argues that NMFS cannot ignore that there remains the potential for the 
operation of MFAS to contribute to the mortality of beaked whales. 
Given that the potential for beaked whale mortalities cannot be 
obviated, the Commenter recommends that NMFS authorize at least 10 
mortality takes of beaked whales associated with MFA sonar use in the 
MITT Study Area in the final rule.
    Response: In the final rule, NMFS has included additional 
information and analysis and expanded the explanation of why the best 
available science does not indicate that the Navy's activities are 
likely to result in mortality of beaked whales through stranding. 
Please see the Stranding subsection of the Potential Effects of 
Specified Activities on Marine Mammals and Their Habitat section, which 
addresses the issues raised by the Commenters; comments not addressed 
in that section are addressed below. To specifically correct an 
inaccuracy in the Comment, it should be noted, that of the eight events 
the Commenter refers to, only three had Navy sonar use before. Four 
events cited in the paper was an error the authors acknowledged.
    In regard to the authorization of mortality in MMPA regulations for 
Phase I and II of MITT training and testing activities, the Commenter 
is in error. Mortality was authorized in the Phase I MITT final rule, 
in an abundance of caution given the events, worldwide, in which there 
was a causal link between naval sonar and strandings, and noting that 
there could be a stranding that co-occurred with Navy sonar that was 
not caused by it. However, the rule explicitly stated that

[[Page 46322]]

``Neither NMFS nor the Navy anticipates that marine mammal strandings 
or mortality will result from the use of mid- or high-frequency sonar 
during Navy exercises within the MIRC Study Area.'' However, no 
mortality was authorized in the Phase II final rule for the MITT Study 
Area. The Navy initially requested mortality takes of beaked whales, 
however, after further discussion of the lack of incidents in which 
strandings were causally associated with sonar in the Marianas, or a 
perceived reasonable likelihood that they would be at the time, NMFS 
and the Navy determined that authorization of mortality was not 
appropriate. NMFS does not argue that there is no possibility for 
mortality to occur as a result of Navy activities, rather, we reason 
that consideration of all applicable information (the best available 
science) does not indicate that such mortality is reasonably likely to 
result from the Navy's activities within the seven-year span of the 
rule.
    Comment 19: A Commenter stated that in addition to documenting the 
substantial risk of injury and mortality to beaked whales from MITT 
activities, Simonis et al. (2020) confirmed the existence of 
biologically important areas for beaked whales near Saipan and Tinian. 
The study found that at least three species of beaked whales--Cuvier's, 
Blainville's, and a third unidentified species that may be the 
ginkgo[hyphen]toothed beaked whale--occur in the Mariana Archipelago 
throughout the year, similar to other island[hyphen]associated 
populations around the world. The Commenter argues that before 
finalizing its MMPA take regulations and issuing an LOA, NMFS must 
fully evaluate this new scientific information, which supports the 
establishment of a geographic mitigation area in the waters around 
Saipan and Tinian to protect vulnerable beaked whales from Navy sonar.
    Response: NMFS has evaluated the new scientific information from 
Simonis et al. (2020) as well as years of field surveys conducted under 
interagency agreements between the Navy and NMFS Pacific Islands 
Fisheries Science Center and Navy-funded beaked whale monitoring, and 
there remains a lack of scientific information available on beaked 
whale distribution in the Marianas Islands. Simonis et al. (2020) 
confirm that the acoustic record from their HARPs indicates that the 
habitats near the recording locations are used by Blainville's, 
Cuvier's and an unidentified beaked whale, however, they only suggest 
that the locations ``may be considered as potentially important beaked 
whale habitat,'' given that beaked whales were present a large portion 
of the time at each recording site. Specifically, they note that the 
presence of beaked whale signals in a recording can be indicative of 
relative occurrence and seasonal fluctuations, however, given there are 
only two recorders, the relative occurrence may only be compared 
between the two locations, and the authors do not compare the 
recordings to any other locations, making it impossible to draw 
conclusions regarding how any inferred occurrence rates might compare 
to other parts of the MITT Study Area or the species' range. The 
information presented in Simonis et al. (2020), while informative, does 
not provide sufficient information to warrant the addition of 
geographic mitigation measures beyond the procedural mitigation 
measures put in place through this final rule to reduce the number and 
severity of takes for all marine mammals.
    Without sufficient scientific data on beaked whale habitat use, 
bathymetry, and seasonality, NMFS is unable to develop mitigation 
measures that will meaningfully further reduce impacts to beaked whales 
and not be impracticable for the Navy. That said, NMFS and the Navy are 
committed to further actions (see the Changes from the Proposed Rule to 
the Final Rule section) to expand the science and inform future 
management actions related to beaked whales in the MITT Study Area. For 
example, the Navy will co-fund the Pacific Marine Assessment Program 
for Protected Species (PACMAPPS) survey in spring-summer 2021 to help 
document beaked whale occurrence, abundance, and distribution in the 
Mariana Islands. This effort will include deployments of a towed array 
as well as floating passive acoustic buoys. The Navy will monitor 
future beaked whale occurrence within select portions of the MITT Study 
Area starting in 2022. Additionally, the Navy will include Cuvier's 
beaked whales as a priority species for analysis under a 2020-2023 
Navy-funded research program entitled Marine Species Monitoring for 
Potential Consequences of Disturbance (MSM4PCOD). Finally, the Navy 
will fund and co-organize with NMFS an expert panel to provide 
recommendations on scientific data gaps and uncertainties for further 
protective measure consideration to minimize the impact of Navy 
training and testing activities on beaked whales in the Mariana 
Islands.
    Comment 20: One Commenter made several recommendations related to 
NMFS' assessment and mitigation of beaked whale impacts. The Commenter 
recommended that given beaked whales infrequent exposure to active 
sonar in the MITT Study Area, more conservative behavioral response 
curves be used to predict behavioral disturbance. The Commenter also 
challenged NMFS' assertion that suitable alternative foraging habitat 
is available for beaked whales in the MITT Study Area. Noting the 
scarcity of beaked whale data, the Commenter recommended that acoustic 
monitoring be implemented as the preferred method for estimating 
density of beaked whales, instead of using Hawaii data and, further, 
recommended more broadly that acoustic monitoring of beaked whales be 
conducted to better understand the impacts of Navy activities on beaked 
whales. The Commenter recommended that the Navy be more transparent in 
their monitoring in sharing data indicating the timing of Navy 
activities in relation to strandings. The Commenter noted that 
additional personnel and support for local stranding response and 
records is needed in order to better investigate causes of strandings 
that coincide with Navy activities in the MITT Study Area. Last, the 
Commenter notes that in order to detect any trend in the population, 
there is a strong need to conduct consistent surveys, with adequate 
methods for the species under consideration, over multiple years.
    Response: Regarding the recommendation to modify the behavioral 
harassment thresholds (specifically, lower the received levels at which 
they would be considered taken) based on the infrequent exposures of 
beaked whales to sonar in the Marianas, we first note that although the 
amount of activities in the MITT Study Area is below the amount in the 
AFTT or HSTT study areas, active sonar has been in regular use in the 
MITT Study Area since the 1960s, and it is unlikely that marine mammals 
in the area are naive to sonar exposure. Further, while NMFS 
acknowledges the importance of context and considers it in evaluating 
behavioral responses, there is not sufficient data upon which to base a 
quantitative modification of the behavioral harassment thresholds. 
Further, the behavioral thresholds for beaked whales are already lower 
than for other taxa to address their sensitivity and, as with other 
taxa, take the form of a dose response curve, allowing for variation in 
individual responses given different contexts.
    Regarding the comment that NMFS claims that suitable alternative 
habitat options exist if beaked whales are disturbed during feeding is 
not credible, we first direct the Commenter to the discussion of the 
impacts of noise

[[Page 46323]]

exposure during feeding behaviors described in the Odontocete 
subsection of the Analysis and Negligible Impact Determination section, 
which discusses the energetic impacts that interruption of feeding 
bouts can have on feeding odontocetes if interruptions occur over 
repeated sequential days. However, in the context of the MITT Study 
Area, as predicted and discussed, the magnitude and severity of takes 
is such that disturbance of low-moderate levels is expected to occur on 
no more than a few non-sequential days for any individual beaked 
whales, which would not result in the sort of energetic concerns that 
the Commenter is raising. Further, the Commenter repeatedly references 
concerns for small resident populations of beaked whales with high site 
fidelity, but there are no data to confirm the population structure of 
beaked whales in this area and, again, the magnitude and severity is 
low such that, regardless, adverse energetic impacts would be unlikely 
to result from Navy activities.
    Regarding the recommendation that acoustic monitoring be 
implemented in order to provide better density information for beaked 
whales, and to better understand behavioral responses, as noted in the 
Changes from the Proposed Rule section, the Navy will be co-funding the 
Pacific Marine Assessment Program for Protected Species (PACMAPPS) 
survey in spring-summer 2021 to help document beaked whale occurrence, 
abundance, and distribution in the Mariana Islands. This effort will 
include deployments of a towed acoustic array as well as floating 
passive acoustic buoys. The Navy has further committed to monitoring 
future beaked whale occurrence within select portions of the MITT Study 
Area starting in 2022 (so as to not duplicate PACMAPPS efforts).
    Regarding the recommendation that the Navy be more transparent in 
their monitoring and sharing data indicating the timing of Navy 
activities in relation to strandings, there is certain information that 
the Navy is unable to share freely because it is classified. Specific 
classified information is shared in the Navy's classified monitoring 
reports, and the Navy has always cooperated to provide additional 
detail in an unclassified format when needed. Further, though, the Navy 
has specifically targeted, for monitoring pursuant to this rule, 
increased analysis for any future beaked whale stranding in the Mariana 
Islands to include detailed Navy review of available records of sonar 
use.
    Regarding the comment that additional personnel and support for 
local stranding response and records is needed in order to better 
investigate causes of strandings that coincide with Navy activities in 
the MITT Study Area, as discussed in the rule the Navy has committed to 
continuing to fund additional stranding response/necropsy analyses for 
the Pacific Islands region. Further, the Navy is submitting a proposal 
through the annual Federally Funded Research and Development Center 
(FFRDC) call to fund the Center for Naval Analysis (CNA) to develop a 
framework to improve the analysis of single and mass stranding events, 
including the development of more advanced statistical methods to 
better characterize the uncertainty associated with data parameters.
    Last, the Commenter notes that in order to detect any trend in the 
population, there is a strong need to conduct consistent surveys, with 
adequate methods for the species under consideration, over multiple 
years. NMFS and the Navy do not disagree with this recommendation and, 
as noted, the Navy and NMFS are co-funding the PACMAPPS survey and the 
Navy has committed to additional beaked whale surveys. However, the 
ability to conduct consistent surveys is dependent upon the 
availability of resources at both NMFS and the Navy, and surveys may 
not always be conducted with the ideal regularity.
    Comment 21: A Commenter recommends that the Navy conduct more 
visual monitoring efforts, at sea and along coastlines, for stranded 
cetaceans before, during, and after naval exercises.
    Response: It is not practicable for the Navy to conduct additional 
visual monitoring at sea and along the coastlines for stranded 
cetaceans before, during, and after training and testing activities 
beyond what will occur through the procedural mitigation requirements 
under this rule. Pursuant to the mitigation, the Navy will be required 
to conduct monitoring for marine mammals before, during, and after in-
water explosive exercises as described in the Mitigation Measures 
section of this rule. During operations of hull-mounted mid-frequency 
sonar and low frequency sonar above 200 dB, monitoring will be 
conducted in support of mitigation requirements, and during all 
operations of any sort the Navy will be required to report if any 
injured or dead marine mammals are observed and follow established 
incident reporting procedures. In addition, the Navy has been providing 
funding to augment stranding response and necropsy examinations in 
Hawaii and the Mariana Islands since 2018. Additional funding to 
continue this support has been programmed and is pending issuance in 
FY20.
    Comment 22: A Commenter recommends that NMFS consider the full 
range of options in determining the mitigation measures needed to meet 
its responsibility under both the ``negligible impact'' and ``least 
practicable adverse impact'' provisions of the MMPA for beaked whales. 
Given the expertise needed to produce an optimal mitigation plan, the 
Commenter strongly advises NMFS to assemble a group of subject-matter 
experts, including experts on beaked whale distribution, monitoring, 
and conservation from the Southwest Fisheries Science Center, 
researchers from the Pacific Islands Fisheries Science Center who have 
led the work on beaked whales in the archipelago, and outside experts 
on the conservation biology of beaked whales.
    Response: The procedural mitigation measures required by the final 
rule provide protection for all species of marine mammals by reducing 
the probability and severity of impacts from active sonar and 
explosives. As noted, there is limited data available addressing the 
distribution of marine mammals in the Marianas, and there is no 
information supporting the existence of any known biologically 
important areas that would warrant the development of a geographic 
mitigation area for beaked whales. NMFS had thorough discussions with 
the Navy about the possibility of crafting a mitigation measure to 
minimize any potential risk that Navy activities could contribute in 
any way to the potential stranding of beaked whales. These discussions 
included consideration of all public comments that recommended beaked 
whale mitigation measures. However, despite years of field surveys 
conducted under interagency agreements between the Navy and NMFS' PIFSC 
along with Navy funded beaked whale monitoring, there remains a lack of 
scientific information available on beaked whale distribution and other 
essential species information in the Mariana Islands. Without 
sufficient scientific data on beaked whale habitat use, bathymetry, and 
seasonality, and from that a better understanding of the circumstances 
that could affect the likelihood of a stranding in the MITT Study Area, 
NMFS is unable to develop mitigation measures that would meaningfully 
reduce the likelihood of stranding and/or will not result in 
unreasonable operational/practicability concerns.
    Consequently, NMFS recommended to the Navy that the two agencies 
convene a panel of experts, both from

[[Page 46324]]

the region, as well as beaked whale behavioral response experts from 
other geographic areas, and Navy experts on biology, operations, and 
mitigation to review the status of the science, identify data gaps, and 
identify information applicable for consideration for future mitigation 
through the Adaptive Management process. The Navy has agreed to fund 
and co-organize this effort. Additional measures that the Navy has 
agreed to conduct to increase understanding and decrease uncertainty 
around beaked whales in the MITT Study Area are discussed in the 
Monitoring section.
    Comment 23: A Commenter recommends that the impact assessment 
consider whether beaked whales would be startled by explosions or 
active sonar causing them to rush from great depths to the surface at 
dangerous speed causing injury from gas expansion in their blood and 
whether repeated impacts causing TTS could lead to PTS.
    Response: The proposed rule addressed the impacts the commenter 
raises in the Potential Effects of Specified activities on Marine 
Mammals and Their Habitat section (Acoustically Mediated Bubble Growth 
and other Pressure-related Injury). Further, NMFS has expanded the 
discussion and rationale describing why the Navy's activities are not 
expected to result in the mortality of beaked whales in the Stranding 
section of this final rule.
    As described in the proposed rule, very prolonged or repeated 
exposure to sound strong enough to elicit TTS, or shorter-term exposure 
to sound levels well above the TTS threshold, can cause PTS, however, 
circumstances that would be expected to lead to this are not present 
for Navy activities in the MITT Study Area. For this rulemaking, the 
Navy's modeling has considered the proximity of marine mammals to Navy 
activities and the likelihood of exposure to levels above which TTS or 
PTS might be incurred, throughout a full day (i.e., considering 
potential repeated exposures within a day), and very few PTS takes are 
expected (see the Estimated Take of Marine Mammals section). Further, 
as discussed in the Analysis and Negligible Impact Determination 
section, there is no information suggesting that any marine mammals 
will be exposed to levels resulting in TTS across more than a few non-
sequential days, much less at a level or duration that is expected to 
accrue to PTS across those days.
    Also of note, ongoing research on beaked whale response to sonar 
does not indicate a panic response and rush to the surface. Instead, 
beaked whales move away from the source underwater and increase the 
slope of their ascent glide to bring them further from the source 
(Falcone et al. 2017).
    Comment 24: A Commenter stated that similar to beaked whales, NMFS 
has failed to analyze seriously whether melon[hyphen]headed whales and 
other marine mammal species known to be vulnerable to harm from Navy 
sonar and explosives are likely to suffer injury and/or death from MITT 
activities.
    Response: There have not been significant instances of stranding of 
melon-headed whales or other blackfish species in the Mariana Islands. 
Effects analyses concluding that strandings of these species are 
unlikely to result from the Navy's activities are contained in the 2020 
MITT FSEIS/OEIS. In review of NMFS' and Guam Department of 
Agriculture's Division of Aquatic and Wildlife Resources stranding data 
from 1962 through February 2019, only two instances of melon-headed 
whale strandings were reported (1980 and 2015). Stranding data for 
other species over the same time period include: false killer whale 3 
(2000, 2003, 2007), dwarf sperm whale 4 (1970, 1974, 1993, 2002), pygmy 
killer whale 1 (1974), pygmy sperm whale 3 (1989 (2), 1997), sperm 
whale 6 (1962, 1993 (2), 2011, 2012, 2013), and short-finned pilot 
whale 1 (1980). Given the low numbers of strandings of these species in 
the Marianas and the absence of any evidence of association with active 
sonar operation, the likelihood that Navy activities would result in 
serious injury or mortality of these species is considered 
discountable.
    Comment 25: A Commenter stated that NMFS assumes, counter to the 
available evidence, that beaked whales around the Mariana Archipelago 
have no population structure and are part of large, cosmopolitan 
populations. While limited information on population structure is 
available, the best available science shows differences in the 
echolocation signal frequency of Blainville's beaked whales between the 
Northern Marianas Islands and other locations in the Pacific, Western 
Atlantic, and Gulf of Mexico, indicative of a population specific to 
the Northern Marianas Islands. This finding is consistent with studies 
in other parts of the world, which have demonstrated remarkable site-
fidelity in beaked whale populations. Range-limited populations have 
been found on the shelf break approximately 50 km east of Cape 
Hatteras, as well as off Canada, in the Mediterranean, off Southern 
California, in the Bahamas, and around the Hawaiian Islands.
    Response: There is no satellite tag or photographic identification 
data supporting the assertion that the populations around the Marianas 
are resident populations, much less identifying what the size or shape 
of those resident populations might be within the Mariana Islands 
(i.e., abundance and range size). The Commenter points to data 
differentiating vocalizations of Blainville's beaked whales in the 
Mariana Islands versus other parts of the Pacific, and to the presence 
of known resident populations of beaked whales in Hawaii and other 
islands of the world. These points support the potential for resident 
populations to exist in the Marianas, but do not provide any 
information that would support analyzing impacts in a manner 
differently than was done by the Navy and NMFS. Specifically, for 
example, even if the beaked whales within the Marianas comprise a 
separate population from those elsewhere in the Pacific, it would not 
suggest that beaked whales should be analyzed differently than they 
were within the MITT Study Area.
    While NMFS cannot explicitly define the beaked whale population 
structure at this time, the magnitude and severity of the estimated 
take and the negligible impact analyses remain valid and applicable 
based on the best available science regardless of whether the beaked 
whales in the MITT Study Area are from a larger global population or a 
Marianas Islands associated population. NMFS and the Navy are committed 
to actions that will expand our understanding of beaked whales, 
including their distribution in the MITT Study Area (see the Monitoring 
and Adaptive Management sections below for detailed descriptions). For 
example, the Navy will co-fund the Pacific Marine Assessment Program 
for Protected Species (PACMAPPS) survey in spring-summer 2021 to help 
document beaked whale occurrence, abundance, and distribution in the 
Mariana Islands. This effort will include deployments of a towed array 
as well as floating passive acoustic buoys. The Navy will monitor 
future beaked whale occurrence within select portions of the MITT Study 
Area starting in 2022. Additionally, the Navy will include Cuvier's 
beaked whales as a priority species for analysis under a 2020-2023 Navy 
research-funded program entitled Marine Species Monitoring for 
Potential Consequences of Disturbance (MSM4PCOD). Finally, the Navy 
will fund and co-organize with NMFS an expert panel to provide 
recommendations on scientific data gaps and uncertainties.

[[Page 46325]]

Mitigation and Monitoring

Least Practicable Adverse Impact Determination
    Comment 26: A Commenter cited two judicial decisions and commented 
that the ``least practicable adverse impact'' standard has not been 
met. The Commenter stated that contrary to the Pritzker Court decision, 
NMFS, while clarifying that population-level impacts are mitigated 
``through the application of mitigation measures that limit impacts to 
individual animals,'' has again set population-level impact as the 
basis for mitigation in the proposed rule. Because NMFS' mitigation 
analysis is opaque, it is not clear what practical effect this position 
may have on its rulemaking. The Commenter stated that the proposed rule 
is also unclear in its application of the ``habitat'' emphasis in the 
MMPA's mitigation standard, and that while NMFS' analysis is opaque, 
its failure to incorporate or even, apparently, to consider viable 
time-area measures suggests that the agency has not addressed this 
aspect of the Pritzker decision. The Commenter argued that the MMPA 
sets forth a ``stringent standard'' for mitigation that requires the 
agency to minimize impacts to the lowest practicable level, and that 
the agency must conduct its own analysis and clearly articulate it and 
not just parrot what the Navy says. The baselessness of this approach 
can be seen from the outcome of the Conservation Council decision, 
where the parties were able to reach a settlement agreement 
establishing time-area management measures, among other things, on the 
Navy's Southern California and Hawaii Range Complexes notwithstanding 
NMFS' finding, following the Navy, that all such management measures 
would substantially affect military readiness and were not practicable. 
Unfortunately, there is no indication in the proposed rule that NMFS 
has, as yet, done anything different here.
    Response: First, the Commenter's reference to mitigation measures 
implemented pursuant to a prior settlement agreement is entirely 
inapplicable to a discussion of NMFS' responsibility to ensure the 
least practicable adverse impact under the MMPA. Specifically, for 
those areas that were previously covered under the 2015 settlement 
agreement for the HSTT Study Area, it is essential to understand that: 
(1) The measures were developed pursuant to negotiations with the 
plaintiffs and were specifically not selected and never evaluated based 
on an examination of the best available science that NMFS otherwise 
applies to a mitigation assessment and (2) the Navy's agreement to 
restrictions on its activities as part of a relatively short-term 
settlement (which did not extend beyond the expiration of the 2013 
regulations) did not mean that those restrictions were practicable to 
implement over the longer term.
    Regarding the remainder of the comment, NMFS disagrees with much of 
what the Commenter asserts. First, we have carefully explained our 
interpretation of the least practicable adverse impact standard and how 
it applies to both stocks and individuals, including in the context of 
the Pritzker decision, in the Mitigation Measures section. Further, we 
have applied the standard correctly in this rule in requiring measures 
that reduce impacts to individual marine mammals in a manner that 
reduces the probability and/or severity of population-level impacts.
    When a suggested or recommended mitigation measure that would 
reduce impacts is not practicable, NMFS has explored variations of that 
mitigation to determine if a practicable form of related mitigation 
exists. This is clearly illustrated in NMFS' independent mitigation 
analysis process explained in the Mitigation Measures section of the 
final rule. First, some types of mitigation required under this rule 
are area-specific and vary by mitigation area, demonstrating that NMFS 
has engaged in a site-specific analysis to ensure mitigation is 
tailored when practicability demands, i.e., some forms of mitigation 
were practicable in some areas but not others. For instance, while it 
was not practicable for the Navy to restrict all use of the Chalan 
Kanoa Reef and Marpi Reef Geographic Mitigation Areas, NMFS did expand 
the seaward extent of the areas out to the 400-m isobath. Additionally, 
while it was not practicable for the Navy to eliminate all training in 
those two Geographic Mitigation Areas, restrictions in those areas have 
been expanded such that the Navy will not use explosives year-round and 
MF1 MFAS will be limited to 20 hours between December 1 and April 30 
annually to minimize impacts from sonar on humpback whales during the 
time when they are engaged in important reproductive behaviors.
    Regarding the comment about mitigation of habitat impacts, marine 
mammal habitat value is informed by marine mammal presence and use and, 
in some cases, there may be overlap in measures for the species or 
stock directly and for use of habitat. In this rule, we have required 
time-area mitigations based on a combination of factors that include 
higher densities and observations of specific important behaviors of 
marine mammals themselves, but also that clearly reflect preferred 
habitat (e.g., reproductive areas of Marpi and Chalan Kanoa Reefs, 
resting habitat for spinner dolphins in Agat Bay). In addition to being 
delineated based on physical features that drive habitat function 
(e.g., bathymetric features), the high densities and concentration of 
certain important behaviors (e.g., breeding, resting) in these 
particular areas clearly indicate the presence of preferred habitat. 
The Commenter seems to suggest that NMFS must always consider separate 
measures aimed at marine mammal habitat; however, the MMPA does not 
specify that effects to habitat must be mitigated in separate measures, 
and NMFS has clearly identified measures that provide significant 
reduction of impacts to both ``marine mammal species and stocks and 
their habitat,'' as required by the statute.
    NMFS agrees, however, that the agency must conduct its own 
analysis, which it has done here, and not just accept what is provided 
by the Navy. That does not mean, however, that NMFS cannot review the 
Navy's analysis of effectiveness and practicability of its proposed 
mitigation measures, which by regulation the Navy was required to 
submit with its application, and concur with those aspects of the 
Navy's analysis with which NMFS agrees. The Commenter seems to suggest 
that NMFS must describe in the rule in detail the rationale for not 
adopting every conceivable permutation of mitigation, which is neither 
reasonable nor required by the MMPA. NMFS has described our well-
reasoned process for identifying the measures needed to meet the least 
practicable adverse impact standard in the Mitigation Measures section 
in this rule, and we have followed the approach described there when 
analyzing potential mitigation for the Navy's activities in the MITT 
Study Area. Responses to specific recommendations for mitigation 
measures provided by the Commenter on the proposed rule are discussed 
separately.
    Comment 27: A Commenter noted that they have previously indicated 
that, under the least practicable adverse impact requirement, and more 
generally under the purposes and policies of the MMPA, Congress 
embraced a policy that minimizes, whenever it is practicable, the risk 
of killing or seriously injuring a marine mammal incidental to an 
activity subject to section 101(a)(5)(A), including taking measures in 
an authorization to eliminate or reduce the

[[Page 46326]]

likelihood of lethal taking. Accordingly, the Commenter had recommended 
that NMFS address this point explicitly in its least practicable 
adverse impact analysis and clarify whether it agrees that the 
incidental serious injury or death of a marine mammal always should be 
considered an adverse impact for purposes of applying the least 
practicable adverse impact standard. In the preamble to the Atlantic 
Fleet Training and Testing (AFTT) final rule, NMFS indicated that it 
was unnecessary or unhelpful to address explicitly the point made by 
the Commenter that an incidental death or serious injury of a marine 
mammal should always be considered an adverse impact on the species or 
stock (83 FR 57117). The Commenter disagrees. The Commenter does not 
see how NMFS can meet the mandate of the MMPA to reduce adverse impacts 
to the lowest level practicable if it does not first identify clearly 
which impacts are adverse and may require mitigation under section 
101(a)(5)(A)(i)(II)(aa). The Commenter appreciates NMFS' statement that 
it has adopted a practice to mitigate mortality to the greatest degree 
possible, but disagrees with the agency's conclusions that one 
mortality does not affect the population in a quantifiable or 
meaningful way. However, the MMPA requires NMFS to go beyond that and 
reduce any adverse impacts to the greatest extent practicable, even 
though population-level impacts are not significant.
    Response: NMFS continues to disagree that it is necessary or 
helpful to explicitly address the point the Commenter raises 
specifically in the discussion on the least practicable adverse impact 
standard. It is always NMFS' practice to mitigate serious injury and 
mortality to the greatest degree possible, as death is the impact that 
is most easily linked to reducing the probability of adverse impacts to 
populations. However, we cannot agree that one mortality will always 
decrease any population in a quantifiable or meaningful way. For 
example, for very large populations, one mortality may fall well within 
typical known annual variation and not have any effect on population 
rates. Mortality is not anticipated or authorized in this rule.
    Comment 28: A Commenter continues to recommend that NMFS clearly 
separate its application of the least practicable adverse impact 
requirement from its negligible impact determination. Once NMFS 
determines that an applicant's proposed activities would have a 
negligible impact, it still has a responsibility to determine whether 
the activities would nevertheless have adverse impacts on marine mammal 
species and stocks and their habitat. If so, NMFS must condition the 
authorization to eliminate or reduce those impacts whenever, and to the 
greatest extent, practicable. As the statute is written, it is 
inappropriate to conflate the two standards, as NMFS seems to be doing.
    Response: NMFS has made clear in this and other rules that the 
agency separates its application of the least practicable adverse 
impact requirement in the Mitigation Measures section from its 
negligible impact analyses and determinations for each species or stock 
in a separate section. Further, NMFS has made this separation clear in 
practice for years by requiring mitigation measures to reduce impacts 
to marine mammal species and stocks and their habitat for all projects, 
even those for which the anticipated take would clearly not approach 
the negligible impact threshold, even in the absence of mitigation.
    Comment 29: A Commenter recommended that NMFS follow an analysis 
consisting of three elements to (1) determine whether the impacts of 
the proposed activities are negligible at the species/stock level, (2) 
if so, determine whether some of those impacts nevertheless are adverse 
either to marine mammal species or stocks or key marine mammal habitat, 
and (3) if so, whether it is practicable for the applicant to reduce or 
eliminate those impacts through modifying those activities or by other 
means (e.g., requiring additional mitigation measures to be 
implemented).
    Response: In the Mitigation Measures section of the rule, NMFS has 
explained in detail our interpretation of the least practicable adverse 
impact standard, the rationale for our interpretation, and then how we 
implement the standard. The method the agency is using addresses all of 
the necessary components of the standard and produces effective 
mitigation measures that result in the least practicable adverse impact 
on both the species or stocks and their habitat. The Commenter has 
failed to illustrate why NMFS' approach is inadequate or why the 
Commenter's proposed approach would be better, and we therefore decline 
to accept the recommendation.
    Comment 30: Regarding the habitat component of the least 
practicable adverse impact standard, a Commenter recommends that NMFS 
(1) adopt a clear decision-making framework that recognizes the species 
and stock component and the marine mammal habitat component of the 
least practicable adverse impact provision and (2) always consider 
whether there are potentially adverse impacts on marine mammal habitat 
and whether it is practicable to minimize them. The MMPA requires that 
NMFS address both types of impacts, not that there be no overlap 
between the mitigation measures designed to reduce those impacts.
    Response: NMFS' decision-making framework for applying the least 
practicable adverse impact standard clearly recognizes the habitat 
component of the provision (see Mitigation Measures section of the 
rule). NMFS does always consider whether there are adverse impacts on 
habitat and how they can be mitigated. Marine mammal habitat value is 
informed by marine mammal presence and use and, in some cases, there 
may be overlap in measures for the species or stock directly and for 
use of habitat. In this rule, we have required time-area mitigation 
measures based on a combination of factors that include higher 
densities and observations of specific important behaviors of marine 
mammal species themselves, but also that clearly reflect preferred 
habitat (e.g., reproductive habitat off Marpi and Chalan Kanoa Reefs 
and resting habitat in Agat Bay). In addition to being delineated based 
on physical features that drive habitat function (e.g., bathymetric 
features), the high densities and concentration of certain important 
behaviors (e.g., reproduction, feeding, resting) in these particular 
areas clearly indicate the presence of preferred habitat. The Commenter 
seems to suggest that NMFS must include mitigation measures aimed at 
marine mammal habitat that are wholly separate from addressing adverse 
impacts directly on the species or stocks. However, the MMPA does not 
specify that effects to habitat must be mitigated in separate measures, 
and NMFS has clearly included measures that provide significant 
reduction of impacts to both marine mammal species or stocks and their 
habitat, as required by the statute.
    Comment 31: A Commenter recommended that NMFS rework its evaluation 
criteria for applying the least practicable adverse impact standard to 
separate the factors used to determine whether a potential impact on 
marine mammals or their habitat is adverse and whether possible 
mitigation measures would be effective.
    Response: In the Mitigation Measures section, NMFS has explained in 
detail our interpretation and application of the least practicable 
adverse impact standard. The Commenter has recommended an alternate way 
of

[[Page 46327]]

interpreting and implementing the least practicable adverse impact 
standard, in which NMFS would consider the effectiveness of a measure 
in our evaluation of its practicability. The Commenter erroneously 
asserts that NMFS currently considers the effectiveness of a measure in 
a determination of whether the potential effects of an activity are 
adverse, but the Commenter has misunderstood NMFS' practice--rather, 
NMFS appropriately considers the effectiveness of a measure in the 
evaluation of the degree to which a measure will reduce adverse impacts 
on marine mammal species or stocks and their habitat, as a less 
effective measure will less successfully reduce these impacts on marine 
mammals. Further, the Commenter has not provided information that shows 
that their proposed approach would more successfully evaluate 
mitigation against the LAPI standard, and we decline to accept it.
    Comment 32: A Commenter stated that although NMFS has written 
extensively on the least practicable adverse impact standard, it 
remains unclear exactly how each authorization's proposed ``mitigation 
measures are sufficient to meet the statutory legal standard,'' or even 
what standard NMFS is using. As such, the Commenter again recommends 
that NMFS address these shortcomings by adopting a simple, two-step 
analysis that more closely tracks the statutory provisions being 
implemented. As the Commenter has stated previously, the first step 
should be to identify impacts on marine mammal species or stocks or 
their habitat that, although negligible, are nevertheless adverse. If 
such impacts are identified, then NMFS must identify and require the 
applicant to adopt measures to reduce those impacts to the lowest level 
practicable. If NMFS is using some other legal standard to implement 
the least practicable adverse impact requirements, the Commenter 
further recommends that NMFS provide a clear and concise description of 
that standard and explain why it believes it to be ``sufficient'' to 
meet the statutory legal requirements.
    Response: NMFS disagrees with the Commenter's assertion that 
analysis of the rule's mitigation measures under the least practicable 
adverse impact standard remains unclear or that the suggested 
shortcomings exist. Further, the Commenter provides no rationale as to 
why the two-step process they describe is better than the process that 
NMFS uses to evaluate the least practicable adverse impact and, 
therefore, we decline to accept the recommendation.
    Comment 33: A Commenter stated that since NMFS has expounded on the 
least practicable adverse impact standard at some length in a series of 
proposed authorizations, it has been an evolutionary process that 
varies depending on each specific situation. The Commenter continues to 
recommend that NMFS adopt general regulations to govern the process and 
set forth the basic steps and criteria that apply across least 
practicable adverse impact determinations. Those standards should not 
be shifting on a case by-case basis, as now appears to be the case. 
Rather, the analytical framework and decision-making standards should 
be consistent across authorizations. Variations between authorizations 
should be based on the facts underlying each application, not the 
criteria that underpin the least practicable adverse impact standard.
    Response: The commenter misunderstands the agency's process. 
Neither the least practicable adverse impact standard nor NMFS' process 
for evaluating it shifts on a case-by-case basis. Rather, as the 
Commenter suggests should be the case, the evaluation itself is case-
specific to the proposed activity, the predicted impacts, and the 
mitigation under consideration.
    Regarding the recommendation to adopt general regulations, we 
appreciate the recommendation and may consider the recommended approach 
in the future. However, providing directly relevant explanations of 
programmatic approaches or interpretations related to the incidental 
take provisions of the MMPA in a proposed incidental take authorization 
is an effective and efficient way to provide information to and solicit 
focused input from the public. Further, this approach affords the same 
opportunities for public comment as a stand-alone rulemaking would.
    Geographic Mitigation Measures
    Comment 34: A Commenter cites the judicial decision in Pritzker, 
and suggests that NMFS should adjust its approach to geographic 
mitigation as follows: First, NMFS must not dismiss the existence of 
persistent areas of primary productivity. Second, NMFS must not 
conflate the lack of survey effort with an absence of biologically 
important habitat. Third, NMFS, in following the Navy, overlooks 
evidence of island-associated small or resident populations, and 
relative risk to those populations. It is entirely remiss for NMFS to 
ignore evidence of small and resident populations within the MITT Study 
Area and afford them no additional protections.
    Response: To support its argument that NMFS must not dismiss the 
existence of persistent areas of primary productivity, the Commenter 
cites to the 2019 MITT DSEIS/OEIS and its general discussion of the 
West Marianas Ridge area and areas of productivity, and references some 
general information about how certain features may be tied to 
biodiversity hotspots. The West Marianas Trench is a huge area hundreds 
of miles long. The commenter does not provide any information about 
particular features or areas that are specifically known to be 
important to marine mammals in the West Marianas Trench, much less 
provide any specific recommendations about how geographic mitigation 
might potentially provide a reduction in impacts that the Navy's 
activities might be having on marine mammal species or stocks and their 
habitat. As described in section I.4.1 of the 2020 MITT FSEIS/OEIS, 
which NMFS reviewed and concurs with, the available data do not 
indicate that the West Mariana Ridge or surrounding area is an area of 
key biological importance for marine mammals or other marine species, 
nor is it clear that limiting the use of sonar and explosives in the 
area would result in an avoidance or reduction of impacts. Therefore, 
the West Mariana Ridge area does not warrant geographic mitigation. 
NMFS does not dismiss the existence of persistent areas of primary 
productivity, however, NMFS is unaware of, and the Commenter has failed 
to demonstrate the existence of, data supporting areas or habitat of 
specific importance to marine mammals, nor has the Commenter 
recommended any particular geographic mitigation measure. Additional 
discussion of areas of primary productivity is included below in the 
response to Comment 35.
    Second, the commenter asserts that NMFS must not conflate the lack 
of survey effort with an absence of biologically important habitat. 
NMFS has not done this. In the final rule, we have clarified that there 
are no known biologically important areas for most of the species in 
the MITT Study Area. In addition, while both the Navy and NMFS have 
discussed the paucity of survey data and habitat information in and 
around the Marianas, and the limited amount of information indicating 
specific important habitat for marine mammals, we have not suggested 
that this lack of data indicates that no biologically important areas 
exist. However, in the absence of data supporting a specific area in 
which biologically important behaviors are known to be concentrated, or 
important

[[Page 46328]]

habitat is otherwise located, and in which a reasonable argument can be 
made that limitation of Navy activities would meaningfully reduce 
impacts to marine mammal species or stocks and their habitat, it is not 
reasonable to require geographic mitigation beyond the procedural 
mitigation that is already in place to reduce impacts to all marine 
mammals in all locations.
    Third, the Commenter asserts that NMFS overlooks evidence of 
island-associated small or resident populations, and relative risk to 
those populations. NMFS and the Navy acknowledge the potential for 
island-associated odontocete populations in the Marianas and, in fact, 
the species that the Commenter focuses on in their comment (spinner 
dolphins) is the driver for the Agat Bay Mitigation Area, which will 
minimize impacts to spinner dolphins resting in a Bay on the west side 
of Guam where they are known to concentrate. However, as discussed in 
more detail in section I.4.2 of the 2020 MITT FSEIS/OEIS, which NMFS 
reviewed and concurs with, while some of the species that have been 
identified as island-associated residents in Hawaii have been detected 
from nearshore small boat surveys in the Marianas, these same species 
have been detected using offshore areas beyond the 3,500-m isobath in 
offshore surveys or by satellite tags. There is no satellite tag or 
photographic identification data supporting the assertion that the 
populations around the Marianas are resident populations, much less 
that their ranges are spatially limited in a manner that would support 
the consideration of geographic mitigation measures.
    Comment 35: A Commenter recommended that NMFS should consider the 
guidelines for capturing biologically important marine mammal habitat 
in data-poor areas, provided by NMFS' subject-matter experts and 
addressed by the Ninth Circuit Court of Appeals in NRDC v. Pritzker 828 
F.3d 1125 (9th Cir. 2016), as those guidelines are relevant to the 
broader MITT Study Area, much of which is comprised of data-poor, 
offshore areas. These ``White Paper'' guidelines call for: (1) 
Designation as Offshore Biologically Important Areas (OBIAs) of all 
continental shelf waters and waters 100 km seaward of the continental 
slope as biologically important for marine mammals; (2) establishment 
of OBIAs within 100 km of all islands and seamounts that rise within 
500 m of the surface; and (3) nomination as OBIAs of high-productivity 
regions that are not included in the continental shelf, continental 
slope, seamount, and island ecosystems above as biologically important.
    Response: In discussing OBIAs, the commenter references a process 
and set of recommendations that were specifically developed in the 
context of the Navy's SURTASS LFA sonar activities, in which five 
vessels operated primarily in the Pacific Ocean use low frequency 
active sonar only in deep offshore waters to train and search for enemy 
submarines. The geographic area of the SURTASS LFA regulations includes 
the western and central North Pacific Ocean and eastern Indian Ocean 
outside of the territorial seas of foreign nations (generally 12 nmi 
(22 km) from most foreign nations). By referencing designation as 
OBIAs, we assume the Commenter is suggesting restricting active sonar 
(at a minimum) in the areas identified. Below we discuss the 
consideration of these areas for mitigation in the MITT Study Area.
    Regarding recommendations (1) and (2), restricting the Navy's MITT 
activities in these areas is impracticable, as many of the Navy's 
activities specifically necessitate use of the varied bathymetry that 
occurs between the continental slope and 100 km seaward or around 
seamounts, and many can occur only within designated training or 
testing areas that fall within this area.
    The Navy has communicated to NMFS that the MITT Study Area includes 
dedicated range assets, special use airspace, and other infrastructure 
to support training and testing activities that would not be available 
to the Navy should it have to conduct activities beyond the continental 
shelf waters (including a 100 km buffer). Mid-frequency and high-
frequency sonar sources, which are the primary sources used in the MITT 
training and testing activities, have a much smaller propagation range 
than LF sources. Therefore, moving further and further offshore, from 
seamounts, from islands, etc. would result in completely ineffective 
training/testing because the sonar system would not be able to perform 
in locations of the bathymetries required to meet proficiency with 
standoff/buffer distances proposed. Shelf, slope, sea mount, and 
shallow island associated waters are the type of complex training 
environments required by the Navy since those are the types of 
bathymetric conditions that deployed units to the Navy's 7th Fleet will 
be most presented with when operating in the Philippine Sea, South 
China Sea, etc. Therefore, it is impracticable to limit activities in 
the locations recommended by the white paper.
    Also, regarding the 100 km offshore of the slope limitation, 
density data from other regions where more granular survey data is 
available generally indicate that while some species may typically be 
more concentrated in shelf and slope waters, certain mysticete species 
and sperm whales often have higher densities outside of the mitigation 
area the Commenter suggests (100 km beyond the Continental Slope), and 
focusing activities in those areas would shift impacts from more 
coastal species to more pelagic species, making any overall reduction 
in impacts uncertain. Regarding seamounts, while data have shown higher 
species diversity or aggregations of some species at some seamounts 
during certain periods of time (Morato et al., 2008), they also suggest 
that these aggregations are often specific to a seamount or time period 
(i.e., not all seamounts exhibit these aggregations at all times) and, 
further, that marine mammal species are more loosely associated with 
seamounts than other taxa (Pitcher et al., 2007). When this information 
is considered in combination with the fact that no more than a few 
takes of any individual marine mammal are expected throughout the MITT 
Study Area annually, any potential reduction in impacts would be 
limited. For additional information regarding marine mammal use of 
seamounts, see the White Paper Specific Recommendations section of 
NMFS' Final Rule for SURTASS LFA Sonar (84 FR 40132, 40192, August 13, 
2019). Given the lack of evidence supporting the likelihood that this 
approach would provide meaningful reduction of impacts to marine mammal 
species and their habitat in the MITT Study Area, combined with the 
impracticability for Navy implementation, NMFS finds that these 
measures are not warranted beyond the procedural mitigation measures 
that reduce the likelihood of injury or more severe behavioral impacts 
for all species in all areas.
    Regarding restricting Navy activities in areas of high 
productivity, we first refer the reader to our response immediately 
above, which addresses the West Marianas Trench, and further note that 
the Commenter does not identify, and nor is NMFS aware of, any other 
known areas of high productivity within the MITT Study Area. More 
generally, areas of the highest productivity tend to be found in areas 
of high latitude (not found in the MITT Study Area) or near river 
mouths (small boat surveys in the MITT Study Area have already allowed 
for the identification of specifically important nearshore areas for 
marine mammals, which have been designated as geographic mitigation 
areas)

[[Page 46329]]

(Wolverton, 2009). More moderate areas of productivity tend to occupy 
large, and often ephemeral, offshore areas that are difficult to 
consistently define because of interannual spatial and temporal 
variability. Regions of high productivity have the potential to provide 
good foraging habitat for some species of marine mammals, however, 
there is not sufficient data to support the designation of any specific 
area. Further, the fact that no more than a few takes of any individual 
marine mammal are expected throughout the MITT Study Area annually 
suggests that any potential reduction in impacts would be limited. When 
this limited benefit is balanced against the general impracticability 
of restricting Navy training and testing in large portions of the MITT 
Study Area, and given the lack of information to identify an 
appropriate area, NMFS finds that this measure is not warranted beyond 
the procedural mitigation measures that reduce the likelihood of injury 
or more severe behavioral impacts for all species in all areas.
    Comment 36: A Commenter recommends that NMFS determine whether the 
Navy's implementation of geographic mitigation measures at the North 
Guam, Ritidian Point, and Tumon Bay Offshore Areas would be practicable 
and if so, include them as mitigation areas in the final rule. In 
either case, all of the relevant information for North Guam, Ritidian 
Point, and Tumon Bay Offshore Areas must be included in the preamble to 
the final rule.
    Response: NMFS has considered the best available information (which 
for mitigation measures discussed here and below includes both best 
available science and information on practicability) for these 
suggested mitigation areas. The areas of North Guam, Ritidian Point, 
and Tumon Bay Offshore Areas were reviewed as potential mitigation 
areas. While sightings and transits of the area by some species were 
noted in review of available scientific research, there is currently no 
information on specific uses for biologically important life processes 
beyond normal species broad-area occurrence (e.g., the areas are not 
exclusive feeding areas, migration routes, or breeding locations). 
Given this, there is no evidence that limiting operations in these 
areas would reduce impacts on marine mammals, and accordingly, no 
geographic mitigation is warranted, regardless of whether it would be 
practicable.
    Comment 37: A Commenter recommends that NMFS should establish 
mitigation areas for spinner dolphin resting habitat at Bile Bay, Tumon 
Bay, and Double Reef, Guam, and Tanapaq Bay, Saipan.
    Response: NMFS has considered the best available information for 
these suggested mitigation areas. Previously reported spinner dolphin 
high-use areas nearshore at Guam include Bile Bay, Tumon Bay, Double 
Reef, as well as north Agat Bay, and off Merizo (Cocos Lagoon area), 
where these animals congregate during the day to rest (Amesbury et al., 
2001; Eldredge, 1991). More recently, high-use areas have included Agat 
Bay; the Merizo channel, tucked into the several small remote bays 
between Merizo and Facpi Point; Piti Bay; Hagatna; Tumon Bay; and Pugua 
Point (Ligon et al., 2011). During the 2010-2018 small boat surveys in 
the Mariana Islands, there were 157 encounters with pods of spinner 
dolphins (Hill et al., 2019). The approximate distance from shore for 
these encounters was 1 km, indicative of their preference for nearshore 
habitat and prevalence in the MITT Study Area (Hill et al., 2017a; Hill 
et al., 2018b; Hill et al., 2019). As described in Section I.3.3 (Agat 
Bay Nearshore Geographic Mitigation Area) of the 2020 MITT FSEIS/OEIS, 
the nearshore area of Agat Bay represents an area of biological 
importance and is practicable for implementation, and has been included 
in the final rule as a geographic mitigation area for spinner dolphin 
resting behavior. The data suggesting numerous other locations around 
Guam and other islands where resting behavior has been observed or has 
the potential to occur (i.e., the habitat is suitable) indicates that 
no single area is of particular concentration or biological importance. 
See Section 3.4.1.32.2 (Geographic Range and Distribution) of the 2020 
MITT FSEIS/OEIS for more information. Accordingly, specific geographic 
mitigation for these areas, beyond the procedural mitigation measures 
that reduce the likelihood of injury or more severe behavioral impacts 
for spinner dolphins and all other species during all activities, is 
not warranted.
    Comment 38: A Commenter recommends extending the southern boundary 
of the Agat Bay Nearshore Geographic Mitigation Area seaward to the 100 
m depth contour and including a buffer area sufficient to accomplish 
the goal of avoiding mass disruption of spinner dolphins, and expanding 
the same restriction, at minimum, to dipping sonar.
    Response: NMFS has considered the best available information for 
this suggested mitigation area. The current western boundary of the 
Agat Bay Nearshore Geographic Mitigation Area essentially follows the 
100-m isobath except at the southern extent of the area. At its 
northern extent, the area includes deeper waters beyond the 100-m 
isobath to include an area with a cluster of sea turtle sightings. The 
greater number of spinner dolphin sightings may indicate that the 
northern or middle portion of the Agat Bay Nearshore Mitigation Area 
may be of greater importance than the southern portion due to some 
physical or biological features. The point of land at the southern end 
of the Agat Bay Nearshore Mitigation Area is a convenient physical 
feature for defining the area, and as with other sightings data, it is 
reasonable to assume that animals just outside of the boundary of the 
area may be transiting to (or from) the northern portion of the area 
and that areas beyond the boundary do not constitute areas of any 
particular biological significance. The expansion of the area to 
include a buffer at the southern end would not be likely to 
meaningfully further reduce impacts to spinner dolphins and is, 
therefore, not warranted. Dipping sonar, as described in the Detailed 
Description of the Specified Activities section, is used during ASW 
exercises, which occur primarily more than 3 nmi from shore, and would 
especially not occur in areas as shallow as Agat Bay and with a high 
number of small tour boats. As also indicated previously, the vast 
majority of the takes from sonar exposure are related to MF1 sonar, and 
dipping sonar has a significantly lower source level and has not been 
associated with any particular impacts of concern to dolphins. Given 
this, there is no additional protective value to be gained by adding a 
restriction on dipping sonar in this area and it is, therefore, not 
warranted.
    Comment 39: A Commenter recommends that NMFS should establish a 
mitigation area for offshore Agat Bay encompassing the continental 
shelf break and slope and extending out to the 2,000 m depth contour to 
protect this potentially important calving and nursing area for 
endangered sperm whales. Additionally the Commenter also recommends the 
NMFS should establish a second mitigation area for sperm whale calving 
and nursery habitat offshore of Apra Harbor, encompassing the 
continental shelf break and slope and extending out to the 2,000 m 
depth contour.
    Response: NMFS has considered the best available information for 
these suggested mitigation areas. While there were multiple sightings 
of sperm whale calves (not in Agat Bay or concentrated in a particular 
area) during the course of

[[Page 46330]]

the large boat surveys conducted around the Marianas in 2007, the 
recommendation that NMFS should consider an area off Agat Bay as a 
breeding and nursery area for sperm whales seems to be largely based on 
two Associated Press File photographs, taken opportunistically by a 
local photographer, showing a group of three adult sperm whales and a 
calf during an encounter from a commercial dive boat on June 15, 2001, 
``. . . about four miles off the coast of the Agat Marina in Guam'' 
(Bangs, 2001). During the 2010-2018 small boat surveys in the Mariana 
Islands, a total of seven sperm whales were detected over four 
encounters (in 2010, 2013, 2016, and 2018) in a median depth of 
approximately 1,200 m and median distance from shore of approximately 
12 km (Hill et al., 2017a; Hill et al., 2018c; Hill et al., 2018d; Hill 
et al., 2019). Sightings and acoustic monitoring detections recorded 
both before and since 2007 indicate that sperm whales range widely in 
the MITT Study Area with no known areas of concentration in the Mariana 
Islands. Sperm whales are highly nomadic, mobile predators, and the 
available data do not support areas offshore of Agat Bay or Apra Harbor 
as important reproductive areas for sperm whales in the MITT Study 
Area. For instance, a sperm whale with a satellite tracking tag 
attached traveled in deep offshore waters from west of Guam to west of 
Saipan in less than 10 days (Hill et al. 2019). Accordingly, specific 
geographic mitigation in these areas, beyond the procedural mitigation 
measures that reduce the likelihood of injury or more severe behavioral 
impacts for sperm whales and all other species during all activities, 
is not warranted.
    Comment 40: A Commenter recommended that NMFS should protect Cocos 
Lagoon and the continental shelf and slope waters west of Cocos Island 
seaward to the 2,000 m depth contour as an important habitat area for 
multiple species, particularly breeding habitat for a possibly resident 
pygmy killer whale population and resting habitat for spinner dolphin 
at Cocos Island and Lagoon, Guam.
    Response: NMFS has considered the best available information for 
this suggested mitigation area. Like similar deep-water and deep-diving 
species, pygmy killer whales are likely highly mobile in the marine 
environment with no known concentration areas in the Mariana Islands. 
There was only one pygmy killer whale sighting of a group of six 
animals during the 2007 systematic survey of the MITT Study Area 
(Fulling et al., 2011). The sighting occurred near the Mariana Trench, 
south of Guam, where the bottom depth was over 4,413 m. This is 
consistent with the known habitat preference of this species for deep, 
oceanic waters. However, in the Mariana Islands, pygmy killer whale 
sightings close to shore are not unexpected due to deep bathymetry 
surrounding most islands. There is no information on population range 
of pygmy killer whales off Guam (Hill et al., 2019), or any information 
suggesting that the area recommended by the Commenter is of specific 
biological importance such that mitigation measures would result in a 
reduction of impacts. Therefore, consideration of geographic 
mitigation, beyond the procedural mitigation measures that reduce the 
likelihood of injury or more severe behavioral impacts for pygmy killer 
whales and all other species during all activities, is not warranted. 
See Section 3.4.1.26.1 (Geographic Range and Distribution) of the 2020 
MITT FSEIS/OEIS for more information.
    For spinner dolphin habitat, there are numerous other locations 
around Guam and other islands where resting behavior has been observed 
or has the potential to occur (i.e., the habitat is suitable), however, 
the data suggest that no single area, including the area recommended by 
the Commenter, is of particular biological importance (i.e., with the 
predictable regular recurrence of larger pods of resting dolphins seen 
at Agat Bay). See Section 3.4.1.32.2 (Geographic Range and 
Distribution) of the 2020 MITT FSEIS/OEIS for more information. As 
such, a mitigation area here is not likely to meaningfully reduce 
impacts to spinner dolphins and, therefore, consideration of geographic 
mitigation, beyond the procedural mitigation measures that reduce the 
likelihood of injury or more severe behavioral impacts for spinner 
dolphins and all other species during all activities, is not warranted.
    Comment 41: A Commenter recommended that NMFS should designate a 
mitigation area to protect, at minimum, the ten percent ``highest use 
area'' for short-finned pilot whales in core use areas, west of Guam 
and Rota.
    Response: NMFS has considered the best available information for 
this suggested mitigation area. During the 2010-2018 small boat surveys 
in the Mariana Islands, short-finned pilot whale groups were 
encountered on 23 occasions in a median depth of approximately 720 m 
and median distance from shore of approximately 5 km, including one pod 
of 35 individuals off Marpi Reef north of Saipan (Hill et al., 2014; 
Hill et al., 2017a; Hill et al., 2018b; Hill et al., 2018d; Hill et 
al., 2019). Satellite tags deployed on 17 individuals between 2013 and 
2018 suggest multiple areas are used frequently by short-finned pilot 
whales in the Marianas, including but not limited to areas west of Guam 
and Rota (Hill et al., 2018d; Hill et al., 2019). Satellite tags on 
short-finned pilot whales lasting from approximately 9-128 days showed 
that individuals ranged from south at Tumon Bay off Guam to as far 
north as the waters west of Anatahan (Hill et al., 2019). The Commenter 
uses tag data from the movement of eleven individuals to suggest 
probability density contours centered northwest of Guam, however, 
multiple locations of eleven animals are not necessarily representative 
of the distribution of all of the animals in the population. 
Altogether, tag locations and visual detections suggest multiple areas 
of frequent use by short-finned pilot whales in the Mariana Islands and 
do not support that the areas west of Guam and Rota are key areas of 
biological importance for short-finned pilot whales. Accordingly, 
specific geographic mitigation measures, beyond the procedural measures 
that reduce the likelihood of injury or more severe behavioral impacts 
for short-finned pilot whales during all activities, is not warranted.
    Comment 42: A Commenter recommended that NMFS should establish a 
mitigation area to protect important habitat for multiple species of 
marine mammals at Rota Bank, particularly as important habitat for 
spinner and bottlenose dolphins and potential feeding habitat for 
Bryde's whales.
    Response: NMFS has considered the best available information for 
this suggested mitigation area. As discussed in Appendix I (Geographic 
Mitigation Assessment) of the 2020 MITT FSEIS/OEIS, there is 
insufficient evidence to identify Rota Bank as an important area for 
spinner dolphins or bottlenose dolphins and therefore additional 
mitigation beyond the procedural measures that reduce impacts for all 
species is not warranted. The Commenter notes the potentially higher 
relative abundance of spinner dolphins in the area, as well as the 
potential for a genetically distinct population of bottlenose dolphins. 
However, spinner dolphins have also been sighted at multiple other 
locations around the Marianas, including important resting habitat in 
Agat Bay where NMFS has developed a geographic mitigation area, and the 
Commenter includes no information to support why the identification of 
a genetically distinct population of bottlenose dolphins in the 
Marianas would support the

[[Page 46331]]

identification of a mitigation area at Rota Bank. Further, the single 
sighting of a Bryde's whale feeding approximately five years ago does 
not indicate the presence of an established feeding area for the 
species.
    During nine years of surveys from 2010-2018, spinner dolphins were 
only sighted at Rota Bank on two years, 2011 and 2012 (Hill et al., 
2019). More sightings across all years occurred in shallow water less 
than 100 m and within 1 km of land. Bottlenose dolphins, similar to 
spinner dolphins, were only sighted at Rota Bank in 2011 and 2012. 
Tracking of six bottlenose dolphins with attached satellite tags showed 
wide variations in tag locations between northern Guam and Rota (tag 
duration only 3.7-20.5 days). Only four Bryde's whale sightings in 2015 
near Guam or Rota were reported based on small boat surveys from 2010-
2018. Only one of these four sightings was near, although not on, Rota 
Bank. There were no other Bryde's whale sightings near Rota Bank in any 
other year. Accordingly, specific geographic mitigation, beyond the 
procedural measures that reduce the likelihood of injury or more severe 
behavioral impacts for dolphins and all species during all activities, 
is not warranted.
Other Mitigation and Monitoring
    Comment 43: Based on the fact that the Commenter did not see 
reference to the Navy's ongoing Lookout effectiveness study in the 2020 
MITT FSEIS/OEIS and was concerned that the results of this 10-year 
study would not be made available, they recommended that NMFS require 
the Navy to (1) allocate additional resources to the Lookout 
effectiveness study, (2) consult with the University of St. Andrews to 
determine how much additional data is necessary to analyze the data in 
a statistically significant manner, and (3) plan future Lookout 
effectiveness cruises to maximize the potential number of sightings so 
that the study can be completed by the end of 2022.
    Response: NMFS has ensured that the results of the Lookout 
effectiveness study will be made available by including a Term and 
Condition in the ESA Incidental Take Statement associated with this 
rule that requires the Navy to provide a report summarizing the status 
of and/or providing a final assessment on the Navy's Lookout 
Effectiveness Study following the end of Calendar Year (CY) 2021. The 
report must be submitted no later than 90 days after the end of CY2021. 
The report will provide a statistical assessment of the data available 
to date characterizing the effectiveness of Navy Lookouts relative to 
trained marine mammal observers for the purposes of implementing the 
mitigation measures.
    Comment 44: A Commenter recommends that NMFS require the Navy to 
use passive and active acoustic monitoring (such as instrumented 
ranges), whenever practicable, to supplement visual monitoring during 
the implementation of its mitigation measures for all activities that 
could cause injury or mortality beyond those explosive activities for 
which passive acoustic monitoring already was proposed. At the very 
least, the sonobuoys, active sources, and hydrophones used during an 
activity should be monitored for marine mammals.
    Response: The Navy does employ passive acoustic monitoring to 
supplement visual monitoring when practicable to do so (i.e., when 
assets that have passive acoustic monitoring capabilities are already 
participating in the activity). We note, however, that sonobuoys have a 
narrow band that does not overlap with the vocalizations of all marine 
mammals, and there is no bearing or distance on detections based on the 
number and type of devices typically used; therefore it is not possible 
to use these to implement mitigation shutdown procedures. For explosive 
events in which there are no platforms participating that have passive 
acoustic monitoring capabilities, adding passive acoustic monitoring 
capability, either by adding a passive acoustic monitoring device 
(e.g., hydrophone) to a platform already participating in the activity 
or by adding a platform with integrated passive acoustic monitoring 
capabilities to the activity (such as a sonobuoy), for mitigation is 
not practicable. As discussed in Section 5.6.3 (Active and Passive 
Acoustic Monitoring Devices) of the 2020 MITT FSEIS/OEIS, which NMFS 
reviewed and concurs accurately assesses the practicability of 
utilizing additional passive or active acoustic systems for mitigation 
monitoring, there are significant manpower and logistical constraints 
that make constructing and maintaining additional passive acoustic 
monitoring systems or platforms for each training and testing activity 
impracticable. Additionally, diverting platforms that have passive 
acoustic monitoring capability would impact their ability to meet their 
Title 10 requirements and reduce the service life of those systems.
    Regarding the use of instrumented ranges for real-time mitigation, 
the Commenter is correct that the Navy continues to develop the 
technology and capabilities on its Ranges for use in marine mammal 
monitoring, which can be effectively compared to operational 
information after the fact to gain information regarding marine mammal 
response. There is no instrumented range in the MITT Study Area to use. 
Further, the Navy's instrumented ranges were not developed for the 
purpose of mitigation. The manpower and logistical complexity involved 
in detecting and localizing marine mammals in relation to multiple 
fast-moving sound source platforms in order to implement real-time 
mitigation is significant. Although the Navy is continuing to improve 
its capabilities to use range instrumentation to aid in the passive 
acoustic detection of marine mammals, at this time it would not be 
effective or practicable for the Navy to monitor instrumented ranges 
for the purpose of real-time mitigation for the reasons discussed in 
Section 5.6.3 (Active and Passive Acoustic Monitoring Devices) of the 
2020 MITT FSEIS/OEIS.
    Regarding the use of active sonar for mitigation, we note that 
during Surveillance Towed Array Sensor System low-frequency active 
sonar (which is not part of this rulemaking, and uses a high-powered 
low frequency source), the Navy uses a specially designed adjunct high-
frequency marine mammal monitoring active sonar known as ``HF/M3'' to 
mitigate potential impacts. HF/M3 can only be towed at slow speeds 
(significantly slower than those used for ASW and the other training 
and testing uses contemplated for the MITT activities) and operates 
like a fish finder used by commercial and recreational fishermen. 
Installing the HF/M3 adjunct system on the tactical sonar ships used 
during activities in this rule would have implications for safety and 
mission requirements due to impacts on speed and maneuverability. 
Furthermore, installing the system would significantly increase costs 
associated with designing, building, installing, maintaining, and 
manning the equipment. For these reasons, installation of the HF/M3 
system or other adjunct marine mammal monitoring devices as mitigation 
under the rule would be wholly impracticable. Further, NMFS does not 
generally recommend the use of active sonar for mitigation, except in 
certain cases where there is a high likelihood of injury or mortality 
(e.g., gear entanglement) and other mitigations are expected to be less 
effective in mitigating those effects. Active sonar generates 
additional noise with the potential to disrupt marine mammal

[[Page 46332]]

behavior, and is operated continuously during the activity that it is 
intended to mitigate. On the whole, adding this additional stressor is 
not beneficial unless it is expected to offset, in consideration of 
other mitigations already being implemented, a high likelihood or 
amount of injury or mortality. For the Navy's MITT activities, 
mortality is not anticipated, injury is of a small amount of low-level 
PTS, and the mitigation is expected to be effective at minimizing 
impacts. Further, the species most likely to incur a small degree of 
PTS from the Navy's activities are also the species with high frequency 
sensitivity that would be more likely to be behaviorally disturbed by 
the operation of the high frequency active source. For all of these 
reasons, NMFS does not recommend the use of active sonar to mitigate 
the Navy's training and testing activities in the MITT Study Area.
    Comment 45: A Commenter asserted that given the apparent effect of 
the post-model analysis on the agency's mortality estimates--accounting 
perhaps for the drop in expected deaths from 150 (during the previous 
five-year period) to virtually zero--NMFS should have made the Navy's 
approach transparent and explained the rationale for its acceptance of 
that approach. NMFS' failure to do so has prevented the public from 
effectively commenting on NMFS' approach to this issue, in 
contravention of the Administrative Procedure Act, on a matter of 
obvious significance to the agency's core negligible impact findings.
    Response: The Commenter is mistaken, there were no mortalities 
modeled or authorized in the Phase II rulemaking (2015-2020) for the 
MITT Study Area. Please see 80 FR 46112 (Aug. 3, 2015).
    Comment 46: A Commenter recommended that NMFS consider additional 
measures to address mitigation for explosive events at night and during 
periods of low-visibility, either by enhancing the observation 
platforms to include aerial and/or passive acoustic monitoring (such as 
glider use), as has been done here with sinking exercises, or by 
restricting events to particular Beaufort sea states (depending on 
likely species presence and practicability). Another Commenter 
complains that NMFS has not required aerial or passive acoustic 
monitoring as mandatory mitigation, appears unwilling to restrict 
operations in low-visibility conditions, and has set safety-zone bounds 
that are inadequate to protect high-frequency cetaceans even from PTS.
    Response: As described in Section 5.6.2 (Explosives) of the 2020 
MITT FSEIS/OEIS, when assessing and developing mitigation, NMFS and the 
Navy considered reducing the number and size of explosives and limiting 
the locations and time of day of explosive training and testing in the 
MITT Study Area. The locations and timing of the training and testing 
activities that use explosives vary throughout the MITT Study Area 
based on range scheduling, mission requirements, testing program 
requirements, and standard operating procedures for safety and mission 
success. Although activities using explosives typically occur during 
daytime for safety reasons, it is impractical for the Navy to prohibit 
every type of explosive activity at night or during low visibility 
conditions or during different Beaufort sea states. Doing so would 
diminish activity realism, which would impede the ability for Navy 
Sailors to train and become proficient in using explosive weapons 
systems (which would result in a significant risk to personnel safety 
during military missions and combat operations), and would impede the 
Navy's ability to certify forces to deploy to meet national security 
needs.
    Passive acoustic devices, whether vessel-deployed or using research 
sensors on gliders or other devices, can serve as queuing information 
that vocalizing marine mammals could be in the vicinity. Passive 
acoustic detection does not account for individuals not vocalizing. 
Navy surface ships train to localize submarines, not marine mammals. 
Some aviation assets deploying ordnance do not have concurrent passive 
acoustic sensors. Furthermore, Navy funded civilian passive acoustic 
sensors do not report in real-time. Instead, a glider is set on a 
certain path or floating/bottom-mounted sensor deployed. The sensor has 
to then be retrieved often many months after deployment (1-8 months), 
data is sent back to the laboratory, and then subsequently analyzed. 
Combined with lack of localization, gliders with passive acoustic 
sensors are therefore not suitable for mitigation. Further, a SINKEX is 
a highly scripted event that due to its complexity has additional 
assets involved that are not practicable to bring to bear in all the 
smaller types of training and testing scenarios.
    The Navy does employ passive acoustic monitoring when practicable 
to do so (i.e., when assets that have passive acoustic monitoring 
capabilities are already participating in the activity) and several of 
the procedural mitigation measures reflect this, but many platforms do 
not have passive acoustic monitoring capabilities. Adding a passive 
acoustic monitoring capability (either by adding a passive acoustic 
monitoring device (e.g., hydrophone) to a platform already 
participating in the activity, or by adding a platform with integrated 
passive acoustic monitoring capabilities to the activity, such as a 
sonobuoy) for mitigation is not practicable. As discussed in Section 
5.6.3 (Active and Passive Acoustic Monitoring Devices) of the 2020 MITT 
FSEIS/OEIS, there are significant manpower and logistical constraints 
that make constructing and maintaining additional passive acoustic 
monitoring systems or platforms for each training and testing activity 
impracticable. The Navy is required to implement pre-event observation 
mitigation, as well as post-event observation when practical, for all 
in-water explosive events. If there are other platforms participating 
in these events and in the vicinity of the detonation area, they will 
also visually observe this area as part of the mitigation team.
    The Mitigation Section (Section 5) of the 2020 MITT FSEIS/OEIS 
includes a full analysis discussion of the mitigation measures that the 
Navy will implement, as well as those that have been considered but 
eliminated, including potential measures that have been raised by NMFS 
or the public in the past. The Navy has explained that training and 
testing in both good visibility (e.g., daylight, favorable weather 
conditions) and low visibility (e.g., nighttime, inclement weather 
conditions) is vital because environmental differences between day and 
night and varying weather conditions affect sound propagation and the 
detection capabilities of sonar. Temperature layers that move up and 
down in the water column and ambient noise levels can vary 
significantly between night and day. This affects sound propagation and 
could affect how sonar systems function and are operated. While some 
small reduction in the probability or severity of impacts could result 
from the implementation of this measure, it would not be practicable 
for the Navy to restrict operations in low visibility and the measure 
is not, therefore, warranted.
    Regarding the safety zones for high frequency specialists, as the 
Commenter notes, for some sources the zone in which PTS could be 
accrued is larger than the mitigation zones. Because of the lower 
injury thresholds for high frequency specialists, the zones within 
which these species may incur PTS are significantly larger than other 
groups, and for some of the louder or more powerful sources, the injury 
zones are larger than can be effectively monitored

[[Page 46333]]

or practicably mitigated at distances beyond the established shutdown 
zones. In all cases, the required exclusion zones will prevent injury 
in the area closer to the source, thus alleviating some Level A 
harassment and preventing more intense or longer duration exposures 
that would be likely to have more severe impacts, and the small number 
remaining of anticipated PTS has been evaluated in the negligible 
impact analysis and appropriately authorized. In addition to the fact 
that observance and implementation of larger mitigation zones is 
impracticable, we also note that Navy Lookouts do not differentiate 
species and therefore it would not be possible to effectively implement 
a larger shutdown zone that only applied to the two high frequency 
specialists (dwarf and pygmy sperm whales), especially at the distances 
at which this differential mitigation would need to apply (beyond the 
standard zones).
    Comment 47: A Commenter recommended that sonar signals might be 
modified to reduce the level of impact at the source. Mitigating active 
sonar impacts might be achieved by employing down-sweeps with harmonics 
or by reducing the level of side bands (or harmonics). The Commenter 
strongly recommended that NMFS require and set a timeline for this 
research within the context of the present rulemaking.
    Response: The Commenter notes that NOAA's Ocean Noise Strategy 
Roadmap puts an emphasis on source modification and habitat 
modification as an important means for reducing impacts, however, where 
the modification of sources is discussed, the focus of the Roadmap is 
on modifying technologies for activities in which low frequency, 
broadband sound (which contribute far more significantly to increased 
chronic noise levels) is incidental to the activity (e.g., maritime 
traffic). As described in the 2020 MITT FSEIS/OEIS, at this time, the 
science on the differences in potential impacts of up or down sweeps of 
the sonar signal (e.g., different behavioral reactions) is extremely 
limited and requires further development before a determination of 
potential mitigation effectiveness can be made. There is data on 
behavioral responses of a few captive harbor porpoises to varying 
signals. Although this very limited data set suggests up or down sweeps 
of the sonar signal may result in different reactions by harbor 
porpoises in certain circumstances, the author of those studies 
highlights the fact that different species respond to signals with 
varying characteristics in a number of ways. In fact, the same signals 
cited here were also played to harbor seals, and their responses were 
different from the harbor porpoises. Furthermore, harmonics in a signal 
result from a high-intensity signal being detected in close proximity; 
they could be artificially removed for a captive study, but cannot be 
whitened in the open ocean. Active sonar signals are designed 
explicitly to provide optimum performance at detecting underwater 
objects (e.g., submarines) in a variety of acoustic environments. If 
future studies indicate that modifying active sonar signals could be an 
effective mitigation approach, then NMFS with the Navy will investigate 
if and how the mitigation would affect the sonar's performance and how 
that mitigation may be applied in future authorizations, but currently 
NMFS does not have a set timeline for this research and how it may be 
applied to future rulemakings.
    Comment 48: A Commenter recommends that NMFS should consider 
requiring the Navy to employ thermal detection in optimal conditions, 
or, alternatively, require the establishment of a pilot program for 
thermal detection, with annual review under the adaptive management 
system. According to the 2019 MITT DSEIS/OEIS, the Navy ``plans to 
continue researching thermal detection technology to determine their 
effectiveness and compatibility with Navy applications.''
    Response: Thermal detection systems are more useful for detecting 
marine mammals in some marine environments than others. Current 
technologies have limitations regarding water temperature and survey 
conditions (e.g., rain, fog, sea state, glare, ambient brightness), for 
which further effectiveness studies are required. Thermal detection 
systems are generally thought to be most effective in cold 
environments, which have a large temperature differential between an 
animal's temperature and the environment. Current thermal detection 
systems have proven more effective at detecting large whale blows than 
the bodies of small animals, particularly at a distance. The 
effectiveness of current technologies has not been demonstrated for 
small marine mammals. Research to better understand, and improve, 
thermal technology continues, as described below.
    The Navy has been investigating the use of thermal detection 
systems with automated marine mammal detection algorithms for future 
mitigation during training and testing, including on autonomous 
platforms. Thermal detection technology being researched by the Navy, 
which is largely based on existing foreign military grade hardware, is 
designed to allow observers and eventually automated software to detect 
the difference in temperature between a surfaced marine mammal (i.e., 
the body or blow of a whale) and the environment (i.e., the water and 
air). Although thermal detection may be reliable in some applications 
and environments, the current technologies are limited by their: (1) 
Low sensor resolution and a narrow fields of view, (2) reduced 
performance in certain environmental conditions, (3) inability to 
detect certain animal characteristics and behaviors, and (4) high cost 
and uncertain long-term reliability.
    Thermal detection systems for military applications are deployed on 
various Department of Defense (DoD) platforms. These systems were 
initially developed for night time targeting and object detection 
(e.g., a boat, vehicle, or people). Existing specialized DoD infrared/
thermal capabilities on Navy aircraft and surface ships are designed 
for fine-scale targeting. Viewing arcs of these thermal systems are 
narrow and focused on a target area. Furthermore, sensors are typically 
used only in select training events, not optimized for marine mammal 
detection, and have a limited lifespan before requiring expensive 
replacement. Some sensor elements can cost upward of $300,000 to 
$500,000 per device, so their use is predicated on a distinct military 
need.
    One example of trying to use existing DoD thermal systems is being 
proposed by the U.S. Air Force. The Air Force agreed to attempt to use 
specialized U.S. Air Force aircraft with military thermal detection 
systems for marine mammal detection and mitigation during a limited at-
sea testing event. It should be noted, however, these systems are 
specifically designed for and integrated into a small number of U.S. 
Air Force aircraft and cannot be added or effectively transferred 
universally to Navy aircraft. The effectiveness remains unknown in 
using a standard DoD thermal system for the detection of marine mammals 
without the addition of customized system-specific computer software to 
provide critical reliability (enhanced detection, cueing for an 
operator, reduced false positive, etc.)
    Current DoD thermal sensors are not always optimized for marine 
mammal detections versus object detection, nor do these systems have 
the automated marine mammal detection algorithms the Navy is testing 
via its ongoing research program. The combination of thermal technology 
and automated algorithms are still undergoing demonstration and 
validation under Navy funding.

[[Page 46334]]

    Thermal detection systems specifically for marine mammal detection 
have not been sufficiently studied both in terms of their effectiveness 
within the environmental conditions found in the MITT Study Area and 
their compatibility with Navy training and testing (i.e., polar waters 
vs. temperate waters). The effectiveness of even the most advanced 
thermal detection systems with technological designs specific to marine 
mammal surveys is highly dependent on environmental conditions, animal 
characteristics, and animal behaviors. At this time, thermal detection 
systems have not been proven to be more effective than, or equally 
effective as, traditional techniques currently employed by the Navy to 
observe for marine mammals (i.e., naked-eye scanning, hand-held 
binoculars, high-powered binoculars mounted on a ship deck). The use of 
thermal detection systems instead of traditional techniques would 
compromise the Navy's ability to observe for marine mammals within its 
mitigation zones in the range of environmental conditions found 
throughout the MITT Study Area. Furthermore, thermal detection systems 
are designed to detect marine mammals and do not have the capability to 
detect other resources for which the Navy is required to implement 
mitigation, including sea turtles. Focusing on thermal detection 
systems could also provide a distraction from and compromise the Navy's 
ability to implement its established observation and mitigation 
requirements. The mitigation measures discussed in the Mitigation 
Measures section include the maximum number of Lookouts the Navy can 
assign to each activity based on available manpower and resources; 
therefore, it would be impractical to add personnel to serve as 
additional Lookouts. For example, the Navy does not have available 
manpower to add Lookouts to use thermal detection systems in tandem 
with existing Lookouts who are using traditional observation 
techniques.
    The Defense Advanced Research Projects Agency funded six initial 
studies to test and evaluate infrared-based thermal detection 
technologies and algorithms to automatically detect marine mammals on 
an unmanned surface vehicle. Based on the outcome of these initial 
studies, the Navy is pursuing additional follow-on research efforts. 
Additional studies are currently being planned for 2020+ but additional 
information on the exact timing and scope of these studies is not 
currently available (still in the development stage).
    The Office of Naval Research Marine Mammals and Biology program 
also funded a project (2013-2019) to test the thermal limits of 
infrared-based automatic whale detection technology. That project 
focused on capturing whale spouts at two different locations featuring 
subtropical and tropical water temperatures, optimizing detector/
classifier performance on the collected data, and testing system 
performance by comparing system detections with concurrent visual 
observations. Results indicated that thermal detection systems in 
subtropical and tropical waters can be a valuable addition to marine 
mammal surveys within a certain distance from the observation platform 
(e.g., during seismic surveys, vessel movements), but have challenges 
associated with false positive detections of waves and birds (Boebel, 
2017). While Zitterbart et al. (2020) reported on the results of land-
based thermal imaging of passing whales, their conclusion was that 
thermal technology under the right conditions and from land can detect 
a whale within 3 km although there could also be lots of false 
positives, especially if there are birds, boats, and breaking waves at 
sea. Thermal detection systems exhibit varying degrees of false 
positive detections (i.e., incorrect notifications) due in part to 
their low sensor resolution and reduced performance in certain 
environmental conditions. False positive detections may incorrectly 
identify other features (e.g., birds, waves, boats) as marine mammals. 
In one study, a false positive rate approaching one incorrect 
notification per 4 min of observation was noted.
    The Navy plans to continue researching thermal detection systems 
for marine mammal detection to determine their effectiveness and 
compatibility with Navy applications. If the technology matures to the 
state where thermal detection is determined to be an effective 
mitigation tool during training and testing, NMFS and the Navy will 
assess the practicability of using the technology during training and 
testing events and retrofitting the Navy's observation platforms with 
thermal detection devices. The assessment will include an evaluation of 
the budget and acquisition process (including costs associated with 
designing, building, installing, maintaining, and manning the 
equipment); logistical and physical considerations for device 
installment, repair, and replacement (e.g., conducting engineering 
studies to ensure there is no electronic or power interference with 
existing shipboard systems); manpower and resource considerations for 
training personnel to effectively operate the equipment; and 
considerations of potential security and classification issues. New 
system integration on Navy assets can entail up to 5 to 10 years of 
effort to account for acquisition, engineering studies, and development 
and execution of systems training. The Navy will provide information to 
NMFS about the status and findings of Navy-funded thermal detection 
studies and any associated practicability assessments at the annual 
adaptive management meetings.
    Evidence regarding the current state of this technology does not 
support the assertion that the addition of these devices would 
meaningfully increase detection of marine mammals beyond the current 
rate (especially given the narrow field of view of this equipment and 
the fact that a Lookout cannot use standard equipment when using the 
thermal detection equipment) and, further, modification of standard 
Navy equipment, training, and protocols would be required to integrate 
the use of any such new equipment, which would incur significant cost. 
At this time, requiring thermal equipment is not warranted given the 
prohibitive cost and the uncertain benefit (i.e., reduction of impacts) 
to marine mammals. Likewise requiring the establishment of a pilot 
program is not appropriate. However, as noted above, the Navy continues 
to support research and technology development to improve this 
technology for potential future use.
    Comment 49: A Commenter stated that the proposed rule does not 
contain any indication that a practicability analysis was conducted, 
nor does it prescribe any speed reduction measure. They ask that NMFS 
conduct a practicability analysis and implement vessel speed reduction 
in (at minimum) the Marpi Reef and Chalan Kanoa Reef Mitigation Areas 
and other areas of importance to humpback whales, as was done for the 
North Atlantic right whale in the AFTT Study Area. They further 
recommended that the agency require the Navy to collect and report data 
on ship speed to allow for objective evaluation by NMFS of ship-strike 
risk, of harassment resulting from vessel activity, and of the 
potential benefit of additional speed-focused mitigation measures.
    Response: NMFS discussed its evaluation of requiring vessel speed 
restrictions in Marpi Reef and Chalan Kanoa Reef Geographic Mitigation 
Areas in Comment 17 above. NMFS and the Navy conducted an operational 
analysis of potential mitigation areas throughout

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the entire MITT Study Area to consider a wide range of mitigation 
options, including but not limited to vessel speed restrictions. Navy 
ships transit at speeds that are optimal for fuel conservation or to 
meet operational requirements. In our assessment of potential 
mitigation, NMFS and the Navy have considered implementing vessel speed 
restrictions. However, as described in Section 5 (Mitigation), Section 
5.3.4.1 (Vessel Movement) of the 2020 MITT FSEIS/OEIS, including vessel 
speed restrictions would be impracticable due to implications for 
safety (the ability to avoid potential hazards), sustainability 
(maintain readiness), and the Navy's ability to continue meeting its 
Title 10 requirements to successfully accomplish military readiness 
objectives. Any vessel speed restrictions would prevent vessel 
operators from gaining skill proficiency, would prevent the Navy from 
properly testing vessel capabilities, and/or would increase the time on 
station during training or testing activities as required to achieve 
skill proficiency or properly test vessel capabilities, which would 
significantly increase fuel consumption. NMFS thoroughly reviewed and 
considered the information and analysis in the 2020 MITT FSEIS/OEIS, 
and concurred with the Navy's determination that vessel speed 
restrictions are impracticable. As discussed in the Mitigation Measures 
section of this rule, the Navy will implement mitigation to avoid 
vessel strikes throughout the Study Area. Given the impracticability of 
vessel speed restrictions combined with the fact that vessel strike is 
not anticipated in the MITT Study Area and that the required mitigation 
for vessel movement will already minimize any potential for ship 
strike, NMFS finds vessel speed reductions are not warranted.
    As required through the Navy's Notification and Reporting Plan 
(Vessel Strike section), Navy vessels are required to report extensive 
information, including ship speed, pursuant to any marine mammal vessel 
strikes. Therefore, the data required for ship strike analysis 
discussed in the comment is already being collected. Any additional 
data collection requirement would create an unnecessary burden on the 
Navy.
    Regarding vessel noise from Navy ships, Navy vessels are 
intentionally designed to be quieter than civilian vessels, and given 
that adverse impacts from vessel noise are not anticipated to result 
from Navy activities (see the Potential Effects of Specified Activities 
on Marine Mammals and Their Habitat section in the proposed rule), 
there is no anticipated harassment caused by vessel activity and 
therefore no need to collect and report data on ship speed for this 
purpose.
    Comment 50: A Commenter recommended that NMFS should consider a 
compensatory mitigation scheme to help improve the conservation status 
or habitat of affected populations. NMFS should consider requiring 
compensatory mitigation for the adverse impacts of the Navy's activity 
on marine mammals and their habitat that cannot be prevented or 
mitigated.
    Response: Compensatory mitigation is not required under the MMPA. 
Instead, authorizations include means of effecting the least 
practicable adverse impact from the activities on the affected species 
or stocks and their habitat, which this rule has done through the 
required procedural and geographic area mitigation measures.
    For years, the Navy has implemented a broad and comprehensive range 
of measures in the MITT Study Area to mitigate potential impacts to 
marine mammals from its training and testing activities. In addition, 
from 2010 and ongoing, the Navy has funded extensive marine mammal 
occurrence studies within the Mariana Islands. As described in this 
rule, NMFS and the Navy have expanded these measures further where 
practicable. In addition to the mitigation and monitoring measures 
required under this rule and past MMPA incidental take authorizations, 
the Navy engages in an extensive spectrum of other activities that 
greatly benefit marine species in a more general manner that is not 
necessarily tied to just military readiness activities. As noted in 
Section 3, Section 3.0.1.1 (Marine Species Monitoring and Research 
Programs) of the 2020 MITT FSEIS/OEIS, the Navy provides extensive 
investment for research programs in basic and applied research. The 
Navy is one of the largest sources of funding for marine mammal 
research in the world, which has greatly enhanced the scientific 
community's understanding of marine species more generally. The Navy's 
support of marine mammal research includes: Marine mammal detection, 
including the development and testing of new autonomous hardware 
platforms and signal processing algorithms for detection, 
classification, and localization of marine mammals; improvements in 
density information and development of abundance models of marine 
mammals; and advancements in the understanding and characterization of 
the behavioral, physiological (hearing and stress response), and 
potentially population-level consequences of sound exposure on marine 
life. Importantly, the Commenter did not recommend any specific 
measures, rendering it impossible to consider its recommendation at a 
broader level.
    Comment 51: A Commenter recommends that NMFS require that the Navy 
continue to conduct long-term monitoring and prioritize Navy research 
projects that aim to quantify the impact of training and testing 
activities at the individual, and ultimately, population-level. The 
Commenter recommended individual-level behavioral-response studies, 
such as focal follows and tagging using DTAGs, carried out before, 
during, and after Navy operations, that can provide important insights 
for these species and stocks. The Commenter recommended studies be 
prioritized that further characterize the suite of vocalizations 
related to social interaction, such as studies using DTAGs that further 
characterize social communications between individuals of a species or 
stock, including between mothers and calves. The Commenter recommends 
the use of unmanned aerial vehicles for surveying marine species and to 
provide a less invasive approach to undertaking focal follows. Imagery 
from unmanned aerial vehicles can also be used to assess body condition 
and, in some cases, health of individuals. The Commenter recommended 
that NMFS require the Navy to use these technologies for assessing 
marine mammal behavior (e.g., swim speed and direction, group cohesion) 
before, during, and after Navy training and testing. Additionally, the 
Commenter recommended that the Navy support studies to explore how 
these technologies can be used to assess body condition, as this can 
provide an important indication of energy budget and health, which can 
inform the assessment of population-level impacts.
    Response: First, the Navy is pursuing many of the topics that the 
Commenter identifies, either through the monitoring required under the 
MMPA or monitoring under the ESA, or through other Navy-funded research 
programs (ONR and LMR). We are confident that the monitoring conducted 
by the Navy satisfies the requirements of the MMPA. A list of the 
monitoring studies that the Navy will be conducting under this rule is 
at the end of the Monitoring section of this final rule.
    Broadly speaking, in order to ensure that the monitoring the Navy 
conducts satisfies the requirements of the MMPA, NMFS works closely 
with the Navy in the identification of monitoring priorities and the 
selection of projects to

[[Page 46336]]

conduct, continue, modify, and/or stop through the Adaptive Management 
process, which includes annual review and debriefs by all scientists 
conducting studies pursuant to the MMPA authorization. The process NMFS 
and the Navy have developed allows for comprehensive and timely input 
from NMFS, the Navy, the Marine Mammal Commission, and researchers 
conducting monitoring under the Navy rule, which is based on rigorous 
reporting out from the Navy and the researchers doing the work.
    With extensive input from NMFS, the Navy established the Strategic 
Planning Process for Marine Species Monitoring to help structure the 
evaluation and prioritization of projects for funding. The Monitoring 
section of this rule provides an overview of this Strategic Planning 
Process. More detail, including the current intermediate scientific 
objectives, is available in section 5 (Mitigation), Section 5.1.2.2.1.3 
(Strategic Planning Process) of the 2020 MITT FSEIS/OEIS and on the 
monitoring portal as well as in the Strategic Planning Process report. 
The Navy's evaluation and prioritization process is driven largely by a 
standard set of criteria that help the internal steering committee 
evaluate how well a potential project would address the primary 
objectives of the monitoring program. Given that the Navy's Monitoring 
Program applies to all of the Navy's major Training and Testing 
activities and, thereby, spans multiple regions and Study Areas to 
encompass consideration of the entire U.S. EEZ and beyond, one of the 
key components of the prioritization process is to focus monitoring in 
a manner that fills regionally-specific data gaps, where possible 
(e.g., more limited basic marine mammal distribution data in the MITT 
Study Area), and also takes advantage of regionally-available assets 
(e.g., instrumented ranges in the HSTT Study Area). NMFS has 
opportunities to provide input regarding the Navy's intermediate 
scientific objectives as well as to provide feedback on individual 
projects through the annual program review meeting and annual report. 
For additional information, please visit: https://www.navymarinespeciesmonitoring.us/about/strategic-planning-process/.
    Details on the Navy's involvement with future research will 
continue to be developed and refined by the Navy and NMFS through the 
consultation and adaptive management processes, which regularly 
consider and evaluate the development and use of new science and 
technologies for Navy applications. Further, the Navy also works with 
NMFS to target and prioritize data needs that are more appropriately 
addressed through Navy research programs, such as the Office of Naval 
Research and Living Marine Resources programs. The Navy has indicated 
that it will continue to be a leader in funding of research to better 
understand the potential impacts of Navy training and testing 
activities and to operate with the least possible impacts while meeting 
training and testing requirements. Some of the efforts the Navy is 
leading or has recently completed are described below.
    (1) Individual-level behavioral-response studies--There are no ONR 
or LMR behavioral response studies in the MITT Study Area. The Mariana 
Islands are too remote for many of the mainland U.S. and international 
researchers. There is also insufficient background information or 
infrastructure to support something as specific as a behavioral 
response study. For example, Navy instrumented ranges in the HSTT Study 
Area and the Bahamas are critical in providing consistent beaked whale 
detections which allow researchers in small boats to more efficiently 
locate detected whales to apply satellite tracking tags. However, many 
of the studies on species-specific reactions are likely to be 
applicable across geographic boundaries (e.g., Cuvier's beaked whale 
studies in the HSTT Study Area).
    (2) Tags and other detection technologies to characterize social 
communication between individuals of a species or stock, including 
mothers and calves--DTAGs are just one example of animal movement and 
acoustics tag. From the Navy's Office of Naval Research and Living 
Marine Resource programs, Navy funding is being used to improve a suite 
of marine mammal tags to increase attachment times, improve data being 
collected, and improve data satellite transmission. The Navy has funded 
a variety of projects that are collecting data that can be used to 
study social interactions amongst individuals. For example, as of July 
2020 the following studies are currently being funded:

 Assessing performance and effects of new integrated 
transdermal large whale satellite tags 2018-2021 (Organization: Marine 
Ecology and Telemetry Research)
 Autonomous Floating Acoustic Array and Tags for Cue Rate 
Estimation 2019-2020 (Organization: Texas A&M University Galveston)
 Development of the next generation automatic surface whale 
detection system for marine mammal mitigation and distribution 
estimation 2019-2021 (Organization: Woods Hole Oceanographic 
Institution)
 High Fidelity Acoustic and Fine-scale Movement Tags 2016-2020 
(Organization: University of Michigan)
 Improved Tag Attachment System for Remotely-deployed Medium-
term Cetacean Tags 2019-2023 (Organization: Marine Ecology and 
Telemetry Research)
 Next generation sound and movement tags for behavioral studies 
on whales 2016-2020 (Organization: University of St. Andrews)
 On-board calculation and telemetry of the body condition of 
individual marine mammals 2017-2021 (Organization: University of St. 
Andrews, Sea Mammal Research Unit)
 The wide-band detection and classification system 2018-2020 
(Organization: Woods Hole Oceanographic Institution)

    (3) Unmanned Aerial Vehicles to assess marine mammal behavior 
(e.g., swim speed and direction, group cohesion) before, during, and 
after Navy training and testing activities--Studies that use unmanned 
aerial vehicles to assess marine mammal behaviors and body condition 
are being funded by the Office of Naval Research Marine Mammals and 
Biology program. Although the technology shows promise (as reviewed by 
Verfuss et al., 2019), the field limitations associated with the use of 
this technology have hindered its useful application in behavioral 
response studies in association with Navy training and testing events. 
For safety, research vessels cannot remain in close proximity to Navy 
vessels during Navy training or testing events, so battery life of the 
unmanned aerial vehicles has been an issue. However, as the technology 
improves, the Navy will continue to assess the applicability of this 
technology for the Navy's research and monitoring programs. An example 
project that the Navy already addressed is integrating remote sensing 
methods to measure baseline behavior and responses of social delphinids 
to Navy sonar 2016-2019 (Organization: Southall Environmental 
Associates Inc.).
    (4) Modeling methods that could provide indicators of population-
level effects--NMFS asked the Navy to expand funding to explore the 
utility of other, simpler modeling methods that could provide at least 
an indicator of population-level effects, even if each of the 
behavioral and physiological mechanisms are not fully characterized. 
The Office of Naval Research Marine Mammals and Biology program has 
invested in the Population

[[Page 46337]]

Consequences of Disturbance (PCoD) model, which provides a theoretical 
framework and the types of data that would be needed to assess 
population level impacts. Although the process is complicated and many 
species are data poor, this work has provided a foundation for the type 
of data that is needed. Therefore, in the future, the relevant data 
pieces that are needed for improving the analytical approaches for 
population level consequences resulting from disturbances will be 
collected during projects funded by the Navy's marine species 
monitoring program. However, currently, PCoD models are dependent on 
too many unknown factors to produce a reliable answer for most species 
and activity types, and further work is needed (and underway) to 
develop a more broadly applicable generalized construct that can be 
used in an impact assessment.
    As discussed in the Monitoring section of the final rule, the 
Navy's marine species monitoring program typically supports 10-15 
projects in the Pacific at any given time. Current projects cover a 
range of species and topics from collecting baseline data on occurrence 
and distribution, to tracking whales, to conducting behavioral response 
studies on beaked whales and pilot whales. The Navy's marine species 
monitoring web portal provides details on past and current monitoring 
projects, including technical reports, publications, presentations, and 
access to available data and can be found at: https://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/.
    In summary, NMFS and the Navy work closely together to prioritize, 
review, and adaptively manage the extensive suite of monitoring that 
the Navy conducts in order to ensure that it satisfies the MMPA 
requirements. NMFS has laid out a broad set of goals that are 
appropriate for any entity authorized under the MMPA to pursue, and 
then we have worked with the Navy to manage their projects to best 
target the most appropriate goals given their activities, impacts, and 
assets in the MITT Study Area. Given the scale of the MITT Study Area 
and the variety of activities conducted, there are many possible 
combinations of projects that could satisfy the MMPA standard for the 
rule. The Commenter has recommended more and/or different monitoring 
than NMFS is requiring and the Navy is conducting or currently plans to 
conduct, but has in no way demonstrated that the monitoring currently 
being conducted does not satisfy the MMPA standard. NMFS appreciates 
the Commenter's input, and will consider it, as appropriate, in the 
context of our adaptive management process, but is not recommending any 
changes at this time.
    Comment 52: A Commenter recommended that the Navy conduct research 
and documentation of the residency of populations of spinner dolphins 
on Guam and impacts of the training to them. The Commenter states that 
these populations may particularly be impacted by the mine explosion 
training in areas at Agat and Asan. The Commenter recommends that the 
Navy provide better information on the impacts of the explosions on 
these populations before implementing the training at those sites. The 
Commenter recognizes and supports that an area frequented by the Agat 
spinner dolphins is identified as a mitigation area (mostly in National 
Park Service managed waters) because of their presence.
    Response: The Navy has been funding the majority of marine species 
research and surveys in the Mariana Islands. Over a nine year period 
from 2010-2018 during the Navy-funded small boat surveys in the Mariana 
Islands, 22,488 km of on-effort surveys were conducted with 157 
encounters with pods of spinner dolphins (Hill et al., 2019). The 
approximate distance from shore for these encounters was 1 km, 
indicative of their preference for nearshore habitat and prevalence in 
the MITT Study Area (Hill et al., 2017a; Hill et al., 2018b; Hill et 
al., 2019). In addition to visual sightings, a photo-identification 
catalog for spinner dolphins was developed as well as biopsies taken 
for genetic analysis (Hill et al., 2019). The Navy has also contributed 
significant funding for NMFS' Pacific Marine Assessment Program for 
Protected Species (PACMAPPS) program. PACMAPPS is a partnership among 
Federal agencies to conduct surveys to assess the abundance of multiple 
species and their ecosystems (NOAA Fisheries, U.S. Navy, Bureau of 
Ocean Energy Management, U.S. Fish and Wildlife Service). With Navy 
funding, NMFS will conduct a 60-day marine mammal survey within the 
Mariana Island EEZ in the spring and summer of 2021. Future Mariana 
Islands marine mammal surveys after PACMAPPs will be funded by NMFS' 
Pacific Islands Fisheries Science Center. For an extensive discussion 
of spinner dolphin sightings near Agat Bay, see Section I.3.3.1.1.1 of 
the 2020 MITT FSEIS/OEIS.
    Regarding the impacts of explosives, activities, including mine 
countermeasure activities at the Agat Bay and Apra Harbor sites, were 
modeled to estimate impacts on marine mammals from explosives. No 
mortalities of any marine mammals are predicted. Asan is not identified 
as an underwater detonation area. Further, although called Agat Bay 
Mine Neutralization Site, the actual detonation site is in waters 
deeper than 1,000 m and over 8 km west of the shallow water Agat Bay 
Nearshore Geographic Mitigation Area (see Figure 3 of this rule) and 
therefore there is not a potential for overlap of explosive activities 
at the Agat Bay Mine Neutralization Site with spinner dolphin resting. 
Additionally, the Navy uses the Agat Bay Mine Neutralization Site for 
smaller charge weight mine neutralization activities that are episodic 
with large temporal variation between successive events. In 
consideration of the mine neutralization mitigations established for 
all marine mammals (see the Procedural Mitigation subsection in the 
Mitigation Measures section of the rule) and the distance between the 
actual detonation site and the shallow water spinner dolphin habitat in 
Agat Bay, the effects to spinner dolphins will be minimal.

Negligible Impact Determination

    Comment 53: A Commenter asserts that most of NMFS' discussion 
consists, once again, of generalized statements meant to suggest why 
the estimated levels of take will not result in greater than negligible 
impacts on marine mammals. For example, NMFS discounts the potential 
for population-level impacts by asserting that based on the nature of 
the Navy activities and the movement patterns of marine mammals, it is 
unlikely any particular subset would be taken over more than a few 
sequential days 85 FR 5875. Yet NMFS presents no details of the Navy's 
operations in support of this position. Further a Commenter says that 
the proposed rule makes no attempt to apply any of the methods used by 
the marine mammal research community to assess population-level harm. 
Such methods, involving quantitative or detailed qualitative 
assessment, include but are not limited to the use of reasonable 
proxies for population-level impact; models of masking effects; 
energetic models, such as on foraging success; or quantitative 
assessments of chronic noise or stress. The Commenter asserts that the 
agency does not consider the effects of these more frequent exposures 
on individual and population fitness, nor, again, does NMFS provide 
more than general statements discounting the significance of the 
expected take.
    Response: NMFS fully considered the potential for aggregate effects 
from all Navy activities and the Commenter

[[Page 46338]]

offers no evidence to support the assertion that any individual marine 
mammals, of any species, would be subject to ``frequent exposures.'' 
NMFS has explained in detail in the proposed rule and again in this 
final rule how the estimated takes were calculated for marine mammals, 
and then how the large size of the Study Area across which activities 
may be distributed (and the ASW activities utilizing MF1 sonar, which 
account for the majority of the takes may occur anywhere in the Study 
Area and predominantly more than 3 nmi from shore) combined with the 
comparatively small number of takes as compared to the abundance of any 
species in the area does not support that any individuals would likely 
be taken over more than a few non-sequential days. We also consider 
UMEs (where applicable) and previous environmental impacts, where 
appropriate, to inform the baseline levels of both individual health 
and susceptibility to additional stressors, as well as stock status. 
Further, the species-specific assessments in the Analysis and 
Negligible Impact Determination section pull together and address the 
combined injury, behavioral disturbance, and other effects of the 
aggregate MITT activities (and in consideration of applicable 
mitigation) as well as other information that supports our 
determinations that the Navy activities will not adversely affect any 
species via impacts on rates of recruitment or survival. We refer the 
reader to the Analysis and Negligible Impact Determination section for 
this analysis. NMFS has described and applied a reasoned and 
comprehensive approach to evaluating the effects of the Navy activities 
on marine mammal species and their habitat. The Commenter cites various 
articles in which one analytical approach or another was used to 
evaluate particular scenarios or impacts, with no explanation of why 
those methods are more appropriate or applicable.
    Regarding the assertion that NMFS does not adequately consider 
stress responses in its analysis, NMFS does not assume that the impacts 
are insignificant. However, there is currently neither adequate data 
nor a mechanism by which the impacts of stress from acoustic exposure 
can be reliably and independently quantified. Stress effects that 
result from noise exposure likely often occur concurrently with Level B 
harassment (behavioral disturbance) and many are likely captured and 
considered in the quantification of other takes by harassment that 
occur when individuals come within a certain distance of a sound source 
(behavioral disturbance, PTS, and TTS). The effects of these takes were 
fully evaluated in the Analysis and Negligible Impact Determination 
section.
    Comment 54: A Commenter asserted that counter to NMFS' assertion 
that no evidence of population-level consequences exists, an apparent 
beaked whale population sink is observed on the AUTEC range (in the 
Bahamas), attributed to the high levels of cumulative noise exposure at 
the site. They further assert that similar concerns have focused 
attention on resident beaked whale populations on the Navy's SOCAL 
range, which exhibit strenuous responses to mid-frequency sonar 
notwithstanding their repeated exposure.
    Response: It is incorrect to conclude that there is a ``population 
sink'' on the Navy's AUTEC range. In the citation provided (Claridge, 
2013), that statement is merely a hypothesis, yet to be demonstrated. 
When considering the portion of the beaked whale population within the 
SOCAL portion of the HSTT Study Area and as presented in the 2018 HSTT 
final rule and the 2018 HSTT FEIS/OEIS, multiple studies have 
documented continued high abundance of beaked whales and the long-term 
residency of documented individual beaked whales, specifically where 
the Navy has been training and testing for decades (see for example 
Debich et al., 2015a, 2015b; Dimarzio et al., 2018, 2020; Falcone and 
Schorr, 2012, 2014, 2018, 2020; Hildebrand et al., 2009; Moretti, 2016; 
[Scaron]irovi[cacute] et al., 2016; Smultea and Jefferson, 2014). There 
is no evidence that there have been any population-level impacts to 
beaked whales resulting from Navy training and testing in the SOCAL 
portion of the HSTT Study Area. Importantly, no resident beaked whale 
populations have been identified in the MITT Study Area, and both the 
level of activities and the magnitude and severity of associated 
impacts on beaked whales are lower than in the HSTT Study Area.
    Comment 55: A Commenter stated that NMFS has not apparently 
considered the impact of Navy activities on a population basis for many 
of the marine mammal populations within the MITT Study Area. Instead, 
it has lodged discussion for many populations within broader 
categories, most prominently mysticetes and odontocetes, that in some 
cases correspond to general taxonomic groups. Such grouping of stocks 
elides important differences in abundance, demography, distribution, 
and other population-specific factors, making it difficult to assume 
``that the effects of an activity on the different stock populations'' 
are identical. Conservation Council, 97 F.Supp.3d at 1223. That is 
particularly true where small, resident populations are concerned, and 
differences in population abundance, habitat use, and distribution 
relative to Navy activities can be profoundly significant.
    Response: The Commenter erroneously suggests that NMFS makes 
findings specific only to the level of Odontocetes and Mysticetes or 
other general taxonomic groups, which is clearly inaccurate. NMFS first 
provides information regarding broader groups (such as Mysticetes or 
Odontocetes) in order to avoid repeating information that is applicable 
across multiple species (or stocks if applicable), but analyses have 
been conducted and determinations made specific to each species. Thus 
we avoid repeating information applicable to a broader taxonomic group 
or number of species (or stocks where applicable), while also 
presenting and integrating all information needed to support the 
negligible impact determination for a particular species (where no 
stock information is available). We note that in the MITT Study Area, 
species have not been assigned to stocks and there is little or no 
information at the stock level. Please refer to the Analysis and 
Negligible Impact Determination section of this final rule.
    Comment 56: A Commenter asserted that NMFS assumes that all of the 
Navy's estimated impacts would not affect individuals or populations 
through repeated activity--even though the takes anticipated each year 
would affect the same populations and, indeed, would admittedly involve 
extensive use of some of the same biogeographic areas. And, the 
Commenter asserts, while NMFS states that behavioral harassment (aside 
from that caused by masking effects) involves a stress response that 
may contribute to an animal's allostatic load, it assumes without 
further analysis that any such impacts would be insignificant. The 
Commenter further asserts that both statements are factually 
insupportable given the lack of any substantial population analysis or 
quantitative assessment of long-term effects in the proposed rule, in 
addition to the numerous deficiencies in the thresholds and modeling 
that NMFS has adopted from the Navy.
    Response: As previously discussed, Navy activities are spread out 
in the offshore waters around these islands, most activities are unit 
level events which have relatively small footprints of tens of 
kilometers resulting in small percentages of overall habitat affected 
at

[[Page 46339]]

any one time, activities that use sonar or explosives are not conducted 
every day of the year (active sonar use has traditionally been used on 
20 percent of days or less, as reported through the CNA analysis of 
beaked whale strandings), and even within a day sonar use during an 
activity is intermittent (1 ping every 50 seconds) and often for short 
duration periods (minutes to up to a few hours at a time). The impacts 
of stress have been considered in NMFS' assessment (see the Potential 
Effects of Specified Activities on Marine Mammals and Their Habitat 
section of the proposed rule) and are also addressed in the response to 
Comment 53 above. Regarding the take of marine mammals across the 
multiple years of the rule, NMFS has found that in each of the seven 
years of the rule (in which no individuals of any species are expected 
to be taken on more than a few non-sequential days), the authorized 
take is not expected to affect the reproductive success or survivorship 
of any individual marine mammal. Given the lack of any impacts on the 
reproduction or survival of any affected individuals, there will be no 
effects on any species' annual rates of recruitment or survival in any 
year, and therefore no basis to suggest that impacts would accrue over 
the seven years of the rule in a manner that would have a non-
negligible impact on an affected species.
    Comment 57: A Commenter stated that NMFS does not consider the 
potential for acute synergistic effects from multiple activities taking 
place at one time, as happens during major exercises or from Navy 
activities in combination with other actions. For example, the agency 
does not consider the greater susceptibility to vessel strike of 
animals that have been temporarily harassed or disoriented, nor does 
NMFS consider (for example) the synergistic effects of noise with other 
stressors in producing or magnifying a stress response. This lack of 
analysis is not supportable under the MMPA. Without an accurate 
assessment of existing threats to marine mammals, NMFS lacks a 
sufficient environmental baseline to determine whether the Navy's 
action will have more than a negligible impact on marine mammal species 
and stocks.
    Response: NMFS did analyze the potential for aggregate effects from 
mortality, injury, masking, habitat effects, energetic costs, stress, 
hearing loss, and behavioral disturbance from the Navy's activities in 
reaching the negligible impact determinations. The modeling for MTEs 
and all activities includes the accumulated energy of all sonar sources 
and stressors. Outside of MTEs or some or the larger coordinated 
events, it is unlikely for several unit level activities to be 
conducted in the same day in the same location/time to produce 
aggregate effects on an individual. Further, we have explicitly 
discussed the potential interaction of an individual being impacted by 
TTS and behavioral disturbance simultaneously. We refer the reader to 
the Analysis and Negligible Impact Determination section of the final 
rule for the discussion on the potential for aggregate effects of the 
Navy's activities on individuals as well as how these effects on 
individuals relate to potential effects on annual rates of recruitment 
and survival for each species.
    In addition, NMFS fully considers the potential for aggregate/
synergistic effects from all Navy activities. We also consider UMEs 
(when applicable) and previous environmental impacts, where 
appropriate, to inform the baseline levels of both individual health 
and susceptibility to additional stressors, as well as species/stock 
status. Further, the species assessments in the Analysis and Negligible 
Impact Determination section (which have been updated and expanded for 
some species, i.e., humpback whales and beaked whales) pull together 
and address the combined potential mortality, injury, behavioral 
disturbance, and other effects of the aggregate MITT activities (and in 
consideration of applicable mitigation measures) as well as additional 
information from the Potential Effects of Specified Activities on 
Marine Mammals and Their Habitat and Estimated Take of Marine Mammals 
sections to support our determinations that the Navy activities will 
not adversely affect any species via impacts on rates of recruitment or 
survival. We refer the reader to the Analysis and Negligible Impact 
Determination section for this analysis.
    Widespread, extensive monitoring since 2006 on Navy ranges that 
have been used for training and testing for decades has demonstrated no 
evidence of population-level impacts. Based on the best available 
science, including research by NMFS and the Navy's marine mammal 
studies, there is no evidence that ``population-level harm'' to marine 
mammals is occurring in the MITT Study Area. Through the process 
described in the rule and regulations, NMFS will work with the Navy to 
assure that the aggregate or cumulative impacts remain at the 
negligible impact level.
    Regarding the consideration of stress responses, NMFS does not 
assume that the impacts are insignificant. There is currently neither 
adequate data nor a mechanism by which the impacts of stress from 
acoustic exposure can be reliably and independently quantified. 
However, stress effects that result from noise exposure likely often 
occur concurrently with behavioral disturbance and many are likely 
captured and considered in the quantification of other takes by 
harassment that occur when individuals come within a certain distance 
of a sound source (behavioral disturbance, PTS, and TTS). Further, the 
Commenter provides no support for the speculative assertion that 
animals that are harassed would have greater susceptibility to vessel 
strike, but regardless, the agency's analysis of the likelihood of 
vessel strikes considers all available and applicable information (see 
the Potential Effects of Vessel Strike subsection of the Potential 
Effects of Specified Activities on Marine Mammals and Their Habitat 
section of the proposed rule).

NEPA

    Comment 58: A Commenter stated that the Navy (and thereby NMFS, 
since the agency has adopted the 2020 MITT FSEIS/OEIS to satisfy its 
NEPA obligations for the MMPA rulemaking and subsequent issuance of the 
Letter of Authorization) failed its NEPA requirements: (1) To inform 
the public as to its intentions and the potential impacts of those 
intentions in relation to their continued weapons testing in the MITT 
Study Area and (2) To consider all available scientific evidence that 
their activities are resulting in wider take of marine mammals than 
previously known.
    Response: NMFS disagrees that the Navy and NMFS failed to satisfy 
any NEPA requirements. The Navy prepared, with NMFS participating as a 
cooperating agency, and made available for public review and comment 
the 2019 MITT DSEIS/OEIS, which fully analyzed the Navy's and NMFS' 
proposed actions. To better accommodate stakeholders and the public, 
the Navy provided 75 days to review and comment on the 2019 MITT DSEIS/
OEIS. The comment period for the DSEIS/OEIS was from February 1, 2019 
to April 17, 2019, which is 30 days longer than the minimum required 
time for review (40 CFR 6.203(c)(3)(v)).
    The Navy held four open house public meetings, one each on Tinian 
(March 14, 2019), Rota (March 15, 2019), Saipan (March 18, 2019), and 
Guam (March 19, 2019). The public meetings were an ideal opportunity 
for the public to ask questions of Navy team members (and specific 
subject matter experts on Saipan and Guam) about the analysis 
documented in the 2020 MITT FSEIS/OEIS. The Navy encouraged the

[[Page 46340]]

public to attend these meetings and broadly notified the public through 
the media, including paid newspaper advertisements and news releases, 
and direct mail, including letters, postcards, and emails.
    Further, the 2020 MITT FSEIS/OEIS includes the best available 
information regarding the impacts of the Navy's activities on the human 
environment, including marine mammals.
    Comment 59: A Commenter says that NMFS cannot rely on the EIS to 
fulfill its obligations under NEPA. Without significant revision, the 
2019 MITT DSEIS/OEIS cannot meet NMFS' NEPA obligations. The Commenter 
urges NMFS to recognize that the alternatives and mitigation set forth 
in the 2019 MITT DSEIS/OEIS are inadequate and to supplement the 
document accordingly.
    Response: Consistent with the regulations published by the Council 
on Environmental Quality (CEQ), it is common and sound NEPA practice 
for NOAA to participate as a cooperating agency and adopt a lead 
agency's NEPA analysis when, after independent review, NOAA determines 
the document to be sufficient in accordance with 40 CFR 1506.3. 
Specifically here, NOAA is satisfied that the 2020 MITT FEIS/OEIS 
adequately addresses the impacts of issuing the MMPA incidental take 
authorization and that NOAA's comments and concerns have been 
adequately addressed. NMFS' early participation in the NEPA process and 
role in shaping and informing analyses using its special expertise 
ensured that the analysis in the 2020 MITT FSEIS/OEIS is sufficient for 
purposes of NMFS' own NEPA obligations related to its issuance of 
incidental take authorization under the MMPA.
    Regarding the alternatives and mitigation, NMFS' early involvement 
in development of the 2020 MITT FSEIS/OEIS and role in evaluating the 
effects of incidental take under the MMPA ensured that the 2020 MITT 
FSEIS/OEIS would include adequate analysis of a reasonable range of 
alternatives. The 2020 MITT FSEIS/OEIS includes a No Action Alternative 
specifically to address what could happen if NMFS did not issue an MMPA 
authorization. The other two Alternatives address two action options 
that the Navy could potentially pursue while also meeting their 
mandated Title 10 training and testing responsibilities. More 
importantly, these alternatives fully analyze a comprehensive variety 
of mitigation measures. This mitigation analysis supported NMFS' 
evaluation of our mitigation options in potentially issuing an MMPA 
authorization, which, if the authorization can be issued under the 
negligible impact standard, primarily revolves around the appropriate 
mitigation to prescribe. This approach to evaluating a reasonable range 
of alternatives is consistent with NMFS policy and practice for issuing 
MMPA incidental take authorizations. NOAA has independently reviewed 
and evaluated the 2020 MITT FSEIS/OEIS, including the range of 
alternatives, and determined that the 2020 MITT FSEIS/OEIS fully 
satisfies NMFS' NEPA obligations related to its decision to issue the 
MMPA final rule and associated LOA, and we have adopted it.
    Comment 60: To satisfy NEPA's mandate to take a hard look at 
environmental impacts, NMFS and the Navy must incorporate new 
information (Simonis et al., 2020) into their analysis of the impacts 
of MITT activities on marine mammals. Moreover, the agencies must 
evaluate alternatives that prohibit the use of harmful sonar in the 
biologically important areas for beaked whales around Saipan and Tinian 
identified in Simonis et al. (2020).
    Response: NMFS has considered Simonis et al. (2020) in the 
development of this final rule and directs the reader to the Stranding 
section of the rule, as well as the response to Comment 19, in which we 
address the areas around Saipan and Tinian referenced in Simonis et al. 
(2020). Likewise the Navy has considered this new information from 
Simonis et al. (2020) in the 2020 MITT FSEIS/OEIS.

Other Comments

    Comment 61: The Commenter argued that an analysis based on reported 
strikes by Navy vessels alone does not account for the additional risk 
of undetected under-reported whale strikes. In assessing ship-strike 
risk, NMFS and the Navy should include offsets to account for 
potentially undetected and unreported collisions.
    Response: First, it is important to note that NMFS' assessment of 
whether ship strike is likely does not rely wholly on whether or not 
there have been reported strikes by the Navy in the past, but also 
considers the seasonal occurrence and density of large whales, the 
stranding record (which could note strikes by other entities), and the 
relative percentage of Navy vessel traffic. Regarding the likelihood of 
undetected Navy strikes, under Navy-wide policy Navy ships are mandated 
to report any Navy ship strike to marine mammals. To date, there have 
been none in the MITT Study Area from Navy ships. While NMFS agrees 
that broadly speaking the number of total ship strikes from all sources 
may be underestimated due to incomplete information from other sectors 
(shipping, etc.), NMFS is confident that any whales struck by Navy 
vessels are detected and reported (as has occurred in other Navy study 
areas), and therefore relying on the history of Navy vessel strikes is 
appropriate and supported. Navy ships have multiple Lookouts, including 
on the forward part of the ship that can visually detect a struck whale 
(which has occasionally occurred elsewhere), in the unlikely event ship 
personnel do not feel the strike. The Navy's strict internal procedures 
and mitigation requirements in this and previous rules include 
reporting of any vessel strikes of marine mammals, and the Navy's 
discipline, extensive training (not only for detecting marine mammals, 
but for detecting and reporting any potential navigational 
obstruction), and strict chain of command give NMFS a high level of 
confidence that all strikes actually get reported. For more discussion 
of the specific circumstances that make it less likely that Navy 
vessels will strike a marine mammal, see the Potential Effects of 
Specified Activities on Marine Mammals and Their Habitat section in the 
proposed rule. Accordingly, NMFS is confident that the information used 
to support the vessel-strike analysis is accurate and complete, and 
there is no need to include offsets to account for potentially 
undetected and unreported collisions allegedly associated with the 
Navy's training and testing activities.
    Separately, there is no evidence that Navy training and testing 
activities (including acoustic activities) increase the risk of nearby 
non-Navy vessels (or other nearby Navy vessels not involved in the 
training or testing activities) striking marine mammals.

Changes From the Proposed Rule to the Final Rule

    Between the proposed rule and the final rule, mitigation, 
monitoring, reporting, and adaptive management measures have been 
added, augmented, and clarified, and the negligible impact analysis for 
humpback whales around Saipan has been modified.
    Specifically regarding the humpback whale assessment, since 
publication of the proposed rule, additional information and analysis 
have been used to refine the assessment for the impacts of sonar 
training and testing on humpback whales around Saipan, resulting in an 
increase in the total take numbers for humpback whales. A subsection 
describing this additional analysis and how it changes the take numbers 
(Humpback Whales Around

[[Page 46341]]

Saipan) has been added to the Estimated Take of Marine Mammals section 
and the total take numbers for humpback whales have been changed in 
Table 28 and Table 47.
    Regarding the changes to mitigation measures, in the Marpi Reef and 
Chalan Kanoa Reef Geographic Mitigation Areas, where there was 
previously a limitation on the use of explosives but no limitation on 
the use of active sonar, there is now a 20-hr annual cap between 
December 1 and April 30 on the use of hull-mounted MF1 mid-frequency 
active sonar for these areas (20 hrs total for both areas combined), as 
well as a requirement that the Navy report all active sonar use (all 
bins, by bin) in these areas between December 1 and April 30. These 
changes are discussed in greater detail in the Mitigation Measures 
section of this rule.
    In addition, the Navy has committed to the following actions, which 
will expand the science and inform future adaptive management actions 
related to beaked whales, specifically, as well as other species in the 
MITT Study Area:
    1. Co-funding the Pacific Marine Assessment Program for Protected 
Species (PACMAPPS) survey in spring-summer 2021 to help document beaked 
whale occurrence, abundance, and distribution in the Mariana Islands. 
This effort will include deployments of a towed array as well as 
floating passive acoustic buoys.
    2. Continuing to fund additional stranding response/necropsy 
analyses for the Pacific Islands region.
    3. Submitting a proposal through the annual Federally Funded 
Research and Development Center (FFRDC) call to fund Center for Naval 
Analysis (CNA) to develop a framework to improve the analysis of single 
and mass stranding events, including the development of more advanced 
statistical methods to better characterize the uncertainty associated 
with data parameters.
    4. Increasing analysis for any future beaked whale stranding in the 
Mariana Islands to include detailed Navy review of available records of 
sonar use.
    5. Monitoring future beaked whale occurrence within select portions 
of the MITT Study Area starting in 2022 (so as to not duplicate efforts 
from item number 1 above).
    6. Including Cuvier's beaked whales as a priority species for 
analysis under a 2020-2023 Navy research-funded program entitled Marine 
Species Monitoring for Potential Consequences of Disturbance 
(MSM4PCOD).
    7. Funding and co-organizing with NMFS an expert panel to provide 
recommendations on scientific data gaps and uncertainties for further 
protective measure consideration to minimize the impact of Navy 
training and testing activities on beaked whales in the Mariana 
Islands.
    These changes are discussed in greater detail in the Monitoring and 
Adaptive Management sections of this rule.

Description of Marine Mammals and Their Habitat in the Area of the 
Specified Activities

    Marine mammal species that have the potential to occur in the MITT 
Study Area are presented in Table 7. The Navy anticipates the take of 
individuals of 26 marine mammal species by Level A and Level B 
harassment incidental to training and testing activities from the use 
of sonar and other transducers, and in-water detonations. There are no 
areas of critical habitat designated under the Endangered Species Act 
(ESA), National Marine Sanctuaries, or unusual mortality events (UMEs) 
for marine mammals in the MITT Study Area. However, there are areas 
known to be important for humpback whale breeding and calving which are 
described below.
    The proposed rule included additional information about the species 
in this rule, all of which remains valid and applicable but has not 
been reprinted in this final rule, including a subsection entitled 
Marine Mammal Hearing that described the importance of sound to marine 
mammals and characterized the different groups of marine mammals based 
on their hearing sensitivity. Therefore, we refer the reader to our 
Federal Register notice of proposed rulemaking (85 FR 5782; January 31, 
2020) for more information.
    Information on the status, distribution, abundance, population 
trends, habitat, and ecology of marine mammals in the MITT Study Area 
also may be found in Section 4 of the Navy's rulemaking/LOA 
application. NMFS reviewed this information and found it to be accurate 
and complete. Additional information on the general biology and ecology 
of marine mammals is included in the 2020 MITT FSEIS/OEIS. The marine 
mammal populations in the MITT Study Area have not been assigned to 
stocks and there are no associated SARs. There is only one species, 
humpback whales for which stock information exists for species that 
occur in the MITT Study Area. Table 7 incorporates the best available 
science, including data from the U.S. Pacific and the Alaska Marine 
Mammal Stock Assessments Reports (SARs) (Carretta et al., 2019, Muto et 
al., 2019), as well as monitoring data from the Navy's marine mammal 
research efforts. NMFS also has reviewed the most recent 2019 draft 
SARs (which can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports) 
and new scientific literature, and determined that none of these nor 
any other new information changes our determination of which species 
have the potential to be affected by the Navy's activities or the 
pertinent information in this final rulemaking.

                                              Table 7--Marine Mammal Occurrence Within the MITT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Status                                       Occurrence *
            Common name                Scientific name    ----------------------------------------------------------------------------------------------
                                                                    MMPA                     ESA               Mariana Islands        Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Mysticetes:
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale........................  Balaenoptera musculus  D.....................  E.....................  Seasonal..............  Seasonal.
Bryde's whale.....................  Balaenoptera edeni...  ......................  n/a...................  Regular...............  Regular.
Fin whale.........................  Balaenoptera physalus  D.....................  E.....................  Rare..................  Rare.
Humpback whale....................  Megaptera              (\1\).................  E.....................  Seasonal..............  Seasonal.
                                     novaeangliae.
Minke whale.......................  Balaenoptera           ......................  n/a...................  Seasonal..............  Seasonal.
                                     acutorostrata.
Omura's whale.....................  Balaenoptera omurai..  ......................  n/a...................  Rare..................  Rare.
Sei whale.........................  Balaenoptera borealis  D.....................  E.....................  Seasonal..............  Seasonal.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Odontocetes:
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blainville's beaked whale.........  Mesoplodon             ......................  n/a...................  Regular...............  Regular.
                                     densirostris.

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Common bottlenose dolphin.........  Tursiops truncatus...  ......................  n/a...................  Regular...............  Regular.
Cuvier's beaked whale.............  Ziphius cavirostris..  ......................  n/a...................  Regular...............  Regular.
Dwarf sperm whale.................  Kogia sima...........  ......................  n/a...................  Regular...............  Regular.
False killer whale................  Pseudorca crassidens.  ......................  n/a...................  Regular...............  Regular.
Fraser's dolphin..................  Lagenodelphis hosei..  ......................  n/a...................  Regular...............  Regular.
Ginkgo-toothed beaked whale.......  Mesoplodon ginkgodens  ......................  n/a...................  Regular...............  Regular.
Killer whale......................  Orcinus orca.........  ......................  n/a...................  Regular...............  Regular.
Longman's beaked whale............  Indopacetus pacificus  ......................  n/a...................  Regular...............  Regular.
Melon-headed whale................  Peponocephala electra  ......................  n/a...................  Regular...............  Regular.
Pantropical spotted dolphin.......  Stenella attenuata...  ......................  n/a...................  Regular...............  Regular.
Pygmy killer whale................  Feresa attenuata.....  ......................  n/a...................  Regular...............  Regular.
Pygmy sperm whale.................  Kogia breviceps......  ......................  n/a...................  Regular...............  Regular.
Risso's dolphin...................  Grampus griseus......  ......................  n/a...................  Regular...............  Regular.
Rough-toothed dolphin.............  Steno bredanensis....  ......................  n/a...................  Regular...............  Regular.
Short-finned pilot whale..........  Globicephala           ......................  n/a...................  Regular...............  Regular.
                                     macrorhynchus.
Sperm whale.......................  Physeter               D.....................  E.....................  Regular...............  Regular.
                                     macrocephalus.
Spinner dolphin...................  Stenella longirostris  ......................  n/a...................  Regular...............  Regular.
Striped dolphin...................  Stenella coeruleoalba  ......................  n/a...................  Regular...............  Regular.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Humpback whales in the Mariana Islands have not been assigned a stock by NMFS in the Alaska or Pacific Stock Assessment Reports given they are not
  recognized in those reports as being present in U.S. territorial waters (Carretta et al., 2017c; Carretta et al., 2018; Caretta et al., 2019; Muto et
  al., 2017b; Muto et al., 2018, Muto et al., 2019), but because individuals from the Western North Pacific Distinct Population Segment have been
  photographically identified in the MITT Study Area, humpback whales in the Mariana Islands are assumed to be part of the Western North Pacific Stock.
Note: Status MMPA, D = depleted; ESA, E = endangered.
* Species occur in both the Mariana Islands and in the Transit Corridor, both of which are included in the overall MITT Study Area. The transit corridor
  is outside the geographic boundaries of the MIRC, but is a route across the high seas for Navy ships transiting between the MIRC and the HRC. Although
  not part of a defined range complex, vessels and aircraft would at times conduct basic and routine unit-level activities such as gunnery and sonar
  training while in transit in the corridor as long as the training would not interfere with the primary objective of reaching their intended
  destination. Ships also conduct sonar maintenance, which includes active sonar transmissions.

Humpback Reproductive Areas

    The humpback whales in the MITT Study Area are indirectly addressed 
in the Alaska SAR, given that the historic range of humpbacks in the 
``Asia wintering area'' includes the Mariana Islands. The observed 
presence of humpback whales in the Mariana Islands (Hill et al., 2016a; 
Hill et al., 2017a; Hill et al., 2018; Hill et al., 2020a; Klinck et 
al., 2016a; Munger et al., 2014; NMFS, 2018; Oleson et al., 2015; 
Uyeyama, 2014) is consistent with the MITT Study Area as a plausible 
migratory destination for humpback whales from Alaska (Muto et al., 
2017a). It was considered likely that humpback whales in the Mariana 
Islands are part of the endangered Western North Pacific (WNP) Distinct 
Population Segment (DPS) based on the best available science (Bettridge 
et al., 2015; Calambokidis et al., 2008; Calambokidis et al., 2010; 
Carretta et al., 2017b; Hill et al., 2017b; Hill et al., 2020a; Muto et 
al., 2017a; NMFS, 2016a; NOAA, 2015b; Wade et al., 2016) although the 
breeding range of the humpback whale WNP DPS is not fully resolved. 
Individual photo-identification data for whales sampled off Saipan 
within the Mariana Archipelago in February-March 2015 to 2018, suggest 
that these whales belong to the WNP DPS (Hill et al., 2020a). 
Specifically, comparisons with existing WNP humpback whale photo-
identification catalogs showed that 11 of 41 (27 percent) whales within 
the Mariana Archipelago humpback whale catalog were previously sighted 
in Western North Pacific humpback whale breeding areas (Japan and 
Philippines) and/or in a Western North Pacific humpback whale feeding 
area off Russia (Hill et al., 2020a). Hill et al. (2020a) completed DNA 
profiling of 28 biopsy samples that identified 24 individuals (14 
females, 10 males) representing seven mitochondrial DNA haplotypes. The 
haplotype frequencies from the Mariana Archipelago showed the greatest 
identity with the Ogasawara breeding ground and Commander Islands 
feeding ground in the Western North Pacific. This study establishes the 
Mariana Archipelago as a breeding area for the endangered WNP DPS of 
humpback whales (Hill et al., 2020a). No ESA critical habitat has been 
proposed for the WNP DPS of humpback whales in the MITT Study Area, 
although critical habitat has been proposed in Alaska (84 FR 54534; 
October 9, 2019).
    Humpback whale breeding and calving have been documented in the 
MITT Study Area and particularly in the shallow waters (mostly within 
the 200-m isobath) offshore of Saipan at Marpi Reef and Chalan Kanoa 
Reef. Based on surveys conducted by NMFS' Pacific Islands Fisheries 
Science Center (PIFSC) during the winter months (January to March) 
2015-2019, there were 22 encounters with mother/calf pairs with a total 
of 14 mother/calf pairs and all calves were considered born within the 
current season and one neotate (Hill et al., 2020a). Additionally, 
competitive groups were observed in 2017 and 2018 (Hill et al., 2020a). 
Surveys and passive acoustic hydrophone recordings in the Mariana 
Islands has confirmed the presence of mother-calf pairs, non-calf 
whales, and singing males in the MITT Study Area (Fulling et al., 2011; 
Hill et al., 2016a; Hill et al., 2018; Munger et al., 2014; Munger et 
al., 2015; Norris et al., 2012; Oleson and Hill, 2010a; Oleson et al., 
2015; U.S. Department of the Navy, 2007; Uyeyama et al., 2012). Future 
surveys are needed to determine the full extent of the humpback whale 
breeding habitat throughout the Mariana Archipelago; however, the 
available data confirms the shallow waters surrounding Marpi Reef and 
Chalan Kanoa Reef are important to breeding and calving humpback 
whales.

Species Not Included in the Analysis

    Consistent with the analysis provided in the 2015 MITT FEIS/OEIS 
and the

[[Page 46343]]

previous Phase II rulemaking for the MITT Study Area, the species 
carried forward for analysis and in the Navy's rulemaking/LOA 
application are those likely to be found in the MITT Study Area based 
on the most recent sighting, survey, and habitat modeling data 
available. The analysis does not include species that may have once 
inhabited or transited the area, but have not been sighted in recent 
years (e.g., species that no longer occur in the area due to factors 
such as 19th-century commercial exploitation). These species include 
the North Pacific right whale (Eubalaena japonica), the western 
subpopulation of gray whale (Eschrichtius robustus), short-beaked 
common dolphin (Delphinus delphis), Indo-Pacific bottlenose dolphin 
(Tursiops aduncus), northern elephant seal (Mirounga angustirostris), 
and dugong (Dugong dugon). The reasons for not including each of these 
species was explained in detail in the proposed rulemaking (85 FR 5782; 
January 31, 2020) and NMFS agrees these species are unlikely to occur 
in the MITT Study Area.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    We provided a detailed discussion of the potential effects of the 
specified activity on marine mammals and their habitat in our Federal 
Register notice of proposed rulemaking (85 FR 5782; January 31, 2020). 
In the Potential Effects of Specified Activities on Marine Mammals and 
Their Habitat section of the proposed rule, NMFS provided a description 
of the ways marine mammals may be affected by these activities in the 
form of, among other things, serious injury or mortality, physical 
trauma, sensory impairment (permanent and temporary threshold shift and 
acoustic masking), physiological responses (particularly stress 
responses), behavioral disturbance, or habitat effects. All of this 
information remains valid and applicable. Therefore, we do not reprint 
the information here but refer the reader to that document.
    NMFS has also reviewed new relevant information from the scientific 
literature since publication of the proposed rule. Summaries of the new 
key scientific literature since publication of the proposed rule are 
presented below.
    Accomando et al. (2020) examined the directional dependence of 
hearing thresholds for 2, 10, 20, and 30 kHz in two adult bottlenose 
dolphins. They observed that source direction (i.e., the relative angle 
between the sound source location and the dolphin) impacted hearing 
thresholds for these frequencies. Sounds projected from directly behind 
the dolphins resulted in frequency-dependent increases in hearing 
thresholds of up to 18.5 dB when compared to sounds projected from in 
front of the dolphins. Sounds projected directly above the dolphins 
resulted in thresholds that were approximately 8 dB higher than those 
obtained when sounds were projected below the dolphins. These findings 
suggest that dolphins may receive lower source levels when they are 
oriented 180 degrees away from the sound source, and dolphins are less 
sensitive to sound projected from above (leading to some spatial 
release from masking). Directional or spatial hearing also allows 
animals to locate sound sources. This study indicates dolphins can 
detect source direction at lower frequencies than previously thought, 
allowing them to successfully avoid or approach biologically 
significant or anthropogenic sound sources at these frequencies.
    Houser et al. (2020) measured cortisol, aldosterone, and 
epinephrine levels in the blood samples of 30 bottlenose dolphins 
before and after exposure to simulated U.S. Navy mid-frequency sonar 
from 115-185 dB re: 1 [mu]Pa. They collected blood samples 
approximately one week prior to, immediately following, and 
approximately one week after exposures and analyzed for hormones via 
radioimmunoassay. Aldosterone levels were below the detection limits in 
all samples. While the observed severity of behavioral responses scaled 
(increased) with SPL, levels of cortisol and epinephrine did not show 
consistent relationships with received SPL. The authors note that it is 
still unclear whether intermittent, high-level acoustic stimuli elicit 
endocrine responses consistent with a stress response, and that 
additional research is needed to determine the relationship between 
behavioral responses and physiological responses.
    In an effort to compare behavioral responses to continuous active 
sonar (CAS) and pulsed (intermittent) active sonar (PAS), Isojunno et 
al. (2020) conducted at-sea experiments on 16 sperm whales equipped 
with animal-attached sound- and movement-recording tags in Norway. They 
examined changes in foraging effort and proxies for foraging success 
and cost during sonar and control exposures after accounting for 
baseline variation. They observed no reduction in time spent foraging 
during exposures to medium-level PAS transmitted at the same peak 
amplitude as CAS, however they observed similar reductions in foraging 
during CAS and PAS when they were received at similar energy levels 
(SELs). The authors note that these results support the hypothesis that 
sound energy (SEL) is the main cause of behavioral responses rather 
than sound amplitude (SPL), and that exposure context and measurements 
of cumulative sound energy are important considerations for future 
research and noise impact assessments.
    Frankel and Stein (2020) used shoreline theodolite tracking to 
examine potential behavioral responses of southbound migrating eastern 
gray whales to a high-frequency active sonar system transmitted by a 
vessel located off the coast of California. The sonar transducer 
deployed from the vessel transmitted 21-25 kHz sweeps for half of each 
day (experimental period), and no sound the other half of the day 
(control period). In contrast to low-frequency active sonar tests 
conducted in the same area (Clark et al., 1999; Tyack and Clark, 1998), 
no overt behavioral responses or deflections were observed in field or 
visual data. However, statistical analysis of the tracking data 
indicated that during experimental periods at received levels of 
approximately 148 dB re: 1 [mu]Pa\2\ (134 dB re: 1 [mu]Pa\2\s) and less 
than 2 km from the transmitting vessel, gray whales deflected their 
migration paths inshore from the vessel. The authors indicate that 
these data suggest the functional hearing sensitivity of gray whales 
extends to at least 21 kHz. These findings agree with the predicted 
mysticete hearing curve and behavioral response functions used in the 
analysis to estimate take by Level A harassment (PTS) and Level B 
harassment (behavioral response) for this rule (see the Technical 
Report ``Criteria and Thresholds for U.S. Navy Acoustic and Explosive 
Effects Analysis (Phase III)'').
    Having considered the new information, along with information 
provided in public comments on the proposed rule, we have determined 
that there is no new information that substantively affects our 
analysis of potential impacts on marine mammals and their habitat that 
appeared in the proposed rule, all of which remains applicable and 
valid for our assessment of the effects of the Navy's activities during 
the seven-year period of this rule.

Vessel Strike

    NMFS also considered the chance that a vessel utilized in training 
or testing activities could strike a marine mammal. Vessel strikes have 
the potential to result in incidental take from serious injury and/or 
mortality. Vessel strikes are not specific to any particular training 
or testing activity,

[[Page 46344]]

but rather are a limited, sporadic, and incidental result of Navy 
vessel movement within a study area. NMFS' detailed analysis of the 
likelihood of vessel strike was provided in the Potential Effects of 
Vessel Strike section of our Federal Register notice of proposed 
rulemaking (85 FR 5782; January 31, 2020); please see that notice of 
proposed rulemaking or the Navy's application for more information. No 
additional information has been received since publication of the 
proposed rule that substantively changes the agency's analysis or 
conclusions. Therefore the information and analysis included in the 
proposed rule supports NMFS' concurrence with the Navy's conclusion and 
our final determination that vessel strikes of marine mammals, and 
associated serious injury or mortality, are not likely to result from 
the Navy's activities included in this seven-year rule, and vessel 
strikes are not discussed further.

Stranding

    In the proposed rule, NMFS discussed the potential mechanisms that 
could lead from acoustic exposure to marine mammal strandings and 
described the small number of global events in which strandings 
(predominantly of beaked whales) have been causally associated with 
exposure to active sonar in certain circumstances. Given the available 
information, NMFS did not anticipate or propose to authorize mortality 
of beaked whales resulting from the Navy activities covered under the 
rule. Public commenters questioned this preliminary determination and 
additional information has become available since the proposed rule was 
published. Therefore an updated and expanded rationale, in addition to 
what was included in the proposed rule, describing why NMFS continues 
to conclude that mortality is not reasonably likely to result from 
these activities following careful and thorough review of all available 
information is included here.
    In February 2020, a study (Simonis et al., 2020) was published 
titled ``Co-occurrence of beaked whale strandings and naval sonar in 
the Mariana Islands, Western Pacific.'' In summary, the authors 
compiled the publicly available information regarding Navy training 
exercises from 2006-2019 (from press releases, etc.), as well as the 
passive acoustic monitoring data indicating sonar use that they 
collected at two specific locations on HARP recorders over a shorter 
amount of time, and compared it to the dates of beaked whale 
strandings. Using this data, they reported that six of the 10 Cuvier's 
beaked whales, from four of eight events, stranded during or within six 
days of a naval ASW exercise using sonar. In a Note to the article, the 
authors acknowledged additional information provided by the Navy while 
the article was in press that one of the strandings occurred a day 
prior to sonar transmissions and so should not be considered coincident 
with sonar. The authors' analysis examined the probability that the now 
three of eight random days would fall during, or within six days after, 
a naval event (utilizing the Navy training events and sonar detections 
of which the authors were aware). Their test results indicated that the 
probability that three of eight stranding events were randomly 
associated with naval sonar was one percent.
    The authors did not have access to the Navy's classified data (in 
the Note added to the article, Simonis et al. noted that the Navy was 
working with NMFS to make the broader classified dataset available for 
further statistical analysis). Later reporting by the Navy indicated 
there were more than three times as many sonar days in the Marianas 
during the designated time period than Simonis et al. (2020) reported. 
Primarily for this reason, the Navy tasked the Center for Naval 
Analysis (CNA) with repeating the statistical examination of Simonis et 
al. using the full classified sonar record, including ship movement 
information to document the precise times and locations of Navy sonar 
use throughout the time period of consideration (2007-2019).
    CNA re-evaluated the relationship between the strandings and sonar 
activities using the entire classified data set in two ways. First, 
from their sonar database, CNA tabulated the number of ``sonar days'' 
for use in their analysis. The total number of sonar days from the 
classified database was 923 days (or approximately 19.5 percent of all 
days in the study timeframe). In comparison, the Simonis et al. (2020) 
analysis assumed only 293 days of sonar (or approximately 6.1 percent 
of all days in the study timeframe). CNA conducted re-constructions for 
each stranding event to determine/confirm if Navy sonar use coincided 
in time and space with each stranding location. The Navy extended the 
analysis through the entire year of 2019 to capture both sonar use and 
stranding events. As a result, the CNA analysis included consideration 
of the November 2019 stranding of a single beaked whale on Rota, which 
was not addressed in the Simonis et al. (2020) paper.
    A distance of 80 nmi is used in NMFS' incidental take regulations 
to evaluate strandings in the context of major training events (MTE), 
although of note none of the Marianas stranding events occurred during 
an MTE. All strandings reported to have been coincident with sonar use 
in Simonis et al., as well as the additional stranding that occurred 
while Simonis et al. was in press, were confirmed to be coincident by 
the CNA analysis (i.e., within 80 nmi) and, for the first analysis, CNA 
examined the four strandings in relation to the total sonar days 
(throughout the MITT Study Area) recorded in the classified data set. 
Based on the calculations conducted by CNA, when the analysis is 
conducted consistent with the Simonis et al. (2020) assumptions (i.e., 
without considering proximity of sonar to strandings in counting 
``sonar days''), but with consideration of the accurate number of sonar 
days from the classified record and the additional stranding at Rota, 
the analysis suggests that the probability that four of nine stranding 
events were randomly associated with naval events is 10 percent, which 
the Navy interpreted as insufficient evidence, at P<0.10 threshold 
level, to claim a relationship between sonar use and stranding in the 
Mariana Islands.
    For the second CNA analysis, the same four coincident strandings 
were considered, but only sonar use within a maximum distance of 80 nmi 
from a stranding location would be considered as possibly influencing a 
potential stranding event and, therefore, included in the ``sonar 
days'' for this analysis. This analysis resulted in the calculations 
being performed separately for Guam, Rota, and Saipan.
    When the analysis was conducted specifically for Guam including 
only those sonar days within 80 nmi, the results suggested that the 
probability that the strandings are randomly associated with sonar was 
notably higher, at 26 percent (p=0.26). This is notable because this 
location had the highest number of overall stranding events (n=7), 
coincident stranding events (n=2), and sonar days (n=681) of all the 
locations within the Mariana Islands. The calculations for Saipan and 
Rota (p=0.06 and 0.14, respectively) should be viewed with caution 
given that statistical analyses considering single data points (i.e., 
one stranding each) have low power and high uncertainty and, similarly, 
the Navy reported insufficient evidence to claim a relationship (at 
P<0. 05 and 0.10 levels, respectively) between sonar use and 
strandings. NMFS has evaluated the Navy's analysis and results along 
with the analysis and results of Simonis et al. (2020), and has 
determined that both

[[Page 46345]]

analyses are appropriate to consider in NMFS' assessment of whether 
beaked whale mortality is reasonably likely to occur as a result of the 
Navy's activities described in this seven-year rule.
    Standard statistical significance thresholds of 0.05 and 0.1 are 
often used in the interpretation of the results of statistical tests, 
and the Navy stated that their results show that the data showing the 
relationship between sonar and stranding is not statistically 
significant, and does not allow one to rule out a null hypothesis that 
there is no relationship. NMFS consulted guidance from the American 
Statistical Association, which cautions against strict interpretations 
of p-values and notes that ``researchers should bring many contextual 
factors into play to derive scientific inferences, including the design 
of a study, the quality of the measurements, the external evidence for 
the phenomenon under study, and the validity of assumptions that 
underlie the data analysis. Pragmatic considerations often require 
binary, ``yes-no'' decisions, but this does not mean that p-values 
alone can ensure that a decision is correct or incorrect.'' Separately, 
we also note that the Navy strove to use identical methods as the 
Simonis et al. (2020) paper to conduct their analysis. A 
miscommunication resulted in the Navy initially using a Poisson 
distribution, while Simonis et al. used a permutation test, however, 
additional tests were run to ensure an apples-to-apples comparison. The 
tests were consistent and the results are reflected in the discussion 
above. Last, and importantly, we note that correlation does not equate 
to causation.
    In addition to examining the correlation (or lack thereof) of 
activities with strandings, necropsies of stranded animals can provide 
insight into the potential cause of death. The number of strandings 
that can be thoroughly investigated through necropsy, sample 
collection, and advanced diagnostics is limited to animals that are not 
returned to the sea and those that are found and accessible prior to 
extensive decomposition. In the case of beaked whale strandings that 
occurred in the MITT Study Area during this time period, necropsy 
examinations were performed and high quality tissue samples were 
collected from three live stranded or fresh dead individuals: one of 
the whales from the August 2011 Saipan stranding, the single whale from 
the March 2015 Guam stranding, and the single whale from the January 
2019 Guam stranding. For the stranding events for which necropsies and 
histopathology analyses were conducted, only the 2011 and 2015 events 
were coincident with the use of Navy sonar.
    None of the three beaked whales from the Mariana Islands had 
evidence of gas bubble formation in the organs examined grossly and 
histologically. Stranding response staff from the University of Hawaii 
conducted the examinations and compared the results to the diagnostic 
features of gas and fat embolic syndrome described by Bernaldo de 
Quiros et al. (2019). Bernaldo de Quiros et al. (2019) established that 
to date, strandings which have a confirmed association with naval 
exercise have exhibited all seven of the following diagnostic features:
    1. Individual or multiple animals stranded within hours or a few 
days of an exercise in good body condition;
    2. Food remnants in the first gastric compartment ranging from 
undigested food to squid beaks;
    3. Abundant gas bubbles widely distributed in veins (subcutaneous, 
mesenteric, portal, coronary, subarachnoid veins, etc.) composed 
primarily of N2 in fresh carcasses;
    4. Gross subarachnoid and/or acoustic fat hemorrhages;
    5. Microscopic multi-organ gas and fat emboli associated with 
bronchopulmonary shock;
    6. Diffuse, mild to moderate, acute, monophasic myonecrosis 
(hyaline degeneration) with ``disintegration'' of the interstitial 
connective tissue and related structures, including fat deposits, and 
their replacement by amorphous hyaline material (degraded material) in 
fresh and well preserved carcasses; and
    7. Multi-organ microscopic hemorrhages of varying severity in 
lipid-rich tissues such as the central nervous system, spinal cord, and 
the coronary and kidney fat when present.
    Results from the necropsies for the 2011 and 2015 stranded animals 
indicate that they only exhibited one to three of the diagnostic 
features, but not all seven. Additionally, the necropsy results from 
both animals indicated severe parasite infestations. The 2015 specimen 
also had indication of myocardial fibrosis which could have impacted 
cardiac function. Results for the 2019 animal, which was a stranding 
that was not coincident with sonar, indicated that it exhibited up to 
3\1\ of the 7 diagnostic features. Overall, the results of these 
necropsies appear to align with evidence from single beaked whale 
strandings in the Canary Islands between 2002 and 2015 (n=45) which 
stranded with no known correlation in space or time with active sonar. 
These individuals had one or more diagnostic features of gas and fat 
embolic syndrome for beaked whales stranded in association with MFAS 
exercises, but not all seven (Bernaldo de Quiros et al. 2019). NMFS 
acknowledges that situations could potentially occur in which beaked 
whales might strand as a result of sonar exposure and not exhibit all 
seven of the features of gas and fat embolic syndrome described above, 
however, taken as a whole, these necropsy and histopathology results do 
not support a conclusion that the 2011 and 2015 strandings resulted 
from exposure to naval sonar. Furthermore, the role of natural 
stressors or other non-Navy factors as they affect beaked whale 
strandings is not understood. The majority of strandings in the MITT 
Study Area occurred without the presence of Navy sonar.
---------------------------------------------------------------------------

    \1\ One of the diagnostic features is ``individual or multiple 
animals stranded within hours or a few days of an exercise in good 
body condition,'' however, Bernaldo de Quiros et al. (2019) does not 
specify if the stranding had to occur after an exercise in which 
sonar use occurred. One would presume it does since it investigated 
sonar's ability to cause strandings. The 2019 animal stranded close 
in time to the outset of a Navy training event, however, sonar use 
did not occur until the day after the stranding. Therefore, this 
event is not considered coincident, but due to the ambiguity in the 
description of this diagnostic factor, the 2019 stranding is 
conservatively assumed to be positive for this factor.
---------------------------------------------------------------------------

    As noted previously, NMFS has acknowledged that it is possible for 
naval activities using hull-mounted tactical sonar to contribute to the 
death of marine mammals in certain circumstances via strandings 
resulting from behaviorally mediated physiological impacts or other 
gas-related injuries. In the proposed rule, NMFS discussed these 
potential causes and outlined the few cases where active naval sonar 
(in the United States or, largely, elsewhere) had either potentially 
contributed to or (as with the Bahamas example) been more definitively 
causally linked with marine mammal mass strandings (more than two 
animals). There have been no documented mass strandings of beaked 
whales in the Marianas since stranding data was collected, and the 
first beaked whale stranding was documented in 2007, while the Navy has 
been using sonar in the Marianas since the 1960s. As also noted 
previously, there are a suite of factors that have been associated with 
the specific cases of strandings directly causally associated with 
sonar (steep bathymetry, multiple hull-mounted platforms using sonar 
simultaneously, constricted channels, strong surface ducts, etc.) that 
are not present together in the MITT Study Area

[[Page 46346]]

and during the specified activities (and which the Navy takes care 
across the world not to operate under without additional monitoring). 
Further none of the documented strandings in the MITT Study Area have 
coincided with MTEs.
    While the results of the Simonis et al. (2020) paper and the fuller 
CNA analysis both suggest (the latter to a notably lesser degree) that 
it is more probable than not that there was some form of non-random 
relationship between sonar days and strandings in the Marianas during 
this period of time, the results of the Navy analysis (using the full 
dataset) allow, statistically, that the strandings and sonar use may 
not be related. Given the uncertainties and assumptions inherent in 
these correlation analyses, the small sample size (in terms of the 
strandings), and the fact that correlation does not equate to 
causation--these results, alone, do not indicate a reasonable 
likelihood that the Navy's activities under this rule will result in 
serious injury or mortality of beaked whales. Further, the necropsies 
of the two animals stranded in the MITT Study Area in 2011 and 2015 do 
not support a conclusion that the 2011 and 2015 strandings resulted 
from exposure to naval sonar. When this information is considered in 
combination with the absence of mass beaked whale strandings in the 
MITT Study Area and the absence of beaked whale strandings coinciding 
with any MTEs, despite Navy sonar training activity in the area since 
the 1960s, NMFS has concluded that serious injury or mortality of 
beaked whales is unlikely to result from the Navy activities covered 
under this seven-year rule.
    While we have found that serious injury or mortality are not likely 
to result from the activities covered by this rule, we note the number 
of beaked whale strandings in the MITT Study Area (acknowledging the 
comparatively lower carcass recovery rate for offshore species), the 
paucity of beaked whale data in the region, and the Simonis et al. and 
Navy analysis results, all of which highlight the need for additional 
data-gathering and future analysis. Accordingly, as part of the 
monitoring and adaptive management requirements of the final rule (as 
described elsewhere), in addition to continuing to fund stranding 
investigations in the Marianas and other monitoring measures, the Navy 
will fund and co-organize with NMFS an expert panel to provide 
recommendations addressing scientific data gaps and uncertainties to 
further inform consideration of future protective measures to minimize 
the impact of Navy training and testing activities on beaked whales in 
the Mariana Islands.

Estimated Take of Marine Mammals

    This section indicates the number of takes that NMFS is 
authorizing, which are based on the maximum amount of take that NMFS 
anticipates is likely to occur. NMFS coordinated closely with the Navy 
in the development of their incidental take application, and agrees 
that the methods the Navy put forth to estimate take (including the 
model, thresholds, and density estimates), and the resulting numbers 
are based on the best available science and appropriate for 
authorization. Nonetheless, since publication of the proposed rule, 
additional information and analysis have been used to refine the 
assessment for the impacts of sonar training and testing on humpback 
whales around Saipan, resulting in a change in the total take numbers 
for humpback whales. A subsection describing this additional analysis 
and how it changes the take numbers (Humpback Whales Around Saipan) is 
included below and the total take numbers for humpback whales has 
increased in Table 28 and 47.
    Takes are in the form of harassment only. For military readiness 
activities, the MMPA defines ``harassment'' as (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).
    Authorized takes will primarily be in the form of Level B 
harassment, as use of the acoustic and explosive sources (i.e., sonar 
and explosives) is more likely to result in behavioral disruption 
(rising to the level of a take as described above) or temporary 
threshold shift (TTS) for marine mammals than other forms of take. 
There is also the potential for Level A harassment, however, in the 
form of auditory injury and/or tissue damage (the latter from 
explosives only) to result from exposure to the sound sources utilized 
in training and testing activities.
    Generally speaking, for acoustic impacts NMFS estimates the amount 
and type of harassment by considering: (1) Acoustic thresholds above 
which NMFS believes the best available science indicates marine mammals 
will be taken by Level B harassment (in this case, as defined in the 
military readiness definition of Level B harassment included above) or 
incur some degree of temporary or permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day or event; (3) the density or occurrence of marine mammals within 
these ensonified areas; and (4) the number of days of activities or 
events. Below, we describe these components in more detail and present 
the take estimates.

Acoustic Thresholds

    Using the best available science, NMFS, in coordination with the 
Navy, has established acoustic thresholds that identify the most 
appropriate received level of underwater sound above which marine 
mammals exposed to these sound sources could be reasonably expected to 
experience a disruption in behavior patterns to a point where they are 
abandoned or significantly altered, or to incur TTS (equated to Level B 
harassment) or PTS of some degree (equated to Level A harassment). 
Thresholds have also been developed to identify the pressure levels 
above which animals may incur non-auditory injury from exposure to 
pressure waves from explosive detonation.
    Despite the quickly evolving science, there are still challenges in 
quantifying expected behavioral responses that qualify as take by Level 
B harassment, especially where the goal is to use one or two 
predictable indicators (e.g., received level and distance) to predict 
responses that are also driven by additional factors that cannot be 
easily incorporated into the thresholds (e.g., context). So, while the 
behavioral harassment thresholds have been refined here to better 
consider the best available science (e.g., incorporating both received 
level and distance), they also still have some built-in conservative 
factors to address the challenge noted. For example, while duration of 
observed responses in the data are now considered in the thresholds, 
some of the responses that are informing take thresholds are of a very 
short duration, such that it is possible some of these responses might 
not always rise to the level of disrupting behavior patterns to a point 
where they are abandoned or significantly altered. We describe the 
application of this behavioral harassment threshold as identifying the 
maximum number of instances in which marine mammals could be reasonably 
expected to experience a disruption in behavior patterns to a point 
where they are abandoned or significantly altered. In summary, we 
believe these behavioral

[[Page 46347]]

harassment thresholds are the most appropriate method for predicting 
Level B harassment by behavioral disturbance given the best available 
science and the associated uncertainty.
Hearing Impairment (TTS/PTS), Tissues Damage, and Mortality
    NMFS' Acoustic Technical Guidance (NMFS, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). The Acoustic Technical Guidance also 
identifies criteria to predict TTS, which is not considered injury and 
falls into the Level B harassment category. The Navy's planned activity 
includes the use of non-impulsive (sonar) and impulsive (explosives) 
sources. These thresholds (Tables 8 and 9) were developed by compiling 
and synthesizing the best available science and soliciting input 
multiple times from both the public and peer reviewers. The references, 
analysis, and methodology used in the development of the thresholds are 
described in Acoustic Technical Guidance, which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

  Table 8--Acoustic Thresholds Identifying the Onset of TTS and PTS for
        Non-Impulsive Sound Sources by Functional Hearing Groups
------------------------------------------------------------------------
                                                   Non-impulsive
                                         -------------------------------
        Functional hearing group           TTS Threshold   PTS threshold
                                          SEL (weighted)  SEL (weighted)
------------------------------------------------------------------------
Low-Frequency Cetaceans.................             179             199
Mid-Frequency Cetaceans.................             178             198
High-Frequency Cetaceans................             153             173
------------------------------------------------------------------------
Note: SEL thresholds in dB re 1 [mu]Pa\2\s.

    Based on the best available science, the Navy (in coordination with 
NMFS) used the acoustic and pressure thresholds indicated in Table 9 to 
predict the onset of TTS, PTS, tissue damage, and mortality for 
explosives (impulsive) and other impulsive sound sources.

            Table 9--Onset of TTS, PTS, Tissue Damage, and Mortality Thresholds for Marine Mammals for Explosives and Other Impulsive Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                               Mean onset slight   Mean onset slight      Mean onset
    Functional hearing group            Species            Onset TTS           Onset PTS        GI tract injury       lung injury          mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans.........  All mysticetes....  168 dB SEL          183 dB SEL          237 dB Peak SPL...  Equation 1........  Equation 2.
                                                       (weighted) or 213   (weighted). or
                                                       dB Peak SPL.        219 dB Peak SPL.
Mid-frequency cetaceans.........  Most delphinids,    170 dB SEL          185 dB SEL          237 dB Peak SPL...
                                   medium and large    (weighted) or 224   (weighted) or 230
                                   toothed whales.     dB Peak SPL.        dB Peak SPL.
High-frequency cetaceans........  Porpoises and       140 dB SEL          155 dB SEL          237 dB Peak SPL...
                                   Kogia spp..         (weighted) or 196   (weighted) or 202
                                                       dB Peak SPL.        dB Peak SPL.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
Equation 1: 47.5M\1/3\ (1+[D\Rm\/10.1])\1/6\ Pa-sec.
Equation 2: 103M\1/3\ (1+[D\Rm\/10.1])\1/6\ Pa-sec.
M = mass of the animals in kg.
D\Rm\ = depth of the receiver (animal) in meters.
SPL = sound pressure level.

    The criteria used to assess the onset of TTS and PTS due to 
exposure to sonars (non-impulsive, see Table 8 above) are discussed 
further in the Navy's rulemaking/LOA application (see Hearing Loss from 
Sonar and Other Transducers in Section 6, Section 6.4.2.1, Methods for 
Analyzing Impacts from Sonars and Other Transducers). Refer to the 
Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects 
Analysis (Phase III) report (U.S. Department of the Navy, 2017c) for 
detailed information on how the criteria and thresholds were derived. 
Non-auditory injury (i.e., other than PTS) and mortality from sonar and 
other transducers is so unlikely as to be discountable under normal 
conditions for the reasons explained in the proposed rule under the 
Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat section--Acoustically Mediated Bubble Growth and other 
Pressure-related Injury, and is therefore not considered further in 
this analysis. As noted previously, additional information and analysis 
has been added to the Potential Effects of Specified Activities on 
Marine Mammals and Their Habitat section of this final rule 
specifically addressing and ruling out the likelihood of mortality of 
beaked whales through strandings associated with sonar exposure.
    The mitigation measures associated with explosives are expected to 
be effective in preventing tissue damage to

[[Page 46348]]

any potentially affected species, and when considered in combination 
with the modeled exposure results, no species are anticipated to incur 
tissue damage during the period of this rule. Tables 26 indicate the 
range to effects for tissue damage for different explosive types. The 
Navy will implement mitigation measures (described in the Mitigation 
Measures section) during explosive activities, including delaying 
detonations when a marine mammal is observed in the mitigation zone. 
Nearly all explosive events will occur during daylight hours to improve 
the sightability of marine mammals and thereby improve mitigation 
effectiveness. Observing for marine mammals during the explosive 
activities will include visual and passive acoustic detection methods 
(when they are available and part of the activity) before the activity 
begins, in order to cover the mitigation zones that can range from 200 
yds (183 m) to 2,500 yds (2,286 m) depending on the source (e.g., 
explosive sonobuoy, explosive torpedo, explosive bombs), and 2.5 nmi 
for sinking exercise (see Tables 34-39).
Level B Harassment by Behavioral Disturbance
    Though significantly driven by received level, the onset of Level B 
harassment by behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source (e.g., frequency, predictability, duty cycle), the environment 
(e.g., bathymetry), and the receiving animals (hearing, motivation, 
experience, demography, behavioral context) and can be difficult to 
predict (Ellison et al., 2011; Southall et al., 2007). Based on what 
the available science indicates and the practical need to use 
thresholds based on a factor, or factors, that are both predictable and 
measurable for most activities, NMFS uses generalized acoustic 
thresholds based primarily on received level (and distance in some 
cases) to estimate the onset of Level B harassment by behavioral 
disturbance.
    Sonar--As noted above, the Navy coordinated with NMFS to develop, 
and propose for use in this rule, behavioral harassment thresholds 
specific to their military readiness activities utilizing active sonar. 
These behavioral harassment thresholds consist of behavioral response 
functions (BRFs) and associated cutoff distances, and are also referred 
to, together, as ``the criteria.'' These criteria are used to estimate 
the number of animals that may exhibit a behavioral response that rises 
to the level of a take when exposed to sonar and other transducers. The 
way the criteria were derived is discussed in detail in the Criteria 
and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis 
(Phase III) report (U.S. Department of the Navy, 2017c). Developing 
these behavioral harassment thresholds involved multiple steps. All 
peer-reviewed published behavioral response studies conducted both in 
the field and on captive animals were examined in order to understand 
the breadth of behavioral responses of marine mammals to sonar and 
other transducers. NMFS has carefully reviewed the Navy's criteria, 
i.e., BRFs and cutoff distances for the species, and agrees that they 
are the best available science and the appropriate method to use at 
this time for determining impacts to marine mammals from sonar and 
other transducers and for calculating take and to support the 
determinations made in this rule. The Navy and NMFS will continue to 
evaluate the information as new science becomes available. The criteria 
have been rigorously vetted within the Navy community, among scientists 
during expert elicitation, and then reviewed by the public before being 
applied. It is not necessary or possible to revise and update the 
criteria and risk functions every time a new paper is published. The 
Navy is considering new information as it becomes available for updates 
to the criteria in the future, when the next round of updated criteria 
will be developed. Thus far, no new information has been published or 
otherwise conveyed that would fundamentally change the assessment of 
impacts or conclusions of the 2020 MITT FSEIS/OEIS or this rule.
    As discussed above, marine mammal responses to sound (some of which 
are considered disturbances that rise to the level of a take) are 
highly variable and context specific, i.e., they are affected by 
differences in acoustic conditions; differences between species and 
populations; differences in gender, age, reproductive status, or social 
behavior; or other prior experience of the individuals. This means that 
there is support for considering alternative approaches for estimating 
Level B harassment by behavioral disturbance. Although the statutory 
definition of Level B harassment for military readiness activities 
states that a natural behavior pattern of a marine mammal is 
significantly altered or abandoned, the current state of science for 
determining those thresholds is somewhat unsettled.
    In its analysis of impacts associated with sonar acoustic sources 
(which was coordinated with NMFS), the Navy used an updated 
conservative approach that likely overestimates the number of takes by 
Level B harassment due to behavioral disturbance and response. Many of 
the behavioral responses identified using the Navy's quantitative 
analysis are most likely to be of moderate severity as described in the 
Southall et al. (2007) behavioral response severity scale. These 
``moderate'' severity responses were considered significant if they 
were sustained for the duration of the exposure or longer. Within the 
Navy's quantitative analysis, many reactions are predicted from 
exposure to sound that may exceed an animal's threshold for Level B 
harassment by behavioral disturbance for only a single exposure (a few 
seconds) to several minutes, and it is likely that some of the 
resulting estimated behavioral responses that are counted as Level B 
harassment would not constitute significant alteration or abandonment 
of the natural behavioral patterns. The Navy and NMFS have used the 
best available science to address the challenging differentiation 
between significant and non-significant behavioral reactions (i.e., 
whether the behavior has been abandoned or significantly altered such 
that it qualifies as harassment), but have erred on the cautious side 
where uncertainty exists (e.g., counting these lower duration reactions 
as take), which likely results in some degree of overestimation of 
Level B harassment by behavioral disturbance. We consider application 
of these behavioral harassment thresholds, therefore, as identifying 
the maximum number of instances in which marine mammals could be 
reasonably expected to experience a disruption in behavior patterns to 
a point where they are abandoned or significantly altered (i.e., Level 
B harassment). Because this is the most appropriate method for 
estimating Level B harassment given the best available science and 
uncertainty on the topic, it is these numbers of Level B harassment by 
behavioral disturbance that are analyzed in the Analysis and Negligible 
Impact Determination section and are authorized.
    In the Navy's acoustic impact analyses during Phase II (the 
previous phase of Navy testing and training, 2015-2020; see also Navy's 
Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects 
Analysis Technical Report, 2012), the likelihood of Level B harassment 
by behavioral disturbance in response to sonar and other transducers 
was based on a probabilistic function (BRF) that related the likelihood 
(i.e., probability) of a behavioral response (at the level of a Level B 
harassment) to the received SPL. The BRF was used to estimate the 
percentage of an exposed population that is likely to exhibit Level

[[Page 46349]]

B harassment due to altered behaviors or behavioral disturbance at a 
given received SPL. This BRF relied on the assumption that sound poses 
a negligible risk to marine mammals if they are exposed to SPL below a 
certain ``basement'' value. Above the basement exposure SPL, the 
probability of a response increased with increasing SPL. Two BRFs were 
used in Navy acoustic impact analyses: BRF1 for mysticetes and BRF2 for 
other species. BRFs were not used for beaked whales during Phase II 
analyses. Instead, a step function at an SPL of 140 dB re 1 [mu]Pa was 
used for beaked whales as the threshold to predict Level B harassment 
by behavioral disturbance.
    Developing the criteria for Level B harassment by behavioral 
disturbance for Phase III (the current phase of Navy training and 
testing activities) involved multiple steps: all available behavioral 
response studies conducted both in the field and on captive animals 
were examined to understand the breadth of behavioral responses of 
marine mammals to sonar and other transducers (see also Navy's Criteria 
and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis 
(Phase III) Technical Report, 2017). Six behavioral response field 
studies with observations of 14 different marine mammal species 
reactions to sonar or sonar-like signals and 6 captive animal 
behavioral studies with observations of 8 different species reactions 
to sonar or sonar-like signals were used to provide a robust data set 
for the derivation of the Navy's Phase III marine mammal behavioral 
response criteria. All behavioral response research that has been 
published since the derivation of the Navy's Phase III criteria (c.a. 
December 2016) has been examined and is consistent with the current 
behavioral response functions. Marine mammal species were placed into 
behavioral criteria groups based on their known or suspected behavioral 
sensitivities to sound. In most cases these divisions were driven by 
taxonomic classifications (e.g., mysticetes, pinnipeds). The data from 
the behavioral studies were analyzed by looking for significant 
responses, or lack thereof, for each experimental session. The 
resulting four Bayesian Biphasic Dose Response Functions (referred to 
as the BRFs) that were developed for odontocetes, pinnipeds, 
mysticetes, and beaked whales predict the probability of a behavioral 
response qualifying as Level B harassment given exposure to certain 
received levels of sound. These BRFs are then used in combination with 
the cutoff distances described below to estimate the number of takes by 
Level B harassment.
    The Navy used cutoff distances beyond which the potential of 
significant behavioral responses (and therefore Level B harassment) is 
considered to be unlikely (see Table 10 below). This was determined by 
examining all available published field observations of behavioral 
reactions to sonar or sonar-like signals that included the distance 
between the sound source and the marine mammal. The longest distance, 
rounded up to the nearest 5-km increment, was chosen as the cutoff 
distance for each behavioral criteria group (i.e., odontocetes, 
mysticetes, and beaked whales). For animals within the cutoff distance, 
a behavioral response function based on a received SPL as presented in 
Section 3, Section 3.1.0 of the Navy's rulemaking/LOA application was 
used to predict the probability of a potential significant behavioral 
response. For training and testing events that contain multiple 
platforms or tactical sonar sources that exceed 215 dB re 1 [micro]Pa 
@1 m, this cutoff distance is substantially increased (i.e., doubled) 
from values derived from the literature. The use of multiple platforms 
and intense sound sources (high source level) are factors that probably 
increase responsiveness in marine mammals overall (however, we note 
that helicopter dipping sonars were considered in the intense sound 
source group, despite lower source levels, because of data indicating 
that marine mammals are sometimes more responsive to the less 
predictable employment of this source). There are currently few 
behavioral observations under these circumstances; therefore, the Navy 
conservatively predicted significant behavioral responses that will 
rise to Level B harassment at farther ranges as shown in Table 10, 
versus less intense events.

  Table 10--Cutoff Distances for Moderate Source Level, Single Platform
   Training and Testing Events and for all Other Events With Multiple
    Platforms or Sonar With Source Levels at or Exceeding 215 dB re 1
                             [micro]Pa @1 m
------------------------------------------------------------------------
                                           Moderate SL/
                                              single      High SL/ multi-
             Criteria group                  platform        platform
                                              cutoff          cutoff
                                           distance (km)   distance (km)
------------------------------------------------------------------------
Odontocetes.............................              10              20
Mysticetes..............................              10              20
Beaked Whales...........................              25              50
------------------------------------------------------------------------
Note: dB re 1 [micro]Pa @1 m = decibels referenced to 1 micropascal at 1
  meter; km = kilometer; SL = source level.

    The range to received sound levels in 6-dB steps from five 
representative sonar bins and the percentage of animals that may be 
taken by Level B harassment at the received level and distance 
indicated under each behavioral response function are shown in Table 11 
through Table 15. Cells are shaded if the mean range value for the 
specified received level exceeds the distance cutoff range for a 
particular hearing group and therefore are not included in the 
estimated take. See Section 6, Section 6.4.2.1.1 (Methods for Analyzing 
Impacts from Sonars and Other Transducers) of the Navy's rulemaking/LOA 
application for further details on the derivation and use of the 
behavioral response functions, thresholds, and the cutoff distances to 
identify takes by Level B harassment, which were coordinated with NMFS. 
Table 11 illustrates the maximum likely percentage of exposed 
individuals taken at the indicated received level and associated range 
(in which marine mammals would be reasonably expected to experience a 
disruption in behavior patterns to a point where they are abandoned or 
significantly altered) for LFAS. As noted previously, NMFS carefully 
reviewed, and contributed to, the Navy's behavioral harassment 
thresholds (i.e., the BRFs and the cutoff distances) for the species, 
and agrees that these methods represent the best available science at 
this time for determining impacts to marine mammals from sonar and 
other transducers.
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    Tables 12 through 15 identify the maximum likely percentage of 
exposed individuals taken at the indicated received level and 
associated range for MFAS.

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       Table 15--Ranges to Estimated Level B Harassment by Behavioral Disturbance for Sonar Bin HF4 Over a
                         Representative Range of Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                       Probability of level B harassment by
                                       Average range (m) with        behavioral disturbance for sonar bin HF4
 Received level (dB re 1 [mu]Pa)   minimum and maximum values in -----------------------------------------------
                                            parenthesis             Odontocetes     Mysticetes
                                                                     (percent)       (percent)     Beaked whales
----------------------------------------------------------------------------------------------------------------
196..............................  3 (2-4)......................             100             100             100
190..............................  8 (6-10).....................             100              98             100
184..............................  16 (12-20)...................              99              88             100
178..............................  32 (24-40)...................              97              59             100
172..............................  63 (45-80)...................              91              30              99
166..............................  120 (75-160).................              78              20              97
160..............................  225 (120-310)................              58              18              93
154..............................  392 (180-550)................              40              17              83
148..............................  642 (280-1,275)..............              29              16              66
142..............................  916 (420-1,775)..............              25              13              45
136..............................  1,359 (625-2,525)............              23               9              28
130..............................  1,821 (950-3,275)............              20               5              18
124..............................  2,567 (1,275-5,025)..........              17               2              14
118..............................  3,457 (1,775-6,025)..........              12               1              12
112..............................  4,269 (2,275-7,025)..........               6               0              11
106..............................  5,300 (3,025-8,025)..........               3               0              11
100..............................  6,254 (3,775-9,275)..........               1               0               8
----------------------------------------------------------------------------------------------------------------
Notes: dB re 1 [mu]Pa = decibels referenced to 1 micropascal, m = meters.

    Explosives--Phase III explosive thresholds for Level B harassment 
by behavioral disturbance for marine mammals is the hearing groups' TTS 
threshold minus 5 dB (see Table 16 below and Table 9 for the TTS 
thresholds for explosives) for events that contain multiple impulses 
from explosives underwater. This was the same approach as taken in 
Phase II for explosive analysis. See the Criteria and Thresholds for 
U.S. Navy Acoustic and Explosive Effects Analysis (Phase III) report 
(U.S. Department of the Navy, 2017c) for detailed information on how 
the criteria and thresholds were derived. NMFS continues to concur that 
this approach represents the best available science for determining 
impacts to marine mammals from explosives.

  Table 16--Thresholds for Level B Harassment by Behavioral Disturbance
                    for Explosives for Marine Mammals
------------------------------------------------------------------------
                                    Functional hearing
             Medium                        group          SEL (weighted)
------------------------------------------------------------------------
Underwater......................  LF                                 163
Underwater......................  MF                                 165
Underwater......................  HF                                 135
------------------------------------------------------------------------
Note: Weighted SEL thresholds in dB re 1 [mu]Pa\2\s underwater.


[[Page 46358]]

Navy's Acoustic Effects Model

    The Navy's Acoustic Effects Model calculates sound energy 
propagation from sonar and other transducers and explosives during 
naval activities and the sound received by animat dosimeters. Animat 
dosimeters are virtual representations of marine mammals distributed in 
the area around the modeled naval activity and each dosimeter records 
its individual sound ``dose.'' The model bases the distribution of 
animats over the MITT Study Area on the density values in the Navy 
Marine Species Density Database and distributes animats in the water 
column proportional to the known time that species spend at varying 
depths.
    The model accounts for environmental variability of sound 
propagation in both distance and depth when computing the received 
sound level received by the animats. The model conducts a statistical 
analysis based on multiple model runs to compute the estimated effects 
on animals. The number of animats that exceed the thresholds for 
effects is tallied to provide an estimate of the number of marine 
mammals that could be affected.
    Assumptions in the Navy model intentionally err on the side of 
overestimation when there are unknowns. Naval activities are modeled as 
though they would occur regardless of proximity to marine mammals, 
meaning that no mitigation is considered (i.e., no power down or shut 
down modeled) and without any avoidance of the activity by the animal. 
The final step of the quantitative analysis of acoustic effects is to 
consider the implementation of mitigation and the possibility that 
marine mammals would avoid continued or repeated sound exposures. For 
more information on this process, see the discussion in the Take 
Estimation subsection below. Many explosions from ordnance such as 
bombs and missiles actually occur upon impact with above-water targets. 
However, for this analysis, sources such as these were modeled as 
exploding underwater, which overestimates the amount of explosive and 
acoustic energy entering the water.
    The model estimates the impacts caused by individual training and 
testing exercises. During any individual modeled event, impacts to 
individual animats are considered over 24-hour periods. The animats do 
not represent actual animals, but rather they represent a distribution 
of animals based on density and abundance data, which allows for a 
statistical analysis of the number of instances that marine mammals may 
be exposed to sound levels resulting in an effect. Therefore, the model 
estimates the number of instances in which an effect threshold was 
exceeded over the course of a year, but does not estimate the number of 
individual marine mammals that may be impacted over a year (i.e., some 
marine mammals could be impacted several times, while others would not 
experience any impact). A detailed explanation of the Navy's Acoustic 
Effects Model is provided in the technical report Quantifying Acoustic 
Impacts on Marine Mammals and Sea Turtles: Methods and Analytical 
Approach for Phase III Training and Testing report (U.S. Department of 
the Navy, 2018).

Range to Effects

    The following section provides range to effects for sonar and other 
active acoustic sources, as well as explosives, to specific acoustic 
thresholds determined using the Navy Acoustic Effects Model. Marine 
mammals exposed within these ranges for the shown duration are 
predicted to experience the associated effect. Range to effects is 
important information in not only predicting acoustic impacts, but also 
in verifying the accuracy of model results against real-world 
situations and determining adequate mitigation ranges to avoid higher 
level effects, especially physiological effects to marine mammals.
Sonar
    The range to received sound levels in 6-dB steps from five 
representative sonar bins and the percentage of the total number of 
animals that may exhibit a significant behavioral response (and 
therefore Level B harassment) under each behavioral response function 
are shown in Table 11 through Table 15 above, respectively. See Section 
6, Section 6.4.2.1 (Methods for Analyzing Impacts from Sonars and Other 
Transducers) of the Navy's rulemaking/LOA application for additional 
details on the derivation and use of the behavioral response functions, 
thresholds, and the cutoff distances that are used to identify Level B 
harassment by behavioral disturbance. NMFS has reviewed the range 
distance to effect data provided by the Navy and concurs with the 
analysis.
    The ranges to PTS for five representative sonar systems for an 
exposure of 30 seconds is shown in Table 17 relative to the marine 
mammal's functional hearing group. This period (30 seconds) was chosen 
based on examining the maximum amount of time a marine mammal would 
realistically be exposed to levels that could cause the onset of PTS 
based on platform (e.g., ship) speed and a nominal animal swim speed of 
approximately 1.5 m per second. The ranges provided in the table 
include the average range to PTS, as well as the range from the minimum 
to the maximum distance at which PTS is possible for each hearing 
group.

           Table 17--Range to Permanent Threshold Shift (Meters) for Five Representative Sonar Systems
----------------------------------------------------------------------------------------------------------------
                                          Approximate range in meters for PTS from 30 second exposure \1\
          Hearing group          -------------------------------------------------------------------------------
                                   Sonar bin HF4   Sonar bin LF4   Sonar bin MF1   Sonar bin MF4   Sonar bin MF5
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans........      29 (22-35)         0 (0-0)   181 (180-190)      30 (30-30)        9 (8-10)
Low-frequency cetaceans.........         0 (0-0)         0 (0-0)      65 (65-65)      15 (15-15)         0 (0-0)
Mid-frequency cetaceans.........         1 (0-1)         0 (0-0)      16 (16-16)         3 (3-3)         0 (0-0)
----------------------------------------------------------------------------------------------------------------
\1\ PTS ranges extend from the sonar or other active acoustic sound source to the indicated distance. The
  average range to PTS is provided as well as the range from the estimated minimum to the maximum range to PTS
  in parenthesis.

    The tables below illustrate the range to TTS for 1, 30, 60, and 120 
seconds from five representative sonar systems (see Table 18 through 
Table 22).

[[Page 46359]]



     Table 18--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin LF4 Over a Representative Range of
                                     Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                Approximate TTS ranges (meters) \1\
                                                 ---------------------------------------------------------------
                  Hearing group                                            Sonar bin LF4
                                                 ---------------------------------------------------------------
                                                     1 second       30 seconds      60 seconds      120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans........................         0 (0-0)         0 (0-0)         0 (0-0)         0 (0-0)
Low-frequency cetaceans.........................         3 (3-3)         4 (4-4)         6 (6-6)         9 (9-9)
Mid-frequency cetaceans.........................         0 (0-0)         0 (0-0)         0 (0-0)         0 (0-0)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
  zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
  average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
  in parentheses.


     Table 19--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin MF1 Over a Representative Range of
                                     Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
                                                      Approximate TTS ranges (meters) \1\
                             -----------------------------------------------------------------------------------
        Hearing group                                            Sonar Bin MF1
                             -----------------------------------------------------------------------------------
                                    1 second            30 seconds           60 seconds          120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans....  3,181 (2,025-5,025)  3,181 (2,025-5,025)  5,298 (2,275-7,775)  6,436 (2,525-9,775)
Low-frequency cetaceans.....      898 (850-1,025)      898 (850-1,025)  1,271 (1,025-1,525)  1,867 (1,275-3,025)
Mid-frequency cetaceans.....        210 (200-210)        210 (200-210)        302 (300-310)        377 (370-390)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
  zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
  average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
  in parentheses.
Note: Ranges for 1-second and 30-second periods are identical for Bin MF1 because this system nominally pings
  every 50 seconds; therefore, these periods encompass only a single ping.


     Table 20--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin MF4 Over a Representative Range of
                                     Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
                                                               Approximate TTS ranges (meters) \1\
                                               -----------------------------------------------------------------
                 Hearing group                                            Sonar bin MF4
                                               -----------------------------------------------------------------
                                                   1 second       30 seconds      60 seconds       120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans......................   232 (220-260)   454 (420-600)   601 (575-875)   878 (800-1,525)
Low-frequency cetaceans.......................      85 (85-90)   161 (160-170)   229 (220-250)     352 (330-410)
Mid-frequency cetaceans.......................      22 (22-22)      35 (35-35)      50 (45-50)        70 (70-70)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
  zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
  average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
  in parentheses.


     Table 21--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin MF5 Over a Representative Range of
                                     Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                Approximate TTS ranges (meters) \1\
                                                 ---------------------------------------------------------------
                  Hearing group                                            Sonar bin MF5
                                                 ---------------------------------------------------------------
                                                     1 second       30 seconds      60 seconds      120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans........................   114 (110-130)   114 (110-130)   168 (150-200)   249 (210-290)
Low-frequency cetaceans.........................      11 (10-12)      11 (10-12)      16 (16-17)      23 (23-24)
Mid-frequency cetaceans.........................         5 (0-9)         5 (0-9)      12 (11-13)      18 (17-18)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
  zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
  average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
  in parentheses.


[[Page 46360]]


     Table 22--Ranges to Temporary Threshold Shift (Meters) for Sonar Bin HF4 Over a Representative Range of
                                     Environments Within the MITT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                Approximate TTS ranges (meters) \1\
                                                 ---------------------------------------------------------------
                  Hearing group                                            Sonar bin HF4
                                                 ---------------------------------------------------------------
                                                     1 second       30 seconds      60 seconds      120 seconds
----------------------------------------------------------------------------------------------------------------
High-frequency cetaceans........................   155 (110-210)   259 (180-350)   344 (240-480)   445 (300-600)
Low-frequency cetaceans.........................         1 (0-2)         2 (1-3)         4 (3-5)         7 (5-8)
Mid-frequency cetaceans.........................       10 (7-12)      17 (12-21)      24 (17-30)      33 (25-40)
----------------------------------------------------------------------------------------------------------------
\1\ Ranges to TTS represent the model predictions in different areas and seasons within the MITT Study Area. The
  zone in which animals are expected to experience TTS extend from onset-PTS to the distance indicated. The
  average range to TTS is provided as well as the range from the estimated minimum to the maximum range to TTS
  in parentheses.

Explosives
    The following section provides the range (distance) over which 
specific physiological or behavioral effects are expected to occur 
based on the explosive criteria (see Section 6, Section 6.5.2.1.1 of 
the Navy's rulemaking/LOA application and the Criteria and Thresholds 
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III) 
report (U.S. Department of the Navy, 2017c)) and the explosive 
propagation calculations from the Navy Acoustic Effects Model (see 
Section 6, Section 6.5.2.1.3, Navy Acoustic Effects Model of the Navy's 
rulemaking/LOA application). The range to effects are shown for a range 
of explosive bins, from E1 (up to 0.25 lb net explosive weight) to E12 
(up to 1,000 lb net explosive weight) (Tables 23 through 27). Ranges 
are determined by modeling the distance that noise from an explosion 
would need to propagate to reach exposure level thresholds specific to 
a hearing group that would cause behavioral response (to the degree of 
Level B harassment), TTS, PTS, and non-auditory injury. Ranges are 
provided for a representative source depth and cluster size for each 
bin. For events with multiple explosions, sound from successive 
explosions can be expected to accumulate and increase the range to the 
onset of an impact based on SEL thresholds. Ranges to non-auditory 
injury and mortality are shown in Tables 26 and 27, respectively. NMFS 
has reviewed the range distance to effect data provided by the Navy and 
concurs with the analysis. For additional information on how ranges to 
impacts from explosions were estimated, see the technical report 
Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods 
and Analytical Approach for Phase III Training and Testing (U.S. Navy, 
2018).
    Table 23 shows the minimum, average, and maximum ranges to onset of 
auditory and likely behavioral effects that rise to the level of Level 
B harassment for high-frequency cetaceans based on the developed 
thresholds.

       Table 23--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance for High-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Range to effects for explosives bin: high-frequency cetaceans \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Source Depth
                     Bin                             (m)        Cluster Size             PTS                      TTS             Behavioral disturbance
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1...........................................             0.1               1            353 (340-370)      1,303 (1,275-1,775)      2,139 (2,025-4,275)
                                               ..............              18      1,031 (1,025-1,275)      3,409 (2,525-8,025)     4,208 (3,025-11,525)
E2...........................................             0.1               1            431 (410-700)      1,691 (1,525-2,775)      2,550 (2,025-4,525)
                                               ..............               5          819 (775-1,275)      2,896 (2,275-6,775)     3,627 (2,525-10,275)
E3...........................................             0.1               1            649 (625-700)      2,439 (2,025-4,525)      3,329 (2,525-7,525)
                                               ..............              12      1,682 (1,525-2,275)     4,196 (3,025-11,525)     5,388 (4,525-16,275)
                                                        18.25               1            720 (675-775)      4,214 (2,275-6,275)      7,126 (3,525-8,775)
                                               ..............              12      1,798 (1,525-2,775)    10,872 (4,525-13,775)    14,553 (5,525-17,775)
E4...........................................              10               2      1,365 (1,025-2,775)     7,097 (4,275-10,025)     9,939 (5,025-15,275)
                                                           60               2        1,056 (875-2,275)      3,746 (2,775-5,775)      5,262 (3,025-7,775)
E5...........................................             0.1              20      2,926 (1,525-6,275)     6,741 (4,525-16,025)     9,161 (4,775-20,025)
                                                           30              20      4,199 (3,025-6,275)    13,783 (8,775-17,775)   17,360 (10,525-22,775)
E6...........................................             0.1               1      1,031 (1,025-1,275)      3,693 (2,025-8,025)     4,659 (3,025-12,775)
                                                           30               1      1,268 (1,025-1,275)      7,277 (3,775-8,775)    10,688 (5,275-12,525)
E8...........................................             0.1               1      1,790 (1,775-3,025)     4,581 (4,025-10,775)     6,028 (4,525-15,775)
                                                        45.75               1      1,842 (1,525-2,025)     9,040 (4,525-12,775)    12,729 (5,025-18,525)
E9...........................................             0.1               1      2,343 (2,275-4,525)     5,212 (4,025-13,275)     7,573 (5,025-17,025)
E10..........................................             0.1               1      2,758 (2,275-5,025)     6,209 (4,275-16,525)     8,578 (5,275-19,775)
E11..........................................           45.75               1      3,005 (2,525-3,775)    11,648 (5,025-18,775)    14,912 (6,525-24,775)
                                                         91.4               1      3,234 (2,525-4,525)     5,772 (4,775-11,775)     7,197 (5,775-14,025)
E12..........................................             0.1               1      3,172 (3,025-6,525)     7,058 (5,025-17,025)     9,262 (6,025-21,775)
                                               ..............               4     4,209 (3,775-10,025)     9,817 (6,275-22,025)    12,432 (7,525-27,775)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to PTS, TTS, and behavioral disturbance thresholds are depicted above the minimum and maximum distances which are in
  parentheses. Values depict the range produced by SEL hearing threshold criteria levels.

    Table 24 shows the minimum, average, and maximum ranges to onset of 
auditory and likely behavioral effects that rise to the level of Level 
B harassment for mid-frequency cetaceans based on the developed 
thresholds.

[[Page 46361]]



        Table 24--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance for Mid-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Range to effects for explosives bin: mid-frequency cetaceans \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Source depth
                     Bin                             (m)        Cluster size             PTS                      TTS             Behavioral disturbance
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1...........................................             0.1               1               25 (25-25)            116 (110-120)            199 (190-210)
                                                                           18              94 (90-100)            415 (390-440)            646 (525-700)
E2...........................................             0.1               1               30 (30-35)            146 (140-170)            248 (230-370)
                                                                            5               63 (60-70)            301 (280-410)            481 (430-675)
E3...........................................             0.1               1               50 (50-50)            233 (220-250)            381 (360-400)
                                                                           12            155 (150-160)            642 (525-700)          977 (700-1,025)
                                                        18.25               1               40 (40-40)            202 (190-220)            332 (320-350)
                                                                           12            126 (120-130)            729 (675-775)      1,025 (1,025-1,025)
E4...........................................              10               2               76 (70-90)            464 (410-550)            783 (650-975)
                                                           60               2               60 (60-60)            347 (310-675)            575 (525-900)
E5...........................................             0.1              20            290 (280-300)        1,001 (750-1,275)        1,613 (925-3,275)
                                                           30              20            297 (240-420)      1,608 (1,275-2,775)      2,307 (2,025-2,775)
E6...........................................             0.1               1              98 (95-100)            430 (400-450)            669 (550-725)
                                                           30               1               78 (75-80)            389 (370-410)            619 (600-650)
E8...........................................             0.1               1            162 (150-170)            665 (550-700)          982 (725-1,025)
                                                        45.75               1            127 (120-130)            611 (600-625)          985 (950-1,025)
E9...........................................             0.1               1            215 (210-220)          866 (625-1,000)        1,218 (800-1,525)
E10..........................................             0.1               1            270 (250-280)          985 (700-1,275)        1,506 (875-2,525)
E11..........................................           45.75               1            241 (230-250)      1,059 (1,000-1,275)      1,874 (1,525-2,025)
                                                         91.4               1            237 (230-270)        1,123 (900-2,025)      1,731 (1,275-2,775)
E12..........................................             0.1               1            332 (320-370)        1,196 (825-1,525)      1,766 (1,025-3,525)
                                                                            4            572 (500-600)      1,932 (1,025-4,025)      2,708 (1,275-6,775)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to PTS, TTS, and behavioral disturbance thresholds are depicted above the minimum and maximum distances which are in
  parentheses. Values depict the range produced by SEL hearing threshold criteria levels.

    Table 25 shows the minimum, average, and maximum ranges to onset of 
auditory and likely behavioral effects that rise to the level of Level 
B harassment for low-frequency cetaceans based on the developed 
thresholds.

        Table 25--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance for Low-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Range to effects for explosives bin: low-frequency cetaceans \1\
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Source depth
                     Bin                             (m)        Cluster size             PTS                      TTS             Behavioral disturbance
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1...........................................             0.1               1               51 (50-55)            231 (200-250)            378 (280-410)
                                                                           18            183 (170-190)            691 (450-775)          934 (575-1,275)
E2...........................................             0.1               1               66 (65-70)            291 (220-320)            463 (330-500)
                                                                            5            134 (110-140)            543 (370-600)            769 (490-950)
E3...........................................             0.1               1            113 (110-120)            477 (330-525)            689 (440-825)
                                                                           12            327 (250-370)          952 (600-1,525)        1,240 (775-4,025)
                                                        18.25               1            200 (200-200)          955 (925-1,000)      1,534 (1,275-1,775)
                                                                           12            625 (600-625)      5,517 (2,275-7,775)    10,299 (3,775-13,025)
E4...........................................              10               2            429 (370-600)      2,108 (1,775-2,775)      4,663 (3,025-6,025)
                                                           60               2            367 (340-470)      1,595 (1,025-2,025)      2,468 (1,525-4,275)
E5...........................................             0.1              20          702 (380-1,275)       1,667 (850-11,025)     2,998 (1,025-19,775)
                                                           30              20      1,794 (1,275-2,775)     8,341 (3,775-11,525)    13,946 (4,025-22,275)
E6...........................................             0.1               1            250 (190-410)          882 (480-1,775)        1,089 (625-6,525)
                                                           30               1            495 (490-500)      2,315 (2,025-2,525)      5,446 (3,275-6,025)
E8...........................................             0.1               1            415 (270-725)        1,193 (625-4,275)        1,818 (825-8,525)
                                                        45.75               1            952 (900-975)      6,294 (3,025-9,525)    12,263 (4,275-20,025)
E9...........................................             0.1               1          573 (320-1,025)        1,516 (725-7,275)       2,411 (950-14,275)
E10..........................................             0.1               1          715 (370-1,525)       2,088 (825-28,275)     4,378 (1,025-32,275)
E11..........................................           45.75               1      1,881 (1,525-2,275)    12,425 (4,275-27,275)    23,054 (7,025-65,275)
                                                         91.4               1      1,634 (1,275-2,525)     5,686 (3,775-11,275)    11,618 (5,525-64,275)
E12..........................................             0.1               1          790 (420-2,775)       2,698 (925-25,275)     6,032 (1,025-31,275)
                                                                            4        1,196 (575-6,025)     6,876 (1,525-31,275)    13,073 (3,775-64,275)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to PTS, TTS, and behavioral disturbance thresholds are depicted above the minimum and maximum distances which are in
  parentheses. Values depict the range produced by SEL hearing threshold criteria levels.

    Table 26 shows the minimum, average, and maximum ranges due to 
varying propagation conditions to non-auditory injury as a function of 
animal mass and explosive bin (i.e., net explosive weight). Ranges to 
gastrointestinal tract injury typically exceed ranges to slight lung 
injury; therefore, the maximum range to effect

[[Page 46362]]

is not mass-dependent. Animals within these water volumes would be 
expected to receive minor injuries at the outer ranges, increasing to 
more substantial injuries, and finally mortality as an animal 
approaches the detonation point.

   Table 26--Ranges \1\ to 50 Percent Non-Auditory Injury Risk for All
                      Marine Mammal Hearing Groups
------------------------------------------------------------------------
                                                          Range (m) (min-
                           Bin                                 max)
------------------------------------------------------------------------
1.......................................................      12 (11-13)
E2......................................................      16 (15-16)
E3......................................................      25 (25-25)
E4......................................................      30 (30-35)
E5......................................................      40 (40-65)
E6......................................................      52 (50-60)
E8......................................................     98 (90-150)
E9......................................................   123 (120-270)
E10.....................................................   155 (150-430)
E11.....................................................   418 (410-420)
E12.....................................................   195 (180-675)
------------------------------------------------------------------------
\1\ Distances in meters (m). Average distance is shown with the minimum
  and maximum distances due to varying propagation environments in
  parentheses.
Note: All ranges to non-auditory injury within this table are driven by
  gastrointestinal tract injury thresholds regardless of animal mass.

    Ranges to mortality, based on animal mass, are shown in Table 27 
below.

                   Table 27--Ranges \1\ to 50 Percent Mortality Risk for All Marine Mammal Hearing Groups as a Function of Animal Mass
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Range to mortality (meters) for various animal mass intervals (kg) \1\
                           Bin                           -----------------------------------------------------------------------------------------------
                                                                10              250            1,000           5,000          25,000          72,000
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1......................................................         3 (3-3)         1 (0-2)         0 (0-0)         0 (0-0)         0 (0-0)         0 (0-0)
E2......................................................         4 (3-4)         2 (1-3)         1 (0-1)         0 (0-0)         0 (0-0)         0 (0-0)
E3......................................................        9 (7-10)         4 (2-8)         2 (1-2)         1 (0-1)         0 (0-0)         0 (0-0)
E4......................................................      13 (12-15)        7 (4-12)         3 (3-4)         2 (1-3)         1 (1-1)         1 (0-1)
E5......................................................      13 (12-30)        7 (4-25)         3 (2-7)         2 (1-5)         1 (1-2)         1 (0-2)
E6......................................................      16 (15-25)        9 (5-23)         4 (3-8)         3 (2-6)         1 (1-2)         1 (1-2)
E8......................................................      42 (25-65)       22 (9-50)       11 (6-19)        8 (4-13)         4 (2-6)         3 (1-5)
E9......................................................      33 (30-35)      20 (13-30)       10 (9-12)         7 (5-9)         4 (3-4)         3 (2-3)
E10.....................................................     55 (40-170)      24 (16-35)      13 (11-15)        9 (7-11)         5 (4-5)         4 (3-4)
E11.....................................................   206 (200-210)     98 (55-170)      44 (35-50)      30 (25-35)      16 (14-18)      12 (10-15)
E12.....................................................     86 (50-270)     35 (20-210)      16 (13-19)       11 (9-13)         6 (5-6)         5 (4-5)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to mortality is depicted above the minimum and maximum distances, which are in parentheses.

Marine Mammal Density

    A quantitative analysis of impacts on a species or stock requires 
data on their abundance and distribution that may be affected by 
anthropogenic activities in the potentially impacted area. The most 
appropriate metric for this type of analysis is density, which is the 
number of animals present per unit area. Marine species density 
estimation requires a significant amount of effort to both collect and 
analyze data to produce a reasonable estimate. Unlike surveys for 
terrestrial wildlife, many marine species spend much of their time 
submerged, and are not easily observed. In order to collect enough 
sighting data to make reasonable density estimates, multiple 
observations are required, often in areas that are not easily 
accessible (e.g., far offshore). Ideally, marine mammal species 
sighting data would be collected for the specific area and time period 
(e.g., season) of interest and density estimates derived accordingly. 
However, in many places, poor weather conditions and high sea states 
prohibit the completion of comprehensive visual surveys.
    For most cetacean species, abundance is estimated using line-
transect surveys or mark-recapture studies (e.g., Barlow, 2010; Barlow 
and Forney, 2007; Calambokidis et al., 2008). The result provides one 
single density estimate value for each species across broad geographic 
areas. This is the general approach applied in estimating cetacean 
abundance in NMFS' SARs. Although the single value provides a good 
average estimate of abundance (total number of individuals) for a 
specified area, it does not provide information on the species 
distribution or concentrations within that area, and it does not 
estimate density for other timeframes or seasons that were not 
surveyed. More recently, spatial habitat modeling developed by NMFS' 
Southwest Fisheries Science Center has been used to estimate cetacean 
densities (Barlow et al., 2009; Becker et al., 2010, 2012a, b, c, 2014, 
2016; Ferguson et al., 2006a; Forney et al., 2012, 2015; Redfern et 
al., 2006). These models estimate cetacean density as a continuous 
function of habitat variables (e.g., sea surface temperature, seafloor 
depth, etc.) and thus allow predictions of cetacean densities on finer 
spatial scales than traditional line-transect or mark recapture 
analyses and for areas that have not been surveyed. Within the 
geographic area that was modeled, densities can be predicted wherever 
these habitat variables can be measured or estimated.
    Ideally, density data would be available for all species throughout 
the study area year-round, in order to best estimate the impacts of 
Navy activities on marine species. However, in many places, ship 
availability, lack of funding, inclement weather conditions, and high 
sea states prevent the completion of comprehensive year-round surveys. 
Even with surveys that are completed, poor conditions may result in 
lower sighting rates for species that would typically be sighted with 
greater frequency under favorable conditions. Lower sighting rates 
preclude having an acceptably low uncertainty in the density estimates. 
A high level of uncertainty, indicating a low level of confidence in 
the density estimate, is typical for species that are rare or difficult 
to sight. In areas where survey data are limited or non-existent, known 
or inferred associations between marine

[[Page 46363]]

habitat features and the likely presence of specific species are 
sometimes used to predict densities in the absence of actual animal 
sightings. Consequently, there is no single source of density data for 
every area, species, and season because of the fiscal costs, resources, 
and effort involved in providing enough survey coverage to consistently 
estimate density.
    To characterize marine species density for large oceanic regions, 
the Navy reviews, critically assesses, and prioritizes existing density 
estimates from multiple sources, requiring the development of a 
systematic method for selecting the most appropriate density estimate 
for each combination of species, area, and season. The selection and 
compilation of the best available marine species density data resulted 
in the Navy Marine Species Density Database (NMSDD). The Navy vetted 
all cetacean densities with NMFS prior to use in the Navy's acoustic 
analysis for this MITT rulemaking.
    A variety of density data and density models are needed in order to 
develop a density database that encompasses the entirety of the MITT 
Study Area. Because this data is collected using different methods with 
varying amounts of accuracy and uncertainty, the Navy has developed a 
hierarchy to ensure the most accurate data is used when available. The 
technical report titled U.S. Navy Marine Species Density Database Phase 
III for the Mariana Islands Training and Testing Study Area (U.S. 
Department of the Navy, 2018), hereafter referred to as the Density 
Technical Report, describes these models in detail and provides 
detailed explanations of the models applied to each species density 
estimate. The list below describes models in order of preference.
    1. Spatial density models are preferred and used when available 
because they provide an estimate with the least amount of uncertainty 
by deriving estimates for divided segments of the sampling area. These 
models (see Becker et al., 2016; Forney et al., 2015) predict spatial 
variability of animal presence as a function of habitat variables 
(e.g., sea surface temperature, seafloor depth, etc.). This model is 
developed for areas, species, and, when available, specific timeframes 
(months or seasons) with sufficient survey data; therefore, this model 
cannot be used for species with low numbers of sightings.
    2. Stratified design-based density estimates use line-transect 
survey data with the sampling area divided (stratified) into sub-
regions, and a density is predicted for each sub-region (see Barlow, 
2016; Becker et al., 2016; Bradford et al., 2017; Campbell et al., 
2014; Jefferson et al., 2014). While geographically stratified density 
estimates provide a better indication of a species' distribution within 
the study area, the uncertainty is typically high because each sub-
region estimate is based on a smaller stratified segment of the overall 
survey effort.
    3. Design-based density estimations use line-transect survey data 
from land and aerial surveys designed to cover a specific geographic 
area (see Carretta et al., 2015). These estimates use the same survey 
data as stratified design-based estimates, but are not segmented into 
sub-regions and instead provide one estimate for a large surveyed area. 
Although relative environmental suitability (RES) models provide 
estimates for areas of the oceans that have not been surveyed using 
information on species occurrence and inferred habitat associations and 
have been used in past density databases, these models were not used in 
the current quantitative analysis.
    Below we describe how densities were determined for the species in 
the MITT Study Area. In the MITT Study Area there is a paucity of line-
transect survey data, and little is known about the stock structure of 
the majority of marine mammal species in the region. The only habitat 
model available for the MITT Study Area was developed for sperm whales 
based on acoustic data collected during a 2007 line-transect survey 
(Yack et al., 2016). For other species, the Navy conducted the first 
comprehensive marine mammal survey of waters off Guam and the 
Commonwealth of the Northern Mariana Islands in 2007, and data from 
this survey were used to derive line-transect abundance estimates for 
12 cetacean species (Fulling et al., 2011). There has not been a 
subsequent systematic survey of the MITT Study Area at this scale, so 
these data still provide the best available density estimates for this 
region for these species.
    In the absence of study-area-specific density data, line-transect 
estimates derived for Hawaiian waters were used to provide conservative 
density estimates for the remaining species in the MITT Study Area. For 
Phase II, these estimates were based on systematic surveys conducted by 
NMFS' Southwest Fisheries Science Center (SWFSC) within the EEZ of the 
Hawaiian Islands (2010) and Palmyra Atoll/Kingman Reef (2011-2012) 
allowed NMFS' PIFSC to update the line-transect density estimates that 
included new sea-state-specific estimates of trackline detection 
probability (Bradford et al., 2017) and represent improvements to the 
estimates used for Phase II. In addition, an updated density estimate 
for minke whale was available for Phase III based on line-transect 
analyses of acoustic data collected from a towed hydrophone during the 
2007 systematic survey (Norris et al., 2017).
    The Navy developed a protocol and database to select the best 
available data sources based on species, area, and time (season). The 
resulting Geographic Information System database, used in the NMSDD, 
includes seasonal density values for every marine mammal species 
present within the MITT Study Area. This database is described in the 
Density Technical Report.
    The Navy describes some of the challenges of interpreting the 
results of the quantitative analysis summarized above and described in 
the Density Technical Report: ``It is important to consider that even 
the best estimate of marine species density is really a model 
representation of the values of concentration where these animals might 
occur. Each model is limited to the variables and assumptions 
considered by the original data source provider. No mathematical model 
representation of any biological population is perfect, and with 
regards to marine mammal biodiversity, any single model method will not 
completely explain the actual distribution and abundance of marine 
mammal species. It is expected that there would be anomalies in the 
results that need to be evaluated, with independent information for 
each case, to support if we might accept or reject a model or portions 
of the model (U.S. Department of the Navy, 2017a).''
    NMFS coordinated with the Navy in the development of its take 
estimates and concurs that the Navy's approach for density 
appropriately utilizes the best available science. Later, in the 
Analysis and Negligible Impact Determination section, we assess how the 
estimated take numbers compare to abundance in order to better 
understand the potential number of individuals impacted.

Take Estimation

    The 2020 MITT FSEIS/OEIS considered all training and testing 
activities planned to occur in the MITT Study Area that have the 
potential to result in the MMPA-defined take of marine mammals. The 
Navy determined that the two stressors below could result in the 
incidental taking of marine mammals. NMFS has reviewed the Navy's data 
and analysis and determined that it is complete and accurate and agrees 
that the following

[[Page 46364]]

stressors have the potential to result in takes by harassment of marine 
mammals from the Navy's planned activities.
    [ssquf] Acoustics (sonar and other transducers);
    [ssquf] Explosives (explosive shock wave and sound, assumed to 
encompass the risk due to fragmentation).
    The quantitative analysis process used for the 2020 MITT FSEIS/OEIS 
and the Navy's take request in the rulemaking/LOA application to 
estimate potential exposures to marine mammals resulting from acoustic 
and explosive stressors is detailed in the technical report titled 
Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods 
and Analytical Approach for Phase III Training and Testing (U.S. 
Department of the Navy, 2018). The Navy Acoustic Effects Model (NAEMO) 
brings together scenario simulations of the Navy's activities, sound 
propagation modeling, and marine mammal distribution (based on density 
and group size) by species to model and quantify the exposure of marine 
mammals above identified thresholds for behavioral harassment, TTS, 
PTS, non-auditory injury, and mortality.
    NAEMO estimates acoustic and explosive effects without taking 
mitigation into account; therefore, the model overestimates predicted 
impacts on marine mammals within mitigation zones. To account for 
mitigation for marine species in the take estimates, the Navy conducts 
a quantitative assessment of mitigation. The Navy conservatively 
quantifies the manner in which procedural mitigation is expected to 
reduce the risk for model-estimated PTS for exposures to sonars and for 
model-estimated mortality for exposures to explosives, based on species 
sightability, observation area, visibility, and the ability to exercise 
positive control over the sound source. See the proposed rule (85 FR 
5782; January 31, 2020) for a description of the process for assessing 
the effectiveness of procedural mitigation measures, along with the 
process for assessing the potential for animal avoidance. Where the 
analysis indicates mitigation would effectively reduce risk, the model-
estimated PTS takes are considered reduced to TTS and the model-
estimated mortalities are considered reduced to injury. For a complete 
explanation of the process for assessing the effects of procedural 
mitigation, see the Navy's rulemaking/LOA application (Section 6: Take 
Estimates for Marine Mammals, and Section 11: Mitigation Measures) and 
the technical report titled Quantifying Acoustic Impacts on Marine 
Mammals and Sea Turtles: Methods and Analytical Approach for Phase III 
Training and Testing (U.S. Department of the Navy, 2018). The extent to 
which the mitigation areas reduce impacts on the affected species is 
addressed qualitatively separately in the Analysis and Negligible 
Impact Determination section.
    NMFS coordinated with the Navy in the development of this 
quantitative method to address the effects of procedural mitigation on 
acoustic and explosive exposures and takes, and NMFS independently 
reviewed and concurs with the Navy that it is appropriate to 
incorporate the quantitative assessment of mitigation into the take 
estimates based on the best available science.
    As a general matter, NMFS does not prescribe the methods for 
estimating take for any applicant, but we review and ensure that 
applicants use the best available science, and methodologies that are 
logical and technically sound. Applicants may use different methods of 
calculating take (especially when using models) and still get to a 
result that is representative of the best available science and that 
allows for a rigorous and accurate evaluation of the effects on the 
affected populations. There are multiple pieces of the Navy take 
estimation methods--propagation models, animat movement models, and 
behavioral thresholds, for example. NMFS evaluates the acceptability of 
these pieces as they evolve and are used in different rules and impact 
analyses. Some of the pieces of the Navy's take estimation process have 
been used in Navy incidental take rules since 2009 and undergone 
multiple public comment processes, all of them have undergone extensive 
internal Navy review, and all of them have undergone comprehensive 
review by NMFS, which has sometimes resulted in modifications to 
methods or models.
    The Navy uses rigorous review processes (verification, validation, 
and accreditation processes, peer and public review) to ensure the data 
and methodology it uses represent the best available science. For 
instance, the NAEMO model is the result of a NMFS-led Center for 
Independent Experts (CIE) review of the components used in earlier 
models. The acoustic propagation component of the NAEMO model (CASS/
GRAB) is accredited by the Oceanographic and Atmospheric Master Library 
(OAML), and many of the environmental variables used in the NAEMO model 
come from approved OAML databases and are based on in-situ data 
collection. The animal density components of the NAEMO model are base 
products of the NMSDD, which includes animal density components that 
have been validated and reviewed by a variety of scientists from NMFS 
Science Centers and academic institutions. Several components of the 
model, for example the Duke University habitat-based density models, 
have been published in peer reviewed literature. Others like the 
Atlantic Marine Assessment Program for Protected Species, which was 
conducted by NMFS Science Centers, have undergone quality assurance and 
quality control (QA/QC) processes. Finally the NAEMO model simulation 
components underwent QA/QC review and validation for model parts such 
as the scenario builder, acoustic builder, scenario simulator, etc., 
conducted by qualified statisticians and modelers to ensure accuracy. 
Other models and methodologies have gone through similar review 
processes.
    In summary, we believe the Navy's methods, including the underlying 
NAEMO modeling and the method for incorporating mitigation and 
avoidance, are the most appropriate methods for predicting non-auditory 
injury, PTS, TTS, and behavioral disturbance. But even with the 
consideration of mitigation and avoidance, given some of the more 
conservative components of the methodology (e.g., the thresholds do not 
consider ear recovery between pulses), we would describe the 
application of these methods as identifying the maximum number of 
instances in which marine mammals would be reasonably expected to be 
taken through non-auditory injury, PTS, TTS, or behavioral disturbance.
Humpback Whales Around Saipan
    As noted above, since publication of the proposed rule, additional 
information and analysis have been used to refine the assessment for 
the impacts of sonar training and testing on humpback whales around 
Saipan, resulting in an increase in the total take numbers for humpback 
whales. Below, we present updated information describing both the 
Navy's activities and expected humpback whale occurrence in the 
specific area, as well as the additional analysis of this information 
to estimate take of humpback whales in this subset of the MITT Study 
Area. This information was then used to refine the total take numbers 
for humpback whales and the change is reflected in Table 28 and Table 
47.
    Given concern for impacts to humpback whales, including cow-calf 
pairs, in the Chalan Kanoa Reef and Marpi Reef Geographic Mitigation 
Areas, more specific information regarding Navy activities, and the

[[Page 46365]]

availability of more detailed occurrence data for humpback whales in 
these areas, and in coordination with NMFS' Interagency Cooperation 
Division, NMFS has updated and refined the analysis of humpback whale 
impacts in these areas since publication of the proposed rule. The 
analysis considers the new annual 20-hour cap on MF1 hull-mounted sonar 
in both mitigation areas and, specifically, estimates potential take of 
humpback whales should the Navy conduct the full 20 hours of sonar 
training and testing in these areas, most likely in the form of a Small 
Coordinated ASW Exercises or TRACKEX events (or a combination of these 
two activities).
    At the request of NMFS, subsequent to the publication of the 
proposed rule, the Navy provided refined estimates of the number of 
humpback whales estimated to be taken as prorated from the NAEMO model. 
These new estimates were based on 20 hours of MF1 MFAS occurring in the 
Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas (outside 
of 3 nmi and waters deeper than 60 m) during December through April. 
The analysis assumed takes could occur in either of the two geographic 
mitigation areas. The resulting take estimates provided by the Navy 
were 2.12 takes by behavioral disturbance and 11.08 takes by TTS (a 
total of 13.20 takes by Level B harassment). These take estimates 
represent five ASW TRACKEX events with each event using four hours of 
MF1 sonar. While other configurations of the 20 hours could occur, NMFS 
and the Navy concur that five 4-hour exercises on five different days 
best represents the likely scenario that allows for the most 
appropriate take estimate. A single 4-hr TRACKEX event was expected to 
result in 0.42 takes by behavioral disturbance and 2.2 takes by TTS (a 
total of 2.62 takes by Level B harassment). However, the approach used 
to calculate these take estimates did not adequately consider the 
concentration of humpback whales found within these established 
breeding and calving grounds from December through April.
    NMFS conducted its own analysis of the take by Level A harassment 
(by PTS) and Level B harassment (both TTS and behavioral disruption) 
that could occur in the Chalan Kanoa Reef and Marpi Reef Geographic 
Mitigation Areas under the 20-hr cap, for the purposes of both better 
understanding the impacts to adults and calves in this important area 
and modifying the total take numbers for humpback whales given more 
granular survey data now being considered in this area. Our exposure 
analysis is focused on the whales within the areas around Saipan 
covered by the surveys conducted by the PIFSC and reported in the Hill 
et al. (2020a) paper and the Hill et al. (2020b) abundance and density 
report. We believe this approach more accurately estimates potential 
exposures and takes of whales as a result of MF1 MFAS in these two 
Geographic Mitigation Areas. More extensive mark/recapture data in this 
smaller area provide a more granular and robust estimate of potential 
abundance and density for this specific area than the density estimate 
used by the Navy for the broader MITT Study Area. Estimates provided by 
the PIFSC (Hill et al., 2020b) are preliminary, represent ``snapshots'' 
of abundance for that survey period based on the timing of the survey, 
and may change--but these estimates represent the best available 
scientific data for two reasons: (1) Estimates are area specific; and 
(2) estimates are far more robust than a non-model approach (e.g., 
sightings per unit of effort approach).
    We used an approach based on the annual abundance estimates from 
the PIFSC report (Hill et al., 2020b) to derive estimates of animals 
that may be exposed to MF1 MFAS within these two Geographic Mitigation 
Areas. Preliminary annual (2015-2019) estimates of abundance, including 
standard errors (SE), 95 percent confidence intervals (CI), and 
densities of humpback whales in the PIFSC's study area were calculated 
using mark-recapture analyses (Table 3 in Hill et al., 2020b). 
Densities (whales/km\2\) are reported for the full survey area (839 
km\2\) and the truncated survey area where most of the effort and all 
of the humpback whale encounters occurred (384 km\2\) areas off the 
west side of Saipan to Chalan Kanoa Reef and north to Marpi Reef. The 
error associated with the average non-calf and total abundance was 
obtained by summing the variances of the annual estimates even though 
these estimates are not independent, as using a bootstrap or other 
approach to estimate uncertainty was beyond the scope of this 
preliminary analysis. The average non-calf abundance from 2015-2019 was 
44 animals (Table 3 in Hill et al., 2020b). PIFSC provided estimates of 
calf abundance in their annual abundance estimates by increasing the 
average annual abundance of whales (non-calf) by the proportion of 
calves seen in the four years of surveys where calves were seen (2015-
2018). The proportion of calves ranges from 0.5 to 0.2. This increased 
the average number of animals (non-calf) from 44 to 61 (total abundance 
(44) and 17 calves; with a 95 percent CI of 41-91) animals. Therefore, 
we are conservatively estimating that 61 animals a day could be taken 
on 5 days in which the exercise occurs for a total of 305 humpback 
whales taken by Level B harassment annually in the two Geographic 
Mitigation Areas combined (assuming 20 hrs of MF1 MFAS occurred). The 
Navy provided updated NAEMO-based calculations (as described above) 
that estimated 13 takes by Level B harassment during 20 hours of MF1 
sonar. Subtracting these 13 takes from our estimate of 305 exposures 
(takes) results in 292 animals based on the new abundance information. 
Using the proportions of these takes as presented by the Navy estimated 
take (12 percent behavioral and 88 percent TTS) results in an 
additional 35 takes by behavioral disturbance and 257 takes by TTS 
annually.
    This is a greater number of takes and a more conservative approach 
than the Navy's estimate and increases the total take by Level B 
harassment, but also provides a more accurate representation of how 
many takes by Level B harassment could occur during the breeding season 
in the two Geographic Mitigation Areas. The maximum number of animals 
(61) that could be taken in a day is a very conservative, worst-case 
scenario estimate based on the best available abundance data for 
humpback whales. We do not know how humpback whales move between the 
two Geographic Mitigation Areas or if more whales may be present in one 
Geographic Mitigation Area versus the other when the Navy is conducting 
their activity. We also assume the Navy could engage in exercises that 
only occur in one of two Geographic Mitigation Areas or it could be 
split between the two areas and involve multiple ships. We also 
acknowledge takes of humpback whales would certainly be less if the 
Navy's MF1 MFAS use occurs at the beginning or toward the end of the 
breeding season in the Geographic Mitigation Areas.
    There is a very low likelihood that a humpback whale would 
accumulate enough exposure to result in PTS in the two Geographic 
Mitigation Areas. However, the Navy's approach to accounting for 
avoidance does not address possible differences in avoidance capability 
based on an animal's life-stage or particular life function at the time 
of exposure. Mother-calf pairs on the calving grounds may be less 
capable of avoiding additional exposures at levels that could cause 
PTS, as compared to individual adult males or females without calves. 
The age of the calf may also be a factor in the avoidance capability of 
a mother-

[[Page 46366]]

calf pair (e.g., neonates may be particularly vulnerable). Mother-calf 
pairs may respond differently to MF1 MFAS at close range. Other 
potential stressors (e.g., presence of breeding males, other nearby 
vessel activity, or potential predators) may influence how humpback 
whales (including cow-calf pairs) respond to acoustic stressors. 
Therefore, we estimate that up to one mother-calf pair of humpback 
whales could be taken by Level A harassment by PTS over the total 
seven-year period of the rule.
    Additional mitigation by the Navy will include reporting of all 
active sonar use (all bins, by bin) in the Marpi Reef and Chalan Kanoa 
Geographic Mitigation Areas from December 1 through April 30. This will 
provide NMFS with more specific data in order to evaluate sonar use 
with current mitigation measures in the Geographic Mitigation Areas and 
to determine if any changes are needed through Adaptive Management.

Summary of Estimated Take From Training and Testing Activities

    Based on the methods discussed in the previous sections and the 
Navy's model and quantitative assessment of mitigation, the Navy 
provided its take estimate and request for authorization of takes 
incidental to the use of acoustic and explosive sources for training 
and testing activities both annually (based on the maximum number of 
activities that could occur per 12-month period) and over the seven-
year period covered by the Navy's rulemaking/LOA application. NMFS has 
reviewed the Navy's data, methodology, and analysis and determined that 
it is complete and accurate. NMFS agrees that the estimates for 
incidental takes by harassment from all sources requested for 
authorization are the maximum number of instances in which marine 
mammals are reasonably expected to be taken.
    For training and testing activities, Table 28 summarizes the Navy's 
take estimate and request and includes the maximum amount of Level A 
harassment and Level B harassment annually and for the seven-year 
period that NMFS concurs is reasonably likely to occur by species. Note 
that take by Level B harassment includes both behavioral disturbance 
and TTS. Tables 6.4-13 through 6.4-38 in Section 6 of the Navy's 
rulemaking/LOA application provide the comparative amounts of TTS and 
behavioral disturbance for each species annually, noting that if a 
modeled marine mammal was ``taken'' through exposure to both TTS and 
behavioral disruption in the model, it was recorded as a TTS.

  Table 28--Annual and Seven-Year Total Species-Specific Take Estimates Authorized From Acoustic and Explosive
               Sound Source Effects for All Training and Testing Activities in the MITT Study Area
----------------------------------------------------------------------------------------------------------------
                                                              Annual                     7-Year total \1\
                                                 ---------------------------------------------------------------
                     Species                          Level B         Level A         Level B         Level A
                                                    harassment      harassment      harassment      harassment
----------------------------------------------------------------------------------------------------------------
Mysticetes
    Blue whale *................................              24               0             169               0
    Bryde's whale...............................             298               0           2,078               0
    Fin whale *.................................              25               0             173               0
    Humpback whale *............................             771               0           3,348            ** 1
    Minke whale.................................              95               0             665               0
    Omura's whale...............................              29               0             199               0
    Sei whale*..................................             155               0           1,083               0
Odontocetes
    Blainville's beaked whale...................           1,718               0          12,033               0
    Bottlenose dolphin..........................             137               0             961               0
    Cuvier's beaked whale.......................             646               0           4,529               0
    Dwarf sperm whale...........................           8,499              50          59,459             341
    False killer whale..........................             762               0           5,331               0
    Fraser's dolphin............................          13,278               1          92,931               8
    Ginkgo-toothed beaked whale.................           3,726               0          26,088               0
    Killer whale................................              44               0             309               0
    Longman's beaked whale......................           6,066               0          42,487               0
    Melon-headed whale..........................           2,815               0          19,691               0
    Pantropical spotted dolphin.................          14,896               1         104,242               7
    Pygmy killer whale..........................             104               0             726               0
    Pygmy sperm whale...........................           3,410              19          23,853             136
    Risso's dolphin.............................           3,170               0          22,179               0
    Rough-toothed dolphin.......................             197               0           1,379               0
    Short-finned pilot whale....................           1,163               0           8,140               0
    Sperm whale *...............................             203               0           1,420               0
    Spinner dolphin.............................           1,414               1           9,896               4
    Striped dolphin.............................           4,007               0          28,038               0
----------------------------------------------------------------------------------------------------------------
* ESA-listed species within the MITT Study Area.
** There is one mother-calf pair of humpback whales estimated to be taken by Level A harassment by PTS over the
  period of the rule. See the Estimated Take of Marine Mammals section for further details.
\1\ The 7-year totals may be less than the annual totals times seven, given that not all activities occur every
  year, some activities occur multiple times within a year, and some activities only occur a few times over the
  course of a 7-year period.

Mitigation Measures

    Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the 
permissible methods of taking pursuant to the activity, and other means 
of effecting the least practicable adverse impact on the species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of the species or stocks for subsistence uses (``least 
practicable

[[Page 46367]]

adverse impact''). NMFS does not have a regulatory definition for least 
practicable adverse impact. The 2004 NDAA amended the MMPA as it 
relates to military readiness activities and the incidental take 
authorization process such that a determination of ``least practicable 
adverse impact'' shall include consideration of personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
military readiness activity.
    In Conservation Council for Hawaii v. National Marine Fisheries 
Service, 97 F. Supp.3d 1210, 1229 (D. Haw. 2015), the Court stated that 
NMFS ``appear[s] to think [it] satisf[ies] the statutory `least 
practicable adverse impact' requirement with a `negligible impact' 
finding.'' More recently, expressing similar concerns in a challenge to 
a U.S. Navy Surveillance Towed Array Sensor System Low Frequency Active 
Sonar (SURTASS LFA) incidental take rule (77 FR 50290), the Ninth 
Circuit Court of Appeals in Natural Resources Defense Council (NRDC) v. 
Pritzker, 828 F.3d 1125, 1134 (9th Cir. 2016), stated, ``[c]ompliance 
with the `negligible impact' requirement does not mean there [is] 
compliance with the `least practicable adverse impact' standard.'' As 
the Ninth Circuit noted in its opinion, however, the Court was 
interpreting the statute without the benefit of NMFS' formal 
interpretation. We state here explicitly that NMFS is in full agreement 
that the ``negligible impact'' and ``least practicable adverse impact'' 
requirements are distinct, even though both statutory standards refer 
to species and stocks. With that in mind, we provide further 
explanation of our interpretation of least practicable adverse impact, 
and explain what distinguishes it from the negligible impact standard. 
This discussion is consistent with previous rules we have issued, such 
as the Navy's HSTT rule (83 FR 66846; December 27, 2018), Atlantic 
Fleet Training and Testing rule (84 FR 70712; December 23, 2019), and 
the Northwest Training and Testing (NWTT) proposed rule (0648-BJ30; 
June 02, 2020).
    Before NMFS can issue incidental take regulations under section 
101(a)(5)(A) of the MMPA, it must make a finding that the total taking 
will have a ``negligible impact'' on the affected ``species or stocks'' 
of marine mammals. NMFS' and U.S. Fish and Wildlife Service's 
implementing regulations for section 101(a)(5) both define ``negligible 
impact'' 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 (50 CFR 216.103 and 50 CFR 18.27(c)). 
Recruitment (i.e., reproduction) and survival rates are used to 
determine population growth rates \2\ and therefore are considered in 
evaluating population level impacts.
---------------------------------------------------------------------------

    \2\ A growth rate can be positive, negative, or flat.
---------------------------------------------------------------------------

    As stated in the preamble to the proposed rule for the MMPA 
incidental take implementing regulations, not every population-level 
impact violates the negligible impact requirement. 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. The key factor is the significance of 
the level of impact on rates of recruitment or survival. (54 FR 40338, 
40341-42; September 29, 1989).
    While some level of impact on population numbers or growth rates of 
a species or stock may occur and still satisfy the negligible impact 
requirement--even without consideration of mitigation--the least 
practicable adverse impact provision separately requires NMFS to 
prescribe means of effecting the least practicable adverse impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, 50 CFR 
216.102(b), which are typically identified as mitigation measures.\3\
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    \3\ For purposes of this discussion, we omit reference to the 
language in the standard for least practicable adverse impact that 
says we also must mitigate for subsistence impacts because they are 
not at issue in this rule.
---------------------------------------------------------------------------

    The negligible impact and least practicable adverse impact 
standards in the MMPA both call for evaluation at the level of the 
``species or stock.'' The MMPA does not define the term ``species.'' 
However, Merriam-Webster Dictionary defines ``species'' to include 
``related organisms or populations potentially capable of 
interbreeding.'' See www.merriam-webster.com/dictionary/species 
(emphasis added). Section 3(11) of the MMPA defines ``stock'' as a 
group of marine mammals of the same species or smaller taxa in a common 
spatial arrangement that interbreed when mature. The definition of 
``population'' is a group of interbreeding organisms that represents 
the level of organization at which speciation begins. www.merriam-webster.com/dictionary/population. The definition of ``population'' is 
strikingly similar to the MMPA's definition of ``stock,'' with both 
definitions involving groups of individuals that belong to the same 
species and that are located in a manner that allows for interbreeding. 
In fact under MMPA section 3(11), the term ``stock'' in the MMPA is 
interchangeable with the statutory term ``population stock.'' Both the 
negligible impact standard and the least practicable adverse impact 
standard call for evaluation at the level of the species or stock, and 
the terms ``species'' and ``stock'' both relate to populations; 
therefore, it is appropriate to view both the negligible impact 
standard and the least practicable adverse impact standard as having a 
population-level focus.
    This interpretation is consistent with Congress' statutory findings 
for enacting the MMPA, nearly all of which are most applicable at the 
species or stock (i.e., population) level. See MMPA section 2 (finding 
that it is species and population stocks that are or may be in danger 
of extinction or depletion; that it is species and population stocks 
that should not diminish beyond being significant functioning elements 
of their ecosystems; and that it is species and population stocks that 
should not be permitted to diminish below their optimum sustainable 
population level). Annual rates of recruitment (i.e., reproduction) and 
survival are the key biological metrics used in the evaluation of 
population-level impacts, and accordingly these same metrics are also 
used in the evaluation of population level impacts for the least 
practicable adverse impact standard.
    Recognizing this common focus of the least practicable adverse 
impact and negligible impact provisions on the ``species or stock'' 
does not mean we conflate the two standards; despite some common 
statutory language, we recognize the two provisions are different and 
have different functions. First, a negligible impact finding is 
required before NMFS can issue an incidental take authorization. 
Although it is acceptable to use the mitigation measures to reach a 
negligible impact finding (see 50 CFR 216.104(c)), no amount of 
mitigation can enable NMFS to issue an incidental take authorization 
for an activity that still would not meet the negligible impact 
standard. Moreover, even where NMFS can reach a negligible impact 
finding--which we emphasize does allow for the possibility of some 
``negligible'' population-level impact--the agency must still prescribe 
measures that will effect the least practicable amount of adverse 
impact upon the affected species or stock.
    Section 101(a)(5)(A)(i)(II) requires NMFS to issue, in conjunction 
with its authorization, binding--and

[[Page 46368]]

enforceable--restrictions (in the form of regulations) setting forth 
how the activity must be conducted, thus ensuring the activity has the 
``least practicable adverse impact'' on the affected species or stocks. 
In situations where mitigation is specifically needed to reach a 
negligible impact determination, section 101(a)(5)(A)(i)(II) also 
provides a mechanism for ensuring compliance with the ``negligible 
impact'' requirement. Finally, the least practicable adverse impact 
standard also requires consideration of measures for marine mammal 
habitat, with particular attention to rookeries, mating grounds, and 
other areas of similar significance, and for subsistence impacts, 
whereas the negligible impact standard is concerned solely with 
conclusions about the impact of an activity on annual rates of 
recruitment and survival.\4\ In NRDC v. Pritzker, the Court stated, 
``[t]he statute is properly read to mean that even if population levels 
are not threatened significantly, still the agency must adopt 
mitigation measures aimed at protecting marine mammals to the greatest 
extent practicable in light of military readiness needs.'' Pritzker at 
1134 (emphases added). This statement is consistent with our 
understanding stated above that even when the effects of an action 
satisfy the negligible impact standard (i.e., in the Court's words, 
``population levels are not threatened significantly''), still the 
agency must prescribe mitigation under the least practicable adverse 
impact standard. However, as the statute indicates, the focus of both 
standards is ultimately the impact on the affected ``species or 
stock,'' and not solely focused on or directed at the impact on 
individual marine mammals.
---------------------------------------------------------------------------

    \4\ Outside of the military readiness context, mitigation may 
also be appropriate to ensure compliance with the ``small numbers'' 
language in MMPA sections 101(a)(5)(A) and (D).
---------------------------------------------------------------------------

    We have carefully reviewed and considered the Ninth Circuit's 
opinion in NRDC v. Pritzker in its entirety. While the Court's 
reference to ``marine mammals'' rather than ``marine mammal species or 
stocks'' in the italicized language above might be construed as a 
holding that the least practicable adverse impact standard applies at 
the individual ``marine mammal'' level, i.e., that NMFS must require 
mitigation to minimize impacts to each individual marine mammal unless 
impracticable, we believe such an interpretation reflects an incomplete 
appreciation of the Court's holding. In our view, the opinion as a 
whole turned on the Court's determination that NMFS had not given 
separate and independent meaning to the least practicable adverse 
impact standard apart from the negligible impact standard, and further, 
that the Court's use of the term ``marine mammals'' was not addressing 
the question of whether the standard applies to individual animals as 
opposed to the species or stock as a whole. We recognize that while 
consideration of mitigation can play a role in a negligible impact 
determination, consideration of mitigation measures extends beyond that 
analysis. In evaluating what mitigation measures are appropriate, NMFS 
considers the potential impacts of the Specified Activities, the 
availability of measures to minimize those potential impacts, and the 
practicability of implementing those measures, as we describe below.

Implementation of Least Practicable Adverse Impact Standard

    Given the NRDC v. Pritzker decision, we discuss here how we 
determine whether a measure or set of measures meets the ``least 
practicable adverse impact'' standard. Our separate analysis of whether 
the take anticipated to result from the Navy's activities meets the 
``negligible impact'' standard appears in the Analysis and Negligible 
Impact Determination section below.
    Our evaluation of potential mitigation measures includes 
consideration of two primary factors:
    (1) The manner in which, and the degree to which, implementation of 
the potential measure(s) is expected to reduce adverse impacts to 
marine mammal species or stocks, their habitat, and their availability 
for subsistence uses (where relevant). This analysis considers such 
things as the nature of the potential adverse impact (such as 
likelihood, scope, and range), the likelihood that the measure will be 
effective if implemented, and the likelihood of successful 
implementation; and
    (2) The practicability of the measures for applicant 
implementation. Practicability of implementation may consider such 
things as cost, impact on activities, and, in the case of a military 
readiness activity, specifically considers personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
military readiness activity.
    While the language of the least practicable adverse impact standard 
calls for minimizing impacts to affected species or stocks, we 
recognize that the reduction of impacts to those species or stocks 
accrues through the application of mitigation measures that limit 
impacts to individual animals. Accordingly, NMFS' analysis focuses on 
measures that are designed to avoid or minimize impacts on individual 
marine mammals that are likely to increase the probability or severity 
of population-level effects.
    While direct evidence of impacts to species or stocks from a 
specified activity is rarely available, and additional study is still 
needed to understand how specific disturbance events affect the fitness 
of individuals of certain species, there have been improvements in 
understanding the process by which disturbance effects are translated 
to the population. With recent scientific advancements (both marine 
mammal energetic research and the development of energetic frameworks), 
the relative likelihood or degree of impacts on species or stocks may 
often be inferred given a detailed understanding of the activity, the 
environment, and the affected species or stocks--and the best available 
science has been used here. This same information is used in the 
development of mitigation measures and helps us understand how 
mitigation measures contribute to lessening effects (or the risk 
thereof) to species or stocks. We also acknowledge that there is always 
the potential that new information, or a new recommendation could 
become available in the future and necessitate reevaluation of 
mitigation measures (which may be addressed through adaptive 
management) to see if further reductions of population impacts are 
possible and practicable.
    In the evaluation of specific measures, the details of the 
specified activity will necessarily inform each of the two primary 
factors discussed above (expected reduction of impacts and 
practicability), and are carefully considered to determine the types of 
mitigation that are appropriate under the least practicable adverse 
impact standard. Analysis of how a potential mitigation measure may 
reduce adverse impacts on a marine mammal stock or species, 
consideration of personnel safety, practicality of implementation, and 
consideration of the impact on effectiveness of military readiness 
activities are not issues that can be meaningfully evaluated through a 
yes/no lens. The manner in which, and the degree to which, 
implementation of a measure is expected to reduce impacts, as well as 
its practicability in terms of these considerations, can vary widely. 
For example, a time/area restriction could be of very high value for 
decreasing population-level impacts (e.g., avoiding disturbance of 
feeding females in an area of established biological importance) or it 
could be of

[[Page 46369]]

lower value (e.g., decreased disturbance in an area of high 
productivity but of less biological importance). Regarding 
practicability, a measure might involve restrictions in an area or time 
that impedes the Navy's ability to certify a strike group (higher 
impact on mission effectiveness and national security), or it could 
mean delaying a small in-port training event by 30 minutes to avoid 
exposure of a marine mammal to injurious levels of sound (lower 
impact). A responsible evaluation of ``least practicable adverse 
impact'' will consider the factors along these realistic scales. 
Accordingly, the greater the likelihood that a measure will contribute 
to reducing the probability or severity of adverse impacts to the 
species or stock or its habitat, the greater the weight that measure is 
given when considered in combination with practicability to determine 
the appropriateness of the mitigation measure, and vice versa. We 
discuss consideration of these factors in greater detail below.
    1. Reduction of adverse impacts to marine mammal species or stocks 
and their habitat.\5\ The emphasis given to a measure's ability to 
reduce the impacts on a species or stock considers the degree, 
likelihood, and context of the anticipated reduction of impacts to 
individuals (and how many individuals) as well as the status of the 
species or stock.
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    \5\ We recognize the least practicable adverse impact standard 
requires consideration of measures that will address minimizing 
impacts on the availability of the species or stocks for subsistence 
uses where relevant. Because subsistence uses are not implicated for 
this action, we do not discuss them. However, a similar framework 
would apply for evaluating those measures, taking into account the 
MMPA's directive that we make a finding of no unmitigable adverse 
impact on the availability of the species or stocks for taking for 
subsistence, and the relevant implementing regulations.
---------------------------------------------------------------------------

    The ultimate impact on any individual from a disturbance event 
(which informs the likelihood of adverse species- or stock-level 
effects) is dependent on the circumstances and associated contextual 
factors, such as duration of exposure to stressors. Though any proposed 
mitigation needs to be evaluated in the context of the specific 
activity and the species or stocks affected, measures with the 
following types of effects have greater value in reducing the 
likelihood or severity of adverse species- or stock-level impacts: 
Avoiding or minimizing injury or mortality; limiting interruption of 
known feeding, breeding, mother/young, or resting behaviors; minimizing 
the abandonment of important habitat (temporally and spatially); 
minimizing the number of individuals subjected to these types of 
disruptions; and limiting degradation of habitat. Mitigating these 
types of effects is intended to reduce the likelihood that the activity 
will result in energetic or other types of impacts that are more likely 
to result in reduced reproductive success or survivorship. It is also 
important to consider the degree of impacts that are expected in the 
absence of mitigation in order to assess the added value of any 
potential measures. Finally, because the least practicable adverse 
impact standard gives NMFS discretion to weigh a variety of factors 
when determining appropriate mitigation measures and because the focus 
of the standard is on reducing impacts at the species or stock level, 
the least practicable adverse impact standard does not compel 
mitigation for every kind of take, or every individual taken, if that 
mitigation is unlikely to meaningfully contribute to the reduction of 
adverse impacts on the species or stock and its habitat, even when 
practicable for implementation by the applicant.
    The status of the species or stock is also relevant in evaluating 
the appropriateness of potential mitigation measures in the context of 
least practicable adverse impact. The following are examples of factors 
that may (either alone, or in combination) result in greater emphasis 
on the importance of a mitigation measure in reducing impacts on a 
species or stock: The stock is known to be decreasing or status is 
unknown, but believed to be declining; the known annual mortality (from 
any source) is approaching or exceeding the potential biological 
removal (PBR) level (as defined in MMPA section 3(20)); the affected 
species or stock is a small, resident population; or the stock is 
involved in a UME or has other known vulnerabilities, such as 
recovering from an oil spill.
    Habitat mitigation, particularly as it relates to rookeries, mating 
grounds, and areas of similar significance, is also relevant to 
achieving the standard and can include measures such as reducing 
impacts of the activity on known prey utilized in the activity area or 
reducing impacts on physical habitat. As with species- or stock-related 
mitigation, the emphasis given to a measure's ability to reduce impacts 
on a species or stock's habitat considers the degree, likelihood, and 
context of the anticipated reduction of impacts to habitat. Because 
habitat value is informed by marine mammal presence and use, in some 
cases there may be overlap in measures for the species or stock and for 
use of habitat.
    We consider available information indicating the likelihood of any 
measure to accomplish its objective. If evidence shows that a measure 
has not typically been effective nor successful, then either that 
measure should be modified or the potential value of the measure to 
reduce effects should be lowered.
    2. Practicability. Factors considered may include cost, impact on 
activities, and, in the case of a military readiness activity, will 
include personnel safety, practicality of implementation, and impact on 
the effectiveness of the military readiness activity (see MMPA section 
101(a)(5)(A)(ii)).

Assessment of Mitigation Measures for the MITT Study Area

    Section 216.104(a)(11) of NMFS' implementing regulations requires 
an applicant for incidental take authorization to include in its 
request, among other things, ``the availability and feasibility 
(economic and technological) of equipment, methods, and manner of 
conducting such activity or other means of effecting the least 
practicable adverse impact upon the affected species or stocks, their 
habitat, and [where applicable] on their availability for subsistence 
uses, paying particular attention to rookeries, mating grounds, and 
areas of similar significance.'' Thus NMFS' analysis of the sufficiency 
and appropriateness of an applicant's measures under the least 
practicable adverse impact standard will always begin with evaluation 
of the mitigation measures presented in the application.
    NMFS has fully reviewed the specified activities and the mitigation 
measures included in the Navy's rulemaking/LOA application and the 2020 
MITT FSEIS/OEIS to determine if the mitigation measures would result in 
the least practicable adverse impact on marine mammals and their 
habitat. NMFS worked with the Navy in the development of the Navy's 
initially proposed measures, which were informed by years of 
implementation and monitoring. A complete discussion of the Navy's 
evaluation process used to develop, assess, and select mitigation 
measures, which was informed by input from NMFS, can be found in 
Section 5 (Mitigation) and Appendix I (Geographic Mitigation 
Assessment) of the 2020 MITT FSEIS/OEIS. The process described in 
Section 5 (Mitigation) and Appendix I (Geographic Mitigation 
Assessment) of the 2020 MITT FSEIS/OEIS robustly supported NMFS' 
independent evaluation of whether the mitigation measures meet the 
least practicable adverse impact standard.
    As a general matter, where an applicant proposes measures that are 
likely to reduce impacts to marine

[[Page 46370]]

mammals, the fact that they are included in the application indicates 
that the measures are practicable, and it is not necessary for NMFS to 
conduct a detailed analysis of the measures the applicant proposed 
(rather, they are simply included). We note that in their application, 
the Navy added three geographic mitigation areas with accompanying 
mitigation measures that are new since the 2015-2020 MITT incidental 
take regulations: (1) Marpi Reef Geographic Mitigation Area--to avoid 
potential impacts from explosives on marine mammals and report hours of 
MFAS-MF1 within the mitigation area, which contains a seasonal presence 
of humpback whales (2) Chalan Kanoa Reef Geographic Mitigation Area--to 
avoid potential impacts from explosives on marine mammals and report 
hours of MFAS-MF1 within the mitigation area, which contains a seasonal 
presence of humpback whales, and (3) Agat Bay Nearshore Geographic 
Mitigation Area--to avoid potential impacts from explosives and MFAS-
MF1 on spinner dolphins.
    However, it is still necessary for NMFS to consider whether there 
are additional practicable measures that would meaningfully reduce the 
probability or severity of impacts that could affect reproductive 
success or survivorship. In the case of this rule, we worked with the 
Navy after it submitted its 2019 rulemaking/LOA application but prior 
to the development of the proposed rule to expand the mitigation areas 
for Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas to 
more fully encompass the 400-m isobaths based on the available data 
indicating the presence of humpback whale mother/calf pairs (seasonal 
breeding area), which is expected to further avoid impacts from 
explosives that would be more likely to affect reproduction or survival 
of individuals and could adversely impact the species. The Navy will 
also implement the Marpi Reef and Chalan Kanoa Reef Awareness 
Notification Message Area, which require Navy personnel to broadcast 
the seasonal presence of humpback whales, further minimizing any 
potential impacts from vessel strikes during training and testing 
activities as these areas contain important seasonal breeding habitat 
for this species.
    In addition, since publication of the proposed rule, and in 
consideration of public comments received, NMFS and the Navy have 
agreed to include additional mitigation requirements that will further 
reduce the likelihood and/or severity of adverse impacts on marine 
mammal species and their habitat and are practicable for 
implementation. Below we describe the added measures that the Navy will 
implement and explain the manner in which they are expected to reduce 
the likelihood or severity of adverse impacts on humpback whales and 
their habitat.
    1. Cap on MF1 mid-frequency active sonar use in the Chalan Kanoa 
and Marpi Reef Geographic Mitigation Areas. The Navy will implement an 
annual 20-hour cap from December 1 through April 30 on surface ship 
hull-mounted MF1 mid-frequency active sonar within the Chalan Kanoa 
Reef and Marpi Reef Geographic Mitigation Areas to reduce impacts to 
humpback whales while allowing the Navy to retain critical shallow 
water training flexibility within the MITT Study Area. This cap on 
activities (MF1 sonar) in these areas with higher concentrations of 
humpback whales engaged in important reproductive behaviors is expected 
to reduce the probability or severity of impacts on humpback whales 
that would be more likely to adversely affect the reproduction or 
survival of any individual, which in turn reduces the likelihood that 
any impacts would translate to adverse impacts on the species.
    2. Additional reporting of sonar sources in the Chalan Kanoa and 
Marpi Reef Geographic Mitigation Areas. In addition to the reporting of 
the total hours of surface ship hull-mounted MF1 mid-frequency active 
sonar, the Navy will also report all sonar sources used (all bins, by 
bin) within the Chalan Kanoa and Marpi Reef Geographic Mitigation Areas 
from December 1 to April 30 in the annual MITT classified Exercise 
Reports. This will allow NMFS to evaluate sonar use specifically in 
these areas with higher concentrations of humpback whales and determine 
if further mitigation is needed through Adaptive Management.
    Overall the Navy has agreed to procedural mitigation measures that 
will reduce the probability and/or severity of impacts expected to 
result from acute exposure to acoustic sources and explosives, ship 
strike, and impacts to marine mammal habitat. Specifically, the Navy 
will use a combination of delayed starts, powerdowns, and shutdowns to 
avoid mortality or serious injury, minimize the likelihood or severity 
of PTS or other injury, and reduce instances of TTS or more severe 
behavioral disruption caused by acoustic sources or explosives. The 
Navy will also implement multiple time/area restrictions that will 
reduce take of marine mammals in areas or at times where they are known 
to engage in important behaviors, such as calving, where the disruption 
of those behaviors would have a higher probability of resulting in 
impacts on reproduction or survival of individuals that could lead to 
population-level impacts.
    The Navy assessed the practicability of these measures in the 
context of personnel safety, practicality of implementation, and their 
impacts on the Navy's ability to meet their Title 10 requirements and 
found that the measures are supportable. As described in more detail 
below, NMFS has independently evaluated the measures the Navy proposed 
in the manner described earlier in this section (i.e., in consideration 
of their ability to reduce adverse impacts on marine mammal species and 
their habitat and their practicability for implementation). We have 
determined that the measures will significantly and adequately reduce 
impacts on the affected marine mammal species and their habitat and, 
further, be practicable for Navy implementation. Therefore, the 
mitigation measures assure that Navy's activities will have the least 
practicable adverse impact on the species and their habitat.

Measures Evaluated But Not Included

    The Navy also evaluated numerous measures in the 2020 MITT FSEIS/
OEIS that were not included in the Navy's rulemaking/LOA application, 
and NMFS independently reviewed and concurs with the Navy's analysis 
that their inclusion was not appropriate under the least practicable 
adverse impact standard based on our assessment. The Navy considered 
these additional potential mitigation measures in two groups. First, 
Section 5 (Mitigation) of the 2020 MITT FSEIS/OEIS, in the Measures 
Considered but Eliminated section, includes an analysis of an array of 
different types of mitigation that have been recommended over the years 
by non-governmental organizations or the public, through scoping or 
public comment on environmental compliance documents. Appendix I 
(Geographic Mitigation Assessment) of the 2020 MITT FSEIS/OEIS includes 
an in-depth analysis of time/area restrictions that have been 
recommended over time. As described in Section 5 (Mitigation) of the 
2020 MITT FSEIS/OEIS, commenters sometimes recommend that the Navy 
reduce its overall amount of training and testing, reduce explosive 
use, modify its sound sources, completely replace live training and 
testing with computer simulation, or include time of day restrictions. 
Many of these mitigation measures could potentially reduce the number 
of marine mammals taken, via direct reduction of the

[[Page 46371]]

activities or amount of sound energy put in the water. However, as 
described in Section 5 (Mitigation) of the 2020 MITT FSEIS/OEIS, the 
Navy needs to train and test in the conditions in which it fights--and 
these types of modifications fundamentally change the activity in a 
manner that will not support the purpose and need for the training and 
testing (i.e., are entirely impracticable) and therefore are not 
considered further. NMFS finds the Navy's explanation for why adoption 
of these recommendations will unacceptably undermine the purpose of the 
testing and training persuasive. After independent review, NMFS finds 
Navy's judgment on the impacts of these potential mitigation measures 
to personnel safety, practicality of implementation, and the 
effectiveness of training and testing within the MITT Study Area 
persuasive, and for these reasons, NMFS finds that these measures do 
not meet the least practicable adverse impact standard because they are 
not practicable.
    Second, in Section 5 (Mitigation) of the 2020 MITT FSEIS/OEIS, the 
Navy evaluated additional potential procedural mitigation measures, 
including increased mitigation zones, ramp-up measures, additional 
passive acoustic and visual monitoring, and decreased vessel speeds. 
Some of these measures have the potential to incrementally reduce take 
to some degree in certain circumstances, though the degree to which 
this would occur is typically low or uncertain. However, as described 
in the Navy's analysis, the measures would have significant direct 
negative effects on mission effectiveness and are impracticable (see 
Section 5 Mitigation of 2020 MITT FSEIS/OEIS). NMFS independently 
reviewed the Navy's evaluation and concurs with this assessment, which 
supports NMFS' findings that the impracticability of this additional 
mitigation would greatly outweigh any potential minor reduction in 
marine mammal impacts that might result; therefore, these additional 
mitigation measures are not warranted.
    Last, Appendix I (Geographic Mitigation Assessment) of the 2020 
MITT FSEIS/OEIS describes a comprehensive method for analyzing 
potential geographic mitigation that includes consideration of both a 
biological assessment of how the potential time/area limitation would 
benefit the species and its habitat (e.g., is a key area of biological 
importance or would result in avoidance or reduction of impacts) in the 
context of the stressors of concern in the specific area and an 
operational assessment of the practicability of implementation 
(including an assessment of the specific importance of that area for 
training, considering proximity to training ranges and emergency 
landing fields and other issues). For most of the areas that were 
considered in the 2020 MITT FSEIS/OEIS but not included as mitigation 
in this rule, the Navy found that the mitigation was not warranted 
because the anticipated reduction of adverse impacts on marine mammal 
species and their habitat was not sufficient to offset the 
impracticability of implementation. In some cases, potential benefits 
to marine mammals were non-existent, while in others the consequences 
on mission effectiveness were too great.
    NMFS has reviewed the analysis in Section 5 (Mitigation) and 
Appendix I (Geographic Mitigation Assessment) of the 2020 MITT FSEIS/
OEIS, which considers the same factors that NMFS considers under the 
MMPA to satisfy the least practicable adverse impact standard, and 
concurs with the analysis and conclusions. Therefore, NMFS is not 
including any of the measures that the Navy ruled out in the 2020 MITT 
FSEIS/OEIS.
    Below, we describe additional measures that were considered but 
eliminated during the development of the final rule: (1) A full 
restriction on MF1 sonar use in the Marpi Reef and Chalan Kanoa Reef 
Geographic Mitigation Areas (versus the 20-hour annual cap between 
December 1 and April 30) and (2) measures to further minimize any 
potential risk that beaked whales would strand as a result of Navy 
training and testing activities.
    Regarding the consideration of a full restriction on MF1 sonar use 
in the Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas, 
areas of shallow depths, which are important for certain types of 
training, are limited in the Mariana Archipelago, and the Navy 
determined it would be impractical to completely limit the use of sonar 
at Chalan Kanoa Reef and Marpi Reef. The Navy provided additional 
analysis to NMFS that these two Geographic Mitigation Areas account for 
up to 14.3 percent of all shallow water areas less than 200 m and 
outside of 3 nmi in the MITT Study Area (generally surrounding land), 
and up to 22 percent of all shallow water areas less than 200 m and 
outside of 3 nmi (generally surrounding land) and south (not inclusive) 
of Farallon De Medinilla in the MITT Study Area. NMFS agreed with these 
calculations. The Navy has stressed the broader need for flexibility as 
well as the specific need not to restrict training areas entirely in 
this part of the MITT Study Area given the proximity to forward 
deployed operations (i.e., U.S. 7th fleet's continuous presence in the 
Indo-Pacific region, which is a National Defense Strategy priority 
theater of operations) and the need to have the option to conduct 
training quickly and to respond to emergent national security threats. 
Given the reductions in potential impacts already provided by the full 
restriction on explosive use and the 20-hour annual cap on MF1 sonar in 
the areas between December 1 and April 30, combined with the 
impracticability for the Navy, NMFS found that this measure was not 
warranted.
    In addition, NMFS had thorough discussions with the Navy about the 
possibility of crafting a mitigation measure to minimize the potential 
risk that Navy activities could contribute in any way to the potential 
stranding of beaked whales. These discussions included consideration of 
all public comments which recommended beaked whale mitigation measures. 
However, despite years of field surveys conducted under interagency 
agreements between the Navy and NMFS' PIFSC along with Navy-funded 
beaked whale monitoring, there remains a lack of scientific information 
available on beaked whale distribution and other essential species 
information in the Mariana Islands. Without sufficient scientific data 
on beaked whale habitat use, bathymetry, and seasonality, and from that 
a better understanding of the circumstances that could affect the 
likelihood of a stranding in the MITT Study Area, NMFS is unable to 
develop mitigation measures that would meaningfully reduce the 
likelihood of stranding and/or will not result in unreasonable 
operational/practicability concerns. Consequently, NMFS recommended to 
the Navy that the two agencies convene a panel of experts, both from 
the region, as well as beaked whale behavioral response experts from 
other geographic areas, and Navy experts on biology, operations, and 
mitigation to review the status of the science, identify data gaps, and 
identify information applicable for consideration for future mitigation 
through the Adaptive Management process. The Navy has agreed to fund 
and co-organize this effort. Additional measures that the Navy has 
agreed to conduct to increase understanding and decrease uncertainty 
around beaked whales in the MITT Study Area are discussed in the 
Monitoring section.
    The following sections describe the mitigation measures that will 
be implemented in association with the training and testing activities 
analyzed in this document. These are the mitigation measures that NMFS 
has determined will ensure the least

[[Page 46372]]

practicable adverse impact on all affected species and their habitat, 
including the specific considerations for military readiness 
activities. The mitigation measures are organized into two categories: 
Procedural mitigation and mitigation areas.

Procedural Mitigation

    Procedural mitigation is mitigation that the Navy will implement 
whenever and wherever an applicable training or testing activity takes 
place within the MITT Study Area. The Navy customizes procedural 
mitigation for each applicable activity category or stressor. 
Procedural mitigation generally involves: (1) The use of one or more 
trained Lookouts to diligently observe for specific biological 
resources (including marine mammals) within a mitigation zone, (2) 
requirements for Lookouts to immediately communicate sightings of 
specific biological resources to the appropriate watch station for 
information dissemination, and (3) requirements for the watch station 
to implement mitigation (e.g., halt an activity) until certain 
recommencement conditions have been met. The first procedural 
mitigation measures (Table 29) are designed to train Lookouts and other 
applicable Navy personnel in their observation, environmental 
compliance, and reporting responsibilities. The remainder of the 
procedural mitigation measures (Tables 30 through 46) are organized by 
stressor type and activity category and includes acoustic stressors 
(i.e., active sonar, weapons firing noise), explosive stressors (i.e., 
sonobuoys, torpedoes, medium-caliber and large-caliber projectiles, 
missiles and rockets, bombs, sinking exercises, mines, anti-swimmer 
grenades), and physical disturbance and strike stressors (i.e., vessel 
movement; towed in-water devices; small-, medium-, and large-caliber 
non-explosive practice munitions; non-explosive missiles and rockets, 
non-explosive bombs and mine shapes). Note that the procedural 
mitigation measures for other incidental take regulations in Navy study 
areas, such as AFTT and HSTT, require that Lookouts observe for 
floating vegetation in addition to marine mammals because floating 
vegetation has high ecological protection value (e.g., habitat for 
juvenile/hatchling sea turtles, potential foraging habitat for marine 
mammals). The term ``floating vegetation'' in those regulations 
referred specifically to floating concentrations of detached kelp 
paddies (off the U.S. West Coast) and sargassum mats (off the U.S. East 
Coast). However, in the MITT Study Area there are no floating 
vegetation concentrations so that was not included in the procedural 
mitigation measures in this rule.

     Table 29--Procedural Mitigation for Environmental Awareness and
                                Education
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
    All training and testing activities, as applicable.
Mitigation Requirements:
    Appropriate Navy personnel (including civilian personnel) involved
     in mitigation and training or testing activity reporting under the
     specified activities will complete one or more modules of the U.S.
     Navy Afloat Environmental Compliance Training Series, as identified
     in their career path training plan. Modules include:
        --Introduction to the U.S. Navy Afloat Environmental Compliance
         Training Series. The introductory module provides information
         on environmental laws (e.g., Endangered Species Act, Marine
         Mammal Protection Act) and the corresponding responsibilities
         that are relevant to Navy training and testing activities. The
         material explains why environmental compliance is important in
         supporting the Navy's commitment to environmental stewardship.
        --Marine Species Awareness Training. All bridge watch personnel,
         Commanding Officers, Executive Officers, maritime patrol
         aircraft aircrews, anti[hyphen]submarine warfare and mine
         warfare rotary-wing aircrews, Lookouts, and equivalent civilian
         personnel must successfully complete the Marine Species
         Awareness Training prior to standing watch or serving as a
         Lookout. The Marine Species Awareness Training provides
         information on sighting cues, visual observation tools and
         techniques, and sighting notification procedures. Navy
         biologists developed Marine Species Awareness Training to
         improve the effectiveness of visual observations for biological
         resources, focusing on marine mammals and sea turtles, and
         including floating vegetation, jellyfish aggregations, and
         flocks of seabirds.
        --U.S. Navy Protective Measures Assessment Protocol. This module
         provides the necessary instruction for accessing mitigation
         requirements during the event planning phase using the
         Protective Measures Assessment Protocol software tool.
        --U.S. Navy Sonar Positional Reporting System and Marine Mammal
         Incident Reporting. This module provides instruction on the
         procedures and activity reporting requirements for the Sonar
         Positional Reporting System and marine mammal incident
         reporting.
------------------------------------------------------------------------


            Table 30--Procedural Mitigation for Active Sonar
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Low-frequency active sonar, mid-frequency active sonar,
     high-frequency active sonar:
        --For vessel-based active sonar activities, mitigation applies
         only to sources that are positively controlled and deployed
         from manned surface vessels (e.g., sonar sources towed from
         manned surface platforms).
        --For aircraft-based active sonar activities, mitigation applies
         only to sources that are positively controlled and deployed
         from manned aircraft that do not operate at high altitudes
         (e.g., rotary-wing aircraft). Mitigation does not apply to
         active sonar sources deployed from unmanned aircraft or
         aircraft operating at high altitudes (e.g., maritime patrol
         aircraft).
Number of Lookouts and Observation Platform:
     Hull-mounted sources:
        --1 Lookout: Platforms with space or manning restrictions while
         underway (at the forward part of a small boat or ship) and
         platforms using active sonar while moored or at anchor
         (including pierside).
        --2 Lookouts: Platforms without space or manning restrictions
         while underway (at the forward part of the ship).
     Sources that are not hull-mounted:
        --1 Lookout on the ship or aircraft conducting the activity.
Mitigation Requirements:
     Mitigation zones:
        --Refer to During the activity below.

[[Page 46373]]

 
     Prior to the initial start of the activity (e.g., when
     maneuvering on station):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         relocate or delay the start of active sonar transmission.
     During the activity:
        --Low-frequency active sonar at or above 200 dB or more, and
         hull-mounted mid-frequency active sonar: Navy personnel must
         observe the mitigation zone for marine mammals; Navy personnel
         will power down active sonar transmission by 6 dB if marine
         mammals are observed within 1,000 yd of the sonar source; Navy
         personnel will power down an additional 4 dB (for a total of 10
         dB total) within 500 yd; Navy personnel must cease transmission
         within 200 yd of the sonar source.
        --Low-frequency active sonar below 200 dB, mid-frequency active
         sonar sources that are not hull-mounted, and high-frequency
         active sonar: Navy personnel must observe the mitigation zone
         for marine mammals; Navy personnel will cease active sonar
         transmission if observed within 200 yd of the sonar source.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         or powering up active sonar transmission) until one of the
         following conditions has been met: (1) The animal is observed
         exiting the mitigation zone; (2) the animal is thought to have
         exited the mitigation zone based on a determination of its
         course, speed, and movement relative to the sonar source; (3)
         the mitigation zone has been clear from any additional
         sightings for 10 min. for aircraft-deployed sonar sources or 30
         min for vessel-deployed sonar sources; (4) for mobile
         activities, the active sonar source has transited a distance
         equal to double that of the mitigation zone size beyond the
         location of the last sighting; or (5) for activities using hull-
         mounted sonar, the ship concludes that dolphins are
         deliberately closing in on the ship to ride the ship's bow
         wave, and are therefore out of the main transmission axis of
         the sonar (and there are no other marine mammal sightings
         within the mitigation zone).
------------------------------------------------------------------------


        Table 31--Procedural Mitigation for Weapons Firing Noise
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Weapons firing noise associated with large-caliber gunnery
     activities.
Number of Lookouts and Observation Platform:
     1 Lookout positioned on the ship conducting the firing.
     Depending on the activity, the Lookout could be the same as
     the one described in Procedural Mitigation for Explosive Medium-
     and Large-Caliber Projectiles (Table 34) or Procedural Mitigation
     for Small-, Medium-, and Large-Caliber Non-Explosive Practice
     Munitions (Table 43).
Mitigation Requirements:
     Mitigation Zone:
        --30[deg] on either side of the firing line out to 70 yd from
         the muzzle of the weapon being fired.
     Prior to the initial start of the activity:
        --Navy personnel will observe the mitigation zone for marine
         mammals; if observed, Navy personnel will relocate or delay the
         start of weapons firing.
     During the activity:
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease weapons firing.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         weapons firing) until one of the following conditions has been
         met: (1) The animal is observed exiting the mitigation zone;
         (2) the animal is thought to have exited the mitigation zone
         based on a determination of its course, speed, and movement
         relative to the firing ship; (3) the mitigation zone has been
         clear from any additional sightings for 30 min; or (4) for
         mobile activities, the firing ship has transited a distance
         equal to double that of the mitigation zone size beyond the
         location of the last sighting.
------------------------------------------------------------------------


         Table 32--Procedural Mitigation for Explosive Sonobuoys
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Explosive sonobuoys.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in an aircraft or on a small boat.
     If additional platforms are participating in the activity,
     Navy personnel positioned in those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for marine
     mammals and other applicable biological resources while performing
     their regular duties.
Mitigation Requirements:
     Mitigation Zone:
        --600 yd around an explosive sonobuoy.
     Prior to the initial start of the activity (e.g., during
     deployment of a sonobuoy pattern, which typically lasts 20-30
     minutes):
        --Navy personnel will conduct passive acoustic monitoring for
         marine mammals; Navy personnel will use information from
         detections to assist visual observations.
        --Navy personnel will visually observe the mitigation zone for
         marine mammals; if marine mammals are observed, Navy personnel
         will relocate or delay the start of sonobuoy or source/receiver
         pair detonations.
     During the activity:

[[Page 46374]]

 
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, cease sonobuoy or
         source/receiver pair detonations.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         detonations) until one of the following conditions has been
         met: (1) The animal is observed exiting the mitigation zone;
         (2) the animal is thought to have exited the mitigation zone
         based on a determination of its course, speed, and movement
         relative to the sonobuoy; or (3) the mitigation zone has been
         clear from any additional sightings for 10 min when the
         activity involves aircraft that have fuel constraints, or 30
         min when the activity involves aircraft that are not typically
         fuel constrained.
     After completion of the activity (e.g., prior to
     maneuvering off station):
        --When practical (e.g., when platforms are not constrained by
         fuel restrictions or mission-essential follow-on commitments),
         Navy personnel will observe the vicinity of where detonations
         occurred; if any injured or dead marine mammals are observed,
         Navy personnel will follow established incident reporting
         procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), Navy personnel positioned on these
         assets will assist in the visual observation of the area where
         detonations occurred.
------------------------------------------------------------------------


         Table 33--Procedural Mitigation for Explosive Torpedoes
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Explosive Torpedoes.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in an aircraft.
     If additional platforms are participating in the activity,
     Navy personnel positioned on those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for marine
     mammals and other applicable biological resources while performing
     their regular duties.
Mitigation Requirements:
     Mitigation Zone:
        --2,100 yd around the intended impact location.
     Prior to the initial start of the activity (e.g., during
     deployment of the target):
        --Navy personnel will conduct passive acoustic monitoring for
         marine mammals; Navy personnel will use information from
         detections to assist visual observations.
        --Navy personnel will visually observe the mitigation zone for
         marine mammals; if marine mammals are observed, Navy personnel
         will relocate or delay the start of firing.
     During the activity:
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease firing.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the intended impact location; or (3) the mitigation zone has
         been clear from any additional sightings for 10 min when the
         activity involves aircraft that have fuel constraints, or 30
         min when the activity involves aircraft that are not typically
         fuel constrained.
     After completion of the activity (e.g., prior to
     maneuvering off station):
        --When practical (e.g., when platforms are not constrained by
         fuel restrictions or mission-essential follow-on commitments),
         Navy personnel will observe the vicinity of where detonations
         occurred; if any injured or dead marine mammals are observed,
         Navy personnel will follow established incident reporting
         procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), Navy personnel positioned on these
         assets will assist in the visual observation of the area where
         detonations occurred.
------------------------------------------------------------------------


 Table 34--Procedural Mitigation for Explosive Medium-Caliber and Large-
                           Caliber Projectiles
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Gunnery activities using explosive medium-caliber and large-
     caliber projectiles.
        --Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
     1 Lookout on the vessel or aircraft conducting the
     activity.
        --For activities using explosive large-caliber projectiles,
         depending on the activity, the Lookout could be the same as the
         one described in Weapons Firing Noise (Table 31).
     If additional platforms are participating in the activity,
     Navy personnel positioned on those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for marine
     mammals and other applicable biological resources while performing
     their regular duties.
Mitigation Requirements:
     Mitigation zones:
        --200 yd around the intended impact location for air-to-surface
         activities using explosive medium-caliber projectiles.
        --600 yd around the intended impact location for surface-to-
         surface activities using explosive medium-caliber projectiles.

[[Page 46375]]

 
        --1,000 yd around the intended impact location for surface-to-
         surface activities using explosive large-caliber projectiles.
     Prior to the initial start of the activity (e.g., when
     maneuvering on station):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         relocate or delay the start of firing.
     During the activity:
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease firing.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the intended impact location; (3) the mitigation zone has been
         clear from any additional sightings for 10 min for aircraft-
         based firing or 30 min for vessel-based firing; or (4) for
         activities using mobile targets, the intended impact location
         has transited a distance equal to double that of the mitigation
         zone size beyond the location of the last sighting.
     After completion of the activity (e.g., prior to
     maneuvering off station):
        --When practical (e.g., when platforms are not constrained by
         fuel restrictions or mission-essential follow-on commitments),
         Navy personnel will observe the vicinity of where detonations
         occurred; if any injured or dead marine mammals are observed,
         Navy personnel will follow established incident reporting
         procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), Navy personnel positioned on these
         assets will assist in the visual observation of the area where
         detonations occurred.
------------------------------------------------------------------------


   Table 35--Procedural Mitigation for Explosive Missiles and Rockets
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Aircraft-deployed explosive missiles and rockets.
        --Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in an aircraft.
     If additional platforms are participating in the activity,
     Navy personnel positioned on those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for marine
     mammals and other applicable biological resources while performing
     their regular duties.
Mitigation Requirements:
     Mitigation zones:
        --900 yd around the intended impact location for missiles or
         rockets with 0.6-20 lb net explosive weight.
        --2,000 yd around the intended impact location for missiles with
         21-500 lb net explosive weight.
     Prior to the initial start of the activity (e.g., during a
     fly-over of the mitigation zone):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         relocate or delay the start of firing.
     During the activity:
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease firing.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the intended impact location; or (3) the mitigation zone has
         been clear from any additional sightings for 10 min when the
         activity involves aircraft that have fuel constraints, or 30
         min when the activity involves aircraft that are not typically
         fuel constrained.
     After completion of the activity (e.g., prior to
     maneuvering off station):
        --When practical (e.g., when platforms are not constrained by
         fuel restrictions or mission-essential follow-on commitments),
         Navy personnel will observe the vicinity of where detonations
         occurred; if any injured or dead marine mammals are observed,
         Navy personnel will follow established incident reporting
         procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), Navy personnel positioned on these
         assets will assist in the visual observation of the area where
         detonations occurred.
------------------------------------------------------------------------


           Table 36--Procedural Mitigation for Explosive Bombs
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Explosive bombs.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in the aircraft conducting the
     activity.
     If additional platforms are participating in the activity,
     Navy personnel positioned on those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for marine
     mammals and other applicable biological resources while performing
     their regular duties.
Mitigation Requirements:
     Mitigation zone:

[[Page 46376]]

 
        --2,500 yd around the intended target.
     Prior to the initial start of the activity (e.g., when
     arriving on station):
    --Navy personnel will observe the mitigation zone for marine
     mammals; if marine mammals are observed, Navy personnel will
     relocate or delay the start of bomb deployment.
     During the activity (e.g., during target approach):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease bomb deployment.
         Commencement/recommencement conditions after a marine
         mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         bomb deployment) until one of the following conditions has been
         met: (1) The animal is observed exiting the mitigation zone;
         (2) the animal is thought to have exited the mitigation zone
         based on a determination of its course, speed, and movement
         relative to the intended target; (3) the mitigation zone has
         been clear from any additional sightings for 10 min; or (4) for
         activities using mobile targets, the intended target has
         transited a distance equal to double that of the mitigation
         zone size beyond the location of the last sighting.
         After completion of the activity (e.g., prior to
         maneuvering off station):
        --When practical (e.g., when platforms are not constrained by
         fuel restrictions or mission-essential follow-on commitments),
         Navy personnel will observe the vicinity of where detonations
         occurred; if any injured or dead marine mammals are observed,
         Navy personnel will follow established incident reporting
         procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), Navy personnel positioned on these
         assets will assist in the visual observation of the area where
         detonations occurred.
------------------------------------------------------------------------


          Table 37--Procedural Mitigation for Sinking Exercises
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Sinking exercises.
Number of Lookouts and Observation Platform:
     2 Lookouts (one positioned in an aircraft and one on a
     vessel).
     If additional platforms are participating in the activity,
     Navy personnel positioned on those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for marine
     mammals and other applicable biological resources while performing
     their regular duties.
Mitigation Requirements:
     Mitigation Zone:
        --2.5 nmi around the target ship hulk.
     Prior to the initial start of the activity (90 min prior to
     the first firing):
        --Navy personnel will conduct aerial observations of the
         mitigation zone for marine mammals; if marine mammals are
         observed, Navy personnel will delay the start of firing.
     During the activity:
        --Navy personnel will conduct passive acoustic monitoring for
         marine mammals; Navy personnel will use information from
         detections to assist visual observations.
        --Navy personnel will visually observe the mitigation zone for
         marine mammals from the vessel; if marine mammals are observed,
         Navy personnel must cease firing.
        --Immediately after any planned or unplanned breaks in weapons
         firing of longer than 2 hours, Navy personnel will observe the
         mitigation zone for marine mammals from the aircraft and
         vessel; if marine mammals are observed, Navy personnel must
         delay recommencement of firing.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the target ship hulk; or (3) the mitigation zone has been clear
         from any additional sightings for 30 min.
     After completion of the activity (for 2 hours after sinking
     the vessel or until sunset, whichever comes first):
        --Navy personnel will observe the vicinity of where detonations
         occurred; if any injured or dead marine mammals are observed,
         Navy personnel will follow established incident reporting
         procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), Navy personnel positioned on these
         assets will assist in the visual observation of the area where
         detonations occurred.
------------------------------------------------------------------------


  Table 38--Procedural Mitigation for Explosive Mine Countermeasure and
                        Neutralization Activities
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Explosive mine countermeasure and neutralization
     activities.
Number of Lookouts and Observation Platform:
     1 Lookout positioned on a vessel or in an aircraft.
     If additional platforms are participating in the activity,
     Navy personnel positioned on those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for marine
     mammals and other applicable biological resources while performing
     their regular duties.
Mitigation Requirements:

[[Page 46377]]

 
     Mitigation Zone:
        --600 yd around the detonation site.
     Prior to the initial start of the activity (e.g., when
     maneuvering on station; typically, 10 min when the activity
     involves aircraft that have fuel constraints, or 30 min when the
     activity involves aircraft that are not typically fuel
     constrained):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         relocate or delay the start of detonations.
     During the activity:
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease detonations.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         detonations) until one of the following conditions has been
         met: (1) The animal is observed exiting the mitigation zone;
         (2) the animal is thought to have exited the mitigation zone
         based on a determination of its course, speed, and movement
         relative to detonation site; or (3) the mitigation zone has
         been clear from any additional sightings for 10 min when the
         activity involves aircraft that have fuel constraints, or 30
         min. when the activity involves aircraft that are not typically
         fuel constrained.
     After completion of the activity (typically 10 min when the
     activity involves aircraft that have fuel constraints, or 30 min
     when the activity involves aircraft that are not typically fuel
     constrained):
        --Navy personnel will observe the vicinity of where detonations
         occurred; if any injured or dead marine mammals are observed,
         Navy personnel will follow established incident reporting
         procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), Navy personnel positioned on these
         assets will assist in the visual observation of the area where
         detonations occurred.
------------------------------------------------------------------------


    Table 39--Procedural Mitigation for Explosive Mine Neutralization
                    Activities Involving Navy Divers
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Explosive mine neutralization activities involving Navy
     divers.
Number of Lookouts and Observation Platforms:
     2 Lookouts (two small boats with one Lookout each, or one
     Lookout on a small boat and one in a rotary-wing aircraft) when
     implementing the smaller mitigation zone.
     4 Lookouts (two small boats with two Lookouts each), and a
     pilot or member of an aircrew will serve as an additional Lookout
     if aircraft are used during the activity, when implementing the
     larger mitigation zone.
     All divers placing the charges on mines will support the
     Lookouts while performing their regular duties and will report
     applicable sightings to their supporting small boat or Range Safety
     Officer.
     If additional platforms are participating in the activity,
     Navy personnel positioned on those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for marine
     mammals and other applicable biological resources while performing
     their regular duties.
Mitigation Requirements:
     Mitigation Zones:
        --For Lookouts on small boats or aircraft: 500 yd around the
         detonation site during activities under positive control.
        --For Lookouts on small boats or aircraft: 1,000 yd around the
         detonation site during activities using time-delay fuses.
        --For divers: The underwater detonation location, which is
         defined as the sea space within the divers' range of visibility
         but no further than the mitigation zone specified for Lookouts
         on small boats or aircraft (500 yd or 1,000 yd depending on the
         charge type).
     Prior to the initial start of the activity (when
     maneuvering on station for activities under positive control; 30
     min for activities using time-delay firing devices):
        --Lookouts on small boats or aircraft will observe the
         mitigation zone for marine mammals; if marine mammals are
         observed, Navy personnel will relocate or delay the start of
         detonations or fuse initiation.
     During the activity:
        --Lookouts on small boats or aircraft will observe the
         mitigation zone for marine mammals; if marine mammals are
         observed, Navy personnel will cease detonations or fuse
         initiation.
        --While performing their normal duties, during the activity.
         divers will observe the underwater detonation location for
         marine mammals. Divers will notify their supporting small boat
         or Range Safety Officer of marine mammal sightings at the
         underwater detonation location; if observed, Navy personnel
         will cease detonations or fuse initiation.
        --To the maximum extent practical depending on mission
         requirements, safety, and environmental conditions, boats will
         position themselves near the mid-point of the mitigation zone
         radius (but outside of the detonation plume and human safety
         zone), will position themselves on opposite sides of the
         detonation location (when two boats are used), and will travel
         in a circular pattern around the detonation location with one
         Lookout observing inward toward the detonation site and the
         other observing outward toward the perimeter of the mitigation
         zone.
        --If used, aircraft will travel in a circular pattern around the
         detonation location to the maximum extent practicable.
        --Navy personnel will not set time-delay firing devices to
         exceed 10 min.
     Commencement/recommencement conditions after a marine
     mammal before or during the activity:

[[Page 46378]]

 
        --Navy personnel will allow a sighted marine mammal to leave the
         underwater detonation location or mitigation zone (as
         applicable) prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         detonations or fuse initiation) until one of the following
         conditions has been met: (1) The animal is observed exiting the
         500 yd or 1,000 yd mitigation zone; (2) the animal is thought
         to have exited the 500 yd or 1,000 yd mitigation zone based on
         a determination of its course, speed, and movement relative to
         the detonation site; or (3) the 500 yd or 1,000 yd mitigation
         zone ((for Lookouts on small boats or aircraft) and the
         underwater detonation location (for divers)) has been clear
         from any additional sightings for 10 min during activities
         under positive control with aircraft that have fuel
         constraints, or 30 min during activities under positive control
         with aircraft that are not typically fuel constrained and
         during activities using time-delay firing devices.
     After completion of an activity (for 30 min):
        --Navy personnel will observe the vicinity of where detonations
         occurred; if any injured or dead marine mammals are observed,
         Navy personnel will follow established incident reporting
         procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), Navy personnel positioned on these
         assets will assist in the visual observation of the area where
         detonations occurred.
------------------------------------------------------------------------


 Table 40--Procedural Mitigation for Maritime Security Operations--Anti-
                            Swimmer Grenades
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Maritime Security Operations--Anti-Swimmer Grenades.
Number of Lookouts and Observation Platform:
     1 Lookout positioned on the small boat conducting the
     activity.
     If additional platforms are participating in the activity,
     Navy personnel positioned on those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for marine
     mammals and other applicable biological resources while performing
     their regular duties.
Mitigation Requirements:
     Mitigation zone:
        --200 yd around the intended detonation location.
     Prior to the initial start of the activity (e.g., when
     maneuvering on station):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         relocate or delay the start of detonations.
     During the activity:
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease detonations.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         detonations) until one of the following conditions has been
         met: (1) The animal is observed exiting the mitigation zone;
         (2) the animal is thought to have exited the mitigation zone
         based on a determination of its course, speed, and movement
         relative to the intended detonation location; (3) the
         mitigation zone has been clear from any additional sightings
         for 30 min; or (4) the intended detonation location has
         transited a distance equal to double that of the mitigation
         zone size beyond the location of the last sighting.
     After completion of the activity (e.g., prior to
     maneuvering off station):
        --When practical (e.g., when platforms are not constrained by
         fuel restrictions or mission-essential follow-on commitments),
         Navy personnel will observe the vicinity of where detonations
         occurred; if any injured or dead marine mammals are observed,
         Navy personnel will follow established incident reporting
         procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), Navy personnel positioned on these
         assets will assist in the visual observation of the area where
         detonations occurred.
------------------------------------------------------------------------


           Table 41--Procedural Mitigation for Vessel Movement
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Vessel movement:
        --The mitigation will not be applied if (1) the vessel's safety
         is threatened, (2) the vessel is restricted in its ability to
         maneuver (e.g., during launching and recovery of aircraft or
         landing craft, during towing activities, when mooring, etc.),
         (3) the vessel is submerged or operated autonomously, or (4)
         when impractical based on mission requirements (e.g., during
         Amphibious Assault and Amphibious Raid exercises).
Number of Lookouts and Observation Platform:
     1 Lookout on the vessel that is underway.
Mitigation Requirements:
     Mitigation Zones:
        --500 yd around whales.
        --200 yd around other marine mammals (except bow-riding
         dolphins).
     During the activity:
        --When underway, Navy personnel will observe the mitigation zone
         for marine mammals; if marine mammals are observed, Navy
         personnel will maneuver to maintain distance.

[[Page 46379]]

 
     Additional requirements:
        --If a marine mammal vessel strike occurs, Navy personnel will
         follow the established incident reporting procedures.
------------------------------------------------------------------------


       Table 42--Procedural Mitigation for Towed In-Water Devices
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Towed in-water devices:
        --Mitigation applies to devices that are towed from a manned
         surface platform or manned aircraft.
        --The mitigation will not be applied if the safety of the towing
         platform or in-water device is threatened.
Number of Lookouts and Observation Platform:
     1 Lookout positioned on a manned towing platform.
Mitigation Requirements:
     Mitigation Zones:
        --250 yd. around marine mammals.
     During the activity (i.e., when towing an in-water device):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         maneuver to maintain distance.
------------------------------------------------------------------------


 Table 43--Procedural Mitigation for Small-, Medium-, and Large-Caliber
                    Non-Explosive Practice Munitions
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Gunnery activities using small-, medium-, and large-caliber
     non-explosive practice munitions.
        --Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
     1 Lookout positioned on the platform conducting the
     activity.
     Depending on the activity, the Lookout could be the same as
     the one described in Procedural Mitigation for Weapons Firing Noise
     (Table 31).
Mitigation Requirements:
     Mitigation Zone:
        --200 yd around the intended impact location.
     Prior to the initial start of the activity (e.g., when
     maneuvering on station):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         relocate or delay the start of firing.
     During the activity:
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease firing.
     Commencement/recommencement conditions after a marine
     mammal sighting before or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the intended impact location; (3) the mitigation zone has been
         clear from any additional sightings for 10 min for aircraft-
         based firing or 30 min for vessel-based firing; or (4) for
         activities using a mobile target, the intended impact location
         has transited a distance equal to double that of the mitigation
         zone size beyond the location of the last sighting.
------------------------------------------------------------------------


 Table 44--Procedural Mitigation for Non-Explosive Missiles and Rockets
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Aircraft-deployed non-explosive missiles and rockets.
     Mitigation applies to activities using a surface target.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in an aircraft.
Mitigation Requirements:
     Mitigation Zone:
        --900 yd around the intended impact location.
     Prior to the initial start of the activity (e.g., during a
     fly-over of the mitigation zone):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         relocate or delay the start of firing.
     During the activity:
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease firing.
     Commencement/recommencement conditions after a marine
     mammal sighting prior to or during the activity:

[[Page 46380]]

 
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the intended impact location; or (3) the mitigation zone has
         been clear from any additional sightings for 10 min when the
         activity involves aircraft that have fuel constraints, or 30
         min when the activity involves aircraft that are not typically
         fuel constrained.
------------------------------------------------------------------------


 Table 45--Procedural Mitigation for Non-Explosive Bombs and Mine Shapes
------------------------------------------------------------------------
                    Procedural Mitigation Description
-------------------------------------------------------------------------
Stressor or Activity:
     Non-explosive bombs.
     Non-explosive mine shapes during mine laying activities.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in an aircraft.
Mitigation Requirements:
     Mitigation Zone:
        --1,000 yd around the intended target.
     Prior to the initial start of the activity (e.g., when
     arriving on station):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         relocate or delay the start of bomb deployment or mine laying.
     During the activity (e.g., during approach of the target or
     intended minefield location):
        --Navy personnel will observe the mitigation zone for marine
         mammals; if marine mammals are observed, Navy personnel will
         cease bomb deployment or mine laying.
     Commencement/recommencement conditions after a marine
     mammal sighting prior to or during the activity:
        --Navy personnel will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         bomb deployment or mine laying) until one of the following
         conditions has been met: (1) The animal is observed exiting the
         mitigation zone; (2) the animal is thought to have exited the
         mitigation zone based on a determination of its course, speed,
         and movement relative to the intended target or minefield
         location; (3) the mitigation zone has been clear from any
         additional sightings for 10 min; or (4) for activities using
         mobile targets, the intended target has transited a distance
         equal to double that of the mitigation zone size beyond the
         location of the last sighting.
------------------------------------------------------------------------

Mitigation Areas

    In addition to procedural mitigation, the Navy will implement 
mitigation measures within mitigation areas to avoid or minimize 
potential impacts on marine mammals. A full technical analysis (for 
which the methods were discussed above) of the mitigation areas that 
the Navy considered for marine mammals is provided in Appendix I 
(Geographic Mitigation Assessment) of the 2020 MITT FSEIS/OEIS. NMFS 
and the Navy took into account public comments received on the 2019 
MITT DSEIS/OEIS and the 2019 MITT proposed rule, best available 
science, and the practicability of implementing additional mitigation 
measures and has enhanced the mitigation areas and mitigation measures, 
beyond the 2015-2020 regulations, to further reduce impacts to marine 
mammals.
    Information on the mitigation measures that the Navy will implement 
within mitigation areas is provided in Table 46 (see below). The 
mitigation applies year-round unless specified otherwise in the table.
    NMFS conducted an independent analysis of the mitigation areas that 
the Navy will implement and that are included in this rule, which are 
described below, in Table 46. NMFS' analysis indicates that the 
measures in these mitigation areas will reduce the likelihood or 
severity of adverse impacts to marine mammal species or their habitat 
in the manner described in this rule and are practicable for the Navy. 
NMFS is heavily reliant on the Navy's description of operational 
practicability, since the Navy is best equipped to describe the degree 
to which a given mitigation measure affects personnel safety or mission 
effectiveness, and is practical to implement. The Navy considers the 
measures in this rule to be practicable, and NMFS concurs. We further 
discuss the manner in which the Geographic Mitigation Areas in the rule 
will reduce the likelihood or severity of adverse impacts to marine 
mammal species or their habitat below.

  Table 46--Geographic Mitigation Areas for Marine Mammals in the MITT
                               Study Area
------------------------------------------------------------------------
                       Mitigation Area Description
-------------------------------------------------------------------------
Stressor or Activity:
     Sonar.
     In-water Explosives.
Mitigation Requirements:
     Marpi Reef and Chalan Kanoa Reef Geographic Mitigation
     Areas (Figures 1 and 2):
        --Navy personnel will conduct a maximum annual total of 20 hours
         of surface ship hull-mounted MF1 mid-frequency active sonar
         from December 1 through April 30 within the Marpi Reef and
         Chalan Kanoa Reef Geographic Mitigation Areas combined (20
         hours total for both areas).
        --Navy personnel will report the total hours of active sonar
         (all bins, by bin) used in the Marpi Reef and Chalan Kanoa Reef
         Geographic Mitigation Areas from December 1 through April 30 in
         the annual training and testing exercise report submitted to
         NMFS.
        --Navy personnel will not use in-water explosives in the Marpi
         Reef and Chalan Kanoa Reef Geographic Mitigation Areas year-
         round.

[[Page 46381]]

 
        --Navy personnel will issue an annual seasonal awareness
         notification message to alert Navy ships and aircraft operating
         in the Marpi Reef and Chalan Kanoa Reef Geographic Mitigation
         Areas to the possible presence of increased concentrations of
         humpback whales from December 1 through April 30. To maintain
         safety of navigation and to avoid interactions with large
         whales during transits, Navy personnel will instruct vessels to
         remain vigilant to the presence of humpback whales, that when
         concentrated seasonally, may become vulnerable to vessel
         strikes. Navy personnel will use the information from the
         awareness notification messages to assist their visual
         observation of applicable mitigation zones during training and
         testing activities and to aid in the implementation of
         procedural mitigation.
        --Should national security present a requirement to conduct
         training or testing prohibited by the mitigation requirements
         specified in this table, Navy personnel will obtain permission
         from the appropriate designated Command authority prior to
         commencement of the activity. Navy personnel will provide NMFS
         with advance notification and include relevant information
         (e.g., sonar hours, explosives use) in its annual activity
         reports submitted to NMFS.
     Agat Bay Nearshore Geographic Mitigation Area (Figure 3):
        --Navy personnel will not use surface ship hull-mounted MF1 mid-
         frequency active sonar in the Agat Bay Nearshore Geographic
         Mitigation Area year-round.
        --Navy personnel will not use in-water explosives in the Agat
         Bay Nearshore Mitigation Area year-round.
        --Should national security require the use of MF1 surface ship
         hull-mounted mid-frequency active sonar or explosives
         prohibited by the mitigation requirements, Navy personnel will
         obtain permission from the appropriate designated Command
         authority prior to commencement of the activity. Navy personnel
         will provide NMFS with advance notification and include
         relevant information (e.g., sonar hours, explosives use) in the
         annual activity reports submitted to NMFS.
------------------------------------------------------------------------

Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas
    The proposed rule included a restriction on the use of explosives 
in these two mitigation areas, but no limitation on the use of active 
sonar. The final rule includes a 20-hour annual cap from December 1 
through April 30 on the use of hull-mounted MF1 mid-frequency active 
sonar during training and testing activities within the Marpi Reef and 
Chalan Kanoa Reef Geographic Mitigation Areas (20 hours for both areas 
combined). In addition to the reporting of the total hours of surface 
ship hull-mounted MF1 mid-frequency active sonar, the Navy will now 
also report all sonar sources used (all bins, by bin) within the Chalan 
Kanoa and Marpi Reef Geographic Mitigation Areas from December 1 to 
April 30 in the annual MITT classified Exercise Reports. This will 
provide NMFS with more specific data in order to evaluate sonar use 
with current mitigation measures in the geographic mitigation areas and 
to determine if any changes are needed through Adaptive Management.
    While the shallower water within the Chalan Kanoa Reef and Marpi 
Reef Geographic Mitigation Areas has not been a high-use area for Navy 
MTEs and ASW training events as the area is considered generally less 
suitable (Navy training is more typically conducted beyond 3 nmi from 
shore and in waters greater than 200-m depth, with MTEs typically far 
offshore), the Navy has stressed the broader need for flexibility as 
well as the specific need not to restrict training areas entirely in 
this part of the MITT Study Area given the proximity to forward 
deployed operations (i.e., U.S. 7th fleet's continuous presence in the 
Indo-Pacific region, which is a National Defense Strategy priority 
theater of operation) and the need to have the option to conduct 
training quickly and to respond to emergent national security threats.
    Following extensive discussions with the Navy through which more 
specific information about the Navy's likely activity in the Chalan 
Kanoa Reef and Marpi Reef Geographic Mitigation Areas was provided, new 
information about humpback whale occurrence in the two Geographic 
Mitigation Areas emerged, and new analyses were conducted (see the 
Estimated Take of Marine Mammals section). NMFS has included a 
requirement for the Navy to implement the annual 20-hr cap from 
December 1 through April 30 on hull-mounted MF1 MFAS within the two 
Geographic Mitigation Areas to minimize sonar exposure and reduce take 
by Level B harassment of humpback whales in this important reproductive 
area.
    To determine the extent of the Marpi Reef and Chalan Kanoa Reef 
Geographic Mitigation Areas, the Navy obtained all humpback whale 
sighting data from 2015-2019 in the Marianas from NMFS' PIFSC (Figures 
1 and 2). As described in the Description of Marine Mammals and Their 
Habitat in the Area of the Specified Activities section of the rule, 
humpback whales, including mother-calf pairs, have been seasonally 
present in shallow waters (out to the 400-m isobath) and the science 
indicates the areas may be of biological importance to humpback whales 
for biologically important life processes associated with reproduction 
(e.g., breeding, birthing, and nursing) during the winter months, 
generally December through April.
    Calves are considered more sensitive and susceptible to adverse 
impacts from Navy stressors than adults (especially given their lesser 
weight and the association between weight and explosive impacts), as 
well as being especially reliant upon mother-calf communication for 
protection and guidance. Both gestation and lactation increase energy 
demands for mothers. Breeding activities typically involve 
vocalizations and complex social interactions that can include violent 
interactions between males. Reducing exposure of humpback whales to 
explosive detonations and sonar use in the Marpi Reef and Chalan Kanoa 
Reef Geographic Mitigation Areas during the months of December through 
April is expected to reduce the likelihood of impacts that could affect 
reproduction or survival of individual animals, by minimizing impacts 
on calves during this sensitive life stage, avoiding or minimizing the 
additional energetic costs to mothers of avoiding or leaving the area 
during explosives exercises and sonar use, and minimizing the chances 
that important breeding behaviors are interrupted to the point that 
reproduction is inhibited or abandoned for the year, or otherwise 
interfered with.
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[[Page 46382]]

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[[Page 46383]]


[GRAPHIC] [TIFF OMITTED] TR31JY20.009


[[Page 46384]]


Agat Bay Nearshore Geographic Mitigation Area
    The Agat Bay Nearshore Geographic Mitigation Area encompasses the 
shoreline between Tipalao, Dadi Beach, and Agat on the west coast of 
Guam, with a boundary across the bay enclosing an area of approximately 
5 km\2\ in relatively shallow waters (less than 100 m). The boundaries 
of the Agat Bay Nearshore Geographic Mitigation Area (Figure 3) were 
defined by Navy scientists based on spinner dolphin sightings 
documented during small boat surveys from 2010 through 2014. Spinner 
dolphins have been the most frequently encountered species during small 
boat reconnaissance surveys conducted in the Mariana Islands since 
2010. Consistent with more intensive studies completed for the species 
in the Hawaiian Islands, island-associated spinner dolphins are 
expected to occur in shallow water resting areas (about 50 m deep or 
less) in the morning and throughout the middle of the day, moving into 
deep waters offshore during the night to feed (Heenehan et al., 2016b; 
Heenehan et al., 2017a; Hill et al., 2010; Norris and Dohl, 1980). The 
best available science, as described above, indicates that Agat Bay is 
important resting habitat for spinner dolphins.
    Behavioral disruptions during resting periods can adversely impact 
health and energetic budgets by not allowing spinner dolphins to get 
the needed rest and/or by creating the need to travel and expend 
additional energy to find other suitable resting areas. Avoiding sonar 
and explosives in this geographic mitigation area year-round reduces 
the likelihood of energetic impacts that could accrue and affect 
reproduction or survival of these individuals.

[[Page 46385]]

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BILLING CODE 3510-22-C

Mitigation Conclusions

    NMFS has carefully evaluated the Navy's mitigation measures--many 
of which were developed with NMFS' input during the previous phases of 
Navy training and testing authorizations but several of which are new 
since implementation of the 2015 to 2020 regulations--and considered a 
broad range of other measures (i.e., the measures considered but 
eliminated in the 2020 MITT FSEIS/OEIS, which reflect many of the 
comments that have arisen via NMFS or public input in past years) in 
the context of ensuring that NMFS prescribes the means of effecting the 
least practicable adverse impact on the affected marine mammal species 
and their habitat. Our evaluation of potential measures included 
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 the likelihood and/or 
magnitude of adverse impacts to marine mammal species and their 
habitat; the proven or likely efficacy of the measures; and the 
practicability of the measures for applicant implementation, including 
consideration of personnel safety, practicality of implementation, and

[[Page 46386]]

impact on the effectiveness of the military readiness activity.
    Based on our evaluation of the Navy's measures, as well as other 
measures considered by the Navy and NMFS, NMFS has determined that the 
mitigation measures included in this final rule are the appropriate 
means of effecting the least practicable adverse impact on the marine 
mammal species and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and 
considering specifically personnel safety, practicality of 
implementation, and impact on the effectiveness of the military 
readiness activity. Additionally, an adaptive management provision 
ensures that mitigation is regularly assessed and provides a mechanism 
to improve the mitigation, based on the factors above, through 
modification as appropriate. Thus, NMFS concludes that the mitigation 
measures outlined in this final rule satisfy the statutory standard and 
that any adverse impacts that remain cannot practicably be further 
mitigated.

Monitoring

    Section 101(a)(5)(A) of the MMPA states that in order to authorize 
incidental take 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 incidental take authorizations 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.
    Although the Navy has been conducting research and monitoring in 
the MITT Study Area for over 20 years, it developed a formal marine 
species monitoring program in support of the MMPA and ESA 
authorizations in 2009. This robust program has resulted in hundreds of 
technical reports and publications on marine mammals that have informed 
Navy and NMFS analyses in environmental planning documents, rules, and 
ESA Biological Opinions. The reports are made available to the public 
on the Navy's marine species monitoring website 
(www.navymarinespeciesmonitoring.us) and the data on the Ocean 
Biogeographic Information System Spatial Ecological Analysis of 
Megavertebrate Populations (OBIS-SEAMAP) (http://seamap.env.duke .edu/
).
    The Navy will continue collecting monitoring data to inform our 
understanding of the occurrence of marine mammals in the MITT Study 
Area; the likely exposure of marine mammals to stressors of concern in 
the MITT Study Area; the response of marine mammals to exposures to 
stressors; the consequences of a particular marine mammal response to 
their individual fitness and, ultimately, populations; and the 
effectiveness of implemented mitigation measures. Taken together, 
mitigation and monitoring comprise the Navy's integrated approach for 
reducing environmental impacts from the specified activities. The 
Navy's overall monitoring approach seeks to leverage and build on 
existing research efforts whenever possible.
    As agreed upon between the Navy and NMFS, the monitoring measures 
presented here, as well as the mitigation measures described above, 
focus on the protection and management of potentially affected marine 
mammals. A well-designed monitoring program can provide important 
feedback for validating assumptions made in analyses and allow for 
adaptive management of marine resources. Monitoring is required under 
the MMPA, and details of the monitoring program for the specified 
activities have been developed through coordination between NMFS and 
the Navy through the regulatory process for previous Navy at-sea 
training and testing activities.

Integrated Comprehensive Monitoring Program (ICMP)

    The Navy's ICMP is intended to coordinate marine species 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. This process includes conducting an annual adaptive 
management review meeting, at which the Navy and NMFS jointly consider 
the prior-year goals, monitoring results, and related scientific 
advances to determine if monitoring plan modifications are warranted to 
more effectively address program goals. Although the ICMP does not 
specify actual monitoring field work or individual projects, it does 
establish a matrix of goals and objectives that have been developed in 
coordination with NMFS. As the ICMP is implemented through the 
Strategic Planning Process, detailed and specific studies are developed 
which support the Navy's and NMFS' 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., sound, explosive detonation, or military expended materials) 
through better understanding of the following: (1) The action and the 
environment in which it occurs (e.g., sound source characterization, 
propagation, and ambient noise levels); (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); 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 Navy complies with the incidental take regulations and LOAs and the 
ESA Incidental Take Statement;
     An increase in the probability of detecting marine mammals 
(through improved technology or methods), both specifically within the 
mitigation zone (thus allowing for more effective

[[Page 46387]]

implementation of the mitigation) and in general, to better achieve the 
above goals; and
     Ensuring that adverse impact of activities remains at the 
least practicable level.

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 intermediate scientific objectives and a 
conceptual framework incorporating a progression of knowledge spanning 
occurrence, exposure, response, and consequence. The Strategic Planning 
Process for Marine Species Monitoring is used to set overarching 
intermediate scientific objectives; develop individual monitoring 
project concepts; identify potential species of interest at a regional 
scale; evaluate, prioritize and select specific monitoring projects to 
fund or continue supporting for a given fiscal year; execute and manage 
selected monitoring projects; and report and evaluate progress and 
results. This process addresses relative investments to different range 
complexes based on goals across all range complexes, and monitoring 
will 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 and Current Monitoring in the MITT Study Area

    The monitoring program has undergone significant changes since the 
first rule was issued for the MITT Study Area in 2009, which highlights 
the monitoring program's evolution through the process of adaptive 
management. The monitoring program developed for the first cycle of 
environmental compliance documents (e.g., U.S. Department of the Navy, 
2008) utilized effort-based compliance metrics that were somewhat 
limiting. Through adaptive management discussions, the Navy designed 
and conducted monitoring studies according to scientific objectives, 
thereby eliminating basing requirements upon metrics of level-of-
effort. Furthermore, refinements of scientific objective have continued 
through the latest authorization cycle.
    Progress has also been made on the conceptual framework categories 
from the Scientific Advisory Group for Navy Marine Species Monitoring 
(U.S. Department of the Navy, 2011c), ranging from occurrence of 
animals, to their exposure, response, and population consequences. The 
Navy continues to manage the Atlantic and Pacific program as a whole, 
with monitoring in each range complex taking a slightly different but 
complementary approach. The Navy has continued to use the approach of 
layering multiple simultaneous components in many of the range 
complexes to leverage an increase in return of the progress toward 
answering scientific monitoring questions. This includes, in the 
Marianas for example, (a) glider deployment in offshore areas, (b) 
analysis of existing passive acoustic monitoring datasets, (c) small 
boat surveys using visual, biopsy, and satellite tagging and (d) 
seasonal, humpback whale specific surveys.
    Specific monitoring under the 2015-2020 regulations includes:
    [ssquf] Review of the available data and analyses in the MITT Study 
Area 2010 through February 2018 (2019a).
    [ssquf] The continuation of annual small vessel nearshore surveys, 
sightings, satellite tagging, biopsy and genetic analysis, photo-
identification, and opportunistic acoustic recording off Guam, Saipan, 
Tinian, Rota, and Aguigan in partnership with NMFS (Hill et al., 2015; 
Hill et al., 2016b; Hill et al., 2017a; Hill et al., 2018, Hill et al., 
2019b). The satellite tagging and genetic analyses have resulted in the 
first information discovered on the movement patterns, habitat 
preference, and population structure of multiple odontocete species in 
the MITT Study Area.
    [ssquf] Since 2015, the addition of a series of small vessel 
surveys in the winter season dedicated to humpback whales has provided 
new information relating to the occurrence, calving behavior, and 
population identity of this species (Hill et al., 2016a; Hill et al., 
2017b), which had not previously been sighted during the small vessel 
surveys in the summer or winter. This work has included sighting data, 
photo ID matches of individuals to other areas demonstrating migration 
as well as re-sights within the Marianas across different years, and 
the collection of biopsy samples for genetic analyses of populations.
    [ssquf] The continued deployment of passive acoustic monitoring 
devices and analysis of acoustic data obtained using bottom-moored 
acoustic recording devices deployed by NMFS has provided information on 
the presence and seasonal occurrence of mysticetes, as well as the 
occurrence of cryptic odontocetes typically found offshore, including 
beaked whales and Kogia spp. (Hill et al., 2015; Hill et al., 2016a; 
Hill et al., 2016b; Hill et al., 2017a; Munger et al., 2015; Norris et 
al., 2017; Oleson et al., 2015; Yack et al., 2016).
    [ssquf] Acoustic surveys using autonomous gliders were used to 
characterize the occurrence of odontocetes and mysticetes in abyssal 
offshore waters near Guam and CNMI, including species not seen in the 
small vessel visual survey series such as killer whales and Risso's 
dolphins. Analysis of collected data also provided new information on 
the seasonality of baleen whales, patterns of beaked whale occurrence 
and potential call variability, and identification of a new unknown 
marine mammal call (Klinck et al., 2016b; Nieukirk et al., 2016).
    [ssquf] Visual surveys were conducted from a shore-station at high 
elevation on the north shore of Guam to document the nearshore 
occurrence of marine mammals in waters where small vessel visual 
surveys are challenging due to regularly high sea states (Deakos & 
Richlen, 2015; Deakos et al., 2016).
    [ssquf] Analysis of archive data that included marine mammal 
sightings during Guam Department of Agriculture Division of Aquatic and 
Wildlife Resources aerial surveys undertaken between 1963 and 2012 
(Martin et al., 2016).
    [ssquf] Analysis of archived acoustic towed-array data for an 
assessment of the abundance and density of minke whales (Norris et al., 
2017), abundance and density of sperm whales (Yack et al., 2016), and 
the characterization of sei and humpback whale vocalizations (Norris et 
al., 2014).
    Numerous publications, dissertations, and conference presentations 
have resulted from research conducted under the Navy's marine species 
monitoring program (https://www.navymarinespeciesmonitoring.us/reading-room/publications/), resulting in a significant contribution to the 
body of marine mammal science. Publications on occurrence, 
distribution, and density have fed the modeling input, and publications 
on exposure and response have informed Navy and NMFS analyses of 
behavioral response and consideration of mitigation measures.
    Furthermore, collaboration between the monitoring program and the 
Navy's research and development (e.g., the Office of Naval Research) 
and demonstration-validation (e.g., Living Marine Resources) programs 
has been strengthened, leading to research tools and products that have 
already transitioned to the monitoring program. These include Marine 
Mammal Monitoring on Ranges (M3R), controlled

[[Page 46388]]

exposure experiment behavioral response studies (CEE BRS), acoustic sea 
glider surveys, and global positioning system-enabled satellite tags. 
Recent progress has been made with better integration of monitoring 
across all Navy at-sea study areas, including study areas in the 
Pacific and the Atlantic Oceans, and various testing ranges. 
Publications from the Living Marine Resources and the Office of Naval 
Research programs have also resulted in significant contributions to 
information on hearing ranges and acoustic criteria used in effects 
modeling, exposure, and response, as well as developing tools to assess 
biological significance (e.g., population-level consequences).
    NMFS and the Navy also consider data collected during procedural 
mitigations as monitoring. Data are collected by shipboard personnel on 
hours spent training, hours of observation, hours of sonar, and marine 
mammals observed within the mitigation zones when mitigations are 
implemented. These data are provided to NMFS in both classified and 
unclassified annual exercise reports, which will continue under this 
rule.
    NMFS has received multiple years' worth of annual exercise and 
monitoring reports addressing active sonar use and explosive 
detonations within the MITT Study Area and other Navy range complexes. 
The data and information contained in these reports have been 
considered in developing mitigation and monitoring measures for the 
training and testing activities within the MITT Study Area. The Navy's 
annual exercise and monitoring reports may be viewed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities and http://www.navymarinespeciesmonitoring.us.
    Prior to Phase I monitoring, the information on marine mammal 
presence and occurrence in the MIRC was largely absent and limited to 
anecdotal information from incidental sightings and stranding events 
(U.S. Department of the Navy, 2005). In 2007, the Navy funded the 
Mariana Islands Sea Turtle and Cetacean Survey (MISTCS) (U.S. 
Department of the Navy, 2007) to proactively support the baseline data 
feeding the MIRC EIS (U.S. Department of the Navy, 2010b). The MISTCS 
research effort was the first systematic marine survey in these waters. 
This survey provided the first empirically-based density estimates for 
marine mammals (Fulling et al., 2011). In cooperation with NMFS, the 
Phase I monitoring program beginning in 2010 was designed to address 
basic occurrence-level questions in the MIRC, whereas monitoring the 
impacts of Navy training such as exposure to mid-frequency active sonar 
was planned for other Navy range complexes where marine mammal 
occurrence was already better characterized.
    This emphasis on studying occurrence continued through Phase I and 
II monitoring in the MIRC, and combined various complementary 
methodologies. Small vessel visual surveys collected occurrence 
information, and began building the first individual identification 
catalog for multiple species (Hill et al., 2014). During these visual 
surveys, biopsies were collected for genetic analysis and satellite 
tags were also applied, resulting in a progressively improving picture 
of the habitat use and population structure of various species. Deep 
water passive acoustic deployments, including autonomous gliders with 
passive acoustic recorders, added complementary information on species 
groups such as baleen whales and beaked whales that were rarely sighted 
on the vessel surveys (Klinck et al., 2015; Munger et al., 2014; Munger 
et al., 2015; Nieukirk et al., 2016; Norris et al., 2015). Other 
methodologies were also explored to fill other gaps in waters generally 
inaccessible to the small boat surveys including a shore-station to 
survey waters on the windward side of Guam (Deakos et al., 2016). When 
available, platforms of opportunity on large vessels were utilized for 
visual survey and tagging (Oleson and Hill, 2010b).
    At the close of Phase II monitoring, establishing the fundamentals 
of marine mammal occurrence in the MITT Study Area had been 
significantly advanced. The various visual and acoustic platforms have 
encountered nearly all of the species that are expected to occur in the 
MITT Study Area. The photographic catalogs have progressively grown to 
the point that abundance analyses may be attempted for the most 
commonly-encountered species. Beyond occurrence, questions related to 
exposure to Navy training have been addressed, such as utilizing 
satellite tag telemetry to evaluate overlap of habitat use with 
underwater detonation training sites. Also during Phase II monitoring, 
a pilot study to investigate reports of humpback whales occasionally 
occurring off Saipan has proven fruitful, yielding confirmation of this 
species there, photographic matches of individuals to other waters in 
the Pacific Ocean, as well as genetics data that provide clues as to 
the population identity of these animals (Hill et al., 2016a; Hill et 
al., 2017b). Importantly, the compiled data were also used to inform 
proposals for new mitigation areas for this rule and associated 
consultations.
    The ongoing regional species-specific study questions and results 
from recent efforts are publicly available on the Navy's Monitoring 
Program website. With basic occurrence information now well-
established, the primary goal of monitoring in the MITT Study Area 
under this rule will be to close out these studies with final analyses. 
As the collection and analysis of basic occurrence data across Navy 
ranges (including MITT) is completed, the focus of monitoring across 
all Navy range complexes will progressively move toward addressing the 
important questions of exposure and response to mid-frequency active 
sonar and other Navy training, as well as the consequences of those 
exposures, where appropriate. The Navy's hydrophone-instrumented ranges 
have proven to be a powerful tool towards this end and because of the 
lack of such an instrumented range in the MITT Study Area, monitoring 
investments are expected to begin shifting to other Navy range 
complexes as the currently ongoing research efforts in the Mariana 
Islands are completed. Any future monitoring results for the MITT Study 
Area will continue to be published on the Navy's Monitoring Program 
website, as well as discussed during annual adaptive management 
meetings between NMFS and the Navy.
    The Navy's marine species monitoring program typically supports 
several monitoring projects in the MITT Study Area at any given time. 
Additional details on the scientific objectives for each project can be 
found at https://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/. Projects can be either major multi-year efforts, or 
one to two-year special studies. The monitoring projects going into 
2020 include:
     Co-fund (with NMFS' Pacific Island Fisheries Science 
Center) the Pacific Marine Assessment Program for Protected Species 
(PACMAPPS) Mariana Islands large vessel visual and acoustic survey in 
spring-summer 2021 to help document marine mammal (including beaked 
whale) occurrence, abundance, and distribution in the Mariana Islands. 
This effort will include deployments of a towed array as well as 
floating passive acoustic buoy;
     Humpback whale visual survey at Farallon De Medinilla;
     Continued coordination with NMFS' PIFSC for small boat 
humpback

[[Page 46389]]

whale surveys at other Mariana Islands (e.g., Saipan);
     Analysis of previously deployed passive acoustic sensors 
for detection of humpback whale vocalizations at other islands (e.g., 
Pagan);
     Conduct additional occurrence surveys for beaked whales 
within the Mariana Islands beginning in fall 2021 or winter-spring 2022 
(this allows assessment of PACMAPPs beaked whale analysis to inform 
decision on deployment locations). This is a new monitoring project 
since publication of the proposed rule; and
     Funding to researchers with PIFSC for detailed necropsy 
support for select stranded marine mammals in Hawaii and the Mariana 
Islands.
    Since publication of the proposed rule, the decision has been made 
that the Navy will not be able to fund support for long-term satellite 
tag tracking of humpback whales.
    The Navy has also committed to a set of actions under the terms of 
this rule specifically to assist in improving the science on beaked 
whales (some of which will also benefit other species) and facilitate 
potential adaptive management actions (e.g., modification of mitigation 
or monitoring measures) relative to beaked whales in the MITT Study 
Area:
     Continue to fund additional stranding response/necropsy 
analyses for the Pacific Islands region. In 2018, the Navy funded the 
University of Hawaii for two years of additional necropsy support in 
the MITT Study Area and Hawaii and planned another funding cycle in 
Fiscal Year 2020. Complementing this, the Navy provided funding for 
additional stranding data analysis for all species in the MITT Study 
Area and HRC.
     Fund research on a framework to improve the analysis of 
single and mass stranding events, including the development of more 
advanced statistical methods to better characterize the uncertainty 
associated with data parameters. In addition, the Navy is exploring 
whether additional funding is available for the Center for Naval 
Analysis to research improvements to statistical analysis. As of July 
2020, the status of this request was still pending.
     Increased analysis for any future beaked whale stranding 
in the Mariana Islands to include detailed Navy review of available 
records of sonar use. In the previous regulations (2015-2020), reports 
included time and location of a stranding. For these regulations, the 
Navy will provide detailed record reviews including participating 
units/commands to gain a better idea of what sonar was used and when, 
For example in the previous regulations, the Navy's report would 
include if active sonobuoys were deployed, but not information on 
whether any active pings were transmitted.
     Monitor beaked whale occurrence within select portions of 
the MITT Study Area starting in 2022, so as to not duplicate efforts 
from item number 1 above.
     Include Cuvier's beaked whales as a priority species for 
analysis under a 2020-2023 Navy research-funded program entitled Marine 
Species Monitoring for Potential Consequences of Disturbance 
(MSM4PCOD). MSM4PCOD will explore how Navy funded monitoring priorities 
can be adjusted to provide the best scientific information supporting 
Population Consequence of Disturbance analysis. The Navy (Living Marine 
Resources Program) has already funded this program for Fiscal Years 
2018-2022 and more information is available here https://www.navfac.navy.mil/content/dam/navfac/Specialty%20Centers/Engineering%20and%20Expeditionary%20Warfare%20Center/Environmental/lmr/LMRFactSheet_Project43.pdf. The prioritization for beaked whales was 
the result of a virtual conference in May 2020. Cuvier's beaked whales 
in Southern California and Blainville's beaked whales in the Hawaii 
Range Complex have among the most robust population and exposure 
studies to date in the Pacific. Given likely similarities between 
Cuvier's beaked whales across the Pacific, this program will help 
identify the best way forward for monitoring for Cuvier's beaked whales 
in the Mariana Islands.

Adaptive Management

    The regulations governing the take of marine mammals incidental to 
Navy training and testing activities in the MITT Study Area contain an 
adaptive management component. Our understanding of the effects of Navy 
training and testing activities (e.g., acoustic and explosive 
stressors) on marine mammals continues to evolve, which makes the 
inclusion of an adaptive management component both valuable and 
necessary within the context of seven-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 to existing mitigation and 
monitoring requirements 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 will have a 
reasonable likelihood of more effectively accomplishing the goals of 
the mitigation and monitoring and if the measures are practicable. If 
the modifications to the mitigation, monitoring, or reporting measures 
are substantial, NMFS will publish a notice of the planned LOA in the 
Federal Register and solicit public comment.
    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) results from specific stranding investigations; (3) 
results from general marine mammal and sound research; and (4) 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. The results from monitoring reports and other studies 
may be viewed at https://www.navymarinespeciesmonitoring.us.
Beaked Whale Expert Panel
    As noted in the discussion of beaked whale mortality in the 
Comments and Responses section, as well as the Monitoring section 
above, both NMFS and the Navy acknowledge the need for more data and 
continuing discussion on the topic of beaked whales, mitigation, and 
monitoring. Accordingly, as recommended by public commenters, the Navy 
has agreed to fund and co-organize with NMFS an expert panel to provide 
recommendations on scientific data gaps and uncertainties for further 
protective measure consideration to minimize the impact of Navy 
training and testing activities on beaked whales in the Mariana 
Islands. Two years of additional data will be collected for beaked 
whales in the MITT Study Area prior to the expert panel meeting.

Reporting

    In order to issue incidental take authorization 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. Reports 
from individual monitoring events, results of analyses, publications, 
and periodic progress reports for specific monitoring projects

[[Page 46390]]

will be posted to the Navy's Marine Species Monitoring web portal: 
http://www.navymarinespeciesmonitoring.us.
    Currently, there are several different reporting requirements 
pursuant to the 2015-2020 regulations. All of these reporting 
requirements will continue under this rule for the seven-year period.

Notification of Injured, Live Stranded or Dead Marine Mammals

    The Navy will consult the Notification and Reporting Plan, which 
sets out notification, reporting, and other requirements when injured, 
live stranded, or dead marine mammals are detected. The Notification 
and Reporting Plan is available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.

Annual MITT Monitoring Report

    The Navy will submit an annual report to NMFS of the MITT Study 
Area monitoring which will be included in a Pacific-wide monitoring 
report including results specific to the MITT Study Area describing the 
implementation and results from the previous calendar year. Data 
collection methods will be standardized across Pacific Range Complexes 
including the MITT, HSTT, NWTT, and Gulf of Alaska (GOA) Study Areas to 
the best extent practicable, to allow for comparison in different 
geographic locations. The report must be submitted to the Director, 
Office of Protected Resources, NMFS, either within three months after 
the end of the calendar year, or within three months after the 
conclusion of the monitoring year, to be determined by the Adaptive 
Management process. NMFS will submit comments or questions on the draft 
monitoring report, if any, within three months of receipt. The report 
will be considered final after the Navy has addressed NMFS' comments, 
or three months after the submittal of the draft if NMFS does not 
provide comments on the draft report. Such a report describes progress 
of knowledge made with respect to monitoring study questions across 
multiple Navy ranges associated with the ICMP. Similar study questions 
will be treated together so that progress on each topic is summarized 
across multiple Navy ranges. The report need not include analyses and 
content that does not provide direct assessment of cumulative progress 
on the monitoring study question. This will allow the Navy to provide a 
cohesive monitoring report covering multiple ranges (as per ICMP 
goals), rather than entirely separate reports for the MITT, HSTT, NWTT, 
and GOA Study Areas.

Annual MITT Training and Testing Exercise Report

    Each year, the Navy will submit a preliminary report (Quick Look 
Report) to NMFS detailing the status of authorized sound sources within 
21 days after the anniversary of the date of issuance of the LOA. The 
Navy will also submit a detailed report (MITT Annual Training and 
Testing Exercise Report) to NMFS within three months after the one-year 
anniversary of the date of issuance of the LOA. If desired, the Navy 
may elect to consolidate the MITT Annual Training and Testing Exercise 
Report with other exercise reports from other range complexes in the 
Pacific Ocean for a single Pacific Exercise Report. NMFS will submit 
comments or questions on the report, if any, within one month of 
receipt. The report will be considered final after the Navy has 
addressed NMFS' comments, or one month after submittal of the draft if 
NMFS does not provide comments on the draft report. The annual report 
will contain information on MTEs, Sinking Exercise (SINKEX) events, and 
a summary of all sound sources used (total hours or quantity of each 
bin of sonar or other non-impulsive source; total annual number of each 
type of explosive exercises; and total annual expended/detonated rounds 
(missiles, bombs, sonobuoys, etc.) for each explosive bin). The annual 
report will also specifically include information on sound sources used 
(i.e., total hours of operation of all active sonar (all bins, by bin)) 
used in the Marpi Reef and Chalan Kanoa Reef Geographic Mitigation 
Areas from December 1 to April 30. The annual report will also contain 
both current year's sonar and explosive use data as well as cumulative 
sonar and explosive use quantity from previous years' reports 
Additionally, if there were any changes to the sound source allowance 
in the reporting year, or cumulatively, the report will include a 
discussion of why the change was made and include analysis to support 
how the change did or did not affect the analysis in the 2020 MITT 
FSEIS/OEIS and MMPA final rule. See the regulations below for more 
detail on the content of the annual report.
    The final annual/close-out report at the conclusion of the 
authorization period (year seven) will also serve as the comprehensive 
close-out report and include both the final year annual use compared to 
annual authorization as well as a cumulative seven-year annual use 
compared to seven-year authorization. NMFS must submit comments on the 
draft close-out report, if any, within three months of receipt. The 
report will be considered final after the Navy has addressed NMFS' 
comments, or three months after the submittal of the draft if NMFS does 
not provide comments.
    Information included in the annual reports may be used to inform 
future adaptive management of activities within the MITT Study Area.
    Specific sub-reporting in these annual reports will include:
     Sonar Exercise Notification: The Navy will submit an 
electronic report to NMFS within fifteen calendar days after the 
completion of any major training exercise indicating: Location of the 
exercise; beginning and end dates of the exercise; and type of 
exercise.

Other Reporting and Coordination

    The Navy will continue to report and coordinate with NMFS for the 
following:
     Annual marine species monitoring technical review meetings 
that also include researchers and the Marine Mammal Commission 
(currently, every two years a joint Pacific-Atlantic meeting is held); 
and
     Annual Adaptive Management meetings that also include the 
Marine Mammal Commission (recently modified to occur in conjunction 
with the annual monitoring technical review meeting).

Analysis and Negligible Impact Determination

General Negligible Impact Analysis

Introduction
    NMFS has defined negligible impact 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 (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. In considering 
how Level A harassment or Level B harassment (as presented in Table 28) 
factor into the negligible impact analysis, in addition to considering 
the number of estimated takes, NMFS considers other factors, such as 
the likely nature of any responses (e.g., intensity, duration), the 
context of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely

[[Page 46391]]

effectiveness of the mitigation. We also assess the number, intensity, 
and context of estimated takes by evaluating this information relative 
to population status. Consistent with the 1989 preamble for NMFS' 
implementing regulations (54 FR 40338; September 29, 1989), the impacts 
from other past and ongoing anthropogenic activities are incorporated 
into this analysis via their impacts on the baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known).
    In the Estimated Take of Marine Mammals section, we identified the 
subset of potential effects that are expected to rise to the level of 
takes both annually and over the seven-year period covered by this 
rule, and then identified the maximum number of harassment takes that 
are reasonably expected to occur based on the methods described. The 
impact that any given take will have on an individual, and ultimately 
the species or stock, is dependent on many case-specific factors that 
need to be considered in the negligible impact analysis (e.g., the 
context of behavioral exposures such as duration or intensity of a 
disturbance, the health of impacted animals, the status of a species 
that incurs fitness-level impacts to individuals, etc.). For this rule 
we evaluated the likely impacts of the enumerated maximum number of 
harassment takes reasonably expected to occur, and also authorized, in 
the context of the specific circumstances surrounding these predicted 
takes. Last, we collectively evaluated this information, as well as 
other more taxa-specific information and mitigation measure 
effectiveness, in group-specific assessments that support our 
negligible impact conclusions for each species. Because the marine 
mammal populations in the MITT Study Area have not been assigned to 
stocks, all negligible impact analysis and determinations are at the 
species level.
    As explained in the Estimated Take of Marine Mammals section, no 
take by serious injury or mortality is authorized or anticipated to 
occur.
    The Specified Activities reflect representative levels of training 
and testing activities. The Description of the Specified Activity 
section describes annual activities. There may be some flexibility in 
the exact number of hours, items, or detonations that may vary from 
year to year, but take totals will not exceed the seven-year totals 
indicated in Table 28. We base our analysis and negligible impact 
determination on the maximum number of takes that are reasonably 
expected to occur and are authorized, although, as stated before, the 
number of takes are only a part of the analysis, which includes 
extensive qualitative consideration of other contextual factors that 
influence the degree of impact of the takes on the affected 
individuals. To avoid repetition, we provide some general analysis in 
this General Negligible Impact Analysis section that applies to all the 
species listed in Table 28, given that some of the anticipated effects 
of the Navy's training and testing activities on marine mammals are 
expected to be relatively similar in nature. Then, in the Group and 
Species-Specific Analyses section, we subdivide into discussions of 
Mysticetes and Odontocetes, as there are broad life history traits that 
support an overarching discussion of some factors considered within the 
analysis for those groups (e.g., high-level differences in feeding 
strategies). Last, 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 of that 
species 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 species. Organizing our analysis by grouping species that share 
common traits or that will respond similarly to effects of the Navy's 
activities and then providing species-specific information allows us to 
avoid duplication while assuring that we have analyzed the effects of 
the specified activities on each affected species.
Harassment
    The Navy's harassment take request is based on its model, as well 
as the quantitative assessment of mitigation, which NMFS reviewed and 
concurs appropriately predict the maximum amount of harassment that is 
likely to occur. The model calculates sound energy propagation from 
sonar, 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 energy received by a marine 
mammal exceeds the thresholds for effects. Assumptions in the Navy 
model intentionally err on the side of overestimation when there are 
unknowns. Naval activities are modeled as though they would occur 
regardless of proximity to marine mammals, meaning that no mitigation 
is considered (e.g., no power down or shut down) and without any 
avoidance of the activity by the animal. The final step of the 
quantitative analysis of acoustic effects, which occurs after the 
modeling, is to consider the implementation of mitigation and the 
possibility that marine mammals would avoid continued or repeated sound 
exposures. NMFS provided input to, independently reviewed, and 
concurred with the Navy on this process and the Navy's analysis, which 
is described in detail in Section 6 of the Navy's rulemaking/LOA 
application, and was used to quantify harassment takes for this rule.
    Generally speaking, 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 for behavioral 
effects throughout species, individuals, or circumstances) and less 
severe effects from takes resulting from exposure to lower received 
levels. However, there is also growing evidence of the importance of 
distance in predicting marine mammal behavioral response to sound--
i.e., sounds of a similar level emanating from a more distant source 
have been shown to be less likely to evoke a response of equal 
magnitude (DeRuiter 2012, Falcone et al. 2017). The estimated number of 
Level A harassment and Level B harassment 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 A harassment and Level B harassment threshold) that are 
anticipated to occur annually and over the seven-year period. These 
instances may represent either brief exposures (seconds or minutes) or, 
in some cases, longer durations of exposure within a day. Some 
individuals may experience multiple instances of take (meaning over 
multiple days) over the course of the year, which means that the number 
of individuals taken is smaller than the total estimated takes. 
Generally speaking, the higher the number of takes as compared to the 
population abundance, the more repeated takes of individuals are 
likely, and the higher the actual percentage of individuals in the 
population that are likely taken at least once in a year. We look at 
this comparative metric to give us a relative sense of where a larger 
portion of a species is being taken by Navy activities, where there is 
a higher likelihood that the same individuals are being taken across 
multiple days, and where that number of days might be higher or more 
likely sequential. Where the number of instances of take is 100 percent 
or less of the abundance and there is no information to specifically 
suggest that a small subset of animals will be repeatedly taken over a 
high

[[Page 46392]]

number of sequential days, the overall magnitude is generally 
considered relatively low, as it could on one extreme mean that every 
individual taken will be taken on no more than one day (a very minimal 
impact) or, more likely, that some smaller portion of individuals are 
taken on one day annually, some are taken on a few not likely 
sequential days annually, and some are not taken at all.
    In the ocean, the use of sonar and other active acoustic sources is 
often transient and is unlikely to repeatedly expose the same 
individual animals within a short period, for example within one 
specific exercise. However, for some individuals of some species 
repeated exposures across different activities could occur over the 
year, especially where events occur in generally the same area with 
more resident species. In short, for some species we expect that the 
total anticipated takes represent exposures of a smaller number of 
individuals of which some will be exposed multiple times, but based on 
the nature of the Navy activities and the movement patterns of marine 
mammals, it is unlikely that individuals from most species will be 
taken over more than a few non-sequential days. This means that even 
where repeated takes of individuals may occur, they are more likely to 
result from non-sequential exposures from different activities. As 
described elsewhere, the nature of the majority of the exposures is 
expected to be of a less severe nature and based on the numbers it is 
likely that any individual exposed multiple times is still only taken 
on a small percentage of the days of the year.
Physiological Stress Response
    Some of the lower level physiological stress responses (e.g., 
orientation or startle response, change in respiration, change in heart 
rate) discussed in the proposed rule would likely co-occur with the 
predicted harassments, although these responses are more difficult to 
detect and fewer data exist relating these responses to specific 
received levels of sound. Takes by Level B harassment, then, may have a 
stress-related physiological component as well; however, we would not 
expect the Navy's generally short-term, intermittent, and (typically in 
the case of sonar) transitory activities to create conditions of long-
term, continuous noise leading to long-term physiological stress 
responses in marine mammals that could affect reproduction or survival.
Behavioral Response
    The estimates calculated using the behavioral response function do 
not differentiate between the different types of behavioral responses 
that rise to the level of take by Level B harassment. As described in 
the Navy's application, the Navy identified (with NMFS' input) the 
types of behaviors that would be considered a take (moderate behavioral 
responses as characterized in Southall et al. (2007) (e.g., altered 
migration paths or dive profiles, interrupted nursing, breeding or 
feeding, or avoidance) that also would be expected to continue for the 
duration of an exposure). The Navy then compiled the available data 
indicating at what received levels and distances those responses have 
occurred, and used the indicated literature to build biphasic 
behavioral response curves and cutoff distances that are used to 
predict how many instances of Level B harassment by behavioral 
disturbance occur in a day. Take estimates alone do not provide 
information regarding the potential fitness or other biological 
consequences of the reactions on the affected individuals. We therefore 
consider the available activity-specific, environmental, and species-
specific information to determine the likely nature of the modeled 
behavioral responses and the potential fitness consequences for 
affected individuals.
    Use of sonar and other transducers will typically be transient and 
temporary. The majority of acoustic effects to individual animals from 
sonar and other active sound sources during testing and training 
activities will be primarily from ASW events. It is important to note 
that although ASW is one of the warfare areas of focus during MTEs, 
there are significant periods when active ASW sonars are not in use. 
Nevertheless, behavioral reactions are assumed more likely to be 
significant during MTEs than during other ASW activities due to the 
duration (i.e., multiple days), scale (i.e., multiple sonar platforms), 
and use of high-power hull-mounted sonar in the MTEs. In other words, 
in the range of potential behavioral effects that might be expected to 
be part of a response that qualifies as an instance of Level B 
harassment by behavioral disturbance (which by nature of the way it is 
modeled/counted, occurs within one day), the less severe end might 
include exposure to comparatively lower levels of a sound, at a 
detectably greater distance from the animal, for a few or several 
minutes. A less severe exposure of this nature could result in a 
behavioral response such as avoiding an area that an animal would 
otherwise have chosen to move through or feed in for some amount of 
time or breaking off one or a few feeding bouts. More severe effects 
could occur when the animal gets close enough to the source to receive 
a comparatively higher level, is exposed continuously to one source for 
a longer time, or is exposed intermittently to different sources 
throughout a day. Such effects might result in an animal having a more 
severe flight response and leaving a larger area for a day or more or 
potentially losing feeding opportunities for a day. However, such 
severe behavioral effects are expected to occur infrequently.
    To help assess this, for sonar (LFAS/MFAS/HFAS) used in the MITT 
Study Area, the Navy provided information estimating the percentage of 
animals that may be taken by Level B harassment under each behavioral 
response function that would occur within 6-dB increments (percentages 
discussed below in the Group and Species-Specific Analyses section). As 
mentioned above, all else being equal, an animal's exposure to a higher 
received level is more likely to result in a behavioral response that 
is more likely to lead to adverse effects, which could more likely 
accumulate to impacts on reproductive success or survivorship of the 
animal, but other contextual factors (such as distance) are important 
also. The majority of Level B harassment takes are expected to be in 
the form of milder responses (i.e., lower-level exposures that still 
rise to the level of take) of a generally shorter duration. We 
anticipate more severe effects from takes when animals are exposed to 
higher received levels or at closer proximity to the source. However, 
depending on the context of an exposure (e.g., depth, distance, if an 
animal is engaged in important behavior such as feeding), a behavioral 
response can vary between species and individuals within a species. 
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 smaller percentage of the anticipated Level B harassment from Navy 
activities might necessarily be expected to potentially result in more 
severe responses (see the Group and Species-Specific Analyses section 
below for more detailed information). To fully understand the likely 
impacts of the predicted/authorized take on an individual (i.e., what 
is the likelihood or degree of fitness impacts), one must look closely 
at the available contextual information,

[[Page 46393]]

such as the duration of likely exposures and the likely severity of the 
exposures (e.g., whether they will occur for a longer duration over 
sequential days or the comparative sound level that will be received). 
Ellison et al. (2012) and Moore and Barlow (2013), among others, 
emphasize the importance of context (e.g., behavioral state of the 
animals, distance from the sound source) in evaluating behavioral 
responses of marine mammals to acoustic sources.
Diel Cycle
    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). Henderson et al. (2016) found 
that ongoing smaller scale events had little to no impact on foraging 
dives for Blainville's beaked whale, while multi-day training events 
may decrease foraging behavior for Blainville's beaked whale (Manzano-
Roth et al., 2016). 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 an at-sea exercise 
lasts for multiple days does not necessarily mean that individual 
animals are 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 such as ASW 
activities, typically include vessels that are continuously moving at 
speeds typically 10-15 kn, or higher, and likely cover large areas that 
are relatively far from shore (typically more than 3 nmi from shore) 
and in waters greater than 600 ft deep. Additionally marine mammals are 
moving as well, which will make it unlikely that the same animal could 
remain in the immediate vicinity of the ship for the entire duration of 
the exercise. Further, 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 unlikely for the majority of takes. However, it is also 
worth noting that the Navy conducts many different types of noise-
producing activities over the course of the year and it is likely that 
some marine mammals will be exposed to more than one and taken on 
multiple days, even if they are not sequential.
    That said, the MITT Study Area is different than other Navy ranges 
where there can be a significant number of Navy surface ships with 
hull-mounted sonar homeported. In the MITT Study Area, there are no 
homeported surface ships with hull-mounted sonars permanently assigned. 
There is no local unit level training in the MITT Study Area for 
homeported ships such as the case for other ranges. Instead, Navy 
activities from visiting and transiting vessels are much more episodic 
in the MITT Study Area. Therefore, there could be long gaps between 
activities (i.e., weeks, months) in the MITT Study Area.
    Durations of Navy activities utilizing tactical sonar sources and 
explosives vary and are fully described in Appendix A (Training and 
Testing Activity Descriptions) of the 2020 MITT FSEIS/OEIS. Sonar used 
during ASW will impart the greatest amount of acoustic energy of any 
category of sonar and other transducers analyzed in the Navy's 
rulemaking/LOA application and include hull-mounted, towed, line array, 
sonobuoy, helicopter dipping, and torpedo sonars. Most ASW sonars are 
MFAS (1-10 kHz); however, some sources may use higher or lower 
frequencies. ASW training activities using hull-mounted sonar planned 
for the MITT Study Area generally last for only a few hours (see Table 
3). Some ASW training and testing can generally last for 2-10 days, or 
a 10-day exercise is typical for an MTE-Large Integrated ASW (see Table 
3). For these multi-day exercises there will typically be extended 
intervals of non-activity in between active sonar periods. Because of 
the need to train in a large variety of situations, the Navy does not 
typically conduct successive ASW exercises in the same locations. Given 
the average length of ASW exercises (times of sonar use) and typical 
vessel speed, combined with the fact that the majority of the cetaceans 
would not likely remain in proximity to the sound source, it is 
unlikely that an animal would be exposed to LFAS/MFAS/HFAS at levels or 
durations 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 events are scheduled to occur over a short 
duration (1-8 hours); however, the explosive component of the activity 
only lasts for minutes (see Table 3). 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, or demonstrate 
sustained behavioral responses. Although SINKEXs may last for up to 48 
hrs (4-8 hrs, possibly 1-2 days), they are almost always completed in a 
single day and only one event is planned annually for the MITT training 
activities. They are stationary and conducted in deep, open water where 
fewer marine mammals would typically be expected to be encountered. 
They also have shutdown procedures and rigorous monitoring, i.e., 
during the activity, the Navy conducts passive acoustic monitoring and 
visually observes for marine mammals 90 min prior to the first firing, 
during the event, and 2 hrs after sinking the vessel. All of these 
factors make it unlikely that individuals would be exposed to the 
exercise for extended periods or on consecutive days.
Assessing the Number of Individuals Taken and the Likelihood of 
Repeated Takes
    As described previously, Navy modeling uses the best available 
science to predict the instances of exposure above certain acoustic 
thresholds, which are equated, as appropriate, to harassment takes 
(and, for PTS, further corrected to account for mitigation and 
avoidance). As further noted, for active acoustics it is more 
challenging to parse out the number of individuals taken by Level B 
harassment and the number of times those individuals are taken from 
this larger number of instances. One method that NMFS can use to help 
better understand the overall scope of the impacts is to compare these 
total instances of take against the abundance of that species (or stock 
if applicable). For example, if there are 100 estimated harassment 
takes in a population of 100, one can assume either that every 
individual will be exposed above acoustic thresholds in no more than 
one day, or that some smaller number will be exposed in one day but a 
few individuals will be exposed multiple days within a year and a few 
not exposed at all. Where the number of instances of take exceed the 
abundance of the population (i.e., are over 100 percent), multiple 
takes of some individuals are predicted and expected to occur within a 
year. Generally

[[Page 46394]]

speaking, the higher the number of takes as compared to the population 
abundance, the more multiple takes of individuals are likely, and the 
higher the actual percentage of individuals in the population that are 
likely taken at least once in a year. We look at this comparative 
metric to give us a relative sense of where larger portions of the 
species or stocks are being taken by Navy activities and where there is 
a higher likelihood that the same individuals may be taken across 
multiple days and where that number of days might be higher. It also 
provides a relative picture of the scale of impacts to each species.
    In the ocean, unlike a modeling simulation with static animals, the 
use of sonar and other active acoustic sources is often transient, and 
is unlikely to repeatedly expose the same individual animals within a 
short period, for example within one specific exercise. However, some 
repeated exposures across different activities could occur over the 
year with more resident species. Nonetheless, the episodic nature of 
Navy activities in the MITT Study Area would mean less frequent 
exposures as compared to some other ranges. While select offshore areas 
in the MITT Study Area are used more frequently for ASW and other 
activities, these are generally further offshore than where most island 
associated resident populations would occur and instead would be in 
areas with more transitory species. In short, we expect that the total 
anticipated takes represent exposures of a smaller number of 
individuals of which some could be exposed multiple times, but based on 
the nature of the Navy's activities and the movement patterns of marine 
mammals, it is unlikely that any particular subset would be taken over 
more than a few non-sequential days.
    In using the relationship between predicted instances of take and 
the population abundance to help estimate the proportion of a 
population likely taken and the number of days over which some 
individuals may be taken, it is important to choose an appropriate 
population estimate against which to make the comparison. The SARs, 
where available, provide the official population estimate for a given 
species or stock in U.S. waters in a given year (and are typically 
based solely on the most recent survey data). When the stock is known 
to range outside of U.S. EEZ boundaries, population estimates based on 
surveys conducted only within the U.S. EEZ are known to be 
underestimates. The marine mammal populations in the MITT Study Area 
have not been assigned to specific stocks and there are no associated 
SARs. There is also no information on trends for any of these species. 
Nonetheless, the information used to estimate take included the best 
available survey abundance data to model density layers. Further, in 
calculating the percentage of takes versus abundance for each species 
in order to assist in understanding both the percentage of the species 
affected, as well as how many days across a year individuals could be 
taken, we used the data most appropriate for the situation. The survey 
data used to calculate abundance in the MITT Study Area is described in 
the report Navy Marine Species Density Database Phase III for the 
Mariana Islands Training and Testing Study Area (Navy 2018).
Temporary Threshold Shift
    NMFS and the Navy have estimated that all species of marine mammals 
may sustain some level of TTS from active sonar. As discussed in the 
proposed rule in the Potential Effects of Specified Activities on 
Marine Mammals and Their Habitat, in general, 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. Tables 49-53 indicate the number of takes by TTS that may be 
incurred by different species from exposure to active sonar and 
explosives. 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 Navy's MF sources, which are the highest power and most 
numerous sources and the ones that cause the most take, utilize the 1-
10 kHz frequency band, which suggests that if TTS were to be induced by 
any of these MF sources it would be in a frequency band somewhere 
between approximately 2 and 20 kHz, which is in the range of 
communication calls for many odontocetes, but below the range of the 
echolocation signals used for foraging. 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 
10 and 100 kHz, which means that TTS could range up to 200 kHz), which 
could overlap with the range in which some odontocetes communicate or 
echolocate. However, HF systems are typically used less frequently and 
for shorter time periods than surface ship and aircraft MF systems, so 
TTS from these sources is unlikely. There are fewer LF sources and the 
majority are used in the more readily mitigated testing environment, 
but TTS from LF sources would most likely occur below 2 kHz, which is 
in the range where many mysticetes communicate and also where other 
non-communication auditory cues are located (waves, snapping shrimp, 
fish prey). Also of note, the majority of sonar sources from which TTS 
may be incurred occupy a narrow frequency band, which means that the 
TTS incurred would also be across a narrower band (i.e., not affecting 
the majority of an animal's hearing range). This frequency provides 
information about the cues to which a marine mammal may be temporarily 
less sensitive, but not the degree or duration of sensitivity loss. TTS 
from explosives would be broadband.
    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 rule. 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 kn) and the relative motion between the sonar 
vessel and the animal. In the TTS studies discussed in the Potential 
Effects of Specified Activities on Marine Mammals and Their Habitat 
section of the proposed rule, 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, since any hull-mounted sonar, 
such as the SQS-53, engaged in anti-submarine warfare training would be 
moving at between 10 and 15 knots and nominally pinging every 50 
seconds, the vessel will have traveled a minimum distance of 
approximately 257 m during the time between those pings and, therefore, 
incurring those levels of TTS is highly unlikely. A scenario could 
occur where an animal does not leave the vicinity of a ship or travels 
a course parallel to the ship, however, the close distances

[[Page 46395]]

required make TTS exposure unlikely. For a Navy vessel moving at a 
nominal 10 knots, it is unlikely a marine mammal could maintain speed 
parallel to the ship and receive adequate energy over successive pings 
to suffer TTS.
    In short, given the anticipated duration and levels of sound 
exposure, we would not expect marine mammals to incur more than 
relatively low levels of TTS (i.e., single digits of sensitivity loss). 
To add context to this degree of TTS, individual marine mammals may 
regularly experience variations of 6 dB differences in hearing 
sensitivity across time (Finneran et al., 2000, 2002; Schlundt et al., 
2000).
    3. Duration of TTS (recovery time)--In the TTS laboratory studies 
(as discussed in the Potential Effects of Specified Activities on 
Marine Mammals and Their Habitat section of the proposed rule), 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 LFAS/MFAS/HFAS training and testing exercises in the MITT 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 hours--and any incident of TTS would likely be far less severe due 
to the short duration of the majority of the events and the speed of a 
typical vessel, especially given the fact that the higher power sources 
resulting in TTS are predominantly intermittent, which have been shown 
to result in shorter durations of TTS. Also, for the same reasons 
discussed in the Analysis and Negligible Impact Determination--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 would not usually span the entire 
frequency range of one vocalization type, much less span all types of 
vocalizations or other critical auditory cues for any given species.
    Tables 47-51 indicate the number of incidental takes by TTS for 
each species that are likely to result from the Navy's activities. As a 
general point, the majority of these TTS takes are the result of 
exposure to hull-mounted MFAS (MF narrower band sources), with fewer 
from explosives (broad-band lower frequency sources), and even fewer 
from LFAS or HFAS sources (narrower band). As described above, we 
expect the majority of these takes to be in the form of mild (single-
digit), short-term (minutes to hours), narrower band (only affecting a 
portion of the animal's hearing range) TTS. This means that for one to 
several times per year, for several minutes to maybe a few hours (high 
end) each, a taken individual will have slightly diminished hearing 
sensitivity (slightly more than natural variation, but nowhere near 
total deafness). More often than not, such an exposure would occur 
within a narrower mid- to higher frequency band that may overlap part 
(but not all) of a communication, echolocation, or predator range, but 
sometimes across a lower or broader bandwidth. The significance of TTS 
is also related to the auditory cues that are germane within the time 
period that the animal incurs the TTS. For example, if an odontocete 
has TTS at echolocation frequencies, but incurs it at night when it is 
resting and not feeding, for example, it is not impactful. In short, 
the expected results of any one of these small number of mild TTS 
occurrences could be that (1) it does not overlap signals that are 
pertinent to that animal in the given time period, (2) it overlaps 
parts of signals that are important to the animal, but not in a manner 
that impairs interpretation, or (3) it reduces detectability of an 
important signal to a small degree for a short amount of time--in which 
case the animal may be aware and be able to compensate (but there may 
be slight energetic cost), or the animal may have some reduced 
opportunities (e.g., to detect prey) or reduced capabilities to react 
with maximum effectiveness (e.g., to detect a predator or navigate 
optimally). However, given the small number of times that any 
individual might incur TTS, the low degree of TTS and the short 
anticipated duration, and the low likelihood that one of these 
instances would occur in a time period in which the specific TTS 
overlapped the entirety of a critical signal, it is unlikely that TTS 
of the nature expected to result from the Navy activities would result 
in behavioral changes or other impacts that would impact any 
individual's (of any hearing sensitivity) reproduction or survival.
Auditory Masking or Communication Impairment
    The ultimate potential impacts of masking on an individual (if it 
were to occur) are similar to those discussed for TTS, but an important 
difference is that masking only occurs during the time of the signal, 
versus TTS, which continues beyond the duration of the signal. 
Fundamentally, masking is referred to as a chronic effect because one 
of the key potential harmful components of masking is its duration--the 
fact that an animal would have reduced ability to hear or interpret 
critical cues becomes much more likely to cause a problem the longer it 
is occurring. Also inherent in the concept of masking is the fact that 
the potential for the effect is only present during the times that the 
animal and the source are in close enough proximity for the effect to 
occur (and further, this time period would need to coincide with a time 
that the animal was utilizing sounds at the masked frequency). As our 
analysis has indicated, because of the relative movement of vessels and 
the sound sources primarily involved in this rule, we do not expect the 
exposures with the potential for masking to be of a long duration. 
Masking is fundamentally more of a concern at lower frequencies, 
because low frequency signals propagate significantly further than 
higher frequencies and because they are more likely to overlap both the 
narrower LF calls of mysticetes, as well as many non-communication cues 
such as fish and invertebrate prey, and geologic sounds that inform 
navigation. It should be noted that the Navy is only proposing 
authorization for a small subset of more narrow frequency LF sources 
and for less than 11 hours cumulatively annually. Masking is also more 
of a concern from continuous sources (versus intermittent sonar 
signals) where there is no quiet time between pulses within which 
auditory signals can be detected and interpreted. For these reasons, 
dense aggregations of, and long exposure to, continuous LF activity are 
much more of a concern for masking, whereas comparatively short-term 
exposure to the predominantly intermittent pulses of often narrow 
frequency range MFAS or HFAS, or explosions are not expected to result 
in a meaningful amount of masking. While the Navy occasionally uses LF 
and more continuous sources, it is not in the contemporaneous aggregate 
amounts that would accrue to a masking concern. Specifically, the 
nature of the activities and sound sources used by the Navy do

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not support the likelihood of a level of masking accruing that would 
have the potential to affect reproductive success or survival. 
Additional detail is provided below.
    Standard hull-mounted MFAS typically pings every 50 seconds. Some 
hull-mounted anti-submarine sonars can also be used in an object 
detection mode known as ``Kingfisher'' mode (e.g., used on vessels when 
transiting to and from port) where pulse length is shorter but pings 
are much closer together in both time and space since the vessel goes 
slower when operating in this mode. Kingfisher mode is typically 
operated for relatively shorter durations. For the majority of other 
sources, the pulse length is significantly shorter than hull-mounted 
active sonar, on the order of several microseconds to tens of 
milliseconds. Some of the vocalizations that many marine mammals make 
are less than one second long, so, for example with hull-mounted sonar, 
there would be a 1 in 50 chance (only if the source was in close enough 
proximity for the sound to exceed the signal that is being detected) 
that a single vocalization might be masked by a ping. However, when 
vocalizations (or series of vocalizations) are longer than the one-
second pulse of hull-mounted sonar, or when the pulses are only several 
microseconds long, the majority of most animals' vocalizations would 
not be masked.
    Most ASW sonars and countermeasures use MF frequencies and a few 
use LF and HF frequencies. Most of these sonar signals are limited in 
the temporal, frequency, and spatial domains. The duration of most 
individual sounds is short, lasting up to a few seconds each. A few 
systems operate with higher duty cycles or nearly continuously, but 
they typically use lower power, which means that an animal would have 
to be closer, or in the vicinity for a longer time, to be masked to the 
same degree as by a higher level source. Nevertheless, masking could 
occasionally occur at closer ranges to these high-duty cycle and 
continuous active sonar systems, but as described previously, it would 
be expected to be of a short duration when the source and animal are in 
close proximity. While data are limited on behavioral responses of 
marine mammals to continuously active sonars, mysticete species are 
known to be able to habituate to novel and continuous sounds (Nowacek 
et al., 2004), suggesting that they are likely to have similar 
responses to high-duty cycle sonars. Furthermore, most of these systems 
are hull-mounted on surface ships and ships are moving at least 10 kn, 
and it is unlikely that the ship and the marine mammal would continue 
to move in the same direction and the marine mammal subjected to the 
same exposure due to that movement. Most ASW activities are 
geographically dispersed and last for only a few hours, often with 
intermittent sonar use even within this period. Most ASW sonars also 
have a narrow frequency band (typically less than one-third octave). 
These factors reduce the likelihood of sources causing significant 
masking. HF signals (above 10 kHz) attenuate more rapidly in the water 
due to absorption than do lower frequency signals, thus producing only 
a very small zone of potential masking. If masking or communication 
impairment were to occur briefly, it would more likely be in the 
frequency range of MFAS (the more powerful source), which overlaps with 
some odontocete vocalizations (but few mysticete 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 resemble the characteristics of any single 
marine mammal species' vocalizations.
    Other sources used in Navy training and testing that are not 
explicitly addressed above, many of either higher frequencies (meaning 
that the sounds generated attenuate even closer to the source) or lower 
amounts of operation, are similarly not expected to result in masking. 
For the reasons described here, any limited masking that could 
potentially occur would be minor and short-term.
    In conclusion, masking is more likely to occur in the presence of 
broadband, relatively continuous noise sources such as from vessels, 
however, the duration of temporal and spatial overlap with any 
individual animal and the spatially separated sources that the Navy 
uses would not be expected to result in more than short-term, low 
impact masking that would not affect reproduction or survival.
Injury (Permanent Threshold Shift)
    Tables 47 through 51 indicate the number of individuals of each 
species for which Level A harassment in the form of PTS resulting from 
exposure to active sonar and/or explosives is estimated to occur. The 
number of individuals to potentially incur PTS annually (from sonar and 
explosives) for each species ranges from 0 to 50 (50 is for Dwarf sperm 
whale), but is more typically 0 or 1. As described previously, no 
species are expected to incur tissue damage from explosives.
    Data suggest that many marine mammals will 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-emitting vessel at a close distance, NMFS 
has determined that the mitigation measures (i.e., shutdown/powerdown 
zones for active sonar) 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 ASW exercises, passive acoustic detections are used 
as a cue for Lookouts' visual observations when passive acoustic assets 
are already participating in an activity) in addition to Lookouts on 
vessels to detect marine mammals for mitigation implementation. As 
discussed previously, these Level A harassment take numbers represent 
the maximum number of instances in which marine mammals would be 
reasonably expected to incur PTS, and we have analyzed them 
accordingly.
    If a marine mammal is able to approach a surface vessel within the 
distance necessary to incur PTS in spite of the mitigation measures, 
the likely speed of the vessel (nominally 10-15 kn) and relative motion 
of the vessel 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 discussed previously 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. The majority of any PTS incurred as a 
result of exposure to Navy sources would be expected to be in the 2-20 
kHz range (resulting from the most powerful hull-mounted sonar) and 
could overlap a small portion of the communication frequency range of 
many odontocetes, whereas other marine mammal groups have communication 
calls at lower frequencies. Regardless of the frequency band though, 
the more important point in this case is that any PTS accrued as a 
result of exposure to Navy activities would be expected to be of a 
small amount (single digits). Permanent loss of some degree of hearing 
is a normal occurrence for older animals, and many animals are able to 
compensate for the shift, both in old age or at younger ages as the 
result of stressor exposure. While a small loss of hearing sensitivity 
may

[[Page 46397]]

include some degree of energetic costs for compensating or may mean 
some small loss of opportunities or detection capabilities, at the 
expected scale it would be unlikely to impact behaviors, opportunities, 
or detection capabilities to a degree that would interfere with 
reproductive success or survival.

Group and Species-Specific Analyses

    In this section, we build on the general analysis that applies to 
all marine mammals in the MITT Study Area and Transit Corridor from the 
previous section, and include first information and analysis that 
applies to mysticetes or, separately, odontocetes, and then within 
those two sections, more specific information that applies to smaller 
groups, where applicable, and the affected species. The specific 
authorized take numbers are also included in the analyses below, and so 
here we provide some additional context and discussion regarding how we 
consider the authorized take numbers in those analyses.
    The maximum amount and type of incidental take of marine mammals 
reasonably likely to occur from exposures to sonar and other active 
acoustic sources and explosions and therefore authorized during the 
seven-year training and testing period are shown in Table 28. The vast 
majority of predicted exposures (greater than 99 percent) are expected 
to be Level B harassment (TTS and behavioral reactions) from acoustic 
and explosive sources during training and testing activities at 
relatively low received levels.
    In the discussions below, the estimated takes by Level B harassment 
represent instances of take, not the number of individuals taken (the 
much lower and less frequent takes by Level A harassment are far more 
likely to be associated with separate individuals), and in some cases 
individuals may be taken more than one time. Below, we compare the 
total take numbers (including PTS, TTS, and behavioral disturbance) for 
species to their associated abundance estimates to evaluate the 
magnitude of impacts across the species and to individuals. Generally, 
when an abundance percentage comparison is below 100, it suggests the 
following: (1) That not all of the individuals will be taken; (2) that, 
barring specific circumstances suggesting repeated takes of individuals 
(such as in circumstances where all activities resulting in take are 
focused in one area and time where the same individual marine mammals 
are known to congregate, such as pinnipeds at a pupping beach), the 
average or expected number of days taken for those individuals taken is 
one per year; and (3) that we would not expect any individuals to be 
taken more than a few times in a year, or for those days to be 
sequential. There are no cases in this rule where the percentage of 
takes as compared to abundance is greater than 100, the highest being 
93 percent (for fin whales) and the remaining species at 55 percent or 
less (most are 20 percent or under).
    To assist in understanding what this analysis means, we clarify a 
few issues related to estimated takes and the analysis here. An 
individual that incurs a PTS or TTS take may sometimes, for example, 
also be subject to behavioral disturbance at the same time. As 
described above in this section, the degree of PTS, and the degree and 
duration of TTS, expected to be incurred from the Navy's activities are 
not expected to impact marine mammals such that their reproduction or 
survival could be affected. Similarly, data do not suggest that a 
single instance in which an animal incurs PTS or TTS and is also 
subject to behavioral disturbance would result in impacts to 
reproduction or survival. Alternately, we recognize that if an 
individual is subjected to behavioral disturbance repeatedly for a 
longer duration and on consecutive days, effects could accrue to the 
point that reproductive success is jeopardized, although those sorts of 
impacts are not expected to result from these activities. Accordingly, 
in analyzing the number of takes and the likelihood of repeated and 
sequential takes, we consider the total takes, not just the Level B 
harassment takes by behavioral disruption, so that individuals 
potentially exposed to both threshold shift and behavioral disruption 
are appropriately considered. The number of Level A harassment takes by 
PTS are so low (and zero in most cases) compared to abundance numbers 
that it is considered highly unlikely that any individual would be 
taken at those levels more than once.
    Use of sonar and other transducers will typically be transient and 
temporary. The majority of acoustic effects to mysticetes from sonar 
and other active sound sources during testing and training activities 
will be primarily from ASW events. It is important to note that 
although ASW is one of the warfare areas of focus during MTEs, there 
are significant periods when active ASW sonars are not in use. 
Nevertheless, behavioral reactions are assumed more likely to be 
significant during MTEs than during other ASW activities due to the 
duration (i.e., multiple days) and scale (i.e., multiple sonar 
platforms) of the MTEs. On the less severe end, exposure to 
comparatively lower levels of sound at a detectably greater distance 
from the animal, for a few or several minutes, could result in a 
behavioral response such as avoiding an area that an animal would 
otherwise have moved through or fed in, or breaking off one or a few 
feeding bouts. More severe behavioral effects could occur when an 
animal gets close enough to the source to receive a comparatively 
higher level of sound, is exposed continuously to one source for a 
longer time, or is exposed intermittently to different sources 
throughout a day. Such effects might result in an animal having a more 
severe flight response and leaving a larger area for a day or more, or 
potentially losing feeding opportunities for a day. However, such 
severe behavioral effects are expected to occur infrequently.
    Occasional, milder behavioral reactions are unlikely to cause long-
term consequences for individual animals or populations, and even if 
some smaller subset of the takes are in the form of a longer (several 
hours or a day) and more severe responses, if they are not expected to 
be repeated over sequential days, impacts to individual fitness are not 
anticipated. Nearly all studies and experts agree that infrequent 
exposures of a single day or less are unlikely to impact an 
individual's overall energy budget (Farmer et al., 2018; Harris et al., 
2017; King et al., 2015; NAS 2017; New et al., 2014; Southall et al., 
2007; Villegas-Amtmann et al., 2015).
    If impacts to individuals are of a magnitude or severity such that 
either repeated and sequential higher severity impacts occur (the 
probability of this goes up for an individual the higher total number 
of takes it has) or the total number of moderate to more severe impacts 
occurs across sequential days, then it becomes more likely that the 
aggregate effects could potentially interfere with feeding enough to 
reduce energy budgets in a manner that could impact reproductive 
success via longer cow-calf intervals, terminated pregnancies, or calf 
mortality. It is important to note that if these impacts occurred they 
would only accrue to females, which only comprise a portion of the 
population (typically approximately 50 percent). Based on energetic 
models, it takes energetic impacts of a significantly greater magnitude 
to cause the death of an adult marine mammal, and females will always 
terminate a pregnancy or stop lactating before allowing their health to 
deteriorate. Also, the death of an adult female has significantly more 
impact on population growth rates than reductions

[[Page 46398]]

in reproductive success, while the death of an adult male has very 
little effect on population growth rates. However, as will be explained 
further in the sections below, the severity and magnitude of takes 
expected to result from the MITT activities are such that energetic 
impacts of a scale that might affect reproductive success are not 
expected to occur at all.
    The analyses below in some cases address species collectively if 
they occupy the same functional hearing group (i.e., low, mid, and 
high-frequency cetaceans), share similar life history strategies, and/
or are known to behaviorally respond similarly to acoustic stressors. 
Because some of these groups or species share characteristics that 
inform the impact analysis similarly, it would be duplicative to repeat 
the same analysis for each species. In addition, similar species 
typically have the same hearing capabilities and behaviorally respond 
in the same manner.
    Thus, our analysis below considers the effects of the Navy's 
activities on each affected species even where discussion is organized 
by functional hearing group and/or information is evaluated at the 
group level. Where there are meaningful differences between species 
that would further differentiate the analysis, they are either 
described within the section or the discussion for those species is 
included as a separate subsection. Specifically below, we first give 
broad descriptions of the mysticete and odontocete groups and then 
differentiate into further groups and species as appropriate.
Mysticetes
    This section builds on the broader discussion above and brings 
together the discussion of the different types and amounts of take that 
different species are likely to incur, the applicable mitigation, and 
the status of the species to support the negligible impact 
determinations for each species. We have described (above in the 
General Negligible Impact Analysis section) the unlikelihood of any 
masking having effects that would impact the reproduction or survival 
of any of the individual marine mammals affected by the Navy's 
activities. We also described in the Potential Effects of Specified 
Activities on Marine Mammals and Their Habitat section of the proposed 
rule the unlikelihood of any habitat impacts having effects that would 
impact the reproduction or survival of any of the individual marine 
mammals affected by the Navy's activities. No new information has been 
received that affects that analysis and conclusion. There is no 
predicted tissue damage from explosives for any species, and one 
mother-calf pair of humpback whales could be taken by PTS by sonar 
exposure over the course of the seven-year rule. Much of the discussion 
below focuses on the behavioral effects and the mitigation measures 
that reduce the probability or severity of effects. Because there are 
species-specific considerations, at the end of the section we break out 
our findings on a species-specific basis.
    In Table 47 below for mysticetes, we indicate for each species the 
total annual numbers of take by Level A and Level B harassment, and a 
number indicating the instances of total take as a percentage of 
abundance in the MITT Study Area alone, as well as the MITT Study Area 
plus the Transit Corridor, which was calculated separately. While the 
density used to calculate take is the same for these two areas, the 
takes were calculated separately for the two areas for all species in 
this rule, not just mysticetes, because the activity levels are higher 
in the MITT Study Area and it is helpful to understand the comparative 
impacts in the two areas. Note also that for mysticetes, the abundance 
within the MITT Study Area and Transit Corridor represents only a 
portion of the species abundance.

   Table 47--Annual Estimated Takes by Level B Harassment and Level A Harassment for Mysticetes and Number Indicating the Instances of Total Take as a
                                         Percentage of Abundance Within the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Instances of indicated types of incidental take (not all         Abundance        Instances of total
                                                     takes represent separate individuals, especially for    ----------------------  take as percentage
                                                                         disturbance)                                                   of abundance
                                                -------------------------------------------------------------                      ---------------------
                                                     Level B harassment       Level A        Total takes                    MITT
                    Species                     --------------------------- harassment ----------------------    MITT      study                  MITT
                                                                           ------------               MITT      study      area +      MITT      study
                                                                                           MITT      study       area     transit     study      area +
                                                   Behavioral       TTS                   study      area +               corridor     area     transit
                                                   disturbance                  PTS        area     transit                                     corridor
                                                                                                    corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale.....................................               4         20           0         24         24        134        150         18         16
Bryde's whale..................................              40        258           0        296        298      1,470      1,596         20         19
Fin whale......................................               5         20           0         25         25         27         46         93         54
Humpback whale.................................              92        679         * 2        768        771      2,393      2,673      20 32      18 29
Minke whale....................................              10         85           0         95         95        403        450         23         21
Omura's whale..................................               4         25           0         28         29        143        160         20         18
Sei whale......................................              19        136           0        154        155        780        821         20         19
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
  Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
  Study Area = Abundance in the MITT Study. Note that the total annual takes described here may be off by a digit due to rounding. This occurred here as
  the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
  number in the Estimated Take of Marine Mammals section.
* There is one mother-calf pair of humpback whales estimated to be taken by Level A Harassment by PTS over the period of the rule. See the Estimated
  Take of Marine Mammals section for further details.

    The majority of takes by harassment of mysticetes in the MITT Study 
Area will be caused by sources from the MF1 MFAS active sonar bin 
(which includes hull-mounted sonar) because they are high level, 
narrowband sources in the 1-10 kHz range, which intersect what is 
estimated to be the most sensitive area of hearing for mysticetes. They 
also are used in a large portion of exercises (see Tables 3 and 4). 
Most of the takes (66 percent) from the MF1 bin in the MITT Study Area 
would result from received levels between 154 and 172 dB SPL, while 
another 33 percent would result from exposure between 172 and 178 dB 
SPL. For the remaining active sonar bin types, the percentages are as 
follows: LF4 = 97 percent between 124 and 136 dB SPL, MF4 = 99 percent 
between 136 and 154 dB SPL, MF5 = 98 percent between 118 and 142 dB 
SPL, and HF4 = 98 percent between 100 and 148 dB SPL. For explosives, 
no blue whales or

[[Page 46399]]

fin whales will be taken by Level B harassment or Level A harassment 
(PTS). For other mysticetes, exposure to explosives will result in 
small numbers of take: 1-6 takes by Level B harassment by behavioral 
disturbance per species, and 0-3 TTS takes per species (0 for Omura's 
whales). Based on this information, the majority of the Level B 
harassment by behavioral disturbance is expected to be of low to 
sometimes moderate severity and of a relatively shorter duration. No 
tissue damage from training and testing activities is anticipated or 
authorized for any species.
    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 feeding or breeding grounds. Behavioral reactions may include 
alerting, breaking off feeding dives and surfacing, diving or swimming 
away, or no response at all (DOD, 2017; Nowacek, 2007; Richardson, 
1995; Southall et al., 2007). Overall, mysticetes have been observed to 
be more reactive to acoustic disturbance when a noise source is located 
directly on their migration route. Mysticetes disturbed while migrating 
could pause their migration or route around the disturbance, while 
males en route to breeding grounds have been shown to be less 
responsive to disturbances. Although some may pause temporarily, they 
will resume migration shortly after the exposure ends. Animals 
disturbed while engaged in other activities such as feeding or 
reproductive behaviors may be more likely to ignore or tolerate the 
disturbance and continue their natural behavior patterns.
    Alternately, adult female mysticetes with calves may be more 
responsive to stressors. An increase in the disturbance level from 
noise-generating human activities (such as, for example, sonar or 
vessel traffic) may increase the risk of mother-calf pair separation 
(reducing the time available for suckling) or require that louder 
contact calls are made which, in turn increases the possibility of 
detection. In either case, increased ambient noise could have negative 
consequences for calf fitness (Cartwright and Sullivan 2009; Craig et 
al., 2014).
    Lactating humpback whale females mainly rest while stationary at 
shallow depths within reach of the hull of commercial ships (although 
not expected from Navy vessels for the reasons discussed in the 
proposed rule and due to the effectiveness of mitigation measures), 
increasing the potential for ship strike collisions; and even moderate 
increases of noise from vessels can decrease the communication range 
(Bejder et al., 2019). Videsen et al. (2017) reported that 
vocalizations between humpback whale mothers and calves, which included 
very weak tonal and grunting sounds, were produced more frequently 
during active dives than suckling dives, suggesting that mechanical 
stimuli rather than acoustic cues are used to initiate nursing. Their 
study suggests that the use of mechanical cues for initiating suckling 
and low level vocalizations with an active space of less than 100 m 
indicate a strong selection pressure for acoustic crypsis. Furthermore, 
such inconspicuous behavior likely reduces the risk of exposure to 
eavesdropping predators and male humpback whale escorts that may 
disrupt the high proportion of time spent nursing and resting, and 
hence ultimately compromise calf fitness. Parks et al. (2019) explored 
the potential for acoustic crypsis in North Atlantic right whale 
mother-calf pairs. Their results show that right whale mother-calf 
pairs have a strong shift in repertoire usage, significantly reducing 
the number of higher amplitude, long-distance communication signals 
they produced when compared with juvenile and pregnant whales in the 
same habitat. Similarly, Nielsen et al. (2019) concluded that acoustic 
crypsis in southern right whales and other baleen whales decreases the 
risk of alerting potential predators and hence jeopardizing a 
substantial energetic investment by the mother. These studies (i.e., 
Videsen et al., 2017; Parks et al., 2019; and Nielsen et al., 2019) 
suggest that the small active space of the weak calls between baleen 
whale mothers and calves is very sensitive to increases in ambient 
noise from human encroachment, thereby increasing the risk of mother-
calf separation.
    Few behavioral response studies have specifically looked at mother-
calf pairs; most studies have targeted adult animals. In the few 
behavioral response studies where mothers with calves were targeted, 
their responses were not different from those in groups without calves. 
For example, humpback whales in a behavioral response experiment in 
Australia responded to a 2 kHz tone stimulus by changing their course 
during migration to move more offshore and surfaced more frequently, 
but otherwise did not respond (Dunlop et al., 2013; Noad et al. 2013). 
Mother-calf pairs, either alone or with escorts, did not respond any 
differently to the tonal stimulus than groups without calves. Several 
humpback whales on breeding grounds have been observed during aerial or 
visual surveys during Navy training events involving sonar; no 
avoidance or other behavioral responses were ever noted, even when the 
whales were observed within 5 km of a vessel with active (or possibly 
active) sonar and maximum received levels were estimated to be between 
135 and 161 dB re 1 [micro]Pa (Smultea et al., 2009; Mobley et al. 
2009; Mobley and Milette 2010; Mobley 2011; Mobley and Pacini 2012; 
Mobley et al., 201; Smultea et al., 2012).
    As noted in the Potential Effects of Specified Activities on Marine 
Mammals and Their Habitat section of the proposed rule, while there are 
multiple examples from behavioral response studies of odontocetes 
ceasing their feeding dives when exposed to sonar pulses at certain 
levels, alternately blue whales (mysticetes) were less likely to show a 
visible response to sonar exposures at certain levels when feeding than 
when traveling. However, Goldbogen et al. (2013) indicated some 
horizontal displacement of deep foraging blue whales in response to 
simulated MFAS. Southall et al. (2019b) observed that after exposure to 
simulated and operational mid-frequency active sonar, more than 50 
percent of blue whales in deep-diving states responded to the sonar, 
while no behavioral response was observed in shallow-feeding blue 
whales. Southall et al. (2019b) noted that the behavioral responses 
they observed were generally brief, of low to moderate severity, and 
highly dependent on exposure context (behavioral state, source-to-whale 
horizontal range, and prey availability). Most Level B harassment by 
behavioral disturbance of mysticetes is likely to be short-term and of 
low to sometimes moderate severity, with no anticipated effect on 
reproduction or survival.
    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. Avoidance 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. Some mysticetes may avoid larger 
activities such as a MTE as they move through an area, although these 
activities do not typically use the same training locations day-after-
day during multi-day activities, except periodically in instrumented 
ranges, which do not occur within the MITT Study Area.

[[Page 46400]]

Therefore, displaced animals could return quickly after a large 
activity or MTE is completed. Due to the limited number and geographic 
scope of MTEs, it is unlikely that most mysticetes would encounter an 
MTE more than once per year and additionally, total hull-mounted sonar 
hours would be limited in several areas that are important to 
mysticetes (described below). In the ocean, the use of Navy sonar and 
other active acoustic sources is transient and is unlikely to expose 
the same population of animals repeatedly over a short period of time, 
especially given the broader-scale movements of mysticetes.
    The implementation of procedural mitigation and the sightability of 
mysticetes (especially given their large size) further reduces the 
potential for a significant behavioral reaction or a threshold shift to 
occur (i.e., shutdowns are expected to be successfully implemented), 
which is reflected in the amount and type of incidental take that is 
anticipated to occur and authorized.
    As noted previously, when an animal incurs a threshold shift, it 
occurs in the frequency from that of the source up to one octave above. 
This means that the vast majority of threshold shifts caused by Navy 
sonar sources will typically occur in the range of 2-20 kHz (from the 
1-10 kHz MF1 bin, though in a specific narrow band within this range as 
the sources are narrowband), and if resulting from hull-mounted sonar, 
will be in the range of 3.5-7 kHz. The majority of mysticete 
vocalizations occur in frequencies below 1 kHz, which means that TTS 
incurred by mysticetes will not interfere with conspecific 
communication. Additionally, many of the other critical sounds that 
serve as cues for navigation and prey (e.g., waves, fish, 
invertebrates) occur below a few kHz, which means that detection of 
these signals will not be inhibited by most threshold shift either. 
When we look in ocean areas where the Navy has been intensively 
training and testing with sonar and other active acoustic sources for 
decades, there is no data suggesting any long-term consequences to 
reproduction or survival rates of mysticetes from exposure to sonar and 
other active acoustic sources.
    All the mysticete species discussed in this section will benefit 
from the procedural mitigation measures described earlier in the 
Mitigation Measures section. Additionally, the Navy will limit 
activities and employ other measures in mitigation areas that will 
avoid or reduce impacts to humpback whales (discussed in detail below). 
Below we compile and summarize the information that supports our 
determination that the Navy's activities will not adversely affect any 
species through effects on annual rates of recruitment or survival for 
any of the affected mysticete species.
    Humpback whale--As noted in the Description of Marine Mammals and 
Their Habitat in the Area of the Specified Activities section, humpback 
whales in the Mariana Islands are considered most likely part of the 
ESA-endangered WNP DPS and the Mariana Archipelago is an established 
breeding ground. No ESA Critical Habitat has been proposed in the MITT 
Study Area. However, the areas of Marpi and Chalan Kanoa Reefs (out to 
the 400-m isobath) are known specifically to be used by mother/calf 
pairs of humpback whales (Hill et al., 2016, 2017, 2018, 2020). 
Currently, no other areas have been identified for mother/calf pairs of 
humpback whales in the Mariana Islands. The current population trend 
for the WPN DPS of humpback whales show the SPLASH abundance estimate 
for Asia represents a 6.7 percent annual rate of increase over the 1991 
to 1993 abundance estimate (Calambokidis et al., 2008). However, the 
1991 to 1993 estimate was for Ogasawara and Okinawa only, whereas the 
SPLASH estimate includes the Philippines, so the annual rate of 
increase is unknown. The population trend for WNP DPS of humpback is 
unknown (NMFS 2019).
    Regarding the consideration of how Navy activities may affect 
humpback whales in these important areas with calves, as described 
previously, this final rule includes the Chalan Kanoa Reef and Marpi 
Reef Geographic Mitigation Areas, which encompass the area of observed 
calf detections and include water depths of 400 m or less, with 
significant parts of the mitigation areas less than 200 m, which is 
where most humpback whale sightings have been made. The Navy will not 
use explosives in the Marpi Reef and Chalan Kanoa Reef Geographic 
Mitigation Areas year-round. These two geographic mitigation areas also 
will require a 20-hour annual cap (for both areas combined) from 
December 1 through April 30 on MF1 MFAS use to minimize sonar exposure 
and reduce take by Level B harassment of humpback whales in these 
important reproductive areas.
    The Navy expects current and future use of these two Geographic 
Mitigation Areas to remain low, but the 20-hour cap allows for the Navy 
to engage in a small amount of necessary training, most likely such as 
a Small Coordinated ASW Exercise or TRACKEX event(s), which could, for 
example, occur up to five days, but no more than four hours per day (or 
similar configuration totaling no more than 20 hours annually). As 
described in the Humpback Whales Around Saipan subsection of the 
Estimated Take of Marine Mammals section, our updated analysis 
indicates that given the maximum of 20 hrs of MF1 MFAS, a maximum 
annual total of 305 instances of Level B harassment may be incurred by 
61 humpback whales, including 17 calves, in these areas during these 
months in the Geographic Mitigation Areas. One mother-calf pair of 
humpback whales may be taken by Level A harassment in the form of PTS 
over the course of the seven years of activities in these areas. 
Because of the higher density of humpback whales in this area, these 
individuals could potentially be taken on up to five, most likely non-
sequential days. However, the reduction in exposure of humpback whales 
to sonar and explosive detonations in the Geographic Mitigation Areas 
and at this time (i.e., the short overall and daily exposure) will 
reduce the likelihood of impacts that could affect reproduction or 
survival, by minimizing impacts on calves during this sensitive life 
stage, avoiding the additional energetic costs to mothers of avoiding 
the area during explosive exercises, and minimizing the chances that 
important breeding behaviors are interrupted to the point that 
reproduction is inhibited or abandoned for the year, or otherwise 
interfered with. Finally, the Navy will also implement the Marpi Reef 
and Chalan Kanoa Reef Awareness Notification Message Area that will 
help alert Navy vessels operating in these areas to the possible 
presence of increased concentrations of humpback whales from December 1 
through April 30 to avoid interactions with large whales that may be 
vulnerable to vessel strikes.
    To be clear about the temporal and spatial distribution of the 
estimated take, all take of humpback whales is expected to occur from 
December through April (the months when humpback whales are located in 
the MITT Study Area), with the number noted in the previous paragraph 
occurring in the two mitigation areas, and the remainder occurring 
throughout the MITT Study Area and Transit Corridor. Regarding the 
magnitude of takes by Level B harassment (TTS and behavioral 
disruption), the number of estimated total instances of take compared 
to the abundance (measured against both the MITT Study Area abundance 
and the MITT Study Area plus the transit corridor abundance

[[Page 46401]]

combined) is 32 and 29 percent, respectively (Table 47). Regarding the 
severity of those individual takes by Level B harassment by behavioral 
disturbance, we have explained that the duration of any exposure is 
expected to be between minutes and hours (i.e., relatively short) and 
the received sound levels largely below 172 dB with a portion up to 178 
dB (i.e., of a moderate or lower level, less likely to evoke a severe 
response). While impacts to cow-calf pairs are of particular concern, 
we have also explained how the restrictions and limitations on 
explosive and sonar use in the geographic mitigation areas will 
minimize impacts. Regarding the severity of takes by TTS, they are 
expected to be low-level, of short duration, and mostly not in a 
frequency band that would be expected to interfere with communication 
or other important low-frequency cues. Therefore the associated lost 
opportunities and capabilities are not at a level that will impact 
reproduction or survival.
    Altogether, the WNP DPS of humpback whales is endangered and while 
there is not enough information to identify a population trend, the 
Mariana Archipelago has been identified as a breeding area for the WNP 
DPS of humpback whales. In consideration of the MITT Study Area as a 
whole, only a small portion of the total individuals within the MITT 
Study Area will be taken and disturbed at a low-moderate level, with 
most of those individuals likely not disturbed on more than a few non-
sequential days in a year. As described above for the mitigation areas 
specifically, if the Navy conducts the maximum five 4-hour exercises in 
these areas, cow-calf pairs could be taken on up to five likely non-
sequential days. However, takes in these mitigation areas would be as a 
result of brief exposure to one shorter-duration exercise (as discussed 
earlier, the duration of an exercise does not indicate the duration of 
exposure to the exercises, which would be significantly shorter given 
the speed of Navy vessels), and the impacts would not be expected to 
accrue to the degree that would interfere with important mother-calf 
communications in a manner leading to cow-calf separation, interfere 
with social communications in a manner that would impede breeding, or 
impact humpback cow behaviors in a manner that would have adverse 
impacts on their energy budget and lactation success. One mother-calf 
pair could be taken by a small amount of PTS over the course of these 
seven-year regulations, of likely low severity as described previously. 
A small permanent loss of hearing sensitivity (PTS) may include some 
degree of energetic costs for compensating or may mean some small loss 
of opportunities or detection capabilities for the individual. However, 
given the smaller degree of PTS, and higher frequency of the hearing 
loss anticipated to result from MF1 sonar exposure (which is above the 
frequencies used to communicate with conspecifics and, specifically, 
calves), the PTS incurred by one mother-calf pair of humpback whales in 
a given year is unlikely to impact its behaviors, opportunities, or 
detection capabilities to a degree that will interfere with 
reproductive success or survival of the individual, let alone affect 
annual rates of recruitment or survival.
    Even considering the potential impacts to cow-calf pairs, given the 
historic low use in the shallow waters of Marpi and Chalan Kanoa Reefs 
for Navy's activities as well as the restriction on explosive use and a 
20-hr cap on MFAS, as well as the low magnitude and severity of 
anticipated harassment effects, the authorized takes are not expected 
to result in impacts on the reproduction or survival of any 
individuals, let alone have impacts on annual rates of recruitment or 
survival. Therefore, the total take will not adversely affect this 
species through impacts on annual rates of recruitment or survival. No 
mortality is anticipated or authorized. For these reasons, we have 
determined, in consideration of all of the effects of the Navy's 
activities combined, that the authorized take will have a negligible 
impact on humpback whales.
    Blue whale--Blue whales are listed as endangered under the ESA 
throughout their range, with no ESA-designated critical habitat or 
known biologically important areas identified for this species in the 
MITT Study Area. There have been no stock(s) specified for the blue 
whales found in the MITT Study Area and Transit Corridor, and there is 
no associated SAR. There is also no information on trends for this 
species within the MITT Study Area. Blue whales are however considered 
stable generally throughout their range (NMFS 2019). Blue whales would 
be most likely to occur in the MITT Study Area during the winter and 
are expected to be few in number. There are no recent sighting records 
for blue whales in the MITT Study Area (Fulling et al., 2011; Hill et 
al., 2017a; Uyeyama, 2014). However, some acoustic detections from 
passive monitoring devices deployed at Saipan and Tinian have recorded 
the presence of blue whales over short periods of time (a few days) 
(Oleson et al., 2015). Since blue whale calls can travel very long 
distances (up to 621 mi (1,000 km)), it is unknown whether the animals 
were within the MITT Study Area.
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the MITT Study Area 
abundance and the MITT Study Area plus the transit corridor combined) 
is 18 and 16 percent, respectively (Table 47). Regarding the severity 
of those individual takes by Level B harassment by behavioral 
disturbance, we have explained that the duration of any exposure is 
expected to be between minutes and hours (i.e., relatively short) and 
the received sound levels largely below 172 dB with a portion up to 178 
dB (i.e., of a moderate or lower level, less likely to evoke a severe 
response). Regarding the severity of TTS takes, they are expected to be 
low-level, of short duration, and mostly not in a frequency band that 
would be expected to interfere with communication or other important 
low-frequency cues. Therefore the associated lost opportunities and 
capabilities are not at a level that will impact reproduction or 
survival.
    Altogether, blue whales are listed as endangered, there are no 
known population trends, and blue whales have a very large range and a 
low abundance in the MITT Study Area. Our analysis suggests that a 
small portion of the individuals in the MITT Study Area and Transit 
Corridor (which represent only a small portion of the total abundance 
of the species) will be taken and disturbed at a low-moderate level, 
with those individuals disturbed on likely one day within a year. No 
mortality or Level A harassment is anticipated or authorized. This low 
magnitude and severity of harassment effects is not expected to result 
in impacts on the reproduction or survival of any individuals and, 
therefore, the total take will not adversely affect this species 
through impacts on annual rates of recruitment or survival, let alone 
have impacts on annual rates of recruitment or survival. For these 
reasons, we have determined, in consideration of all of the effects of 
the Navy's activities combined, that the authorized take will have a 
negligible impact on blue whales.
    Fin whale--Fin whales are listed as endangered under the ESA 
throughout their range, with no ESA designated critical habitat or 
known biologically important areas identified for this species in the 
MITT Study Area. There have been no stock(s) specified for fin

[[Page 46402]]

whales found in the MITT Study Area and Transit Corridor, and there is 
no associated SAR. There is also no information on trends for this 
species within the MITT Study Area or in other parts of their range 
(NMFS 2019). There are no sighting records for fin whales in the MITT 
Study Area (Fulling et al., 2011; Hill et al., 2017a; Oleson et al., 
2015; Uyeyama, 2014). However, based on acoustic detections, fin whales 
are expected to be present in the MITT Study Area, although few in 
number.
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the MITT Study Area 
abundance and the MITT Study Area plus the transit corridor combined) 
is 93 and 54 percent, respectively (Table 47). Regarding the severity 
of those individual takes by Level B harassment by behavioral 
disturbance, we have explained that the duration of any exposure is 
expected to be between minutes and hours (i.e., relatively short) and 
the received sound levels largely below 172 dB with a portion up to 178 
dB (i.e., of a moderate or lower level, less likely to evoke a severe 
response). Regarding the severity of TTS takes, they are expected to be 
low-level, of short duration, and mostly not in a frequency band that 
would be expected to interfere with communication or other important 
low-frequency cues. Therefore, the associated lost opportunities and 
capabilities are not at a level that will impact reproduction or 
survival.
    Altogether, fin whales are listed as endangered, there are no known 
population trends, and they have a low abundance in the MITT Study 
Area. Our analysis suggests that up to half or more of the individuals 
in the MITT Study Area and Transit Corridor (which represent a small 
portion of the species abundance) will be taken and disturbed at a low-
moderate level, with those individuals likely not disturbed on more 
than a few non-sequential days a year. No mortality or Level A 
harassment is anticipated or authorized. This low magnitude and 
severity of harassment effects is not expected to result in impacts on 
the reproduction or survival of any individuals, let alone have impacts 
on annual rates of recruitment or survival, and therefore the total 
take will not adversely affect this species through impacts on annual 
rates of recruitment or survival. For these reasons, we have 
determined, in consideration of all of the effects of the Navy's 
activities combined, that the authorized take will have a negligible 
impact on fin whales.
    Sei whale--Sei whales are listed as endangered under the ESA 
throughout their range, with no ESA-designated critical habitat or 
known biologically important areas identified for this species in the 
MITT Study Area. There have been no stock(s) specified for sei whales 
found in the MITT Study Area and Transit Corridor, and there are no 
associated SARs. There is also no information on population trends for 
this species within the MITT Study Area or in other parts of their 
range (NMFS 2019).
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the MITT Study Area 
abundance and the MITT Study Area plus the transit corridor combined) 
is 20 and 19 percent, respectively (Table 47). Regarding the severity 
of those individual takes by Level B harassment by behavioral 
disturbance, we have explained that the duration of any exposure is 
expected to be between minutes and hours (i.e., relatively short) and 
the received sound levels largely below 172 dB with a portion up to 178 
dB (i.e., of a moderate or lower level, less likely to evoke a severe 
response). Regarding the severity of TTS takes, they are expected to be 
low-level, of short duration, and mostly not in a frequency band that 
would be expected to interfere with communication or other important 
low-frequency cues. Therefore the associated lost opportunities and 
capabilities are not at a level that will impact reproduction or 
survival.
    Altogether sei whales are listed as endangered, there are no known 
population trends. Our analysis suggests that a small portion of 
individuals within the MITT Study Area and Transit Corridor (which is a 
small portion of the species abundance) will be taken and disturbed at 
a low-moderate level, with those individuals disturbed on likely one 
day within a year. No mortality or Level A harassment is anticipated or 
authorized. This low magnitude and severity of harassment effects is 
not expected to result in impacts on the reproduction or survival of 
any individuals, let alone have impacts on annual rates of recruitment 
or survival. Therefore, the total take will not adversely affect this 
species through impacts on annual rates of recruitment or survival. For 
these reasons, we have determined, in consideration of all of the 
effects of the Navy's activities combined, that the authorized take 
will have a negligible impact on sei whales.
    Bryde's whale, Minke whale, and Omura's whale--None of these 
species of whales are listed as endangered or threatened under the ESA 
and there are no known biologically important areas identified for 
these species in the MITT Study Area. There have been no specific 
stock(s) specified for these populations found in the MITT Study Area 
and Transit Corridor, and there are no associated SARs. There is also 
no information on population trends for these species within the MITT 
Study Area.
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disturbance), the number of estimated total instances of 
take compared to the abundance (measured against both the MITT Study 
Area abundance and the MITT Study Area plus the transit corridor 
combined) is 20 and 19 percent (Bryde's whale), 23 and 21 percent 
(Minke whale), and 20 and 18 (Omura's whale) percent, respectively 
(Table 47). Regarding the severity of those individual takes by Level B 
harassment by behavioral disturbance, we have explained that the 
duration of any exposure is expected to be between minutes and hours 
(i.e., relatively short) and the received sound levels largely below 
172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, 
less likely to evoke a severe response). Regarding the severity of TTS 
takes, they are expected to be low-level, of short duration, and mostly 
not in a frequency band that would be expected to interfere with 
communication or other important low-frequency cues. Therefore, the 
associated lost opportunities and capabilities are not at a level that 
will impact reproduction or survival.
    Altogether, these three species of whales are not listed under the 
ESA and there are no known population trends. The abundance of Bryde's 
whales, minke whales, and Omura's whales in the MITT Study Area is 
thought to be low, and our analysis suggests that a small portion of 
individuals within the MITT Study Area and Transit Corridor will be 
taken and disturbed at a low-moderate level, with those individuals 
disturbed only once. No mortality or Level A harassment is anticipated 
or authorized. This low magnitude and severity of harassment effects is 
not expected to result in impacts on the reproduction or survival of 
any individuals, let alone have impacts on annual rates of recruitment 
or survival. Therefore, the total take will not adversely affect these 
species through impacts on annual rates of recruitment

[[Page 46403]]

or survival. For these reasons, we have determined, in consideration of 
all of the effects of the Navy's activities combined, that the 
authorized take will have a negligible impact on Bryde's whales, minke 
whales, and Omura's whales.
Odontocetes
    This section builds on the broader discussion above and brings 
together the discussion of the different types and amounts of take that 
different species are likely to incur, the applicable mitigation for 
each species, and the status of the species to support the negligible 
impact determinations for each species. We have described (above in the 
General Negligible Impact Analysis section) the unlikelihood of any 
masking having effects that would impact the reproduction or survival 
of any of the individual marine mammals affected by the Navy's 
activities. We also described in the Potential Effects of Specified 
Activities on Marine Mammals and Their Habitat section of the proposed 
rule the unlikelihood of any habitat impacts having effects that would 
impact the reproduction or survival of any of the individual marine 
mammals affected by the Navy's activities. No new information has been 
received that affects the analysis and conclusion. There is no 
predicted PTS from sonar or explosives for most odontocetes, with the 
exception of a few species which is discussed below. There is no 
predicted tissue damage from explosives for any species. Much of the 
discussion below focuses on the behavioral effects and the mitigation 
measures that reduce the probability or severity of effects. Here, we 
include information that applies to all of the odontocete species, 
which are then further divided and discussed in more detail in the 
following subsections: Dwarf sperm whales and pygmy sperm whales; sperm 
whales; beaked whales; and dolphins and small whales. These subsections 
include more specific information about the groups, as well as 
conclusions for each species represented.
    The majority of takes by harassment of odontocetes in the MITT 
Study Area will be caused by sources from the MFAS bin (which includes 
hull-mounted sonar) because they are high level, typically narrowband 
sources at a frequency (in the 1-10 kHz range) that overlaps a more 
sensitive portion (though not the most sensitive) of the MF hearing 
range and they are used in a large portion of exercises (see Table 3). 
For odontocetes other than beaked whales (for which these percentages 
are indicated separately in that section), most of the takes (98 
percent) from the MF1 bin in the MITT Study Area would result from 
received levels between 154 and 172 dB SPL. For the remaining active 
sonar bin types, the percentages are as follows: LF4 = 97 percent 
between 124 and 136 dB SPL, MF4 = 99 percent between 136 and 160 dB 
SPL, MF5 = 97 percent between 118 and 142 dB SPL, and HF4 = 88.6 
percent between 100 and 130 dB SPL. Based on this information, the 
majority of the takes by Level B harassment by behavioral disturbance 
are expected to be low to sometimes moderate in nature, but still of a 
generally shorter duration.
    For all odontocetes, takes from explosives (Level B harassment by 
behavioral disturbance or TTS, or PTS) comprise a very small fraction 
(and low number) of those caused by exposure to active sonar. For the 
following odontocetes, zero takes from explosives are expected to 
occur: Blainville's beaked whales, Cuvier's beaked whales, bottlenose 
dolphins, false killer whales, killer whales, sperm whales, rough-
toothed dolphins, and pygmy killer whales. For Level B harassment by 
behavioral disturbance from explosives, 1 to 4 takes are expected to 
occur for all but two of the remaining odontocetes, 25 and 64 takes for 
pygmy and dwarf sperm whales, respectively. Similarly, the instances of 
PTS and TTS from explosives are expected to be low. The instances of 
TTS expected to occur from explosives are 0 to 5 per species and the 
instances of PTS expected to occur from explosives are 0 to 1 per 
species, except for pygmy and dwarf sperm whales. Because of the lower 
TTS and PTS thresholds for HF odontocetes, pygmy and dwarf sperm whales 
are expected to have 25 and 64 takes by Level B harassment disturbance 
and 37 and 100 takes by TTS, and 8 and 21 takes by PTS from explosives, 
respectively.
    Because the majority of harassment takes of odontocetes result from 
the sources in the MFAS bin, the vast majority of threshold shift would 
occur at a single frequency within the 1-10 kHz range and, therefore, 
the vast majority of threshold shift caused by Navy sonar sources would 
be at a single frequency within the range of 2-20 kHz. The frequency 
range within which any of the anticipated narrowband threshold shift 
would occur would fall directly within the range of most odontocete 
vocalizations (2-20 kHz). For example, the most commonly used hull-
mounted sonar has a frequency around 3.5 kHz, and any associated 
threshold shift would be expected to be at around 7 kHz. However, 
individual odontocete vocalizations typically span a much wider range 
than this, and alternately, threshold shift from active sonar will 
often be in a narrower band (reflecting the narrower band source that 
caused it), which means that TTS incurred by odontocetes would 
typically only interfere with communication within a portion of their 
range (if it occurred during a time when communication with 
conspecifics was occurring) and, as discussed earlier, it would only be 
expected to be of a short duration and relatively small degree. 
Odontocete echolocation occurs predominantly at frequencies 
significantly higher than 20 kHz, though there may be some small 
overlap at the lower part of their echolocating range for some species, 
which means that there is little likelihood that threshold shift, 
either temporary or permanent would interfere with feeding behaviors. 
Many of the other critical sounds that serve as cues for navigation and 
prey (e.g., waves, fish, invertebrates) occur below a few kHz, which 
means that detection of these signals will not be inhibited by most 
threshold shift either. The low number of takes by threshold shift that 
might be incurred by individuals exposed to explosives would likely be 
lower frequency (5 kHz or less) and spanning a wider frequency range, 
which could slightly lower an individual's sensitivity to navigational 
or prey cues, or a small portion of communication calls, for several 
minutes to hours (if temporary) or permanently. There is no reason to 
think that any of the individual odontocetes taken by TTS would incur 
these types of takes over more than one day, or over a few days at 
most, and therefore they are unlikely to incur impacts on reproduction 
or survival. The number of PTS takes from these activities are very low 
(0 annually for most, 1 for a few species, and 19 and 50 for pygmy and 
dwarf sperm whales, respectively), and as discussed previously because 
of the low degree of PTS (i.e., low amount of hearing sensitivity 
loss), as well as the narrower frequency range in which the majority of 
the PTS would occur, it is unlikely to affect reproduction or survival 
of any individuals..
    The range of potential behavioral effects of sound exposure on 
marine mammals generally, and odontocetes specifically, has been 
discussed in detail previously. There are behavioral patterns that 
differentiate the likely impacts on odontocetes as compared to 
mysticetes. First, odontocetes echolocate to find prey, which means 
that they actively send out sounds to detect their prey. While there 
are many strategies for hunting, one common

[[Page 46404]]

pattern, especially for deeper diving species, is many repeated deep 
dives within a bout, and multiple bouts within a day, to find and catch 
prey. As discussed above, studies demonstrate that odontocetes may 
cease their foraging dives in response to sound exposure. If enough 
foraging interruptions occur over multiple sequential days, and the 
individual either does not take in the necessary food, or must exert 
significant effort to find necessary food elsewhere, energy budget 
deficits can occur that could potentially result in impacts to 
reproductive success, such as increased cow/calf intervals (the time 
between successive calving). Second, while many mysticetes rely on 
seasonal migratory patterns that position them in a geographic location 
at a specific time of the year to take advantage of ephemeral large 
abundances of prey (i.e., invertebrates or small fish, which they eat 
by the thousands), odontocetes forage more homogeneously on one fish or 
squid at a time. Therefore, if odontocetes are interrupted while 
feeding, it is often possible to find more prey relatively nearby.
    Dwarf Sperm Whales and Pygmy Sperm Whales (Kogia species)--This 
section builds on the broader odontocete discussion above and brings 
together the discussion of the different types and amounts of take that 
these two species are likely to incur, the applicable mitigation, and 
the status of the species to support the negligible impact 
determinations for each species. Some Level A harassment by PTS is 
anticipated annually (50 and 19 takes for Dwarf and pygmy whale, 
respectively, see Table 48).
    In Table 48 below for dwarf sperm whales and pygmy sperm whales, we 
indicate for each species the total annual numbers of take by Level A 
and Level B harassment, and a number indicating the instances of total 
take as a percentage of the abundance within the MITT Study Area alone, 
as well as the MITT Study Area plus the Transit Corridor, which was 
calculated separately. While the density used to calculate take is the 
same for these two areas, the takes were calculated separately for the 
two areas for dwarf and pygmy sperm whales because the activity levels 
are higher in the MITT Study Area and it is helpful to understand the 
comparative impacts in the two areas. Note also that for dwarf and 
pygmy sperm whales (and all odontocetes), the abundance within the MITT 
Study Area and Transit Corridor represents only a portion of the 
species abundance.

  Table 48--Annual Estimated Takes by Level B Harassment and Level A Harassment for Dwarf Sperm Whales and Pygmy Sperm Whales and Number Indicating the
                          Instances of Total Take as a Percentage of Abundance Within the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Instances of indicated types of incidental take (not all         Abundance        Instances of total
                                                     takes represent separate individuals, especially for    ----------------------  take as percentage
                                                                         disturbance)                                                   of abundance
                                                -------------------------------------------------------------                      ---------------------
                                                     Level B harassment       Level A        Total takes                    MITT
                    Species                     --------------------------- harassment ----------------------    MITT      study                  MITT
                                                                           ------------               MITT      study      area +      MITT      study
                                                                                           MITT      study       area     transit     study      area +
                                                   Behavioral       TTS                   study      area +               corridor     area     transit
                                                   disturbance                  PTS        area     transit                                     corridor
                                                                                                    corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dwarf sperm whale..............................           1,353      7,146          50      8,502      8,549     25,594     27,395         33         31
Pygmy sperm whale..............................             533      2,877          19      3,412      3,429     10,431     11,168         33         31
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
  Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
  Study Area = Abundance in the MITT Study. Note that the total annual takes described here may be off by a digit due to rounding. This occurred here as
  the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
  number in the Estimated Take of Marine Mammals section.

    As discussed above, the majority of takes by Level B harassment by 
behavioral disturbance of odontocetes, and thereby dwarf and pygmy 
sperm whales, is expected to be in the form of low to occasionally 
moderate severity of a generally shorter duration. As discussed earlier 
in this section, we anticipate more severe effects from takes when 
animals are exposed to higher received levels or for longer durations. 
Occasional milder Level B harassment by behavioral disturbance, as is 
expected here, is unlikely to cause long-term consequences for either 
individual animals or populations, even if some smaller subset of the 
takes are in the form of a longer (several hours or a day) and more 
moderate response.
    We note that dwarf and pygmy sperm whales, as HF-sensitive species, 
have a lower PTS threshold than all other groups and therefore are 
generally likely to experience larger amounts of TTS and PTS, and NMFS 
accordingly has evaluated and authorized higher numbers. Also, however, 
regarding PTS from sonar exposure, Kogia whales are still likely to 
avoid sound levels that would cause higher levels of TTS (greater than 
20 dB) or PTS. Therefore, even though the number of TTS and PTS takes 
are higher than for other odontocetes, any PTS is expected to be at a 
lower level and for all of the reasons described above, TTS and PTS 
takes are not expected to impact reproduction or survival of any 
individual.
    Neither pygmy sperm whales nor dwarf sperm whales are listed under 
the ESA, and there are no known biologically important areas identified 
for these species in the MITT Study Area and Transit Corridor. There 
have been no stock(s) specified for pygmy sperm whales and dwarf sperm 
whales found in the MITT Study Area and Transit Corridor, and there is 
no associated SAR. There is also no information on trends for these 
species within the MITT Study Area. Both pygmy and dwarf sperm whales 
will benefit from the procedural mitigation measures described earlier 
in the Mitigation Measures section.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance is 33 percent for both dwarf and pygmy sperm 
whales in the MITT Study Area and 31 percent in the MITT Study Area and 
the transit corridor combined (Table 48). Regarding the severity of 
those individual Level B harassment takes by behavioral disruption, we 
have explained that the duration of any exposure is expected to be 
between minutes and hours (i.e., relatively short) and the received 
sound levels largely below 172 dB (i.e., of a lower, to occasionally 
moderate, level

[[Page 46405]]

and less likely to evoke a severe response). Regarding the severity of 
TTS takes, they are expected to be low-level, of short duration, and 
mostly not in a frequency band that would be expected to interfere with 
dwarf or pygmy sperm whale communication or other important low-
frequency cues. Therefore, the associated lost opportunities and 
capabilities are not at a level that will impact reproduction or 
survival. Dwarf sperm whales and pygmy sperm whales could be taken by a 
small amount of PTS annually, of likely low severity as described 
previously. A small permanent loss of hearing sensitivity (PTS) may 
include some degree of energetic costs for compensating or may mean 
some small loss of opportunities or detection capabilities, but at the 
expected degree the estimated takes by Level A harassment takes by PTS 
for dwarf sperm whales and pygmy sperm whales are unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
will interfere with reproductive success or survival of any 
individuals, let alone affect annual rates of recruitment or survival.
    Altogether, dwarf and pygmy sperm whales are not listed under the 
ESA and there are no known population trends. Our analysis suggests 
that fewer than half of the individuals in the MITT Study Area and 
Transit Corridor will be taken, and disturbed at a low-moderate level, 
with those individuals likely not disturbed on more than a few non-
sequential days a year. No mortality is anticipated or authorized. The 
low magnitude and severity of harassment effects is not expected to 
result in impacts on the reproduction or survival of any individuals, 
let alone have impacts on annual rates of recruitment or survival, 
therefore, the total take will not adversely affect this species 
through impacts on annual rates of recruitment or survival. Some 
individuals are estimated to be taken by PTS of likely low severity. A 
small permanent loss of hearing sensitivity (PTS) may include some 
degree of energetic costs for compensating or may mean some small loss 
of opportunities or detection capabilities, but at the expected scale 
the estimated takes by Level A harassment by PTS are unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
would interfere with reproductive success or survival of any 
individuals, let alone affect annual rates of recruitment or survival. 
For these reasons, we have determined, in consideration of all of the 
effects of the Navy's activities combined, that the authorized take 
will have a negligible impact on both dwarf and pygmy sperm whales.
    Sperm whale--This section brings together the broader discussion 
above with the discussion of the different types and amounts of take 
that sperm whales could potentially incur, the applicable mitigation, 
and the status of the species to support the negligible impact 
determination.
    In Table 49 below for sperm whales, we indicate the total annual 
numbers of take by Level A and Level B harassment, and a number 
indicating the instances of total take as a percentage of the abundance 
within the MITT Study Area alone, as well as the MITT Study Area plus 
the Transit Corridor, which was calculated separately. While the 
density used to calculate take is the same for these two areas, the 
takes were calculated separately for the two areas for sperm whales, 
because the activity levels are higher in the MITT Study Area and it is 
helpful to understand the comparative impacts in the two areas. Note 
also that for sperm whales, the abundance within the MITT Study Area 
and Transit Corridor represents only a portion of the species 
abundance.

  Table 49--Annual Estimated Takes by Level B Harassment and Level A Harassment for Sperm Whales and Number Indicating the Instances of Total Take as a
                                         Percentage of Abundance Within the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Instances of indicated types of incidental take (not all         Abundance        Instances of total
                                                     takes represent separate individuals, especially for    ----------------------  take as percentage
                                                                         disturbance)                                                   of abundance
                                                -------------------------------------------------------------                      ---------------------
                                                     Level B harassment       Level A        Total takes                    MITT
                    Species                     --------------------------- harassment ----------------------    MITT      study                  MITT
                                                                           ------------               MITT      study      area +      MITT      study
                                                                                           MITT      study       area     transit     study      area +
                                                   Behavioral       TTS                   study      area +               corridor     area     transit
                                                   disturbance                  PTS        area     transit                                     corridor
                                                                                                    corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale....................................             192         11           0        189        203      4,216      5,146          4          4
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
  Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
  Study Area = Abundance in the MITT Study. Not that the total annual takes described here may be off by a digit due to rounding. This occurred here as
  the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
  number in the Estimated Take of Marine Mammals section.

    As discussed above, the majority of takes by Level B harassment by 
behavioral disturbance of odontocetes, and thereby sperm whales, is 
expected to be in the form of low to moderate severity of a generally 
shorter duration. As mentioned earlier in this section, we anticipate 
more severe effects from takes when animals are exposed to higher 
received levels or for longer durations. Occasional milder Level B 
harassment by behavioral disturbance, as is expected here, is unlikely 
to cause long-term consequences for either individual animals or 
populations.
    Sperm whales are listed as endangered under the ESA throughout 
their range, but there is no ESA designated critical habitat, or known 
biologically important areas identified for this species within the 
MITT Study Area. There have been no stock(s) specified for sperm whales 
found in the MITT Study Area and Transit Corridor, and there is no 
associated SAR. There is also no information on trends for this species 
within the MITT Study Area or in other parts of their range (NMFS 
2019).
    Sperm whales have been routinely sighted in the MITT Study Area and 
detected in acoustic monitoring records. Sperm whales will benefit from 
the procedural mitigation measures described earlier in the Mitigation 
Measures section.
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance is 4 percent in the MITT Study Area and 4 
percent in the MITT Study Area and transit corridor combined (Table 
49). Regarding the severity of those individual takes by Level B 
harassment by behavioral disturbance, we have explained that the

[[Page 46406]]

duration of any exposure is expected to be between minutes and hours 
(i.e., relatively short) and the received sound levels largely below 
172 dB (i.e., of a lower, to occasionally moderate level and less 
likely to evoke a severe response). Regarding the severity of TTS 
takes, they are expected to be low-level, of short duration, and mostly 
not in a frequency band that would be expected to interfere with 
important low-frequency cues. While the narrowband/single frequency 
threshold shift incurred may overlap with parts of the frequency range 
that sperm whales use for communication, any associated lost 
opportunities and capabilities would not be at a level that will impact 
reproduction or survival.
    Altogether, sperm whales are listed as endangered under the ESA and 
there are no known population trends. Our analysis suggests that a very 
small portion of the individuals within the MITT Study Area and Transit 
Corridor will be taken and disturbed at a low-moderate level, with 
those individuals disturbed on likely one day within a year. No 
mortality or Level A harassment is anticipated or authorized. This low 
magnitude and severity of harassment effects is not expected to result 
in impacts on the reproduction or survival of any individuals, let 
alone have impacts on annual rates of recruitment or survival, and 
therefore the total take will not adversely affect this species through 
impacts on annual rates of recruitment or survival. For these reasons, 
we have determined, in consideration of all of the effects of the 
Navy's activities combined, that the authorized take will have a 
negligible impact on sperm whales.
    Beaked Whales--This section builds on the broader odontocete 
discussion above (i.e., that information applies to beaked whales as 
well), except where we offer alternative information about the received 
levels for beaked whale for Level B harassment by behavioral 
disturbance, and brings together the discussion of the different types 
and amounts of take that different beaked whale species will incur, the 
applicable mitigation, and the status of each species to support the 
negligible impact determination for each species. For beaked whales, 
there is no Level A harassment or mortality anticipated or authorized.
    In Table 50 below for beaked whales, we indicate the total annual 
numbers of take by Level A and Level B harassment for the four species, 
and a number indicating the instances of total take as a percentage of 
the abundance in the MITT Study Area alone, as well as the MITT Study 
Area plus the Transit Corridor, which was calculated separately. While 
the density used to calculate take is the same for these two areas, the 
takes were calculated separately for the two areas for beaked whales, 
because the activity levels are higher in the MITT Study Area and it is 
helpful to understand the comparative impacts in the two areas. Note 
also that for beaked whales, the abundance within the MITT Study Area 
and Transit Corridor represents only a portion of the species 
abundance.

 Table 50--Annual Estimated Takes by Level B Harassment and Level A Harassment for Beaked Whales and Number Indicating the Instances of Total Take as a
                                           Percentage of Abundance in the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Instances of indicated types of incidental take (not all         Abundance        Instances of total
                                                     takes represent separate individuals, especially for    ----------------------  take as percentage
                                                                         disturbance)                                                   of abundance
                                                -------------------------------------------------------------                      ---------------------
                                                     Level B harassment       Level A        Total takes                    MITT
                    Species                     --------------------------- harassment ----------------------    MITT      study                  MITT
                                                                           ------------               MITT      study      area +      MITT      study
                                                                                           MITT      study       area     transit     study      area +
                                                   Behavioral       TTS                   study      area +               corridor     area     transit
                                                   disturbance                  PTS        area     transit                                     corridor
                                                                                                    corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blainville's beaked whale......................           1,691         27           0      1,698      1,718      3,083      3,376         55         51
Cuvier's beaked whale..........................             642          4           0        534        646      1,075      2,642         50         24
Ginkgo-toothed beaked whale....................           3,660         66           0      3,662      3,726      6,775      7,567         54         49
Longman's beaked whale.........................           5,959        107           0      6,056      6,066     11,148     11,253         54         54
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
  Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
  Study Area = Abundance in the MITT Study. Note that the total annual takes described here may be off by a digit due to rounding. This occurred here as
  the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
  number in the Estimated Take of Marine Mammals section.

    As discussed above, the majority of takes by Level B harassment by 
behavioral disturbance of odontocetes, and thereby beaked whales, is 
expected to be in the form of low to moderate severity of a generally 
shorter duration. The majority of takes by harassment of beaked whales 
in the MITT Study Area are caused by sources from the MFAS active sonar 
bin (which includes hull-mounted sonar) because they are high level 
narrowband sources that fall within the 1-10 kHz range, which overlap a 
more sensitive portion (though not the most sensitive) of the MF 
hearing range. Also, of the sources expected to result in take, they 
are used in a large portion of exercises (see Table 3). Most of the 
takes (96 percent) from the MF1 bin in the MITT Study Area would result 
from received levels between 148 and 160 dB SPL. For the remaining 
active sonar bin types, the percentages are as follows: LF4 = 99 
percent between 124 and 136 dB SPL, MF4 = 98 percent between 130 and 
148 dB SPL, MF5 = 97 percent between 100 and 142 dB SPL, and HF4 = 95 
percent between 100 and 148 dB SPL. Given the levels they are exposed 
to and their sensitivity, some responses would be of a lower severity, 
but many would likely be considered moderate.
    Research has shown that beaked whales are especially sensitive to 
the presence of human activity (Pirotta et al., 2012; Tyack et al., 
2011) and therefore have been assigned a lower harassment threshold, 
with lower received levels resulting in a higher percentage of 
individuals being harassed and a more distant distance cutoff (50 km 
for high source level, 25 km for moderate source level). Beaked whales 
have also been found to respond to naval sonar, in certain 
circumstances, in a manner that can lead to stranding and in a few 
cases, globally, beaked whale strandings have been causally associated 
with active sonar operation. However, as discussed in the Stranding 
section of the Potential Effects of Specified Activities on Marine 
Mammals and Their Habitat section,

[[Page 46407]]

NMFS has determined that the activities included in this 7-year rule 
are not reasonably likely to result in the mortality of beaked whales.
    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). 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 MFAS. Changes in the animal's dive behavior and 
locomotion were observed when received level reached 127 dB re 1 
[micro]Pa. However, 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; McCarthy et al., 2011; Moretti et al., 2009, 2010; Tyack et al., 
2010, 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., 2013b). 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. 
Cuvier's beaked whale responses suggested particular sensitivity to 
sound exposure consistent with results for Blainville's beaked whale.
    Populations of beaked whales and other odontocetes in the Bahamas 
and other Navy fixed ranges that have been operating for decades appear 
to be stable. Behavioral reactions (avoidance of the area of Navy 
activity) 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 (De Ruiter et al., 2013; 
Manzano-Roth et al., 2013; Moretti et al., 2014; Tyack et al., 2011). 
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, 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. More than eight years 
of passive acoustic monitoring on the Navy's instrumented range west of 
San Clemente Island documented no significant changes in annual and 
monthly beaked whale echolocation clicks, with the exception of 
repeated fall declines likely driven by natural beaked whale life 
history functions (DiMarzio et al., 2018). Finally, results from 
passive acoustic monitoring estimated that regional Cuvier's beaked 
whale densities were higher than indicated by NMFS' broad scale visual 
surveys for the U.S. West Coast (Hildebrand and McDonald, 2009).
    These beaked whale species are not listed as endangered or 
threatened species under the ESA, and there are no known biologically 
important areas identified for these species in the MITT Study Area. 
There have been no stock(s) specified for beaked whales found in the 
MITT Study Area and Transit Corridor, and there are no associated SARs. 
There is also no information on trends for these species within the 
MITT Study Area. All of the beaked whales species discussed in this 
section will benefit from the procedural mitigation measures described 
earlier in the Mitigation Measures section.
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disturbance), the number of estimated instances of take 
compared to the abundance is 50 to 55 percent in the MITT Study Area 
and 24 to 54 percent in the MITT Study Area and transit corridor 
combined (Table 50). Regarding the severity of those individual takes 
by Level B harassment by behavioral disturbance, we have explained that 
the duration of any exposure is expected to be between minutes and 
hours (i.e., relatively short) and the received sound levels largely 
below 160 dB, though with beaked whales, which are considered somewhat 
more sensitive, this could mean that some individuals will leave 
preferred habitat for a day (i.e., moderate level takes). However, 
while interrupted feeding bouts are a known response and concern for 
odontocetes, we also know that there are often viable alternative 
habitat options nearby. Regarding the severity of takes by TTS, they 
are expected to be low-level, of short duration, and mostly not in a 
frequency band that would be expected to interfere with beaked whale 
communication or other important low-frequency cues. Therefore, the 
associated lost opportunities and capabilities are not at a level that 
will impact reproduction or survival. As mentioned earlier in the 
odontocete overview, we anticipate more severe effects from takes when 
animals are exposed to higher received levels or sequential days of 
impacts.
    Altogether, none of the four beaked whale species are listed under 
the ESA and there are no known population trends. Our analysis suggests 
that fewer than half of the individuals of each species in the MITT 
Study Area and Transit Corridor will be taken and disturbed at a low or 
moderate level, with those individuals likely not

[[Page 46408]]

disturbed on more than a few non-sequential days a year. No mortality 
or Level A harassment is anticipated or authorized. This low magnitude 
and low to moderate severity of harassment effects is not expected to 
result in impacts on individual reproduction or survival, let alone 
have impacts on annual rates of recruitment or survival and, therefore, 
the total take will not adversely affect this species through impacts 
on annual rates of recruitment or survival. For these reasons, we have 
determined, in consideration of all of the effects of the Navy's 
activities combined, that the authorized take will have a negligible 
impact on these four beaked whale species.
    Small Whales and Dolphins--This section builds on the broader 
discussion above and brings together the discussion of the different 
types and amounts of take that different small whale and dolphin 
species are likely to incur, the applicable mitigation, and the status 
of the species to support the negligible impact determinations for each 
species.
    In Table 51 below for dolphins and small whales, we indicate for 
each species the total annual numbers of take by Level A and Level B 
harassment, and a number indicating the instances of total take as a 
percentage of abundance in the MITT Study Area alone, as well as the 
MITT Study Area plus the Transit Corridor, which was calculated 
separately. While the density used to calculate take is the same for 
these two areas, the takes were calculated separately for the two areas 
for dolphins and small whales, because the activity levels are higher 
in the MITT Study Area and it is helpful to understand the comparative 
impacts in the two areas. Note also that for dolphins and small whales, 
the abundance within the MITT Study Area and Transit Corridor 
represents only a portion of the species abundance.

Table 51--Annual Estimated Takes by Level B Harassment and Level A Harassment for Dolphins and Small Whales and Number Indicating the Instances of Total
                                      Take as a Percentage of Abundance in the MITT Study Area and Transit Corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Instances of indicated types of incidental take (not all         Abundance        Instances of total
                                                     takes represent separate individuals, especially for    ----------------------  take as percentage
                                                                         disturbance)                                                   of abundance
                                                -------------------------------------------------------------                      ---------------------
                                                     Level B harassment       Level A        Total takes                    MITT
                    Species                     --------------------------- harassment ----------------------    MITT      study                  MITT
                                                                           ------------               MITT      study      area +      MITT      study
                                                                                           MITT      study       area     transit     study      area +
                                                   Behavioral       TTS                   study      area +               corridor     area     transit
                                                   disturbance                  PTS        area     transit                                     corridor
                                                                                                    corridor
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin.............................             116         21           0        132        137        753      1,076         17         13
False killer whale.............................             641        121           0        759        762      3,979      4,218         19         18
Fraser's dolphin...............................          11,326      1,952           1     13,261     13,279     75,420     76,476         18         17
Killer whale...................................              36          8           0         44         44        215        253         20         17
Melon-headed whale.............................           2,306        509           0      2,798      2,815     15,432     16,551         18         17
Pantropical spotted dolphin....................          12,078      2,818           1     14,820     14,897     81,013     85,755         18         17
Pygmy killer whale.............................              87         17           0        103        104        502        527         21         20
Risso's dolphin................................           2,650        520           0      3,166      3,170     16,991     17,184         19         18
Rough-toothed dolphin..........................             161         36           0        185        197      1,040      1,815         18         11
Short-finned pilot whale.......................             987        176           0      1,150      1,163      5,700      6,583         20         18
Spinner dolphin................................           1,185        229           1      1,404      1,415      4,449      5,232         32         27
Striped dolphin................................           3,256        751           0      3,956      4,007     22,081     24,528         18         16
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abundance was calculated using the following formulas: (1) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT Study
  Area transit corridor = Abundance in the transit corridor and (2) Density from the Technical Report in animals/km\2\ x spatial extent of the MITT
  Study Area = Abundance in the MITT Study. Note that the total annual takes described here may be off by a digit due to rounding. This occurred here as
  the Level B harassment takes are broken down further into Behavioral Disturbance and TTS compared to the Level B harassment takes presented as one
  number in the Estimated Take of Marine Mammals section.

    As discussed above, the majority of takes by Level B harassment by 
behavioral disturbance of odontocetes, and thereby dolphins and small 
whales, from hull-mounted sonar (MFAS) in the MITT Study Area would 
result from received levels between 154 and 172 dB SPL. Therefore, the 
majority of takes by Level B harassment are expected to be in the form 
of low to occasionally moderate severity of a generally shorter 
duration. As mentioned earlier in this section, we anticipate more 
severe effects from takes when animals are exposed to higher received 
levels or for longer durations. Occasional milder Level B harassment by 
behavioral disturbance, as is expected here, is unlikely to cause long-
term consequences for either individual animals or populations that 
have any effect on reproduction or survival. One Level A harassment is 
anticipated and authorized for three species (Fraser's dolphin, 
pantropical spotted dolphin, and spinner dolphin).
    Research and observations show that if delphinids 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. 
Delphinids 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. Some dolphin species (the more 
surface-dwelling taxa--typically those with ``dolphin'' in the common 
name, such as bottlenose dolphins, spotted dolphins, spinner dolphins, 
rough-toothed dolphins, etc., but not Risso's dolphin), especially 
those residing in more industrialized or busy areas, have demonstrated 
more tolerance for disturbance and loud sounds and many of these 
species are known to approach vessels to bow-ride. These species are 
often considered generally less sensitive to disturbance. Dolphins and 
small whales that reside in deeper waters and generally have fewer 
interactions with human activities are more likely to demonstrate more 
typical avoidance reactions and foraging interruptions as described 
above in the odontocete overview.
    All the dolphin and small whale species discussed in this section 
will benefit from the procedural mitigation measures described earlier 
in the Mitigation Measures section. Additionally, the Agat Bay 
Nearshore Geographic Mitigation Area will provide protection for 
spinner dolphins as the Navy will not use in-water explosives or

[[Page 46409]]

MF1 ship hull-mounted mid-frequency active sonar in this area. High use 
areas for spinner dolphins including Agat Bay are where animals 
congregate during the day to rest (Amesbury et al., 2001; Eldredge, 
1991). Behavioral disruptions during resting periods can adversely 
impact health and energetic budgets by not allowing animals to get the 
needed rest and/or by creating the need to travel and expend additional 
energy to find other suitable resting areas. Avoiding sonar and 
explosives in this area reduces the likelihood of impacts that would 
affect reproduction and survival.
    None of the small whale and dolphin species are listed as 
endangered or threatened species under the ESA. As noted above, an 
important resting area has been identified for spinner dolphins, and 
mitigation has been included to reduce impacts in the area. There have 
been no stock(s) specified for small whales and dolphins found in the 
MITT Study Area and Transit Corridor, and there are no associated SARs. 
There is also no information on trends for these species within the 
MITT Study Area.
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disturbance), the number of estimated total instances of 
take compared to the abundance is 32 percent for spinner dolphins and 
17 to 21 percent for the remaining dolphins and small whales in the 
MITT Study Area. The number of estimated total instances of take 
compared to the abundance is 27 percent for spinner dolphins and 20 
percent or less for the remaining dolphins and small whales in the MITT 
Study and transit corridor combined (Table 51).
    Regarding the severity of those individual takes by Level B 
harassment by behavioral disturbance, we have explained the duration of 
any exposure is expected to be between minutes and hours (i.e., 
relatively short) and the received sound levels largely below 172 dB 
(i.e., of a lower, to occasionally moderate, level and less likely to 
evoke a severe response). Regarding the severity of takes by TTS, they 
are expected to be low-level, of short duration, and mostly not in a 
frequency band that would be expected to interfere with communication 
or other important low-frequency cues. The associated lost 
opportunities and capabilities are not at a level that will impact 
reproduction or survival. One individual each of three species (spinner 
dolphin, Fraser's dolphin, and pantropical spotted dolphin) is 
estimated to be taken by one PTS annually, of likely low severity as 
described previously. A small permanent loss of hearing sensitivity 
(PTS) may include some degree of energetic costs for compensating or 
may mean some small loss of opportunities or detection capabilities, 
but at the expected scale the estimated takes by Level A harassment by 
PTS for spinner dolphin, Fraser's dolphin, and pantropical spotted 
dolphin are unlikely to impact behaviors, opportunities, or detection 
capabilities to a degree that will interfere with reproductive success 
or survival of any individuals, let alone affect annual rates of 
recruitment or survival.
    Altogether, none of the small whale or dolphin species are listed 
under the ESA and there are no known population trends. Our analysis 
suggests that only a small portion of the individuals of any of these 
species in the MITT Study Area or Transit Corridor will be taken and 
disturbed at a low-moderate level, with those individuals likely 
disturbed no more than a few non-sequential days a year. One take by 
PTS for three dolphin species is anticipated and authorized, but at the 
expected scale the estimated take by Level A harassment by PTS is 
unlikely to impact behaviors, opportunities, or detection capabilities 
to a degree that would interfere with reproductive success or survival 
of any individuals, let alone annual rates of recruitment or survival. 
This low magnitude and severity of harassment effects is not expected 
to result in impacts on the reproduction or survival of any 
individuals, let alone have impacts on annual rates of recruitment or 
survival and, therefore, the total take will not adversely affect these 
species through impacts on annual rates of recruitment or survival. For 
these reasons, we have determined, in consideration of all of the 
effects of the Navy's activities combined, that the authorized take 
will have a negligible impact on all twelve of these species of small 
whales and dolphins.

Determination

    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the monitoring and mitigation 
measures, NMFS finds that the total marine mammal take from the 
Specified Activities will have a negligible impact on all affected 
marine mammal species.

Subsistence Harvest of Marine Mammals

    There are no subsistence uses or harvest of marine mammals in the 
geographic area affected by the specified activities. Therefore, NMFS 
has determined that the total taking affecting species will not have an 
unmitigable adverse impact on the availability of the species for 
taking for subsistence purposes.

Classification

Endangered Species Act

    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 MITT Study Area: Blue whale, fin whale, 
humpback whale, sei whale, and sperm whale. There is no ESA-designated 
critical habitat for any species in the MITT Study Area. The Navy 
consulted with NMFS pursuant to section 7 of the ESA for MITT 
activities, and NMFS also consulted internally on the issuance of these 
regulations and LOA under section 101(a)(5)(A) of the MMPA. NMFS issued 
a Biological Opinion concluding that the issuance of the rule and 
subsequent LOA is not likely to jeopardize the continued existence of 
the threatened and endangered species under NMFS' jurisdiction and is 
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 at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.

National Marine Sanctuaries Act

    There are no national marine sanctuaries in the MITT Study Area. 
Therefore, no consultation under the National Marine Sanctuaries Act is 
required.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must evaluate its proposed actions and alternatives with respect 
to potential impacts on the human environment. NMFS participated as a 
cooperating agency on the 2020 MITT FSEIS/OEIS, which was published on 
June 5, 2020, and is available at http://www.MITT-eis.com. In 
accordance with 40 CFR 1506.3, NMFS independently reviewed and 
evaluated the 2020 MITT FSEIS/OEIS and determined that it is adequate 
and sufficient to meet our responsibilities under NEPA for the issuance 
of this rule and associated LOA. NOAA therefore adopted the 2020 MITT 
FSEIS/OEIS. NMFS has prepared a separate Record of Decision. NMFS' 
Record of Decision for adoption of the 2020 MITT FSEIS/OEIS

[[Page 46410]]

and issuance of this final rule and subsequent LOA can be found at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.

Executive Order 12866

    The Office of Management and Budget has determined that this rule 
is not significant for purposes of Executive Order 12866.

Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility Act (RFA), the Chief Counsel 
for Regulation of the Department of Commerce certified to the Chief 
Counsel for Advocacy of the Small Business Administration during the 
proposed rule stage that this action would not have a significant 
economic impact on a substantial number of small entities. The factual 
basis for the certification was published in the proposed rule and is 
not repeated here. No comments were received regarding this 
certification. As a result, a regulatory flexibility analysis was not 
required and none was prepared.

Waiver of Delay in Effective Date

    NMFS 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 this final rule. No individual or entity 
other than the Navy is affected by the provisions of these regulations. 
The Navy has requested that this final rule take effect on or before 
July 31, 2020, to accommodate the Navy's LOA expiring on August 3, 
2020, so as to not cause a disruption in training and testing 
activities. NMFS was unable to accommodate the 30-day delay of 
effectiveness period due to the need to consider new information that 
became available in June 2020, as well as a revised humpback whale 
analysis that arose through the ESA section 7 consultation. The waiver 
of the 30-day delay of the effective date of the final rule will ensure 
that the MMPA final rule and LOA are in place by the time the previous 
authorizations expire. Any delay in finalizing the rule would result in 
either: (1) A suspension of planned naval training and testing, which 
would disrupt vital training and testing essential to national 
security; or (2) the Navy's procedural non-compliance with the MMPA 
(should the Navy conduct training and testing without an LOA), thereby 
resulting in the potential for unauthorized takes of marine mammals. 
Moreover, the Navy is ready to implement the regulations immediately. 
For these reasons, NMFS finds good cause to waive the 30-day delay in 
the effective date. In addition, the rule authorizes incidental take of 
marine mammals that would otherwise be prohibited under the statute. 
Therefore, by granting an exception to the Navy, the rule will relieve 
restrictions under the MMPA, which provides a separate basis for 
waiving the 30-day effective date for the rule.

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 15, 2020.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, 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 follows:

    Authority: 16 U.S.C. 1361 et seq., unless otherwise noted.


0
2. Revise subpart J 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 geographical region.
218.91 Effective dates.
218.92 Permissible methods of taking.
218.93 Prohibitions.
218.94 Mitigation requirements.
218.95 Requirements for monitoring and reporting.
218.96 Letters of Authorization.
218.97 Renewals 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 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 described in paragraph 
(b) of this section and that occurs incidental to the activities listed 
in paragraph (c) of this section.
    (b) The taking of marine mammals by the Navy under this subpart may 
be authorized in a Letter of Authorization (LOA) only if it occurs 
within the Mariana Islands Training and Testing (MITT) Study Area. The 
MITT Study Area is comprised of three components: The Mariana Islands 
Range Complex (MIRC), additional areas on the high seas, and a transit 
corridor between the MIRC and the Hawaii Range Complex (HRC). The MIRC 
includes the waters south of Guam to north of Pagan (Commonwealth of 
the Northern Mariana Islands (CNMI)), and from the Pacific Ocean east 
of the Mariana Islands to the Philippine Sea to the west, encompassing 
501,873 square nautical miles (nmi\2\) of open ocean. The additional 
areas of the high seas include the area to the north of the MIRC that 
is within the U.S. Exclusive Economic Zone (EEZ) of the CNMI and the 
areas to the west of the MIRC. The transit corridor is outside the 
geographic boundaries of the MIRC and represents a great circle route 
(i.e., the shortest distance) across the high seas for Navy ships 
transiting between the MIRC and the HRC. Additionally, the MITT Study 
Area includes pierside locations in the Apra Harbor Naval Complex.
    (c) The taking of marine mammals by the Navy is only authorized if 
it occurs incidental to the Navy conducting training and testing 
activities, including:
    (1) Training. (i) Amphibious warfare;
    (ii) Anti-submarine warfare;
    (iii) Mine warfare;
    (vi) Surface warfare; and
    (vii) Other training activities.
    (2) Testing. (i) Naval Air Systems Command Testing Activities;
    (ii) Naval Sea Systems Command Testing Activities; and
    (iii) Office of Naval Research Testing Activities.


Sec.  218.91   Effective dates.

    Regulations in this subpart are effective from July 31, 2020, to 
July 30, 2027.


Sec.  218.92   Permissible methods of taking.

    (a) Under an LOA issued pursuant to Sec. Sec.  216.106 of this 
section and 218.96, the Holder of the LOA (hereinafter ``Navy'') may 
incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  218.90(b) by Level A harassment and Level B 
harassment associated with the use of active sonar and other acoustic 
sources and explosives, provided the activity is in compliance with all 
terms, conditions, and requirements of the regulations in this subpart 
and the applicable LOA.
    (b) The incidental take of marine mammals by the activities listed 
in Sec.  218.90(c) is limited to the species listed in Table 1 of this 
section.

[[Page 46411]]



                       Table 1 to Sec.   218.92(b)
------------------------------------------------------------------------
                  Species                          Scientific name
------------------------------------------------------------------------
Blue whale................................  Balaenoptera musculus.
Bryde's whale.............................  Balaenoptera edeni.
Fin whale.................................  Balaenoptera physalus.
Humpback whale............................  Megaptera novaeangliae.
Minke whale...............................  Balaenoptera acutorostrata.
Omura's whale.............................  Balaenoptera omurai.
Sei whale.................................  Balaenoptera borealis.
Blainville's beaked whale.................  Mesoplodon densirostris.
Common bottlenose dolphin.................  Tursiops truncatus.
Cuvier's beaked whale.....................  Ziphius cavirostris.
Dwarf sperm whale.........................  Kogia sima.
False killer whale........................  Pseudorca crassidens.
Fraser's dolphin..........................  Lagenodelphis hosei.
Ginkgo-toothed beaked whale...............  Mesoplodon ginkgodens.
Killer whale..............................  Orcinus orca.
Longman's beaked whale....................  Indopacetus pacificus.
Melon-headed whale........................  Peponocephala electra.
Pantropical spotted dolphin...............  Stenella attenuata.
Pygmy killer whale........................  Feresa attenuata.
Pygmy sperm whale.........................  Kogia breviceps.
Risso's dolphin...........................  Grampus griseus.
Rough-toothed dolphin.....................  Steno bredanensis.
Short-finned pilot whale..................  Globicephala macrorhynchus.
Sperm whale...............................  Physeter macrocephalus.
Spinner dolphin...........................  Stenella longirostris.
Striped dolphin...........................  Stenella coeruleoalba.
------------------------------------------------------------------------

Sec.  218.93   Prohibitions.

    Notwithstanding incidental takings contemplated in Sec.  218.92(a) 
and authorized by an LOA issued under Sec. Sec.  216.106 of this 
section and 218.96, no person in connection with the activities listed 
in Sec.  218.90(c) may:
    (a) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or an LOA issued under Sec. Sec.  216.106 
of this section and 218.96;
    (b) Take any marine mammal not specified in Sec.  218.92(b);
    (c) Take any marine mammal specified in Sec.  218.92(b) in any 
manner other than as specified in the LOA issued under Sec. Sec.  
216.106 of this chapter and 218.96; or
    (d) Take a marine mammal specified in Sec.  218.92(b) if NMFS 
determines such taking results in more than a negligible impact on the 
species of such marine mammal.


Sec.  218.94   Mitigation requirements.

    When conducting the activities identified in Sec.  218.90(c), the 
mitigation measures contained in any LOA issued under Sec. Sec.  
216.106 of this section and 218.96 must be implemented. These 
mitigation measures include, but are not limited to:
    (a) Procedural mitigation. Procedural mitigation is mitigation that 
the Navy must implement whenever and wherever an applicable training or 
testing activity takes place within the MITT Study Area for each 
applicable activity category or stressor category and includes acoustic 
stressors (i.e., active sonar and other transducers, weapons firing 
noise), explosive stressors (i.e., sonobuoys, torpedoes, medium-caliber 
and large-caliber projectiles, missiles and rockets, bombs, sinking 
exercises, mines, anti-swimmer grenades), and physical disturbance and 
strike stressors (i.e., vessel movement; towed in-water devices; small-
, medium-, and large-caliber non-explosive practice munitions; non-
explosive missiles and rockets; and non-explosive bombs and mine 
shapes).
    (1) Environmental awareness and education. Appropriate Navy 
personnel (including civilian personnel) involved in mitigation and 
training or testing reporting under the specified activities will 
complete one or more modules of the U.S. Navy Afloat Environmental 
Compliance Training Series, as identified in their career path training 
plan. Modules include: Introduction to the U.S. Navy Afloat 
Environmental Compliance Training Series, Marine Species Awareness 
Training; U.S. Navy Protective Measures Assessment Protocol; and U.S. 
Navy Sonar Positional Reporting System and Marine Mammal Incident 
Reporting.
    (2) Active sonar. Active sonar includes low-frequency active sonar, 
mid-frequency active sonar, and high-frequency active sonar. For 
vessel-based activities, mitigation applies only to sources that are 
positively controlled and deployed from manned surface vessels (e.g., 
sonar sources towed from manned surface platforms). For aircraft-based 
activities, mitigation applies only to sources that are positively 
controlled and deployed from manned aircraft that do not operate at 
high altitudes (e.g., rotary-wing aircraft). Mitigation does not apply 
to active sonar sources deployed from unmanned aircraft or aircraft 
operating at high altitudes (e.g., maritime patrol aircraft).
    (i) Number of Lookouts and observation platform--(A) Hull-mounted 
sources. One Lookout must be positioned for platforms with space or 
manning restrictions while underway (at the forward part of a small 
boat or ship) and platforms using active sonar while moored or at 
anchor (including pierside); and two Lookouts must be positioned for 
platforms without space or manning restrictions while underway (at the 
forward part of the ship).
    (B) Sources that are not hull-mounted sources. One Lookout must be 
positioned on the ship or aircraft conducting the activity.
    (ii) Mitigation zone and requirements. The mitigation zones must be 
the zones as described in paragraphs (a)(2)(ii)(B) and (C) of this 
section.
    (A) Prior to the initial start of the activity (e.g., when 
maneuvering on station), Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must relocate or delay the start of active sonar transmission.
    (B) During the activity for low-frequency active sonar at or above 
200 dB and hull-mounted mid-frequency active sonar, Navy personnel must 
observe the mitigation zone for marine mammals and power down active 
sonar transmission by 6 dB if marine mammals are observed within 1,000 
yd of the sonar source; power down by an additional 4 dB (for a total 
of 10 dB) if marine mammals are observed within 500 yd of the sonar 
source; and cease transmission if marine mammals are observed within 
200 yd of the sonar source.
    (C) During the activity for low-frequency active sonar below 200 
dB, mid-frequency active sonar sources that are not hull mounted, and 
high-frequency active sonar, Navy personnel must observe the mitigation 
zone for marine mammals and cease active sonar transmission if marine 
mammals are observed within 200 yd of the sonar source.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing or powering up active sonar transmission) until 
one of the following conditions has been 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, speed, and 
movement relative to the sonar source; the mitigation zone has been 
clear from any additional sightings for 10 minutes (min) for aircraft-
deployed sonar sources or 30 min for vessel-deployed sonar sources; for 
mobile activities, the active sonar

[[Page 46412]]

source has transited a distance equal to double that of the mitigation 
zone size beyond the location of the last sighting; or for activities 
using hull-mounted sonar where a dolphin(s) is observed in the 
mitigation zone, the Lookout concludes that the dolphin(s) is 
deliberately closing in on the ship to ride the ship's bow wave, and is 
therefore out of the main transmission axis of the sonar (and there are 
no other marine mammal sightings within the mitigation zone).
    (3) Weapons firing noise. Weapons firing noise associated with 
large-caliber gunnery activities.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned on the ship conducting the firing. Depending on the 
activity, the Lookout could be the same as the one provided for under 
``Explosive medium-caliber and large-caliber projectiles'' or under 
``Small-, medium-, and large-caliber non-explosive practice munitions'' 
in paragraphs (a)(6)(i) and (a)(15)(i) of this section.
    (ii) Mitigation zone and requirements. The mitigation zone must be 
thirty degrees on either side of the firing line out to 70 yd from the 
muzzle of the weapon being fired.
    (A) Prior to the initial start of the activity, Navy personnel must 
observe the mitigation zone for marine mammals; if marine mammals are 
observed, Navy personnel must relocate or delay the start of weapons 
firing.
    (B) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease weapons firing.
    (C) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing weapons firing) until one of the following 
conditions has been 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, speed, and movement relative to the 
firing ship; the mitigation zone has been clear from any additional 
sightings for 30 min; or for mobile activities, the firing ship has 
transited a distance equal to double that of the mitigation zone size 
beyond the location of the last sighting.
    (4) Explosive sonobuoys--(i) Number of Lookouts and observation 
platform. One Lookout must be positioned in an aircraft or on a small 
boat. If additional platforms are participating in the activity, Navy 
personnel positioned on those assets (e.g., safety observers, 
evaluators) must support observing the mitigation zone for marine 
mammals and other applicable biological resources while performing 
their regular duties.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 600 yd around an explosive sonobuoy.
    (B) Prior to the initial start of the activity (e.g., during 
deployment of a sonobuoy pattern, which typically lasts 20-30 min), 
Navy personnel must conduct passive acoustic monitoring for marine 
mammals and use information from detections to assist visual 
observations. Navy personnel also must visually observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must relocate or delay the start of sonobuoy or source/receiver pair 
detonations.
    (C) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease sonobuoy or source/receiver pair detonations.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing detonations) until one of the following conditions 
has been 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, speed, and movement relative to the 
sonobuoy; or the mitigation zone has been clear from any additional 
sightings for 10 min when the activity involves aircraft that have fuel 
constraints (e.g., helicopter), or 30 min when the activity involves 
aircraft that are not typically fuel constrained.
    (E) After completion of the activity (e.g., prior to maneuvering 
off station), when practical (e.g., when platforms are not constrained 
by fuel restrictions or mission-essential follow-on commitments), Navy 
personnel must observe for marine mammals in the vicinity of where 
detonations occurred; if any injured or dead marine mammals are 
observed, Navy personnel must follow established incident reporting 
procedures. If additional platforms are supporting this activity (e.g., 
providing range clearance), Navy personnel on these assets must assist 
in the visual observation of the area where detonations occurred.
    (5) Explosive torpedoes--(i) Number of Lookouts and observation 
platform. One Lookout must be positioned in an aircraft. If additional 
platforms are participating in the activity, Navy personnel positioned 
on those assets (e.g., safety observers, evaluators) must support 
observing the mitigation zone for marine mammals and other applicable 
biological resources while performing their regular duties.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 2,100 yd around the intended impact location.
    (B) Prior to the initial start of the activity (e.g., during 
deployment of the target), Navy personnel must conduct passive acoustic 
monitoring for marine mammals and use the information from detections 
to assist visual observations. Navy personnel also must visually 
observe the mitigation zone for marine mammals; if marine mammals are 
observed, Navy personnel must relocate or delay the start of firing.
    (C) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals. If marine mammals are observed, Navy personnel 
must cease firing.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been 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, speed, and movement relative to the 
intended impact location; or the mitigation zone has been clear from 
any additional sightings for 10 min when the activity involves aircraft 
that have fuel constraints, or 30 min when the activity involves 
aircraft that are not typically fuel constrained.
    (E) After completion of the activity (e.g., prior to maneuvering 
off station), Navy personnel must when practical (e.g., when platforms 
are not constrained by fuel restrictions or mission-essential follow-on 
commitments), observe for marine mammals in the vicinity of where 
detonations occurred; if any injured or dead marine mammals are 
observed, Navy personnel must follow established incident reporting 
procedures. If additional platforms are supporting this activity (e.g., 
providing range clearance), Navy personnel on these assets must assist 
in the visual observation of the area where detonations occurred.

[[Page 46413]]

    (6) Explosive medium-caliber and large-caliber projectiles. Gunnery 
activities using explosive medium-caliber and large-caliber 
projectiles. Mitigation applies to activities using a surface target.
    (i) Number of Lookouts and observation platform. One Lookout must 
be on the vessel or aircraft conducting the activity. For activities 
using explosive large-caliber projectiles, depending on the activity, 
the Lookout could be the same as the one described in ``Weapons firing 
noise'' in paragraph (a)(3)(i) of this section. If additional platforms 
are participating in the activity, Navy personnel positioned on those 
assets (e.g., safety observers, evaluators) must support observing the 
mitigation zone for marine mammals and other applicable biological 
resources while performing their regular duties.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 200 yd around the intended impact location for air-to-surface 
activities using explosive medium-caliber projectiles.
    (B) The mitigation zone must be 600 yd around the intended impact 
location for surface-to-surface activities using explosive medium-
caliber projectiles.
    (C) The mitigation zone must be 1,000 yd around the intended impact 
location for surface-to-surface activities using explosive large-
caliber projectiles.
    (D) Prior to the initial start of the activity (e.g., when 
maneuvering on station), Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must relocate or delay the start of firing.
    (E) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease firing.
    (F) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been 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, speed, and movement relative to the 
intended impact location; the mitigation zone has been clear from any 
additional sightings for 10 min for aircraft-based firing or 30 min for 
vessel-based firing; or for activities using mobile targets, the 
intended impact location has transited a distance equal to double that 
of the mitigation zone size beyond the location of the last sighting.
    (G) After completion of the activity (e.g., prior to maneuvering 
off station), Navy personnel must, when practical (e.g., when platforms 
are not constrained by fuel restrictions or mission-essential follow-on 
commitments), observe for marine mammals in the vicinity of where 
detonations occurred; if any injured or dead marine mammals are 
observed, Navy personnel must follow established incident reporting 
procedures. If additional platforms are supporting this activity (e.g., 
providing range clearance), Navy personnel on these assets must assist 
in the visual observation of the area where detonations occurred.
    (7) Explosive missiles and rockets. Aircraft-deployed explosive 
missiles and rockets. Mitigation applies to activities using a surface 
target.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned in an aircraft. If additional platforms are participating 
in the activity, Navy personnel positioned on those assets (e.g., 
safety observers, evaluators) must support observing the mitigation 
zone for marine mammals and other applicable biological resources while 
performing their regular duties.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 900 yd around the intended impact location for missiles or rockets 
with 0.6-20 lb net explosive weight.
    (B) 2,000 yd around the intended impact location for missiles with 
21-500 lb net explosive weight.
    (C) Prior to the initial start of the activity (e.g., during a fly-
over of the mitigation zone), Navy personnel must observe the 
mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must relocate or delay the start of firing.
    (D) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease firing.
    (E) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been 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, speed, and movement relative to the 
intended impact location; or the mitigation zone has been clear from 
any additional sightings for 10 min when the activity involves aircraft 
that have fuel constraints, or 30 min when the activity involves 
aircraft that are not typically fuel constrained.
    (F) After completion of the activity (e.g., prior to maneuvering 
off station), Navy personnel must, when practical (e.g., when platforms 
are not constrained by fuel restrictions or mission-essential follow-on 
commitments), observe for marine mammals in the vicinity of where 
detonations occurred; if any injured or dead marine mammals are 
observed, Navy personnel must follow established incident reporting 
procedures. If additional platforms are supporting this activity (e.g., 
providing range clearance), Navy personnel on these assets will assist 
in the visual observation of the area where detonations occurred.
    (8) Explosive bombs--(i) Number of Lookouts and observation 
platform. One Lookout must be positioned in an aircraft conducting the 
activity. If additional platforms are participating in the activity, 
Navy personnel positioned on those assets (e.g., safety observers, 
evaluators) must support observing the mitigation zone for marine 
mammals and other applicable biological resources while performing 
their regular duties.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 2,500 yd around the intended target.
    (B) Prior to the initial start of the activity (e.g., when arriving 
on station), Navy personnel must observe the mitigation zone for marine 
mammals; if marine mammals are observed, Navy personnel must relocate 
or delay the start of bomb deployment.
    (C) During the activity (e.g., during target approach), Navy 
personnel must observe the mitigation zone for marine mammals; if 
marine mammals are observed, Navy personnel must cease bomb deployment.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing bomb deployment) until one of the following 
conditions has been 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, speed, and movement relative to the 
intended target; the mitigation zone has been

[[Page 46414]]

clear from any additional sightings for 10 min; or for activities using 
mobile targets, the intended target has transited a distance equal to 
double that of the mitigation zone size beyond the location of the last 
sighting.
    (E) After completion of the activity (e.g., prior to maneuvering 
off station), Navy personnel must, when practical (e.g., when platforms 
are not constrained by fuel restrictions or mission-essential follow-on 
commitments), observe for marine mammals in the vicinity of where 
detonations occurred; if any injured or dead marine mammals are 
observed, Navy personnel must follow established incident reporting 
procedures. If additional platforms are supporting this activity (e.g., 
providing range clearance), Navy personnel on these assets must assist 
in the visual observation of the area where detonations occurred.
    (9) Sinking exercises--(i) Number of Lookouts and observation 
platform. Two Lookouts (one must be positioned in an aircraft and one 
must be positioned on a vessel). If additional platforms are 
participating in the activity, Navy personnel positioned on those 
assets (e.g., safety observers, evaluators) must support observing the 
mitigation zone for marine mammals and other applicable biological 
resources while performing their regular duties.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 2.5 nmi around the target ship hulk.
    (B) Prior to the initial start of the activity (90 min prior to the 
first firing), Navy personnel must conduct aerial observations of the 
mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must delay the start of firing.
    (C) During the activity, Navy personnel must conduct passive 
acoustic monitoring for marine mammals and use the information from 
detections to assist visual observations. Navy personnel must visually 
observe the mitigation zone for marine mammals from the vessel; if 
marine mammals are observed, Navy personnel must cease firing. 
Immediately after any planned or unplanned breaks in weapons firing of 
longer than two hours, Navy personnel must observe the mitigation zone 
for marine mammals from the aircraft and vessel; if marine mammals are 
observed, Navy personnel must delay recommencement of firing.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been 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, speed, and movement relative to the target 
ship hulk; or the mitigation zone has been clear from any additional 
sightings for 30 min.
    (E) After completion of the activity (for two hours after sinking 
the vessel or until sunset, whichever comes first), Navy personnel must 
observe for marine mammals in the vicinity of where detonations 
occurred; if any injured or dead marine mammals are observed, Navy 
personnel must follow established incident reporting procedures. If 
additional platforms are supporting this activity (e.g., providing 
range clearance), Navy personnel on these assets will assist in the 
visual observation of the area where detonations occurred.
    (10) Explosive mine countermeasure and neutralization activities--
(i) Number of Lookouts and observation platform. (A) One Lookout must 
be positioned on a vessel or in an aircraft.
    (B) If additional platforms are participating in the activity, Navy 
personnel positioned on those assets (e.g., safety observers, 
evaluators) must support observing the mitigation zone for marine 
mammals and other applicable biological resources while performing 
their regular duties.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 600 yd around the detonation site.
    (B) Prior to the initial start of the activity (e.g., when 
maneuvering on station; typically 10 min when the activity involves 
aircraft that have fuel constraints, or 30 min when the activity 
involves aircraft that are not typically fuel constrained), Navy 
personnel must observe the mitigation zone for marine mammals; if 
marine mammals are observed, Navy personnel must relocate or delay the 
start of detonations.
    (C) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease detonations.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing detonations) until one of the following conditions 
has been 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, speed, and movement relative to detonation 
site; or the mitigation zone has been clear from any additional 
sightings for 10 min when the activity involves aircraft that have fuel 
constraints, or 30 min when the activity involves aircraft that are not 
typically fuel constrained.
    (F) After completion of the activity (typically 10 min when the 
activity involves aircraft that have fuel constraints, or 30 min when 
the activity involves aircraft that are not typically fuel 
constrained), Navy personnel must observe for marine mammals in the 
vicinity of where detonations occurred; if any injured or dead marine 
mammals are observed, Navy personnel must follow established incident 
reporting procedures. If additional platforms are supporting this 
activity (e.g., providing range clearance), Navy personnel on these 
assets must assist in the visual observation of the area where 
detonations occurred.
    (11) Explosive mine neutralization activities involving Navy 
divers--(i) Number of Lookouts and observation platform. (A) Two 
Lookouts (two small boats with one Lookout each, or one Lookout must be 
on a small boat and one must be in a rotary-wing aircraft) when 
implementing the smaller mitigation zone.
    (B) Four Lookouts (two small boats with two Lookouts each), and a 
pilot or member of an aircrew which must serve as an additional Lookout 
if aircraft are used during the activity, must be used when 
implementing the larger mitigation zone.
    (C) All divers placing the charges on mines will support the 
Lookouts while performing their regular duties and will report 
applicable sightings to their supporting small boat or Range Safety 
Officer.
    (D) If additional platforms are participating in the activity, Navy 
personnel positioned on those assets (e.g., safety observers, 
evaluators) must support observing the mitigation zone for marine 
mammals and other applicable biological resources while performing 
their regular duties.
    (ii) Mitigation zone and requirements. (A) For Lookouts on small 
boats or aircraft, the mitigation zone must be 500 yd around the 
detonation site under positive control.
    (B) For Lookouts on small boats or aircraft, the mitigation zone 
must be 1,000 yd around the detonation site during all activities using 
time-delay fuses.
    (C) For divers, the mitigation zone must be the underwater 
detonation

[[Page 46415]]

location, which is defined as the sea space within the divers' range of 
visibility but no further than the mitigation zone specified for 
Lookouts on small boats or aircraft (500 yd or 1,000 yd depending on 
the charge type).
    (D) Prior to the initial start of the activity (when maneuvering on 
station for activities under positive control; 30 min for activities 
using time-delay firing devices), Navy Lookouts on small boats or 
aircraft, must observe the mitigation zone for marine mammals; if 
marine mammals are observed, Navy personnel must relocate or delay the 
start of detonations or fuse initiation.
    (E) During the activity, Navy Lookouts on small boats or aircraft, 
must observe the mitigation zone for marine mammals; if marine mammals 
are observed, Navy personnel must cease detonations or fuse initiation. 
While performing their normal duties during the activity, divers must 
observe the underwater detonation location for marine mammals. Divers 
must notify their supporting small boat or Range Safety Officer of 
marine mammal sightings at the underwater detonation location; if 
observed, the Navy must cease detonations or fuse initiation. To the 
maximum extent practicable depending on mission requirements, safety, 
and environmental conditions, Navy personnel must position boats near 
the mid-point of the mitigation zone radius (but outside of the 
detonation plume and human safety zone), must position themselves on 
opposite sides of the detonation location (when two boats are used), 
and must travel in a circular pattern around the detonation location 
with one Lookout observing inward toward the detonation site and the 
other observing outward toward the perimeter of the mitigation zone. If 
used, Navy aircraft must travel in a circular pattern around the 
detonation location to the maximum extent practicable. Navy personnel 
must not set time-delay firing devices to exceed 10 min.
    (F) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the underwater detonation location or 
mitigation zone (as applicable) prior to the initial start of the 
activity (by delaying the start) or during the activity (by not 
recommencing detonations or fuse initiation) until one of the following 
conditions has been met: The animal is observed exiting the 500 yd or 
1,000 yd mitigation zone; the animal is thought to have exited the 500 
yd or 1,000 yd mitigation zone based on a determination of its course, 
speed, and movement relative to the detonation site; or the 500 yd or 
1,000 yd mitigation zones (for Lookouts on small boats or aircraft) and 
the underwater detonation location (for divers) has been clear from any 
additional sightings for 10 min during activities under positive 
control with aircraft that have fuel constraints, or 30 min during 
activities under positive control with aircraft that are not typically 
fuel constrained and during activities using time-delay firing devices.
    (G) After completion of an activity, the Navy must observe for 
marine mammals for 30 min. Navy personnel must observe for marine 
mammals in the vicinity of where detonations occurred; if any injured 
or dead marine mammals are observed, Navy personnel must follow 
established incident reporting procedures. If additional platforms are 
supporting this activity (e.g., providing range clearance), Navy 
personnel on these assets must assist in the visual observation of the 
area where detonations occurred.
    (12) Maritime security operations--anti-swimmer grenades--(i) 
Number of Lookouts and observation platform. One Lookout must be 
positioned on the small boat conducting the activity. If additional 
platforms are participating in the activity, Navy personnel positioned 
on those assets (e.g., safety observers, evaluators) must support 
observing the mitigation zone for marine mammals and other applicable 
biological resources while performing their regular duties.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 200 yd around the intended detonation location.
    (B) Prior to the initial start of the activity (e.g., when 
maneuvering on station), Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must relocate or delay the start of detonations.
    (C) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease detonations.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing detonations) until one of the following conditions 
has been 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, speed, and movement relative to the 
intended detonation location; the mitigation zone has been clear from 
any additional sightings for 30 min; or the intended detonation 
location has transited a distance equal to double that of the 
mitigation zone size beyond the location of the last sighting.
    (E) After completion of the activity (e.g., prior to maneuvering 
off station), Navy personnel must, when practical (e.g., when platforms 
are not constrained by fuel restrictions or mission-essential follow-on 
commitments), observe for marine mammals in the vicinity of where 
detonations occurred; if any injured or dead marine mammals are 
observed, Navy personnel must follow established incident reporting 
procedures. If additional platforms are supporting this activity (e.g., 
providing range clearance), Navy personnel on these assets will assist 
in the visual observation of the area where detonations occurred.
    (13) Vessel movement. The mitigation will not be applied if: The 
vessel's safety is threatened; the vessel is restricted in its ability 
to maneuver (e.g., during launching and recovery of aircraft or landing 
craft, during towing activities, when mooring); the vessel is submerged 
or operated autonomously; or if impracticable based on mission 
requirements (e.g., during Amphibious Assault and Amphibious Raid 
exercises).
    (i) Number of Lookouts and observation platform. One Lookout must 
be on the vessel that is underway.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 500 yd around whales.
    (B) The mitigation zone must be 200 yd around all other marine 
mammals (except bow-riding dolphins).
    (C) During the activity. When underway Navy personnel must observe 
the mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must maneuver to maintain distance.
    (iii) Reporting. If a marine mammal vessel strike occurs, Navy 
personnel must follow the established incident reporting procedures.
    (14) Towed in-water devices. Mitigation applies to devices that are 
towed from a manned surface platform or manned aircraft. The mitigation 
will not be applied if the safety of the towing platform or in-water 
device is threatened.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned on a manned towing platform.

[[Page 46416]]

    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 250 yd around marine mammals.
    (B) During the activity (i.e., when towing an in-water device), 
Navy personnel must observe the mitigation zone for marine mammals; if 
marine mammals are observed, Navy personnel must maneuver to maintain 
distance.
    (15) Small-, medium-, and large-caliber non-explosive practice 
munitions. Mitigation applies to activities using a surface target.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned on the platform conducting the activity. Depending on the 
activity, the Lookout could be the same as the one described for 
``Weapons firing noise'' in paragraph (a)(3)(i) of this section.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 200 yd around the intended impact location.
    (B) Prior to the initial start of the activity (e.g., when 
maneuvering on station), Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must relocate or delay the start of firing.
    (C) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease firing.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been 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, speed, and movement relative to the 
intended impact location; the mitigation zone has been clear from any 
additional sightings for 10 min for aircraft-based firing or 30 min for 
vessel-based firing; or for activities using a mobile target, the 
intended impact location has transited a distance equal to double that 
of the mitigation zone size beyond the location of the last sighting.
    (16) Non-explosive missiles and rockets. Aircraft-deployed non-
explosive missiles and rockets. Mitigation applies to activities using 
a surface target.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned in an aircraft.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 900 yd around the intended impact location.
    (B) Prior to the initial start of the activity (e.g., during a fly-
over of the mitigation zone), Navy personnel must observe the 
mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must relocate or delay the start of firing.
    (C) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease firing.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting prior to or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been 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, speed, and movement relative to the 
intended impact location; or the mitigation zone has been clear from 
any additional sightings for 10 min when the activity involves aircraft 
that have fuel constraints, or 30 min when the activity involves 
aircraft that are not typically fuel constrained.
    (17) Non-explosive bombs and mine shapes. Non-explosive bombs and 
non-explosive mine shapes during mine laying activities.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned in an aircraft.
    (ii) Mitigation zone and requirements. (A) The mitigation zone must 
be 1,000 yd around the intended target.
    (B) Prior to the initial start of the activity (e.g., when arriving 
on station), Navy personnel must observe the mitigation zone for marine 
mammals; if marine mammals are observed, Navy personnel must relocate 
or delay the start of bomb deployment or mine laying.
    (C) During the activity (e.g., during approach of the target or 
intended minefield location), Navy personnel must observe the 
mitigation zone for marine mammals and, if marine mammals are observed, 
Navy personnel must cease bomb deployment or mine laying.
    (D) Commencement/recommencement conditions after a marine mammal 
sighting prior to or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing bomb deployment or mine laying) until one of the 
following conditions has been 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, speed, and movement 
relative to the intended target or minefield location; the mitigation 
zone has been clear from any additional sightings for 10 min; or for 
activities using mobile targets, the intended target has transited a 
distance equal to double that of the mitigation zone size beyond the 
location of the last sighting.
    (b) Mitigation areas. In addition to procedural mitigation, Navy 
personnel must implement mitigation measures within mitigation areas to 
avoid or reduce potential impacts on marine mammals.
    (1) Mitigation areas for marine mammals off Saipan in MITT Study 
Area for sonar, explosives, and vessel strikes--(i) Mitigation area 
requirements--(A) Marpi Reef and Chalan Kanoa Reef Geographic 
Mitigation Areas. (1) Navy personnel will conduct a maximum combined 
total of 20 hours annually from December 1 through April 30 of surface 
ship hull-mounted MF1 mid-frequency active sonar during training and 
testing within the Marpi Reef and Chalan Kanoa Reef Geographic 
Mitigation Areas.
    (2) Navy personnel will not use in-water explosives.
    (3) Navy personnel must report the total hours of all active sonar 
use (all bins, by bin) from December 1 through April 30 in these 
geographic mitigation areas in the annual training and testing exercise 
report submitted to NMFS.
    (4) Should national security present a requirement to conduct 
training or testing prohibited by the mitigation requirements in this 
paragraph (b)(1)(i)(A), Navy personnel must obtain permission from the 
appropriate designated Command authority prior to commencement of the 
activity. Navy personnel must provide NMFS with advance notification 
and include relevant information (e.g., sonar hours, explosives use) in 
its annual activity reports submitted to NMFS.
    (B) Marpi Reef and Chalan Kanoa Reef Awareness Notification Message 
Area. (1) Navy personnel must issue a seasonal awareness notification 
message to alert Navy ships and aircraft operating in the Marpi Reef 
and Chalan Kanoa Reef Geographic Mitigation Areas to the possible 
presence of increased concentrations of humpback whales from December 1 
through April 30.

[[Page 46417]]

    (2) To maintain safety of navigation and to avoid interactions with 
large whales during transits, Navy personnel must instruct vessels to 
remain vigilant to the presence of humpback whales that when 
concentrated seasonally, may become vulnerable to vessel strikes.
    (3) Navy personnel must use the information from the awareness 
notification message to assist their visual observation of applicable 
geographic mitigation zones during training and testing activities and 
to aid in the implementation of procedural mitigation.
    (ii) [Reserved]
    (2) Mitigation areas for marine mammals off Guam of the MITT Study 
Area for sonar and explosives--(i) Mitigation area requirements--(A) 
Agat Bay Nearshore Geographic Mitigation Area. (1) Navy personnel will 
not conduct MF1 surface ship hull-mounted mid-frequency active sonar 
year-round.
    (2) Navy personnel will not use in-water explosives year-round.
    (3) Should national security require the use of MF1 surface ship 
hull-mounted mid-frequency active sonar or explosives within the Agat 
Bay Nearshore Geographic Mitigation Area, Navy personnel must obtain 
permission from the appropriate designated Command authority prior to 
commencement of the activity. Navy personnel must provide NMFS with 
advance notification and include the information (e.g., sonar hours, 
explosives usage) in its annual activity reports submitted to NMFS.
    (B) [Reserved]


Sec.  218.95   Requirements for monitoring and reporting.

    (a) Unauthorized take. Navy personnel 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 serious injury or mortality of any marine mammals, or 
in any Level A harassment or Level B harassment of marine mammals not 
identified in this subpart.
    (b) Monitoring and reporting under the LOA. The Navy must conduct 
all monitoring and reporting required under the LOA, including abiding 
by the U.S. Navy's Marine Species Monitoring Program for the MITT Study 
Area. Details on program goals, objectives, project selection process, 
and current projects are available at 
www.navymarinespeciesmonitoring.us.
    (c) Notification of injured, live stranded, or dead marine mammals. 
Navy personnel must consult the Notification and Reporting Plan, which 
sets out notification, reporting, and other requirements when dead, 
injured, or live stranded marine mammals are detected. The Notification 
and Reporting Plan is available at https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-mariana-islands-training-and-testing-mitt.
    (d) Annual MITT Study Area marine species monitoring report. The 
Navy must submit an annual report to NMFS of the MITT Study Area 
monitoring which will be included in a Pacific-wide monitoring report 
including results specific to the MITT Study Area describing the 
implementation and results from the previous calendar year. Data 
collection methods will be standardized across Pacific Range Complexes 
including the MITT, HSTT, NWTT, and Gulf of Alaska (GOA) Study Areas to 
the best extent practicable, to allow for comparison in different 
geographic locations. The report must be submitted to the Director, 
Office of Protected Resources, NMFS, either within three months after 
the end of the calendar year, or within three months after the 
conclusion of the monitoring year, to be determined by the Adaptive 
Management process. NMFS will submit comments or questions on the draft 
monitoring report, if any, within three months of receipt. The report 
will be considered final after the Navy has addressed NMFS' comments, 
or three months after the submittal of the draft if NMFS does not 
provide comments on the draft report. Such a report will describe 
progress of knowledge made with respect to monitoring study questions 
across multiple Navy ranges associated with the ICMP. Similar study 
questions must be treated together so that progress on each topic can 
be summarized across multiple Navy ranges. The report need not include 
analyses and content that does not provide direct assessment of 
cumulative progress on the monitoring study question. This will 
continue to allow the Navy to provide a cohesive monitoring report 
covering multiple ranges (as per ICMP goals), rather than entirely 
separate reports for the MITT, Hawaii-Southern California, Gulf of 
Alaska, and Northwest Training and Testing Study Areas.
    (e) Annual MITT Study Area Training and Testing Exercise Report. 
Each year, the Navy must submit a preliminary report (Quick Look 
Report) detailing the status of authorized sound sources within 21 days 
after the anniversary of the date of issuance of the LOA to the 
Director, Office of Protected Resources, NMFS. The Navy must also 
submit a detailed report (MITT Annual Training and Testing Exercise 
Report) to the Director, Office of Protected Resources, NMFS, within 
three months after the one-year anniversary of the date of issuance of 
the LOA. The MITT Annual Training and Testing Exercise Report can be 
consolidated with other exercise reports from other range complexes in 
the Pacific Ocean for a single Pacific Exercise Report, if desired. 
NMFS will submit comments or questions on the report, if any, within 
one month of receipt. The report will be considered final after the 
Navy has addressed NMFS' comments, or one month after submittal of the 
draft if NMFS does not provide comments on the draft report. The annual 
will contain information on major training exercises (MTEs), Sinking 
Exercise (SINKEX) events, and a summary of all sound sources used 
(total hours or quantity of each bin of sonar or other non-impulsive 
source; total annual number of each type of explosive exercises; and 
total annual expended/detonated rounds (missiles, bombs, sonobuoys, 
etc.) for each explosive bin). The annual report will also contain 
information on sound sources used including within specific mitigation 
reporting areas as described in paragraph (e)(4) of this section. The 
annual report will also contain both the current year's data as well as 
cumulative sonar and explosive use quantity from previous years' 
reports. Additionally, if there were any changes to the sound source 
allowance in a given year, or cumulatively, the report will include a 
discussion of why the change was made and include analysis to support 
how the change did or did not affect the analysis in the 2020 MITT 
FSEIS/OEIS and MMPA final rule. The annual report will also include the 
details regarding specific requirements associated with specific 
mitigation areas. The final annual/close-out report at the conclusion 
of the authorization period (year seven) will serve as the 
comprehensive close-out report and include both the final year annual 
use compared to annual authorization as well as a cumulative seven-year 
annual use compared to seven-year authorization. The detailed reports 
must contain the information identified in paragraphs (e)(1) through 
(6) of this section.
    (1) MTEs. This section of the report must contain the following 
information for MTEs conducted in the MITT Study Area.
    (i) Exercise information for each MTE.
    (A) Exercise designator.
    (B) Date that exercise began and ended.
    (C) Location.
    (D) Number and types of active sonar sources used in exercise.

[[Page 46418]]

    (E) Number and types of passive acoustic sources used in exercise.
    (F) Number and types of vessels, aircraft, and other platforms 
participating in exercise.
    (G) Total hours of all active sonar source operation.
    (H) Total hours of each active sonar source bin.
    (I) Wave height (high, low, and average) during exercise.
    (ii) Individual marine mammal sighting information for each 
sighting in each exercise where mitigation was implemented.
    (A) Date/Time/Location of sighting.
    (B) Species (if not possible, indication of whale or dolphin).
    (C) Number of individuals.
    (D) Initial Detection Sensor (e.g., sonar, Lookout).
    (E) Indication of specific type of platform observation was made 
from (including, for example, what type of surface vessel or testing 
platform).
    (F) Length of time observers maintained visual contact with marine 
mammal.
    (G) Sea state.
    (H) Visibility.
    (I) Sound source in use at the time of sighting.
    (J) Indication of whether the animal was less than 200 yd, 200 to 
500 yd, 500 to 1,000 yd, 1,000 to 2,000 yd, or greater than 2,000 yd 
from sonar source.
    (K) Whether operation of sonar sensor was delayed, or sonar was 
powered or shut down, and how long the delay.
    (L) If source in use was hull-mounted, true bearing of animal from 
the vessel, true direction of vessel's travel, and estimation of 
animal's motion relative to vessel (opening, closing, parallel).
    (M) Lookouts must 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 were 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 
must identify the specific observations that support any conclusions 
the Navy reaches about the effectiveness of the mitigation.
    (2) SINKEXs. This section of the report must include the following 
information for each SINKEX completed that year.
    (i) Exercise information gathered for each SINKEX.
    (A) Location.
    (B) Date and time exercise began and ended.
    (C) Total hours of observation by Lookouts before, during, and 
after exercise.
    (D) Total number and types of explosive source bins detonated.
    (E) Number and types of passive acoustic sources used in exercise.
    (F) Total hours of passive acoustic search time.
    (G) Number and types of vessels, aircraft, and other platforms, 
participating in exercise.
    (H) Wave height in feet (high, low, and average) during exercise.
    (I) Narrative description of sensors and platforms utilized for 
marine mammal detection and timeline illustrating how marine mammal 
detection was conducted.
    (ii) Individual marine mammal observation (by Navy Lookouts) 
information for each sighting where mitigation was implemented.
    (A) Date/Time/Location of sighting.
    (B) Species (if not possible, indicate whale or dolphin).
    (C) Number of individuals.
    (D) Initial detection sensor (e.g., sonar or Lookout).
    (E) Length of time observers maintained visual contact with marine 
mammal.
    (F) Sea state.
    (G) Visibility.
    (H) Whether sighting was before, during, or after detonations/
exercise, and how many minutes before or after.
    (I) Distance of marine mammal from actual detonations (or target 
spot if not yet detonated): Less than 200 yd, 200 to 500 yd, 500 to 
1,000 yd, 1,000 to 2,000 yd, or greater than 2,000 yd.
    (J) Lookouts must 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.), including speed and direction and if 
any calves were present.
    (K) The report must indicate whether explosive detonations were 
delayed, ceased, modified, or not modified due to marine mammal 
presence and for how long.
    (L) If observation occurred while explosives were detonating in the 
water, indicate munition type in use at time of marine mammal 
detection.
    (3) Summary of sources used. This section of the report must 
include the following information summarized from the authorized sound 
sources used in all training and testing events:
    (i) Total annual hours or quantity (per the LOA) of each bin of 
sonar or other transducers; and
    (ii) Total annual expended/detonated ordnance (missiles, bombs, 
sonobuoys, etc.) for each explosive bin.
    (4) Marpi Reef and Chalan Kanoa Reef Geographic Mitigation Areas. 
The Navy must report any active sonar use (all bins, by bin) between 
December 1 and April 30 that occurred as specifically described in 
these areas. Information included in the classified annual reports may 
be used to inform future adaptive management within the MITT Study 
Area.
    (5) Geographic information presentation. The reports must present 
an annual (and seasonal, where practical) depiction of training and 
testing bin usage geographically across the MITT Study Area.
    (6) Sonar exercise notification. The Navy must submit to NMFS 
(contact as specified in the LOA) an electronic report within fifteen 
calendar days after the completion of any MTE indicating:
    (i) Location of the exercise;
    (ii) Beginning and end dates of the exercise; and
    (iii) Type of exercise.
    (f) Final Close-Out Report. The final (year seven) draft annual/
close-out report must be submitted within three months after the 
expiration of this subpart to the Director, Office of Protected 
Resources, NMFS. NMFS must submit comments on the draft close-out 
report, if any, within three months of receipt. The report will be 
considered final after the Navy has addressed NMFS' comments, or three 
months after the submittal of the draft if NMFS does not provide 
comments.


Sec.  218.96  Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to the regulations 
in this subpart, the Navy must apply for and obtain an LOA in 
accordance with Sec.  216.106 of this section.
    (b) An LOA, unless suspended or revoked, may be effective for a 
period of time not to exceed July 30, 2027.
    (c) If an LOA expires prior to July 30, 2027, the Navy may apply 
for and obtain a renewal of the LOA.
    (d) In the event of projected changes to the activity or to 
mitigation, monitoring, or reporting (excluding changes made pursuant 
to the adaptive management provision of Sec.  218.97(c)(1)) required by 
an LOA issued under this subpart, the Navy must apply for and obtain a 
modification of the LOA as described in Sec.  218.97.
    (e) Each LOA will set forth:
    (1) Permissible methods of incidental taking;
    (2) Geographic areas for incidental taking;
    (3) Means of effecting the least practicable adverse impact (i.e.,

[[Page 46419]]

mitigation) on the species of marine mammals and their habitat; and
    (4) Requirements for monitoring and reporting.
    (f) Issuance of the LOA(s) must be based on a determination that 
the level of taking is consistent with the findings made for the total 
taking allowable under the regulations in this subpart.
    (g) Notice of issuance or denial of the LOA(s) will be published in 
the Federal Register within 30 days of a determination.


Sec.  218.97   Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec. Sec.  216.106 of this section and 
218.96 for the activity identified in Sec.  218.90(c) may be renewed or 
modified upon request by the applicant, provided that:
    (1) The planned specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as 
those described and analyzed for the regulations in this subpart 
(excluding changes made pursuant to the adaptive management provision 
in paragraph (c)(1) of this section); and
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA(s) were implemented.
    (b) For LOA modification or renewal requests by the applicant that 
include changes to the activity or to the mitigation, monitoring, or 
reporting measures (excluding changes made pursuant to the adaptive 
management provision in paragraph (c)(1) of this section) 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 planned LOA in the 
Federal Register, including the associated analysis of the change, and 
solicit public comment before issuing the LOA.
    (c) An LOA issued under Sec. Sec.  216.106 of this section and 
218.96 may be modified by NMFS under the following circumstances:
    (1) Adaptive management. After consulting with the Navy regarding 
the practicability of the modifications, NMFS may modify (including 
adding or removing measures) the existing mitigation, monitoring, or 
reporting measures 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, or reporting measures in an LOA 
include:
    (A) Results from the Navy's annual monitoring report and annual 
exercise report from the previous year(s);
    (B) Results from other marine mammal and/or sound research or 
studies;
    (C) Results from specific stranding investigations; or
    (D) Any information that reveals marine mammals may have been taken 
in a manner, extent, or number not authorized by the regulations in 
this subpart or subsequent LOAs.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
will publish a notice of planned 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 of marine 
mammals specified in LOAs issued pursuant to Sec. Sec.  216.106 of this 
section and 218.96, an LOA may be modified without prior notice or 
opportunity for public comment. Notice will be published in the Federal 
Register within thirty days of the action.

[FR Doc. 2020-15651 Filed 7-30-20; 8:45 am]
BILLING CODE 3510-22-P