[Federal Register Volume 85, Number 133 (Friday, July 10, 2020)]
[Rules and Regulations]
[Pages 41780-41904]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-14181]



[[Page 41779]]

Vol. 85

Friday,

No. 133

July 10, 2020

Part IV





Department of Commerce





-----------------------------------------------------------------------





National Oceanic and Atmospheric Administration





-----------------------------------------------------------------------





50 CFR Part 218





Taking and Importing Marine Mammals; Taking Marine Mammals Incidental 
to the U.S. Navy Training and Testing Activities in the Hawaii-Southern 
California Training and Testing Study Area; Final Rule

  Federal Register / Vol. 85, No. 133 / Friday, July 10, 2020 / Rules 
and Regulations  

[[Page 41780]]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 200625-0169]
RIN 0648-BJ06


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to the U.S. Navy Training and Testing Activities in the 
Hawaii-Southern California Training and Testing Study Area

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

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

-----------------------------------------------------------------------

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 Hawaii-Southern California Training 
and Testing (HSTT) Study Area over the course of seven years, 
effectively extending the time period from December 20, 2023, to 
December 20, 2025. In August 2018, the MMPA was amended by the John S. 
McCain National Defense Authorization Act (NDAA) for Fiscal Year 2019 
to allow for seven-year authorizations for military readiness 
activities, as compared to the previously allowed five years. The 
Navy's activities qualify as military readiness activities pursuant to 
the MMPA as amended by the NDAA for Fiscal Year 2004. These 
regulations, which allow for the issuance of Letters of Authorization 
(LOAs) 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 or stocks and their habitat, and establish 
requirements pertaining to the monitoring and reporting of such taking.

DATES: Effective from July 10, 2020, to December 20, 2025.

ADDRESSES: Copies of the Navy's applications, NMFS' proposed rule for 
these regulations, NMFS' proposed and final rules and subsequent LOAs 
for the associated five-year HSTT Study Area regulations, other 
supporting documents cited herein, and a list of the references cited 
in this document 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: Wendy Piniak, 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.), extend 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, in-water detonations, air guns, impact pile 
driving/vibratory extraction, and the movement of vessels throughout 
the HSTT Study Area. The HSTT Study Area is comprised of established 
operating and warning areas across the north-central Pacific Ocean, 
from the mean high tide line in Southern California west to Hawaii and 
the International Date Line. The Study Area includes the at-sea areas 
of three existing range complexes (the Hawaii Range Complex, the 
Southern California (SOCAL) Range Complex, and the Silver Strand 
Training Complex), and overlaps a portion of the Point Mugu Sea Range 
(PMSR). Also included in the Study Area are Navy pierside locations in 
Hawaii and Southern California, Pearl Harbor, San Diego Bay, and the 
transit corridor \1\ on the high seas where sonar training and testing 
may occur.
---------------------------------------------------------------------------

    \1\ Vessel transit corridors are the routes typically used by 
Navy assets to traverse from one area to another. The route depicted 
in Figure 2-1 of the Navy's March 2019 rulemaking/LOA application is 
the shortest route between Hawaii and Southern California, making it 
the quickest and most fuel efficient. The depicted vessel transit 
corridor is notional and may not represent the actual routes used by 
ships and submarines transiting from Southern California to Hawaii 
and back. Actual routes navigated are based on a number of factors 
including, but not limited to, weather, training, and operational 
requirements.
---------------------------------------------------------------------------

    NMFS received an application from the Navy requesting to extend 
NMFS' existing MMPA regulations (50 CFR part 218, subpart H; hereafter 
``2018 HSTT regulations'') that authorize the take of marine mammals 
incidental to Navy training and testing activities conducted in the 
HSTT Study Area to cover seven years of the Navy's activities, instead 
of five. Take is anticipated to occur by Level A harassment and Level B 
harassment as well as a very small number of serious injuries or 
mortalities incidental to the Navy's training and testing activities.
    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

    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 reduce or 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;
     Implementation of a Notification and Reporting Plan (for 
dead, live stranded, or marine mammals struck by a vessel); 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

[[Page 41781]]

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 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 least practicable adverse impact 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 of Request

    On December 27, 2018, NMFS published a five-year final rule 
governing the taking of marine mammals incidental to Navy training and 
testing activities conducted in the HSTT Study Area (83 FR 66846; 
hereafter ``2018 HSTT final rule''). Previously, on August 13, 2018, 
and towards the end of the time period in which NMFS was processing the 
Navy's request for the 2018 regulations, the 2019 NDAA amended the MMPA 
for military readiness activities to allow incidental take regulations 
to be issued for up to seven years instead of the previous five years. 
The Navy's training and testing activities conducted in the HSTT Study 
Area qualify as military readiness activities pursuant to the MMPA, as 
amended by the 2004 NDAA. On March 11, 2019 the Navy submitted an 
application requesting that NMFS extend the 2018 HSTT regulations and 
associated LOAs such that they would cover take incidental to seven 
years of training and testing activities instead of five, extending the 
expiration date from December 20, 2023 to December 20, 2025.
    In its 2019 application, the Navy proposed no changes to the nature 
of the specified activities covered by the 2018 HSTT final rule, the 
level of activity within and between years will be consistent with that 
previously analyzed in the 2018 HSTT final rule, and all activities 
will be conducted within the same boundaries of the HSTT Study Area 
identified in the 2018 HSTT final rule. Therefore, the training and 
testing activities (e.g., equipment and sources used, exercises 
conducted) and the mitigation, monitoring, and nearly all reporting 
measures are identical to those described and analyzed in the 2018 HSTT 
final rule. The only changes included in the Navy's request were to 
conduct those same activities in the same region for an additional two 
years. In its request, the Navy included all information necessary to 
identify the type and amount of incidental take that may occur in the 
two additional years so NMFS could determine whether the analyses and 
conclusions regarding the impacts of the proposed activities on marine 
mammal species and stocks previously reached for five years of 
activities remain applicable for seven years of identical activity.
    The purpose of the Navy's training and testing activities is to 
ensure that the Navy meets its mission mandated by federal law (10 
U.S.C. 8062), which is to maintain, train, and equip combat-ready naval 
forces capable of winning wars, deterring aggression, and maintaining 
freedom of the seas. The Navy executes this responsibility by 
establishing and executing training programs, including at-sea training 
and exercises, and ensuring naval forces have access to the ranges, 
operating areas (OPAREAs), and airspace needed to develop and maintain 
skills for conducting naval activities. The Navy's mission is achieved 
in part by conducting training and testing within the HSTT Study Area.
    The Navy's March 11, 2019, rulemaking and LOA extension application 
(hereafter ``2019 Navy application'') reflects the same compilation of 
training and testing activities presented in the Navy's October 13, 
2017, initial rulemaking and LOA application (hereafter ``2017 Navy 
application'') and the 2018 HSTT regulations that were subsequently 
promulgated, which can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. These activities are deemed by the Navy 
necessary to accomplish military readiness requirements and are 
anticipated to continue into the reasonably foreseeable future. The 
2019 Navy application and this rule cover training and testing 
activities that will occur over seven years, including the five years 
already authorized under the 2018 HSTT regulations, with the 
regulations valid from the publication date of this final rule through 
December 20, 2025.

Summary of the Regulations

    NMFS is extending the incidental take regulations and associated 
LOAs through December 20, 2025, to cover the same Navy activities 
covered by the 2018 HSTT regulations. The 2018 HSTT final rule was 
recently published and its analysis remains current and valid. In its 
2019 application, the Navy proposed no changes to the nature (e.g., 
equipment and sources used, exercises conducted) or level of the 
specified activities within or between years or to the boundaries of 
the HSTT Study Area. The mitigation, monitoring, and nearly all 
reporting measures (described below) will be identical to those 
described and analyzed in the 2018 HSTT final rule. The regulatory 
language included at the end of this final rule, which will be 
published at 50 CFR part 218, subpart H, also is the same as the HSTT 
2018 regulations, except for a small number of technical changes. No 
new information has been received from the

[[Page 41782]]

Navy, or otherwise become available to NMFS, since publication of the 
2018 HSTT final rule that significantly changes the analyses supporting 
the 2018 findings. Where there is any new information pertinent to the 
descriptions, analyses, or findings required to authorize incidental 
take for military readiness activities under MMPA section 101(a)(5)(A), 
that information is provided in the appropriate sections below.
    Because the activities included in the 2019 Navy application have 
not changed and the analyses and findings included in the documents 
provided and produced in support of the recently published 2018 HSTT 
final rule remain current and applicable, this final rule relies 
heavily on and references to the applicable information and analyses in 
those documents. Below is a list of the primary documents referenced in 
this final rule. The list indicates the short name by which the 
document is referenced in this final rule, as well as the full titles 
of the cited documents. All of the documents can be found at: 
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities and http://www.hstteis.com/.
     NMFS June 26, 2018, Hawaii-Southern California Training 
and Testing (HSTT) proposed rule (83 FR 29872; hereafter ``2018 HSTT 
proposed rule'');
     NMFS December 27, 2018, Hawaii-Southern California 
Training and Testing (HSTT) final rule (83 FR 66846; hereafter ``2018 
HSTT final rule'');
     NMFS September 13, 2019, Hawaii-Southern California 
Training and Testing (HSTT) proposed rule (84 FR 48388; hereafter 
``2019 HSTT proposed rule'');
     Navy October 13, 2017, MMPA rulemaking and LOA application 
(hereafter ``2017 Navy application'');
     Navy March 11, 2019, MMPA rulemaking and LOA extension 
application (hereafter ``2019 Navy application''); and
     October 26, 2018, Hawaii-Southern California Training and 
Testing (HSTT) Final Environmental Impact Statement/Overseas 
Environmental Impact Statement (FEIS/OEIS) (hereafter ``2018 HSTT FEIS/
OEIS'').

Description of the Specified Activity

    The Navy requested authorization to take marine mammals incidental 
to conducting training and testing activities. The Navy has determined 
that acoustic and explosives stressors are most likely to result in 
impacts on marine mammals that could rise to the level of harassment. A 
small number of serious injuries or mortalities are also possible from 
vessel strikes or exposure to explosive detonations. Detailed 
descriptions of these activities are provided in Chapter 2 of the 2018 
HSTT FEIS/OEIS and in the 2017 and 2019 Navy applications.

Overview of Training and Testing Activities

    The Navy routinely trains and tests in the HSTT Study Area in 
preparation for national defense missions. Training and testing 
activities and components covered in the 2019 Navy application are 
described in detail in the Overview of Training and Testing Activities 
sections of the 2018 HSTT proposed rule, the 2018 HSTT final rule, and 
Chapter 2 (Description of Proposed Action and Alternatives) of the 2018 
HSTT FEIS/OEIS. Each military training and testing activity described 
meets mandated Fleet requirements to deploy combat-ready forces. The 
Navy proposed no changes to the specified activities described and 
analyzed in the 2018 HSTT final rule. The boundaries of the HSTT Study 
Area (see Figure 2-1 of the 2019 Navy application); the training and 
testing activities (e.g., equipment and sources used, exercises 
conducted); manner of or amount of vessel movement; and standard 
operating procedures presented in this final rule are identical to 
those described and analyzed in the 2018 HSTT final rule.

Dates and Duration

    The specified activities will occur at any time during the seven-
year period of validity of the regulations. The number of training and 
testing activities are described in the Detailed Description of the 
Specified Activities section (Tables 1 through 5).

Geographical Region

    The geographic extent of the HSTT Study Area is identical to that 
described in the 2018 HSTT final rule. The HSTT Study Area (see Figure 
2-1 of the 2019 Navy application) is comprised of established operating 
and warning areas across the north-central Pacific Ocean, from the mean 
high tide line in Southern California west to Hawaii and the 
International Date Line. The Study Area includes the at-sea areas of 
three existing range complexes (the Hawaii Range Complex, the Southern 
California (SOCAL) Range Complex, and the Silver Strand Training 
Complex), and overlaps a portion of the Point Mugu Sea Range (PMSR). 
Also included in the Study Area are Navy pierside locations in Hawaii 
and Southern California, Pearl Harbor, San Diego Bay, and the transit 
corridor \2\ on the high seas where sonar training and testing may 
occur.
---------------------------------------------------------------------------

    \2\ Vessel transit corridors are the routes typically used by 
Navy assets to traverse from one area to another. The route depicted 
in Figure 2-1 of the 2019 Navy application is the shortest route 
between Hawaii and Southern California, making it the quickest and 
most fuel efficient. The depicted vessel transit corridor is 
notional and may not represent the actual routes used by ships and 
submarines transiting from Southern California to Hawaii and back. 
Actual routes navigated are based on a number of factors including, 
but not limited to, weather, training, and operational requirements.
---------------------------------------------------------------------------

    A Navy range complex consists of geographic areas that encompass a 
water component (above and below the surface) and airspace, and may 
encompass a land component where training and testing of military 
platforms, tactics, munitions, explosives, and electronic warfare 
systems occur. Range complexes include established OPAREAs, which may 
be further divided to provide better control of the area for safety 
reasons. Additional detail on range complexes and testing ranges was 
provided in the Duration and Location section of the 2018 HSTT proposed 
rule; please see the 2018 HSTT proposed rule or the 2017 Navy 
application for more information and maps.

Description of Acoustic and Explosive 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 statutory mission. Training and testing with these 
systems may introduce acoustic (sound) energy or shock waves from 
explosives into the environment. The specific components that could act 
as stressors by having direct or indirect impacts on the environment 
are described in detail in the Description of Acoustic and Explosive 
Stressors section of the 2018 HSTT final rule and Chapter 2 
(Description of Proposed Action and Alternatives) of the 2018 HSTT 
FEIS/OEIS. The Navy proposes no changes to the nature of the specified 
activities and, therefore, the acoustic and explosive stressors are 
identical to those described and analyzed in the 2018 HSTT final rule.

Other Stressor--Vessel Strike

    Vessel strikes are not specific to any particular training or 
testing activity, but rather a limited, sporadic, and incidental result 
of Navy vessel movement within the HSTT Study Area. Navy vessels 
transit at speeds that are optimal for fuel conservation or to meet 
training and testing requirements. The average speed of large Navy 
ships ranges between 10 and 15 knots and

[[Page 41783]]

submarines generally operate at speeds in the range of 8 to 13 knots, 
while a few specialized vessels can travel at faster speeds. By 
comparison, this is slower than most commercial vessels where full 
speed for a container ship is typically 24 knots (Bonney and Leach, 
2010), with average vessel speeds along the California coast recently 
reported to be between 14 and 18 knots (Moore et al., 2018).
    Should a vessel strike occur, it would likely result in incidental 
take from serious injury and/or mortality and, accordingly, for the 
purposes of the analysis we assume that any ship strike would result in 
serious injury or mortality. The Navy proposed no changes to the nature 
of the specified activities, the training and testing activities, the 
manner of or amount of vessel movement, or standard operating 
procedures described in the 2018 HSTT final rule. Therefore, the 
description of vessel strikes as a stressor is the same as that 
presented in the Other Stressor--Vessel Strike sections of the 2018 
HSTT proposed rule and 2018 HSTT final rule.

Detailed Description of the Specified Activities

    The Navy's specified activities are presented and analyzed as a 
representative year of training to account for the natural fluctuation 
of training cycles and deployment schedules in any seven-year period. 
In the 2018 HSTT final rule, NMFS analyzed the potential impacts of 
these activities (i.e., incidental take of marine mammals) based on the 
Navy conducting three years of a representative level of activity and 
two years of a maximum level of activity. For the purposes of this 
rulemaking, the Navy presented and NMFS analyzed activities based on 
the additional two years of training and testing consisting of an 
additional one year of a maximum level of activity and one year of a 
representative level of activity consistent with the pattern set forth 
in the 2018 HSTT final rule, the 2018 HSTT FEIS/OEIS, and the 2017 Navy 
application.
Training Activities
    The number of planned training activities that could occur annually 
and the duration of those activities remains identical to those 
presented in Table 4 of the 2018 HSTT final rule, and are not repeated 
here. The number of planned training activities that could occur over 
the seven-year period are presented in Table 1. The table is organized 
according to primary mission areas and includes the activity name, 
associated stressors applicable to these regulations, sound source bin, 
number of proposed activities, and locations of those activities in the 
HSTT Study Area. For further information regarding the primary platform 
used (e.g., ship or aircraft type) see Appendix A (Navy Activity 
Descriptions) of the 2018 HSTT FEIS/OEIS.

               Table 1--Training Activities Analyzed for Seven-Year Period in the HSTT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                                         7-year
 Stressor category   Activity name             Description              Source bin        Location     number of
                                                                                                         events
----------------------------------------------------------------------------------------------------------------
                         Major Training Events--Large Integrated Anti-Submarine Warfare
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Composite        Aircraft carrier and carrier    ASW1, ASW2,      SOCAL..........         18
                     Training Unit    air wing integrates with        ASW3, ASW4,
                     Exercise \1\.    surface and submarine units     ASW5, HF1,
                                      in a challenging multi-threat   LF6, MF1, MF3,
                                      operational environment that    MF4, MF5,
                                      certifies them ready to         MF11, MF12.
                                      deploy.
Acoustic..........  Rim of the       A biennial multinational        ASW2, ASW3,      HRC............          4
                     Pacific          training exercise in which      ASW4, HF1,      SOCAL..........          4
                     Exercise \1\.    navies from Pacific Rim         HF3, HF4, M3,
                                      nations and the United          MF1, MF3, MF4,
                                      Kingdom assemble in Pearl       MF5, MF11.
                                      Harbor, Hawaii, to conduct
                                      training throughout the
                                      Hawaiian Islands in a number
                                      of warfare areas. Marine
                                      mammal systems may be used
                                      during a Rim of the Pacific
                                      exercise. Components of a Rim
                                      of the Pacific exercise, such
                                      as certain mine warfare and
                                      amphibious training, may be
                                      conducted in the Southern
                                      California Range Complex.
----------------------------------------------------------------------------------------------------------------
                         Major Training Events--Medium Integrated Anti-Submarine Warfare
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Fleet Exercise/  Aircraft carrier and carrier    ASW1, ASW2,      HRC............          7
                     Sustainment      air wing integrates with        ASW3, ASW4,     SOCAL..........         35
                     Exercise \1\.    surface and submarine units     HF1, LF6, MF1,
                                      in a challenging multi-threat   MF3, MF4, MF5,
                                      operational environment to      MF11, MF12.
                                      maintain ability to deploy.
Acoustic..........  Undersea         Elements of the anti-submarine  ASW3, ASW4,      HRC............         17
                     Warfare          warfare tracking exercise       HF1, LF6, MF1,
                     Exercise.        combine in this exercise of     MF3, MF4, MF5,
                                      multiple air, surface, and      MF11, MF12.
                                      subsurface units, over a
                                      period of several days.
                                      Sonobuoys are released from
                                      aircraft. Active and passive
                                      sonar used.
----------------------------------------------------------------------------------------------------------------
                Integrated/Coordinated Training--Small Integrated Anti-Submarine Warfare Training
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Navy Undersea    Multiple ships, aircraft, and   ASW3, ASW4,      HRC............          7
                     Warfare          submarines integrate the use    HF1, MF1, MF3,  SOCAL..........         18
                     Training and     of their sensors to search      MF4, MF5.
                     Assessment       for, detect, classify,
                     Course Surface   localize, and track a threat
                     Warfare          submarine in order to launch
                     Advanced         an exercise torpedo.
                     Tactical
                     Training.
----------------------------------------------------------------------------------------------------------------
               Integrated/Coordinated Training--Medium Coordinated Anti-Submarine Warfare Training
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Submarine        Train prospective submarine     ASW3, ASW4,      HRC............         12
                     Commanders       Commanding Officers to          HF1, MF1, MF3,  SOCAL..........         12
                     Course.          operate against surface, air,   MF4, MF5,
                                      and subsurface threats.         TORP1, TORP2.
----------------------------------------------------------------------------------------------------------------

[[Page 41784]]

 
               Integrated/Coordinated Training--Small Coordinated Anti-Submarine Warfare Training
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Amphibious       Small-scale, short duration,    ASW2, ASW3,      HRC............         14
                     Ready Group/     coordinated anti-submarine      ASW4, HF1,      SOCAL..........         86
                     Marine           warfare exercises.              MF1, MF3, MF4,
                     Expeditionary                                    MF5, MF11.
                     Unit Exercise
                     Group Sail
                     Independent
                     Deployer
                     Certification
                     Exercise/
                     Tailored Anti-
                     Submarine
                     Warfare
                     Training.
----------------------------------------------------------------------------------------------------------------
                                               Amphibious Warfare
----------------------------------------------------------------------------------------------------------------
Explosive.........  Naval Surface    Surface ship uses large-        Large-caliber    HRC (W188).....        105
                     Fire Support     caliber gun to support forces   HE rounds (E5).
                     Exercise--at     ashore; however, land target
                     Sea.             simulated at sea. Rounds
                                      impact water and are scored
                                      by passive acoustic
                                      hydrophones located at or
                                      near target area.
Acoustic..........  Amphibious       Navy and Marine Corps forces    ASW2, ASW3,      SOCAL..........         18
                     Marine           conduct advanced integration    ASW4, HF1,
                     Expeditionary    training in preparation for     MF1, MF3, MF4,
                     Unit Exercise.   deployment certification.       MF5, MF11.
Acoustic..........  Amphibious       Navy and Marine Corps forces    ASW2, ASW3,      SOCAL..........         18
                     Marine           conduct integration training    ASW4, HF1,
                     Expeditionary    at sea in preparation for       MF1, MF3, MF4,
                     Unit             deployment certification.       MF5, MF11.
                     Integration
                     Exercise.
Acoustic..........  Marine           Amphibious Ready Group          ASW2, ASW3,      SOCAL..........         18
                     Expeditionary    exercises are conducted to      ASW4, HF1,
                     Unit Composite   validate the Marine             MF1, MF3, MF4,
                     Training Unit    Expeditionary Unit's            MF5, MF11.
                     Exercise.        readiness for deployment and
                                      includes small boat raids;
                                      visit, board, search, and
                                      seizure training; helicopter
                                      and mechanized amphibious
                                      raids; and a non-combatant
                                      evacuation operation.
----------------------------------------------------------------------------------------------------------------
                                             Anti-Submarine Warfare
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Anti-Submarine   Helicopter crews search for,    MF4, MF5, TORP1  HRC............         42
                     Warfare          track, and detect submarines.                   SOCAL..........        728
                     Torpedo          Recoverable air launched
                     Exercise--Heli   torpedoes are employed
                     copter.          against submarine targets.
Acoustic..........  Anti-Submarine   Maritime patrol aircraft crews  MF5, TORP1.....  HRC............         70
                     Warfare          search for, track, and detect                   SOCAL..........        175
                     Torpedo          submarines. Recoverable air
                     Exercise--Mari   launched torpedoes are
                     time Patrol      employed against submarine
                     Aircraft.        targets.
Acoustic..........  Anti-Submarine   Surface ship crews search for,  ASW3, MF1,       HRC............        350
                     Warfare          track, and detect submarines.   TORP1.          SOCAL..........        819
                     Torpedo          Exercise torpedoes are used
                     Exercise--Ship.  during this event.
Acoustic..........  Anti-Submarine   Submarine crews search for,     ASW4, HF1, MF3,  HRC............        336
                     Warfare          track, and detect submarines.   TORP2.          SOCAL..........         91
                     Torpedo          Exercise torpedoes are used
                     Exercise--Subm   during this event.
                     arine.
Acoustic..........  Anti-Submarine   Helicopter crews search for,    MF4, MF5.......  HRC............      1,113
                     Warfare          track, and detect submarines.                   SOCAL, PMSR....      3,668
                     Tracking                                                         HSTT Transit            42
                     Exercise--Heli                                                    Corridor.
                     copter.
Acoustic..........  Anti-Submarine   Maritime patrol aircraft        MF5............  HRC............        182
                     Warfare          aircrews search for, track,                     SOCAL, PMSR....        350
                     Tracking         and detect submarines.
                     Exercise--Mari   Recoverable air launched
                     time Patrol      torpedoes are employed
                     Aircraft.        against submarine targets.
Acoustic..........  Anti-Submarine   Surface ship crews search for,  ASW3, MF1,       HRC............      1,568
                     Warfare          track, and detect submarines.   MF11, MF12.     SOCAL, PMSR....      2,961
                     Tracking
                     Exercise--Ship.
Acoustic..........  Anti-Submarine   Submarine crews search for,     ASW4, HF1, HF3,  HRC............      1,400
                     Warfare          track, and detect submarines.   MF3.            SOCAL, PMSR....        350
                     Tracking                                                         HSTT Transit            49
                     Exercise--Subm                                                    Corridor.
                     arine.
Explosive,          Service Weapons  Air, surface, or submarine      HF1, MF3, MF6,   HRC............         14
 Acoustic.           Test.            crews employ explosive          TORP2,          SOCAL..........          7
                                      torpedoes against virtual       Explosive
                                      targets.                        torpedoes
                                                                      (E11).
----------------------------------------------------------------------------------------------------------------
                                                  Mine Warfare
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Airborne Mine    Helicopter aircrews detect      HF4............  SOCAL..........         70
                     Countermeasure   mines using towed or laser
                     -Mine            mine detection systems.
                     Detection.
Explosive,          Civilian Port    Maritime security personnel     HF4, SAS2......  Pearl Harbor,            7
 Acoustic.           Defense--Homel   train to protect civilian      E2, E4.........   HI.                    21
                     and Security     ports against enemy efforts                     San Diego, CA..
                     Anti-Terrorism/  to interfere with access to
                     Force            those ports.
                     Protection
                     Exercises.
Explosive.........  Marine Mammal    The Navy deploys trained        E7.............  HRC............         70
                     Systems.         bottlenose dolphins (Tursiops                   SOCAL..........      1,225
                                      truncatus) and California sea
                                      lions (Zalophus
                                      californianus) as part of the
                                      marine mammal mine-hunting
                                      and object-recovery system.
Acoustic..........  Mine             Ship crews detect and avoid     HF4, HF8, MF1K.  HRC............        210
                     Countermeasure   mines while navigating                          SOCAL..........        664
                     Exercise--Ship   restricted areas or channels
                     Sonar.           using active sonar.
Acoustic..........  Mine             Mine countermeasure ship crews  HF4............  SOCAL..........      1,862
                     Countermeasure   detect, locate, identify, and
                     Exercise--Surf   avoid mines while navigating
                     ace.             restricted areas or channels,
                                      such as while entering or
                                      leaving port.

[[Page 41785]]

 
Explosive,          Mine             Ship, small boat, and           HF4, E4........  HRC............         42
 Acoustic.           Countermeasure   helicopter crews locate and                     SOCAL..........      2,604
                     s Mine           disable mines using remotely
                     Neutralization   operated underwater vehicles.
                     Remotely
                     Operated
                     Vehicle.
Explosive.........  Mine             Personnel disable threat mines  E4, E5, E6, E7.  HRC (Puuloa)...        140
                     Neutralization   using explosive charges.                        SOCAL (IB, TAR       1,358
                     Explosive                                                         2, TAR 3, TAR
                     Ordnance                                                          21, SWAT 3,
                     Disposal.                                                         SOAR).
Acoustic..........  Submarine Mine   Submarine crews practice        HF1............  HRC............        280
                     Exercise.        detecting mines in a                            SOCAL..........         84
                                      designated area.
Acoustic..........  Surface Ship     Ship crews detect and avoid     MF1K, HF8......  HRC............        287
                     Object           mines while navigating                          SOCAL..........      1,134
                     Detection.       restricted areas or channels
                                      using active sonar.
Explosive.........  Underwater       Military personnel use          E10, E13.......  SOCAL (TAR 2,          126
                     Demolitions      explosive charges to destroy                     TAR 3).
                     Multiple         barriers or obstacles to
                     Charge--Mat      amphibious vehicle access to
                     Weave and        beach areas.
                     Obstacle
                     Loading.
Explosive.........  Underwater       Navy divers conduct various     E6, E7.........  HRC (Puuloa)...        203
                     Demolition       levels of training and                          SOCAL (TAR 2)..        700
                     Qualification    certification in placing
                     and              underwater demolition charges.
                     Certification.
----------------------------------------------------------------------------------------------------------------
                                                 Surface Warfare
----------------------------------------------------------------------------------------------------------------
Explosive.........  Bombing          Fixed-wing aircrews deliver     E12 \2\........  HRC............      1,309
                     Exercise Air-    bombs against surface targets.                  SOCAL..........      4,480
                     to-Surface.                                                      HSTT Transit            35
                                                                                       Corridor.
Explosive.........  Gunnery          Small boat crews fire medium-   E1, E2.........  HRC............         70
                     Exercise         caliber guns at surface                         SOCAL..........         98
                     Surface-to-      targets.
                     Surface Boat
                     Medium-Caliber.
Explosive.........  Gunnery          Surface ship crews fire large-  E5.............  HRC............        210
                     Exercise         caliber guns at surface                         SOCAL..........      1,302
                     Surface-to-      targets.                                        HSTT Transit            91
                     Surface Ship                                                      Corridor.
                     Large-caliber.
Explosive.........  Gunnery          Surface ship crews fire medium- E1, E2.........  HRC............        350
                     Exercise         caliber guns at surface                         SOCAL..........      1,260
                     Surface-to-      targets.                                        HSTT Transit           280
                     Surface Ship                                                      Corridor.
                     Medium-Caliber.
Explosive,          Independent      Multiple ships, aircraft and    E1, E3, E6, E10  SOCAL..........          7
 Acoustic.           Deployer         submarines conduct integrated
                     Certification    multi-warfare training with a
                     Exercise/        surface warfare emphasis.
                     Tailored         Serves as a ready-to-deploy
                     Surface          certification for individual
                     Warfare          surface ships tasked with
                     Training.        surface warfare missions.
Explosive.........  Integrated Live  Naval Forces defend against a   E1, E3, E6, E10  HRC (W188A)....          7
                     Fire Exercise.   swarm of surface threats                        SOCAL (SOAR)...          7
                                      (ships or small boats) with
                                      bombs, missiles, rockets, and
                                      small-, medium- and large-
                                      caliber guns.
Explosive.........  Missile          Fixed-wing and helicopter       E6, E8, E10....  HRC............         70
                     Exercise Air-    aircrews fire air-to-surface                    SOCAL..........      1,498
                     to-Surface.      missiles at surface targets.
Explosive.........  Missile          Helicopter aircrews fire both   E3.............  HRC............      1,598
                     Exercise Air-    precision-guided and unguided                   SOCAL..........      1,722
                     to-Surface       rockets at surface targets.
                     Rocket.
Explosive.........  Missile          Surface ship crews defend       E6, E10........  HRC (W188).....        140
                     Exercise         against surface threats                         SOCAL (W291)...         70
                     Surface-to-      (ships or small boats) and
                     Surface.         engage them with missiles.
Explosive,          Sinking          Aircraft, ship, and submarine   TORP2, E5, E10,  HRC............         21
 Acoustic.           Exercise.        crews deliberately sink a       E12.            SOCAL..........          4
                                      seaborne target, usually a
                                      decommissioned ship made
                                      environmentally safe for
                                      sinking according to U.S.
                                      Environmental Protection
                                      Agency standards, with a
                                      variety of munitions.
Pile driving......  Elevated         A pier is constructed off of    Impact hammer    SOCAL..........         14
                     Causeway         the beach. Piles are driven     or vibratory
                     System.          into the bottom with an         extractor.
                                      impact hammer. Piles are
                                      removed from seabed via
                                      vibratory extractor. Only in-
                                      water impacts are analyzed.
----------------------------------------------------------------------------------------------------------------
                                            Other Training Exercises
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Kilo Dip.......  Functional check of the         MF4............  HRC............        420
                                      dipping sonar prior to                          SOCAL..........     16,800
                                      conducting a full test or
                                      training event on the dipping
                                      sonar.
Acoustic..........  Submarine        Submarine crews operate sonar   HF1, MF3.......  Pearl Harbor,        1,540
                     Navigation       for navigation and object                        HI.                   560
                     Exercise.        detection while transiting                      San Diego Bay,
                                      into and out of port during                      CA.
                                      reduced visibility.
Acoustic..........  Submarine Sonar  Maintenance of submarine sonar  MF3............  HRC............      1,820
                     Maintenance      systems is conducted pierside                   Pearl Harbor,        1,820
                     and Systems      or at sea.                                       HI.                   651
                     Checks.                                                          SOCAL..........        644
                                                                                      San Diego Bay,
                                                                                       CA.
                                                                                      HSTT Transit            70
                                                                                       Corridor.

[[Page 41786]]

 
Acoustic..........  Submarine Under- Submarine crews train to        HF1............  HRC............         84
                     Ice              operate under ice. Ice                          SOCAL..........         42
                     Certification.   conditions are simulated
                                      during training and
                                      certification events.
Acoustic..........  Surface Ship     Maintenance of surface ship     HF8, MF1.......  HRC............        525
                     Sonar            sonar systems is conducted                      Pearl Harbor,          560
                     Maintenance      pierside or at sea.                              HI.                 1,750
                     and Systems                                                      SOCAL..........      1,750
                     Checks.                                                          San Diego, CA..         56
                                                                                      HSTT Transit
                                                                                       Corridor.
 
Acoustic..........  Unmanned         Unmanned underwater vehicle     FLS2, M3, SAS2.  HRC............        175
                     Underwater       certification involves                          SOCAL..........         70
                     Vehicle          training with unmanned
                     Training--Cert   platforms to ensure submarine
                     ification and    crew proficiency. Tactical
                     Development.     development involves training
                                      with various payloads for
                                      multiple purposes to ensure
                                      that the systems can be
                                      employed effectively in an
                                      operational environment.
----------------------------------------------------------------------------------------------------------------
Notes: HRC = Hawaii Range Complex, SOCAL = Southern California Range Complex, HSTT = Hawaii-Southern California
  Training and Testing, PMSR = Point Mugu Sea Range Overlap, TAR = Training Area and Range, SOAR = Southern
  California Anti-Submarine Warfare Range, IB = Imperial Beach Minefield.
1. Any non-antisubmarine warfare activity that could occur is captured in the individual activities.
2. For the Bombing Exercise Air-to-Surface, all activities were analyzed using E12 explosive bin, but smaller
  explosives are frequently used.

Testing Activities
    The number of planned testing activities that could occur annually 
and the duration of those activities are identical to those presented 
in Tables 5 through 8 of the 2018 HSTT final rule, and are not repeated 
here. Similar to the 2017 Navy application, the Navy's planned testing 
activities here are based on the level of testing activities 
anticipated to be conducted into the reasonably foreseeable future, 
with adjustments that account for changes in the types and tempo 
(increases or decreases) of testing activities to meet current and 
future military readiness requirements. The number of planned testing 
activities that could occur for the seven-year period are presented in 
Tables 2 through 5.
Naval Air Systems Command
    The Naval Air Systems Command testing activities that could occur 
over the seven-year period within the HSTT Study Area are presented in 
Table 2.

   Table 2--Naval Air Systems Command Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                                         7-year
 Stressor category   Activity name             Description              Source bin        Location     number of
                                                                                                         events
----------------------------------------------------------------------------------------------------------------
                                             Anti-Submarine Warfare
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Anti-Submarine   This event is similar to the    MF5, TORP1.....  HRC............        134
                     Warfare          training event torpedo                          SOCAL..........        353
                     Torpedo Test.    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.
Explosive,          Anti-Submarine   This event is similar to the    MF4, MF5, E3...  SOCAL..........        414
 Acoustic.           Warfare          training event anti-submarine
                     Tracking Test-   tracking exercise-helicopter.
                     Helicopter.      The test evaluates the
                                      sensors and systems used to
                                      detect and track submarines
                                      and to ensure that helicopter
                                      systems used to deploy the
                                      tracking systems perform to
                                      specifications.
Explosive,          Anti-Submarine   The test evaluates the sensors  ASW2, ASW5,      HRC............        399
 Acoustic.           Warfare          and systems used by maritime    MF5, MF6, E1,   SOCAL..........        436
                     Tracking Test-   patrol aircraft to detect and   E3.
                     Maritime         track submarines and to
                     Patrol           ensure that aircraft systems
                     Aircraft.        used to deploy the tracking
                                      systems perform to
                                      specifications and meet
                                      operational requirements.
Explosive,          Sonobuoy Lot     Sonobuoys are deployed from     ASW2, ASW5,      SOCAL..........      1,120
 Acoustic.           Acceptance       surface vessels and aircraft    HF5, HF6, LF4,
                     Test.            to verify the integrity and     MF5, MF6, E1,
                                      performance of a lot or group   E3, E4.
                                      of sonobuoys in advance of
                                      delivery to the fleet for
                                      operational use.
----------------------------------------------------------------------------------------------------------------
                                                  Mine Warfare
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Airborne         A mine-hunting dipping sonar    HF4............  SOCAL..........         24
                     Dipping Sonar    system that is deployed from
                     Minehunting      a helicopter and uses high-
                     Test.            frequency sonar for the
                                      detection and classification
                                      of bottom and moored mines.
Explosive.........  Airborne Mine    A test of the airborne mine     E4.............  SOCAL..........        117
                     Neutralization   neutralization system that
                     System Test.     evaluates the system's
                                      ability to detect and destroy
                                      mines from an airborne mine
                                      countermeasures capable
                                      helicopter (e.g., MH-60). The
                                      airborne mine neutralization
                                      system uses up to four
                                      unmanned underwater vehicles
                                      equipped with high-frequency
                                      sonar, video cameras, and
                                      explosive and non-explosive
                                      neutralizers.

[[Page 41787]]

 
Acoustic..........  Airborne         A mine-hunting system made up   HF6............  SOCAL..........         33
                     Sonobuoy         of sonobuoys deployed from a
                     Minehunting      helicopter. A field of
                     Test.            sonobuoys, using high-
                                      frequency sonar, is used for
                                      detection and classification
                                      of bottom and moored mines.
----------------------------------------------------------------------------------------------------------------
                                                 Surface Warfare
----------------------------------------------------------------------------------------------------------------
Explosive.........  Air-to-Surface   This event is similar to the    E9.............  HRC............         56
                     Bombing Test.    training event bombing                          SOCAL..........         98
                                      exercise air-to-surface.
                                      Fixed-wing aircraft test the
                                      delivery of bombs against
                                      surface maritime targets with
                                      the goal of evaluating the
                                      bomb, the bomb carry and
                                      delivery system, and any
                                      associated systems that may
                                      have been newly developed or
                                      enhanced.
Explosive.........  Air-to-Surface   This event is similar to the    E1.............  HRC............         35
                     Gunnery Test.    training event gunnery                          SOCAL..........        330
                                      exercise air-to-surface.
                                      Fixed-wing and rotary-wing
                                      aircrews evaluate new or
                                      enhanced aircraft guns
                                      against surface maritime
                                      targets to test that the gun,
                                      gun ammunition, or associated
                                      systems meet required
                                      specifications or to train
                                      aircrew in the operation of a
                                      new or enhanced weapons
                                      system.
Explosive.........  Air-to-Surface   This event is similar to the    E6, E9, E10....  HRC............        126
                     Missile Test.    training event missile                          SOCAL..........        384
                                      exercise air-to-surface. Test
                                      may involve both fixed-wing
                                      and rotary-wing aircraft
                                      launching missiles at surface
                                      maritime targets to evaluate
                                      the weapons system or as part
                                      of another systems
                                      integration test.
Explosive.........  Rocket Test....  Rocket tests are conducted to   E3.............  HRC............         14
                                      evaluate the integration,                       SOCAL..........        142
                                      accuracy, performance, and
                                      safe separation of guided and
                                      unguided 2.75-inch rockets
                                      fired from a hovering or
                                      forward flying helicopter or
                                      tilt rotor aircraft.
----------------------------------------------------------------------------------------------------------------
                                            Other Testing Activities
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Kilo Dip.......  Functional check of a           MF4............  SOCAL..........         12
                                      helicopter deployed dipping
                                      sonar system (e.g., AN/AQS-
                                      22) prior to conducting a
                                      testing or training event
                                      using the dipping sonar
                                      system.
Acoustic..........  Undersea Range   Post installation node survey   MF9............  HRC............        129
                     System Test.     and test and periodic testing
                                      of range node transmit
                                      functionality.
----------------------------------------------------------------------------------------------------------------
Notes: HRC = Hawaii Range Complex, SOCAL = Southern California Range Complex.

Naval Sea Systems Command
    The Naval Sea Systems Command testing activities that could occur 
over the seven-year period within the HSTT Study Area are presented in 
Table 3.

   Table 3--Naval Sea Systems Command Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                                         7-year
 Stressor category   Activity name             Description              Source bin        Location     number of
                                                                                                         events
----------------------------------------------------------------------------------------------------------------
                                             Anti-Submarine Warfare
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Anti-Submarine   Ships and their supporting      ASW1, ASW2,      HRC............        154
                     Warfare          platforms (e.g., rotary-wing    ASW3, ASW5,     SOCAL..........        161
                     Mission          aircraft and unmanned aerial    MF1, MF4, MF5,
                     Package          systems) detect, localize,      MF12, TORP1.
                     Testing.         and prosecute submarines.
Acoustic..........  At-Sea Sonar     At-sea testing to ensure        ASW3, ASW4,      HRC............        109
                     Testing.         systems are fully functional    HF1, LF4, LF5,  HRC--SOCAL.....          7
                                      in an open ocean environment.   M3, MF1, MF1K,  SOCAL..........        138
                                                                      MF2, MF3, MF5,
                                                                      MF9, MF10,
                                                                      MF11.
Acoustic..........  Countermeasure   Countermeasure testing          ASW3, ASW4,      HRC............         56
                     Testing.         involves the testing of         HF5, TORP1,     HRC--SOCAL.....         28
                                      systems that will detect,       TORP2.          SOCAL..........         77
                                      localize, and track incoming                    HSTT Transit            14
                                      weapons, including marine                        Corridor.
                                      vessel targets. Testing
                                      includes surface ship torpedo
                                      defense systems and marine
                                      vessel stopping payloads.
Acoustic..........  Pierside Sonar   Pierside testing to ensure      HF1, HF3, HF8,   Pearl Harbor,           49
                     Testing.         systems are fully functional    M3, MF1, MF3,    HI.                    49
                                      in a controlled pierside        MF9.            San Diego, CA..
                                      environment prior to at-sea
                                      test activities.
Acoustic..........  Submarine Sonar  Pierside and at-sea testing of  HF1, HF3, M3,    HRC............         28
                     Testing/         submarine systems occurs        MF3.            Pearl Harbor,          119
                     Maintenance.     periodically following major                     HI.                   168
                                      maintenance periods and for                     San Diego, CA..
                                      routine maintenance.
Acoustic..........  Surface Ship     Pierside and at-sea testing of  ASW3, MF1,       HRC............         21
                     Sonar Testing/   ship systems occurs             MF1K, MF9,      Pearl Harbor,           21
                     Maintenance.     periodically following major    MF10.            HI.                    21
                                      maintenance periods and for                     San Diego, CA..         21
                                      routine maintenance.                            SOCAL..........

[[Page 41788]]

 
Explosive,          Torpedo          Air, surface, or submarine      ASW3, HF1, HF5,  HRC (W188).....         56
 Acoustic.           (Explosive)      crews employ explosive and      HF6, MF1, MF3,  HRC (W188)              21
                     Testing.         non-explosive torpedoes         MF4, MF5, MF6,   SOCAL.          .........
                                      against artificial targets.     TORP1, TORP2,   SOCAL..........         56
                                                                      E8, E11.
Acoustic..........  Torpedo (Non-    Air, surface, or submarine      ASW3, ASW4,      HRC............         56
                     Explosive)       crews employ non-explosive      HF1, HF6, M3,   HRC SOCAL......         63
                     Testing.         torpedoes against submarines    MF1, MF3, MF4,  SOCAL..........         56
                                      or surface vessels.             MF5, MF6,
                                                                      TORP1, TORP2,
                                                                      TORP3.
----------------------------------------------------------------------------------------------------------------
                                                  Mine Warfare
----------------------------------------------------------------------------------------------------------------
Explosive,          Mine             Air, surface, and subsurface    HF4, E4........  SOCAL..........         70
 Acoustic.           Countermeasure   vessels neutralize threat
                     and              mines and mine-like objects.
                     Neutralization
                     Testing.
Explosive,          Mine             Vessels and associated          HF4, SAS2, E4..  HRC............        118
 Acoustic.           Countermeasure   aircraft conduct mine                           SOCAL..........        406
                     Mission          countermeasure operations.
                     Package
                     Testing.
Acoustic..........  Mine Detection   Air, surface, and subsurface    HF1, HF8, MF1,   HRC............         14
                     and              vessels detect and classify     MF5.            HRC SOCAL......         10
                     Classification   mines and mine-like objects.                    SOCAL..........         77
                     Testing.         Vessels also assess their
                                      potential susceptibility to
                                      mines and mine-like objects.
----------------------------------------------------------------------------------------------------------------
                                                 Surface Warfare
----------------------------------------------------------------------------------------------------------------
Explosive.........  Gun Testing--    Surface crews defend against    E3.............  HRC............         49
                     Large-Caliber.   surface targets with large-                     HRC--SOCAL.....        504
                                      caliber guns.                                   SOCAL..........         49
Explosive.........  Gun Testing--    Surface crews defend against    E1.............  HRC............         28
                     Medium-Caliber.  surface targets with medium-                    HRC--SOCAL.....        336
                                      caliber guns.                                   SOCAL..........         28
Explosive.........  Missile and      Missile and rocket testing      E6.............  HRC............         91
                     Rocket Testing.  includes various missiles or                    HRC--SOCAL.....        168
                                      rockets fired from submarines                   SOCAL..........        140
                                      and surface combatants.
                                      Testing of the launching
                                      system and ship defense is
                                      performed.
----------------------------------------------------------------------------------------------------------------
                                                Unmanned Systems
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Unmanned         Testing involves the            HF4, SAS2......  HRC............         21
                     Surface          production or upgrade of                        SOCAL..........         28
                     Vehicle System   unmanned surface vehicles.
                     Testing.         This may include tests of
                                      mine detection capabilities,
                                      evaluations of the basic
                                      functions of individual
                                      platforms, or complex events
                                      with multiple vehicles.
Acoustic..........  Unmanned         Testing involves the            HF4, MF9.......  HRC............         21
                     Underwater       production or upgrade of                        SOCAL..........      2,037
                     Vehicle          unmanned underwater vehicles.
                     Testing.         This may include tests of
                                      mine detection capabilities,
                                      evaluations of the basic
                                      functions of individual
                                      platforms, or complex events
                                      with multiple vehicles.
----------------------------------------------------------------------------------------------------------------
                                                Vessel Evaluation
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Submarine Sea    Submarine weapons and sonar     HF1, M3, MF3,    HRC............          7
                     Trials--Weapon   systems are tested at-sea to    MF9, MF10,      SOCAL..........          7
                     s System         meet the integrated combat      TORP2.
                     Testing.         system certification
                                      requirements.
Explosive.........  Surface Warfare  Tests the capabilities of       E1, E5, E8.....  HRC............         63
                     Testing.         shipboard sensors to detect,                    HRC--SOCAL.....        441
                                      track, and engage surface                       SOCAL..........        102
                                      targets. Testing may include
                                      ships defending against
                                      surface targets using
                                      explosive and non-explosive
                                      rounds, gun system structural
                                      test firing, and
                                      demonstration of the response
                                      to Call for Fire against land-
                                      based targets (simulated by
                                      sea-based locations).
Acoustic..........  Undersea         Ships demonstrate capability    ASW4, HF4, HF8,  HRC............         49
                     Warfare          of countermeasure systems and   MF1, MF4, MF5,  HRC SOCAL\.....         60
                     Testing.         underwater surveillance,        MF6, TORP1,     SOCAL..........         69
                                      weapons engagement, and         TORP2.
                                      communications systems. This
                                      tests ships ability to
                                      detect, track, and engage
                                      undersea targets.
Acoustic..........  Vessel           Surface ship, submarine and     ASW3...........  HRC............         28
                     Signature        auxiliary system signature                      HRC SOCAL......        252
                     Evaluation.      assessments. This may include                   SOCAL..........        168
                                      electronic, radar, acoustic,
                                      infrared and magnetic
                                      signatures.
----------------------------------------------------------------------------------------------------------------
                                            Other Testing Activities
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Insertion/       Testing of submersibles         M3, MF9........  HRC............          7
                     Extraction.      capable of inserting and                        SOCAL..........          7
                                      extracting personnel and
                                      payloads into denied areas
                                      from strategic distances.
Acoustic..........  Signature        Surface ship and submarine      HF1, M3, MF9...  HRC............         14
                     Analysis         testing of electromagnetic,                     SOCAL..........          7
                     Operations.      acoustic, optical, and radar
                                      signature measurements.
----------------------------------------------------------------------------------------------------------------
Notes: HRC = Hawaii Range Complex, SOCAL = Southern California Range Complex, HSTT = Hawaii-Southern California
  Training and Testing, CA = California, HI = Hawaii.


[[Page 41789]]

Office of Naval Research
    The Office of Naval Research testing activities that could occur 
over the seven-year period within the HSTT Study Area are presented in 
Table 4.

   Table 4--Office of Naval Research Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                                         7-year
 Stressor category   Activity name             Description              Source bin        Location     number of
                                                                                                         events
----------------------------------------------------------------------------------------------------------------
                                Acoustic and Oceanographic Science and Technology
----------------------------------------------------------------------------------------------------------------
Explosive,          Acoustic and     Research using active           AG, ASW2, BB4,   HRC............         14
 Acoustic.           Oceanographic    transmissions from sources      BB9, LF3, LF4,  SOCAL..........         28
                     Research.        deployed from ships and         LF5, MF8, MF9,
                                      unmanned underwater vehicles.   MF9, MF9, E3.
                                      Research sources can be used
                                      as proxies for current and
                                      future Navy systems.
Acoustic..........  Long Range       Bottom mounted acoustic source  LF4............  HRC............         21
                     Acoustic         off of the Hawaiian Island of
                     Communications.  Kauai will transmit a variety
                                      of acoustic communications
                                      sequences.
----------------------------------------------------------------------------------------------------------------
Notes: HRC = Hawaii Range Complex, SOCAL = Southern California Range Complex.

Naval Information Warfare Systems Command
    The Naval Information Warfare Systems Command testing activities 
that could occur over the seven-year period within the HSTT Study Area 
are presented in Table 5.

Table 5--Naval Information Warfare Systems Command Testing Activities Analyzed for Seven-Year Period in the HSTT
                                                   Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                                         7-year
 Stressor category   Activity name             Description              Source bin        Location     number of
                                                                                                         events
----------------------------------------------------------------------------------------------------------------
Acoustic..........  Anti-Terrorism/  Testing sensor systems that     SD1............  San Diego, CA..         98
                     Force            can detect threats to naval                     SOCAL..........        112
                     Protection.      piers, ships, and shore
                                      infrastructure.
Acoustic..........  Communications.  Testing of underwater           ASW2, ASW5,      HRC............          5
                                      communications and networks     HF6, LF4.       SOCAL..........         70
                                      to extend the principles of
                                      FORCEnet below the ocean
                                      surface.
Acoustic..........  Energy and       Develop, integrate, and         AG, HF2, HF7,    HRC............         87
                     Intelligence,    demonstrate Intelligence,       LF4, LF5, LF6,  SOCAL..........        357
                     Surveillance,    Surveillance, and               MF10.           HSTT Transit            56
                     and              Reconnaissance systems and in-                   Corridor.
                     Reconnaissance   situ energy systems to
                     Sensor Systems.  support deployed systems.
Acoustic..........  Vehicle Testing  Testing of surface and          BB4, FLS2,       HRC............          8
                                      subsurface vehicles and         FLS3, HF6,      SOCAL..........      1,141
                                      sensor systems that may         LF3, M3, MF9,   HSTT Transit            14
                                      involve Unmanned Underwater     MF13, SAS1,      Corridor.
                                      Vehicles, gliders, and          SAS2, SAS3.
                                      Unmanned Surface Vehicles.
----------------------------------------------------------------------------------------------------------------
Notes: HRC = Hawaii Range Complex, SOCAL = Southern California Range Complex, HSTT = Hawaii-Southern California
  Training and Testing, CA = California.

Summary of Acoustic and Explosive Sources Analyzed for Training and 
Testing

    Tables 6 through 9 show the acoustic and explosive source classes, 
bins, and numbers used, airgun sources and numbers used, and numbers of 
pile driving and removal activities associated with the Navy's planned 
training and testing activities over a seven-year period in the HSTT 
Study Area that were analyzed in the 2019 Navy application and for this 
final rule. The annual numbers for acoustic source classes, explosive 
source bins, and airgun sources, as well as the annual pile driving and 
removal activities associated with Navy training and testing activities 
in the HSTT Study Area are identical to those presented in Tables 9 
through 12 of the 2018 HSTT final rule, and are not repeated here. 
Consistent with the periodicity in the 2018 HSTT final rule, the Navy 
included the addition of two pile driving/extraction activities for 
each of the two additional years.
    Table 6 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 would vary annually. 
The seven-year totals for the planned training and testing activities 
take into account that annual variability.

    Table 6--Acoustic Source Classes Analyzed and Number Used for Seven-Year Period for Training and Testing
                                        Activities in the HSTT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                     Training         Testing
      Source class category              Bin            Description     Unit \1\ -------------------------------
                                                                                   7-year total    7-year total
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF): Sources that  LF3.............  LF sources greater  H.......               0           1,365
 produce signals less than 1 kHz.                    than 200 dB.

[[Page 41790]]

 
                                  LF4.............  LF sources equal    H.......               0           4,496
                                                     to 180 dB and up   C.......               0             140
                                                     to 200 dB.
                                  LF5.............  LF sources less     H.......              65          14,458
                                                     than 180 dB.
                                  LF6.............  LF sources greater  H.......             956             360
                                                     than 200 dB with
                                                     long pulse
                                                     lengths.
Mid-Frequency (MF): Tactical and  MF1.............  Hull-mounted        H.......          38,489           8,692
 non-tactical sources that                           surface ship
 produce signals between 1 and                       sonars (e.g., AN/
 10 kHz.                                             SQS-53C and AN/
                                                     SQS-61).
                                  MF1K............  Kingfisher mode     H.......             700              98
                                                     associated with
                                                     MF1 sonars.
                                  MF2 \2\.........  Hull-mounted        H.......               0             378
                                                     surface ship
                                                     sonars (e.g., AN/
                                                     SQS-56).
                                  MF3.............  Hull-mounted        H.......          14,700           9,177
                                                     submarine sonars
                                                     (e.g., AN/BQQ-10).
                                  MF4.............  Helicopter-         H.......           2,719           2,502
                                                     deployed dipping
                                                     sonars (e.g., AN/
                                                     AQS-22 and AN/AQS-
                                                     13).
                                  MF5.............  Active acoustic     C.......          40,128          38,233
                                                     sonobuoys (e.g.,
                                                     DICASS).
                                  MF6.............  Active underwater   C.......              63           8,202
                                                     sound signal
                                                     devices (e.g., MK
                                                     84).
                                  MF8.............  Active sources      H.......               0             490
                                                     (greater than 200
                                                     dB) not otherwise
                                                     binned.
                                  MF9.............  Active sources      H.......               0          36,056
                                                     (equal to 180 dB
                                                     and up to 200 dB)
                                                     not otherwise
                                                     binned.
                                  MF10............  Active sources      H.......               0          13,104
                                                     (greater than 160
                                                     dB, but less than
                                                     180 dB) not
                                                     otherwise binned.
                                  MF11............  Hull-mounted        H.......           5,205             392
                                                     surface ship
                                                     sonars with an
                                                     active duty cycle
                                                     greater than 80%.
                                  MF12............  Towed array         H.......           1,260           4,620
                                                     surface ship
                                                     sonars with an
                                                     active duty cycle
                                                     greater than 80%.
                                  MF13............  MF sonar source...  H.......               0           2,100
High-Frequency (HF): Tactical     HF1.............  Hull-mounted        H.......          12,550           5,403
 and non-tactical sources that                       submarine sonars
 produce signals between 10 and                      (e.g., AN/BQQ-10).
 100 kHz.
                                  HF2.............  HF Marine Mammal    H.......               0             840
                                                     Monitoring System.
                                  HF3.............  Other hull-mounted  H.......           1,919             769
                                                     submarine sonars
                                                     (classified).
                                  HF4.............  Mine detection,     H.......          15,012         114,069
                                                     classification,
                                                     and
                                                     neutralization
                                                     sonar (e.g., AN/
                                                     SQS-20).
                                  HF5.............  Active sources      H.......               0           6,720
                                                     (greater than 200  C.......               0             280
                                                     dB) not otherwise
                                                     binned.
                                  HF6.............  Active sources      H.......               0           7,015
                                                     (equal to 180 dB
                                                     and up to 200 dB)
                                                     not otherwise
                                                     binned.
                                  HF7.............  Active sources      H.......               0           9,660
                                                     (greater than 160
                                                     dB, but less than
                                                     180 dB) not
                                                     otherwise binned.
                                  HF8.............  Hull-mounted        H.......             711           5,136
                                                     surface ship
                                                     sonars (e.g., AN/
                                                     SQS-61).
Anti-Submarine Warfare (ASW):     ASW1............  MF systems          H.......           1,503           3,290
 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.......           4,824          32,900
                                                     Active Coherent
                                                     sonobuoy (e.g.,
                                                     AN/SSQ-125).
                                  ASW3............  MF towed active     H.......          37,385          19,187
                                                     acoustic
                                                     countermeasure
                                                     systems (e.g., AN/
                                                     SLQ-25).
                                  ASW4............  MF expendable       C.......           9,023          15,398
                                                     active acoustic
                                                     device
                                                     countermeasures
                                                     (e.g., MK 3).
                                  ASW5 \3\........  MF sonobuoys with   H.......           1,780           3,854
                                                     high duty cycles.
Torpedoes (TORP): Source classes  TORP1...........  Lightweight         C.......           1,605           6,454
 associated with the active                          torpedo (e.g., MK
 acoustic signals produced by                        46, MK 54, or
 torpedoes.                                          Anti-Torpedo
                                                     Torpedo).
                                  TORP2...........  Heavyweight         C.......           3,515           2,756
                                                     torpedo (e.g., MK
                                                     48).
                                  TORP3...........                      C.......               0             315
Forward Looking Sonar (FLS):      FLS2............  HF sources with     H.......             196           3,424
 Forward or upward looking                           short pulse
 object avoidance sonars used                        lengths, narrow
 for ship navigation and safety.                     beam widths, and
                                                     focused beam
                                                     patterns.
                                  FLS3............  VHF sources with    H.......               0          18,480
                                                     short pulse
                                                     lengths, narrow
                                                     beam widths, and
                                                     focused beam
                                                     patterns.

[[Page 41791]]

 
Acoustic Modems (M): Systems      M3..............  MF acoustic modems  H.......             274           3,623
 used to transmit data through                       (greater than 190
 the water.                                          dB).
Swimmer Detection Sonars (SD):    SD1-SD2.........  HF and VHF sources  H.......               0              70
 Systems used to detect divers                       with short pulse
 and submerged swimmers.                             lengths, used for
                                                     the detection of
                                                     swimmers and
                                                     other objects for
                                                     the purpose of
                                                     port security.
Synthetic Aperture Sonars (SAS):  SAS1............  MF SAS systems....  H.......               0          13,720
 Sonars in which active acoustic
 signals are post-processed to
 form high-resolution images of
 the seafloor.
                                  SAS2............  HF SAS systems....  H.......           6,297          60,088
                                  SAS3............  VHF SAS systems...  H.......               0          32,200
                                  SAS4............  MF to HF broadband  H.......             294               0
                                                     mine
                                                     countermeasure
                                                     sonar.
Broadband Sound Sources (BB):     BB4.............  LF to MF            H.......               0           6,414
 Sonar systems with large                            oceanographic
 frequency spectra, used for                         source.
 various purposes.
                                  BB7.............  LF oceanographic    C.......               0             196
                                                     source.
                                  BB9.............  MF optoacoustic     H.......               0           3,360
                                                     source.
----------------------------------------------------------------------------------------------------------------
\1\ H = hours; C = count (e.g., number of individual pings or individual sonobuoys).
\2\ MF2/MF2K are sources on frigate class ships, which were decommissioned during Phase II.
\3\ Formerly ASW2 (H) in Phase II.
Notes: dB = decibel(s), kHz = kilohertz, VHF = very high frequency.

    Table 7 describes the number of air gun shots that could occur over 
seven years under the planned training and testing activities.

          Table 7--Training and Testing Air Gun Sources Quantitatively Analyzed in the HSTT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                     Training         Testing
        Source class category                  Bin                Unit \1\       -------------------------------
                                                                                   7-year total    7-year total
----------------------------------------------------------------------------------------------------------------
Air Guns (AG): Small underwater air   AG..................  C...................               0           5,908
 guns.
----------------------------------------------------------------------------------------------------------------
\1\ C = count. One count (C) of AG is equivalent to 100 air gun firings.

    Table 8 summarizes the impact pile driving and vibratory pile 
removal activities that could occur during a 24-hour period. Annually, 
for impact pile driving, the Navy will drive 119 piles, two times a 
year for a total of 238 piles. Over the seven-year period of the rule, 
the Navy will drive a total of 1,666 piles by impact pile driving. 
Annually, for vibratory pile extraction, the Navy will extract 119 
piles, two times a year for a total of 238 piles. Over the seven-year 
period of the rule, the Navy will extract a total of 1,666 piles by 
vibratory pile extraction.

        Table 8--Summary of Pile Driving and Removal Activities per 24-Hour Period in the HSTT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                                       Total
                                                                                                  estimated time
                             Method                                Piles per 24-   Time per pile   of noise per
                                                                    hour period      (minutes)    24-hour period
                                                                                                     (minutes)
----------------------------------------------------------------------------------------------------------------
Pile Driving (Impact)...........................................               6              15              90
Pile Removal (Vibratory)........................................              12               6              72
----------------------------------------------------------------------------------------------------------------

    Table 9 describes the number of in-water explosives that could be 
used in any year under the proposed training and testing activities. 
Under the proposed activities bin use would vary annually, and the 
seven-year totals for the planned training and testing activities take 
into account that annual variability.

[[Page 41792]]



     Table 9--Explosive Source Bins Analyzed and Number Used for Seven-Year Period for Training and Testing
                                      Activities Within the HSTT Study Area
----------------------------------------------------------------------------------------------------------------
                                                                      Modeled        Training         Testing
                         Net explosive                              underwater   -------------------------------
          Bin            weight (lb.)   Example explosive source    detonation
                              \1\                                  depths (ft.)    7-year total    7-year total
----------------------------------------------------------------------------------------------------------------
E1....................        0.1-0.25  Medium-caliber                   0.3, 60          20,580          87,012
                                         projectiles.
E2....................       >0.25-0.5  Medium-caliber                   0.3, 50          12,222               0
                                         projectiles.
E3....................        >0.5-2.5  Large-caliber                    0.3, 60          19,579          20,848
                                         projectiles.
E4....................          >2.5-5  Mine neutralization          10, 16, 33,             266           4,372
                                         charge.                     50, 61, 65,
                                                                             650
E5....................           >5-10  5 in projectiles........     0.3, 10, 50          33,310           9,800
E6....................          >10-20  Hellfire missile........    0.3, 10, 50,           4,056             230
                                                                              60
E7....................          >20-60  Demo block/.............      10, 50, 60              91               0
                                        shaped charge...........
E8....................         >60-100  Lightweight torpedo.....        0.3, 150             241             399
E9....................        >100-250  500 lb bomb.............             0.3           2,950              28
E10...................        >250-500  Harpoon missile.........             0.3           1,543             210
E11...................        >500-650  650 lb mine.............         61, 150              69              84
E12...................      >650-1,000  2,000 lb bomb...........             0.3             114               0
E13...................    >1,000-1,740  Multiple Mat Weave                NA \2\              63               0
                                         charges.
----------------------------------------------------------------------------------------------------------------
\1\ Net Explosive Weight refers to the amount of explosives; the actual weight of a munition may be larger due
  to other components.
\2\ Not modeled because charge is detonated in surf zone; not a single E13 charge, but multiple smaller charges
  detonated in quick succession.
Notes: in. = inch(es), lb. = pound(s), ft. = feet.

Vessel Movement

    Vessels used as part of the planned activities include ships, 
submarines, unmanned vessels, and boats ranging in size from small, 22 
ft (7 m) rigid hull inflatable boats to aircraft carriers with lengths 
up to 1,092 ft (333 m). The average speed of large Navy ships ranges 
between 10 and 15 knots and submarines generally operate at speeds in 
the range of 8-13 knots (kn), while a few specialized vessels can 
travel at faster speeds. Small craft (for purposes of this analysis, 
less than 18 m in length) have much more variable speeds (0-50+ kn, 
dependent on the activity), but generally range from 10 to 14 kn. From 
unpublished Navy data, average median speed for large Navy ships in the 
HSTT Study Area from 2011-2015 varied from 5-10 kn with variations by 
ship class and location (i.e., slower speeds close to the coast). While 
these speeds for large and small craft are representative of most 
events, some vessels need to temporarily operate outside of these 
parameters. A full description of Navy vessels that are used during 
training and testing activities can be found in the 2017 Navy 
application and Chapter 2 (Description of Proposed Action and 
Alternatives) of the 2018 HSTT FEIS/OEIS.
    The number of Navy vessels used in the HSTT Study Area varies based 
on military training and testing requirements, deployment schedules, 
annual budgets, and other dynamic factors. Most training and testing 
activities involve the use of vessels. These activities could be widely 
dispersed throughout the HSTT Study Area, but would typically be 
conducted near naval ports, piers, and range areas. Navy vessel traffic 
will be especially concentrated near San Diego, California and Pearl 
Harbor, Hawaii. There is no seasonal differentiation in Navy vessel use 
because of continual operational requirements from Combatant 
Commanders. The majority of large vessel traffic occurs between the 
installations and the OPAREAs. Support craft will be more concentrated 
in the coastal waters in the areas of naval installations, ports, and 
ranges. Activities involving vessel movements occur intermittently and 
are variable in duration, ranging from a few hours up to weeks.
    The manner in which Navy vessels will be used during training and 
testing activities, the speeds at which they operate, the number of 
vessels that will be used during various activities, and the locations 
in which Navy vessel movement will be concentrated within the HSTT 
Study Area have not changed from those analyzed in the 2018 HSTT final 
rule. The only change related to the Navy's request regarding Navy 
vessel movement is the vessel use associated with the additional two 
years of Navy activities.

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 a real-world situation 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 activities and included them in the environmental analysis. 
Details on standard operating procedures were provided in the 2018 HSTT 
proposed rule; please see the 2018 HSTT proposed rule, the 2017 Navy 
application, and Chapter 2 (Description of Proposed Action and 
Alternatives) of the 2018 HSTT FEIS/OEIS for more information. The 
Standard Operating Procedures for the seven-year period will be 
identical to those in place under the 2018 HSTT final rule.

Comments and Responses

    On May 8, 2019, we published a notice of receipt (NOR) in the 
Federal Register (84 FR 20105) for the Navy's application to 
effectively extend the five-year 2018 HSTT regulations to seven years, 
and requested comments and information related to the Navy's request. 
The review and comment period for the NOR ended on June 7, 2019. We 
reviewed and considered all comments and information received on the 
NOR in development of the proposed rule. We published the proposed 
seven-year rule for the Navy's HSTT activities in the Federal Register 
on September 13, 2019 (83 FR 48388),

[[Page 41793]]

with a 30-day comment period. In that proposed rule, we requested 
public input on the request for authorization described therein, our 
analyses, and the proposed authorizations and requested that interested 
persons submit relevant information, suggestions, and comments. During 
the 30-day comment period, we received 30 comment letters. Of this 
total, one submission was from the Marine Mammal Commission (hereafter 
``Commission''), two letters were from organizations or individuals 
acting in an official capacity (e.g., non-governmental organizations 
(NGOs)) and 27 submissions were from private citizens. Both the 
Commission and NGOs included their comments submitted on the 2018 HSTT 
proposed five-year rule, which the seven-year rule here is nearly 
identical to. The Commission did not reiterate their 2018 HSTT proposed 
rule recommendations in their comment letter but maintained that the 
recommendations that NMFS did not incorporate into the 2018 HSTT final 
rule are still relevant and pertain to the extension of the five-year 
rule and asked that they be reviewed again in the course of considering 
the new seven-year rule. One letter from NGOs attached their 2018 HSTT 
proposed rule comment letter. They stated that ``most of the issues 
raised [in their 2018 HSTT proposed rule comment letter] were not 
adequately addressed in the 2018-2023 Final Rule'' and asked that NMFS 
renew consideration of their prior comments. To the extent they raised 
concerns with how ``most'' issues were addressed previously, they did 
not identify which issues those were. The second letter from NGOs also 
attached their comments on the 2018 HSTT proposed rule and the Notice 
of Receipt of the 2017 Navy application.
    NMFS has reviewed and considered all public comments received on 
the 2019 HSTT proposed rule and issuance of the LOAs. In considering 
the comments received we realized that our responses to some of the 
comments on the 2018 HSTT proposed rule could benefit from additional 
detail and/or clarification. Accordingly, we are republishing the 
responses to comments received on the 2018 HSTT proposed rule, some of 
which have been updated, along with providing our responses to new 
comments on the 2019 proposed rule. Therefore, all relevant comments 
received on both the 2018 and 2019 HSTT proposed rules and our 
responses are presented below. We provide no response to specific 
comments that addressed species or statutes not relevant to our 
proposed authorization under section 101(a)(5)(A) of the MMPA (e.g., 
comments related to sea turtles) or species or stocks that do not occur 
in the HSTT Study Area (e.g., Southern Resident Killer whales).

General Comments

    The majority of the 18 comment letters received on the 2018 HSTT 
proposed rule and 27 comment letters received on the 2019 HSTT proposed 
rule from private citizens expressed general opposition toward the 
Navy's proposed training and testing activities and requested that NMFS 
not issue the LOAs while one comment on the 2019 HSTT proposed rule 
expressed general support, with none of these general commenters 
providing information relevant to NMFS' decisions. Therefore, these 
comments were not considered further. The remaining comments are 
addressed below.
    Comment 1: Some commenters expressed concern with issuing LOAs for 
seven years.
    Response: Under section 101(a)(5)(A) of the MMPA, applicants may 
apply for the incidental take coverage that they need for their 
activities and NMFS ``shall issue'' the requested authorizations 
provided certain findings (see the Background section) can be made. In 
August 2018, Congress amended the MMPA through the NDAA for Fiscal Year 
2019 to allow for seven-year authorizations for military readiness 
activities, as compared to the previously allowed five years. Following 
the statutory amendment, the Navy applied for longer term coverage for 
its testing and training activities in the HSTT Study Area, and with 
NMFS making the required findings through this rulemaking, issuance of 
regulations and LOAs for the longer period is appropriate.
    Comment 2: Several Commenters expressed concern and the need for 
increased reporting and assessment of impacts due to impacts of climate 
change on marine mammal populations.
    Response: We note that the Navy is required to provide annual 
reports to NMFS and the Adaptive Management process allows for timely 
modification of mitigation or monitoring measures based on new 
information, when appropriate (see the Mitigation Measures and 
Monitoring sections for additional detail). The reporting requirements 
included in this final rule are consistent with NMFS' regulations and 
the goals of the monitoring and reporting program, as discussed in the 
2018 HSTT final rule.

Impact Analysis

General
    Comment 3: In a comment on the 2018 HSTT proposed rule, a Commenter 
recommended that the Navy provide NMFS with an acoustics analysis that 
addresses noise impacts on land, from the air, and underwater. Full 
environmental analysis of the noise would examine a suite of metrics 
appropriate to the array of resources impacted. The impacts should 
discuss potential effects on wildlife, visitors, and other noise-
sensitive receivers.
    The commenter also recommended that the Navy consider the following 
as it plans to conduct activities in the HSTT Study Area:
     Use appropriate metrics to assess potential environmental 
impacts on land and water.
     Determine natural ambient acoustic conditions as a 
baseline for analysis.
     Assess effects from cumulative noise output, incorporating 
noise generated from other anthropogenic sources.
     Determine distance at which noise will attenuate to 
natural levels.
     Assess effects that these noise levels would have on 
terrestrial wildlife, marine wildlife, and visitors.
     Appropriate and effective mitigation measures should be 
developed and used to reduce vessel strike (e.g., timing activities to 
avoid migration, and searching for marine mammals before and during 
activities and taking avoidance measures).
    Response: The analysis conducted by the Navy and provided to NMFS 
was based on the best available science and provided NMFS with all 
information needed to conduct a complete and thorough analysis of the 
effects of Navy activities on affected marine mammals and their 
habitat. In addition, NMFS refers the Commenter to the 2018 HSTT FEIS/
OEIS which conducted an assessment of all of the activities which 
comprised the proposed action and their impacts (including cumulative 
impacts) along with alternatives to the proposed action and their 
impacts to relevant resources. In the context of this MMPA rule, the 
Navy was not required to do ambient noise monitoring or assess impacts 
to wildlife other than marine mammals or to visitors/tourists. The 
mitigation measures in this rule include procedural measures to use 
trained Lookouts to observe for marine mammals within a mitigation zone 
before, during, and after applicable activities to avoid or reduce 
potential impacts wherever and whenever training and testing activities 
occur. Additionally, the Navy will implement

[[Page 41794]]

measures within mitigation areas to avoid potential impacts in key 
areas of importance for marine mammal foraging, reproduction, and 
migration. The mitigation measures in this rule also include procedural 
measures to minimize vessel strike (avoiding whales by 500 yds, etc.), 
mitigation areas to minimize strike in biologically important areas, 
and Awareness Notification Message areas wherein all vessels are 
alerted to stay vigilant to the presence of large whales.
Density Estimates
    Comment 4: In a comment on the 2018 HSTT proposed rule, a Commenter 
stated that 30 iterations or Monte Carlo simulations is low for general 
bootstrapping methods used in those models but understands that 
increasing the number of iterations in turn increases the computational 
time needed to run the models. Accordingly, the Commenter suggested 
that the Navy consider increasing the iterations from 30 to at least 
200 for activities that have yet to be modeled for upcoming MMPA 
rulemakings for Navy testing and training activities.
    Response: In areas where there are four seasons, 30 iterations are 
used in NAEMO which results in a total of 120 iterations per year for 
each event. However, in areas where there are only two seasons, warm 
and cold, the number of iterations per season is increased to 60 so 
that 120 iterations per year are maintained. The Navy reached this 
number of iterations by running two iterations of a scenario and 
calculating the mean of exposures, then running a third iteration and 
calculating the running mean of exposures, then a fourth iteration and 
so on. This is done until the running mean becomes stable. Through this 
approach, it was determined 120 iterations was sufficient to converge 
to a statistically valid answer and provides a reasonable uniformity of 
exposure predictions for most species and areas. There are a few 
exceptions for species with sparsely populated distributions or highly 
variable distributions. In these cases, the running mean may not 
flatten out (or become stable); however, there were so few exposures in 
these cases that while the mean may fluctuate, the overall number of 
exposures did not result in significant differences in the totals. In 
total, the number of simulations conducted for HSTT Phase III exceeded 
six million simulations and produced hundreds of terabytes of data. 
Increasing the number of iterations, based on the discussion above, 
would not result in a significant change in the results, but would 
incur a significant increase in resources (e.g., computational and 
storage requirements). This would divert these resources from 
conducting other more consequential analysis without providing for 
meaningfully improved data. The Navy has communicated that it is 
continually looking at ways to improve NAEMO and reduce data and 
computational requirements. As technologies and computational 
efficiencies improve, the Navy will evaluate these advances and 
incorporate them where appropriate. NMFS has reviewed the Navy's 
approach and concurs that it is technically sound and reflects the best 
available science.
    Comment 5: In a comment on the 2018 HSTT proposed rule, a Commenter 
had concerns regarding the Navy's pinniped density estimates. Given 
that a single density was provided for the respective areas and 
pinnipeds were assumed to occur at sea as individual animals, 
uncertainty does not appear to have been incorporated in the Navy's 
animat modeling for pinnipeds. The Navy primarily used sightings or 
abundance data, assuming certain correction factors, divided by an area 
to estimate pinniped densities. Many, if not all, of the abundance 
estimates had associated measures of uncertainty (i.e., coefficients of 
variation (CV), standard deviation (SD), or standard error (SE)). 
Therefore, the Commenter recommended that NMFS require the Navy to 
specify whether and how it incorporated uncertainty in the pinniped 
density estimates into its animat modeling and if it did not, require 
the Navy to use measures of uncertainty inherent in the abundance data 
(i.e., CV, SD, SE) similar to the methods used for cetaceans.
    Response: As noted in the cited technical report ``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 did not apply statistical 
uncertainty outside the survey boundaries into non-surveyed areas, 
since it deemed application of statistical uncertainty would not be 
meaningful or appropriate. We note that there are no measures of 
uncertainty (i.e., no CV, SD, or SE) provided in NMFS Pacific Stock 
Assessment Report (SAR) Appendix 3 (Carretta et al., 2019) associated 
with the abundance data for any of the pinniped species present in 
Southern California. Although some measures of uncertainty are 
presented in some citations within the SAR and in other relevant 
publications for some survey findings, it is not appropriate for the 
Navy to attempt to derive summations of total uncertainty for an 
abundance when the authors of the cited studies and the SAR have not. 
For additional information regarding use of pinniped density data, see 
the cited ``U.S. Navy Marine Species Density Database Phase III for the 
Hawaii-Southern California Training and Testing Study Area'' Section 11 
(U.S. Department of the Navy, 2017b). As a result of the lack of 
published applicable measures of uncertainty for pinnipeds during this 
analysis, the Navy did not incorporate measures of uncertainty into the 
pinniped density estimates. NMFS independently reviewed the methods and 
densities used by the Navy and concur that they are appropriate and 
reflect the best available science.
    Comment 6: In a comment on the 2018 HSTT proposed rule, a Commenter 
had concerns regarding the various areas, abundance estimates, and 
correction factors that the Navy used for pinnipeds. The Commenter 
referenced a lot of information in the context of both what the Navy 
used and what the Commenter argued they could have used instead and 
summarized the discussion with several recommendations.
    For harbor seals, the area was based on the NMFS SOCAL stratum 
(extending to the extent of the U.S. exclusive economic zone (EEZ), 370 
km from the coast) for its vessel-based surveys (i.e., Barlow 2010) and 
the Navy applied the density estimates from the coast to 80 km 
offshore. The Commenter believes that this approach is inappropriate 
and that the Navy should use the area of occurrence to estimate the 
densities for harbor seals. For harbor seals, the Navy assumed that 22 
percent of the stock occurred in SOCAL, citing Department of the Navy 
(2015). The Commenter had two concerns with this approach. First, one 
has to go to Department of the Navy (2015) to determine the original 
source of the information (Lowry et al., 2008; see the commenter's 
February 20, 2014, letter on this matter). Second, Lowry et al. (2008) 
indicated that 23.3 percent of the harbor seal population occurred in 
SOCAL, not 22 percent as used by the Navy. Therefore, the Commenter 
recommended that, at the very least, NMFS require the Navy to revise 
the pinniped density estimates using the extent of the coastal range 
(e.g., from shore to 80 km offshore) of harbor seals as the applicable 
area, 23.3 percent of the California abundance estimate based on Lowry 
et al. (2008), and an at-sea correction factor of 65 percent based on 
Harvey and Goley (2011) for both seasons.

[[Page 41795]]

    For monk seals the area was based on the areas within the 200-m 
isobaths in both the Main and Northwest Hawaiian Islands (MHI and NWHI, 
respectively) and areas beyond the 200-m isobaths in the U.S. EEZ. The 
Commenter asserted that some of the abundances used were not based on 
best available science. The Navy noted that its monk seal abundance was 
less than that reported by Baker et al. (2016), but that those more 
recent data were not available when the Navy's modeling process began. 
The Baker et al. (2016) data have been available for almost two years 
and should have been incorporated accordingly, particularly since the 
data would yield greater densities and the species is endangered. For 
monk seals, the Commenter recommended using the 2015 monk seal 
abundance estimate from Baker et al. (2016) and an at-sea correction 
factor of 63 percent for the MHI based on Baker et al. (2016) and 69 
percent for the NWHI based on Harting et al. (2017).
    For the northern fur seals, the area was based on the NMFS SOCAL 
stratum (extending to the extent of the U.S. EEZ, 370 km from the 
coast) for its vessel-based surveys (i.e., Barlow, 2010). For elephant 
seals, California sea lions, and Guadalupe fur seals, the area was 
based on the Navy SOCAL modeling area. The Commenter had concerns that 
these areas are not based on the biology or ecology of these species. 
The Commenter recommended using the same representative area for 
elephant seals, northern fur seals, Guadalupe fur seals, and California 
sea lions.
    The Commenter recommended using an increasing trend of 3.8 percent 
annually for the last 15 years for elephant seals as part of the 
California population and at least 31,000 as representative of the 
Mexico population based on Lowry et al. (2014). Additionally, the 
commenter recommended using an at-sea correction factor of 44 percent 
for the cold season and 48 percent for the warm season for California 
sea lions based on Lowry and Forney (2005).
    Finally, the Commenter recommended that NMFS require the Navy to 
(1) specify the assumptions made and the underlying data that were used 
for the at-sea correction factors for Guadalupe and northern fur seals 
and (2) consult with experts in academia and at the NMFS Science 
Centers to develop more refined pinniped density estimates that account 
for pinniped movements, distribution, at-sea correction factors, and 
density gradients associated with proximity to haul-out sites or 
rookeries.
    Response: The Navy provided additional clarification regarding the 
referenced concerns about areas, abundance estimates, and correction 
factors that were used for pinnipeds. We note that take estimation is 
not an exact science. There are many inputs that go into an estimate of 
marine mammal exposure, and the data upon which those inputs are based 
come with varying levels of uncertainty and precision. Also, 
differences in life histories, behaviors, and distributions of stocks 
can support different decisions regarding methods in different 
situations. Different methods may be supportable in different 
situations, and, further, there may be more than one acceptable method 
to estimate take in a particular situation. Accordingly, while NMFS 
always ensures that the methods are technically supportable and reflect 
the best available science, NMFS does not prescribe any one method for 
estimating take (or calculating some of the specific take estimate 
components that the Commenter is concerned about). NMFS reviewed the 
areas, abundances, and correction factors used by the Navy to estimate 
take and concurs that they are appropriate. We note the following in 
further support of the analysis: while some of the suggestions the 
Commenter makes could provide alternate valid ways to conduct the 
analyses, these modifications are not required in order to have equally 
valid and supportable analyses and, further, would not change NMFS' 
determinations for pinnipeds. In addition, we note that (1) many of the 
specific recommendations that the Commenter makes are largely minor in 
nature: ``44 not 47 percent,'' ``63 not 61 percent,'' ``23.3 not 22 
percent'' or ``area being approximately 13 percent larger;'' and (2) 
even where the recommendation is somewhat larger in scale, given the 
ranges of these stocks, the size of the stocks, and the number and 
nature of pinniped takes, recalculating the estimated take for any of 
these pinniped stocks using the Commenter's recommended changes would 
not change NMFS' assessment of impacts on the recruitment or survival 
of any of these stocks, or the negligible impact determination. Below, 
we address the Commenter's issues in more detail and, while we do not 
explicitly note it in every section, NMFS has reviewed the Navy's 
analysis and choices in relation to these comments and concurs that 
they are technically sound and reflect the best available science.
    For harbor seals--Based on the results from satellite tracking of 
harbor seals at Monterey, California and the documented dive depths 
(Eguchi and Harvey, 2005), the extent of the range for harbor seals in 
the HSTT Study Area used by the Navy (a 50 Nmi buffer around all known 
haul-out sites; approximately 93 km) is more appropriate than the 
suggested 80 km offshore suggested by Commenter.
    The comment is incorrect in its claim that the NMFS and Navy did 
not use the best available science. Regarding the appropriate 
percentage of the California Current Ecosystem abundance to assign to 
the HSTT Study Area, the 22 percent that the Navy used is based on the 
most recent of the two years provided in Lowry et al. (2008) rather 
than the mean of two years, which is one valid approach. Additionally, 
since approximately 74 percent of the harbor seal population in the 
Channel Islands (Lowry et al., 2017) is present outside and to the 
north of the HSTT Study Area, it is a reasonable assumption that the 22 
percent used already provides a conservative overestimate and that it 
would not be appropriate to apply a higher percentage of the overall 
population for distribution into the Navy's modeling areas.
    Again, the comment is incorrect in its claim that the correction 
factors applied to population estimates were either unsubstantiated or 
incorrect. Regarding the Commenter's recommended use of an at-sea 
correction factor of 65 percent for both seasons based on Harvey and 
Goley (2011), that correction factor was specifically meant to apply to 
the single molting season when harbor seals are traditionally surveyed 
(see discussion in Lowry et al., 2017). Additionally, the authors of 
that study provided a correction factor (CF = 2.86; 35 percent) for 
Southern California but left open the appropriateness of that factor 
given the limited data available at the time. For these reasons, having 
separate correction factors for each of the seasons is more appropriate 
as detailed in Section 11.1.5 (Phoca vitulina, Pacific harbor seal) of 
the ``U.S. Navy Marine Species Density Database Phase III for the 
Hawaii-Southern California Training and Testing Study Area'' (U.S. 
Department of the Navy, 2017b).
    For monk seals, as detailed in Section 11.1.4 (Neomonachus 
schauinslandi, Hawaiian monk seal) of the ``U.S. Navy Marine Species 
Density Database Phase III for the Hawaii-Southern California Training 
and Testing Study Area'' (U.S. Department of the Navy, 2017b), the Navy 
consulted with the researchers and subject matter experts at the 
Pacific Science Center and the Monk Seal Recovery Team regarding the 
abundance estimates, at sea correction factors, and distribution for 
monk seals in the Hawaiian Islands during development

[[Page 41796]]

of the 2018 HSTT FEIS/OEIS throughout 2015 and the Summer of 2016, and 
as used subsequently in its MMPA application. The Navy incorporated the 
results of those consultations, including unpublished data, into the 
analysis of monk seals. Additional details in this regard to monk seal 
distributions and population trends as reflected by the abundance in 
the Hawaiian Islands are presented in the 2018 HSTT FEIS/OEIS in 
Section 3.7.2.2.9.2 (Habitat and Geographic Range) and Section 
3.7.2.2.9.3 (Population Trends). The Navy has indicated that it has 
continued ongoing communications with researchers at the Pacific 
Islands Science Center and elsewhere, has accounted for the findings in 
the citations noted by the Commenter (Baker et al., 2016; Harting et 
al., 2017) as well as information in forthcoming publications provided 
ahead of publication via those researchers (cited as in preparation), 
and specifically asked for and received concurrence from subject matter 
experts regarding specific findings presented in the 2018 HSTT FEIS/
OEIS regarding monk seals. The Navy also considered (subsequent to 
publication of the 2018 HSTT FEIS/OEIS) the new Main Hawaiian Islands 
haul-out correction factor presented in the publication by Wilson et 
al. (2017, which would be inconsistent with the use of the Baker et al. 
(2016) correction factors suggested by the Commenter), and the Harting 
et al. (2017) correction factor, and considered the new abundance 
numbers presented in the 2016 Stock Assessment Report, which first 
became available in January 2018. It is the Navy's assessment that a 
revision of the monk seal at-sea density would only result in small 
changes to the predicted effects and certainly would not change the 
conclusions presented in the 2018 HSTT FEIS/OEIS regarding impact on 
the population or the impact on the species. NMFS concurs with this 
conclusion. The Navy has communicated that it assumes that as part of 
the ongoing regulatory discussions with NMFS, changes to estimates of 
effects can be best dealt with in the next rulemaking given Wilson et 
al. (2017) has now also provided a totally new haulout correction 
factor for the Main Hawaiian Islands that was not considered in Baker 
et al. (2016), Harting et al. (2017), or the 2016 SAR. NMFS agrees.
    For northern fur seals, elephant seals, California sea lions, and 
Guadalupe fur seals, the Navy consulted with various subject matter 
experts regarding the abundances and distributions used in the 2018 
HSTT FEIS/OEIS analyses for these species and based on those 
consultations and the literature available, the Navy and NMFS believe 
that the findings presented in the 2018 HSTT FEIS/OEIS and supporting 
technical reports provide the most accurate assessments available for 
these species. Given the demonstrated differences in the at-sea 
distributions of elephant seals, northern fur seals, Guadalupe fur 
seals, and California sea lions (Gearin et al., 2017; Lowry et al., 
2014; Lowry, et al., 2017; Norris, 2017; Norris, et al., 2015; Robinson 
et al., 2012; University of California Santa Cruz and National Marine 
Fisheries Service, 2016), it would not be appropriate to use the same 
representative area for distributions of these species' population 
abundances. For example, California sea lions forage predominantly 
within 20 nmi from shore (Lowry and Forney, 2005), while tag data shows 
that many elephant seals (Robinson et al., 2012) and Guadalupe fur 
seals (Norris, 2017) seasonally forage in deep waters of the Pacific 
well outside the boundaries of the HSTT Study Area.
    For northern elephant seals (Mirounga angustirostris, Northern 
elephant seal), as detailed in Section 11.1.3 of the technical report 
titled U.S. Navy Marine Species Density Database Phase III for the 
Hawaii-Southern California Training and Testing Study Area (U.S. 
Department of the Navy, 2017b), the Navy considered a number of factors 
in the development of the data for this species, including the fact 
that not all of the elephant seal population is likely to occur 
exclusively within the Southern California portion of the HSTT Study 
Area. Given that the three main rookeries considered in this analysis 
are located at the northern boundary of the HSTT Study Area and that 
elephant seals migrate northward after the breeding season, the Navy, 
in consultation with subject matter experts, believes the current 
abundance used in the analysis is based on the best available science 
and represents a conservative overestimate of the number of elephant 
seals likely to be affected by Navy activities in the HSTT Study Area. 
NMFS agrees with this assessment, and it was used in the MMPA analysis.
    For California sea lions, the citation (Lowry and Forney, 2005) 
used as the basis for this recommendation specifically addressed the 
use of the Central and Northern California at-sea correction factor 
elsewhere, with the authors stating; ``In particular, [use of the 
Central and Northern California at-sea correction factor] would not be 
appropriate for regions where sea lions reproduce, such as in the 
Southern California Bight (SCB) and in Mexico, . . .'' Given the waters 
of the Southern California Bight and off Mexico overlap the HSTT Study 
Area and since the authors of the cited study specifically recommended 
not using the correction factor in the manner the Commenter suggested, 
the Navy does not believe use of that correction factor for the HSTT 
Study Area would be appropriate. NMFS concurs with this approach.
    For Guadalupe fur seal--Additional detail regarding the data used 
for the analysis of Guadalupe fur seals was added to the 2018 HSTT 
FEIS/OEIS Section 3.7.2.2.8 (Arctocephalus townsendi, Guadalupe Fur 
Seal). The Navy had integrated the latest (September 2017) unpublished 
data for Guadalupe fur seals from researchers in the United States and 
Mexico into the at-sea correction factor and density distribution of 
the species used in the modeling, but consultations with experts in 
academia and at the NMFS Science Centers and their recommendations had 
not been finalized before release of the Draft EIS/OEIS. Subsequently, 
this revision of the text was not considered critical for the final 
NEPA document since the new data did not provide any significant change 
to the conclusions reached regarding the Guadalupe fur seal population. 
In fact, the data indicates an increase in the population and expansion 
of their range concurrent with decades of ongoing Navy training and 
testing in the SOCAL range complex. The Navy recently supported new 
census and at-sea satellite tagging of Guadalupe fur seals in 2018 and 
2019. These data were not available during the development of the 2018 
HSTT FEIS/OEIS, but the results do not change the overall conclusions. 
For instance, Guadalupe fur seals tagged to date are truly pelagic and 
mainly transit the offshore (<2000 m) waters of the HSTT SOCAL area 
(Norris et al., 2019a, 2019b; Norris et al., 2020). Therefore, modeled 
takes are likely an over-prediction of exposure. NMFS agrees with this 
assessment, and it was used in the MMPA analysis.
    For Northern Fur Seal--As presented in Section 11.1.2 (Callorhinus 
ursinus, Northern fur seal) of the Navy's Density Technical Report 
(U.S. Department of the Navy, 2017b), the correction factor percentages 
for northern fur seals potentially at sea were derived from the 
published literature as cited (Antonelis et al., 1990; Ream, et al., 
2005; Roppel, 1984).
    For future EISs, the Navy explained that it did and will continue 
to consult with authors of the papers relevant to the analyses as well 
as other experts in

[[Page 41797]]

academia and at the NMFS Science Centers during the development of the 
Navy's analyses. During the development of the 2018 HSTT EIS/OEIS and 
as late as September 2017, the Navy had ongoing communications with 
various subject matter experts and specifically discussed pinniped 
movements, the distribution of populations within the study area to 
support the analyses, the pinniped haulout or at-sea correction 
factors, and the appropriateness of density gradients associated with 
proximity to haul-out sites or rookeries. As shown in the references 
cited, the personal communications with researchers have been made part 
of the public record, although many other informal discussions with 
colleagues have also assisted in the Navy's approach to the analyses 
presented.
    The Navy acknowledges that there have been previous comments 
provided by this Commenter on other Navy range complex documents 
regarding the use of satellite tag movement and location data to derive 
at-sea pinniped density data, and the Navy asserts that previous 
responses to those comments remain valid. Additionally, the Commenter 
has noted that the ``. . . Commenter continues to believe that data 
regarding movements and dispersion of tagged pinnipeds could yield 
better approximations of densities than the methods the Navy currently 
uses.'' The Navy acknowledges that in comments to previous HSTT EIS/
OEIS analyses, the Commenter has recommended this untried approach; 
responses to those previous comments have been provided. The Navy also 
notes that there have been papers suggesting the future application of 
Bayesian or Markov chain techniques for use in habitat modeling (e.g., 
Redfern et al., 2006) and overcoming the bias introduced by 
interpretation of population habitat use based on non-randomized 
tagging locations (e.g., Whitehead and Jonsen, 2013). However, the use 
of satellite tag location data in a Bayesian approach to derive 
cetacean or pinniped densities at sea has yet to be accepted, 
implemented, or even introduced in the scientific literature.
    This issue was in fact recently discussed as part of the Density 
Modeling Workshop associated with the October 2017 Society for Marine 
Mammalogy conference. The consensus of the marine mammal scientists 
present was that while pinniped tag data could provide a good test 
case, it realistically was unlikely to be a focus of the near-term 
research. The working group determined that a focused technical group 
should be established to specifically discuss pinnipeds and data 
available for density surface modelling in the future. It was also 
discussed at the Density Modeling Workshop in October 2018. The Navy 
has convened a pinniped working group and NMFS Alaska Fisheries Science 
Center is sponsoring a demonstration project to use haul-out and 
telemetry data from seals in Alaska to determine the viability of such 
an approach.
    Therefore, consistent with previous assessments and based on recent 
discussions with subject matter experts in academia, the NMFS Science 
Centers, and the National Marine Mammal Laboratory, and given there is 
no currently established methodology for implementing the approach 
suggested by the Commenter, the Navy believes that attempting to create 
and apply a new density derivation method at this point would introduce 
additional levels of uncertainty into density estimations.
    For these reasons, the Navy and NMFS did not use density estimates 
based on pinniped tracking data. Publications reporting on satellite 
tag location data have been and will continue to be used to aid in the 
understanding of pinniped distributions and density calculations as 
referenced in the 2018 HSTT FEIS/OEIS and the Navy's ``U.S. Navy Marine 
Species Density Database Phase III for the Hawaii-Southern California 
Training and Testing Study Area'' report (U.S. Department of the Navy, 
2017b). The Navy has communicated that it will continue, as it has in 
the past, to refine pinniped density and distributions using telemetry 
data and evolving new techniques (such as passive acoustic survey data) 
in development of the Navy's analyses. As noted above, NMFS has 
reviewed the Navy's methods and concurs that they are appropriate and 
reflect the best available science.
    Comment 7: Commenters noted that in the 2018 HSTT final rule, NMFS 
stated that it would incorporate the best and most recently available 
abundance and haul out data for monk seals into its next rulemaking, 
but failed to do so in the 2019 HSTT proposed rule. They argued that in 
light of the critical status of the monk seals, which number 
approximately 1,415 individuals, there is no justification for NMFS' 
failure to comply with the MMPA's command to incorporate the best 
available science into the proposed extension rule.
    Response: As described in the response to Comment 6, in developing 
the Marine Species Density Database Phase III for the Hawaii-Southern 
California Training and Testing Study Area, as part of the 2018 HSTT 
FEIS/OEIS, the Navy consulted with researchers and subject matter 
experts at NMFS' Pacific Islands Fisheries Science Center and the Monk 
Seal Recovery Team regarding the abundance estimates, at sea correction 
factors, and distribution for monk seals in the Hawaiian Islands. The 
Navy incorporated the results of those consultations, including 
unpublished data from Wilson et al., then in review, into the analysis 
of monk seals for the 2018 HSTT FEIS/OEIS and the 2017 and 2019 Navy 
Applications. When developing the analysis for monk seals, the Navy, in 
consultation with researchers at the NMFS Pacific Islands Fisheries 
Science Center, incorporated an estimated increased monk seal 
abundance. The published SAR for Hawaiian monk seals at the time (2015) 
reported a population size of 1,112, however in consultation with NMFS 
the Navy used a population size of 1,300. This estimate was also in 
agreement with the population size estimates reported by Baker et al. 
(2016) (2013 = 1,291, 2014 = 1,309, 2015 = 1,324). The most recent 
draft 2019 SARs report a population size of 1,351 and the abundance 
estimate used in the Navy's analyses is within the 95 percent 
confidence interval (1,294-1,442; CV = 0.03). It is the Navy's 
assessment that a revision of the monk seal at-sea density (given the 
most recent abundance estimate of 1,351) would result in only very 
small changes to the predicted effects (particularly given the 
distribution of monk seals in the HSTT Study Area) and would not change 
the conclusions presented in the 2018 HSTT FEIS/OEIS and 2017 and 2019 
Navy applications regarding impact on the population or the impact on 
the species. NMFS concurs with this conclusion. NMFS and the Navy will 
continue to consider the most recent and best available data in future 
EIS and MMPA rule analyses.
    Comment 8: In a comment on the 2018 HSTT proposed rule, a Commenter 
recommended that NMFS require the Navy to (1) specify what modeling 
method and underlying assumptions, including any relevant source 
spectra and assumed animal swim speeds and turnover rates, were used to 
estimate the ranges to PTS and TTS for impact and vibratory pile-
driving activities, (2) accumulate the energy for the entire day of 
proposed activities to determine the ranges to PTS and TTS for impact 
and vibratory pile-driving activities, and (3) clarify why the PTS and 
TTS ranges were estimated to be the same for LF and HF cetaceans during 
impact pile driving.
    Response: As explained in Section 3.7.3.1.4.1 of the 2018 HSTT 
FEIS/OEIS,

[[Page 41798]]

the Navy measured values for source levels and transmission loss from 
pile driving of the Elevated Causeway System, the only pile driving 
activity included in the Specified Activity. The Navy reviewed the 
source levels and how the spectrum was used to calculate the range to 
effects; NMFS supports the use of these measured values for the MMPA 
analysis. These recorded source waveforms were weighted using the 
auditory weighting functions. Low-frequency and high-frequency 
cetaceans have similar ranges for impact pile driving since low-
frequency cetaceans would be relatively more sensitive to the low-
frequency sound which is below high-frequency cetaceans' best range of 
hearing. Neither the NMFS user spreadsheet nor NAEMO were required for 
calculations. An area density model was developed in MS Excel which 
calculated zones of influence (ZOI) to thresholds of interest (e.g., 
behavioral response) based on durations of pile driving and the 
aforementioned measured and weighted source level values. The resulting 
area was then multiplied by density of each marine mammal species that 
could occur within the vicinity. This produced an estimated number of 
animals that could be impacted per pile, per day, and overall during 
the entire activity for both the impact pile driving and vibratory 
removal phases. NMFS reviewed the manner in which the Navy applied the 
frequency weighting and calculated all values and concurred with the 
approach.
    Regarding the appropriateness of accumulating energy for the entire 
day, based on the best available science regarding animal reaction to 
sound, selecting a reasonable SEL calculation period is necessary to 
more accurately reflect the time period an animal would likely be 
exposed to the sound. The Navy factored both mitigation effectiveness 
and animal avoidance of higher sound levels into the impact pile 
driving analysis. For impact pile driving, the mitigation zone extends 
beyond the average ranges to PTS for all hearing groups; therefore, 
mitigation will help prevent or reduce the potential for exposure to 
PTS. The impact pile driving mitigation zone also extends beyond or 
into a portion of the average ranges to TTS; therefore, mitigation will 
help prevent or reduce the potential for exposure to all TTS or some 
higher levels of TTS, depending on the hearing group. Mitigation 
effectiveness and animal avoidance of higher sound levels were both 
factored into the impact pile driving analysis as most marine mammals 
should be able to easily move away from the expanding ensonified zone 
of TTS/PTS within 60 seconds, especially considering the soft start 
procedure, or avoid the zone altogether if they are outside of the 
immediate area upon startup. Marine mammals are likely to leave the 
immediate area of pile driving and extraction activities and be less 
likely to return as activities persist. However, some ``naive'' animals 
may enter the area during the short period of time when pile driving 
and extraction equipment is being re-positioned between piles. 
Therefore, an animal ``refresh rate'' of 10 percent was selected. This 
means that 10 percent of the single pile ZOI was added for each 
consecutive pile within a given 24-hour period to generate the daily 
ZOI per effect category. These daily ZOIs were then multiplied by the 
number of days of pile driving and pile extraction and then summed to 
generate a total ZOI per effect category (i.e., behavioral response, 
TTS, PTS). The small size of the mitigation zone and its close 
proximity to the observation platform will result in a high likelihood 
that Lookouts would be able to detect marine mammals throughout the 
mitigation zone. NMFS concurs with the Navy's approach, and it was used 
in the MMPA analysis.
PTS/TTS Thresholds
    Comment 9: In a comment on the 2018 HSTT proposed rule, a Commenter 
supported the weighting functions and associated thresholds as 
stipulated in Finneran (2016), which are the same as those used for 
Navy Phase III activities, but points to additional recent studies that 
provide additional behavioral audiograms (e.g., Branstetter et al., 
2017; Kastelein et al., 2017b) and information on TTS (e.g., Kastelein 
et al., 2017a, 2017c). However, they commented that the Navy should 
provide a discussion of whether those new data corroborate the current 
weighting functions and associated thresholds.
    Response: The 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 2016 Acoustic Technical Guidance. 
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. Thus far, no new information has been published or 
otherwise conveyed that would fundamentally change the assessment of 
impacts or conclusions of this rule. 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.
    Comment 10: In a comment on the 2018 HSTT proposed rule, Commenters 
stated that the criteria that NMFS has produced to estimate temporary 
threshold shift (TTS) and permanent threshold shift (PTS) in marine 
mammals are erroneous and non-conservative. Commenters cited multiple 
purported issues with NMFS' Acoustic Technical Guidance, such as 
pseudoreplication and inconsistent treatment of data, broad 
extrapolation from a small number of individuals, and disregarding 
``non-linear accumulation of uncertainty.'' Commenters suggested that 
NMFS not rely exclusively on its auditory guidance for determining 
Level A harassment take, but should at a minimum retain the historical 
180-dB rms Level A harassment threshold as a ``conservative upper 
bound'' or conduct a ``sensitivity analysis'' to ``understand the 
potential magnitude'' of the supposed errors.
    Response: NMFS disagrees with this characterization of the Acoustic 
Technical Guidance and the associated recommendation. The Acoustic 
Technical Guidance is a compilation, interpretation, and synthesis of 
the scientific literature that provides the best scientific information 
regarding the effects of anthropogenic sound on marine mammals' 
hearing. The technical guidance was classified as a Highly Influential 
Scientific Assessment and, as such, underwent three independent peer 
reviews, at three different stages in its development, including a 
follow-up to one of the peer reviews, prior to its dissemination by 
NMFS. In addition, there were three separate public comment periods, 
during which time we received and responded to similar comments on the 
guidance (81 FR 51694), which we cross-reference here, and more recent 
public and interagency review under Executive Order 13795. This review 
process was scientifically rigorous and

[[Page 41799]]

ensured that the Guidance represents the best scientific data 
available. 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.
    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.
    Multiple studies from humans, terrestrial mammals, and marine 
mammals have demonstrated less 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 
behavioral 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 dolphins. Their TTS 
(unweighted) onset values 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.
Behavioral Harassment Thresholds
    Comment 11: In a comment on the 2018 HSTT proposed rule, Commenters 
commented on what they assert is NMFS' failure to set proper thresholds 
for behavioral impacts. Referencing the biphasic function that assumes 
an unmediated dose response relationship at higher received levels and 
a context-influenced response at lower received levels that NMFS uses 
to quantify behavioral harassment from sonar, Commenters commented that 
resulting functions depend on some inappropriate assumptions that tend 
to significantly underestimate effects. Commenters expressed concern 
that every data point that informs the agency's pinniped function, and 
nearly two-thirds of the data points informing the odontocete function 
(30/49), are derived from a captive animal study. Additionally, 
Commenters asserted that the risk functions do not incorporate (nor 
does NMFS apparently consider) a number of relevant studies on wild 
marine mammals. The Commenters stated that 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 in the rule 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 concerns that the 
functions are not conservative for some species. Commenters recommended 
NMFS make additional technical information available, including from 
any expert elicitation and peer review, so that the public can fully 
comment.
    Response: 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, 2017a) details how the Navy's proposed 
method, which was determined appropriate and adopted by NMFS, accounted 
for the differences in captive and wild animals in the development of 
the behavioral response functions. The Navy used the best available 
science, which has been reviewed by external scientists and approved by 
NMFS, in the analysis. The Navy and NMFS have utilized all available 
data that relate known or estimable received levels to observations of 
individual or group behavior as a result of sonar exposure (which is 
needed to inform the behavioral response function) for the development 
of updated thresholds. Limiting the data to the small number of field 
studies that include these necessary data would not provide enough data 
with which to develop the new risk functions. In addition, NMFS agrees 
with the assumptions made by the Navy, including the fact that captive 
animals may be less sensitive, in that 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 agency 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. As new science 
is published, NMFS and the Navy continue to evaluate the information. 
The

[[Page 41800]]

thresholds have been rigorously vetted among scientists and within the 
Navy community and then reviewed by the public before being applied--
all applicable technical information considered has been shared with 
the public. It is not possible to revise and update the criteria and 
risk functions every time a new paper is published. These new papers 
provide additional information, and the Navy has considered them for 
updates to the thresholds 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 HSTT FEIS/OEIS or this 
rule. To be included in the behavioral response function, data sets 
need 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.
    As noted, the derivation of the behavioral response functions is 
provided in the 2017 technical report titled ``Criteria and Thresholds 
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)''. 
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.
    Comment 12: In a comment on the 2018 HSTT proposed rule, Commenters 
stated concerns with the use of distance ``cut-offs'' in the behavioral 
harassment thresholds, and one commenter recommended that NMFS refrain 
from using cut-off distances in conjunction with the Bayesian BRFs and 
re-estimate the numbers of marine mammal takes based solely on the 
Bayesian BRFs.
    Response: The consideration of proximity (cut-off distances) was 
part of the criteria developed in consultation between the Navy and 
NMFS, is appropriate based on the best available science which shows 
that marine mammal responses to sound vary based on both sound level 
and distance, and was 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 
is 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 under military readiness for the 
actions analyzed within the 2018 HSTT FEIS/OEIS and included in these 
regulations. NMFS has independently assessed the Navy's behavioral 
harassment thresholds and believes that they appropriately apply the 
best available science and it is not necessary to recalculate take 
estimates.
    The Commenter 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 Commenter finds 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 a behavioral 
harassment 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 13: In a comment on the 2018 HSTT proposed rule regarding 
cut-off distances, Commenters noted that dipping sonar appears to be a 
significant predictor of deep-dive rates in beaked whales on Southern 
California Anti-submarine Warfare Range (SOAR), 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. Importantly, these effects were observed at 
substantially greater distances (e.g., 30 or more km) from dipping 
sonar than would otherwise be expected given the systems' source levels 
and the beaked whale response thresholds developed from research on 
hull-mounted sonar. Commenters suggested that the analysis, and 
associated cut-off distances, do not properly consider the impacts of 
dipping sonar.
    Response: The Navy relied upon the best science that was available 
to develop the behavioral response functions in consultation with NMFS. 
The Navy's 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.
    The referenced article (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 other 
new information that has been published or otherwise conveyed since the 
2018 HSTT proposed rule was published would change the assessment of 
impacts or conclusions in the 2018 HSTT FEIS/OEIS or in this 
rulemaking. Nonetheless, the new information and data presented in the 
new 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 whale documented high site fidelity to this area (Schorr et al., 
2018, updated in 2020).
    Comment 14: In a comment on the 2018 HSTT proposed rule regarding 
the behavioral thresholds for explosives, Commenters recommended that 
NMFS

[[Page 41801]]

estimate and ultimately authorize behavioral takes of marine mammals 
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 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 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 harassed and those potential impacts are considered in 
the negligible impact determination.
    All of the Navy's monitoring projects, reports, and publications 
are available on the marine species monitoring web page (https://www.navymarinespeciesmonitoring. us/). NMFS will continue to review 
applicable monitoring and science data and consider modifying these 
criteria when and if new information suggests it is appropriate.
Mortality and injury thresholds for explosions
    Comment 15: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that NMFS require the Navy to (1) explain why the 
constants and exponents for onset mortality and onset slight lung 
injury thresholds for Phase III have been amended, (2) ensure that the 
modified equations are correct, and (3) specify any additional 
assumptions that were made.
    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)''. It is our understanding that the 
constants and exponents for onset mortality and onset slight lung 
injury were amended by the Navy since Phase II to better account for 
the best available science. 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.
    Comment 16: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that the Navy only used the onset mortality and onset 
slight lung injury criteria to determine the range to effects, while it 
used the 50 percent mortality and 50 percent slight lung injury 
criteria to estimate the numbers of marine mammal takes. The Commenter 
believes that this approach is inconsistent with the manner in which 
the Navy estimated the numbers of takes for PTS, TTS, and behavioral 
disruption for explosive activities. All of those takes have been and 
continue to be based on onset, not 50-percent values. The Commenter 
commented on circumstances of the deaths of multiple common dolphins 
during one of the Navy's underwater detonation events in March 2011 
(Danil and St. Leger, 2011) and indicated that the Navy's mitigation 
measures are not fully effective, especially for explosive activities. 
The Commenter believes it would be more prudent for the Navy to 
estimate injuries and mortalities based on onset rather than a 50-
percent incidence of occurrence. The Navy did indicate that it is 
reasonable to assume for its impact analysis--thus its take estimation 
process--that extensive lung hemorrhage is a level of injury that would 
result in mortality for a wild animal (Department of the Navy 2017a). 
Thus, the Commenter asserted that it is unclear why the Navy did not 
follow through with that premise. The Commenter recommended that NMFS 
use onset mortality, onset slight lung injury, and onset GI tract 
injury thresholds to estimate both the numbers of marine mammal takes 
and the respective ranges to effect.
    Response: Based on an extensive review of the incident referred to 
by the Commenter, in coordination with NMFS the Navy revised and 
updated the mitigation for these types of events. There have been no 
further incidents since these mitigation changes were instituted in 
2011. The Navy used the range to one percent risk of mortality and 
injury (referred to as ``onset'' in the Draft EIS/OEIS) to inform the 
development of mitigation zones for explosives. 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). The 2018 HSTT FEIS/OEIS clarified that the ``onset'' non-
auditory injury and mortality criteria are actually one percent risk 
criteria.
    Over-predicting impacts, which would occur with the use of one 
percent non-auditory injury risk criteria in the quantitative analysis, 
would not afford extra protection to any animal. 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. 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).''
Range to Effects
    Comment 17: In a comment on the 2018 HSTT proposed rule, a 
Commenter noted that regarding TTS, the ranges to effect provided in 
Table 25 of the Federal Register notice of the 2018 HSTT proposed rule 
and Table 6-4 of the 2017 Navy application appear to be incorrect. The 
ranges for LF cetaceans should increase with increasing sonar emission 
time. Therefore, the Commenter recommended that NMFS determine what the 
appropriate ranges to TTS for bin LF5 should be and amend

[[Page 41802]]

the ranges for the various functional hearing groups in the tables 
accordingly.
    Response: The table regarding the Range to Temporary Threshold 
Shift for sonar bin LF5 over a representative range of environments 
within the HSTT Study Area (Table 25 in the Proposed and Final Rules) 
is correct. The reason the values in the tables in the rules and the 
2018 HSTT FEIS/OEIS do not change over the indicated interval (1 sec, 
30 sec, 60 sec, 120 sec) is that the LF5 pulse interval is longer than 
these values, hence the same range to TTS in the table. The values are 
consistent across the board because the max source level of LF5 (<180 
dB SPL) is so close to the LF cetacean TTS threshold 179 dB SEL. At 
such small range to effects, the resolution of NAEMO comes into play, 
and such small changes in range to effects cannot be discerned between 
the example durations.
Mitigation and Avoidance Calculations
    Comment 18: In a comment on the 2018 HSTT proposed rule, Commenters 
cited concerns that there was not enough information by which to 
evaluate the Navy's post-modeling calculations to account for 
mitigation and avoidance and imply that Level A takes and mortality 
takes may be underestimated. One Commenter recommended that NMFS (1) 
authorize 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) use those numbers, in 
addition to the revised Level B harassment takes, to inform its 
negligible impact determination analyses.
    Response: The consideration of marine mammal avoidance and 
mitigation effectiveness is integral to 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 2018 
HSTT final rule.
    Sound levels diminish quickly below levels that could cause PTS. 
Studies have shown that all animals observed avoid areas well beyond 
these zones; therefore, the vast majority of animals are likely to 
avoid sound levels that could cause injury to their ear. As discussed 
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,'' animats in the Navy's 
acoustic effects model do not move horizontally or ``react'' to sound 
in any way. However, the current best available science based on a 
growing body of behavioral response research shows that 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 (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, 2017a)) and Southall et al. (2019a). Avoidance 
to this distance greatly reduces the likelihood of impacts to hearing 
such as TTS and PTS. 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).
    Specifically, behavioral response literature, including the recent 
3S and SOCAL BRS studies, indicate that the 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. 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.
    As discussed 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'' 
and the 2018 HSTT final rule, 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 Level 
A take 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. 
Lastly, 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'' very clearly explains in 
detail how species sightability, the Lookout's ability to observe the 
range to PTS (for sonar and other transducers) and mortality (for 
explosives), 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 the ability for 
sound sources to be positively controlled (powered down) are considered 
in the post-modeling calculation to account for mitigation and 
avoidance. It is not necessary to view the many tables of numbers 
generated in the assessment to evaluate the method.
    Comment 19: In a comment on the 2019 HSTT proposed rule, Commenters 
noted that the Navy and NMFS failed to consider the maximum amount of 
take that is likely to occur because the Navy's computer modeled take 
is reduced based on unsubstantiated assumptions concerning the 
effectiveness of the Navy's procedural mitigation measures (primarily 
Lookouts with some passive acoustic monitoring) and the rates at which 
mammals avoid permanent threshold shift (PTS) exposure levels. 
Therefore, they assert that the PTS and injury (Level A) take estimates 
are low, and the negligible impact analysis is invalid because the 
numbers considered by NMFS are arbitrary. They provide the following 
example to illustrate their point: 2013 model-estimated PTS for blue 
whales was 116 individual instances of take (see Navy Marine Mammal 
Program, Space and Naval Warfare Systems Center Pacific, Post-Model 
Quantitative Analysis of Animal Avoidance Behavior and Mitigation 
Effectiveness for Hawaii-Southern California Training and Testing, 39

[[Page 41803]]

(Table 5-1) (August 27, 2013)). After implementation of mitigation, the 
estimated instances of PTS were reduced to 9 instances, and after 
assumed rates of animal avoidance were added, the estimated instances 
of take were reduced to 0. The Commenters asserted that in other words, 
the Navy assumed that it would be able to reduce 92 percent of modeled 
PTS for blue whales based on the effectiveness of its Lookouts and that 
PTS take estimates for other cetaceans are reduced at similar rates. 
The Commenters noted that there is no apparent rational basis for the 
extremely high rates of effectiveness (over 90 percent) the Navy claims 
for its procedural mitigation. They asserted that it is difficult to 
assess these claims, as neither the Navy nor NMFS has disclosed the 
actual numbers used to assess mitigation effectiveness for cetaceans 
along the four factors (species sightability, observation area, 
visibility, positive control). The Commenters requested that NMFS 
disclose those numbers and justify its reliance on them. The Commenters 
also incorporated the critiques raised by the Marine Mammal Commission 
in its 2017 comment letter concerning: (i) The comparative 
ineffectiveness of marine observers compared to line-transect 
observers; and (ii) the assumed 95 percent animal avoidance rate for 
PTS. In particular, they assert that references cited by NMFS and the 
Navy do not support the conclusion that cetaceans (other than beaked 
whales) regularly avoid sonar sources so as to mitigate PTS.
    Response: As noted in response to a similar comment on the 2018 
HSTT proposed rule (see Comment 18 above), the consideration of marine 
mammal avoidance and mitigation effectiveness is integral to 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. The example presented by 
the Commenters is based on the analysis conducted during the 2013-2018 
rulemaking (Phase II), rather than the current Phase III analysis used 
for this rule, so it is not applicable to this final rule. See the 
response to Comment 20 below for more information on how avoidance and 
mitigation effectiveness are evaluated.
    Comment 20: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated in regard to the method in 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. An animal 
being beyond the PTS zone initially has no bearing on whether it will 
come within close range later during an exercise since both sources and 
animals are moving. In addition, Navy vessels may move faster than the 
ability of the animals to evacuate the area. The Navy should have been 
able to query the dosimeters of the animats to verify whether its 5-
percent assumption was valid. The Commenter expressed concerned that 
this method underestimates the number of PTS takes.
    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 this approach and 
concurs that it is 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. 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. The Commenter 
referenced comments that they have previously submitted on the Navy's 
Gulf of Alaska incidental take regulations and we refer the Commenter 
to NMFS' responses, which were included in the Federal Register 
document announcing the issuance of the final regulations (82 FR 19572, 
April 27, 2017).
Underestimated Beaked Whale Injury and Mortality
    Comment 21: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that the Navy and NMFS both underestimate take for 
Cuvier's beaked whales because they are extremely sensitive to sonar. A 
new study of Cuvier's beaked whales in Southern California exposed to 
mid and high-power sonar confirmed that they modify their diving 
behavior up to 100-km away (Falcone et al., 2017). The Commenter 
asserted that this science disproves NMFS' assumption that beaked 
whales will find suitable habitat nearby within their small range. This 
modified diving behavior, which was particularly strong when exposed to 
mid-power sonar, indicates disruption of feeding. Accordingly, impacts 
on Cuvier's beaked whales could include interference with essential 
behaviors that will have more than a negligible impact on this species. 
In addition, Lookouts and shutdowns do not protect Cuvier's beaked 
whales from Navy sonar because this is a deep-diving species that is 
difficult to see from ships.
    Response: Takes of Cuvier's beaked whales are not underestimated. 
The behavioral harassment threshold for beaked whales has two 
components, both of which consider the sensitivity of beaked whales. 
First, the biphasic behavioral harassment function for beaked whales, 
which is based on data on beaked whale responses, has a significantly 
lower mid-point than other groups and also reflects a significantly 
higher probability of ``take'' at lower levels (e.g., close to 15 
percent at 120 dB). Additionally, the distance cut-off used for beaked 
whales is farther than for any other group (50 km, for both the MF1 and 
MF4 bins, acknowledging the fact that the unpredictability of dipping 
sonar likely results in takes at greater

[[Page 41804]]

distances than other more predictable sources of similar levels). 
Regarding the referenced article, the Commenter has cited only part of 
it. The study, which compiles information from multiple studies, found 
that shallow dives were predicted to increase in duration as the 
distance to both high-and mid-power MFAS sources decreased, beginning 
at approximately 100 km away and, specifically, the differences only 
varied from approximately 20 minutes without MFAS to about 24 minutes 
with MFAS at the closest distance (i.e., the dive time varied from 20 
to 24 minutes over the distance of 100 km away to the closest distance 
measured). Further, the same article predicted that deep dive duration 
(which is more directly associated with feeding and linked to potential 
energetic effects) was predicted to increase with proximity to mid-
power MFAS from approximately 60 minutes to approximately 90 minutes 
beginning at around 40 km (10 dives). There were four deep dives 
exposed to high-power MFAS within 20 km, the distance at which deep 
dive durations increased with the lower power source types. Other 
responses to MFAS included deep dives that were shorter than typical 
and shallower, and instances where there were no observed responses at 
closer distances. The threshold for Level B harassment is higher than 
just ``any measurable response'' and NMFS and the Navy worked closely 
together to identify behavioral response functions and distance cut-
offs that reflect the best available science to identify when marine 
mammal behavioral patterns will be disrupted to a point where they are 
abandoned or significantly altered. Further, the take estimate is in no 
way based on an assumption that beaked whales will always be sighted by 
Lookouts--and adjustment to account for Lookout effectiveness considers 
the variable detectability of different species. In this rule, both the 
take estimate and the negligible impact analysis appropriately consider 
the sensitivity of, and scale of impacts to (we address impacts to 
feeding and energetics), Cuvier's (and all) beaked whales. Finally, new 
passive acoustic monitoring in the HSTT Study Area documents more 
extensive beaked whale distribution across the entire Study Area, 
wherever sensors are deployed (Griffiths and Barlow 2016, Rice et al. 
2020).
    Comment 22: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that NMFS underestimated serious injury and mortality 
for beaked whales. They noted the statement in the proposed rule that 
because a causal relationship between Navy MFAS use and beaked whale 
strandings has not been established in all instances, and that, in some 
cases, sonar was considered to be only one of several factors that, in 
aggregate, may have contributed to the stranding event, NMFS does ``not 
expect strandings, serious injury, or mortality of beaked whales to 
occur as a result of training activities.'' (83 FR 30007). The 
Commenter asserted that this opinion is inconsistent with best 
available science and does not take into account the fact that the 
leading explanation for the mechanism of sonar-related injuries--that 
whales suffer from bubble growth in organs that is similar to 
decompression sickness, or ``the bends'' in human divers--has now been 
supported by numerous papers. At the same time, the Commenter argued 
that NMFS fails to seriously acknowledge that sonar can seriously 
injure or kill marine mammals at distances well beyond those 
established for permanent hearing loss (83 FR 29916) and dismisses the 
risk of stranding and other mortality events (83 FR 30007) based on the 
argument that such effects can transpire only under the same set of 
circumstances that occurred during known sonar-related events--an 
assumption that is arbitrary and capricious. In conclusion, the 
Commenter argued that none of NMFS' assumptions regarding the expected 
lack of serious injury and mortality for beaked whales are supported by 
the record, and all lead to an underestimation of impacts.
    Response: The Commenter's characterization of NMFS' analysis is 
incorrect. NMFS does not disregard the fact 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. 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 strandings in the proposed rule. As noted, there are a 
suite of factors that have been associated with these specific cases of 
strandings directly 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 HSTT Study Area and during the specified activities (and which the 
Navy takes care across the world not to operate under without 
additional monitoring). There have been no documented beaked whale 
mortalities from Navy activities within the HSTT Study Area. Further, 
none of the beaked whale strandings causally associated with Navy sonar 
stranding are in the Pacific. For these reasons, NMFS does not 
anticipate that the Navy's HSTT training or testing activities will 
result in beaked whale marine mammal strandings, and none are 
authorized. Furthermore, ongoing Navy funded beaked whale monitoring at 
a heavily used training and testing area in SOCAL has not documented 
mortality or habitat abandonment by beaked whales. Passive acoustic 
detections of beaked whales have not significantly changed over ten 
years of monitoring (DiMarzio et al., 2018, 2019, 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 whale 
documented high site fidelity to this area even though the study area 
is located in one of the most used Navy areas in the Pacific (Schorr et 
al., 2018, 2020).
    Comment 23: In a comment on the 2019 HSTT proposed rule, Commenters 
noted that NMFS did not propose to authorize beaked whale mortalities 
subsequent to MFA sonar use for any of the Navy's Phase III activities 
and states that that approach is inconsistent with the tack taken for 
both TAP I and Phase II activities. The Commenters noted that for the 
2013-2018 final rule for HSTT, NMFS authorized up to 10 beaked whale 
mortality takes during the five-year period of the final rule (78 FR 
78153; December 24, 2013). They noted that NMFS justified authorizing 
those mortalities by stating that, although NMFS does not expect injury 
or mortality of any beaked whales to occur as a result of active sonar 
training exercises, there remains the potential for the operation of 
mid-frequency active sonar to contribute to the mortality of beaked 
whales (78 FR 78149; December 24, 2013). The Commenters stated that 
this justification is still applicable. The Commenters state that 
previously unrecognized sensitivities have been elucidated since the 
previous final rule was authorized (December 24, 2013), noting that 
Falcone et al., (2017) indicated that responses of Cuvier's beaked 
whales to mid-frequency active sonar within and near the Navy's 
Southern California Anti-submarine

[[Page 41805]]

Warfare Range (SOAR) were more pronounced during mid-power (i.e., 
helicopter-dipping sonar, MF4) than high-power (i.e., hull-mounted 
sonar, MF1) sonar use. The Commenters state that this indicates lower 
received levels from a less predictable source caused more marked 
responses than higher received levels from a predictable source 
traveling along a seemingly consistent course. The Commenters noted 
that since multiple species of beaked whales are regularly observed on 
the Navy's ranges in both Hawaii and Southern California, including its 
instrumented ranges, those species have been a priority for the Navy's 
monitoring program and that this indicates that research involving 
beaked whales continues to be a priority for the Navy and some of the 
whales' sensitivities to anthropogenic sound are just being discovered. 
The Commenters assert that until such time that NMFS can better 
substantiate its conclusion that the Navy's activities do not have the 
potential to kill beaked whales, taking by mortality should be included 
in all related rulemakings.
    The Commenters asserted that NMFS indicated that steep bathymetry, 
multiple hull-mounted platforms using sonar simultaneously, constricted 
channels, and strong surface ducts are not all present together in the 
HSTT Study Area during the specified activities (83 FR 66882; December 
27, 2018), and that NMFS specified that it did not authorize beaked 
whale mortalities in the 2018 HSTT final rule based on the lack of 
those factors and the lack of any strandings associated with Navy sonar 
use in the HSTT Study Area (83 FR 66882; December 27, 2018). The 
Commenters stated that this does not comport with NMFS' acknowledgement 
in the 2018 HSTT proposed rule that all five of those factors are not 
necessary for a stranding to occur (83 FR 29930; June 26, 2018). They 
go on to state that ``NMFS cannot ignore that there remains the 
potential for the operation of MFA sonar to contribute to the mortality 
of beaked whales.'' Given that the potential for beaked whale 
mortalities cannot be obviated, the Commenters recommend that NMFS 
authorize at least 10 mortality takes of beaked whales subsequent to 
MFA sonar use, consistent with the HSTT Phase II final rule.
    Response: NMFS does not disregard the fact 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. However, the Commenters are incorrect that NMFS 
must either obviate the potential for mortality or authorize it. If the 
best available science indicates that a take is reasonably likely to 
occur, then NMFS should analyze it, and will authorize it if the 
necessary findings can be made. Sometimes, especially where there is 
greater uncertainty, NMFS will analyze and authorize (where 
appropriate) impacts with a smaller likelihood of occurring to be 
precautionary and/or where an applicant specifically requests the legal 
coverage. However, the MMPA does not require NMFS to authorize impacts 
that are unlikely to occur. For example, any marine vessel has the 
potential of striking and killing a marine mammal--however, the 
probability is so low for any particular vessel that authorization for 
ship strike is neither requested nor authorized by NMFS except in cases 
where the aggregated impacts of large fleets of vessels are under 
consideration and the probability of a strike is high enough to 
meaningfully consider and to expect it could occur within the period of 
the authorization. In this case, the likelihood of a stranding 
resulting from the Navy's activity is so low as to be discountable. In 
an excess of caution, NMFS included authorization for beaked whale 
mortality by stranding in the 2013-2018 HSTT rule. However, there is no 
evidence that any such strandings subsequently actually occurred as a 
result of the Navy's activities. Each rulemaking involves review of the 
best available science independent of take that was authorized during 
previous periods based on the science available at that time. Upon 
consideration in this rulemaking of the statutory standards and the 
best available science, including full consideration of Falcone et al., 
(2017), we have determined that mortality of beaked whales is unlikely 
to occur and it is therefore not appropriate to authorize beaked whale 
mortality.
    As described in Comment 22, NMFS included a full discussion in the 
2018 HSTT proposed rule of these potential causes of mortality and 
specifically discussed the few cases where active naval sonar (in the 
U.S. or, largely, elsewhere) has either potentially contributed to or 
(as with the Bahamas example) been more definitively causally linked 
with marine mammal strandings. As noted, there are a suite of factors 
that have been associated with these specific cases of strandings 
directly associated with sonar (steep bathymetry, multiple hull-mounted 
platforms using sonar simultaneously, constricted channels, and strong 
surface ducts). The Commenters are incorrect, however, in implying that 
NMFS found that all these features must be present together--rather, we 
have suggested that all else being equal, the fewer of these factors 
that are present, the less likely they are, in combination, to lead to 
a stranding. Further, in addition to the mitigation and monitoring 
measures in place (visual monitoring, passive acoustic monitoring when 
practicable, mitigation areas including the Hawaii Island Mitigation 
Area, etc.; see the 2018 HSTT final rule Mitigation Measures and 
Monitoring sections for a full description of these measures) the Navy 
minimizes active sonar military readiness activities when these 
features are present to the maximum extent practicable to meet specific 
training or testing requirements. Additionally, as noted above, there 
have never been any strandings associated with Navy sonar use in the 
HSTT Study Area, including in the six years of Navy activities since 
the 2013 authorizations referenced by the Commenters were issued.
    The Navy acknowledges that it has funded research on the impacts of 
their activities on beaked whales in the HSTT Study Area since 2008 and 
plans to continue to do so during the seven years covered by this rule 
(DiMarzio et al., 2019, 2020; Falcone et al., 2012, 2017; Rice et al., 
2019, 2020; Schorr et al., 2014, 2019, 2020). NMFS also acknowledges 
the Commenters' statements that beaked whales have been documented 
through Navy-funded studies responding to active sonar sources. 
However, these are behavioral responses with animals eventually 
returning after the sources have departed (DiMarzio et al. 2019, 2020; 
Schorr et al. 2019, 2020). Further, controlled exposure experiments 
have not documented any beaked whale mortalities (Falcone et al., 
2017). Additionally, while beaked whales have shown avoidance responses 
to active sonar sources, to date, no population impacts have been 
detected on two of the most heavily used anti-submarine warfare 
training areas in the HSTT Study Area. This includes no significant 
change in beaked whale foraging echolocation levels on a monthly or 
annual basis as determined from over ten years of passive acoustic 
monitoring (DiMarzio et al., 2019, 2020). Furthermore, visual, photo-
identification, and satellite tagging studies at a Navy range in 
Southern California have documented repeated sightings of the same 
beaked whale individuals, sightings of new beaked

[[Page 41806]]

whale individuals, sightings of beaked whale mother-calf pairs, and 
most importantly, repeated sighting of beaked whale mothers with their 
second calf (Falcone et al., 2012; Schorr et al., 2014, 2019, 2020). 
New passive acoustic monitoring in the HSTT Study Area documents more 
extensive beaked whale distribution across the entire Study Area, 
wherever sensors are deployed (Griffiths and Barlow 2016, Rice et al., 
2019, 2020).
    For these reasons as well as the other reasons discussed more fully 
in the 2018 HSTT final rule (e.g., mitigation measures, monitoring, 
etc.), NMFS does not anticipate that the Navy's HSTT training and 
testing activities will result in beaked whale strandings and 
mortality, and therefore, no takes are authorized.
Ship Strike
    Comment 24: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that the Navy's current approach to determine the risk 
of a direct vessel collision with marine mammals is flawed and fails to 
account for the likelihood that ship strikes since 2009 were 
unintentionally underreported. The Commenter noted that vessel 
collisions are generally underreported in part because they can be 
difficult to detect, especially for large vessels and that the 
distribution, being based on reported strikes, does not account for 
this problem. Additionally, the Commenter asserted that the Navy's 
analysis does not address the potential for increased strike risk of 
non-Navy vessels as a consequence of acoustic disturbance. For example, 
some types of anthropogenic noise have been shown to induce near-
surfacing behavior in right whales, increasing the risk of ship-
strike--by not only the source vessel but potentially by third-party 
vessels in the area--at relatively moderate levels of exposure (Nowacek 
et al., 2004). An analysis based on reported strikes by Navy vessels 
per se does not account for this additional risk. In assessing ship-
strike risk, the Navy should include offsets to account for potentially 
undetected and unreported collisions.
    Response: While NMFS agrees that broadly speaking the number of 
total ship strikes may be underestimated due to incomplete information 
from other sectors (shipping, etc.), NMFS is confident that whales 
struck by Navy vessels are detected and reported, and Navy strikes are 
the numbers used in NMFS' analysis to support the authorized number of 
strikes. Navy ships have multiple Lookouts, including on the forward 
part of the ship that can visually detect a hit whale (which has 
occasionally occurred), in the unlikely event ship personnel do not 
feel the strike. The Navy's strict internal procedures and mitigation 
requirements 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. 
Accordingly, NMFS is confident that the information used to support the 
analysis is accurate and complete.
    There is no evidence that Navy training and testing activities (or 
other acoustic activities) increase the risk of nearby non-Navy vessels 
(or other nearby Navy vessels not involved in the referenced training 
or testing) striking marine mammals. More whales are struck by non-Navy 
vessels off California in areas outside of the HSTT Study Area such as 
approaches to Los Angeles and San Francisco.
    Comment 25: Commenters noted that between publication of the 2018 
HSTT proposed rule and the 2018 HSTT final rule, NMFS removed seven 
whale stocks from the list of whales the Navy determined were likely to 
be struck and killed by a vessel in the initial five-year period, 
including sei whales from the Hawaii and Eastern North Pacific stocks, 
and sperm whales from the California/Oregon/Washington (CA/OR/WA) 
stock. The Commenters asserted that NMFS has not sufficiently justified 
its decision to remove the Eastern North Pacific stock of sei whales 
and the CA/OR/WA stock of sperm whales from the list of whale stocks 
the Navy initially determined had the potential to be struck and killed 
by a vessel. They noted that while NMFS cited purportedly new 
considerations in its decision (relative likelihood of hitting one 
stock versus another and whether the Navy has ever definitively struck 
an individual from a particular stock), the underlying data doesn't 
support its conclusions as the strike probability for both stocks is 
the same as for the Eastern North Pacific Blue whale which remains on 
the list of whales that the Commenters characterize as those likely to 
die from a vessel strike. The Commenters further noted that unlike the 
other five stocks that NMFS removed from the list, individuals from 
both the Eastern North Pacific stock of sei whales and CA/OR/WA stock 
of sperm whales have been hit by a vessel in the past, and that the CA/
OR/WA stock of sperm whales is as relatively abundant as other stocks 
included in the final strike list. The Commenters asserted that the 
fact that the Navy itself has not previously hit whales from either 
stock does not alone justify removal, especially when the Navy admits 
that it was unable to identify the species of over one-third (36 
percent) of the whales it struck during the relevant time period. The 
Commenters stated that given the historic strike data and calculated 
percent likelihood of being struck as indicated in Table 43 of the 2018 
HSTT final rule, NMFS had no valid basis to conclude that Navy vessels 
are not likely to strike sei whales from the Eastern North Pacific 
stock or sperm whales from the CA/OR/WA stock.
    Response: The Commenters are correct that the probabilities 
calculated for vessel strike for each stock were considered in 
combination with the information indicating the species that the Navy 
has definitively hit in the HSTT Study Area since 1991 (since they 
started tracking vessel strikes consistently), as well as the 
information on relative abundance, total recorded strikes (by any 
vessel), and the overlay of all of this information with the Navy's 
area of testing and training activities. In Navy strikes over the last 
11 years in the HSTT Study Area (2009-2019), the species struck has 
been identified. The Eastern North Pacific stock of sei whales have 
never been struck by the Navy, have rarely been struck by other vessels 
(only one other vessel strike is known), have a low percent likelihood 
of being struck based on the SAR calculations (2.3 percent), and a very 
low relative abundance (0.007). The CA/OR/WA stock of sperm whales have 
also never been struck by the Navy, have rarely been struck by other 
vessels (only one other vessel strike is known, even given their higher 
relative abundance, as noted by the Commenter), and have a low percent 
likelihood of being struck based on the SAR calculations (2.3 percent). 
Because of these reasons, these stocks are unlikely to be struck by the 
Navy during the seven years covered by this rule.
    Comment 26: In a comment on the 2019 HSTT proposed rule, Commenters 
stated that the Navy arbitrarily failed to increase its vessel strike 
estimate upwards to account for the greater number of at-sea days. They 
stated that applying the historic strike rate of 0.00006 whales per day 
by the increased number of at-sea days over seven years (assumed by the 
Commenters to be 31,728) the new base strike estimate should be 1.9 
whales rather than 1.34 whales. They further state that applying the 
Poisson distribution to this new base strike estimate indicates that 
there is an 8 percent chance that 4 large whales

[[Page 41807]]

will be hit during the extended seven-year time period. They asserted 
that NMFS neither considers nor explains why the chance of striking 4 
whales is not considered likely during the extended seven-year period 
of authorization, and how this may impact overall strike probability 
assessments for individual whale stocks and that NMFS' reliance on a 
total vessel strike number derived for only five years of HSTT 
activities to authorize those activities to continue for seven years is 
arbitrary and capricious.
    Response: Based on the revised seven-year ship strike analysis that 
was used in the 2019 HSTT proposed rule (which incorporates all ship 
strike data in the HSTT Study Area from 2009 through 2018, rather than 
2016 as previously analyzed for the 2017 Navy application), the strike 
rate is 0.000047 whales strikes per day at sea. Over a seven year 
period the number of at-sea days is 31,729, leading to an estimate of 
1.5 whales over seven years. When applying the Poisson distribution to 
this strike estimate, as reported in the Vessel Strike section, the 
probability analysis concluded that there was a 22 percent chance that 
zero whales would be struck by Navy vessels over the seven-year period, 
and a 33.5, 25.1, 12.5, and 4.7 percent chance that one, two, three, or 
four whales, respectively, would be struck over the seven-year period. 
The probability of the Navy striking up to three large whales over the 
seven-year period (which is a 12.5 percent chance) as analyzed for this 
final rule using updated Navy vessel strike data and at-sea days is 
very close to the probability of the Navy striking up to three large 
whales over five years (which was a 10 percent chance). As the 
probability of striking three large whales does not differ 
significantly from the 2018 HSTT final rule, and the probability of 
striking four large whales over seven years remains very low to the 
point of being unlikely (less than 5 percent), the Navy has requested, 
and we are authorizing, no change in the number of takes by serious 
injury or mortality due to vessel strikes over the seven-year period of 
this rule. Furthermore, these are statistical calculations of 
probabilities of strike that do not factor in Navy operating procedures 
and mitigations to avoid large whales. There has not been an actual 
Navy ship strike to a large whale in the HSTT Study Area since 2010. 
This lack of vessel strikes is factored into the revised seven-year 
statistical calculation and is reflected in the probabilities shown 
above.
    Comment 27: In a comment on the 2019 HSTT proposed rule, Commenters 
asserted that it was arbitrary and capricious for NMFS to assume that 
the annualized strike rate for each of the six large whales species 
that NMFS determined have the potential to be struck would decrease 
over the seven-year extension period as compared to the initial five-
year period. They asserted that given that the same level of training 
and testing activities will continue under the proposed extension rule 
for a longer amount of time, at minimum, the annual strike rate should 
remain constant at the levels authorized in the 2018 HSTT final rule. 
They asserted that NMFS' arbitrary reduction of the annual strike rate 
precludes reasoned analysis of whether vessel strikes will inflict non-
negligible impacts on whale stocks. The Commenters noted of particular 
concern were the CA/OR/WA stock of humpback whales and the Eastern 
North Pacific stock of blue whales, both of which suffer annual human-
caused mortality at levels much higher than the established PBR 
(Potential Biological Removal; as represented by the negative residual 
PBR numbers). They asserted that by definition, any mortality above PBR 
will decrease a marine mammal stock below its optimum sustainable 
population, thereby inducing population level, non-negligible impacts. 
The Commenters asserted that NMFS' analysis does not sufficiently 
consider the effects of further increasing mortality above established 
PBR levels, especially in light of the fact that annual take estimates 
have been arbitrarily reduced. They noted that an additional 0.2 
mortalities per year is a potentially significant stressor for the 
populations of both the CA/OR/WA stock of humpback whales and the 
Eastern North Pacific stock of blue whales, and that NMFS failed to 
adequately consider this potential through population viability 
analyses or other accepted method for determining long-term population 
level effects. They further asserted that NMFS does not separately 
address the possibility of striking and killing a reproductive female. 
They stated that NMFS's failure to adequately consider the effects of 
these additional mortalities, including the potential death of a 
reproductive female, is arbitrary and capricious.
    Response: In the 2018 HSTT final rule, potential mortalities of 
three whales due to ship strike were spread over five years and 
therefore, the annual average of 0.4 gray whales (Eastern North Pacific 
stock), fin whales (CA/OR/WA stock), and humpback whales (Central North 
Pacific stock) and an annual average of 0.2 blue whales (Eastern North 
Pacific stock), humpback whales (CA/OR/WA stock, Mexico DPS), and sperm 
whales (Hawaii stock) (i.e., one, or two, take(s) over five years 
divided by five to get the annual number) were expected to potentially 
occur and were authorized. NMFS did not arbitrarily reduce the 
annualized strike rate in the seven-year analysis. Following these same 
methods, as the three total potential mortalities are now spread over 
seven years rather than five, an annual average of 0.29 gray whales 
(Eastern North Pacific stock), fin whales (CA/OR/WA stock), and 
humpback whales (Central North Pacific stock) and an annual average of 
0.14 blue whales (Eastern North Pacific stock), humpback whales (CA/OR/
WA stock, Mexico DPS), and sperm whales (Hawaii stock) as described in 
Table 16 (i.e., one, or two, take(s) over seven years divided by seven 
to get the annual number) are expected to potentially occur and are 
authorized.
    As explained in the Serious Injury or Mortality subsection of the 
Negligible Impact Analysis and Determination section of the 2018 HSTT 
final rule and this rule, in the commercial fisheries setting for ESA-
listed marine mammals (which is similar to the non-fisheries incidental 
take setting, in that a negligible impact determination is required 
that is based on the assessment of take caused by the activity being 
analyzed), NMFS may find the impact of the authorized take from a 
specified activity to be negligible even if total human-caused 
mortality exceeds PBR, if the authorized mortality is less than 10 
percent of PBR and management measures are being taken to address 
serious injuries and mortalities from the other activities causing 
mortality (i.e., other than the specified activities covered by the 
incidental take authorization in consideration). When those 
considerations are applied in the section 101(a)(5)(A) context here, 
the authorized lethal take (0.14 annually) of humpback whales from the 
CA/OR/WA stock, and blue whales from the Eastern North Pacific stock 
are less than 10 percent of PBR (33.4 for humpback whales from the CA/
OR/WA stock and 2.1 for blue whales from the Eastern North Pacific 
stock) and there are management measures in place to address the 
mortality and serious injury from the activities other than those the 
Navy is conducting. For the complete discussion of how NMFS carefully 
considered potential mortalities from the Navy's activities in light of 
PBR levels, including an explanation for why mortality above PBR will 
not necessarily induce population-level non-negligible

[[Page 41808]]

impacts, see the discussion in this rule and the 2018 HSTT final rule.
    NMFS acknowledges that the removal of a reproductive female (or any 
female) could be more impactful to the status of a population than the 
removal of a male. However, the PBR framework that supports the 
negligible impact finding inherently considers the likelihood that the 
human-caused mortalities being considered may consist of a random 
distribution of individuals of different sex in different life stages. 
Also, beyond the low likelihood of striking a whale at all, the 
likelihood of hitting a reproductive female is even lower.

Mitigation and Monitoring

Least Practicable Adverse Impact Determination
    Comment 28: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that deaths of, or serious injuries to marine mammals 
that occur pursuant to activities conducted under an incidental take 
authorization, while perhaps negligible to the overall health and 
productivity of the species or stock and of little consequence at that 
level, nevertheless are clearly adverse to the individuals involved and 
results in some quantifiable (though negligible) adverse impact on the 
population; it reduces the population to some degree. Under the least 
practicable adverse impact requirement, and more generally under the 
purposes and policies of the MMPA, the Commenter asserted that Congress 
embraced a policy to minimize, whenever practicable, the risk of 
killing or seriously injuring a marine mammal incidental to an activity 
subject to section 101(a)(5)(A), including providing measures in an 
authorization to eliminate or reduce the likelihood of lethal taking. 
The Commenter recommended that NMFS address this point explicitly in 
its 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.
    Response: NMFS disagrees that it is necessary or helpful to 
explicitly address the point the Commenter raises in the discussion on 
the least practicable adverse impact standard. It is always NMFS' 
practice to mitigate 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. Further, we do 
not understand the problem that the Commenter's recommendation is 
attempting to fix. Applicants generally do not express reluctance to 
mitigate mortality, and we believe that modifications of this nature 
would confuse the issue.
    Comment 29: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that NMFS address the habitat component of the 
least practicable adverse impact provision in greater detail. It 
asserted that NMFS' discussion of critical habitat, marine sanctuaries, 
and BIAs in the proposed rule is not integrated with the discussion of 
the least practicable adverse impact standard. It would seem that, 
under the least practicable adverse impact provision, adverse impacts 
on important habitat should be avoided whenever practicable. Therefore, 
to the extent that activities would be allowed to proceed in these 
areas, NMFS should explain why it is not practicable to constrain them 
further.
    Response: 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., calving areas in Hawaii, feeding areas 
in SOCAL). In addition to being delineated based on physical features 
that drive habitat function (e.g., bathymetric features among others 
for some BIAs), the high densities and concentration of certain 
important behaviors (e.g., feeding) 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.
    Comment 30: In a comment on the 2018 HSTT proposed rule, 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. In this regard, the Commenter asserted that it 
seems as though the proposed ``effectiveness'' criterion more 
appropriately fits as an element of practicability and should be 
addressed under that prong of the analysis. In other words, a measure 
not expected to be effective should not be considered a practicable 
means of reducing impacts.
    Response: In the Mitigation Measures section, NMFS has explained in 
detail our interpretation of the least practicable adverse impact 
standard, the rationale for our interpretation, and our approach for 
implementing our interpretation. The ability of a measure to reduce 
effects on marine mammals is entirely related to its ``effectiveness'' 
as a measure, whereas the effectiveness of a measure is not connected 
to its practicability. The Commenter provides no support for its 
argument, and NMFS has not implemented the suggestion.
    Comment 31: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that NMFS recast its conclusions to provide 
sufficient detail as to why additional measures either are not needed 
(i.e., there are no remaining adverse impacts) or would not be 
practicable to implement. The Commenter stated that the most concerning 
element of NMFS' implementation of the least practicable adverse impact 
standard is its suggestion that the mitigation measures proposed by the 
Navy will ``sufficiently reduce impacts on the affected mammal species 
and stocks and their habitats'' (83 FR 11045). That phrase suggests 
that NMFS is applying a ``good-enough'' standard to the Navy's 
activities. Under the statutory criteria, however, those proposed 
measures are ``sufficient'' only if they have either (1) eliminated all 
adverse impacts on marine mammal species and stocks and their habitat 
or (2) if adverse impacts remain, it is not practicable to reduce them 
further.
    Response: The statement that the Commenter references does not 
indicate that NMFS applies a ``good-enough'' standard to determining 
least practicable adverse impact. Rather, it indicates that the 
mitigation measures are sufficient to meet the statutory legal 
standard. In addition, as NMFS has explained in our description of the 
least practicable adverse impact standard, NMFS does not view the 
necessary analysis through the yes/no lens that the Commenter seeks to 
prescribe. Rather, NMFS' least practicable adverse impact analysis 
considers both the reduction of adverse effects and their 
practicability.

[[Page 41809]]

Further, since the 2018 HSTT proposed rule was published, the Navy and 
NMFS evaluated additional measures in the context of both their 
practicability and their ability to further reduce impacts to marine 
mammals and have determined that the addition of several measures (see 
Mitigation Measures section) is appropriate. Regardless, beyond these 
new additional measures, where the Navy's HSTT activities are 
concerned, the Navy has indicated that further procedural or area 
mitigation of any kind (beyond that prescribed in this final rule) 
would be impracticable. NMFS has reviewed documentation and analysis 
provided by the Navy explaining how and why specific procedural and 
geographic based mitigation measures impact practicability, and NMFS 
concurs with these assessments and has determined that the mitigation 
measures outlined in the final rule satisfy the statutory standard and 
that any adverse impacts that remain cannot practicably be further 
mitigated.
    Comment 32: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that any ``formal interpretation'' of the least 
practicable adverse impact standard by NMFS be issued in a stand-alone, 
generally applicable rulemaking (e.g., in amendments to 50 CFR 216.103 
or 216.105) or in a separate policy directive, rather than in the 
preambles to individual proposed rules.
    Response: We appreciate the Commenter's recommendation and may 
consider the recommended approach in the future. We note, however, that 
providing relevant explanations in a proposed incidental take rule is 
an effective and efficient way to provide information to the reader and 
solicit focused input from the public, and ultimately affords the same 
opportunities for public comment as a stand-alone rulemaking would. 
NMFS has provided similar explanations of the least practicable adverse 
impact standard in other recent section 101(a)(5)(A) rules, including: 
U.S. Navy Operations of Surveillance Towed Array Sensor System Low 
Frequency Active (SURTASS LFA) Sonar; Geophysical Surveys Related to 
Oil and Gas Activities in the Gulf of Mexico; and the final rule for 
U.S. Navy Training and Testing Activities in the Atlantic Fleet Study 
Area.
    Comment 33: In a comment on the 2018 HSTT proposed rule, 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: It ``cannot 
just parrot what the Navy says.''
    Response: 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. Regarding the comment about 
mitigation of habitat impacts, it has been addressed above in the 
response to Comment 29.
    When a suggested or recommended mitigation measure 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 2018 HSTT final 
rule. First, the type of mitigation required varies 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. 
Examples of NMFS' analysis on this issue appear throughout the rule. 
For instance, while it was not practicable for the Navy to include a 
mitigation area for the Tanner-Cortes blue whale BIA, the Navy did 
agree to expand mitigation protection to all of the other blue whale 
BIAs in the SOCAL region. Additionally, while the Navy cannot alleviate 
all training in the mitigation areas that protect small resident 
odontocete populations in Hawaii, it has further expanded the 
protections in those areas such that it does not use explosives or MFAS 
in the areas (MF1 bin in both areas, MF4 bin in the Hawaii Island 
area).
    Nonetheless, NMFS agrees 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, 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 HSTT Study Area. Discussion regarding specific 
recommendations for mitigation measures provided by the Commenter on 
the proposed rule are discussed separately.
Procedural Mitigation Effectiveness and Recommendations
    Comment 34: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that the Navy's proposed mitigation zones are similar 
to the zones previously used during Phase II activities and are 
intended, based on the Phase III HSTT DEIS/OEIS, to avoid the potential 
for marine mammals to be exposed to levels of sound that could result 
in injury (i.e., PTS). However, the Commenter believed that Phase III 
proposed mitigation zones would not protect various functional hearing 
groups from PTS. For example, the mitigation zone for an explosive 
sonobuoy is 549 m but the mean PTS zones range from 2,113-3,682 m for 
HF. Similarly, the mitigation zone for an explosive torpedo is 1,920 m 
but the mean PTS zones range from 7,635-10,062 m for HF, 1,969-4,315 m 
for LF, and 3,053-3,311 for PW. The appropriateness of such zones is 
further complicated by platforms firing munitions (e.g., for missiles 
and rockets) at targets that are 28 to 139 km away from the firing 
platform. An aircraft would clear the target area well before it 
positions itself at the launch location and launches the missile or 
rocket.

[[Page 41810]]

Ships, on the other hand, do not clear the target area before launching 
the missile or rocket. In either case, marine mammals could be present 
in the target area unbeknownst to the Navy at the time of the launch.
    Response: NMFS is aware that some mitigation zones do not fully 
cover the area in which an animal from a certain hearing group may 
incur PTS. For this small subset of circumstances, NMFS discussed 
potential enlargement of the mitigation zones with the Navy, but 
concurred with the Navy's assessment that further enlargement would be 
impracticable. Specifically, the Navy explained that, as discussed in 
Chapter 5 (Mitigation) of the 2018 HSTT FEIS/OEIS, for explosive 
mitigation zones any additional increases in mitigation zone size 
(beyond what is depicted for each explosive activity), or additional 
observation requirements, would be impracticable to implement due to 
implications for safety, sustainability, the Navy's ability to meet 
Title 10 requirements to successfully accomplish military readiness 
objectives, and the Navy's ability to conduct testing associated with 
required acquisition milestones or as required to meet operational 
requirements. Additionally, Navy Senior Leadership has approved and 
determined that the mitigation detailed in Chapter 5 (Mitigation) of 
the 2018 HSTT FEIS/OEIS provides the greatest extent of protection that 
is practicable to implement. NMFS has analyzed the fact that despite 
these mitigation measures, some Level A harassment may occur in some 
circumstances; the Navy is authorized for these takes by Level A 
harassment.
    Comment 35: In a comment on the 2018 HSTT proposed rule, a 
Commenter made several comments regarding visual and acoustic detection 
as related to mitigating impacts that can cause injury. The Commenter 
noted that the Navy indicated in the 2018 HSTT DEIS/OEIS that Lookouts 
would not be 100 percent effective at detecting all species of marine 
mammals for every activity because of 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). The Navy has been collaborating with researchers at the 
University of St. Andrews to study Navy Lookout effectiveness and the 
Commenter anticipates that the Lookout effectiveness study will be very 
informative once completed, but notes that in the interim, the 
preliminary data do provide an adequate basis for taking a 
precautionary approach. The Commenter believed that rather than simply 
reducing the size of the mitigation zones it plans to monitor, the Navy 
should supplement its visual monitoring efforts with other monitoring 
measures including passive acoustic monitoring.
    The Commenter suggested that sonobuoys could be deployed with the 
target in the various target areas prior to the activity. This approach 
would allow the Navy to better determine whether the target area is 
clear and remains clear until the munition is launched.
    Although the Navy indicated that it was continuing to improve its 
capabilities for using range instrumentation to aid in the passive 
acoustic detection of marine mammals, it also stated that it didn't 
have the capability or resources to monitor instrumented ranges in real 
time for the purpose of mitigation. That capability clearly exists. 
While available resources could be a limiting factor, the Commenter 
notes that personnel who monitor the hydrophones on the operational 
side do have the ability to monitor for marine mammals as well. The 
Commenter has supported the use of the instrumented ranges to fulfill 
mitigation implementation for quite some time and contends that 
localizing certain species (or genera) provides more effective 
mitigation than localizing none at all.
    The Commenter recommended that NMFS require the Navy to use passive 
and active acoustic monitoring, whenever practicable, to supplement 
visual monitoring during the implementation of its mitigation measures 
for all activities that have the potential to cause injury or mortality 
beyond those explosive activities for which passive acoustic monitoring 
already was proposed, including those activities that would occur on 
the Southern California Offshore Range (SCORE) and Pacific Missing 
Range Facility (PMRF) ranges.
    Response: For explosive mitigation zones, any additional increases 
in mitigation zone size (beyond what is depicted for each explosive 
activity) or observation requirements would be impracticable to 
implement due to implications for safety, sustainability, and the 
Navy's ability to meet Title 10 requirements to successfully accomplish 
military readiness objectives. We do note, however, that since the 2018 
HSTT proposed rule, the Navy has committed to implementing pre-event 
observations for all in-water explosives events (including some that 
were not previously monitored) and to using additional platforms if 
available in the vicinity of the detonation area to help with this 
monitoring.
    As discussed in the comment (referencing the use of sonobuoys or 
hydrophones), 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). For 
other explosive events, there are no platforms participating that 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 5.5.3 (Active 
and Passive Acoustic Monitoring Devices) of the 2018 HSTT FEIS/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. Additionally, diverting platforms that have passive 
acoustic monitoring platforms 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. However, the Navy's instrumented ranges were not developed 
for the purpose of mitigation. As discussed above, 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. A more detailed 
discussion of the limitations for on-range passive acoustic detection 
as real-time mitigation is provided in Comment 42 and is not 
practicable for the Navy. For example, beaked whales produce highly 
directed echolocation clicks that are difficult to simultaneously 
detect on multiple hydrophones within the instrumented range at PMRF; 
therefore, there is a high probability that a vocalizing animal would 
be assigned a false location on the range (i.e., the Navy would not be 
able to verify its presence in a mitigation zone). Although the Navy is 
continuing to improve its

[[Page 41811]]

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 5.5.3 (Active and Passive Acoustic Monitoring Devices) of the 
2018 HSTT FEIS/OEIS.
    Comment 36: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that NMFS require the Navy to conduct additional 
pre-activity overflights before conducting any activities involving 
detonations barring any safety issues (e.g., low fuel), as well as 
post-activity monitoring for activities involving medium- and large 
caliber projectiles, missiles, rockets, and bombs.
    Response: The Navy has agreed to implement pre-event observation 
mitigation, as well as post-event observation, for all in-water 
explosive event mitigation measures. 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.
    Comment 37: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that the Navy implement larger shutdown zones.
    Response: The Navy mitigation zones represent the maximum surface 
area the Navy can effectively observe based on the platform involved, 
number of personnel that will be involved, and the number and type of 
assets and resources available. As mitigation zone sizes increase, the 
potential for observing marine mammals and thus reducing impacts 
decreases, because the number of observers cannot increase although the 
area to observe increases. For instance, if a mitigation zone increases 
from 1,000 to 2,000 yd, the area that must be observed increases four-
fold. NMFS has analyzed the Navy's required mitigation and found that 
it will effect the least practicable adverse impact. The Navy's 
mitigation measures consider both the need to reduce potential impacts 
and the ability to provide effective observations throughout a given 
mitigation zone. To implement these mitigation zones, Navy Lookouts are 
trained to use a combination of unaided eye and optics as they search 
the surface around a vessel, detonation location, or applicable sound 
source. In addition, there are other Navy personnel on a given bridge 
watch (in addition to designated Lookouts), who are also constantly 
watching the water for safety of navigation and marine mammals. Takes 
that cannot be mitigated are analyzed and authorized provided the 
necessary findings can be made.
    Comment 38: In a comment on the 2018 HSTT proposed rule, Commenters 
stated that NMFS should cap the maximum level of activities each year.
    Response: The Commenters offer no rationale for why a cap is needed 
and nor do they suggest what an appropriate cap might be. The Navy is 
responsible under Title 10 for conducting the needed amount of testing 
and training to maintain military readiness, which is what they have 
proposed and NMFS has analyzed. Further, the MMPA states that NMFS 
shall issue MMPA authorizations if the necessary findings can be made, 
as they have been here. Importantly, as described in the Mitigation 
Areas section, the Navy will limit activities (active sonar, explosive 
use, etc.) to varying degrees in multiple areas that are important to 
sensitive species or for critical behaviors in order to minimize 
impacts that are more likely to lead to adverse effects on rates of 
recruitment or survival.
    Comment 39: In a comment on the 2018 HSTT proposed rule, a 
Commenter suggested the Navy could improve observer effectiveness 
through the use of NMFS-certified marine mammal observers.
    Response: The Navy currently requires at least one qualified 
Lookout on watch at all times a vessel is underway. In addition, on 
surface ships with hull-mounted sonars during sonar events, the number 
increases with two additional Lookouts on the forward portion of the 
vessel (i.e., total of three Lookouts). Furthermore, unlike civilian 
commercial ships, there are additional bridge watch standers on Navy 
ships viewing the water during all activities. The Navy's Marine 
Species Awareness training that all bridge watchstanders including 
Lookouts take has been reviewed and approved by NMFS. This training is 
conducted annually and prior to MTEs. In addition, unit-based passive 
acoustic detection is used when available and appropriate.
    As we understand from the Navy, mandating NMFS-certified marine 
mammal observers on all platforms would require setting up and 
administering a certification program, providing security clearance for 
certified people, ensuring that all platforms are furnished with these 
individuals, and housing these people on ships for extended times from 
weeks to months. This would be an extreme logistical burden on 
realistic training. The requirement for additional non-Navy observers 
would provide little additional benefit, especially at the near ship 
mitigation ranges for mid-frequency active sonars on surface ships 
(<1,000 yds), and would not be significantly better than the current 
system developed by the Navy in consultation with NMFS.
    The purpose of Navy Lookouts is to provide sighting information for 
marine mammals and other protected species, as well as other boats and 
vessels in the area, in-water debris, and other safety of navigation 
functions. During active sonar use, additional personnel are assigned 
for the duration of the sonar event. In addition, the other Navy 
personnel on a given bridge watch along with designated Lookouts are 
also constantly watching the water for safety of navigation and marine 
mammals.
    Navy training and testing activities often occur simultaneously and 
in various regions throughout the HSTT Study Area, with underway time 
that could last for days or multiple weeks at a time. The pool of 
certified marine mammal observers across the U.S. West Coast is rather 
limited, with many already engaged in regional NMFS survey efforts. 
Relative to the number of dedicated MMOs that would be required to 
implement this condition, as of July 2018, there are approximately 22 
sonar-equipped Navy ships (i.e., surface ships with hull-mounted active 
sonars) stationed in San Diego. Six additional vessels from the Pacific 
Northwest also transit to Southern California for training (28 ships 
times 2 observers per watch times 2 watches per day = minimum of 112 
observers). There are currently not enough certified marine mammal 
observers to cover these Navy activities, even if it were practicable 
for the other reasons explained above.
    Senior Navy commands in the Pacific continuously reemphasize the 
importance of Lookout responsibilities to all ships. Further, the Navy 
has an ongoing study in which certified Navy civilian scientist 
observers embark periodically on Navy ships in support of a comparative 
Lookout effectiveness study. Results from this study will be used to 
make recommendations for further improvements to Lookout training.
    Additionally, we note that the necessity to include trained NMFS-
approved PSOs on Navy vessels, while adding little or no additional 
protective or data-gathering value, would be very expensive and those 
costs would need to be offset--most likely through reductions in the 
budget for Navy monitoring, through which invaluable data is gathered.
    Comment 40: In a comment on the 2018 HSTT proposed rule, Commenters 
stated that NMFS should consider

[[Page 41812]]

increasing the exclusion zone to the 120 dB isopleth because some 
animals are sensitive to sonar at low levels of exposure.
    Response: First, it is important to note that the Commenters are 
suggesting that NMFS require mitigation that would eliminate all take, 
which is not what the applicable standard requires. Rather, NMFS is 
required to put in place measures that effect the ``least practicable 
adverse impact.'' Separately, NMFS acknowledges that some marine 
mammals may respond to sound at 120 dB in some circumstances; however, 
based on the best available data, only a subset of those exposed at 
that low level respond in a manner that would be considered harassment 
under the MMPA. NMFS and the Navy have quantified those individuals of 
certain stocks where appropriate, analyzed the impacts, and authorized 
take where needed. Further, NMFS and the Navy have identified exclusion 
zone sizes that are best suited to minimize impacts to marine mammal 
species and stocks and their habitat while also being practicable (see 
Mitigation Measures section).
    Comment 41: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that NMFS should impose a 10-kn ship speed limit in 
biologically important areas and critical habitat for marine mammals to 
reduce vessel strikes. The Commenter also specifically referenced this 
measure in regard to humpback whales and blue whales.
    Response: This issue also is addressed elsewhere in the Comments 
and Responses section for specific mitigation areas. However, generally 
speaking, it is impracticable (because of impacts to mission 
effectiveness) to further reduce ship speeds for Navy activities, and, 
moreover, given the maneuverability of Navy ships at higher speeds and 
the presence of effective Lookouts, any further reduction in speed 
would reduce the already low probability of ship strike little, if any. 
The Navy is unable to impose a 10-kn ship speed limit because it would 
not be practical to implement and would impact the effectiveness of 
Navy's activities by putting constraints on training, testing, and 
scheduling. The Navy requires flexibility in use of variable ship 
speeds for training, testing, operational, safety, and engineering 
qualification requirements. Navy ships typically use the lowest speed 
practical given individual mission needs. NMFS has reviewed the Navy's 
analysis of these additional restrictions and the impacts they would 
have on military readiness and concurs with the Navy's assessment that 
they are impracticable.
    The main driver for ship speed reduction is reducing the 
possibility and severity of ship strikes to large whales. However, even 
given the wide ranges of speeds from slow to fast that Navy ships must 
use to meet training and testing requirements, the Navy has a very low 
strike history to large whales in Southern California and Hawaii, with 
no whales struck by the Navy from 2010-2019. There have been no whales 
struck in Hawaii since 2008 (4 whales were struck between 2000 and 
2008). Current Navy Standard Operating Procedures and mitigations 
require a minimum of at least one Lookout on duty while underway (in 
addition to bridge watch personnel) and, so long as safety of 
navigation is maintained, to keep 500 yards away from large whales and 
200 yards away from other marine mammals (except for bow-riding 
dolphins and pinnipeds hauled out on shore or man-made navigational 
structures, port structures, and vessels). Furthermore, there is no 
Navy ship strike of a marine mammal on record in SOCAL that has 
occurred in the coastal area (~40 nmi from shore), which is where speed 
restrictions are most requested. Finally, the most recent model 
estimate of the potential for civilian ship strike risk to blue, 
humpback, and fin whales off the coast of California found the highest 
risk near San Francisco and Long Beach associated with commercial ship 
routes to and from those ports (Rockwood et al., 2017). There was no 
indication of a similar high risk to these species off San Diego, where 
the HSTT Study Area occurs.
    Previously, the Navy commissioned a vessel density and speed report 
based on an analysis of Navy ship traffic in the HSTT Study Area 
between 2011 and 2015. Median speed of all Navy vessels within the HSTT 
Study Area is typically already low, with median speeds between 5 and 
12 knots. Further, the presence and transits of commercial and 
recreational vessels, annually numbering in the thousands, poses a more 
significant risk to large whales than the presence of Navy vessels. The 
Vessel Strike subsection of the Estimated Take of Marine Mammals 
section of this rule and the 2018 HSTT FEIS/OEIS Chapter 3 (Affected 
Environment and Environmental Consequences) Section 3.7.3.4.1 (Impacts 
from Vessels and In-Water Devices) and Appendix K, Section K.4.1.6.2 
(San Diego (Arc) Blue Whale Feeding Area Mitigation Considerations), 
explain the important differences between most Navy vessels and their 
operation and commercial ships that make Navy vessels much less likely 
to strike a whale.
    When developing Phase III mitigation measures, the Navy analyzed 
the potential for implementing additional types of mitigation, such as 
vessel speed restrictions within the HSTT Study Area. The Navy 
determined that based on how the training and testing activities will 
be conducted within the HSTT Study Area, vessel speed restrictions 
would be incompatible with practicability criteria for safety, 
sustainability, and training and testing missions, as described in 
Chapter 5 (Mitigation), Section 5.3.4.1 (Vessel Movement) of the 2018 
HSTT FEIS/OEIS. NMFS fully reviewed this analysis and concurs with the 
Navy's conclusions.
    Comment 42: In a comment on the 2018 HSTT proposed rule, Commenters 
stated that NMFS should improve detection of marine mammals with 
restrictions on low-visibility activities and alternative detection 
such as thermal or acoustic methods.
    Response: The Navy has compiled information related to the 
effectiveness of certain equipment to detect marine mammals in the 
context of their activities, as well as the practicality and effect on 
mission effectiveness of using various equipment. NMFS has reviewed 
this evaluation and concurs with the characterizations and the 
conclusions below.
    Low visibility--Anti-submarine warfare training involving the use 
of mid-frequency active sonar typically involves the periodic use of 
active sonar to develop the ``tactical picture,'' or an understanding 
of the battle space (e.g., area searched or unsearched, presence of 
false contacts, and an understanding of the water conditions). 
Developing the tactical picture can take several hours or days, and 
typically occurs over vast waters with varying environmental and 
oceanographic conditions. Training during both high visibility (e.g., 
daylight, favorable weather conditions) and low visibility (e.g., 
nighttime, inclement weather conditions) is vital because sonar 
operators must be able to understand the environmental differences 
between day and night and varying weather conditions and how they 
affect sound propagation and the detection capabilities of sonar. 
Temperature layers move up and down in the water column and ambient 
noise levels can vary significantly between night and day, affecting 
sound propagation and how sonar systems are operated. Reducing or 
securing power in low-visibility conditions as a mitigation would 
affect a commander's ability to develop the tactical picture and would

[[Page 41813]]

prevent sonar operators from training in realistic conditions. Further, 
during integrated training multiple vessels and aircraft may 
participate in an exercise using different dimensions of warfare 
simultaneously (e.g., submarine warfare, surface warfare, air warfare, 
etc.). If one of these training elements were adversely impacted (e.g., 
if sonar training reflecting military operations were not possible), 
the training value of other integrated elements would also be degraded. 
Additionally, failure to test such systems in realistic military 
operational scenarios increases the likelihood these systems could fail 
during military operations, thus unacceptably placing Sailors' lives 
and the Nation's security at risk. Some systems have a nighttime 
testing requirement; therefore, these tests cannot occur only in 
daylight hours. Reducing or securing power in low visibility conditions 
would decrease the Navy's ability to determine whether systems are 
operationally effective, suitable, survivable, and safe for their 
intended use by the fleet even in reduced visibility or difficult 
weather conditions.
    Thermal detection--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. 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 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 such 
as 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 system 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.)
    Finally, 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.
    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 HSTT 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 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 to the 
Navy's ability to implement its established observation and mitigation 
requirements. The mitigation measures discussed in Chapter 5 
(Mitigation), Section 5.3 (Procedural Mitigation to be Implemented) of 
the 2018 HSTT FEIS/OEIS 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

[[Page 41814]]

information on the exact timing and scope of these studies is not 
currently available (still in 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.
    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.
    Passive Acoustic Monitoring--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). For other explosive events, there are no platforms 
participating that have passive acoustic monitoring capabilities. 
Adding a passive acoustic monitoring capability (either by adding a 
passive acoustic monitoring device 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 Chapter 5 
(Mitigation), Section 5.5.3 (Active and Passive Acoustic Monitoring 
Devices) of the 2018 HSTT FEIS/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. Additionally, diverting 
platforms that have passive acoustic monitoring platforms would impact 
their ability to meet their Title 10 requirements and reduce the 
service life of those systems.
    The use of real-time passive acoustic monitoring (PAM) for 
mitigation at the Southern California Anti-submarine Warfare Range 
(SOAR) exceeds the capability of current technology. The Navy has a 
significant research investment in the Marine Mammal Monitoring on Navy 
Ranges (M3R) system at three ocean locations including SOAR. However, 
this system was designed and intended to support marine mammal research 
for select species, and not as a mitigation tool. Marine mammal PAM 
using instrumented hydrophones is still under development and while it 
has produced meaningful results for marine species monitoring, 
abundance estimation, and research, it was not developed for nor is it 
appropriate for real-time mitigation. The ability to detect, classify, 
and develop an estimated position (and the associated area of 
uncertainty) differs across species, behavioral context, animal 
location vs. receiver geometry, source level, etc. Based on current 
capabilities, and given adequate time, vocalizing animals within an 
indeterminate radius around a particular hydrophone are detected, but 
obtaining an estimated position for all individual animals passing 
through a predetermined area is not assured. Detecting vocalizations on 
a hydrophone does not determine whether vocalizing individuals would be 
within the established mitigation zone in the timeframes required for 
mitigation. Since detection ranges are generally larger than current 
mitigation zones for many activities, this would unnecessarily delay 
events due to uncertainty in the animal's location and put at risk 
event realism.
    Furthermore, PAM at SOAR does not account for animals not 
vocalizing. For instance, there have been many documented occurrences 
during PAM verification testing at SOAR of small boats on the water 
coming across marine mammals such as baleen whales that were not 
vocalizing and therefore not detected by the range hydrophones. Animals 
must vocalize to be detected by PAM; the lack of detections on a 
hydrophone may give the false impression that the area is clear of 
marine mammals. The lack of vocalization detections is not a direct 
measure of the absence of marine mammals. If an event were to be moved 
based upon low-confidence localizations, it may inadvertently be moved 
to an area where non-vocalizing animals of undetermined species are 
present.
    To develop an estimated position for an individual, it must be 
vocalizing and its vocalizations must be detected on at least three 
hydrophones. The hydrophones must have the required bandwidth, and 
dynamic range to capture the signal. In addition, calls must be 
sufficiently loud so as to provide the required signal to noise ratio 
on the surrounding hydrophones. Typically, small odontocetes echolocate 
with a directed beam that makes detection of the call on multiple 
hydrophones difficult. Developing an estimated position of selected 
species requires the presence of whistles which may or may not be 
produced depending on the behavioral state. Beaked whales at SOAR 
vocalize only during deep foraging dives which occur at a rate of 
approximately 10 per day. They produce highly directed echolocation 
clicks that are difficult to simultaneously detect on multiple 
hydrophones. Current real-time systems cannot follow individuals and at 
best produce sparse positions with multiple false locations. The 
position estimation process must occur in an area with hydrophones 
spaced to allow the detection of the same echolocation click on at 
least three hydrophones. Typically, a spacing of less than 4 km in 
water depths of approximately 2 km is preferred. In the absence of 
detection,

[[Page 41815]]

the analyst can only determine with confidence if a group of beaked 
whales is somewhere within 6 km of a hydrophone. Beaked whales produce 
stereotypic click trains during deep (<500 m) foraging dives. The 
presence of a vocalizing group can be readily detected by an analyst by 
examining the click structure and repetition rate. However, estimating 
position is possible only if the same train of clicks is detected on 
multiple hydrophones which is often precluded by the animal's narrow 
beam pattern. Currently, this is not an automated routine.
    In summary, the analytical and technical capabilities required to 
use PAM such as M3R at SOAR as a required mitigation tool are not 
sufficiently robust to rely upon due to limitations with near real-time 
classification and determining estimated positions. The level of 
uncertainty as to a species presence or absence and location are too 
high to provide the accuracy required for real-time mitigation. As 
discussed in Chapter 5 (Mitigation) of the 2018 HSTT FEIS/OEIS, 
existing Navy visual mitigation procedures and measures, when performed 
by individual units at-sea, still remain the most effective and 
practical means of protection for marine species.
    Comment 43: In a comment on the 2018 HSTT proposed rule, Commenters 
stated that NMFS should add mitigation for other marine mammal 
stressors such as dipping sonar, pile driving, and multiple exposures 
near homeports.
    Response: The Navy implements a 200-yd shutdown for dipping sonar 
and a 100-yd exclusion zone for pile-driving. It is unclear what the 
Commenter means by adding mitigation for ``multiple exposures'' near 
homeports, and therefore no explanation can be provided.
Mitigation Areas

Introduction

    The Navy included a comprehensive proposal of mitigation measures 
in their 2017 application that included procedural mitigations that 
reduce the likelihood of mortality, injury, hearing impairment, and 
more severe behavioral responses for most species. The Navy also 
included time/area mitigation that further protects areas where 
important behaviors are conducted and/or sensitive species congregate, 
which reduces the likelihood of takes that are likely to impact 
reproduction or survival (as described in the Mitigation Measures 
section of the final rule and the Navy's application). As a general 
matter, where an applicant proposes measures that are likely to reduce 
impacts to marine 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). However, it is 
necessary for NMFS to consider whether there are additional practicable 
measures that could also contribute to effecting the least practicable 
adverse impact on the species or stocks and their habitat. In the case 
of the Navy's HSTT application, we worked with the Navy prior to the 
publication of the 2018 HSTT proposed rule and ultimately the Navy 
agreed to increase geographic mitigation areas adjacent to the island 
of Hawaii to more fully encompass specific biologically important areas 
and the Alenuihaha Channel and to limit additional anti-submarine 
warfare mid-frequency active sonar (ASW) source bins (MF4) within some 
geographic mitigation areas.
    During the public comment period on the 2018 HSTT proposed rule, 
NMFS received numerous recommendations for the Navy to implement 
additional mitigation measures, both procedural and time/area 
limitations. Extensive discussion of the recommended mitigation 
measures in the context of the factors considered in the least 
practicable adverse impact analysis (considered in the Mitigation 
Measures section of the final rule and described below), as well as 
considerations of alternate iterations or portions of the recommended 
measures considered to better address practicability concerns, resulted 
in the addition of several procedural mitigations and expansion of 
multiple time/area mitigations (see the Mitigation Measures section in 
the final rule). These additional areas reflect, for example, concerns 
about blue whales in SOCAL and small resident odontocete populations in 
Hawaii (which resulted in expanded time/area mitigation), focus on 
areas where important behaviors and habitat are found (e.g., in BIAs), 
and enhancement of the Navy's ability to detect and reduce injury and 
mortality (which resulted in expanded monitoring before and after 
explosive events). Through extensive discussion, NMFS and the Navy 
worked to identify and prioritize additional mitigation measures that 
are likely to reduce impacts on marine mammal species or stocks and 
their habitat and are also possible for the Navy to implement.
    Following the publication of the 2013 HSTT MMPA incidental take 
rule, the Navy and NMFS were sued and the resulting settlement 
agreement prohibited or restricted Navy activities within specific 
areas in the HSTT Study Area. These provisional prohibitions and 
restrictions on activities within the HSTT Study Area were derived 
pursuant to negotiations with the plaintiffs in that lawsuit and were 
specifically not evaluated or selected based on the type of thorough 
examination of best available science that occurs through the 
rulemaking process under the MMPA, or through related analyses 
conducted under the National Environmental Policy Act (NEPA) or the 
ESA. The agreement did not constitute a concession by the Navy as to 
the potential impacts of Navy activities on marine mammals or any other 
marine species, or to the practicability of the measures. The Navy's 
adoption of restrictions on its HSTT activities as part of a relatively 
short-term settlement did not mean that those restrictions were 
necessarily supported by the best available science, likely to reduce 
impacts to marine mammal species or stocks and their habitat, or 
practicable to implement from a military readiness standpoint over the 
longer term in the HSTT Study Area. Accordingly, as required by 
statute, NMFS analyzed the Navy's activities, impacts, mitigation and 
potential mitigation (including the settlement agreement measures) 
pursuant to the least practicable adverse impact standard to determine 
the appropriate mitigation to include in these regulations. Some of the 
measures included in the settlement agreement are included in the final 
rule, while some are not. Other measures that were not included in the 
settlement agreement are included in the final rule.
    Ultimately, the Navy adopted all mitigation measures that are 
practicable without jeopardizing its mission and Title 10 
responsibilities. In other words, a comprehensive assessment by Navy 
leadership of the final, entire list of mitigation measures concluded 
that the inclusion of any further mitigation beyond those measures 
identified here in the final rule would be impracticable. NMFS 
independently reviewed the Navy's practicability determinations for 
specific mitigation areas and concurs with the Navy's analysis.
    As we outlined in the Mitigation Measures section of the 2018 HSTT 
final rule, NMFS reviewed Appendix K (Geographic Mitigation Assessment) 
in the 2018 HSTT FEIS/OEIS and the information contained there reflects 
the best available science as well as a robust evaluation of the 
practicability of different measures. NMFS used Appendix K to support 
our independent

[[Page 41816]]

least practicable adverse impact analysis. Below is additional 
discussion regarding specific recommendations for mitigation measures.
    Comment 44: With respect to the national security exemption related 
to mitigation areas, in a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that NMFS should specify that authorization may 
be given only by high-level officers, consistent with the Settlement 
Agreement or with previous HSTT rulings.
    Response: The Navy provided the technical analyses contained in 
Appendix K (Geographic Mitigation Assessment) of the 2018 HSTT FEIS/
OEIS that included details regarding changing the measure to the 
appropriate delegated Command designee (see specifically Appendix K, 
Section K.2.2.1 (Proposed Mitigation Areas within the HSTT Study Area), 
for each of the proposed areas). The Commenter proposed ``authorization 
may be given only by high-level officers'' and therefore appears to 
have missed the designations made within the cited sections since those 
do constitute positions that could only be considered ``high level 
officers.'' The decision would be delegated to high-level officers. 
This delegation has been clarified in this rule as ``permission from 
the appropriate designated Command authority.''

SOCAL Areas

    Comment 45: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that the Navy consider units of the National Park 
Service (NPS) system and similar areas that occur near the Navy's 
training and testing locations in Southern California and which may be 
affected by noise, including Channel Islands National Park and Cabrillo 
National Monument, as it plans its activities in the HSTT Study Area.
    Response: Both NMFS and the Navy did consider the effects of Navy 
activities on NPS sites and National Monuments. National Parks (NP) and 
National Monuments are addressed in Chapter 6 of the 2018 HSTT FEIS/
OEIS. The Channel Islands NP consists of the five islands and 
surrounding ocean environment out to 1 nmi of Anacapa Island, Santa 
Cruz Island, Santa Rosa Island, San Miguel Island, and Santa Barbara 
Island. Similarly, the Channel Islands National Marine Sanctuary (NMS) 
consists of the ocean waters within an area of 1,109 nmi\2\ that also 
surround the same islands of Anacapa Island, Santa Cruz Island, Santa 
Rosa Island, San Miguel Island and Santa Barbara Island to the south. 
The Channel Islands NMS waters extend from mean high tide to 6 nmi 
offshore around each of these five islands which would also encompass 
the surrounding ocean waters of the Channel Islands NP. Only 92 nmi\2\ 
of Santa Barbara Island, or about 8 percent of the Channel Islands NMS, 
occurs within the SOCAL portion of the HSTT Study Area, but the 
entirety of that piece is included in the Santa Barbara Mitigation 
Area. The Navy will continue to implement a mitigation area out to 6 
nmi of Santa Barbara Island, which includes a portion of the Channel 
Islands NMS (inclusive of the Channels Island NP portion) where the 
Navy will restrict the use of MF1 sonar sources and some explosives 
during training. Therefore, no impacts are expected to occur within the 
waters of the Channel Islands NP. Please refer to Figure 5.4-4 in the 
2018 HSTT FEIS/OEIS, which shows the spatial extent of the Santa 
Barbara Island Mitigation Area. Cabrillo National Monument in San Diego 
only contains some intertidal areas, but no marine waters. No Navy 
activities overlap with the Cabrillo National Monument; therefore, no 
impacts are expected.
    Comment 46: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended to extend the seasonality of the San Diego Arc 
Mitigation Area to December 31 for blue whales that are present off 
southern California almost year round, and relatively higher levels 
from June 1 through December 31.
    Response: Analysis of the San Diego Arc Mitigation Area and its 
consideration for additional geographic mitigation is provided in the 
2018 HSTT FEIS/OEIS in Appendix K (Geographic Mitigation Assessment), 
Section K.4.1.6 (San Diego (Arc) Blue Whale Feeding Area; Settlement 
Areas 3-A through 3-C, California Coastal Commission 3 nmi Shore Area, 
and San Diego Arc Area), Section K.5.5 (Settlement Areas within the 
Southern California Portion of the HSTT Study Area), and Section K.6.2 
(San Diego Arc: Area Parallel to the Coastline from the Gulf of 
California Border to just North of Del Mar). This analysis included 
consideration of seasonality and the potential effectiveness of 
restrictions to use of MFAS by the Navy in the area. Based on further 
discussion between NMFS and the Navy in consideration of the Appendix K 
(Geographic Mitigation Assessment) analyses, with the 2018 HSTT final 
rule the Navy implemented additional mitigation within the San Diego 
Arc Mitigation Area, as detailed in this 2020 rule and Chapter 5 
(Mitigation) Section 5.4.3 (Mitigation Areas for Marine Mammals in the 
Southern California Portion of the Study Area) of the 2018 HSTT FEIS/
OEIS, to further avoid or reduce impacts on marine mammals from 
acoustic and explosive stressors and vessel strikes from Navy training 
and testing in this location. The Navy is limiting MF1 surface ship 
hull-mounted MFAS even further in the San Diego Arc Mitigation Area. 
The Navy will not conduct more than 200 hrs of MF1 MFAS in the combined 
areas of the San Diego Arc Mitigation Area and newly added San Nicolas 
Island and Santa Monica/Long Beach Mitigation Areas. As described in 
the 2018 rule and this rule, the Navy will not use explosives that 
could potentially result in the take of marine mammals during large-
caliber gunnery, torpedo, bombing, and missile (including 2.75-in 
rockets) activities during training and testing in the San Diego 
Mitigation Area. Regarding the recommended increase in seasonality to 
December 31, the San Diego Arc current seasonality is based on the 
Biologically Important Area associated with this mitigation area 
(Calambokidis et al., 2015), which identifies the primary months for 
feeding. While blue whale calls have been detected in Southern 
California through December (Rice et al., 2017, Lewis and 
[Scaron]irovi[cacute], 2018), given a large propagation range (10-50 km 
or more) for low-frequency blue whale vocalization, blue whale call 
detection from a Navy-funded single passive acoustic device near the 
San Diego Arc may not be a direct correlation with blue whale presence 
within the San Diego Arc from November through December. In addition, 
passive acoustic call detection data does not currently allow for 
direct abundance estimates. Calls may indicate some level of blue whale 
presence, but not abundance or individual residency time. In the most 
recent Navy-funded passive acoustic monitoring report including the one 
site in the northern San Diego Arc from June 2015 to April 2016, blue 
whale call detection frequency near the San Diego Arc started declining 
in November after an October peak (Rice et al., 2017, 
[Scaron]irovi[cacute], personal communication). The Navy-funded 
research on blue whale movements from 2014 to 2017 along the U.S. West 
Coast based on satellite tagging, has shown that individual blue whale 
movement is wide ranging with large distances covered daily (Mate et 
al., 2017). Nineteen (19) blue whales were tagged in 2016, the most 
recent reporting year available (Mate et al., 2017). Only 5 of the 19 
blue whales spent time in the SOCAL portion of the HSTT Study Area, and 
only spent a few days within the range complex (2-13 days). Average 
distance from shore for

[[Page 41817]]

blue whales was 113 km. None of the 19 blue whales tagged in 2016 spent 
time within the San Diego Arc. From previous year efforts (2014-2015), 
only a few tagged blue whales passed through the San Diego Arc. In 
addition, Navy and non-Navy-funded blue whale satellite tagging studies 
started in the early 1990s and have continued irregularly through 2017. 
In general, most blue whales start a south-bound migration from the 
``summer foraging areas'' in the mid- to late-fall time period, unless 
food has not been plentiful, which can lead to a much earlier migration 
south. Therefore, while blue whales have been documented within the San 
Diego Arc previously, individual use of the area is variable, likely of 
short duration, and declining after October. Considering the newest 
passive acoustic and satellite tagging data, there is no scientific 
justification for extending the San Diego Arc Mitigation Area period 
from October 31 to December 31.
    Comment 47: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended limiting all MF1 use within the San Diego Arc 
Mitigation Area. A Commenter also recommended NMFS should carefully 
consider prohibiting use of other LFAS and MFAS during the time period 
the San Diego Arc Mitigation Area is in place, and for the MTEs to be 
planned for other months of the year.
    Response: Based on further discussion between NMFS and the Navy in 
consideration of the proposed mitigation presented in the 2018 HSTT 
proposed rule, the Navy is now limiting MF1 surface ship hull-mounted 
MFAS even further in the San Diego Arc Mitigation Area. The Navy will 
not conduct more than 200 hrs of MF1 MFAS in the combined areas of the 
San Diego Arc Mitigation Area and newly added San Nicolas Island and 
Santa Monica/Long Beach Mitigation Areas. The Mitigation Measures 
section of the 2018 HSTT final rule and Appendix K (Geographic 
Mitigation Assessment) of the 2018 HSTT FEIS/OEIS discuss MFAS 
restrictions within the San Diego Arc Mitigation Area. Other training 
MFAS systems are likely to be used less frequently in the vicinity of 
the San Diego Arc area than surface ship MFAS. Given water depths, the 
San Diego Arc area is not conducive for large scale anti-submarine 
warfare exercises, nor is it near areas where other anti-submarine 
warfare training and testing occurs. Due to the presence of existing 
Navy subareas in the southern part of the San Diego Arc, a limited 
amount of helicopter dipping MFAS could occur. These designated range 
areas are required for proximity to airfields in San Diego such as 
Naval Air Station North Island and for airspace management. However, 
helicopters only use these areas in the Arc for a Kilo Dip. A Kilo Dip 
is a functional check of approximately 1-2 pings of active sonar to 
confirm the system is operational before the helicopter heads to more 
remote offshore training areas. This ensures proper system operation 
and avoids loss of limited training time, expenditure of fuel, and 
cumulative engine use in the event of equipment malfunction. The 
potential effects of dipping sonar have been accounted for in the 
rule's analysis. Dipping sonar is further discussed below in Comment 
48.
    Comment 48: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended prohibiting the use of air-deployed MFAS in the 
San Diego Arc Mitigation Area.
    Response: The 2018 HSTT FEIS/OEIS and specifically Appendix K 
(Geographic Mitigation Assessment) analyze MFAS and LFAS restrictions 
within the San Diego Arc. Other sonar systems are used less frequently 
in the vicinity of the San Diego Arc than surface ship MFAS. In regard 
to the recommendation to prohibit ``air-deployed'' or dipping MFAS, the 
only helicopter dipping sonar activity that would likely be conducted 
in the San Diego Arc area is a Kilo Dip, which occurs relatively 
infrequently and involves a functional check of approximately 1-2 pings 
of active sonar before moving offshore beyond the San Diego Arc to 
conduct the training activity. During use of this sonar, the Navy will 
implement the procedural mitigation described in the Mitigation 
Measures section of this rule. The Kilo Dip functional check needs to 
occur close to Naval Air Station North Island in San Diego to ensure 
all systems are functioning properly, before moving offshore. This 
ensures proper system operation and avoids loss of limited training 
time, expenditure of fuel, and cumulative engine use in the event of 
equipment malfunction. The potential effects of dipping sonar have been 
accounted for in the rule's analysis. Further, due to lower power 
settings for dipping sonar, potential behavioral impact ranges of 
dipping sonar are significantly lower than surface ship sonars. For 
example, the HSTT average modeled range to temporary threshold shift of 
dipping sonar for a 1-second ping on low-frequency cetacean (i.e., blue 
whale) is 77 m (2018 HSTT FEIS/OEIS Table 3.7-7). This range is easily 
monitored for large whales by a hovering helicopter and is accounted 
for in the mitigation ranges for dipping sonars. Limited ping time and 
lower power settings therefore would limit the impact from dipping 
sonar to any marine mammal species. It should be pointed out that the 
Commenter's recommendation is based on new behavioral response research 
specific to beaked whales (Falcone et al., 2017). The Navy relied upon 
the best science that was available to develop behavioral response 
functions in consultation with NMFS for the 2018 HSTT FEIS/OEIS. The 
article cited in the comment (Falcone et al., 2017) was not available 
at the time the 2017 HSTT DEIS/OEIS was published. NMFS and the Navy 
have reviewed the article and concur that neither this article nor any 
other new information that has been published or otherwise conveyed 
since the 2018 HSTT proposed rule was published would fundamentally 
change the assessment of impacts or conclusions in the 2018 HSTT FEIS/
OEIS or in this rulemaking. Nonetheless, the new information and data 
presented in the new 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. The 
new information and data presented in the article was thoroughly 
reviewed when it became available and further considered in discussions 
with some of the paper's authors. Many of the variables requiring 
further analysis for beaked whales and dipping sonar impact assessment 
are still being researched under continued Navy funding through 2023. 
The small portion of designated Kilo Dip areas that overlap the 
southern part of the San Diego Arc is not of sufficient depth for 
preferred habitat of beaked whales (see Figure 2.1-9 in the 2018 HSTT 
FEIS/OEIS). Further, passive acoustic monitoring for the past several 
years in the San Diego Arc confirms a lack of beaked whale detections 
(Rice et al., 2017). Also, behavioral responses of beaked whales from 
dipping and other sonars cannot be universally applied to other species 
including blue whales. Navy-funded behavioral response studies of blue 
whales to simulated surface ship sonar has demonstrated there are 
distinct individual variations as well as strong behavioral state 
considerations that influence any response or lack of response 
(Goldbogen et al., 2013).
    Comment 49: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended requiring vessel speed

[[Page 41818]]

restrictions within the San Diego Arc Mitigation Area.
    Response: Previously, the Navy commissioned a vessel density and 
speed report for the HSTT Study Area (CNA, 2016). Based on an analysis 
of Navy ship traffic in the HSTT Study Area between 2011 and 2015, 
median speed of all Navy vessels within Southern California is 
typically already low, with median speeds between 5 and 12 kn (CNA, 
2016). Slowest speeds occurred closer to the coast including the 
general area of the San Diego Arc and approaches to San Diego Bay. The 
presence and transits of commercial and recreational vessels, numbering 
in the many hundreds, far outweighs the presence of Navy vessels. 
Regarding strikes by vessels other than Navy vessels, two blue whale 
ship strike deaths were observed during the most recent five-year 
period of 2013-2017 (Carretta et al. 2019, final 2018 SARs). There were 
no reported ship-strike related serious injuries during this time 
period (Carretta et al. 2019). Observations of blue whale ship strikes 
have been highly-variable in previous five-year periods, with as many 
as 10 observed (nine deaths and one serious injury) during 2007-2011 
(Carretta et al., 2013). The highest number of blue whale ship strikes 
observed in a single year (2007) was five whales (Carretta et al. 
2013). Additionally, ship strike mortality was estimated for blue 
whales in the U.S. West Coast EEZ (Rockwood et al., 2017), using an 
encounter theory model (Martin et al., 2016) that combined species 
distribution models of whale density (Becker et al., 2016), vessel 
traffic characteristics (size, speed, and spatial use), along with 
whale movement patterns obtained from satellite-tagged whales in the 
region to estimate encounters that would result in mortality and 
predicted higher annual numbers of mortality. But as discussed in this 
final rule, the SAR further cites to Monnahan et al. (2015), which used 
a population dynamics model to estimate that the Eastern North Pacific 
blue whale population was at 97 percent of carrying capacity in 2013 
and to suggest that the observed lack of a population increase since 
the early 1990s was explained by density dependence, not impacts from 
ship strike. Ship strike in the West Coast EEZ continues to be complex 
with vessel speeds, types, and routes of travel all contributing to 
variability in ship traffic and animal vulnerability. That said, there 
has been no confirmed Navy ship strike to a blue whale in the entire 
Pacific over the 14-year period from 2005 to 2019. To minimize the 
possibility of ship strike in the San Diego Arc Mitigation Area, the 
Navy will implement procedural mitigation for vessel movements based on 
guidance from NMFS for vessel strike avoidance. The Navy will also 
issue seasonal awareness notification messages to all Navy vessels of 
blue, fin, and gray whale occurrence to increase ships awareness of 
marine mammal presence as a means of improving detection and avoidance 
of whales in SOCAL. When developing the mitigation for the 2018 HSTT 
final rule, NMFS and the Navy analyzed the potential for implementing 
additional types of mitigation, such as developing vessel speed 
restrictions within the HSTT Study Area. The Navy determined that based 
on how the training and testing activities will be conducted within the 
HSTT Study Area under the planned activities, vessel speed restrictions 
would be incompatible with the practicability assessment criteria for 
safety, sustainability, and Title 10 requirements, as described in 
Section 5.3.4.1 (Vessel Movement) of the 2018 HSTT FEIS/OEIS.
    Comment 50: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended prohibiting the use of air-deployed MFAS in the 
Santa Barbara Island Mitigation Area.
    Response: The Commenter's request to prohibit ``air-deployed'' MFAS 
is based on one paper (Falcone et al., 2017), which is a Navy-funded 
project designed to study behavioral responses of a single species, 
Cuvier's beaked whales, to MFAS. The Navy in consultation with NMFS 
relied upon the best science that was available to develop behavioral 
response functions for beaked whales and other marine mammals for the 
2018 HSTT FEIS/OEIS. NMFS and the Navy have reviewed the article and 
concur that neither this article (Falcone et al., 2017) nor any other 
new information that has been published or otherwise conveyed since the 
2018 HSTT proposed rule was published would fundamentally change the 
assessment of impacts or conclusions in the 2018 HSTT FEIS/OEIS or in 
this rulemaking. Nonetheless, the new information and data presented in 
the new 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. Many of the 
variables requiring further analysis for beaked whales and dipping 
sonar impact assessment are still being researched under continued Navy 
funding through 2023.
    Behavioral responses of beaked whales from dipping and other sonars 
cannot be universally applied to other marine mammal species. For 
example, Navy-funded behavioral response studies of blue whales to 
simulated surface ship sonar has demonstrated there are distinct 
individual variations as well as strong behavioral state considerations 
that influence any response or lack of response (Goldbogen et al., 
2013). The same conclusion on the importance of exposure and behavioral 
context was stressed by Harris et al. (2017). Therefore, it is expected 
that other species would also have highly variable individual responses 
ranging from some response to no response to any anthropogenic sound. 
This variability is accounted for in the current behavioral response 
curves described in the 2018 HSTT FEIS/OEIS and supporting technical 
reports, and used by NMFS in the MMPA rule.
    The potential effects of dipping sonar have been rigorously 
accounted for in the analysis. Parameters such as power level and 
propagation range for typical dipping sonar use are factored into HSTT 
acoustic impact analysis along with guild specific criteria and other 
modeling variables as detailed in the 2018 HSTT FEIS/OEIS and 
associated technical reports for criteria and acoustic modeling. Due to 
lower power settings for dipping sonar, potential impact ranges of 
dipping sonar are significantly lower than surface ship sonars. For 
example, the HSTT average modeled range to temporary threshold shift of 
dipping sonar for a 1-second ping on low-frequency cetacean (i.e., blue 
whale) is 77 m, and for mid-frequency cetaceans including beaked whales 
is 22 m (2018 HSTT FEIS/OEIS Table 3.7-7). This range is monitored for 
marine mammals by a hovering helicopter and is accounted for in the 
mitigation ranges for dipping sonars (200 yd or 183 m). Limited ping 
time and lower power settings therefore would limit the impact from 
dipping sonar to any marine mammal species.
    For other marine mammal species, the small area around Santa 
Barbara Island does not have resident marine mammals, identified 
biologically important areas, nor is it identified as a breeding or 
persistent foraging location for cetaceans. Instead, the same marine 
mammals that range throughout the offshore Southern California area 
could pass at some point through the marine waters of Santa Barbara 
Island. As discussed in the mitigation section of the rule, the Navy 
will implement (and is currently implementing) year-round limitations 
to MFAS and larger

[[Page 41819]]

explosive use. The Navy will not use MF1 surface ship hull-mounted MFAS 
during training or testing, or explosives that could potentially result 
in the take of marine mammals during medium-caliber or large-caliber 
gunnery, torpedo, bombing, and missile (including 2.75-in rockets) 
activities during training in the Santa Barbara Island Mitigation Area. 
Other MFAS systems within SOCAL are used less frequently than surface 
ship sonars, and more importantly are of much lower power with 
correspondingly lower propagation ranges and reduced potential 
behavioral impacts.
    Comment 51: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended prohibiting other sources of MFAS in the Santa 
Barbara Mitigation Area.
    Response: Appendix K (Geographic Mitigation Assessment) of the 2018 
HSTT FEIS/OEIS, which NMFS reviewed, concurred with, and used to 
support our MMPA least practicable adverse impact analysis, discusses 
the Navy's analysis of MFAS restrictions around Santa Barbara Island. 
Other training MFAS systems are likely to be used less frequently in 
the vicinity of Santa Barbara Island than surface ship MFASs. Although 
not prohibiting the use of other sources of MFAS, the Navy will not use 
MF1 surface ship hull-mounted MFAS during training or testing, or 
explosives that could potentially result in the take of marine mammals 
during medium-caliber or large-caliber gunnery, torpedo, bombing, and 
missile (including 2.75-in rockets) activities during training in the 
Santa Barbara Island Mitigation Area.
    The relatively small area surrounding the Santa Barbara Island 
Mitigation Area represents less than 0.08 percent of the entire HSTT 
SOCAL area. An even smaller portion of this area meets the 
scientifically accepted minimum depth criteria expected for beaked 
whale habitat, in Southern California usually greater than 800 m. The 
bathymetric area greater than 800 m depth and within the Santa Barbara 
Island Mitigation Area is approximately 24 square Nmi (26 percent of 
the total Mitigation Area spatial extent or only 0.02 percent of the 
total HSTT SOCAL area). Beaked whale monitoring at other locations 
within SOCAL have shown that even in ocean basins thought to have 
Cuvier's beaked whale sub-population, there is still quite a bit of 
variation in occurrence and movement of beaked whales within a given 
basin (Schorr et al., 2017, 2018, 2020). The small area around Santa 
Barbara Island is not known to have resident marine mammals, formally 
identified biologically important areas, nor is it identified as a 
breeding or persistent foraging location for cetaceans. Instead, the 
same marine mammals that range throughout the offshore Southern 
California area could pass at some point through the marine waters of 
Santa Barbara Island. As discussed in this rule the Navy is 
implementing year-round limitations to MFAS and larger explosive use. 
Other MFAS systems for which the Navy sought coverage within SOCAL are 
used less frequently than surface ship sonars, and more importantly are 
of much lower power with correspondingly lower propagation ranges and 
reduced potential behavioral impacts. Therefore, further limitations of 
active sonars within this area are not anticipated to be meaningfully 
more protective to marine mammal populations than existing mitigation 
measures within the entire SOCAL portion of the HSTT Study Area.
    Comment 52: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended implementing vessel speed restrictions in the 
Santa Barbara Island Mitigation Area (Channel Islands Sanctuary 
Cautionary Area).
    Response: The Channel Islands Sanctuary Cautionary Area was renamed 
the Santa Barbara Island Mitigation Area for the rule. All locations 
within the HSTT Study Area have been used for Navy training and testing 
for decades. There has not been any Navy ship strike to marine mammals 
in SOCAL over the 10-year period from 2010-2019, and there has never 
been a Navy strike within the boundary of the Channel Islands National 
Marine Sanctuary over the course of strike record collection dating 
back 20 years. Therefore, ship strike risk to marine mammals transiting 
the Santa Barbara Island Mitigation Area is minimal. Additionally, as 
discussed in this rule, the 2018 HSTT final rule, and the 2018 HSTT 
FEIS/OEIS Section 3.7.3.4.1 (Impacts from Vessels and In-Water Devices) 
and Appendix K (Geographic Mitigation Assessment), there are important 
differences between most Navy vessels and their operation and 
commercial ships that individually make Navy vessels much less likely 
to strike a whale. Navy vessels already operate at lower speeds given a 
particular transit or activity need. Mitigation measures include a 
provision to avoid large whales by 500 yd, so long as safety of 
navigation and safety of operations is maintained. Previously, the Navy 
commissioned a vessel density and speed report for HSTT (CNA, 2016). 
Based on an analysis of Navy ship traffic in HSTT between 2011 and 
2015, the average speed of all Navy vessels within Southern California 
is typically already low, with median speeds between 5 and 12 kn (CNA, 
2016). Slowest speeds occurred closer to the coast and islands. Given 
the history of no documented Navy ship strikes over the last 10 years 
(2010-2019) throughout SOCAL during Navy activities, lack of 
significant and repeated use of the small portion of waters within the 
Santa Barbara Island Mitigation Area by marine mammals, anticipated low 
individual residency times within the Santa Barbara Island Mitigation 
Area, application of mitigation and protective measures as outlined in 
this rule and the 2018 HSTT final rule, documented lower speeds Navy 
vessels already navigate by, detailed assessments of realistic training 
and testing requirements, and potential impacts of further 
restrictions, NMFS has determined that vessel speed restrictions in the 
Santa Barbara Island Mitigation Area are not warranted.
    Comment 53: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended additional mitigation areas for important beaked 
whale habitat in the Southern California Bight. The Commenter asserted 
that it is important to focus substantial management efforts on beaked 
whales within the Navy's SOCAL Range Complex, which sees the greatest 
annual amount of sonar and explosives activity of any Navy range in the 
Pacific.
    Response: The basis for this comment includes incorrect or outdated 
information or information that does not reflect the environment 
present in the HSTT Study Area, such as, ``. . . beaked whale 
populations in the California Current have shown significant, possibly 
drastic declines in abundance over the last twenty years.'' The 
citation provided in the footnote to the comment and postulated 
``decline'' was for beaked whales up until 2008 (which does not take 
into account information from the last 10 years) and was a postulated 
trend for the entire U.S. West Coast, not data which is specific to the 
HSTT Study Area. As noted in Section 3.7.3.1.1.7 (Long-Term 
Consequences) of the 2018 HSTT FEIS/OEIS, the postulated decline was in 
fact not present within the SOCAL portion of the HSTT Study Area, where 
abundances of beaked whales have remained higher than other locations 
off the U.S. West Coast. In addition, the authors of the 2013 citation 
(Moore and Barlow, 2013) have published trends based on survey data 
gathered since 2008 for beaked whales in the California Current, which 
now includes the highest abundance estimate in the history of these 
surveys (Barlow 2016; Carretta et al., 2017; Moore and Barlow,

[[Page 41820]]

2017). Also, 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 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. NMFS and the Navy considered additional 
geographic mitigation for beaked whales in the Southern California 
Bight, as described in Appendix K (Geographic Mitigation Assessment), 
Section K.7.2 (Southern California Public Comment Mitigation Area 
Assessment) and specifically Section K.7.2.7 (Northern Catalina Basin 
and the San Clemente Basin) of the 2018 HSTT FEIS/OEIS, which NMFS used 
in support of this rule. See Chapter 5 (Mitigation), Section 5.4.1.2 
(Mitigation Area Assessment) of the 2018 HSTT FEIS/OEIS for additional 
details regarding the assessments of areas considered for mitigation.
    Comment 54: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended additional mitigation areas in the San Nicolas 
Basin. The Commenter noted that the settlement agreement established a 
``refuge'' from sonar and explosives activities in a portion of the 
whales' secondary habitat, outside the Southern California Anti-
submarine Warfare Range (SOAR), with more management effort being 
necessary in the long term. The Commenter recommended at a minimum that 
NMFS should prescribe the ``refuge'' during the next five-year 
operation period and should consider all possible habitat-based 
management efforts, including but not limited to the expansion of this 
area further south towards SOAR, to address impacts on the small 
population of Cuvier's beaked whales associated with San Clemente 
Island.
    Response: NMFS and the Navy considered additional geographic 
mitigation for beaked whales in the San Nicolas Basin, as described in 
Appendix K (Geographic Mitigation Assessment), Section K.7.2 (Southern 
California Public Comment Mitigation Area Assessment), and specifically 
Section K.7.2.1 (San Nicolas Basin) of the 2018 HSTT FEIS/OEIS, which 
NMFS reviewed, concurred with, and used to support the mitigation 
analysis in the rule. See Chapter 5 (Mitigation), Section 5.4.1.2 
(Mitigation Area Assessment) of the 2018 HSTT FEIS/OEIS for additional 
details regarding the assessments of areas considered for mitigation. 
Further, the Mitigation Measures, Brief Comparison of 2015 Settlement 
Mitigation and Final HSTT Mitigation in the Rule section of the 2018 
HSTT final rule explicitly discusses NMFS consideration of mitigation 
that was included in the settlement agreement versus what was included 
in the final rule in the context of the MMPA least practicable adverse 
impact standard.
    Within the San Nicolas Basin, there is a documented, recurring 
number of Cuvier's beaked whales strongly indicating that the Navy's 
activities are not having a population-level impact on this species. 
This is supported by repeated visual re-sighting rates of individuals, 
sightings of calves and, more importantly, reproductive females, and 
passive acoustic assessments of steady vocalization rates and abundance 
over at least the most recent seven-year interval. It is incorrect to 
conclude that there is a ``population sink,'' such as has been seen on 
the Navy's AUTEC range. In the citation provided (Claridge, 2013), that 
statement is merely a hypothesis, yet to be demonstrated.
    The Navy has been funding Cuvier's beaked whale research 
specifically in the San Nicolas Basin since 2006. This research is 
planned to continue through the duration of this MMPA authorization. 
Cumulative from 2006 to 2016, over 170 individual Cuvier's beaked 
whales have been catalogued within the San Nicolas Basin. Schorr et al. 
(2018) stated for the field season from 2016 to 2017 that: 
Identification photos of suitable quality were collected from 69 of the 
estimated 81 individual Cuvier's beaked whales encountered in 2016-
2017. These represented 48 unique individuals, with eight of these 
whales sighted on two different days, and another three on three 
different days during the study period. Nineteen (39 percent) of these 
whales had been sighted in previous years. Many more whales identified 
in 2016 had been sighted in a previous year (16/28 individuals, 57 
percent), compared to 2017 (5/22 individuals, 23 percent), though both 
years had sightings of whales seen as early as 2007. There were three 
adult females photographed in 2016 that had been sighted with calves in 
previous years, one of which was associated with her second calf. 
Additionally, a fourth adult female, first identified in 2015 without a 
calf, was subsequently sighted with a calf. The latter whale was 
sighted for a third consecutive year in 2017, this time without a calf, 
along with two other adult females with calves who had not been 
previously sighted. These sightings of known reproductive females with 
and without calves over time (n = 45) are providing critically needed 
calving and weaning rate data for Population Consequences of 
Disturbance (PcoD) models currently being developed for this species on 
SOAR.
    From August 2010 through October 2019, an estimate of overall 
abundance of Cuvier's beaked whales at the Navy's instrumented range in 
San Nicolas Basin was obtained using new dive-counting acoustic methods 
and an archive of passive acoustic M3R data representing 49,855 hours 
of data (DiMarzio et al., 2020). Over the 10-year interval from 2010-
2019, there was no observed change and perhaps a slight increase in 
annual Cuvier's beaked whale abundance within San Nicolas Basin 
(DiMarzio et al., 2020). There does appear to be a repeated dip in 
population numbers and associated echolocation clicks during the fall 
centered around August and September (DiMarzio et al., 2020; Moretti, 
2017). A similar August and September dip was noted by researchers 
using stand-alone off-range bottom passive acoustic devices in Southern 
California (Rice et al., 2017, 2019, 2020; [Scaron]irovi[cacute] et 
al., 2016). This dip in abundance documented over 10 years of 
monitoring may be tied to some as of yet unknown population dynamic or 
oceanographic and prey availability dynamic. It is unknown 
scientifically if this represents a movement to different areas by 
parts of the population, or a change in behavioral states without 
movement (i.e., breeding versus foraging). Navy training and testing 
events are spatially and temporally spread out across the SOCAL portion 
of the HSTT Study Area. In some years events occur in the fall, yet in 
other years events do not. Yet, the same dip has consistently been 
observed lending further evidence this is likely a population 
biological function.
    Comment 55: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended additional mitigation areas in the Santa Catalina 
Basin. A Commenter commented that there is likely a small, resident 
population of Cuvier's beaked whales that resides in the Santa Catalina 
Basin and that this population is subject to regular acoustic 
disturbance due to the presence of the Shore Bombardment Area (SHOBA) 
and 3803XX. The population may also be exposed to training activities 
that

[[Page 41821]]

occupy waters between Santa Catalina and San Clemente Islands. Similar 
to the San Nicolas population, the settlement agreement established a 
``refuge'' from sonar and explosives activities in the northern portion 
of the Santa Catalina Basin. A Commenter recommended that, at a 
minimum, the Navy should carefully consider implementing the ``refuge'' 
during the next five-year authorization period and should continue to 
consider all possible habitat-based management efforts to address 
impacts on the population.
    Response: The water space areas mentioned in the comment as 
``(SHOBA)'' off the southern end of San Clemente Island are waters 
designated as Federal Danger and Safety Zones via formal rulemaking 
(Danger Zone--33 CFR 334.950 and Safety Zone--33 CFR 165.1141) because 
they are adjacent to the shore bombardment impact area that is on land 
at the southern end of San Clemente Island. Waters designated as 
``3803XX,'' which are associated with the Wilson Cove anchorages and 
moorings, where ship calibration tests, sonobuoy lot testing, and 
special projects take place, are designated as Federal Safety and 
Restricted Zones via formal rulemaking (Safety Zone--33 CFR 165.1141 
and Restricted Zone--33 CFR 334.920).
    The comment states a concern that a population of Cuvier's beaked 
whale is, ``subject to regular acoustic disturbance due to the presence 
of the Shore Bombardment Area,'' is not correct. The SHOBA is a naval 
gun impact area located on land at the southern end of San Clemente 
Island. This area is an instrumented land training range used for a 
variety of bombardment training and testing activities. The in-water 
administrative boundary for SHOBA does not delineate the locations 
where a ship firing at land targets must be located and does not 
represent where gunfire rounds are targeted. The water area in Santa 
Catalina Basin is a controlled safety zone in the very unlikely event a 
round goes over the island and lands in the water. With the modern 
advent of better precision munitions, computers, and advanced fire 
control, that probability is very remote. Navy vessels use the waters 
south of San Clemente Island (SHOBA West and SHOBA East) from which to 
fire into land targets on southern San Clemente Island (see the 2018 
HSTT FEIS/OEIS Figure 2.1-7). Therefore, there would not be any 
underwater acoustic disturbance to Cuvier's beaked whales located 
within the Santa Catalina Basin from in-water explosives or ship 
firing. Further, the Mitigation Measures subsection, Brief Comparison 
of 2015 Settlement Mitigation and Final HSTT Mitigation in the Rule 
section, of the 2018 HSTT final rule explicitly discusses NMFS' 
consideration of mitigation that was included in the settlement 
agreement versus what was included in the final rule in the context of 
the MMPA least practicable adverse impact standard.
    Comment 56: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended additional mitigation areas for the southernmost 
edge of the California Current, west of Tanner and Cortes Banks. In 
light of the importance of the Southernmost edge of the California 
Current, west of Tanner and Cortes banks, Commenters recommend 
assessing the designation of the southern offshore waters of the 
Southern California Bight as a seasonal time-area management area for 
Cuvier's beaked whales between November and June. The approximate 
coordinates are 32.75 N., 119.46 W (referenced as Site E). As part of 
this assessment, the Commenter recommended that the boundaries be 
refined via expert consideration of acoustic and other relevant 
information pertaining to beaked whale biology and bathymetric and 
oceanographic data.
    Response: Baumann-Pickering et al. (2014a, b, 2015), as the 
Commenter referenced, did not specify this area as biologically 
important and the author's data only indicated there have been 
detections of the Cuvier's beaked whales within this area. Further, the 
species is widely distributed within Southern California and across the 
Pacific with almost all suitable deep water habitat greater than 800 m 
in Southern California conceivably containing Cuvier's beaked whales. 
Only limited population vital rates exist for beaked whales, covering 
numbers of animals, populations vs. subpopulations determination, and 
residency time for individual animals (Schorr et al., 2017, 2018). The 
science of passive acoustic monitoring is positioned to answer some 
questions on occurrence and seasonality of beaked whales, but cannot as 
of yet address all fundamental population parameters including 
individual residency time.
    Furthermore, while passive acoustic monitoring within Southern 
California has been ongoing for 28 years, with many sites funded by the 
Navy, not all sites have been consecutively monitored for each year. 
All of the single bottom-mounted passive acoustic devices used for the 
analysis by Baumann-Pickering et al. (2014a, b, 2015), and used in the 
comment to support its argument, are not continuous and have various 
periodicities from which data have been collected. Specifically, 
devices have been deployed and removed from various locations with some 
sites having multiple years of data, and others significantly less, 
with perhaps just a few months out of a year. For instance, Site E, 
located west of Tanner and Cortes Banks and used by the Commenter to 
justify restrictions in this area, was only monitored for 322 days from 
September 2006 through July 2009 (obtaining slightly less than a full 
year's worth of data).
    Site E was also used again for another 63 days from Dec 2010 
through February 2011. During this second monitoring period at Site E, 
Gassman et al. (2015) reported detection of only three Cuvier's beaked 
whales over six separate encounters with time intervals of 10-33 
minutes. As sources of data associated with a single monitoring point, 
the two monitoring episodes conducted at Site E may not be indicative 
of Cuvier's beaked whale presence at other locations within Southern 
California, which lack comparable monitoring devices. Nor would they be 
indicative of overall importance or lack of importance of the area west 
of Tanner and Cortes Banks. Further, more recent acoustic sampling of 
bathymetrically featureless areas off Southern California with drifting 
hydrophones conducted by NMFS, detected many beaked whales over abyssal 
plains and not associated with slope or seamount features. This 
counters a common misperception that beaked whales are primarily found 
over slope waters, in deep basins, or over seamounts (Griffins and 
Barlow, 2016).
    Most importantly, older passive acoustic data prior to 2009 may not 
be indicative of current or future occurrence of beaked whales, 
especially in terms of potential impact of climate change on species 
distributions within Southern California. To summarize, these limited 
periods of monitoring (322 days in a three-year period prior to 2010 
and 63 days in 2011) may or may not be reflective of current beaked 
whale distributions within Southern California and into the future. 
Furthermore, passive acoustic-only detection of beaked whales, without 
additional population parameters, can only determine relative 
occurrence, which could be highly variable over sub-regions and through 
time.
    While Cuvier's beaked whales have been detected west of Tanner and 
Cortes Banks, as noted above this species is also detected in most all 
Southern California locations greater than 800 m in depth. Furthermore, 
the Navy has been training and testing in and around Tanner and Cortes 
Banks with the same

[[Page 41822]]

basic systems for over 40 years, with no evidence of any adverse 
impacts having occurred. Further, there are no indications that Navy 
training and testing in the SOCAL portion of the HSTT Study Area has 
had any adverse impacts on populations of beaked whales in Southern 
California. In particular, a reoccurring population of Cuvier's beaked 
whales co-exists within San Nicolas Basin to the east, an area with 
significantly more in-water sonar use than west of Tanner and Cortes 
Banks.
    To gain further knowledge on the presence of beaked whales in 
Southern California, the Navy continues to fund additional passive 
acoustic field monitoring, as well as research advancements for density 
derivation from passive acoustic data. For the five-year period from 
2013 to 2019, U.S. Pacific Fleet on behalf of the U.S. Navy funded $18 
million in marine species monitoring within Hawaii and Southern 
California. Specifically, in terms of beaked whales, the Navy has been 
funding beaked whale population dynamics, tagging, and passive acoustic 
studies within the HSTT Study Area since 2007 (DiMarzio et al., 2018, 
2019, 2020; Moretti, 2017; Rice et al., 2017, 2018, 2019, 2020; Schorr 
et al., 2017, 2018, 2019, 2020; [Scaron]irovi[cacute], et al., 2017). 
Variations of these efforts are planned to continue through the 
duration of the seven-year rule using a variety of passive acoustic, 
visual, tagging, photo ID, and genetics research tools. This Navy 
effort is in addition and complementary to any planned NMFS efforts for 
beaked whales and other marine mammals. For instance, the Navy co-
funded with NMFS and the Bureau of Ocean Energy Management a summer-
fall 2018 visual and passive acoustic survey along the U.S. West Coast 
and off Baja Mexico (Henry et al. in press). New passive detection 
technologies focusing on beaked whales were deployed during these 
surveys (similar to Griffiths and Barlow, 2016). The Navy continues 
SOCAL beaked whale occurrence and impact studies with additional effort 
anticipated through 2020.
    Analysis of the southernmost edge of the California Current, west 
of Tanner-Cortes Bank and the presence of Cuvier's beaked whales was 
addressed in Appendix K (Geographic Mitigation Assessment), Section 
K.7.2.4 (Southernmost Edge of California Current, West of Tanner-Cortes 
Bank), and Section K.7.2.6 (Cuvier's Beaked Whale Habitat Areas 
Mitigation Assessment) of the 2018 HSTT FEIS/OEIS, which NMFS used to 
support its mitigation analysis described in this final rule. Also see 
Chapter 3, Section 3.7.2.3.24 (Cuvier's Beaked Whale (Ziphius 
cavirostris)) of the 2018 HSTT FEIS/OEIS for additional information 
regarding this species.
    As noted in Appendix K (Geographic Mitigation Assessment), the 
waters west of Tanner and Cortes Banks are also critical to the Navy's 
training and testing activities; therefore, it is not practicable to 
preclude activities within that water space in the SOCAL portion of the 
HSTT Study Area. Reasonable mitigation measures, as discussed in 
Appendix K (Geographic Mitigation Assessment), would limit the impact 
of training and testing on marine mammals, and especially beaked 
whales, in this area. In addition, with new deployments of HARP buoys 
from 2019-2021, the Navy has expanded passive acoustic monitoring for 
beaked whales to include new areas west of Tanner Bank and areas off 
Baja Mexico.
    Given that there is no evidence that Navy training and testing 
activities are having significant impacts to populations of beaked 
whales anywhere in the SOCAL portion of the HSTT Study Area, the 
uncertainty of current use by Cuvier's beaked whales of the area west 
of Tanner and Cortes Banks, the fact that general occurrence of beaked 
whales in Southern California may not necessarily equate to factors 
typically associated with biologically important areas, and 
consideration of the importance of Navy training and testing activities 
in the areas around Tanner and Cortes Banks discussed in Appendix K 
(Geographic Mitigation Assessment) of the 2018 HSTT FEIS/OEIS, 
additional geographic mitigation specifically for the area west of 
Tanner and Cortes Banks is not warranted.
    As noted in Appendix K (Geographic Mitigation Assessment) and 
Chapter 5 (Mitigation), Section 5.3 (Procedural Mitigation to be 
Implemented) of the 2018 HSTT FEIS/OEIS, the Navy will continue to 
implement procedural mitigation measures throughout the HSTT Study 
Area.
    Comment 57: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that the same long-term passive acoustic study of the 
Southern California Bight as discussed for Cuvier's beaked whales above 
in Comment 56 also suggests that southern-central waters represent 
biologically important habitat for Perrin's beaked whale. The Commenter 
recommended that the Northern Catalina Basin and the waters southeast 
of Santa Catalina Island (approximate coordinates of 33.28 N, -118.25 
W), and the San Clemente Basin (approximate coordinates of 32.52 N, -
118.32 W), both based on location of HARP deployments (referenced as 
sites ``A'' and ``S''), be considered as management areas for Perrin's 
beaked whales. The Commenter recommended that the boundaries of any 
restrictions be established via expert consideration.
    Response: All of the single bottom-mounted passive acoustic devices 
used for the analysis by Baumann-Pickering et al. (2014b) and used by 
the Commenter to support their argument are not continuous and have 
various periodicities for which data have been collected. As single 
point sources of data, these passive acoustic devices may not be 
indicative of Perrin's beaked whale presence at other locations within 
Southern California without comparable devices. Nor would older data 
prior to 2009 be indicative of current or future occurrence especially 
in terms of potential impact of climate change on species 
distributions.
    Navy-funded passive acoustic monitoring within the SOCAL portion of 
the HSTT Study Area has been ongoing for the past 21 years, but not all 
areas are monitored continuously, and devices have been deployed and 
removed from various locations. Santa Catalina Basin was only monitored 
from August 2005 to July 2009. Santa Catalina Basin has not been 
monitored under Navy funding since 2009 because other areas in Southern 
California were prioritized for passive acoustic device placement by 
the researchers. For San Clemente Island, the single monitoring site 
``S'' used in Baumann-Pickering et al. (2014b) and cited as the source 
of the comment's claim for San Clemente Basin was only deployed for a 
limited time of approximately 1.5 years, resulting in 409 days of data 
(September 2009-May 2011). For both sites combined, only 41 hours of 
BW43 signal types were detected over a cumulative approximately five-
and-a-half years of monitoring. The 41 hours of BW43 detections 
therefore only represents a small fraction of overall recording time 
(less than 1 percent).
    The beaked whale signal type detected called BW43 has been 
suggested as coming from Perrin's beaked whales (Baumann-Pickering et 
al., 2014b), but not yet conclusively and scientifically confirmed.
    A different Navy-funded single site south of San Clemente Island 
within the San Clemente Basin has had a passive acoustic device in 
place from July 2014 through current. [Scaron]irovi[cacute] et al. 
(2016) and Rice et al. (2017) contain the most current results from San 
Clemente Basin site ``N.'' While [Scaron]irovi[cacute] et al. (2016) 
and Rice et al. (2017) do report periodic passive acoustic detections 
of

[[Page 41823]]

Mesoplodon beaked whales thought to be Perrin's beaked whale in San 
Clemente Basin, the overall detection rate, periodicity, and occurrence 
has not been high. Between May 2015 and June 2016, there were only 
seven weeks in which potential Perrin's beaked whale echolocation 
clicks were detected, with each week having less than 0.14 hours/week 
of detections. Acoustic sampling of bathymetrically featureless areas 
off Southern California with drifting hydrophones by NMFS detected many 
beaked whales over abyssal plains and not always associated with slope 
or seamount features, which counters a common misperception that beaked 
whales are primarily found over slope waters, in deep basins, or over 
seamounts (Griffins and Barlow, 2016). One of these devices was 
deployed within the SOCAL portion of the HSTT Study Area. In addition, 
analysis of NMFS visual survey data from 2014, the most recent year 
available, showed an increase in Mesoplodon beaked whales along the 
entire U.S. West Coast, which the authors attributed to an influx of 
tropical species of Mesoplodon during the unusually warm water 
condition that year (Barlow, 2016; Moore and Barlow, 2017). Perrin's 
beaked whale, part of the Mesoplodon guild, could be part of these 
sightings. In summary, San Clemente Basin and Santa Catalina Basin with 
similar low passive acoustic detection rates are likely to be part of 
Perrin beaked whale's general distribution along the U.S. West Coast 
and in particular Southern California and Baja Mexico. This 
distribution is likely to be wide ranging for Perrin's beaked whales as 
a species and highly correlated to annual oceanographic conditions. 
Santa Catalina and San Clemente basins do have infrequent suspected 
Perrin's beaked whale passive acoustic detections from a limited number 
of devices, but these areas may not specifically represent unique high 
occurrence locations warranting geographic protection beyond existing 
Navy protective measures. Current funded Navy passive acoustic 
monitoring for beaked whales continues to report limited BW43 
detections (Rice et al. 2017, 2018, 2019, 2020).
    The Navy has been training and testing in and around the Northern 
Catalina Basin and waters southeast of Santa Catalina Island with the 
same systems for over 40 years, and there is no evidence of any adverse 
impacts having occurred and no indications that Navy training and 
testing has had any adverse impacts on populations of beaked whales in 
Southern California. The main source of anthropogenic noise in the 
Catalina Basin and waters south of San Clemente Island are associated 
with commercial vessel traffic concentrated in the northbound and 
southbound lanes of the San Pedro Channel that runs next to Santa 
Catalina Island and leads to and from the ports of Los Angeles/Long 
Beach and other commercial traffic from San Diego and ports to the 
north and south of Southern California. These waters in and around 
Northern Catalina Basin and waters southeast of Santa Catalina Island 
are critical to the Navy's training and testing activities, and so it 
is not practicable to limit or reduce access or preclude activities 
within that water space in the SOCAL portion of the HSTT Study Area.
    NMFS and the Navy considered the Santa Catalina Basin area and 
Perrin's beaked whales, as described in Appendix K (Geographic 
Mitigation Assessment), Section K.7.2.3 (Catalina Basin) and K.7.2.7 
(Northern Catalina Basin and the San Clemente Basin) of the 2018 HSTT 
FEIS/OEIS. Also see Appendix K (Geographic Mitigation Assessment), 
Section K.7.2.7.2 (Northern Catalina Basin and Waters Southeast of 
Catalina Island Perrin's Beaked Whale Habitat Mitigation 
Considerations) of the 2018 HSTT FEIS/OEIS for additional information 
regarding this species. Additional limitations as discussed in Appendix 
K (Geographic Mitigation Assessment) would limit training and impact 
readiness. Given that there is no evidence of impacts to the population 
of beaked whales in the area, and low potential occurrence of Perrin's 
beaked whales in the Southern California portion of the HSTT Study 
Area, geographic mitigation would not effectively balance a reduction 
of biological impacts with an acceptable level of impact on military 
readiness activities and, as described in the Mitigation Measures 
section of this final rule, NMFS has included the mitigation 
requirements necessary to achieve the least practicable adverse impact 
on the affected species or stocks and their habitat. As noted in 
Appendix K (Geographic Mitigation Assessment) and Chapter 5, Section 
5.3 (Procedural Mitigation to be Implemented) of the 2018 HSTT FEIS/
OEIS, the Navy will continue to implement procedural mitigation 
measures throughout the HSTT Study Area.
    Comment 58: In a comment on the 2018 HSTT proposed rule, Commenters 
recommended additional mitigation areas for important fin whale habitat 
off Southern California. The Commenters recommended that the waters 
between the 200 m and 1,000 m isobaths be assessed for time-area 
management so that, at minimum, ship strike awareness measures for fin 
whales can be implemented during the months of November through 
February, when the whales aggregate in the area.
    Response: As described and detailed in the 2018 HSTT FEIS/OEIS, the 
Navy implements a number of ship-strike risk reduction measures for all 
vessels, in all locations and seasons, and for all marine mammal 
species. New research by [Scaron]irovi[cacute] et al. (2017) supports a 
hypothesis that between the Gulf of California and Southern California, 
there could be up to four distinct sub-populations based on fin whale 
call types, including a Southern California resident population. There 
is also evidence that there can be both sub-population shifts and 
overlap within Southern California ([Scaron]irovi[cacute] et al., 
2017). Scales et al. (2017) also postulated two Southern California 
sub-populations of fin whales based on satellite tagging and habitat 
modeling. Scales et al. (2017) stated that some fin whales may not 
follow the typical baleen whale migration paradigm, with some 
individuals found in both warm, shallow nearshore waters less than 500 
m, and deeper cool waters over complex seafloor topographies. 
Collectively, the author's spatial habitat models with highest 
predicted occurrence for fin whales cover the entire core training and 
testing portion of the SOCAL portion of the HSTT Study Area, not just 
areas between 200 and 1,000 m. Results from Navy-funded long-term 
satellite tagging of fin whales in Southern and Central California 
still shows some individual fin whales engage in wide-ranging movements 
along the U.S. West Coast, as well as large daily movements well within 
subareas (Mate et al., 2017; Schorr et al., 2020). In support of 
further refining the science on Southern California fin whales, Falcone 
and Schorr (2014) examined fin whale movements through photo ID and 
short-to-medium term (days-to-several weeks) satellite tag tracking 
under funding from the Navy. The authors conducted small boat surveys 
from June 2010 through January 2014, approximately three-and-a-half 
years. Of interest in terms of the comment and the 200-1,000 m isobaths 
occurrence, more fin whale tag locations were reported off the Palos 
Verdes Peninsula and off of the Los Angeles/Long Beach commercial 
shipping ports in fall, both areas north of and outside of the Navy's 
SOCAL Range Complex. Compared to the above areas, there were not as 
many tag locations in the similar isobaths region off San Diego 
associated

[[Page 41824]]

with the Navy range area. Falcone and Schorr (2014) did document an 
apparent inshore-offshore distribution between Winter-Spring and 
Summer-Fall. Given the apparent resident nature of some fin whales in 
Southern California as discussed in Falcone and Schorr (2014), Scales 
et al. (2017), and [Scaron]irovi[cacute] et al. (2017), it remains 
uncertain if the inshore-offshore seasonal pattern as well as sub-
population occurrence will persist into the future, or if fin whales 
will change distribution based on oceanographic impacts on available 
prey (e.g. El Nino, climate change, etc.). The efforts from Falcone and 
Schorr on fin whales began in 2010, and Navy monitoring funding to 
further refine fin whale population structure and occurrence within 
Southern California is planned to continue for the duration of this 
rule.
    The data from the various single bottom-mounted passive acoustic 
devices used in the analysis to support this comment are not continuous 
and have various periodicities for which data have been collected. Many 
of these devices are purposely placed in 200-1,000 m of water. Given 
these are point sources of data, they may or may not be indicative of 
fin whale calling or presence at other locations within Southern 
California without devices. Passive acoustic analysis is only useful 
for those individuals that are calling and may not indicate total 
population occurrence. Low-frequency fin whale calls by their very 
nature have relatively long underwater propagation ranges so detections 
at a single device could account for individuals 10-50 miles away if 
not further, depending on local propagation conditions. This would mean 
calling whales are not in the 200-1,000 m area. [Scaron]irovi[cacute] 
et al. (2015) acknowledge in discussing their data biases, that their 
use of ``call index'' may best indicate a period of peak calling. But 
fin whales produce multiple call types depending on behavioral state. 
Based on technology limitations, some fin whale call types were not 
included in [Scaron]irovi[cacute] et al. (2015). The following are 
factors supporting NMFS' determination that ship speed reduction is 
specifically not warranted in this area.
    1. The study cited by a Commenter ([Scaron]irovi[cacute] et al., 
2015) and used as the basis for ``Figure 3'' concerns trends seen 
within the Southern California Bight, not exclusively the SOCAL Range 
Complex;
    2. The research used as the basis for Figure 3 was funded by the 
Navy to develop baseline information for the areas where Navy trains 
and tests and was by no means designed to or otherwise intended as a 
representative sample of all waters off California or the entire 
habitat of the fin whale population in the area;
    3. It is not correct to assume detected vocalizations (a ``call 
index'') reported in [Scaron]irovi[cacute] et al. (2015) for fin whales 
equates with where fin whales are aggregated in the Southern California 
Bight. For example, the acoustic monitoring data did not pick up or 
otherwise correspond to the observed seasonal distribution shift of fin 
whales indicated by visual survey data covering the same time periods 
(Campbell et al., 2015; Douglas et al., 2014);
    4. [Scaron]irovi[cacute] et al. (2015) make no such claim of 
aggregations during the winter months but instead compare call index 
rates and state that the purpose for the paper was to demonstrate that 
passive acoustics can be a powerful tool to monitor population trends, 
not relative abundances;
    5. There is no science to support the contention that fin whales 
are ``at particular risk of ship-strike on the naval range.'' Two fin 
whales were struck by the Navy in 2009 in the SOCAL portion of the HSTT 
Study Area as Navy noted in Appendix K (Geographic Mitigation 
Assessment), but since that time there have been no fin whales struck 
or any species of whales struck despite a documented increase in the 
fin whale population inhabiting the area (Barlow, 2016; Moore and 
Barlow, 2011; Smultea and Jefferson, 2014). Furthermore, one of those 
vessel strikes occurred at the end of the recommended mitigation 
timeframe (February) and the other well outside the time period (May), 
so the proposed mitigation would only have been marginally effective, 
if at all. Neither of these Navy fin whale strike locations were close 
to shore (both >50-60 Nmi from shore), or associated with coastal 
shipping lanes. Based on an analysis of Navy ship traffic in the HSTT 
Study Area between 2011 and 2015, median speed of all Navy vessels 
within Southern California is typically already low, with median speeds 
between 5 and 12 kn (CNA, 2016). This includes areas within and outside 
of 200-1,000 m within Southern California, with slowest speeds closer 
to the coast; and
    6. As presented in the 2018 HSTT FEIS/OEIS, fin whales are present 
off all the waters of Southern California year-round 
([Scaron]irovi[cacute] et al., 2015, 2017). Using available 
quantitative density and distribution mapping, the best available 
science, and expert elicitation, definitive areas of importance for fin 
whales could not be determined by a panel of scientists specifically 
attempting to do so (Calambokidis et al., 2015).
    Navy vessels already operate at slower speeds given a particular 
transit or activity need. This also includes a provision to avoid large 
whales by 500 yd, so long as safety of navigation and safety of 
operations is maintained. Previously, the Navy commissioned a vessel 
density and speed report for HSTT (CNA, 2016). Based on an analysis of 
Navy ship traffic in the HSTT Study Area between 2011 and 2015, median 
speed of all Navy vessels within Southern California is typically 
already low, with median speeds between 5 and 12 kn (CNA, 2016). The 
slowest speeds occurred closer to the coast and islands.
    Therefore, NMFS has determined that vessel speed restrictions 
within 200-1,000 m are not warranted given the wide range of fin whale 
movements along the U.S. West Coast including areas within and outside 
of 200-1,000 m contours, sometimes large-scale daily movements within 
regional areas as documented from Navy-funded satellite tagging, the 
current lack of ship strike risk from Navy vessels in Southern 
California (as well as throughout the HSTT Study Area) (2010-2019), the 
lower training and testing ship speeds Navy uses within the HSTT Study 
Area, and existing Navy mitigation measures including provisions to 
avoid large whales by 500 yds where safe to do so.
    In addition, the Navy agreed to send out seasonal awareness 
messages of fin, blue, and gray whale occurrence to improve awareness 
of all vessels operating to the presence of these species in SOCAL from 
November through May (fin whales), November through March (gray 
whales), and June through October (blue whales). The Navy will also 
review WhaleWatch, a program coordinated by NMFS' West Coast Region as 
an additional information source to inform the drafting of the seasonal 
awareness message to alert vessels in the area to the possible presence 
of concentrations of large whales, including fin whales in SOCAL.
Hawaii Areas
    Comment 59: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that the Navy consider the following as it plans 
to conduct activities in the HSTT Study Area. The Commenter notes units 
of the NPS system that occur near training and testing areas around 
Hawaii and identifies which may be affected by noise. The Units are: 
Kaloko-Honokohau National Historical Park (NHP), Pu'uhonua o Honaunau 
NHP,

[[Page 41825]]

Pu'ukolhola Heiau National Historic Site, Kalaupapa NHP, Hawaii 
Volcanoes NP, Haleakala NP, and the World War II Valor in the Pacific 
National Monument.
    Response: National Parks and National Monuments are addressed in 
Chapter 6 of the 2018 HSTT FEIS/OEIS. Kalaupapa NHP is discussed in 
Comment 60 below. No planned activities overlap with Kaloko-Honokohau 
NHP; therefore, no impacts are expected within the Kaloko-Honokohau 
NHP. The Pu'uhonua o Honaunau NHP, Haleakala NP, and Pu'ukolhola Heiau 
National Historic Site are not specifically addressed in Chapter 6 of 
the 2018 HSTT FEIS/OEIS, but none of these sites appear to contain any 
marine waters. The Navy's planned activities do not occur on land 
except in designated training areas on Navy properties (i.e., for 
amphibious assaults, etc.); therefore, there are no activities that 
overlap with these sites and no impacts are expected. For the Hawaii 
Volcanoes NP, the Navy's planned activities addressed in the 2018 HSTT 
FEIS/OEIS do not include aircraft or unmanned aerial systems flights 
over or near the Hawaii Volcanoes National Park; therefore, no impacts 
are expected. The World War II Valor in the Pacific Monument is for the 
USS Arizona, which is a Navy war memorial. No activities occur within 
the boundary of the site itself, and the monument was not designated to 
protect marine species. There are training and testing activities that 
occur within Pearl Harbor as a whole, and impacts to marine mammals in 
the waters of Pearl Harbor were included in the Navy's proposed 
activities and therefore analyzed by NMFS in the final rule.
    Comment 60: In a comment on the 2018 HSTT proposed rule, a 
Commenter noted the presence of marine mammal species in the Kalaupapa 
NHP (on the north shore of Molokai), and is concerned about potential 
take of protected species that inhabit water out to 1,000 fathoms, and 
recommended the Navy consider alternate training areas to avoid impacts 
to these species. Species that occur year-round include the false 
killer whale, sperm whale, pygmy sperm whale, spinner dolphin, and 
bottlenose dolphin. Humpback whales are seasonal visitors from November 
to April. The Hawaiian monk seal pups are within the Kalaupapa NHP 
during the spring and summer.
    Response: Part of the Kalaupapa NHP (northern portion) is protected 
by the measures employed inside the 4-Islands Region Mitigation Area 
such as year-round prohibition on explosives and no use of MF1 surface 
ship hull mounted mid-frequency active sonar from November 15 through 
April 15.
    We note, however, that the majority of the Kalaupapa NHP is not in 
the 4-Islands Region Mitigation Area as it is mainly land-based, but 
just outside it. The Kalaupapa NHP was designated to protect the two 
historic leper colonies on the property and was not designated with the 
purpose of protecting marine species. The boundaries of the Kalaupapa 
NHP extend a quarter mile offshore. The Navy does propose conducting 
activities associated with the planned activities in the boundary of 
the Kalaupapa NHP. There would be no effect to Hawaiian monk seal 
pupping on NHP land as the Navy does not have any planned activities in 
the boundary of the Kalaupapa NHP, especially on land. The Navy's 
planned activities do not include any land-based activities except for 
a few activities which are conducted on designated Navy property (i.e., 
amphibious assaults on Silver Strand, etc.). Further, as the sea space 
adjacent to the Kalaupapa NHP is not an established training or testing 
area, it is unlikely naval activity would occur in this area.
    Comment 61: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended expanding the Hawaii Island Mitigation Area 
westward to protect resident Cuvier's beaked whales and rough-toothed 
dolphins. The boundaries of the Hawaii Island Mitigation Area should be 
expanded westward to remain consistent with the boundaries of the BIAs 
defined in Baird et al. (2015), which informed the boundaries of 
Conservation Council Settlement Areas 1-C and 1-D. This expansion will 
cover habitat for Cuvier's beaked whales and toothed dolphins that are 
resident around the Big Island.
    Response: Please see the Mitigation Measures, Brief Comparison of 
2015 Settlement Mitigation and Final HSTT Mitigation in the Rule 
section of the 2018 HSTT final rule, which discusses NMFS analysis and 
decisions in regard to required mitigation areas with explicit 
consideration of areas that were previously required by the settlement 
agreement. Analyses of the marine mammal species mentioned in the 
comment and considered within the Hawaii Island Mitigation Area are 
discussed in Appendix K (Geographic Mitigation Assessment), Section K.3 
(Biologically Important Areas within the Hawaii Range Complex Portion 
of the HSTT Study Area) and Sections K.5.1 (Settlement Areas Within the 
Hawaii Portion of the HSTT Study Area) through K.5.4 (Proposed 
Mitigation Areas that Overlap the Hawaii Portion of the HSTT Settlement 
Agreement Areas) of the 2018 HSTT FEIS/OEIS. NMFS concurs with the 
analysis included in this document and has used it to support our 
findings in this rule. Additional information on the marine mammals 
mentioned in the comment is also provided in the species-specific sub-
sections in Chapter 3, Section 3.7.2 (Affected Environment) of the 2018 
HSTT FEIS/OEIS. Based on these analyses, the Navy will implement 
additional mitigation within the Hawaii Island Mitigation Area (year-
round), as described in the Mitigation Measures section in the 2018 
HSTT final rule and this rule, to further avoid or reduce impacts on 
marine mammals from acoustic and explosive stressors from the planned 
activities.
    The mitigation requirement of prohibiting the use of explosives 
year-round during training and testing across the entire Hawaii Island 
Mitigation Area satisfies the previous mitigation requirement of a 
prohibition on the use of in-water explosives for training and testing 
activities of the Settlement Agreement for Areas 1-A, 1-C, and 1-D, and 
further extends that requirement to the Alenuih[amacr]h[amacr] Channel 
(Area 1-B). The Hawaii Island Mitigation Area still includes 100 
percent of Settlement Areas 1-C and 1-D and includes a large majority 
of the BIAs for Cuvier's beaked whale (Hawaii Island BIA) and rough-
toothed Dolphins (Hawaii Island BIA) (the areas in question by this 
comment). Particularly, it covers 93.30 percent of the Cuvier's beaked 
whale BIA westward of Hawaii Island and 83.58 percent of rough-toothed 
dolphins Hawaii Island BIA westward of Hawaii Island.
    Only the northern portion of the Cuvier's beaked whale BIA in 
Alenuihaha Channel and a smaller offshore portion of the BIA west of 
Hawaii are not covered by mitigations included in the Hawaii Island 
Mitigation Area on the west and east of Hawaii Island. The BIA is based 
on the known range of the island-associated population, and the authors 
suggest that ``the range of individuals from this population is likely 
to increase as additional satellite-tag data become available'' (Baird 
et al., 2015). Cuvier's beaked whales are not expected to be displaced 
from their habitat due to training and testing activities further 
offshore in these small areas of the biologically important area, given 
that the BIA covers 23,583 km\2\, is unbroken and continuous 
surrounding the island, and the BIA likely underrepresents their range. 
The small portion of the BIA that does not overlap the Hawaii Island 
Mitigation Area is offshore, and according to the most recent stock

[[Page 41826]]

assessment approximately 95 percent of all sighting locations were 
within 45 km of shore. Additionally, consequences to individuals or 
populations are not unknown. No PTS is estimated or authorized. A small 
number of TTS and Level B behavioral harassment takes for Cuvier's 
beaked whales are estimated across the entire Hawaii portion of the 
HSTT Study Area due to acoustic stressors. Most of the TTS and Level B 
behavioral harassment takes for Cuvier's beaked whales are associated 
with testing in the Hawaii Temporary Operating Area, impacting the 
pelagic population (see Figure 3.7-36 of the 2018 HSTT FEIS/OEIS). It 
is extremely unlikely that any modeled takes would be of individuals in 
this small portion of the BIA that extends outside the Hawaii Island 
Mitigation Area.
    Long-term and relatively comprehensive research has found no 
evidence of any apparent effects while documenting the continued 
existence of multiple small and resident populations of various species 
as well as long-term residency by individual beaked whales spanning the 
length of the current studies that exceed a decade. Further, the Navy 
has considered research showing that in specific contexts (such as 
associated with urban noise, commercial vessel traffic, eco-tourism, or 
whale watching, Chapter 3, Section 3.7.2.1.5.2 (Commercial Industries)) 
of the 2018 HSTT FEIS/OEIS that chronic repeated displacement and 
foraging disruption of populations with residency or high site fidelity 
can result in population-level effects. As also detailed in the 2018 
HSTT FEIS/OEIS, however, the Navy training and testing activities do 
not equate with the types of disturbance in this body of research, nor 
do they rise to the level of chronic disturbance where such effects 
have been demonstrated because Navy activities are typically sporadic 
and dispersed. There is no evidence to suggest there have been any 
population-level effects in the waters around Oahu, Kauai, and Niihau 
or anywhere in the HSTT Study Area. In the waters around Oahu, Kauai, 
and Niihau, documented long-term residency by individuals and the 
existence of multiple small and resident populations are precisely 
where Navy training and testing have been occurring for decades, 
strongly suggesting a lack of significant impact to those individuals 
and populations from the continuation of Navy training and testing.
    Mark-recapture estimates derived from photographs of rough-toothed 
dolphins taken between 2003 and 2006 resulted in a small and resident 
population estimate of 198 around the island of Hawaii (Baird et al., 
2008), but those surveys were conducted primarily with 40 km of shore 
and may underestimate the population. Data do suggest high site 
fidelity and low population size for the island-associated population. 
There are no tagging data to provide information about the range of the 
island-associated population; the BIA is based on sighting locations 
and encompasses 7,175 km\2\. Generally, this species is typically found 
close to shore around oceanic islands. Only approximately half of the 
BIA offshore is not covered by the Hawaii Island Mitigation Area, where 
the BIA overlaps with special use airspace. Consequences to individuals 
or populations are not unknown. No PTS is estimated or authorized. Some 
TTS and Level B behavioral harassment takes due to acoustic stressors 
are authorized for this species across the entire HSTT Study Area (see 
Figure 3.7-66 of the 2018 HSTT FEIS/OEIS). Significant impacts on 
rough-toothed dolphin natural behaviors or abandonment due to training 
with sonar and other transducers are unlikely to occur within the small 
and resident population area. A few minor to moderate TTS or Level B 
behavioral harassment takes to an individual over the course of a year 
are unlikely to have any significant costs or long-term consequences 
for that individual, and nothing in the planned activities is expected 
to cause a ``catastrophic event.'' The Navy operating areas west of 
Hawaii Island are used commonly for larger events for a variety of 
reasons described further in Section K.3 (Appendix K of the 2018 HSTT 
FEIS/OEIS, Biologically Important Areas Within the Hawaiian Range 
Complex Portion of the HSTT Study Area) (e.g., the relatively large 
group of seamounts in the open ocean offers challenging bathymetry in 
the open ocean far away from civilian vessel traffic and air lanes 
where ships, submarines, and aircraft are completely free to maneuver) 
and sonar may be used by a variety of platforms. Enlarging the Hawaii 
Island Mitigation Area is not anticipated to realistically reduce 
adverse impacts. Expanding the Hawaii Island Mitigation Area has a 
limited likelihood of further reducing impacts on marine mammal species 
or stocks and their habitat, while these open ocean operating areas are 
important for training and testing and, in consideration of these 
factors (and the broader least practicable adverse impact 
considerations discussed in the introduction), NMFS has determined that 
requiring this additional mitigation is not appropriate.
    Comment 62: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended limiting MTEs to reduce cumulative exposure in 
the Hawaii Island Mitigation Area.
    Response: Prohibiting MTEs outright or spatially separating them 
within the Hawaii Island Mitigation Area was proposed as additional 
mitigation to ensure that ``marine mammal populations with highly 
discrete site fidelity . . . are not exposed to MTEs within a single 
year.'' The goal of geographic mitigation is not to be an absolute, 
outright barrier and stop exposing animals to exercises per se; it is 
to reduce adverse impacts to the maximum extent practicable. Impacts 
associated with MTEs, including cumulative impacts, are addressed in 
the 2018 HSTT proposed and final rules, as well as in Chapters 3 
(Affected Environment and Environmental Consequences) and Chapter 4 
(Cumulative Impacts) of the 2018 HSTT FEIS/OEIS. The Navy's 
quantitative analysis using the best available science has determined 
that training and testing activities will not have population-level 
impacts on any species, and the operational and time/area mitigation 
measures required by the MMPA rule further reduce impacts on marine 
mammals and their habitat. As determined in Chapter 3, Section 3.7.4 
(Summary of Potential Impacts on Marine Mammals) of the 2018 HSTT FEIS/
OEIS, it is not anticipated that the planned activities will result in 
significant impacts to marine mammals. To date, the findings from 
research and monitoring and the regulatory conclusions from previous 
analyses by NMFS are that the majority of impacts from Navy training 
and testing activities are not expected to have deleterious impacts on 
the fitness of any individuals or long-term consequences to populations 
of marine mammals the Commenter references.
    MTEs cannot be further limited in space or time within the Hawaii 
Island Mitigation Area, given that those activities are specifically 
located to leverage particular features like the Alenuihaha Channel and 
the approaches to Kawaihae Harbor. This recommendation is not, 
therefore, appropriate in consideration of NMFS' least practicable 
adverse impact standard.
    To limit impacts, the Navy will not conduct more than 300 hrs of 
MF1 surface ship hull-mounted MFAS or 20 hrs of MF4 dipping sonar, or 
use explosives that could potentially result in takes of marine mammals 
during training and testing in the Hawaii Island Mitigation Area.

[[Page 41827]]

    Comment 63: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended prohibiting or restricting other sources of MFAS 
in the Hawaii Island Mitigation Area including prohibiting the use of 
helicopter-deployed MFAS in the Hawaii Island Mitigation Area.
    Response: The Navy is already limiting other sources of MFAS. 
Between the application and the proposed rule, the Navy added new 
mitigation that includes a limit to the annual use of helicopter 
dipping sonar in the Hawaii Island Mitigation Area. Specifically, the 
Navy will not conduct more than 20 hrs of MF4 dipping sonar that could 
potentially result in takes of marine mammals during training and 
testing. Helicopters deploy MFAS from a hover position in bouts 
generally lasting under 20 minutes, moving rapidly between sequential 
deployment and their duration of use and source level (217 dB) are 
generally well below those of hull-mounted frequency sonar (235 dB). 
All locations within the HSTT Study Area have been used for Navy 
training and testing for decades. There has been no scientific evidence 
to indicate the Navy's activities are having adverse effects on 
populations of marine mammals, many of which continue to increase in 
number or are maintaining populations based on what regional conditions 
can support. Navy research and monitoring funding continues within the 
HSTT Study Area under current NMFS MMPA and ESA permits, and is planned 
through the duration of any future permits. Given the lack of effects 
to marine mammal populations in the HSTT Study Area from larger, more 
powerful surface ship sonars, the effects from intermittent, less 
frequent use of lower powered MF dipping sonar or other MFAS would also 
not significantly affect small and resident populations.
    Comment 64: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended extending the 4-Islands Region Mitigation Area 
westward to encompass the Humpback Whale Special Reporting Area in 
Kaiwi Channel. Additionally, they argue that the 4-Island Region 
Mitigation Area is inadequate to protect endangered Main Hawaiian 
Island insular false killer whales as the Main Hawaiian Island insular 
false killer whale is highly range-restricted to certain high-use 
areas, one of which includes the ESA critical habitat and the BIA north 
of Maui and Molokai (``False killer whale Hawaii Island to Niihau'' 
BIA).
    Response: In regard to extending the 4-Islands Region Mitigation 
Area westward to encompass the Humpback Whale Special Reporting Area in 
Kaiwi Channel, reducing or limiting Navy training and testing in the 
Southeast Oahu area is not likely to be effective in reducing or 
avoiding impacts given that the Navy does not routinely conduct 
activities that involve sonar or other transducers or explosives in 
this portion of the Humpback Whale Reproduction Area (included in the 
Humpback Whale Special Reporting Area in Kaiwi Channel). The portion of 
the special reporting area that extends into Kaiwi Channel over Penguin 
Bank (equivalent to settlement area 2A) is generally not a higher use 
area for Main Hawaiian Island insular false killer whales and does not 
overlap significantly with the BIA. As presented in Chapter 3 of the 
2018 HSTT FEIS/OEIS (Affected Environment and Environmental 
Consequences), which supports NMFS' analysis for the rule, the Navy's 
quantitative analysis indicates that significant impacts on false 
killer whale natural behaviors or abandonment due to training with 
sonar and other transducers are unlikely to occur within the entire 
small and resident population area, let alone in the small sub-portion 
of the biologically important area that overlaps the proposed 
extension. Additionally, most of the modeled takes are for the Hawaii 
pelagic population of false killer whale (see Figure 3.7-46 and Table 
3.7-31 in the 2018 HSTT FEIS/OEIS). Also, as described in more detail 
in Appendix K of the 2018 HSTT FEIS/OEIS, due to training and testing 
needs, the expansion of this area is considered impracticable.
    Comment 65: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended extending the seasonal restrictions to year-round 
restrictions in the 4-Islands Region Mitigation Area and proposed 
extending the Mitigation Area into the Kaiwi Channel Humpback Whale 
Special Reporting Area.
    Response: The proposed extension of the 4-Islands Region Mitigation 
Area into Kaiwi Channel was addressed above in Comment 64. The 
additional expansion requested in the comment is not expected to reduce 
adverse impacts to an extent that would outweigh the negative impacts 
if unit commanders were unable to conduct unit-level training and 
testing, especially as they pass over Penguin Bank while transiting 
between Pearl Harbor and other parts of the Study Area. Prohibiting 
mid-frequency active sonar would preclude the Submarine Command Course 
from meeting its objectives and leveraging the important and unique 
characteristics of the 4-Islands Region, as described in multiple 
sections of Appendix K of the 2018 HSTT FEIS/OEIS (e.g., Section 
K.3.1.6 (4-Islands Region and Penguin Bank Humpback Whale Reproduction 
Area, and Settlement Area 2-A and 2-B)), which NMFS concurs with and 
used to support the mitigation analysis for the rule. Penguin Bank is 
particularly used for shallow water submarine testing and anti-
submarine warfare training because of its large expanse of shallow 
bathymetry. The conditions in Penguin Bank offer ideal bathymetric and 
oceanographic conditions allowing for realistic training and testing 
and serve as surrogate environments for active theater locations.
    Additionally, this mitigation would further increase reporting 
requirements. As discussed in Chapter 5 (Mitigation) Section 5.5.2.6 
(Increasing Reporting Requirements) of the 2018 HSTT FEIS/OEIS, the 
Navy developed its reporting requirements in conjunction with NMFS, 
balancing the usefulness of the information to be collected with the 
practicability of collecting it. An increase in reporting requirements 
as a mitigation would draw the event participants' attention away from 
the complex tactical tasks they are primarily obligated to perform 
(such as driving a warship), which would adversely impact personnel 
safety, public health and safety, and the effectiveness of the military 
readiness activity. Expanding the Mitigation Area and extending the 
restrictions is not, therefore, appropriate in consideration of NMFS' 
least practicable adverse impact standard.
    Comment 66: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended implementing vessel speed restrictions within the 
4-Islands Region Mitigation Area.
    Response: This mitigation measure was proposed to address impacts 
on humpback whales due to both ship noise and ship strikes. As 
described and detailed in the Mitigation Measures section of the 2018 
HSTT final rule, this rule, and the 2018 HSTT FEIS/OEIS, the Navy 
already implements a number of ship-strike risk reduction measures for 
all vessels, in all locations and seasons, and for all marine mammal 
species. The Navy cannot implement mitigation that restricts vessel 
speed during training or testing in the HSTT Study Area because it is 
not practicable. Vessels must be able to maneuver freely as required by 
their tactics in order for training events to be effective. Imposition 
of vessel speed restrictions would interfere with the Navy's ability to 
complete tests that must occur in specific bathymetric and oceanic 
conditions and at specific speeds. Navy vessel operators must test and 
train with vessels in such a manner that ensures their ability to 
operate

[[Page 41828]]

vessels as they would in military missions and combat operations 
(including being able to react to changing tactical situations and 
evaluate system capabilities). Furthermore, testing of new platforms 
requires testing at the full range of propulsion capabilities and is 
required to ensure the delivered platform meets requirements. Based on 
an analysis of Navy ship traffic in the HSTT Study Area between 2011 
and 2015, median speed of all Navy vessels within Hawaii is typically 
already low, with median speeds between 8-16 kn (CNA, 2016). Speed 
restrictions in the Cautionary Area (renamed the 4-Islands Region 
Mitigation Area) are unwarranted given the movement of all social 
groups throughout the islands outside the Mitigation Area, the current 
lack of ship strike risk from Navy vessels in Hawaii (2010-2017), the 
already safe training and testing ship speeds the Navy uses within the 
HSTT Study Area, and existing Navy mitigation measures, including 
provisions to avoid large whales by 500 yards where safe to do so. 
Implementing speed restrictions in the Mitigation Area is not, 
therefore, appropriate in consideration of NMFS' least practicable 
adverse impact standard.
    Information on the response of baleen whales to vessel noise is 
presented in Section 3.7.3.1.1.5 (Behavioral Reactions) and Section 
3.7.3.1.5 (Impacts from Vessel Noise) of the 2018 HSTT FEIS/OEIS, which 
supports NMFS analyses. Impacts, if they did occur, would most likely 
be short-term masking and minor behavioral responses. Therefore, 
significant impacts on humpback whale reproductive behaviors from 
vessel noise associated with training activities are not expected. Navy 
vessels are intentionally designed to be quieter than civilian vessels, 
and ship speed reductions are not expected to reduce adverse impacts on 
humpback whales due to vessel noise.
    Comment 67: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended prohibiting the use of in-water explosives in the 
4-Islands Region Mitigation Area.
    Response: The Navy has agreed to implement a year-round restriction 
on the use of in-water explosives that could potentially result in 
takes of marine mammals during training and testing. Should national 
security present a requirement to use explosives that could potentially 
result in the take of marine mammals during training or testing, naval 
units will obtain permission from the appropriate designated Command 
authority prior to commencement of the activity. The Navy will provide 
NMFS with advance notification and include the information (e.g., sonar 
hours or explosives usage) in its annual activity reports submitted to 
NMFS.
    Comment 68: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended prohibiting other sources of MFAS in the 4-
Islands Region Mitigation Area.
    Response: NMFS fully assessed the mitigation for the 4-Islands 
Region Mitigation Area (see the Mitigation Measures section in the 2018 
HSTT final rule). As the Navy has described, this area provides a 
unique and irreplaceable shallow water training capability for units to 
practice operations in littoral areas that are both shallow and 
navigationally constrained (2018 HSTT FEIS/OEIS Appendix K (Geographic 
Mitigation Assessment), Section K.3.3.1.6). The 4-Islands Region 
provides an environment for anti-submarine warfare search, tracking and 
avoidance of opposing anti-submarine warfare forces. The bathymetry 
provides unique attributes and unmatched opportunity to train in 
searching for submarines in shallow water. Littoral training allows 
units to continue to deploy improved sensors or tactics in littoral 
waters. In the Hawaii portion of the HSTT Study Area specifically, 
anti-submarine warfare training in shallow water is vitally important 
to the Navy since diesel submarines typically hide in that extremely 
noisy and complex marine environment (Arabian Gulf, Strait of Malacca, 
Sea of Japan, and the Yellow Sea all contain water less than 200 m 
deep). There is no other area in this portion of the HSTT Study Area 
with the bathymetry and sound propagation analogous to seas where the 
Navy conducts real operations that this training could relocate to. The 
Navy cannot conduct realistic shallow water training exercises without 
training in and around the 4-Islands Region Mitigation Area. In 
addition, this area includes unique shallow water training 
opportunities for unit-level training, including opportunity to 
practice operations in littoral areas that are both shallow, and 
navigationally constrained, and in close proximity to deeper open ocean 
environments. While MFAS is used infrequently in this area, a complete 
prohibition of all active sonars would impact Navy training readiness 
in an area identified as important for the Navy based on its unique 
bathymetry. However, the Navy recognizes the biological importance of 
this area to humpback whales during the reproductive season and in the 
4-Islands Region Mitigation Area the Navy will not use MF1 surface 
hull-mounted MFAS (the source that results in, by far, the highest 
numbers of take) from November 15 through April 15 or use explosives in 
this area at any time of the year. While the Navy has been training and 
testing in the area with the same basic systems for over 40 years, 
there is no evidence of any adverse impacts having occurred, and there 
are multiple lines of evidence demonstrating the small odontocete 
population high site fidelity to the area.
    Comment 69: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended prohibiting the use of helicopter-deployed mid-
frequency active sonar in the 4-Islands Region Mitigation Area.
    Response: The Commenter's request to prohibit ``air-deployed'' MFAS 
is based on one paper (Falcone et al., 2017), which is a Navy-funded 
project designed to study the behavioral responses of a single species, 
Cuvier's beaked whales, to MFAS. The Navy relied upon the best science 
that was available to develop behavioral response functions for beaked 
whales and other marine mammals in consultation with NMFS for the 2018 
HSTT FEIS/OEIS. NMFS and the Navy have reviewed the article and concur 
that neither this article nor any other new information that has been 
published or otherwise conveyed since the 2018 HSTT proposed rule was 
published would fundamentally change the assessment of impacts or 
conclusions in the 2018 HSTT FEIS/OEIS or in this rulemaking. 
Nonetheless, the new information and data presented in the new 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. The new information and data 
presented in the article was thoroughly reviewed when it became 
available and further considered in discussions with some of the 
paper's authors following its first presentation in October 2017 at a 
recent scientific conference. Many of the variables requiring further 
analysis for beaked whales and dipping sonar impact assessment are 
still being researched under continued Navy funding through 2023.
    There are no beaked whale biologically important areas in the 4-
Islands Region Mitigation Area, and the Mitigation Area is generally 
shallower than beaked whales' preferred habitat. Behavioral responses 
of beaked whales from dipping and other sonars cannot be universally 
applied to other marine mammal species. Research indicates that there 
are distinct individual

[[Page 41829]]

variations as well as strong behavioral state considerations that 
influence any response or lack of response (Goldbogen et al., 2013; 
Harris et al., 2017). Therefore, it is expected that other species 
would have highly variable individual responses ranging from some 
response to no response to any anthropogenic sound. This variability is 
accounted for in the Navy's current behavioral response curves 
described in the 2018 HSTT FEIS/OEIS and supporting technical reports.
    Furthermore, the potential effects of dipping sonar have been 
rigorously accounted for in the Navy's analysis. Parameters such as 
power level and propagation range for typical dipping sonar use are 
factored into HSTT acoustic impact analysis along with guild specific 
criteria and other modeling variables, as detailed in the 2018 HSTT 
FEIS/OEIS and associated technical reports for criteria and acoustic 
modeling. Further, due to lower power settings for dipping sonar, 
potential impact ranges of dipping sonar are significantly lower than 
surface ship sonars. For example, the HSTT average modeled range to TTS 
of dipping sonar for a 1-second ping on low-frequency cetacean (i.e., 
blue whale) is 77 m, and for mid-frequency cetaceans including beaked 
whales is 22 m (2018 HSTT FEIS/OEIS Table 3.7-7). This range is easily 
monitored for marine mammals by a hovering helicopter and is accounted 
for in the Navy's proposed mitigation ranges for dipping sonars (200 
yds or 183 m). Limited ping time (i.e., less dipping sonar use as 
compared to typical surface ship sonar use) and lower power settings 
therefore would limit the impact from dipping sonar to any marine 
mammal species.
    This is an area of extremely low use for air-deployed MFAS. 
Prohibiting air-deployed MFAS in the Mitigation Area would not be any 
more protective to marine mammal populations generally, or the Main 
Hawaiian Islands insular false killer whale in particular, than 
currently implemented procedural mitigation measures for air-deployed 
MFAS and is not, therefore, appropriate in consideration of NMFS' least 
practicable adverse impact standard.
    Comment 70: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended prohibiting use of LFAS in the 4-Islands Region 
Mitigation Area.
    Response: The Commenter suggested that ``Baleen whales are 
vulnerable to the impacts of LFAS, particularly in calving areas where 
low-amplitude communication calls between mothers and calves can be 
easily masked.'' As described in Chapter 3, Section 3.7.2.3.1 (Humpback 
Whale (Megaptera novaeangliae), Hawaii DPS) of the 2018 HSTT FEIS/OEIS, 
the best available science has demonstrated humpback whale population 
increases and an estimated abundance greater than some pre-whaling 
estimates. This data does not indicate any population-level impacts 
from decades of ongoing Navy training and testing in the Hawaiian 
Islands. The LFAS sources used in the HSTT Study Area are typically low 
powered (less than 200 dB source level). Restrictions on the use of 
LFAS would have a significant impact on the testing of current systems 
and the development of new systems. This would deny research, testing, 
and development program managers the flexibility to rapidly field or 
develop necessary systems requiring testing in the area and the ability 
to conduct these activities in the unique bathymetric environment of 
the 4-Islands Region.
    Comment 71: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended additional mitigation areas including critical 
habitat for the Main Hawaiian Islands insular false killer whale. NMFS 
issued the Final Rule designating critical habitat under the ESA on 
July 24, 2018. The Commenter stated that in light of the 2018 listing 
under the ESA, NMFS must protect this species from the noise and other 
disturbance resulting from naval activities, including by mitigating 
impacts within its critical habitat. The Commenter recommended that, at 
minimum, the Navy establish protective Mitigation Areas in all the BIAs 
identified for this species by NOAA and that NMFS should revisit and 
revise its Mitigation Areas and mitigation requirements based on the 
final critical habitat designation.
    Response: Critical habitat includes waters from the 45-m depth 
contour to the 3,200-m depth contour around the main Hawaiian Islands 
from Niihau east to Hawaii (82 FR 51186). With regard to the analysis 
of the identified Biologically Important Areas for the Main Hawaiian 
Islands insular false killer whales, see Section K.3.3 in the 2018 HSTT 
FEIS/OEIS (False Killer Whale Small and Resident Population Area: Main 
Hawaiian Island Insular stock), which NMFS used to support our analysis 
for the MMPA rule. With regard to the identified threats to the 
species, see Section 3.7.2.2.7.5 in the 2018 HSTT FEIS/OEIS (Species-
Specific Threats) and specifically the documented incidental take by 
commercial fisheries (Bradford and Forney, 2016; Oleson et al., 2010; 
Reeves et al., 2009; West, 2016).
    The Navy is implementing the Hawaii Island Mitigation Area which 
encompasses all of the BIA for Main Hawaiian Islands insular false 
killer whales around that island, and the 4-Islands Region Mitigation 
Area (which captures approximately 40 percent of the BIAs in the 4-
Islands area). As discussed in the Mitigation Areas in Hawaii section 
of the 2018 HSTT final rule, these mitigation areas are expected to 
significantly reduce impacts to this stock and its habitat. NMFS has 
determined that the Navy's current training and testing activities are 
not expected to have fitness consequences for individual Main Hawaiian 
Islands insular false killer whales and are not likely to reduce the 
viability of the populations those individual whales represent. Further 
limitation of activities in the area identified by the commenter would 
not be practicable and is not included as a measure.
    Comment 72: In a comment on the 2018 HSTT proposed rule, Commenters 
recommended additional mitigation areas for important habitat areas off 
Oahu, Kauai, and Niihau, providing mitigation measures for select 
activities during even a limited season within some important habitat 
areas. The waters off Oahu, Kauai, and Niihau include a number of 
important habitat areas for a variety of species, including false 
killer whale critical habitat (see above), five NOAA-identified BIAs 
off Oahu (false killer whale, humpback whale, pantropical spotted 
dolphin, bottlenose dolphin, and spinner dolphin) and three BIAs off 
Kauai and Niihau (humpback whale, spinner dolphin, and bottlenose 
dolphin) (Baird et al., 2012).
    Response: The 2018 HSTT FEIS/OEIS considered the science, the Navy 
requirements, and the mitigation value of identified habitat areas off 
Oahu, Kauai, and Niihau as presented in Appendix K (Geographic 
Mitigation Assessment) Section K.3 (Biologically Important Areas within 
the Hawaii Range Complex Portion of the HSTT Study Area), which NMFS 
used to support our analysis for the MMPA rule. This includes the five 
identified BIAs off Oahu (false killer whale, humpback whale, 
pantropical spotted dolphin, bottlenose dolphin, and spinner dolphin) 
and three BIAs off Kauai and Niihau (humpback whale, spinner dolphin, 
and bottlenose dolphin) as well as a discussion in Appendix K 
(Geographic Mitigation Assessment), Section K.1.1.5 (Mitigation Areas 
Currently Implemented) regarding the 4-Islands Region Mitigation Area. 
See aslo the discussion in Appendix K (Geographic Mitigation 
Assessment), Section K.2.1.2 (Biological Effectiveness

[[Page 41830]]

Assessment) of the 2018 HSTT FEIS/OEIS.
    The Mitigation Areas in Hawaii section of the 2018 HSTT final rule 
describes in detail the significant reduction of impacts afforded by 
the required 4-Islands Region Mitigation Area and Hawaii Island 
Mitigation Area to the species and stocks cited by the Commenters. 
Together, these two areas significantly reduce impacts in this 
important calving and breeding area for Humpback whales--please see the 
response to Comment 74 for additional details regarding why additional 
mitigation areas for humpback whales off Oahu, Niihua, or Kauai are not 
included. Further, the Hawaii Island Mitigation Area overlaps multiple 
small resident populations (BIAs) of odontocetes that span multiple 
islands, and this mitigation area overlaps all of the stock's range 
around the island of Hawaii for false killer whales (Main Hawaiian 
Island insular stock) and spinner dolphins (Hawaiian Islands stock), 
and approximately 90 percent of the range around the island of Hawaii 
for pantropical spotted dolphins (Hawaii stock). Additionally, critical 
habitat has been designated, pursuant to the ESA, for false killer 
whales (Main Hawaiian Island insular stock) in waters between 45 and 
3,200 m depth around all of the Main Hawaiian Islands, and this 
mitigation area captures more than 95 percent of this area around the 
island of Hawaii. The 4-Islands Region Mitigation Area also overlaps 
multiple small resident populations of marine mammals (BIAs) that span 
multiple islands, including about 80 percent of the pantropical spotted 
dolphin (Hawaii stock) area adjacent to these four islands (one of 
three discrete areas of the BIA), about 40 percent of the portion of 
the false killer whale's (Main Hawaiian Island insular stock) range 
that spans an area north of Molokai and Maui (one of the two 
significantly larger areas that comprise the false killer whale BIA), 
and a good portion of the BIA for spinner dolphins (Hawaiian Islands 
stock), which spans the Main Hawaiian Islands in one large continuous 
area. As noted above, the ESA-designated critical habitat for false 
killer whales extends fairly far offshore (to 3,200 m depth) around all 
the Main Hawaiian Islands. As described in the Hawaii Island Mitigation 
Area section noted above, by limiting exposure to the most impactful 
sonar source and explosives for these stocks in this 4-Islands Region 
Mitigation Area, in addition to the Hawaii Island Mitigation Area, both 
the magnitude and severity of both behavioral impacts and potential 
hearing impairment are greatly reduced. See the responses to comments 
71 and 64 for additional discussion of false killer whale mitigation.
    The Commenters cite concerns for population-level effects. As 
detailed in the 2018 HSTT FEIS/OEIS and indicated in this final rule, 
the planned Navy training and testing activities are not likely to 
result in impacts on reproduction or survival. There is no evidence to 
suggest there have been any population-level effects in the waters 
around Oahu, Kauai, and Niihau or in the HSTT Study Area resulting from 
the training and testing activities that have been ongoing for decades, 
which the Commenters recommend the need to stop, or at a minimum, be 
mitigated. In the waters around Oahu, Kauai, and Niihau, documented 
long-term residency by individuals and the existence of multiple small 
and resident populations precisely where Navy training and testing have 
been occurring for decades strongly suggests a lack of significant 
impact to those individuals and populations from the continuation of 
Navy training and testing. Appendix K of the 2018 HSTT FEIS/OEIS 
further describes the importance of these areas for Navy training and 
testing and why implementation of additional mitigation areas would be 
impracticable.
    Last, as discussed previously, the Navy adopted all mitigation 
measures that are practicable without jeopardizing its mission and 
Title 10 responsibilities. In other words, a comprehensive assessment 
by Navy leadership of the final, entire list of mitigation measures 
concluded that the inclusion of any further mitigation beyond those 
measures identified here in the final rule would be impracticable. NMFS 
independently reviewed the Navy's practicability determinations for 
specific mitigation areas and concurs with the Navy's analysis. Given 
the significant protection already afforded by the required measures, 
and the impracticability of further geographic restrictions, NMFS has 
determined that these measures are not warranted.
    Comment 73: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended an additional mitigation area for Cross Seamount, 
as Cross Seamount represents important foraging habitat for a 
potentially rare or evolutionary distinct species of beaked whale. The 
Commenter strongly recommended that the 2018 HSTT EIS/OEIS assess the 
designation of a year-round management area to protect the seamount. 
Such a designation would have secondary benefits for a variety of other 
odontocete species foraging at Cross Seamount seasonally between 
November and May. NMFS should also consider habitat-based management 
measures for other nearby seamounts.
    Response: NMFS and the Navy considered Cross Seamount and ``other 
nearby seamounts'' for additional geographic mitigation as described in 
Appendix K (Geographic Mitigation Assessment), Section K.7.1 (Hawaii 
Public Comment Mitigation Area Assessment), including sub-sections 
K.7.1.1 (General Biological Assessment of Seamounts in the Hawaii 
Portion of the Study Area) and K.7.1.2 (Cross Seamount) of the 2018 
HSTT FEIS/OEIS, which was used to support NMFS mitigation evaluation 
for this rule.
    As discussed in Appendix K (Geographic Mitigation Assessment), 
Section 4.7.1.3 (Mitigation Assessment) of the 2018 HSTT FEIS/OEIS, 
implementing new geographic mitigation measures in addition to ongoing 
procedural mitigation within the vicinity of Cross Seamount would not 
be effective at reducing adverse impacts on beaked whales or other 
marine mammal populations. The Navy has been training and testing in 
the broad ocean area around Cross Seamount with the same basic systems 
for over 40 years, and there is no evidence of any adverse impacts to 
marine species. Additionally, the suggested mitigation would not be 
practicable for the Navy to implement. The broad ocean area around 
Cross Seamount and the seamounts to the north are unique in that there 
are no similar broad ocean areas in the vicinity of the Hawaiian 
Islands that are not otherwise encumbered by commercial vessel traffic 
and commercial air traffic routes. In addition, beaked whales may be 
more widely distributed than currently believed. For example, Martin et 
al. (2019) detected Cross Seamount beaked whale vocalizations at PMRF. 
Ongoing passive acoustic efforts from NMFS and Navy within the Pacific 
have documented beaked whale detections at many locations beyond slopes 
and seamounts to include areas over abyssal plains (Klinck et al. 2015, 
Griffiths and Barlow 2016, Rice et al., 2018).
    Comment 74: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that NMFS must ensure that the activities are having 
the least practicable adverse impact, so it must do a comprehensive 
analysis of whether the proposed mitigation areas sufficiently protect 
marine mammals. They asserted that NMFS must require the Navy to 
implement additional, practicable measures to mitigate further the 
adverse impacts of its activities. To ensure least practicable adverse 
impacts, NMFS must consider additional mitigation

[[Page 41831]]

time/area restrictions, including but not limited to: (1) Expanded 
areas in Southern California to include all of the biologically 
important areas for whales; (2) add a Cuvier's beaked whale mitigation 
area in Southern California to protect that small, declining population 
that has high site fidelity; (3) add mitigation areas for the 
biologically important areas off of Oahu and Kauai; (4) the entire 
Humpback National Marine Sanctuary should be afforded protections from 
Navy activities because it is an important habitat for breeding, 
calving and nursing; and (5) limits on sonar and explosives should be 
adopted in the designated critical habitat for the Hawaiian monk seal 
and false killer whale.
    Response: In regard to expanded areas in Southern California to 
include all of the biologically important areas for whales, the Navy 
has agreed to expanded areas in SOCAL, a portion of the San Nicolas 
Island BIA and the Santa Monica/Long Beach BIA are now included as part 
of the San Diego Arc Mitigation Area but also named the San Nicolas 
Island Mitigation Area and the Santa Monica/Long Beach Mitigation Area. 
The Santa Monica Bay/Long Beach and San Nicolas Island BIA only 
partially overlaps a small portion of the northern part of the SOCAL 
portion of the HSTT Study Area. The Santa Monica Bay/Long Beach BIA 
overlap in SOCAL is 13.9 percent. The San Nicolas Island BIA overlap in 
SOCAL is 23.5 percent.
    The Navy will limit surface ship sonar and not exceed 200 hours of 
MFAS sensor MF1 June 1 through October 31 during unit-level training 
and MTEs in the Santa Monica Bay/Long Beach BIA and San Nicolas Island 
Mitigation Areas (as well as San Diego Arc Mitigation Area). The Navy 
has also agreed to limit explosives. Specifically, within the San 
Nicolas Island Mitigation Area, the Navy will not use explosives that 
could potentially result in the take of marine mammals during mine 
warfare, large-caliber gunnery, torpedo, bombing, and missile 
(including 2.75 in rockets) activities during training. Within the 
Santa Monica/Long Beach Mitigation Area, the Navy will not use 
explosives that could potentially result in the take of marine mammals 
during mine warfare, large-caliber gunnery, torpedo, bombing, and 
missile (including 2.75-in rockets) activities during training and 
testing.
    For the Tanner-Cortes Bank BIA, NMFS and the Navy have discussed 
this extensively, and the Navy is unable to incorporate this area into 
geographic mitigation because it is impracticable. Specifically, it 
would not be practical for the Navy to implement and would prevent the 
Navy from meeting training and testing missions. As discussed in detail 
in Appendix K (Geographic Mitigation Assessment) of the 2018 HSTT FEIS/
OEIS, during the Navy's practicability and biological review of the 
Tanner Bank BIA, it was concluded that implementation of a mitigation 
area was not practical for this species. The area in and around Tanner 
Banks is a core high priority training and testing venue for SOCAL 
combining unique bathymetry and existing infrastructure. This includes 
an existing bottom training minefield adjacent to Tanner Banks, future 
Shallow Water Training Range (SWTR West) expansion as well as proximity 
to critical tactical maneuver areas to the south and the Navy's 
underwater instrumented range to the northeast. Furthermore, the 
general area is in or adjacent to critical Navy training that cannot 
occur at other locations due to available, existing infrastructure, 
operationally relevant bathymetry, sea space, proximity to San Clemente 
Island and San Diego, etc. Of all the blue whale BIAs designated, the 
Tanner Banks BIA had the fewest blue whale sighting records supporting 
its designation. New science since designation funded by the Navy 
further highlights how infrequently Tanner Bank is used by blue whales 
as compared to the rest of their movements in SOCAL. Out of 73 blue 
whales tagged with satellite transmitters, only a few transits through 
Tanner Banks were documented between 2014 and 2017. The longest 
cumulative time any individual whale stayed within the boundaries of 
the Tanner Banks BIA was less than one-and-a-half days. Typical average 
blue whale daily movement along the U.S. West Coast is often up to 13-
27 nautical miles a day (Oregon State University, unpublished data). 
Most blue whale area restricted foraging occurred around the northern 
Channel Islands, north of and outside of the HSTT SOCAL Study Area.
    The feeding areas as recommended by the Commenter north of Los 
Angeles for humpbacks (Santa Barbara Channel--San Miguel BIA and Morro 
Bay to Pt Sal) and blue whales (Santa Barbara Channel to San Miguel 
BIA, Pt Conception/Arguello to Pt Sal) are outside of the HSTT Study 
Area; therefore, they are not applicable for inclusion.
    In regard to adding a Cuvier's beaked whale mitigation area in 
Southern California to protect that small, declining population that 
has high site fidelity, NMFS is assuming the Commenter is referring to 
the area west of San Clemente Island as the comment letter did not 
specify an exact location. The beaked whale species detected most 
frequently in Southern California is Cuvier's beaked whale. Cuvier's 
beaked whales are widely distributed within Southern California and 
across the Pacific with almost all suitable deep water habitat >800 m 
conceivably containing Cuvier's beaked whales. In new unpublished Navy 
funded data, beaked whales have even been detected over deep water, 
open abyssal plains (>14,000 ft). The Commenter's declining beaked 
whale statement does not fully represent the current state of the 
science. Moore and Barlow (2013) noted a decline in the overall beaked 
whale population in a broad area of the Pacific Ocean along the U.S. 
West Coast. New data has been published raising uncertainties over 
whether a decline in the beaked whale population occurred off the U.S. 
West Coast between 1996 and 2014 (Barlow, 2016). Moore and Barlow 
(2017) have since incorporated information from the entire 1991 to 2014 
time series, which suggests an increasing abundance trend and a 
reversal of the declining trend along the U.S. West Coast that had been 
noted in their previous (2013) analysis. Furthermore, there is no 
evidence of any declining beaked whale populations in Southern 
California. Schorr et al. (2020) and DiMarzio et al. (2020) continue to 
document repeated sightings of the same beaked whales and steady if not 
increasing population in SOAR. Only limited population vital rates 
exist for beaked whales, covering numbers of animals, populations vs. 
subpopulations determination, and residency time for individual 
animals. While Cuvier's beaked whales have been detected north and west 
of Tanner and Cortes Banks, as noted above this species is also 
detected in most all Southern California locations 800 m in depth. The 
Navy's Marine Mammal Monitoring on Navy Ranges (M3R) program has 
documented continual Cuvier's beaked whale presence on SOAR over ten 
years from 2010-2019 with slight abundance increases through 2019 
(DiMarzio et al., 2018, 2019, 2020).
    Navy-funded research on Cuvier's beaked whales within the SOCAL 
Range Complex began in 2006. In 2008, researchers began deploying 
satellite tags as a part of this research. To date, 27 Low-Impact 
Minimally-Percutaneous External-electronics Transmitting (LIMPET) tags 
have been deployed within the complex. Twenty-five of those whales were 
tagged within the San Nicolas Basin and two were tagged in the Catalina 
Basin. Average transmission duration was 36.6 days (sd

[[Page 41832]]

= 29.8), with the longest transmitting for 121.3 days. Movement data 
suggest that Cuvier's beaked whales have a high degree of site-fidelity 
to the Southern California Range Complex, and the San Nicolas basin in 
particular. Overall, there were 3,207 filtered location estimates from 
the 27 tagged whales, 91 percent of which were within the SoCal Range 
Complex. 54 percent of all location estimates were within the San 
Nicolas Basin, with twelve tagged whales spending more than 80 percent 
of their transmission duration within the basin. The two whales tagged 
in the Catalina Basin never entered the San Nicolas Basin. Only three 
whales tagged in the San Nicolas Basin crossed into the Catalina Basin 
(1.3 percent of all locations); two of those whales had just one 
Catalina Basin location each, though the remaining whale had 28 percent 
of its locations there. Five whales tagged in the San Nicolas Basin 
moved into the Santa Cruz Basin for anywhere from 1-62 percent of their 
time (6 percent of all locations). In contrast, 20 of 25 whales tagged 
in the San Nicolas Basin moved south of the basin at some point. Of 
these 20 whales, most remained within either Tanner Canyon or the San 
Clemente Basin immediately to the south, but one traveled north to near 
San Miguel Island and four traveled south towards Guadalupe Island. 
Three of these whales have not been documented in the San Nicolas basin 
since, though to date at least six whales tagged in the San Nicolas 
Basin have been re-sighted there a year or more after the deployment. 
Additionally, one of the whales that was south of San Nicolas when the 
tag stopped transmitting has since been sighted three times since.
    Given the uncertainty regarding residence of Cuvier's beaked whales 
in the areas north and west of SOAR, the fact that general occurrence 
of beaked whales in Southern California may not necessarily relate to 
factors typically associated with biologically important areas (i.e., 
one area not being more important than another), the likely increasing 
abundance trend in Cuvier's beaked whales in the area, and 
consideration of the importance of Navy training and testing in the 
areas around SOAR and Tanner and Cortes Banks (i.e., the 
impracticability of additional area mitigation in this area; see 
Appendix K (Geographic Mitigation Assessment)), additional geographic 
mitigation to create a ``refuge'' in the recommended area is not 
scientifically supported or warranted.
    In regard to the comment proposing that the entire Humpback Whale 
National Marine Sanctuary should be afforded protections from Navy 
activities because it is an important habitat for breeding, calving and 
nursing, the Humpback National Marine Sanctuary largely overlaps both 
the Hawaii Island Mitigation Area as well as the 4-Islands Region 
Mitigation Area. In the Hawaii Island Mitigation Area (year-round), the 
Navy will not conduct more than 300 hours of MF1 surface ship hull-
mounted mid-frequency active sonar or 20 hours of MF4 dipping sonar, or 
use explosives that could potentially result in takes of marine mammals 
during training and testing. In the 4-Islands Region Mitigation Area 
(November 15-April 15 for active sonar; year-round for explosives), the 
Navy will not use MF1 surface ship hull-mounted mid-frequency active 
sonar or explosives that could potentially result in takes of marine 
mammals during training and testing. This seasonal limitation is 
specifically during important breeding, calving, and nursing times/
habitat for humpback whales and was expanded for humpback whales as the 
previous season for this mitigation area was December 15-April 15.
    There are areas of the Humpback Whale National Marine Sanctuary 
around the islands of Niihau, Kauai, Oahu, and west of Molokai (Penguin 
Bank) that are outside of the Navy's mitigation areas. However, none of 
the Navy's training and testing areas for explosives around Kauai and 
Niihau are within the Hawaiian Islands Humpback Whale National Marine 
Sanctuary. There may be limited sonar use as units transit to/from PMRF 
ranges.
    Part of the Humpback Whale National Marine Sanctuary, west of the 
island of Molokai, Penguin Bank, is not included in the 4-Islands 
Region Mitigation Area. Penguin Bank particularly is used for shallow 
water submarine testing and anti-submarine warfare training because of 
its large expanse of shallow bathymetry. While submarines do not 
typically use mid-frequency active sonar, relying primarily on passive 
sonar (listening mode) to avoid detection from adversaries, submarines 
are required to train in counter detection tactics, techniques and 
procedures against threat surface vessels, airborne anti-submarine 
warfare units and other threat submarines using mid-frequency active 
sonar as part of both their perspective Commanding Officers 
qualification course and pre-deployment certification. The ability for 
surface vessels and air assets to simulate opposing forces, using mid-
frequency active sonar when training with submarines, is critical to 
submarine crew training for deployed and combat operations. Surface 
ships and aircraft mimicking opposition forces present submarines with 
a realistic and complicated acoustic and tactical environment. The Navy 
expects real-world adversaries to target our submarines with active 
sonar. Without active sonar from opposition forces, submarines do not 
get a realistic picture regarding if they successfully evaded 
detection. Surface warfare training is designed to support unit-level 
training requirements and group cross-platform events in 28 mission 
areas for surface ship certification prior to deployment.
    Additionally, the Navy will implement the Humpback Whale Special 
Reporting Area (December 15 through April 15), comprised of additional 
areas of high humpback whale densities that overlap the Humpback Whale 
National Marine Sanctuary. This reporting is included in the exercise 
and monitoring reports that are an ongoing Navy requirement and are 
submitted to NMFS annually. Special reporting data, along with all 
other reporting requirements, are considered during adaptive management 
to determine if additional mitigation may be required. The Navy 
currently reports to NMFS the total hours (from December 15 through 
April 15) of all hull-mounted mid-frequency active sonar usage 
occurring in the Humpback Whale Special Reporting Area, plus a 5 km 
buffer, but not including the Pacific Missile Range Facility. The Navy 
will continue this reporting for the Humpback Whale Special Reporting 
Area.
    In regard to the comment that limits on sonar and explosives should 
be adopted in the ESA-designated critical habitat for the Hawaiian monk 
seal and false killer whale, the Navy will cap MFAS for the entire 
false killer whale BIA adjacent to the island of Hawaii and a portion 
of the false killer whale BIA north of Maui and Molokai as follows. The 
Navy already will limit explosive use in the entire false killer whale 
BIA adjacent to the island of Hawaii. Per the 2018 HSTT final rule, the 
Navy currently implements year-round limitation on explosives to the 4-
Islands Region Mitigation Area, which includes a portion of the false 
killer whale BIA north of Maui and Molokai.
    For the Hawaii Island Mitigation Area (year-round): The Navy will 
not conduct more than 300 hours of surface ship hull-mounted MFAS sonar 
MF1 (MF1) or 20 hours of MFAS dipping sonar MF4 (MF4), or use 
explosives during training and testing year-round.
    For the 4-Islands Region Mitigation Area (November 15-April 15 for 
active sonar, year-round for explosives): The

[[Page 41833]]

Navy will not use surface ship hull-mounted MFAS sonar MF1 from 
November 15-April 15 and explosives year-round during training or 
testing activities. The remaining false killer whale BIA overlaps with 
areas (e.g., Kaiwi Channel) where additional mitigations were found to 
be impractical.
    In regard to limits on sonar and explosives in ESA-designated 
critical habitat for Hawaiian monk seal, the Navy's training and 
testing activities do occur in a portion of the ESA-designated critical 
habitat for Hawaiian monk seals, which is of specific importance to the 
species. However, monk seals in the main Hawaiian Islands have 
increased while the Navy has continued its activities, even though the 
Hawaiian monk seal overall population trend has been on a decline from 
2004 through 2013, with the total number of Hawaiian monk seals 
decreasing by 3.4 percent per year (Carretta et al., 2017). While the 
decline has been driven by the population segment in the northwestern 
Hawaiian Islands, the number of documented sightings and annual births 
in the main Hawaiian Islands has increased since the mid-1990s (Baker, 
2004; Baker et al., 2016). In the main Hawaiian Islands, the estimated 
population growth rate is 6.5 percent per year (Baker et al., 2011; 
Carretta et al., 2017). Of note, in the 2013 HRC Monitoring Report, 
tagged monk seals did not show any behavioral changes during periods of 
MFAS.
    The Hawaii Island Mitigation Area overlaps all of their critical 
habitat around the Island of Hawaii (as well as the southern end of 
Maui) and, by not using explosives or the most impactful sonar sources 
in this, thereby reduces the likelihood that take might impact 
reproduction or survival by interfering with important feeding or 
resting behaviors (potentially having adverse impacts on energy 
budgets) or separating mothers and pups in times when pups are more 
susceptible to predation and less able to feed or otherwise take care 
of themselves. The 4-Islands Mitigation Area overlaps with ESA-
designated critical habitat around Maui, Lanai, and Molokai.
    Comment 75: In a comment on the 2018 HSTT proposed rule, a 
Commenter noted that in the 2018 HSTT proposed rule, NMFS estimates 588 
takes annually will cause multiple instances of exposure to insular 
false killer whales, taking 400 percent of the population. As the 
potential biological removal (PBR) is 0.18 animals, the loss of a 
single individual, or an impairment to its health and fitness, could 
place the species on an extinction trajectory. The Commenter asserted 
NMFS must consider additional mitigation in the designated critical 
habitat, as well as excluded areas, to ensure a negligible impact on 
false killer whales.
    Response: The Commenter is conflating expected numbers of Level B 
behavioral harassment take with the PBR number presented in the SAR. 
There are no insular false killer whale mortality takes modeled, 
anticipated, or authorized. Four hundred percent of the population 
would mean that all animals would be behaviorally harassed an average 
of four times per year, or once per season. The short term biological 
reaction of an animal for periods of minutes to hours a few times a 
year would not have any fitness impacts to the individual let alone any 
population level impacts. NMFS confirms that these impacts are 
negligible. Additionally, much of the Navy's mitigations on Hawaii and 
the 4 islands region encompass areas that overlap with high use insular 
false killer whale habitat and thus already mitigate impacts. From the 
Navy consultation with NMFS under the ESA for insular false killer 
whale critical habitat, less than 12 percent of modeled takes would 
take place in or near insular false killer whale critical habitat. 
These takes as explained previously would be transitory (short-
duration), and spread out in time and space.
    Comment 76: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended establishing stand-off distances around the 
Navy's mitigation areas to the greatest extent practicable, allowing 
for variability in size given the location of the area, the type of 
operation at issue, and the species of concern.
    Response: Mitigation areas are typically developed in consideration 
of both the area that is being protected and the distance from the 
stressor in question that is appropriate to maintain to ensure the 
protection. Sometimes this results in the identification of the area 
plus a buffer, and sometimes both the protected area and the buffer are 
considered together in the designation of the edge of the area. We note 
that the edges of a protected area are typically of less importance to 
a protected stock or behavior, since important areas often have a 
density gradient that lessens towards the edge. Also, while a buffer of 
a certain size may be ideal to alleviate all impacts of concern, a 
lessened buffer does not mean that the protective value is 
significantly reduced, as the core of the area is still protected. 
Also, one should not assume that activities are constantly occurring in 
the area immediately adjacent to the protected area.
    These issues were considered here, and the Navy has indicated that 
the mitigation included in the final rule represents the maximum 
mitigation within mitigation areas and the maximum size of mitigation 
areas that are practicable to implement under the specified activities. 
The Navy has communicated (and NMFS concurs with the assessment) that 
implementing additional mitigation (e.g., stand-off distances that 
would extend the size of the mitigation areas) beyond what is described 
here would be impracticable due to implications for safety (the ability 
to avoid potential hazards), sustainability (based on the amount and 
type of resources available, such as funding, personnel, and 
equipment), and the Navy's ability to continue meeting its Title 10 
requirements.
    Comment 77: In a comment on the 2019 HSTT proposed rule, Commenters 
noted that Southall et al. (2019c) investigated Cuvier's beaked whale 
prey dynamics on SOAR and found that Cuvier's beaked whales, as well as 
their prey, were concentrated on the western side of SOAR. They stated 
that if beaked whales were to leave their preferred habitat on SOAR due 
to disturbance, Southall et al. (2019c) stipulated that the animals 
could encounter both the energetic costs of moving and substantially 
poorer foraging options in the alternative areas (both offshore of SOAR 
and on the eastern side of SOAR). Given the very large differences in 
prey quality measured between those areas, the researchers asserted 
that it may prove challenging for individual beaked whales to meet 
basic energetic requirements in some of those areas, which could have 
population-level consequences (Southall et al. 2019c). The Commenters 
note that it is unclear the timescale over which the prey surveys were 
conducted by Southall et al. (2019) and whether the prey dynamics were 
reflective of seasonal or year-round patterns. However, they noted that 
the researchers' contention that mitigation measures that would 
concentrate MFA sonar operations to the eastern rather than western 
side of SOAR would be beneficial for reducing the potential 
consequences of disturbance, particularly for those operations that use 
higher-intensity sonar. Commenters asserted that the findings of 
Southall et al. (2019c) suggest that the off-range refuge areas 
established by consent order in Conservation Council for Hawaii v. 
NMFS, while presenting foraging habitat that is superior to that on the 
eastern side of the range, are markedly inferior

[[Page 41834]]

to the whales' preferred foraging habitat on the western side. 
Commenters recommended NMFS investigate whether the findings of 
Southall et al. (2019) are applicable to seasonal or year-round 
conditions at SOAR and whether implementation of mitigation areas on 
the western side of SOAR would be a prudent approach for meeting its 
negligible impact and least practicable adverse impact determinations 
under the MMPA.
    Response: Prey data analyzed by Southall et al. (2019c) were 
published in Benoit-Bird et al. (2016) and collected in 2013. The field 
effort only encompassed four days of survey in September 2013 to 
include five transits in Western SOAR, five transits in eastern SOAR, 
and two transits off-range. Southern, western, and eastern SOAR, areas 
also used by beaked whales as shown by satellite tracking, were not 
surveyed. Furthermore, based on passive acoustic monitoring from two 
different sensor types, there is a repeated dip in Southern California 
beaked whale occurrence in the August and September timeframes. 
Therefore, there appears to be a factor, such as oceanography, prey 
availability, or other biological parameter from August to September 
that influences beaked whale occurrence unrelated to Navy activities. 
Given ocean basin level oceanographic fluctuations since 2013, it is 
also unclear if the 2013 prey results from Benoit-Bird et al. (2016) 
remain unchanged as of 2019. Recent research has also suggested that 
Cuvier's beaked whales tend to be visually sighted and passively 
acoustically detected more frequently in the western portion of SOAR 
(DiMarzio et al., 2020, Schorr et al., 2020). An important fact remains 
that cumulatively throughout the entire year, beaked whale occurrence 
and overall population abundance remains consistently stable in a 
heavily used training area as discussed previously (DiMarzio et al., 
2020; Schorr et al., 2020). Given the parameters of Southall et al. 
(2019) and Benoit-Bird et al. (2016) which include short-term seasonal 
sampling and limited sampling throughout SOAR, as well as potential 
variations in oceanographic parameters, it is premature and speculative 
to designate additional mitigation areas specifically for western SOAR. 
Also, current and ongoing beaked whale research on SOAR appears to 
demonstrate a stable beaked whale population using SOAR (DiMarzio et 
al., 2020; Schorr et al., 2020). Further, as noted in Appendix K 
(Geographic Mitigation Assessment) of the 2018 HSTT FEIS/OEIS, the 
waters in SOAR are critical to the Navy's training and testing 
activities and it is not practicable to preclude activities within that 
water space. Given the lack of sufficient evidence to support the 
specific significance of the western side of SOAR and the stability of 
beaked whale populations across SOAR, which suggests that Navy training 
and testing activities are not having significant impacts to the 
population of beaked whales anywhere in SOAR (DiMarzio et al., 2020, 
Schorr et al., 2020), and in consideration of the importance of Navy 
training and testing activities in this area discussed in Appendix K 
(Geographic Mitigation Assessment) of the 2018 HSTT FEIS/OEIS, 
additional geographic mitigation specifically for SOAR is not 
warranted.
    Comment 78: In a comment on the 2019 HSTT proposed rule, Commenters 
stated that the California (or Eastern North Pacific) gray whale is 
presently experiencing a major die-off which was declared an Unusual 
Mortality Event (UME). They asserted that it is well established that 
animals already exposed to one stressor may be less capable of 
responding successfully to another, and that stressors can combine to 
produce adverse synergistic effects (Wright et al., 2007). They noted 
that disruption in gray whale behavior can act adversely with the 
inanition caused by lack of food, increasing the risk of stranding and 
lowering the risk of survival in compromised animals. The Commenters 
further asserted that starving gray whales may travel into unexpected 
areas in search of food--a likely contributing cause of some of the 
ship-strikes observed in recently stranded animals.
    Due to the circumstances for gray whales, the Commenters 
recommended that NMFS strengthen the geographic protections proposed by 
the Navy to reduce activities in habitat used seasonally by gray 
whales. They noted that new scientific information on spatial and 
temporal interannual changes in the eastern North Pacific gray whale 
migration across seven migration seasons (2008-2009 to 2014-2015) 
indicates that an increasing proportion of the population is using the 
nearshore migration corridor in the Southern California Bight, 
especially near Los Angeles (Guazzo et al., 2019). In addition, the 
time period over which gray whales are detected visually off Los 
Angeles, and acoustically across the broader region, is extending into 
April (for acoustic detections) and May (for visual observations) 
(Guazzo et al., 2019). The Commenters strongly recommended that a 
Mitigation Area excluding sonar and explosives activities be 
established in, at minimum, the Gray Whale Awareness Notification 
Message Area, and that the mitigation period be extended from November-
March (the current period of operations for the Message Area) to 
November-May.
    Response: The Gray Whale Awareness Notification Message Area 
includes all waters in the SOCAL portion of the HSTT Study Area. As 
discussed in Appendix K (Geographic Mitigation Assessment Section K4.2) 
of the 2018 HSTT FEIS/OEIS, the gray whale migration BIA overlaps with 
a significant portion of the SOCAL portion of the HSTT Study Area out 
to 100 nmi from shore over 10 months of the year. There is no 
indication that infrequent behavioral disruptions from Navy activities 
interrupt or significantly delay transit, and gray whales are not 
anticipated to be foraging in this area. Therefore, creating a new 
mitigation area excluding sonar and explosive activities for the SOCAL 
portion of the HSTT Study Area is not warranted. The Navy's current 
awareness notification message includes information that gray whales 
may be present in the SOCAL portion of the HSTT Study Area from mid-
October through mid-July every year, which includes the November-May 
timeframe suggested by the Commenters.
    Comment 79: In a comment on the 2019 HSTT proposed rule, Commenters 
noted that long-term passive acoustic monitoring conducted in the 
Navy's SOCAL Range Complex from January 2013 to January 2017 detected a 
peak in Northeast Pacific blue whale B calls from summer through late 
winter with a peak from September through December, and a peak in 
Northeast Pacific blue whale D calls in May and June (Baumann-Pickering 
et al., 2018; Rice et al., 2017). They further asserted that the fall 
peak in blue whale vocalizations coincides with a peak in detections of 
mid-frequency active sonar in September through November. Resulting 
maximum cumulative sound exposure levels of wave trains during these 
times were greater than 170 dB re: 1 [mu]Pa2 -s, and the majority of 
mid-frequency active sonar wave trains occurred in November 2016 during 
a major training exercise (Rice et al., 2017). Explosions (including 
those associated with Naval training exercises and fishing activity) 
occurred relatively constantly throughout the monitoring period at the 
sites where Northeast Pacific blue whale vocalizations were detected 
most frequently (Rice et al., 2017). The Commenters asserted that this 
new information demonstrates a peak in Northeast Pacific blue whale

[[Page 41835]]

presence in the late fall, a time that has historically coincided with 
heightened periods of MFA sonar deployment and explosives use. The 
Commenters recommended that the seasonality of the San Diego Arc 
Mitigation Area and the Blue Whale Awareness Notification Message Area 
be extended from June-October to May-December, and again urge the Navy 
to strengthen its restrictions on activities during this period.
    Response: Rice et al. 2020 (the most recent report referenced by 
the Commenters was Rice et al. 2017) reports on Navy supported 
monitoring at various locations within the Southern California Range 
Complex portion of the HSTT Study Area. While the blue whale switch 
from D calls to B calls has been documented by Rice et al. 2018 and 
others, call detection may not be representative of the total blue 
whale population or relative proportion in the SOCAL area. Nor do the 
call data collected by offshore passive acoustic devices necessarily 
reflect the amount of time or number of animals that would be in the 
San Diego Arc Mitigation Area. For example, over four years of blue 
whale tagging in SOCAL, most whales with long-term satellite tracking 
tags typically have begun their southern migration by October (Mate et 
al. 2018). The amount of time blue whales spent in the San Diego Arc as 
a proportion of the total tag attachment time was very small. Based on 
90 blue whales tagged from 2014-2017, blue whales spent an average 
total of 1.2 days in the San Diego Mitigation Area (1.5 days 2014, 1.0 
days 2015, 0 days 2016, 0.3 days 2017) (Mate et al., 2018). 
Furthermore, the Navy reports that MTEs and unit level training spread 
throughout the year. There is no basis for the Commenters' statement of 
heightened sonar and explosive use in the fall. Rice et al. (2017) 
captured a MTE in November in one year's data at one of the recording 
sites (Site N). Site N is where trains with cSELs >170 dB were observed 
(not the other sites in Rice et al. 2017), however, Site N is not near 
the San Diego Arc Mitigation Area--it is south of San Clemente Island. 
Therefore, extending the timeframe of these mitigation areas is not 
warranted.
    Comment 80: In a comment on the 2019 HSTT proposed rule, Commenters 
stated that the least practicable adverse impact requirement imposes a 
``stringent standard'' on NMFS to ensure that marine mammals are 
protected to the greatest extent practical without interfering with 
military readiness. The Commenters noted that the Navy's agreement to 
restrict the use of sonar and explosives in specified habitat areas 
around the Hawaiian Islands and off Southern California demonstrates 
the practicability of implementing those specific time/area 
restrictions. The Navy implemented these measures for over three years 
during which time it never invoked its right under the settlement 
agreement to train in these areas if necessary for national security. 
The Commenters asserted that the Navy has a heavy burden to show these 
areas are now required for training and testing activities when it 
successfully maintained military readiness subject to the settlement 
agreement restrictions for over three years and that NMFS has not held 
the Navy to its burden.
    The Commenters note that of particular concern are areas to the 
northeast and southeast of Moloka`i leading into the Ka`iwi Channel as 
this area includes biologically important areas (BIAs) for the humpback 
whale, the Main Hawaiian Island Insular (MHI) stock of false killer 
whales, and spinner dolphins. This area was partially protected as part 
of settlement areas 2A, 2C, and 2D, all of which included a year-round 
ban on the use of explosives, as well as a prohibition on use of mid-
frequency active sonar during multi-unit training exercises (areas 2A 
and 2C). They asserted that the 2018 HSTT final rule and the proposed 
extension rule provide no protections for the BIAs located to the 
northeast and southeast of Moloka`i. They noted that the Navy admits 
that the primary use of the northeast Ka`iwi Channel is for transit, 
and some limited unit-level straits training when ships are transiting 
through the area, however, straits training is primarily conducted in 
the `Alenuih[amacr]h[amacr] channel and the Pailolo and Kalohi 
channels. The Commenters asserted that the inconvenience associated 
with longer transit times around northeast Moloka`i and Ka`iwi Channel 
which the Navy invoked to explain the alleged impracticability of 
additional protections for this area does not meet the ``stringent 
standard'' test imposed by courts. The Commenters also noted that the 
Penguin Bank training area, which is located wholly in previous 
settlement area 2A and to the southeast of Moloka`i, is used for 
specific submarine training and testing activities identified by the 
Navy. However, the Navy proffers no explanation why sonar and explosive 
restriction cannot be imposed for a limited five-month period annually, 
as in the rest of the 4-Islands Region Mitigation Area, leaving the 
remaining seven months free for military readiness activities. The 
Commenters noted that an increased reporting burden is exactly the type 
of inconvenience that the Court considered insufficient to meet the 
stringent practicability standard during the last round of HSTT 
authorizations. They asserted that NMFS cannot simply ``summarize the 
Navy's indication of impracticality without analyzing it all,'' but 
that is exactly what it has done here. The Commenters state that NMFS 
should reinstate additional protections around eastern Moloka`i and 
other biologically important marine habitat included in the 2015 
settlement agreement, and expand protections throughout the Ka`iwi 
Channel area as described above.
    Response: Appendix K (Geographic Mitigation Assessment) of the 2018 
HSTT FEIS/OEIS described the comprehensive method for analyzing 
potential geographic mitigation that included consideration of both a 
biological assessment of how the potential time/area limitation would 
benefit the species or stock 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 (e.g., including an assessment of the specific 
importance of that area for training, considering proximity to training 
ranges and emergency landing fields and other issues). The analysis 
included an extensive list of areas, including areas in which certain 
Navy activities were limited under the terms of the 2015 HSTT 
settlement agreement, areas identified by the California Coastal 
Commission, and areas suggested during scoping. As discussed in the 
2018 HSTT final rule and applicable to this rule, NMFS also 
specifically considered the measures from the 2015 settlement agreement 
and how they compared to both new procedural mitigation measures and 
mitigation areas (see the section Brief Comparison of 2015 Settlement 
Mitigation and Final HSTT Mitigation in the Rule in the 2018 HSTT final 
rule). For those areas that were previously covered under the 2015 
settlement agreement, 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

[[Page 41836]]

restrictions were practicable to implement over the longer term. The 
2018 HSTT final rule then provided the rationale, again applicable to 
this final rule, for not adopting the relatively small subset of 
measures that were not carried forward (i.e., why some areas from the 
2015 settlement agreement were fully or partially retained, and others 
were not, based upon the standards of the MMPA).
    As explained in more detail in the 2018 HSTT final rule and in the 
full analysis in Section 3 of Appendix K (Geographic Mitigation 
Assessment) of the 2018 HSTT FEIS/OEIS, Penguin Bank offers critical 
shallow and constrained conditions for Navy training (especially 
submarines) that are not available anywhere else in Hawaii. The areas 
north of Molokai and Maui that are not included in the current 4-
Islands Mitigation Area are similarly critical for certain exercises 
that specifically include torpedo exercises, deliberately conducted in 
this area north of the islands to avoid the other suitable training 
areas between the four islands where humpback whale density is higher. 
The 2015 settlement agreement mitigation restricted all MFAS and 
explosive use on Penguin Bank (area 2-A), however, as the Navy 
explained, this MFAS restriction is impracticable for the period 
covered by this rule because it would have unacceptable impacts on 
their training and testing capabilities. In addition, the Navy does not 
typically use explosives in this area. For the settlement areas north 
of Molokai and Maui that are not covered in the rule (area 2-B and part 
of area 2-C), the settlement agreement restricted explosive use but did 
not restrict MFAS in the 2-B area. Explosive use in these areas is also 
already rare, but for the reasons described in Appendix K of the 2018 
HSTT FEIS/OEIS, restricting MFAS use is impracticable and would have 
unacceptable impacts on training and testing. We also note that while 
it is not practicable to restrict MFAS use on Penguin Bank, MFAS use is 
relatively low and we have identified it as a special reporting area 
for which the Navy reports the MFAS use in that area to inform adaptive 
management discussions in the future. Additionally, some of the areas 
that the 2015 settlement agreement identified included language 
regarding extra vigilance intended to avoid vessel strikes. Neither 
NMFS nor the Navy thought that inclusion of this term as written would 
necessarily reduce the probability of a vessel strike, so instead we 
have included the Humpback Whale Awareness Notification provision, 
which sends out a message to all Navy vessels in Hawaii during the time 
that humpback whales are present. Last, we note that the 2015 
settlement mitigation areas with MFAS restrictions sometimes excluded 
all MFAS, while sometimes they limited the number of MTEs that could 
occur (with no limit on any particular type of sonar, meaning that 
hull-mounted surface ship sonar could be operated), whereas the sonar 
restrictions in this final rule limit the use of surface ship hull-
mounted sonar, which is the source that results in the vast majority of 
incidental takes.
Additional Mitigation Research
    Comment 81: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended NMFS consider additional mitigation measures to 
prescribe or research including: (1) Research into sonar signal 
modifications; (2) mitigation and research on Navy ship speeds (the 
Commenter recommended that the agency require the Navy to collect and 
report data on ship speed as part of the EIS process); and (3) 
compensatory mitigation for the adverse impacts of the activities on 
marine mammals and their habitat that cannot be prevented or mitigated.
    Response: NMFS consulted with the Navy regarding potential research 
into additional mitigation measures and discussion is included below.
    1. Research into sonar signal modification--Sonar signals are 
designed explicitly to provide optimum performance at detecting 
underwater objects (e.g., submarines) in a variety of acoustic 
environments. The Navy acknowledges that there is very limited data, 
and some suggest that up or down sweeps of the sonar signal may result 
in different animal reactions; however, this is a very small data 
sample, and this science requires further development. If future 
studies indicate this could be an effective approach, then NMFS and the 
Navy will investigate the feasibility and practicability to modify 
signals, based on tactical considerations and cost, to determine how it 
will affect the sonar's performance.
    2. Mitigation and research on Navy ship speeds inclusive of Navy 
collecting and reporting data on ship speed as part of the EIS--The 
Navy conducted an operational analysis of potential mitigation areas 
throughout the entire Study Area to consider a wide range of mitigation 
options, including but not limited to vessel speed restrictions. As 
discussed in Chapter 3, Section 3.0.3.3.4.1 (Vessels and In-Water 
Devices) of the HSTT FEIS/OEIS, Navy ships transit at speeds that are 
optimal for fuel conservation or to meet operational requirements. 
Operational input indicated that implementing additional vessel speed 
restrictions beyond what is identified in Chapter 5 (Mitigation), 
Section 5.4 (Mitigation Areas to be Implemented) of the 2018 HSTT FEIS/
OEIS would be impracticable to implement due to implications for safety 
and sustainability. In its assessment of potential mitigation, the Navy 
considered implementing additional vessel speed restrictions (e.g., 
expanding the 10 kn restriction to other activities). The Navy 
determined that implementing additional vessel speed restrictions 
beyond what is described in Chapter 5 (Mitigation), Section 5.5.2.2 
(Restricting Vessel Speed) of the 2018 HSTT FEIS/OEIS 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. Additionally, as described in 
Chapter 5 (Mitigation), Section 5.5.2.2 (Restricting Vessel Speed) of 
the HSTT FEIS/OEIS, any additional vessel speed restrictions would 
prevent vessel operators from gaining skill proficiency, would prevent 
the Navy from properly testing vessel capabilities, 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 this information and determined that additional 
vessel speed restrictions would be impracticable. As discussed in 
Chapter 5 (Mitigation), Section 5.3.4.1 (Vessel Movement) of the HSTT 
FEIS/OEIS, the Navy implements mitigation to avoid vessel strikes 
throughout the Study Area. As directed by the Chief of Naval Operations 
Instruction (OPNAVINST) 5090.1D, Environmental Readiness Program and as 
discussed in this rule and the 2018 HSTT final rule, Navy vessels 
report all marine mammal incidents worldwide, including ship speed. 
Therefore, the data required for ship strike analysis discussed in the 
comment is already being collected. Any additional data collection 
required would create an unnecessary and impracticable administrative 
burden on the Navy.
    3. Compensatory mitigation--For years, the Navy has implemented a 
very broad and comprehensive range of measures to mitigate potential 
impacts to marine mammals from military

[[Page 41837]]

readiness activities. As described in this rule, the 2018 HSTT final 
rule, and the 2018 HSTT FEIS/OEIS documents in Chapter 5 (Mitigation), 
NMFS and the Navy have expanded these measures further where 
practicable. Aside from direct mitigation, as noted by the Commenter, 
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 
Chapter 3, Section 3.0.1.1 (Marine Species Monitoring and Research 
Programs) of the HSTT FEIS/OEIS, the Navy provides extensive investment 
for research programs in basic and applied research. The U.S. 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. Compensatory mitigation 
is not required to be imposed upon LOA holders under the MMPA. 
Importantly, the Commenter did not recommend any specific measure(s), 
rendering it impossible to conduct any meaningful evaluation of its 
recommendation. Finally, many of the methods of compensatory mitigation 
that have proven successful in terrestrial settings (purchasing or 
preserving land with important habitat, improving habitat through 
plantings, etc.) are not applicable in a marine setting with such far-
ranging species. Thus, any presumed conservation value from such an 
idea would be purely speculative at this time.
    Comment 82: In a comment on the 2019 HSTT proposed rule, Commenters 
asserted that NMFS should consider source-based approaches to mitigate 
impacts on frequently exposed populations. They stated that several 
recent studies (described in their comments on the 2018 HSTT proposed 
rule) suggest that modifying the sonar signal might reduce behavioral 
response in at least some species of marine mammals, and certain 
promising types of modifications, such as converting upsweeps to 
downsweeps--which would not alter the signal's spectral output in any 
way--may well be practicable and should be studied further, especially 
for reducing impacts in cases where spatial conflicts are unavoidable.
    Response: As described in the 2018 HSTT final rule, sonar signals 
are designed explicitly to provide optimum performance at detecting 
underwater objects (e.g., submarines) in a variety of acoustic 
environments. NMFS and the Navy acknowledge that there is very limited 
data available on behavioral responses to modified sonar signals, and 
some suggest that up or down sweeps of the sonar signal may result in 
different animal reactions; however, this science requires further 
development. Further, the references cited by the Commenter pertain to 
harbor porpoises and harbor seals. Harbor porpoises are not found in 
the HSTT Study Area. The reaction of these two more coastal species may 
not be indicative of how all other species may react to the same 
stimuli. The Navy's research programs continue to support new hearing 
and response studies and results of these studies will be incorporated 
into future analyses. If future studies indicate this could be an 
effective approach, then NMFS and the Navy will investigate the 
feasibility and practicability to modify signals, based on tactical 
considerations and cost, to determine how it will affect the sonar's 
performance.
    Comment 83: In a comment on the 2019 HSTT proposed rule, Commenters 
asserted that NMFS should require the Navy, through the Center for 
Naval Analyses or a similar organization, to study whether active sonar 
activities in the HSTT Study Area can be reduced through the use of 
simulators.
    Response: The Navy has extensively studied and evaluated the degree 
to which simulations can be utilized to meet their mission 
requirements, and NMFS and the Navy have further considered the 
information in the context of measures that could potentially reduce 
impacts to marine mammals. We disagree that NMFS should require 
additional study.
    As described by the Navy, it already uses simulators, and the 
proposed activities were specifically built with the assumption that a 
certain percentage of training activities would be accomplished through 
simulation versus live training. The Navy currently uses, and will 
continue to use, computer simulation to augment training whenever 
possible. Simulators and synthetic training are critical elements that 
provide early skill repetition and enhance teamwork; however, they 
cannot duplicate the complexity faced by Navy personnel during military 
missions and combat operations for the types of active sonar used for 
the proposed activities (e.g., hull-mounted mid-frequency active 
sonar). Simulators are used at unit-level training for basic system 
familiarity and refresher training. In addition, several annual 
exercises in the Pacific Ocean, simulating many hundreds of hours of 
sonar use are conducted virtually for command staff training.
    As described in Chapter 5 (Mitigation) of the 2018 HSTT FEIS/OEIS, 
the Navy needs to train and test in the conditions in which it fights--
and these types of modifications would fundamentally change the 
activity in a manner that would not support the purpose and need for 
the training and testing (i.e., are entirely impracticable). NMFS finds 
the Navy's explanation for why adoption of these recommendations would 
unacceptably undermine the purpose of the testing and training 
persuasive. As described in the Mitigation Measures section of the 2018 
HSTT final rule, after independent review, NMFS finds Navy's judgment 
on the impacts of potential mitigation measures, including simulators, 
to personnel safety, practicality of implementation, and the 
undermining of the effectiveness of training and testing persuasive.
    Comment 84: In a comment on the 2019 HSTT proposed rule, due to the 
circumstances for gray whales (described in Comment 78) Commenters 
recommended that consistent with its responsibilities under the MMPA's 
provisions on UMEs (e.g., 16 U.S.C. 1421c), as well as with the 
requirements under NEPA to obtain information essential to its analysis 
of reasonable alternatives (40 CFR 1502.22), that NMFS urgently fund 
research to assess the extent of prey availability loss for California 
gray whales and to determine the cause of that loss of prey.
    Response: Since January 1, 2019, elevated gray whale strandings 
have occurred along the west coast of North America, from Mexico to 
Canada. This event has been declared an Unusual Mortality Event (UME). 
As part of the UME investigation process, NOAA has assembled an 
independent team of scientists to coordinate with the Working Group on 
Marine Mammal Unusual Mortality Events to review the data collected, 
sample stranded whales, and determine the next steps for the 
investigation. The investigative team has not as of yet identified a 
primary cause for the UME. The team is investigating various causes 
that could

[[Page 41838]]

be contributing to the increased strandings including disease, 
biotoxins, human interactions, environmental drivers, carrying 
capacity, etc. For the environmental and oceanographic impacts, the 
team is working with (and in part, financially supporting) a subgroup 
of researchers (both internal and external to NMFS) that are currently 
researching changes in oceanographic temperatures, primary 
productivity, and prey impacts (and other indicators) during the UME to 
help us understand what if any environmental drivers may be impacting 
the whales.
    Comment 85: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that given the paucity of information on marine 
mammal habitat currently available for the HSTT Study Area, efforts 
should be undertaken in an iterative manner by NMFS, and the Navy, to 
identify additional important habitat areas across the HSTT Study Area, 
using the full range of data and information available to the agencies 
(e.g., habitat-based density models, NOAA-recognized BIAs, survey data, 
oceanographic and other environmental data, etc.).
    Response: NMFS and the Navy used the best available scientific 
information (e.g., SARs and numerous study reports from Navy-funded 
monitoring and research in the specific geographic region) in assessing 
density, distribution, and other information regarding marine mammal 
use of habitats in the HSTT Study Area. In addition, NMFS consulted 
LaBrecque et al. (2015), which provides a specific, detailed assessment 
of known BIAs. These BIAs may be region-, species-, and/or time-
specific, include reproductive areas, feeding areas, migratory 
corridors, and areas in which small and resident populations are 
concentrated. While the science of marine mammal occurrence, 
distribution, and density resides as a core NMFS mission, the Navy does 
provide extensive support to the NMFS mission via ongoing HSTT specific 
monitoring as detailed in this final rule. The Navy also provides 
funding support to NMFS for programmatic marine mammal surveys in 
Hawaii and the U.S. West Coast, and spatial habitat model improvements. 
NMFS and the Navy in collaboration with experts are currently working 
to assess and update current BIAs, and identify new BIAs for marine 
mammals.
    Comment 86: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended integration of important habitat areas to improve 
resolution of operations. The delineation of BIAs by NOAA, the updates 
made by the Navy to its predictive habitat models, and evidence of 
additional important habitat areas within the HSTT Study Area provide 
the opportunity for the agencies to improve upon their current approach 
to the development of alternatives by improving resolution of their 
analysis of operations. The Commenter offered the following thoughts 
for consideration.
    They state that recognizing that important habitat areas imply the 
non-random distribution and density of marine mammals in space and 
time, both the spatial location and the timing of training and testing 
events in relation to those areas is a significant determining factor 
in the assessment of acoustic impacts. Levels of acoustic impact 
derived from the NAEMO model are likely to be under- or over-estimated 
depending on whether the location of the modeled event is further from 
the important habitat area, or closer to it, than the actual event. 
Thus, there is a need for the Navy to compile more information 
regarding the number, nature, and timing of testing and training events 
that take place within, or in close proximity to, important habitat 
areas, and to refine its scale of analysis of operations to match the 
scale of the habitat areas that are considered to be important. While 
the 2018 HSTT proposed rule, in assessing environmental impacts on 
marine mammals, breaks down estimated impacts by general region (i.e., 
HRC and SOCAL), the resolution is seldom greater than range complex or 
homeport and is not specifically focused on areas of higher biological 
importance. Current and ongoing efforts to identify important habitat 
areas for marine mammals should be used by NMFS and by the Navy as a 
guide to the most appropriate scale(s) for the analysis of operations.
    Response: In their take request and effects analysis provided to 
NMFS, the Navy considered historic use (number and nature of training 
and testing activities) and locational information of training and 
testing activities when developing modelling boxes. The timing of 
training cycles and testing needs varies based on deployment 
requirements to meet current and emerging threats. Due to the 
variability, the Navy's description of its specified activities is 
structured to provide flexibility in training and testing locations, 
timing, and number. In addition, information regarding the exact 
location of sonar usage is classified. Due to the variety of factors, 
many of which influence locations that cannot be predicted in advance 
(e.g., weather), the analysis is completed at a scale that is necessary 
to allow for flexibility. The purpose of the Navy's quantitative 
acoustic analysis is to provide the best estimate of impact/take to 
marine mammals and ESA listed species for the MMPA regulatory and ESA 
section 7 consultation analyses. Specifically, the analysis must take 
into account multiple Navy training and testing activities over large 
areas of the ocean for multiple years; therefore, analyzing activities 
in multiple locations over multiple seasons produces the best estimate 
of impacts/take to inform the 2018 HSTT FEIS/OEIS and NMFS. Also, the 
scale at which spatially explicit marine mammal density models are 
structured is determined by the data collection method and the 
environmental variables that are used to build the model. Therefore, 
altogether, given the variables that determine when and where the Navy 
trains and tests, as well as the resolution of the density data, the 
analysis of potential impacts is scaled to the level that the data 
fidelity will support. NMFS has worked with the Navy over the years to 
increase the spatio-temporal specificity of the descriptions of 
activities planned in or near areas of biological importance (e.g., in 
BIAs or national marine sanctuaries), when possible, and NMFS is 
confident that the granularity of information provided sufficiently 
allows for an accurate assessment of both the impacts of the Navy's 
activities on marine mammal populations and the protective measures 
evaluated to mitigate those impacts.
Monitoring Recommendations
    Comment 87: In a comment on the 2018 HSTT proposed rule, a 
Commenter recommended that NMFS require that the Navy continue to 
conduct long-term monitoring with the aim to provide baseline 
information on occurrence, distribution, and population structure of 
marine mammal species and stocks, and baseline information upon which 
the extent of exposure to disturbance from training and testing 
activities at the individual, and ultimately, population level-impacts, 
and the effectiveness of mitigation measures, can be evaluated. The 
Commenter recommended individual-level behavioral-response studies, 
such as focal follows and tagging using DTAGs, be carried out before, 
during, and after Navy training and testing activities. The Commenter 
recommended prioritizing DTAG studies that further characterize the 
suite of vocalizations related to social interactions. The Commenter 
recommends the use of unmanned aerial vehicles. The Commenter 
recommended that NMFS require the Navy to use these

[[Page 41839]]

technologies for assessing marine mammal behavior before, during, and 
after Navy training and testing (e.g., swim speed and direction, group 
cohesion). 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: 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 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 the Navy and other stakeholders 
that is based on rigorous reporting out from the Navy and the 
researchers doing the work. Further, the Navy is pursuing many of the 
topics that the Commenter identifies, either through the Navy 
monitoring required under the MMPA and ESA, or through Navy-funded 
research programs (ONR and LMR). We are confident that the monitoring 
conducted by the Navy satisfies the requirements of the MMPA.
    With extensive input from NMFS, the Navy established the Strategic 
Planning Process under the marine species monitoring program to help 
structure the evaluation and prioritization of projects for funding. 
Chapter 5 (Mitigation), Section 5.1.2.2.1.3 (Strategic Planning 
Process) of the 2018 HSTT FEIS/OEIS provides a brief overview of the 
Strategic Planning Process. More detail, including the current 
intermediate scientific objectives, is available 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 steering committee evaluate how well a 
potential project would address the primary objectives of the 
monitoring program. NMFS has opportunities to provide input regarding 
the Navy's intermediate scientific objectives as well as providing 
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. 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. (1) Individual-level behavioral-response 
studies--In addition to the Navy's marine species monitoring program, 
investments for individual-level behavioral-response studies, the 
Office of Naval Research Marine Mammals and Biology program and the 
Navy's Living Marine Resources program continue to heavily invest in 
this topic. For example, as of March, 2020 the following representative 
studies are currently being funded:
     Behavioral Responses of Cetaceans to Naval Sonar 2016-2021 
(Organizations: Norwegian Defense Research Establishment, Forsvarets 
forskningsinstitutt, University of St. Andrews Sea Mammal Research 
Unit);
     ACCURATE: ACoustic CUe RATEs for Passive Acoustics Density 
Estimation 2019-2023 (Organization: University of St. Andrews);
     Acoustic Metadata Management for Navy Fleet Operations 
2015-2020 (Organization: San Diego State University);
     Acoustic startle responses as aversive reactions and 
hearing indicators in cetaceans 2016-2020 (Organization: University of 
St. Andrews);
     Analytical Methods to Support the Development of Noise 
Exposure Criteria for Behavioral Response 2018-2022 (Organizations: 
University of St. Andrews Centre for Research into Ecological and 
Environmental Modelling and Harris);
     Assessing resilience of beaked whale populations to human 
impacts: Population structure and genetic diversity in impacted and 
semi-pristine areas 2016-2020 (Organization: University of La Laguna);
     Behavioral and physiological response studies (BPRS) with 
social delphinid cetaceans using operational and simulated military 
mid-frequency active sonar 2019-2022 (Organization: Southall 
Environmental Associates Inc.);
     Behavioral Assessment of Auditory Sensitivity in Hawaiian 
Monk Seals 2018-2020 (Organization: University of California Santa 
Cruz);
     Behavioral response evaluations employing robust baselines 
and actual Navy training (BREVE) 2016-2020 (Organizations: Naval 
Information Warfare Center Pacific, National Marine Mammal Foundation 
Inc.);
     Blue and Fin Whale Density Estimation in the Southern 
California Offshore Range Using PAM Data 2015-2020 (Organization: Texas 
A&M University Galveston);
     Cetaceans, pinnipeds, and humans: Monitoring marine 
mammals in the Arctic and characterizing their acoustic spaces 2018-
2021 (Organization: University of Washington);
     Collection of auditory evoked potential hearing thresholds 
in minke whales 2019-2023 (Organization: National Marine Mammal 
Foundation Inc.) [in partnership with Subcommittee on Ocean Science and 
Technology (SOST)];
     Cuvier's Beaked Whale and Fin Whale Behavior During 
Military Sonar Operations: Using Medium-term Tag Technology to Develop 
Empirical Risk Functions 2017-2021 (Organization: Marine Ecology and 
Telemetry Research);
     Demographics and diving behavior of Cuvier's beaked whales 
at Guadalupe Island, Mexico: A comparative study to better understand 
sonar impacts at SCORE 2018-2021 (Organization: Marine Ecology and 
Telemetry Research);
     Demonstration and Validation of Passive Acoustic Density 
Estimation for Right Whales 2019-2022 (Organization: Syracuse 
University, University of St. Andrews Centre for Research into 
Ecological and Environmental Modelling);
     DenMod: Working Group for the Advancement of Marine 
Species Density Surface Modeling 2017-2021 (Organization: University of 
St. Andrews Centre for Research into Ecological and Environmental 
Modelling);
     Dynamic marine mammal distribution estimation using 
coupled acoustic propagation, habitat suitability and soundscape models 
2018-2020 (Organization: Woods Hole Oceanographic Institution);
     Environmentally influenced Behavioral Response Evaluations 
(E-BREVE) 2019-2022 (Organization: Naval Information Warfare Center 
Pacific);
     Frequency-dependent Growth and Recovery of TTS in 
Bottlenose Dolphins 2017-2020 (Organization: Naval Information Warfare 
Center Pacific);
     Integrating information on displacement caused by mid-
frequency

[[Page 41840]]

active sonar and measurements of prey field into a population 
consequences of disturbance model for beaked whales 2018-2021 
(Organizations: Naval Undersea Warfare Center Newport, University of 
St. Andrews, Monterey Bay Aquarium Research Institute);
     Investigating bone conduction as a pathway for mysticete 
hearing 2019-2023 (Organization: San Diego State University);
     Measuring the Effect of Range on the Behavioral Response 
of Marine Mammals Through the Use of Navy Sonar 2017-2021 
(Organization: Naval Undersea Warfare Center Newport);
     Multi-spaced Measurement of Underwater Sound Fields from 
Explosive Sources 2019-2020 (Organization: University of Washington);
     Off-range beaked whale study: Behavior and demography of 
Cuvier's beaked whale at the Azores 2017-2020 (Organization: Kelp);
     Passive and active acoustic tracking mooring 2019-2020 
(Organization: Scripps Institution of Oceanography);
     Single sensor and compact array localization methods 2016-
2020 (Organization: University of Hawaii);
     Standardizing Methods and Nomenclature for Automated 
Detection of Navy Sonar 2018-2021 Project #LMR-34 (Organization: Naval 
Information Warfare Center Pacific, Naval Undersea Warfare Center 
Newport);
     The diet composition of pilot whales, dwarf sperm whales 
and pygmy sperm whales in the North Pacific 2017-2020 (Organization: 
University of Hawaii);
     The use of Navy range bottom-mounted, bi-directional 
transducers for long-term, deep-ocean prey mapping 2017-2020 
(Organization: Monterey Bay Aquarium Research Institute);
     Towards a mysticete audiogram using humpback whales' 
behavioral response thresholds 2019-2023 (Organization: University of 
Queensland Cetacean Ecology and Acoustics Laboratory) [in partnership 
with SOST];
     Unifying modeling approaches for better understanding and 
characterizing the effects of sound on marine mammals 2019-2022 
(Organization: University of California Santa Cruz);
     Use of `Chirp' Stimuli for Non-invasive, Low-frequency 
Measurement of Marine Mammal Auditory Evoked Potentials 2019-2021 
Project #LMR-39 (Organization: Naval Information Warfare Center 
Pacific); and
     Using context to improve marine mammal classification 
2017-2020 (Organization: San Diego State University).
    (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 March 
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); and
     The wide-band detection and classification system 2018-
2020 (Organization: Woods Hole Oceanographic Institution).
    (3) Unmanned Aerial Vehicles to assess marine mammal behavior 
before, during, and after Navy training and testing activities (e.g., 
swim speed and direction, group cohesion)--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 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 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, relevant data that is 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. General population level trend 
analysis is conducted by NMFS through its stock assessment reports and 
regulatory determinations. The Navy's analysis of effects to 
populations (species and stocks) of all potentially exposed marine 
species, including marine mammals and sea turtles, is based on the best 
available science as discussed in Sections 3.7 (Marine Mammals) and 3.8 
(Reptiles) of the 2018 HSTT FEIS/OEIS. PCoD models, similar to many 
fisheries stock assessment models, once developed will be powerful 
analytical tools when mature. However, currently they are dependent on 
too many unknown factors for these types of models to produce a 
reliable answer. Current ONR and LMR projects supporting improved 
modeling include (as of March, 2020):
     A model for linking physiological measures of individual 
health to population vital rates for cetaceans

[[Page 41841]]

2017-2020 (Organization: National Marine Mammal Foundation Inc.);
     Body condition as a predictor of behavioral responses of 
cetaceans to sonar 2019-2021 (Organization: University of St. Andrews);
     Integrating the results of behavioral response studies 
into models of the population consequences of disturbance 2019-2021 
(Organizations: University of Washington, Naval Undersea Warfare Center 
Newport);
     Developing metrics of animal condition and their linkage 
to vital rates: Further development of the PCoD model 2018-2021 
(Organization: University of California Santa Cruz);
     Development of an index to measure body condition of free-
ranging cetaceans 2016-2020 (Organization: University of California 
Santa Cruz);
     Double Mocha: Phase II Multi-Study Ocean acoustic Human 
effects Analysis 2018-2021 (Organization: University of St. Andrews 
Centre for Research into Ecological and Environmental Modelling);
     Dynamics of eDNA 2018-2020 (Organization: Oregon State 
University);
     Further investigation of blow or exhaled breath condensate 
as a non-invasive tool to monitor the physiological response to 
stressors in cetaceans 2018-2020 (Organization: Mystic Aquarium);
     Heart rate logging in deep diving toothed whales: A new 
tool for assessing responses to disturbance 2016-2020 (Organization: 
San Jose State University);
     Measuring heart rate to assess the stress response in 
large whales 2019-2021 (Organization: Stanford University);
     Measuring stress hormone levels and reproductive rates in 
two species of common dolphins relative to mid-frequency active sonar 
within the greater region of the SOAR range, San Clemente Island, 
California 2017-2020 (Organization: Southwest Fisheries Science 
Center);
     MSM4PCoD: Marine Species Monitoring for the Population 
Consequences of Disturbance 2019-2023 (Organization: University of St. 
Andrews, Sea Mammal Research Unit);
     Neurobiological and physiological measurements from free 
swimming marine mammals 2019-2022 (Organization: Fundacion 
Oceanografic);
     Physiological consequences of flight responses in diving 
mammals: Critical metrics for assessing the impacts of novel 
environmental stimuli on cetaceans and other marine living species 
2017-2020 (Organization: University of California Santa Cruz); and
     Reconstructing stress and stressor profiles in baleen 
whale earplugs 2017-2020 (Organization: Baylor University).
    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/atlantic/current-projects/. 
A list of the monitoring studies that the Navy will be conducting under 
this rule are listed at the bottom of the Monitoring section of the 
2018 HSTT final rule.
    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 HSTT Study Area. Given the scale of the HSTT 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, but is not recommending any changes 
at this time.

Negligible Impact Determination

General
    Comment 88: In a comment on the 2018 HSTT proposed rule, Commenters 
stated that NMFS' analytical approach for negligible impact 
determination is not transparent and that the methods and resulting 
data cannot be substantiated with the information provided. Commenters 
stated that in general, NMFS has based negligible impact determinations 
associated with incidental take authorizations on abundance estimates 
provided either in its Stock Assessment Reports (SARs) or other more 
recent published literature. For the HSTT proposed rule, NMFS used 
abundance estimates as determined by the Navy's underlying density 
estimates rather than abundance estimates from either the SARs or 
published literature. NMFS also did not specify how it determined the 
actual abundance given that many of the densities differ on orders of 
kilometers. Interpolation or smoothing, and potentially extrapolation, 
of data likely would be necessary to achieve NMFS' intended goal--it is 
unclear whether any such methods were implemented. In addition, it is 
unclear whether NMFS estimated the abundances in the same manner beyond 
the U.S. EEZ as it did within the U.S. EEZ for HRC and why it did not 
compare takes within the U.S. EEZ and beyond the U.S. EEZ for SOCAL, 
given that a larger proportion of the Navy's SOCAL action area is 
beyond the U.S.EEZ than HRC. Furthermore, NMFS did not specify how it 
determined the proportion of total takes that would occur beyond the 
U.S. EEZ. Moreover, the ``instances'' of the specific types of taking 
(i.e., mortality, Level A and B harassment) do not match the total 
takes ``inside and outside the EEZ'' in Tables 69-81 (where applicable) 
or those take estimates in Tables 41-42 and 67-68 of the 2018 HSTT 
proposed rule. It also appears the ``instances'' of take columns were 
based on only those takes in the U.S. EEZ for HRC rather than the area 
within and beyond the U.S. EEZ. It further is unclear why takes were 
not apportioned within and beyond the U.S. EEZ for SOCAL. Given that 
the negligible impact determination is based on the total taking in the 
entire study area, NMFS should have partitioned the takes in the 
``instances'' of take columns in Tables 69-81 of the 2018 HSTT proposed 
rule for all activities that occur within and beyond the U.S. EEZ. One 
Commenter further asserts that any ``small numbers'' determination that 
relies on abundance estimates derived simplistically from modeled 
densities is both arbitrary and capricious. The Commenters assert that 
NMFS should, at least for data rich species, derive its absolute 
abundance estimates from NMFS' SARs or more recently published 
literature.
    Response: NMFS' Analysis and Negligible Impact Determination 
section was updated and expanded in the 2018 HSTT final rule to clarify 
the issues the

[[Page 41842]]

Commenters raised here (as well as others). Specifically, though, NMFS 
uses both the Navy-calculated abundance (based on the Navy-calculated 
densities described in detail in the Estimated Take of Marine Mammal 
section) and the SARs abundances, where appropriate, in the negligible 
impact analysis--noting that the nature of the overlap of the Navy 
Study Area with the U.S. EEZ is different in Hawaii versus SOCAL, 
supporting different analytical comparisons.
    NMFS acknowledges that there were a few small errors in the take 
numbers in the proposed rule; however, they have been corrected (i.e., 
the take totals in Tables 41 and 42 of the 2018 HSTT proposed rule for 
a given stock now equal the ``in and outside the U.S. EEZ'' take totals 
in Tables 41 and 42 (of the HSTT final rule) and the minor changes do 
not affect the analysis or determinations in the rule.
    Also, the Commenters are incorrect that the instances of take for 
HRC do not reflect the take both within and outside the U.S. EEZ. They 
do. Lastly, the Commenter mentions the agency making a ``small 
numbers'' determination, but such a determination is not applicable in 
the context of military readiness activities.
    Comment 89: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that the activities proposed by the Navy include high-
intensity noise pollution, vessel traffic, explosions, pile driving, 
and more at a massive scale. According to the Commenter, NMFS has 
underestimated the amount of take and the adverse impact that it will 
have on marine mammals and their habitat.
    Response: NMFS has provided extensive information demonstrating 
that the best available science has been used to estimate the amount of 
take, and further to analyze the impacts that all of these takes 
combined will have on the affected species and stocks. As described in 
the Analysis and Negligible Impact Determination section, this 
information and our associated analyses support the negligible impact 
determinations necessary to issue these regulations.
    Comment 90: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that blue whales exposed to mid-frequency sonar (with 
received levels of 110 to 120 dB re: 1 [mu]Pa) are less likely to 
produce calls associated with feeding behavior. They cite the Goldbogen 
et al. (2013) study (and a subsequent study) as extremely concerning 
because of the potential impacts of sonar on the essential life 
functions of blue whales as it found that sonar can disrupt feeding and 
displace blue whales from high-quality prey patches, significantly 
impacting their foraging ecology, individual fitness, and population 
health. They also state that mid-frequency sonar has been associated 
with several cases of blue whale stranding events and that low-
frequency anthropogenic noise can mask calling behavior, reduce 
communication range, and damage hearing. These impacts from sonar on 
blue whales suggest that the activities' impacts would have long-term, 
non-negligible impacts on the blue whale population.
    Response: As described in this final rule in the Analysis and 
Negligible Impact Determination section, NMFS has fully considered the 
effects that exposure to sonar can have on blue whales, including 
impacts on calls and feeding and those outlined in the Goldbogen study. 
However, as discussed, any individual blue whale is not expected to be 
exposed to sonar and taken on more than several days per year. Thus, 
while vocalizations may be impacted or feeding behaviors temporarily 
disrupted, this small scale of impacts is not expected to affect 
reproductive success or survival of any individuals, especially given 
the limitations on sonar and explosive use within blue whale BIAs. Of 
additional note, while the blue whale behavioral response study (BRS) 
in Southern California documented some foraging responses by blue 
whales to simulated Navy sonar, any response was highly variable by 
individual and context of the exposure. There were, for instance, some 
individual blue whales that did not respond. Recent Navy-funded blue 
whale tracking has documented wide ranging movements through Navy areas 
such that any one area is not used extensively for foraging. More long-
term blue whale residency occurs north of and outside of the HSTT Study 
Area. Further, we disagree with the assertion that MFAS has been 
causally associated with blue whale strandings. This topic was 
discussed at length in the proposed rule and there is no data causally 
linking MFAS use with blue whale strandings.
    Comment 91: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that NMFS cannot consider the additional mortality/
serious injury, including the 0.2 in the proposed authorization for 
ship strike for blue whales in the 2018 HSTT proposed rule, to have a 
negligible impact for this stock. They also state that counts of 
mortality/serious injury do not account for the additional takes 
proposed to be authorized that cumulatively can have population level 
impacts from auditory injury and behavioral disturbance. Similarly, the 
Commenter stated that NMFS cannot consider the proposed authorization 
for 0.4 annual mortality/serious injury to have a negligible impact on 
the CA/OR/WA stock of humpback whales in the 2018 HSTT proposed rule 
because take is already exceeding the potential biological removal, and 
especially concerning is any take authorized for the critically 
endangered Central America population that would have significant 
adverse population impacts.
    Response: As described in detail in the Estimated Take of Marine 
Mammals section, the Navy and NMFS revisited and re-analyzed the Navy's 
initial request of takes by mortality of blue and humpback whales from 
vessel strike and determined that only one strike of either would be 
possible over the course of five years in the 2018 HSTT final rule, and 
therefore authorized the lesser amount. Further, NMFS has expanded and 
refined the discussion of mortality take, PBR, and our negligible 
impact finding in the Serious Injury and Mortality subsection of the 
Analysis and Negligible Impact Determination section and does not 
repeat it here.
    Comment 92: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that the estimated population size for the Hawaii 
stock of sei whales is only 178 animals, and the potential biological 
removal is 0.2 whales per year. According to the Commenter, NMFS admits 
that the mortality for the Hawaii stock of sei whales is above 
potential biological removal. The Commenter asserted that the 
conclusion that the action will have a negligible impact on this stock 
is arbitrary and capricious.
    Response: As described in detail in the Estimated Take of Marine 
Mammals section, the Navy and NMFS revisited and re-analyzed the Navy's 
initial request for the take of a sei whale from vessel strike and 
determined that this take is unlikely to occur and, therefore, it is 
not authorized.
    Comment 93: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that any take of Hawaiian monk seal by the proposed 
activities will have a non-negligible impact given the precarious 
status of this species.
    Response: NMFS' rationale for finding that the Navy's activity will 
have a negligible impact on monk seals is included in the Pinniped 
subsection of the Analysis and Negligible Impact Determination section 
and is not re-printed here. Nonetheless, we reiterate that no mortality 
or injury due to tissue damage is anticipated or authorized, only one 
instance of PTS is estimated

[[Page 41843]]

and authorized, and no individual monk seal is expected to be exposed 
to stressors that would result in take more than a few days a year. 
Further, the Hawaii Island and 4-Island Region mitigation areas provide 
significant protection of monk seal critical habitat in the Main 
Hawaiian Islands, reducing impacts from sonar and explosives around a 
large portion of pupping beaches and foraging habitat, as described in 
the Mitigation Measures section.
    Comment 94: In a comment on the 2019 HSTT proposed rule, Commenters 
stated that satellite telemetry data and eight years' worth of photo-
identification and mark-recapture data, representing the best available 
science, indicate that San Nicolas Basin represents an area of high 
site fidelity, and residency, for a small population of Cuvier's beaked 
whales associated with San Clemente Island (Falcone et al., 2009; 
Falcone et al., 2014; Schorr et al., 2014). They stated that the 
population's primary habitat overlaps directly with the SOAR Range. 
They asserted that many factors--their repeated exposure to Navy 
activities, their clear foraging-related responses to both controlled 
sonar playbacks (DeRuiter et al., 2013) and live exercises (Falcone et 
al., 2017), and their small abundance and apparently limited range--
raise obvious concerns about population-level consequences for these 
whales (Claridge and Dunn, 2014, Moretti et al., 2015). The Commenters 
asserted that without meaningful additional mitigation, they do not see 
how NMFS can conclude that population-level harm would not occur or, 
ultimately, how NMFS can credibly reach a finding of negligible impact 
with respect to this population.
    Response: As noted in our response to a similar comment (Comment 97 
below) on the 2018 HSTT proposed rule, NMFS acknowledges the 
sensitivity of small resident populations both in our analyses and in 
the identification of mitigation measures, where appropriate. However, 
we are required to make our negligible impact determination in the 
context of the MMPA-designated stock, which, in the case of the CA/OR/
WA stock of Cuvier's beaked whale, spans the U.S. EEZ off the U.S. West 
Coast. As described in our responses to previous comments, NMFS and the 
Navy have fully accounted for the sensitivity of Cuvier's beaked whales 
in the behavioral thresholds and the estimation of take. NMFS has also 
considered the potential impacts of repeated takes on individuals that 
show site fidelity. Nonetheless, in 2020, an estimate of overall 
abundance of Cuvier's beaked whales at the Navy's instrumented range in 
San Nicolas Basin was obtained using new dive-counting acoustic methods 
and an archive of passive acoustic M3R data representing 49,855 hrs of 
data (DiMarzio et al., 2020; Moretti, 2017). Over the ten-year period 
from 2010-2019, there was no observed decrease and perhaps a slight 
increase in annual Cuvier's beaked whale abundance within San Nicolas 
Basin (DiMarzio et al., 2020). There does appear to be a repeated dip 
in population numbers and associated echolocation clicks during the 
fall centered around August and September (Moretti, 2017, DiMarzio et 
al., 2020). A similar August and September dip was noted by researchers 
using stand-alone off-range bottom passive acoustic devices in Southern 
California ([Scaron]irovi[cacute] et al., 2016; Rice et al., 2017, 
2019, 2020). This dip in abundance may be tied to some as of yet 
unknown population dynamic or oceanographic and prey availability 
dynamics.
    Comment 95: In a comment on the 2019 HSTT proposed rule, due to the 
circumstances for gray whales (described in Comment 78) Commenters 
asserted that in considering the effects of acoustic exposure on gray 
whales, NMFS cannot presume that the consequences of the Navy's 
behavioral disruption will be ``minor'' or ``short-term.'' They 
asserted that NMFS must carefully consider the biological context of 
behavioral disruption on that species and evaluate the meaningful risk 
of serious or severe consequences, including mortality.
    Response: NMFS acknowledges that individual marine mammals that are 
emaciated or have underlying health issues, such as some gray whales 
have experienced, may be impacted more severely by exposure to 
additional stressors than healthy animals. However, the expected nature 
and short duration of any individual gray whale's exposure to Navy 
activity is still such that impacts would not be expected to be 
compounded to the point where individual fitness is affected. 
Specifically, gray whales seasonally migrate through the Southern 
California portion of the HSTT Study Area and are not known to forage 
in the HSTT Study Area. Most gray whales spend only brief periods of 
time (days) in the HSTT Study Area and we have no reason to expect that 
the anticipated incremental, short term, and predominately low-level 
behavioral responses to transitory stressors such as Navy training and 
testing activities will have impacts on individual gray whale fitness, 
much less adversely affect the stock at the population level. Also, as 
noted previously, both the Eastern Pacific stock (not ESA listed) and 
the Western Pacific stock of gray whales is described as increasing in 
the 2018 final SARs (the most recent SARs for these stocks). The 
population size of the Eastern North Pacific gray whale stock has 
increased over several decades despite an UME in 1999 and 2000.
Cumulative and Aggregate Effects
    Comment 96: In a comment on the 2018 HSTT proposed rule, a 
Commenter asserted that NMFS has not apparently considered the impact 
of Navy activities on a population basis for many of the marine mammal 
populations within the HSTT Study Area. Instead, it has lodged 
discussion for many populations within broader categories, most 
prominently ``mysticetes'' (14 populations) and ``odontocetes'' (37 
populations), 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. 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. 
Additionally, the Commenter stated that NMFS assumed 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.
    Response: NMFS provides information regarding broader groups in 
order to avoid repeating information that is applicable across multiple 
species or stocks, but analyses have been conducted and determinations 
made specific to each stock. The method used to avoid repeating 
information applicable to a number of species or stocks while also 
presenting and integrating all information applicable to particular 
species or stocks is described in the rule. Also, NMFS' analysis does 
address the fact that some individuals may be repeatedly impacted and 
how those impacts may or may not accrue to more serious effects. The 
Analysis and Negligible Impact Determination section has been expanded 
and refined to better explain this.
    Comment 97: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that NMFS' negligible impact analysis for Cuvier's 
beaked whales is

[[Page 41844]]

predicated on a single take estimate for the CA/OR/WA stock. This is 
deeply problematic as the species is known to occur in small, resident 
populations within the SOCAL Range Complex. These populations are 
acutely vulnerable to Navy sonar. Cuvier's beaked whales have 
repeatedly been associated with sonar-related pathology, are known to 
react strongly to sonar at distances up to 100 kilometers, and are 
universally regarded to be among the most sensitive of all marine 
mammals to anthropogenic noise (Falcone et al., 2017). Some 
populations, such as the one in San Nicolas Basin that coincides with 
the Navy's much-used Southern California ASW Range (SOAR), are 
repeatedly exposed to sonar, posing the same risk of population-wide 
harm documented on a Navy range in the Bahamas (Falcone and Schorr, 
2013). The broad take estimates presented in the 2018 HSTT proposed 
rule, and the negligible impact analysis that they are meant to 
support, provide no insight into the specific impacts proposed for 
these small populations.
    Response: NMFS acknowledges the sensitivity of small resident 
populations both in our analyses and in the identification of 
mitigation measures, where appropriate. However, we are required to 
make our negligible impact determination in the context of the MMPA-
designated stock, which, in the case of the CA/OR/WA stock of Cuvier's 
beaked whale, spans the U.S. EEZ off the West Coast. As described in 
our responses to previous comments, NMFS and the Navy have fully 
accounted for the sensitivity of Cuvier's beaked whales in the 
behavioral thresholds and the estimation of take. Further, contrary to 
the assertions of the Commenter, NMFS has absolutely considered the 
potential impacts of repeated takes on individuals that show site 
fidelity and that analysis can be found in the Analysis and Negligible 
Impact Determination section, which has been refined and updated since 
the proposed rule based on public input. Nonetheless, in 2020, an 
estimate of overall abundance of Cuvier's beaked whales at the Navy's 
instrumented range in San Nicolas Basin was obtained using new dive-
counting acoustic methods and an archive of passive acoustic M3R data 
representing 49,855 hrs of data (DiMarzio et al., 2020; Moretti, 2017). 
Over the ten-year period from 2010-2019, there was no observed decrease 
and perhaps a slight increase in annual Cuvier's beaked whale abundance 
within San Nicolas Basin (DiMarzio et al., 2020). There does appear to 
be a repeated dip in population numbers and associated echolocation 
clicks during the fall centered around August and September (Moretti, 
2017, DiMarzio et al., 2020). A similar August and September dip was 
noted by researchers using stand-alone off-range bottom passive 
acoustic devices in Southern California ([Scaron]irovi[cacute] et al., 
2016; Rice et al., 2017, 2019, 2020). This dip in abundance may be tied 
to some as of yet unknown population dynamic or oceanographic and prey 
availability dynamics.
    Comment 98: In a comment on the 2018 HSTT proposed rule, a 
Commenter asserted that with respect to mortalities and serious 
injuries, NMFS' application of potential biological removal (PBR) is 
unclear and may not be consistent with its prior interpretations. The 
agency recognizes that PBR is a factor in determining whether the 
negligible impact threshold has been exceeded, but argues that, since 
PBR and negligible impact are different statutory standards, NMFS might 
find that an activity that kills marine mammals beyond what PBR could 
support would not necessarily exceed the negligible impact threshold. 
Regardless, however, of whether Congress intended PBR as a formal 
constraint on NMFS' ability to issue incidental take permits under 
section 101(a)(5), NMFS' own definition of ``negligible impact'' 
prevents it from authorizing mortalities or other takes that would 
threaten the sustainability of marine mammal stocks. Mortalities and 
serious injuries exceeding potential biological removal levels would do 
just that.
    Additionally, in assessing the consequences of authorized mortality 
below PBR, NMFS applies an ``insignificance'' standard, such that any 
lethal take below 10 percent of residual PBR is presumed not to exceed 
the negligible impact threshold. This approach seems inconsistent, 
however, with the regulatory thresholds established for action under 
the commercial fisheries provision of the Act, where bycatch of 1 
percent of total PBR triggers mandatory take reduction procedures for 
strategic marine mammal stocks. See 16 U.S.C. 1387(f)(1); 83 FR 5349, 
5349 (Feb. 7, 2018). NMFS should clarify why it has chosen 10 percent 
rather than, for example, 1 percent as its ``insignificance'' 
threshold, at least for endangered species and other populations 
designated as strategic under the MMPA.
    Response: NMFS disagrees that the consideration of PBR is unclear 
and notes that the narrative describing the application of PBR has been 
updated in this final rule to further explain how the agency considers 
this metric in the context of the negligible impact determination under 
section 101(a)(5)(A) (see the Serious Injury and Mortality sub-section 
of the Analysis and Negligible Impact Determination section) and is not 
repeated here. That discussion includes how PBR is calculated and 
therefore how it is possible for anticipated M/SI to exceed PBR or 
residual PBR and yet not adversely affect a particular species or stock 
through effects on annual rates of recruitment and survival.
    Regarding the insignificance threshold, as explained in the rule, 
residual PBR is a metric that can be used to inform the assessment of 
M/SI impacts, and the insignificance threshold is an analytical tool to 
help prioritize analyst effort. But the insignificance threshold is not 
applied as a strict presumption as described by the Commenter. Although 
it is true that as a general matter M/SI that is less than 10 percent 
of residual PBR should have no effect on rates of recruitment or 
survival, the agency will consider whether there are other factors that 
should be considered, such as whether an UME is affecting the species 
or stock.
    The 10 percent insignificance threshold is an analytical tool that 
indicates that the potential mortality or serious injury is an 
insignificant incremental increase in anthropogenic mortality and 
serious injury that alone (in the absence of any other take and any 
other unusual circumstances) would clearly not affect rates of 
recruitment or survival. As such, potential mortality and serious 
injury at the insignificance-threshold level or below is evaluated in 
light of other relevant factors (such as an ongoing UME) and then 
considered in conjunction with any anticipated Level A or Level B 
harassment take to determine if the total take would affect annual 
rates of recruitment or survival. Ten percent was selected because it 
corresponds to the insignificance threshold under the MMPA framework 
for authorizing incidental take of marine mammals resulting from 
commercial fisheries. There the insignificance threshold, which also is 
10 percent of PBR, is ``the upper limit of annual incidental mortality 
and serious injury of marine mammal stocks by commercial fisheries that 
can be considered insignificant levels approaching a zero mortality and 
serious injury rate'' (see 50 CFR 229.2). A threshold that represents 
an insignificant level of mortality or serious injury approaching a 
zero mortality and serious injury rate was thought to be an appropriate 
level to indicate when, absent other factors, the

[[Page 41845]]

agency can be confident that expected mortality and serious injury will 
not affect annual rates of recruitment and survival, without the need 
for significant additional analysis.
    Regarding the claim that NMFS' interpretation of PBR may be 
inconsistent with prior interpretations, we disagree. Rather, NMFS' 
interpretation of PBR has been utilized appropriately within the 
context of the different MMPA programs and associated statutory 
standards it has informed. The application of PBR under section 
101(a)(5)(A) also has developed and been refined in response to 
litigation and as the amount of and nature of M/SI requested pursuant 
to this section has changed over time, thereby calling for the agency 
to take a closer look at how M/SI relative to PBR relates to effects on 
rates of recruitment and survival.
    Specifically, until recently, NMFS had used PBR relatively few 
times to support determinations outside of the context of MMPA 
commercial fisheries assessments and decisions. Indeed, in Georgia 
Aquarium, Inc. v. Pritzker, 135 F. Supp.3d 1280 (N.D. Ga. 2015), in 
ruling on a lawsuit in which the plaintiffs sought to use PBR as the 
reason they should be allowed to import animals from the Sahklin-Amur 
stock of beluga whales for public display, the Court summarized a 
``handful'' of cases where NMFS had used PBR to support certain agency 
findings. The Court agreed that the agency does not have a ``practice 
and policy'' of applying PBR in all circumstances. Importantly, the 
Court stated that ``NMFS has shown that where the Agency has considered 
PBR outside of the U.S. commercial fisheries context, it has treated 
PBR as only one `quantitative tool' and that it is not used as the sole 
basis for its impact analyses,'' just as NMFS has done here for its 
negligible impact analyses.
    The examples considered by the Georgia Aquarium Court involved 
scientific research permits or subsistence harvest decisions where 
reference to PBR was one consideration among several. Thus, in one of 
the examples referenced by the Court, PBR was included to evaluate 
different alternatives in a 2007 EIS developed in support of future 
grants and permits related to research on northern fur seals and 
Steller sea lions (available at https://repository.library.noaa.gov/view/noaa/17331). Similarly, in the 2015 draft EIS on the Makah Tribe's 
request to hunt gray whales, different levels of harvest were compared 
against PBR along with other considerations in the various alternatives 
(available at https://www.westcoast.fisheries.noaa.gov/publications/protected_species/marine_mammals/cetaceans/gray_whales/makah_deis_feb_2015.pdf). Consistent with what the Georgia Aquarium 
Court found, in both of those documents PBR was one consideration in 
developing alternatives for the agency's EIS and not determinative in 
any decision-making process.
    After 2013 in response to an incidental take authorization request 
from NMFS' Southwest Fisheries Science Center that contained PBR 
analysis and more particularly in response to a District Court's March 
2015 ruling that NMFS' failure to consider PBR when evaluating lethal 
take under section 101(a)(5)(A) violated the requirement to use the 
best available science (see Conservation Council for Hawaii v. National 
Marine Fisheries Service, 97 F. Supp.3d 1210 (D. Haw. 2015)), NMFS 
began to systematically consider the role of PBR when evaluating the 
effects of M/SI during section 101(a)(5)(A) rulemakings. Previously, in 
1996 shortly after the PBR metric was first introduced, NMFS denied a 
request from the U.S. Coast Guard for an incidental take authorization 
for their vessel and aircraft operations, seemingly solely on the basis 
of the potential for ship strike in relation to PBR. The decision did 
not appear to consider other factors that might also have informed the 
potential for ship strike of a North Atlantic right whale in relation 
to the negligible impact standard.
    During the following years and until the Court's decision in 
Conservation Council and the agency issuing the proposed incidental 
take authorization for the Southwest Fisheries Science Center, NMFS 
issued incidental take regulations without referencing PBR. Thereafter, 
however, NMFS began considering and articulating the appropriate role 
of PBR when processing incidental take requests for M/SI under section 
101(a)(5)(A). Consistent with the interpretation of PBR across the rest 
of the agency, NMFS' Permits and Conservation Division has been using 
PBR as a tool to inform the negligible impact analysis under section 
101(a)(5)(A), recognizing that it is not a dispositive threshold that 
automatically determines whether a given amount of M/SI either does or 
does not exceed a negligible impact on the affected species or stock.
    Comment 99: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that NMFS failed to adequately assess the aggregate 
effects of all of the Navy's activities included in the rule. The 
Commenter alleges that NMFS' lack of analysis of these aggregate 
impacts, which is essential to any negligible impact determination, 
represents a glaring omission from the proposed rule. While NMFS states 
that Level B behavioral harassment (aside from those 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.
    Response: NMFS did analyze the potential for aggregate effects from 
mortality, injury, masking, habitat effects, energetic costs, stress, 
hearing loss, and behavioral harassment from the Navy's activities in 
reaching the negligible impact determinations. Significant additional 
discussion has been added to the Analysis and Negligible Impact 
Determination section of the final rule to better explain the potential 
for aggregate or cumulative effects on individuals as well as how these 
effects on individuals relate to potential effects on annual rates of 
recruitment and survival for each species or stock.
    In addition, NMFS fully considers the potential for aggregate 
effects from all Navy activities. We also consider UMEs 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 and stock-specific 
assessments in the Analysis and Negligible Impact Determination section 
(which have been updated and expanded) pull together and address the 
combined mortality, injury, behavioral harassment, and other effects of 
the aggregate HSTT 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 or stocks 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 
research from NMFS and Navy-funded marine mammal studies, there is no 
evidence that ``population-level harm'' to marine mammals, including 
beaked whales, is occurring in the HSTT Study Area. The presence of 
numerous small, resident populations of cetaceans, documented high 
abundances, and populations trending to increase for many marine 
mammals species in the area suggests there are not likely population-
level

[[Page 41846]]

consequences resulting from decades of ongoing Navy training and 
testing activities. Through the process described in the rule and the 
LOAs, the Navy will work with NMFS 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 harassment 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 harassment, PTS, and TTS).
    Comment 100: In a comment on the 2018 HSTT proposed rule, 
Commenters asserted that in reaching our MMPA negligible impact 
finding, NMFS did not adequately consider the cumulative impacts of the 
Navy's activities when combined with the effects of other non-Navy 
activities.
    Response: Both the statute and the agency's implementing 
regulations call for analysis of the effects of the applicant's 
activities on the affected species and stocks, not analysis of other 
unrelated activities and their impacts on the species and stocks. That 
does not mean, however, that effects on the species and stocks caused 
by other non-Navy activities are ignored. The preamble for NMFS' 
implementing regulations under section 101(a)(5) (54 FR 40338; 
September 29, 1989) explains in response to comments that the impacts 
from other past and ongoing anthropogenic activities are to be 
incorporated into the negligible impact analysis via their impacts on 
the environmental baseline. Consistent with that direction, NMFS has 
factored into its negligible impact analyses the impacts of other past 
and ongoing anthropogenic activities via their impacts on the baseline 
(e.g., as reflected in the density/distribution and status of the 
species, population size and growth rate, and other relevant stressors 
(such as incidental mortality in commercial fisheries or UMEs)). See 
the Analysis and Negligible Impact Determination section of this rule 
and the 2018 HSTT final rule.
    Our 1989 final rule for the MMPA implementing regulations also 
addressed public comments regarding cumulative effects from future, 
unrelated activities. There we stated that such effects are not 
considered in making findings under section 101(a)(5) concerning 
negligible impact. We indicated that NMFS would consider cumulative 
effects that are reasonably foreseeable when preparing a NEPA analysis 
and also that reasonably foreseeable cumulative effects would be 
considered under section 7 of the ESA for ESA-listed species.
    Also, as described further in the Analysis and Negligible Impact 
Determination section of the final rule, NMFS evaluated the impacts of 
HSTT authorized mortality on the affected stocks in consideration of 
other anticipated human-caused mortality, including the mortality 
predicted in the SARs for other activities along with other NMFS-
permitted mortality (i.e., authorized as part of the Southwest 
Fisheries Science Center rule), using multiple factors, including PBR. 
As described in more detail in the Analysis and Negligible Impact 
Determination section, PBR was designed to identify the maximum number 
of animals that may be removed from a stock (not including natural 
mortalities) while allowing that stock to reach or maintain its OSP and 
is also helpful in informing whether mortality will adversely affect 
annual rates of recruitment or survival in the context of a section 
101(a)(5)(A).

NEPA

    Comment 101: In a comment on the 2018 HSTT proposed rule, 
Commenters stated that NMFS cannot rely on the 2018 HSTT FEIS/OEIS to 
fulfill its obligations under NEPA because the purpose and need is too 
narrow and does not support NMFS' MMPA action, and therefore the 2018 
HSTT FEIS/OEIS does not explore a reasonable range of alternatives.
    Response: The proposed action at issue is the Navy's proposal to 
conduct testing and training activities in the HSTT Study Area. NMFS is 
a cooperating agency for that proposed action, as it has jurisdiction 
by law and special expertise over marine resources impacted by the 
proposed action, including marine mammals and federally-listed 
threatened and endangered species. Consistent with the regulations 
published by the Council on Environmental Quality (CEQ), it is common 
and sound NEPA practice for NOAA to 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 
must be satisfied that the EIS adequately addresses the impacts of 
issuing the MMPA incidental take authorization and that NOAA's comments 
and concerns have been adequately addressed. There is no requirement in 
CEQ regulations that NMFS, as a cooperating agency, issue a separate 
purpose and need statement in order to ensure adequacy and sufficiency 
for adoption. Nevertheless, the Navy, in coordination with NMFS, has 
clarified the statement of purpose and need in the 2018 HSTT FEIS/OEIS 
to more explicitly acknowledge NMFS' action of issuing an MMPA 
incidental take authorization. NMFS also clarified how its regulatory 
role under the MMPA related to the Navy's activities. NMFS' early 
participation in the NEPA process and role in shaping and informing 
analyses using its special expertise ensured that the analysis in the 
2018 HSTT FEIS/OEIS is sufficient for purposes of NMFS' own NEPA 
obligations related to its issuance of incidental take authorization 
under the MMPA.
    Regarding the alternatives, NMFS' early involvement in development 
of the 2018 HSTT FEIS/OEIS and role in evaluating the effects of 
incidental take under the MMPA ensured that the 2018 HSTT FEIS/OEIS 
would include adequate analysis of a reasonable range of alternatives. 
The 2018 HSTT FEIS/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 options in potentially issuing an MMPA authorization, 
which, if the authorization may be issued, 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 EIS, including the purpose and 
need statement and range of alternatives, and determined that the 2018 
HSTT FEIS/OEIS fully satisfies NMFS' NEPA obligations related to its 
decision to issue the MMPA final rule and associated LOAs, and we have 
adopted it.

Endangered Species Act

    Comment 102: In a comment on the 2018 HSTT proposed rule, a 
Commenter stated that under the ESA NMFS has the discretion to impose 
terms, conditions, and mitigation on any authorization.

[[Page 41847]]

They believe the proposed action clearly affects listed whales, sea 
turtles, and Hawaiian monk seals, triggering the duty to consult. The 
Commenter urged NMFS to fully comply with the ESA and implement robust 
reasonable and prudent alternatives and conservation measures to avoid 
harm to endangered species and their habitats.
    Response: NMFS has fully complied with the ESA. The agency 
consulted pursuant to section 7 of the ESA and NMFS' ESA Interagency 
Cooperation Division provided a biological opinion concluding that 
NMFS' action of issuing MMPA incidental take regulations for the Navy 
HSTT activities would not jeopardize the continued existence of any 
threatened or endangered species and nor would it adversely modify any 
designated critical habitat. The biological opinion may be viewed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.

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

    Marine mammal species and their associated stocks that have the 
potential to occur in the HSTT Study Area are presented in Table 10 
along with the best/minimum abundance estimate and associated 
coefficient of variation value. The Navy anticipates the take of 
individuals from 38 marine mammal species \3\ by Level A harassment and 
Level B harassment incidental to training and testing activities from 
the use of sonar and other transducers, in-water detonations, air guns, 
and impact pile driving/vibratory extraction activities. The Navy 
requested authorization for 13 serious injuries or mortalities combined 
of two marine mammal stocks from explosives, and three takes of large 
whales by serious injury or mortality from vessel strikes over the 
seven-year period. Two marine mammal species, the Hawaiian monk seal 
and the Main Hawaiian Islands Insular Distinct Population Segment (DPS) 
of false killer whale, have critical habitat designated under the 
Endangered Species Act (16 U.S.C. 1531 et seq.; ESA) in the HSTT Study 
Area.
---------------------------------------------------------------------------

    \3\ In the 2018 HSTT final rule the number of species was 
unintentionally presented incorrectly as 39 and is corrected here. 
This transcription error does not affect the analysis or conclusions 
reached in the 2018 HSTT final rule.
---------------------------------------------------------------------------

    We presented a detailed discussion of marine mammals and their 
occurrence in the HSTT Study Area, inclusive of important marine mammal 
habitat (e.g., ESA-designated critical habitat, biologically important 
areas (BIAs), national marine sanctuaries (NMSs)), and unusual 
mortality events (UMEs) in the 2018 HSTT proposed rule and 2018 HSTT 
final rule; please see these rules and the 2017 and 2019 Navy 
applications for complete information. There have been no changes to 
important marine mammal habitat, BIAs, NMSs, or ESA designated critical 
habitat since the issuance of the 2018 HSTT final rule; therefore the 
information that supports our determinations here can be found in the 
2018 HSTT proposed and final rules. However, since publication of the 
2018 HSTT final rule, NMFS published a proposed rule to designate ESA 
critical habitat for the Central America and Mexico DPSs of humpback 
whales on October 9, 2019 (84 FR 54354). In the proposed rule only 
critical habitat Unit 19 overlapped with the HSTT Study Area, and NMFS 
proposed to exclude this unit from the critical habitat designation 
based on consideration of national security. A final rule designating 
critical habitat for these two DPSs of humpback whales has not been 
published.
    NMFS also has reviewed the most recent 2019 draft Stock Assessment 
Reports (SARs) and 2018 final SARs (Carretta et al., 2019, which can be 
found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments); information on relevant 
UMEs; and new scientific literature (see the Potential Effects of 
Specified Activities on Marine Mammals and their Habitat section), and 
determined that none of these nor any other new information changes our 
determination of which species or stocks have the potential to be 
affected by the Navy's activities or the pertinent information in the 
Description of Marine Mammals and Their Habitat in the Area of the 
Specified Activities section in the 2018 HSTT proposed and final rules. 
Therefore, the information presented in those sections of the 2018 HSTT 
proposed and final rules remains current and valid.
    The species considered but not carried forward for analysis are two 
American Samoa stocks of spinner dolphins--(1) the Kure and Midway 
stock and (2) the Pearl and Hermes stock. There is no potential for 
overlap with any stressors from Navy activities and therefore there 
would be no incidental takes, in which case, these stocks are not 
considered further.

                                              Table 10--Marine Mammal Occurrence Within the HSTT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Status \1\                                                Stock abundance
         Common name            Scientific name        Stock      ------------------------------------    Occurrence        Seasonal       (CV)/minimum
                                                                         MMPA               ESA                             absence       population \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale...................  Balaenoptera      Eastern North     Strategic,        Endangered......  Southern         ...............  1,496 (0.44)/
                                musculus.         Pacific.          Depleted.                           California.                       1,050
                                                 Central North     Strategic,        Endangered......  Hawaii.........  Summer.........  133 (1.09)/63
                                                  Pacific.          Depleted.
Bryde's whale................  Balaenoptera      Eastern Tropical  ................  ................  Southern         ...............  unknown
                                brydei/edeni.     Pacific.                                              California.
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  1,751 (0.29)/
                                                                                                                                          1,378
Fin whale....................  Balaenoptera      CA/OR/WA........  Strategic,        Endangered......  Southern         ...............  9,029 (0.12)/
                                physalus.                           Depleted.                           California.                       8,127
                                                 Hawaii..........  Strategic,        Endangered......  Hawaii.........  Summer.........  154 (1.05)/75
                                                                    Depleted.
Gray whale...................  Eschrichtius      Eastern North     ................  ................  Southern         ...............  26,960 (0.05)/
                                robustus.         Pacific.                                              California.                       25,849
                                                 Western North     Strategic,        Endangered......  Southern         ...............  290 (NA)/271
                                                  Pacific.          Depleted.                           California.
Humpback whale...............  Megaptera         CA/OR/WA........  Strategic,        Threatened/       Southern         ...............  2,900 (0.05)/
                                novaeangliae.                       Depleted.         Endangered \3\.   California.                       2,784
                                                 Central North     Strategic.......  ................  Hawaii.........  Summer.........  10,103 (0.30)/
                                                  Pacific.                                                                                7,891
Minke whale..................  Balaenoptera      CA/OR/WA........  ................  ................  Southern         ...............  636 (0.72)/369
                                acutorostrata.                                                          California.
                                                 Hawaii..........  ................  ................  Hawaii.........  Summer.........  unknown
Sei whale....................  Balaenoptera      Eastern North     Strategic,        Endangered......  Southern         ...............  519 (0.40)/374
                                borealis.         Pacific.          Depleted.                           California.
                                                 Hawaii..........  Strategic,        Endangered......  Hawaii.........  Summer.........  391 (0.90)/204
                                                                    Depleted.
Sperm whale..................  Physeter          CA/OR/WA........  Strategic,        Endangered......  Southern         ...............  1,997 (0.57)/
                                macrocephalus.                      Depleted.                           California.                       1,270
                                                 Hawaii..........  Strategic,        Endangered......  Hawaii.........  ...............  4,559 (0.33)/
                                                                    Depleted.                                                             3,478
Pygmy sperm whale............  Kogia breviceps.  CA/OR/WA........  ................  ................  Southern         Winter and Fall  4,111 (1.12)/
                                                                                                        California.                       1,924
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  unknown

[[Page 41848]]

 
Dwarf sperm whale............  Kogia sima......  CA/OR/WA........  ................  ................  Southern         ...............  unknown
                                                                                                        California.
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  unknown
Baird's beaked whale.........  Berardius         CA/OR/WA........  ................  ................  Southern         ...............  2,697 (0.60)/
                                bairdii.                                                                California.                       1,633
Blainville's beaked whale....  Mesoplodon        Hawaii..........  ................  ................  Hawaii.........  ...............  2,105 (1.13)/
                                densirostris.                                                                                             980
Cuvier's beaked whale........  Ziphius           CA/OR/WA........  ................  ................  Southern         ...............  3,274 (0.67)/
                                cavirostris.                                                            California.                       2,059
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  723 0.69/428
Longman's beaked whale.......  Indopacetus       Hawaii..........  ................  ................  Hawaii.........  ...............  7,619 (0.66)/
                                pacificus.                                                                                                4,592
Mesoplodon beaked whales.....  Mesoplodon spp..  CA/OR/WA........  ................  ................  Southern         ...............  3,044 (0.54)/
                                                                                                        California.                       1,967
Common Bottlenose dolphin....  Tursiops          California        ................  ................  Southern         ...............  453 (0.06)/346
                                truncatus.        Coastal.                                              California.
                                                 CA/OR/WA          ................  ................  Southern         ...............  1,924 (0.54)/
                                                  Offshore.                                             California.                       1,255
                                                 Hawaii Pelagic..  ................  ................  Hawaii.........  ...............  21,815 (0.57)/
                                                                                                                                          13,957
                                                 Kauai and Niihau  ................  ................  Hawaii.........  ...............  NA NA/97
                                                 Oahu............  ................  ................  Hawaii.........  ...............  NA
                                                 4-Islands.......  ................  ................  Hawaii.........  ...............  NA
                                                 Hawaii Island...  ................  ................  Hawaii.........  ...............  NA NA/91
False killer whale...........  Pseudorca         Main Hawaiian     Strategic,        Endangered......  Hawaii.........  ...............  167 (0.14)/149
                                crassidens.       Islands Insular.  Depleted.
                                                 Hawaii Pelagic..  ................  ................  Hawaii.........  ...............  1,540 (0.66)/
                                                                                                                                          928
                                                 Northwestern      ................  ................  Hawaii.........  ...............  617 (1.11)/290
                                                  Hawaiian
                                                  Islands.
Fraser's dolphin.............  Lagenodelphis     Hawaii..........  ................  ................  Hawaii.........  ...............  51,491 (0.66)/
                                hosei.                                                                                                    31,034
Killer whale.................  Orcinus orca....  Eastern North     ................  ................  Southern         ...............  300 (0.1)/276
                                                  Pacific                                               California.
                                                  Offshore.
                                                 West Coast        ................  ................  Southern         ...............  243 unknown/243
                                                  Transient.                                            California.
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  146 (0.96)/74
Long-beaked common dolphin...  Delphinus         California......  ................  ................  Southern         ...............  101,305 (0.49)/
                                capensis.                                                               California.                       68,432
Melon-headed whale...........  Peponocephala     Hawaiian Islands  ................  ................  Hawaii.........  ...............  8,666 (1.00)/
                                electra.                                                                                                  4,299
                                                 Kohala Resident.  ................  ................  Hawaii.........  ...............  447 (0.12)/404
Northern right whale dolphin.  Lissodelphis      CA/OR/WA........  ................  ................  Southern         ...............  26,556 (0.44)/
                                borealis.                                                               California.                       18,608
Pacific white-sided dolphin..  Lagenorhynchus    CA/OR/WA........  ................  ................  Southern         ...............  26,814 (0.28)/
                                obliquidens.                                                            California.                       21,195
Pantropical spotted dolphin..  Stenella          Oahu............  ................  ................  Hawaii.........  ...............  unknown
                                attenuata.
                                                 4-Islands.......  ................  ................  Hawaii.........  ...............  unknown
                                                 Hawaii Island...  ................  ................  Hawaii.........  ...............  unknown
                                                 Hawaii Pelagic..  ................  ................  Hawaii.........  ...............  55,795 (0.40)/
                                                                                                                                          40,338
Pygmy killer whale...........  Feresa attenuata  Tropical........  ................  ................  Southern         Winter & Spring  unknown
                                                                                                        California.
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  10,640 (0.53)/
                                                                                                                                          6,998
Risso's dolphins.............  Grampus griseus.  CA/OR/WA........  ................  ................  Southern         ...............  6,336 (0.32)/
                                                                                                        California.                       4,817
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  11,613 (0.43)/
                                                                                                                                          8,210
Rough-toothed dolphin........  Steno             NSD\4\..........  ................  ................  Southern         ...............  unknown
                                bredanensis.                                                            California.
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  72,528 (0.39)/
                                                                                                                                          52,833
Short-beaked common dolphin..  Delphinus         CA/OR/WA........  ................  ................  Southern         ...............  969,861 (0.17)/
                                delphis.                                                                California.                       839,325
Short-finned pilot whale.....  Globicephala      CA/OR/WA........  ................  ................  Southern         ...............  836 (0.79)/466
                                macrorhynchus.                                                          California.
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  19,503 (0.49)/
                                                                                                                                          13,197
Spinner dolphin..............  Stenella          Hawaii Pelagic..  ................  ................  Hawaii.........  ...............  unknown
                                longirostris.
                                                 Hawaii Island...  ................  ................  Hawaii.........  ...............  665 (0.09)/617
                                                 Oahu and 4-       ................  ................  Hawaii.........  ...............  NA
                                                  Islands.
                                                 Kauai and Niihau  ................  ................  Hawaii.........  ...............  NA
                                                 Kure and Midway.  ................  ................  Hawaii.........  ...............  unknown
                                                 Pearl and Hermes  ................  ................  Hawaii.........  ...............  unknown
Striped dolphin..............  Stenella          CA/OR/WA........  ................  ................  Southern         ...............  29,211 (0.20)/
                                coeruleoalba.                                                           California.                       24,782
                                                 Hawaii..........  ................  ................  Hawaii.........  ...............  61,021 (0.38)/
                                                                                                                                          44,922
Dall's porpoise..............  Phocoenoides      CA/OR/WA........  ................  ................  Southern         ...............  25,750 (0.45)/
                                dalli.                                                                  California.                       17,954
Harbor seal..................  Phoca vitulina..  California......  ................  ................  Southern         ...............  30,968 (NA)/
                                                                                                        California.                       27,348
Hawaiian monk seal...........  Neomonachus       Hawaii..........  Strategic,        Endangered......  Hawaii.........  ...............  1,351 (0.03)/
                                schauinslandi.                      Depleted.                                                             1,325
Northern elephant seal.......  Mirounga          California......  ................  ................  Southern         ...............  179,000 (NA)/
                                angustirostris.                                                         California.                       81,368
California sea lion..........  Zalophus          U.S. Stock......  ................  ................  Southern         ...............  257,606 (NA)/
                                californianus.                                                          California.                       233,515
Guadalupe fur seal...........  Arctocephalus     Mexico to         Strategic,        Threatened......  Southern         ...............  34,187 (NA)/
                                townsendi.        California.       Depleted.                           California.                       31,019
Northern fur seal............  Callorhinus       California......  ................  ................  Southern         ...............  14,050 (NA)/
                                ursinus.                                                                California.                       7,524
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered, Threatened. MMPA status: Strategic, Depleted. A dash (-) indicates that the species/stock is not
  listed under the ESA or designated as depleted/strategic under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-
  caused mortality exceeds potential biological removal (PBR) or which is determined to be declining and likely to be listed under the ESA within the
  foreseeable future. Any species or stock listed under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ The two humpback whale Distinct Population Segments (DPSs) making up the California/Oregon/Washington (CA/OR/WA) stock present in Southern
  California are the Mexico DPS, listed under the ESA as Threatened, and the Central America DPS, which is listed under the ESA as Endangered.
\4\ NSD--No stock designation. Rough-toothed dolphin has a range known to include the waters off Southern California, but there is no recognized stock
  or data available for the U.S West Coast.


[[Page 41849]]

Unusual Mortality Events (UMEs)

    An UME is defined under Section 410(6) of the MMPA as a stranding 
that is unexpected; involves a significant die-off of any marine mammal 
population; and demands immediate response. From 1991 to the present, 
there have been 17 formally recognized UMEs affecting marine mammals in 
California and Hawaii and involving species under NMFS' jurisdiction. 
Three UMEs with ongoing or recently closed investigations in the HSTT 
Study Area that inform our analysis are discussed below. The California 
sea lion UME in California was closed on May 6, 2020. The Guadalupe fur 
seal UME in California and the gray whale UME along the west coast of 
North America are active and involve ongoing investigations.
California Sea Lion UME
    From January 2013 through September 2016, a greater than expected 
number of young malnourished California sea lions (Zalophus 
californianus) stranded along the coast of California. Sea lions 
stranding from an early age (6-8 months old) through two years of age 
(hereafter referred to as juveniles) were consistently underweight 
without other disease processes detected. Of the 8,122 stranded 
juveniles attributed to the UME, 93 percent stranded alive (n=7,587, 
with 3,418 of these released after rehabilitation) and 7 percent 
(n=531) stranded dead. Several factors are hypothesized to have 
impacted the ability of nursing females and young sea lions to acquire 
adequate nutrition for successful pup rearing and juvenile growth. In 
late 2012, decreased anchovy and sardine recruitment (CalCOFI data, 
July 2013) may have led to nutritionally stressed adult females. 
Biotoxins were present at various times throughout the UME, and while 
they were not detected in the stranded juvenile sea lions (whose 
stomachs were empty at the time of stranding), biotoxins may have 
impacted the adult females' ability to support their dependent pups by 
affecting their cognitive function (e.g., navigation, behavior towards 
their offspring). Therefore, the role of biotoxins in this UME, via its 
possible impact on adult females' ability to support their pups, is 
unclear. The proposed primary cause of the UME was malnutrition of sea 
lion pups and yearlings due to ecological factors. These factors 
included shifts in distribution, abundance and/or quality of sea lion 
prey items around the Channel Island rookeries during critical sea lion 
life history events (nursing by adult females, and transitioning from 
milk to prey by young sea lions). These prey shifts were most likely 
driven by unusual oceanographic conditions at the time due to the 
``Warm Water Blob'' and El Ni[ntilde]o. This investigation closed on 
May 6, 2020. Please refer to: https://www.fisheries.noaa.gov/national/marine-life-distress/2013-2017-california-sea-lion-unusual-mortality-event-california for more information on this UME.
Guadalupe Fur Seal UME
    Increased strandings of Guadalupe fur seals began along the entire 
coast of California in January 2015 and were eight times higher than 
the historical average (approximately 10 seals/yr). Strandings have 
continued since 2015 and remained well above average through 2019. 
Numbers by year are as follows: 2015 (98), 2016 (76), 2017 (62), 2018 
(45), 2019 (116), 2020 (3 as of 3/6/2020). The total number of 
Guadalupe fur seals stranding in California from January 1, 2015, 
through March 6, 2020, in the UME is 400. While outside the HSTT Study 
Area, strandings of Guadalupe fur seals became elevated in the spring 
of 2019 in Washington and Oregon; subsequently, strandings for seals in 
these two states have been added to the UME starting from January 1, 
2019. The current total number of strandings in Washington and Oregon 
is 94 seals, including 91 in 2019 and 3 in 2020 as of March 6, 2020. 
Strandings are seasonal and generally peak in April through June of 
each year. The Guadalupe fur seal strandings have been mostly weaned 
pups and juveniles (1-2 years old) with both live and dead strandings 
occurring. Current findings from the majority of stranded animals 
include primary malnutrition with secondary bacterial and parasitic 
infections. The California portion of this UME was occurring in the 
same area as the 2013-2016 California sea lion UME. This investigation 
is ongoing. Please refer to: https://www.fisheries.noaa.gov/national/marine-life-distress/2015-2019-guadalupe-fur-seal-unusual-mortality-event-california for more information on this UME.
Gray Whale UME
    Since January 1, 2019, elevated gray whale strandings have occurred 
along the west coast of North America, from Mexico to Canada. As of 
March 13, 2020, there have been a total of 264 strandings along the 
coasts of the United States, Canada, and Mexico, with 129 of those 
strandings occurring along the U.S. coast. Of the strandings on the 
U.S. coast, 48 have occurred in Alaska, 35 in Washington, 6 in Oregon, 
and 40 in California. Partial necropsy examinations conducted on a 
subset of stranded whales have shown evidence of poor to thin body 
condition. As part of the UME investigation process, NOAA is assembling 
an independent team of scientists to coordinate with the Working Group 
on Marine Mammal Unusual Mortality Events to review the data collected, 
sample stranded whales, and determine the next steps for the 
investigation. Please refer to: https://www.fisheries.noaa.gov/national/marine-life-distress/2019-gray-whale-unusual-mortality-event-along-west-coast for more information on this UME.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    We provided a full discussion of the potential effects of the 
specified activities on marine mammals and their habitat in our 2018 
HSTT proposed and final rules. In the Potential Effects of Specified 
Activities on Marine Mammals and Their Habitat section of the 2018 HSTT 
proposed and final rules, NMFS provided a description of the ways 
marine mammals may be affected by the same activities that the Navy 
will be conducting during the seven-year period analyzed in this rule 
in the form of serious injury or mortality, physical trauma, sensory 
impairment (permanent and temporary threshold shifts and acoustic 
masking), physiological responses (particularly stress responses), 
behavioral disturbance, or habitat effects. Therefore, we do not repeat 
the information here, all of which remains current and applicable, but 
refer the reader to those rules and the 2018 HSTT FEIS/OEIS (Chapter 3, 
Section 3.7 Marine Mammals), which NMFS participated in the development 
of via our cooperating agency status and adopted to meet our National 
Environmental Policy Act (NEPA) requirements.
    NMFS has reviewed new relevant information from the scientific 
literature since publication of the 2018 HSTT final rule. Summaries of 
new scientific literature since publication of the 2018 HSTT final rule 
are presented below.
    Nachtigall et al. (2018) and Finneran (2018) describe the 
measurements of hearing sensitivity of multiple odontocete species 
(bottlenose dolphin, harbor porpoise, beluga, and false killer whale) 
when a relatively loud sound was preceded by a warning sound. These 
captive animals were shown to reduce hearing sensitivity when warned of 
an impending intense sound. Based on these experimental observations of 
captive animals, the authors suggest that wild animals may dampen their 
hearing

[[Page 41850]]

during prolonged exposures or if conditioned to anticipate intense 
sounds. Finneran (2018) recommends further investigation of the 
mechanisms of hearing sensitivity reduction in order to understand the 
implications for interpretation of existing TTS data obtained from 
captive animals, notably for considering TTS due to short duration, 
unpredictable exposures. No modification of the 2018 HSTT EIS/OEIS 
analysis of auditory impacts is necessary based on this research, as 
these findings suggest additional research is required to understand 
implications on TTS data, and the current auditory impact thresholds 
are based on best available data for both impulsive and non-impulsive 
exposures to marine mammals.
    Several publications described models developed to examine the 
long-term effects of environmental or anthropogenic disturbance of 
foraging on various life stages of selected species (sperm whale, 
Farmer et al. (2018); California sea lion, McHuron et al. (2018); and 
blue whale, Pirotta, et al. (2018a)). These models, taken into 
consideration with similar models described in the 2018 HSTT EIS/OEIS, 
continue to add to refinement to the approaches to the population 
consequences of disturbance (PCOD) framework. Such models also help 
identify what data inputs require further investigation. Pirotta et al. 
(2018b) provides a review of the PCOD framework with details on each 
step of the process and approaches to applying real data or simulations 
to achieve each step. As described in the 2018 HSTT EIS/OEIS, many of 
the inputs required by such models are not yet known for acoustic and 
explosive impacts. NMFS will continue to assess the applicability of 
population consequences models in our analyses.
    Southall et al. (2019a) evaluated Southall et al. (2007) and used 
updated scientific information to propose revised noise exposure 
criteria to predict onset of auditory effects in marine mammals (i.e., 
PTS and TTS onset). Southall et al. (2019a) note that the quantitative 
processes described and the resulting exposure criteria (i.e., 
thresholds and auditory weighting functions) are largely identical to 
those in Finneran (2016) and NOAA (2016 and 2018). However, they differ 
in that the Southall et al. (2019a) exposure criteria are more broadly 
applicable as they include all marine mammal species (rather than those 
only under NMFS jurisdiction) for all noise exposures (both in air and 
underwater for amphibious species), and that while the hearing group 
compositions are identical they renamed the hearing groups.
    In continued investigations of pinniped hearing, Kastelein et al. 
(2019a) exposed two female captive harbor seals to 6.5 kHz continuous, 
sinusoidal tones for 60 minutes (cumulative sound exposure levels 
(SELs) of 159-195 dB re: 1 [micro]Pa\2\s), then measured TTS using 
behavioral (psychoacoustic) methods at the center frequency of the 
fatiguing sound (6.5 kHz) and 0.5 and 1 octave above that frequency 
(9.2 and 13 kHz). Susceptibility to TTS was similar in both individuals 
tested. At cumulative SELs below 179 dB re: 1 [micro]Pa\2\s, maximum 
TTS was induced at the center frequency (6.5 kHz), and at cumulative 
SELs above 179 dB re: 1 [micro]Pa\2\s, maximum TTS was induced at 0.5 
octave above the center frequency (9.2 kHz). The highest TTSs were 
produced in the one-half octave band above the exposure frequency. Both 
seals recovered within 1-2 hours for up to 6 dB of TTS. One seal showed 
19 dB of TTS after a dB re: 1 [micro]Pa\2\s exposure and recovered 
within 24 hours. Overall, this study combined with previous work showed 
that for harbor seals, recovery times are consistent for similar-
magnitude TTS, regardless of the type of fatiguing sound exposure 
(impulsive, continuous noise band, or sinusoidal wave), and that 
susceptibility to TTS in the fatiguing frequency range tested (2.5-6.5 
kHz) varies little with hearing frequency. The two harbor seals in this 
study (and Kastelein et al., 2012) had similar susceptibility to TTS as 
the seal in Kastak et al. (2005). The authors note that more fatiguing 
sound frequencies need to be tested in harbor seals to produce equal 
TTS curves, for generating weighting functions that can be used to 
develop exposure criteria for broadband sounds in the marine 
environment (Houser et al., 2017).
    To determine the distances at which Helicopter Long Range Active 
Sonar (HELRAS) signals (~1.3-1.4 kHz) can be detected, Kastelein et al. 
(2019b) measured hearing thresholds using behavioral (psychoacoustic) 
techniques to simulated HELRAS signals in two captive harbor seals. 
Both seals showed similar thresholds (51 dB re: 1 [micro]Pa rms, 
approximately 4 dB lower than the detection thresholds for the same 
individuals in Kastelein et al., 2009) to previously obtained data for 
stimuli having the same center frequencies, which suggests that the 
harmonics present within HELRAS sources do not impact hearing threshold 
and that a tonal audiogram can be used to estimate the audibility of 
more complex narrow-band tonal signals in harbor seals.
    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 (likely 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.
    Recent studies on the behavioral responses of cetaceans to sonar 
examine and continue to demonstrate the importance of not only sound 
source parameters, but exposure context (e.g., behavioral state, 
presence of other animals and social relationships, prey abundance, 
distance to source, presence of vessels, environmental parameters) in 
determining or predicting a behavioral response.
     Kastelein et al. (2018) examined the role of sound 
pressure level (SPL) and duty cycle on the behavior of two captive 
harbor porpoises when exposed to simulated Navy mid-frequency sonar 
(53C, 3.5 to 4.1 kHz). Neither harbor porpoise responded to the low 
duty cycle (2.7 percent) at any of the five SPLs presented, even at the 
maximum received SPL (143 dB re: 1 [micro]Pa). At the higher duty cycle 
(96 percent), one porpoise responded by increasing his respiration rate 
at a received SPL of greater than or equal to 119 dB re: 1 [micro]Pa, 
and moved away from the transducer at a received SPL of 143 dB re: 1 
[micro]Pa. Kastelein et al. (2018) observed that at the same received 
SPL and duty cycle, harbor porpoises respond less to 53C sonar sounds 
than 1-2 kHz, 6-7 kHz, and 25 kHz sonar signals observed in previous 
studies, but noted that when examining behavioral responses it is 
important to take into account the spectrum and temporal structure of 
the

[[Page 41851]]

signal, the duty cycle, and the psychological interpretation by the 
animal.
     To investigate the effect of signal to noise ratio (SNR) 
on behavioral responses, Kastelein et al. (2019c) observed respiration 
rates (an indicator of behavioral response) of two captive harbor 
porpoises when exposed to simulated 30-minute playbacks of Navy mid-
frequency sonar (53C, 3.5 to 4.1 kHz, 96 percent duty cycle), in noise 
simulating sea state 6 conditions. No behavioral responses were 
observed when the porpoises were exposed to sonar signals at an SPL of 
117 dB re: 1 [micro]Pa (SNR equal to 49 dB re: 1 Hz). Both porpoises 
responded when exposed to sonar signals at an SPL of 122 dB re: 1 
[micro]Pa (SNR equal to 54 dB re: 1 Hz), however in quiet conditions 
one porpoise responded at similar levels (Kastelein et al. 2018), 
suggesting the behavioral responses of harbor porpoises to sonar 
signals are not affected in sea state 6 ambient noise conditions.
     To determine if sonar sounds with different harmonic 
contents and amplitude envelopes had different impacts on harbor 
porpoise behavior, Kastelein et al. (2019d) examined the behavioral 
responses of one male harbor porpoise to four different low-frequency 
HELRAS (1.33 to 1.43 kHz) sonar signals (1.25 s in duration, 107 dB re: 
1 [mu]Pa SPL). The sonar sounds with sensation levels of approximately 
21 dB (and 8 percent duty cycle) caused a very small displacement (mean 
increased distance of 0.11 m), slight increase in respiration rate, and 
a small increase in swimming speed, and these effects did not continue 
after the sound exposure ceased. The authors concluded that if 
porpoises at sea were exposed to sonar signals of similar SPLs, the 
effects would be expected to be minimal. The authors noted that harbor 
porpoises are relatively insensitive to low-frequency signals below 4 
kHz, however high SPL harmonics of low-frequency sonar sound sounds can 
impact the behavior of harbor porpoises. They suggest new sonar systems 
be designed to reduce the level of harmonics.
     In an effort to examine potential mitigation measures to 
reduce impacts of seismic airguns on harbor porpoises, Kastelein et al. 
(2019e) examined the effect of a bubble screen on behavioral responses 
of two captive harbor porpoises exposed to airgun sounds. The bubble 
screen reduced the transmission of high-frequency airgun sounds by 20-
30 dB above 250 Hz, however the broadband SELs-s was only ~3 dB lower 
when the bubble screen was present. The harbor porpoises responded 
differently to the airgun sounds, with one being more responsive than 
the other. When the bubble screen was deployed neither individual 
responded to the airgun sounds, supporting the hypothesis that the 
frequency content of impulsive sounds is an important factor in 
behavioral responses of harbor porpoises. The authors suggest that 
small bubble screens, such as those tested in this study, could be an 
important tool in improving living conditions for captive harbor 
porpoises by reducing background noise levels.
     Kastelein et al. (2019f) examined fish catching efficiency 
in two captive harbor porpoises exposed to pile-driving playback sound 
(single strike exposure levels between 125 and 143 dB re: 1 [mu]Pa\2\s) 
and ambient (quiet) sound. They observed substantial individual 
variation in responses between the two harbor porpoises, with no change 
in fish catch success in one porpoise and decline in fish-catch success 
and trial termination in the second porpoise. These results suggest 
that high-amplitude pile driving sounds may negatively affect foraging 
behavior in some harbor porpoises. However, additional information is 
needed to determine the role of individual differences in responses to 
sound, termination rates, and fish-catching success to accurately 
estimate and quantify potential impacts.
     Wensveen et al. (2019) examined the role of sound source 
(simulated sonar pulses) distance and received level in northern 
bottlenose whales in an environment without frequent sonar activity 
using multi-scaled controlled exposure experiments. They observed 
behavioral avoidance of the sound source over a wide range of distances 
(0.8-28 km) and estimated avoidance thresholds ranging from modeled 
received SPLs of 117-126 dB re: 1 [micro]Pa as described by von Benda-
Beckmann et al. (2019). The behavioral response characteristics and 
avoidance thresholds were comparable to those previously observed in 
beaked whale studies; however, they did not observe an effect of 
distance on behavioral response and found that onset and intensity of 
behavioral response were better predicted by received SPL.
     Joyce et al. (2019) presented movement and dive behavior 
data from seven Blainville's beaked whales that were satellite tagged 
prior to naval sonar exercises using mid-frequency active sonar (MFAS, 
3-8 kHz) at the Atlantic Undersea Test and Evaluation Center (AUTEC) in 
the Bahamas. Five of the seven tagged were displaced 28-68 km after the 
onset of sonar exposure and returned to the AUTEC range 2-4 days after 
exercises ended. Three of the individuals for which modeled received 
SPLs were available during this movement showed declining received SPLs 
from initial maxima of 145-172 dB re: 1 [mu]Pa to maxima of 70-150 dB 
re: 1 [mu]Pa after displacements. Tagged individuals exhibited a 
continuation of deep diving activity consistent with foraging during 
MFAS exposure periods, but data also suggested that time spent on deep 
dives during initial exposure periods was reduced. These findings 
provide additional data for ongoing Population Consequences of Acoustic 
Disturbance assessments of disturbance as authors note that previous 
studies have suggested foraging dives may be lost in response to MFAS 
exposure, which could cause a decrease in energy intake and have 
potential effects on vital parameters. The data presented by Joyce et 
al. (2019) support the initial potential loss of foraging time, however 
they also suggest that Blainville's beaked whales may have the ability 
to partially compensate for this loss (assuming they have ample 
recovery times between dives) by increasing time spent at foraging 
depths following displacement.
     When conducting controlled exposure experiments on blue 
whales, 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. 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). Blue whale response did not follow a simple exposure-
response model based on received sound exposure level.
     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).

[[Page 41852]]

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]Pa2 (134 dB re: 1 [mu]Pa2s) and less 
than 2 km of 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)'').
     In a review of the previously published data (considered 
in the 2018 HSTT final rule and 2018 HSTT EIS/OEIS analysis) on the 
potential impacts of sonar on beaked whales, Bernaldo de Quir[oacute]s 
et al. (2019) suggested that the effect of mid-frequency active sonar 
on beaked whales varies among individuals or populations, and that 
predisposing conditions such as previous exposure to sonar and 
individual health risk factors may contribute to individual outcomes 
(such as decompression sickness).
     In an effort to improve estimates of behavioral responses 
to anthropogenic sound, Tyack and Thomas (2019) compared the approach 
of using a single threshold to newly developed dose-response functions. 
They demonstrated that the common approach of selecting the threshold 
at which half of the animals respond (RLp50) underestimates the number 
of individuals impacted. They suggest using a dose-response function to 
derive more accurate estimates of animals impacted and to set a 
threshold (the Effective Response Level) that corrects issues with the 
RLp50 estimate. The authors note that the Navy has calculated estimates 
of marine mammal takes using methods similar to the ones they 
recommend. Those methods were used to estimate take for this rule (see 
the Technical Report ``Criteria and Thresholds for U.S. Navy Acoustic 
and Explosive Effects Analysis (Phase III)'').
     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. 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.
    Having considered this information, and information provided in 
public comments on the 2019 HSTT 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 2018 HSTT proposed and final rules, 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.

Estimated Take of Marine Mammals

    This section indicates the number of takes that NMFS is 
authorizing, which are based on the amount of take that NMFS 
anticipates could occur or is likely to occur, depending on the type of 
take and the methods used to estimate it, as described below. NMFS 
coordinated closely with the Navy in the development of their 
incidental take applications, and agrees that the methods the Navy has 
put forth described herein and in the 2018 HSTT proposed and final 
rules 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. The number and type of 
incidental takes that could occur or are likely to occur annually 
remain identical to those authorized in the 2018 HSTT regulations.
    Takes are predominantly in the form of harassment, but a small 
number of serious injuries or mortalities are also authorized. 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, 
air guns, pile driving, 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. No more than 13 
serious injuries or mortalities (eight short-beaked common dolphins and 
five California sea lions over the seven-year period) are estimated as 
a result of exposure to explosive training and testing activities. 
Lastly, no more than three serious injuries or mortalities total (over 
the seven-year period) of mysticetes (except for sei whales, minke 
whales, Bryde's whales, Central North Pacific stock of blue whales, 
Hawaii stock of fin whales, and Western North Pacific stock of gray 
whales) and the Hawaii stock of sperm whales could occur through vessel 
collisions. Although we analyze the impacts of these potential serious 
injuries or mortalities that are authorized, the required mitigation 
and monitoring measures are expected to minimize the likelihood that 
ship strike or these high-level explosive exposures (and the associated 
serious injury or mortality) actually occur.
    Generally speaking, for acoustic impacts we estimate the amount and

[[Page 41853]]

type of harassment by considering: (1) Acoustic thresholds above which 
NMFS believes the best available science indicates marine mammals will 
be taken by behavioral 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) and the number of days of 
activities or events.

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 permanent threshold shift (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 
new behavioral Level B harassment thresholds have been refined here to 
better consider the best available science (e.g., incorporating both 
received level and distance), they also still, accordingly, 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 Level B 
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 Level B 
harassment thresholds are the most appropriate method for predicting 
behavioral Level B harassment given the best available science and the 
associated uncertainty.
    We described these acoustic thresholds and the methods used to 
determine thresholds, none of which have changed, in detail in the 
Acoustic Thresholds section of the 2018 HSTT final rule; please see the 
2018 HSTT final rule for detailed information.

Navy's Acoustic Effects Model

    The Navy proposed no changes to the Acoustic Effects Model as 
described in the 2018 HSTT final rule and there is no new information 
that would affect the applicability or validity of the model. Please 
see the 2018 HSTT final rule and Appendix E of the 2018 HSTT FEIS/OEIS 
for detailed information.

Range to Effects

    The Navy proposed no changes from the 2018 HSTT final rule to the 
type and nature of the specified activities to be conducted during the 
seven-year period analyzed in this final rule, including equipment and 
sources used and exercises conducted. There is also no new information 
that would affect the applicability or validity of the ranges to 
effects previously analyzed for these activities. Therefore, the ranges 
to effects in this final rule are identical to those described and 
analyzed in the 2018 HSTT final rule, including received sound levels 
that may cause onset of significant behavioral response and TTS and PTS 
in hearing for each source type or explosives that may cause non-
auditory injury. Please see the Range to Effects section and Tables 24 
through 40 of the 2018 HSTT final rule for detailed information.

Marine Mammal Density

    The Navy proposed no changes to the methods used to estimate marine 
mammal density described in the 2018 HSTT final rule and there is no 
new information that would affect the applicability or validity of 
these methods. Please see the 2018 HSTT final rule for detailed 
information.

Take Requests

    As in the 2018 HSTT final rule, in its 2019 application, the Navy 
determined that the three 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 NMFS 
agrees that the following stressors have the potential to result in 
takes of marine mammals from the Navy's planned activities:
     Acoustics (sonar and other transducers; air guns; pile 
driving/extraction);
     Explosives (explosive shock wave and sound, assumed to 
encompass the risk due to fragmentation); and
     Vessel strike.
    NMFS reviewed and agrees with the Navy's conclusion that acoustic 
and explosive sources have the potential to result in incidental takes 
of marine mammals by harassment, serious injury, or mortality. NMFS 
carefully reviewed the Navy's analysis and conducted its own analysis 
of vessel strikes, determining that the likelihood of any particular 
species of large whale being struck is quite low. Nonetheless, NMFS 
agrees that vessel strikes have the potential to result in incidental 
take from serious injury or mortality for certain species of large 
whales and the Navy specifically requested coverage for these species. 
Therefore, the likelihood of vessel strikes, and later the effects of 
the incidental take that is being authorized, has been fully analyzed 
and is described below.
    Regarding the quantification of expected takes from acoustic and 
explosive sources (by Level A and Level B harassment, as well as 
mortality resulting from exposure to explosives), the number of takes 
are based directly on the level of activities (days, hours, counts, 
etc., of different activities and events) in a given year. In the 2018 
HSTT final rule, take estimates across the five-years were based on the 
Navy conducting three years of a representative level of activity and 
two years of maximum level of activity. Consistent with the pattern set 
forth in the 2017 Navy application, the 2018 HSTT FEIS/OEIS, and the 
2018 HSTT final rule, the Navy included one additional representative 
year and one additional maximum year to determine the predicted take 
numbers in this rule. Specifically, as in the 2018 HSTT final rule, the 
Navy uses the maximum annual level to calculate annual takes (which 
would remain identical to what was determined in the 2018 HSTT final 
rule), and the sum of all years (four representative and three maximum) 
to calculate the seven-year totals for this rule.
    The quantitative analysis process used for the 2018 HSTT FEIS/OEIS 
and the 2017 and 2019 Navy applications to estimate potential exposures 
to marine mammals resulting from acoustic and explosive stressors is 
detailed in the technical report titled ``Quantifying

[[Page 41854]]

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 
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. Where the analysis indicates mitigation 
would effectively reduce risk, the model-estimated PTS 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 mitigation, see the 2017 Navy application and 
the Take Requests section of the 2018 HSTT final rule. The extent to 
which the mitigation areas reduce impacts on the affected species and 
stocks is addressed separately in the Analysis and Negligible Impact 
Determination sections of this rule and the 2018 HSTT final rule.
    No changes have been made to the quantitative analysis process to 
estimate potential exposures to marine mammals resulting from acoustic 
and explosive stressors and calculate take estimates. In addition, 
there is no new information that would call into question the validity 
of the Navy's quantitative analysis process. Please see the documents 
described in the paragraph above, the 2018 HSTT proposed rule, and the 
2018 HSTT final rule for detailed descriptions of these analyses. In 
summary, we believe the Navy's methods, including the method for 
incorporating mitigation and avoidance, are the most appropriate 
methods for predicting PTS, tissue damage, TTS, and behavioral 
disruption. 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 PTS, tissue damage, 
TTS, or behavioral disruption.
Summary of Authorized 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 estimates 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 2019 Navy application. Annual takes (based 
on the maximum number of activities that could occur per 12-month 
period) from the use of acoustic and explosive sources are identical to 
those presented in Tables 41 and 42 and in the Explosives subsection of 
the Take Requests section of the 2018 HSTT final rule. The 2019 Navy 
application also includes the Navy's take estimate and request for 
vessel strikes due to vessel movement in the HSTT Study Area. The No 
Stock Designation stock of rough-toothed was modeled by the Navy and 
estimated to have 0 takes of any type from any activity source. 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 as well as the 
incidental takes by serious injury or mortality from explosives 
requested for authorization are the maximum number reasonably expected 
to occur. NMFS also agrees that the takes by serious injury or 
mortality as a result of vessel strikes could occur. The total amount 
of estimated incidental take from acoustic and explosive sources over 
the total seven-year period covered by the 2019 Navy application is 
less than the annual total multiplied by seven, because although the 
annual estimates are based on the maximum number of activities per year 
and therefore the maximum possible estimated takes, the seven-year 
total take estimates are based on the sum of three maximum years and 
four representative years. Not all activities occur every year. Some 
activities would occur multiple times within a year, and some 
activities would occur only a few times over the course of the seven-
year period. Using seven years of the maximum number of activities each 
year would vastly overestimate the amount of incidental take that would 
occur over the seven-year period where the Navy knows that it will not 
conduct the maximum number of activities each and every year for the 
seven years.
Authorized Harassment Take from Training Activities
    For training activities, Table 11 summarizes the Navy's take 
estimate and request and the maximum amount and type of Level A 
harassment and Level B harassment for the seven-year period covered by 
the 2019 Navy application that NMFS concurs is reasonably expected to 
occur by species or stock, and is therefore authorized. For the 
authorized amount and type of Level A harassment and Level B harassment 
annually, see Table 41 in the 2018 HSTT final rule. Note that take by 
Level B harassment includes both behavioral disruption and TTS. Navy 
Figures 6-12 through 6-50 in Section 6 of the 2017 Navy application 
illustrate the comparative amounts of TTS and behavioral disruption 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 11--Seven-Year Total Species- And Stock-Specific Take Authorized From Acoustic and Explosive Sound Source
                                       Effects for all Training Activities
----------------------------------------------------------------------------------------------------------------
                                                                                           7-year total
                    Species                                   Stock              -------------------------------
                                                                                      Level B         Level A
----------------------------------------------------------------------------------------------------------------
Blue whale *..................................  Central North Pacific...........             205               0
                                                Eastern North Pacific...........           7,116               6
Bryde's whale [dagger]........................  Eastern Tropical Pacific........             167               0
                                                Hawaiian [dagger]...............             631               0
Fin whale *...................................  CA/OR/WA........................           7,731               0
                                                Hawaiian........................             197               0
Humpback whale [dagger].......................  CA/OR/WA [dagger]...............           7,962               7

[[Page 41855]]

 
                                                Central North Pacific...........          34,437              12
Minke whale...................................  CA/OR/WA........................           4,119               7
                                                Hawaiian........................          20,237               6
Sei whale *...................................  Eastern North Pacific...........             333               0
                                                Hawaiian........................             677               0
Gray whale [dagger]...........................  Eastern North Pacific...........          16,703              27
                                                Western North Pacific [dagger]..              19               0
Sperm whale *.................................  CA/OR/WA........................           8,834               0
                                                Hawaiian........................          10,341               0
Dwarf sperm whale.............................  Hawaiian........................          84,232             215
Pygmy sperm whale.............................  Hawaiian........................          33,431              94
Kogia whales..................................  CA/OR/WA........................          38,609             149
Baird's beaked whale..........................  CA/OR/WA........................           8,524               0
Blainville's beaked whale.....................  Hawaiian........................          23,491               0
Cuvier's beaked whale.........................  CA/OR/WA........................          47,178               0
                                                Hawaiian........................           7,898               0
Longman's beaked whale........................  Hawaiian........................          82,293               0
Mesoplodon species (beaked whale guild).......  CA/OR/WA........................          25,404               0
Bottlenose dolphin............................  California Coastal..............           1,295               0
                                                CA/OR & WAOffshore..............         201,619              13
                                                Hawaiian Pelagic................          13,080               0
                                                Kauai & Niihau..................             500               0
                                                Oahu............................          57,288              10
                                                4-Island........................           1,052               0
                                                Hawaii..........................             291               0
False killer whale [dagger]...................  Hawaii Pelagic..................           4,353               0
                                                Main Hawaiian Islands Insular              2,710               0
                                                 [dagger].
                                                Northwestern Hawaiian Islands...           1,585               0
Fraser's dolphin..............................  Hawaiian........................         177,198               4
Killer whale..................................  Eastern North Pacific Offshore..             460               0
                                                Eastern North Pacific Transient/             855               0
                                                 West Coast Transient.
                                                Hawaiian........................             513               0
Long-beaked common dolphin....................  California......................         784,965              99
Melon-headed whale............................  Hawaiian Islands................          14,137               0
                                                Kohala Resident.................           1,278               0
Northern right whale dolphin..................  CA/OR/WA........................         357,001              57
Pacific white-sided dolphin...................  CA/OR/WA........................         274,892              19
Pantropical spotted dolphin...................  Hawaii Island...................          17,739               0
                                                Hawaii Pelagic..................          42,318               0
                                                Oahu............................          28,860               0
                                                4-Island........................           1,816               0
Pygmy killer whale............................  Hawaiian........................          35,531               0
                                                Tropical........................           2,977               0
Risso's dolphin...............................  CA/OR/WA........................         477,389              45
                                                Hawaiian........................          40,800               0
Rough-toothed dolphin.........................  Hawaiian........................          26,769               0
                                                NSD \1\.........................               0               0
Short-beaked common dolphin...................  CA/OR/WA........................       5,875,431             307
Short-finned pilot whale......................  CA/OR/WA........................           6,341               6
                                                Hawaiian........................          53,627               0
Spinner dolphin...............................  Hawaii Island...................             609               0
                                                Hawaii Pelagic..................          18,870               0
                                                Kauai & Niihau..................           1,961               0
                                                Oahu & 4-Island.................          10,424               8
Striped dolphin...............................  CA/OR/WA........................         777,001               5
                                                Hawaiian........................          32,806               0
Dall's porpoise...............................  CA/OR/WA........................         171,250             894
California sea lion...........................  U.S.............................         460,145             629
Guadalupe fur seal*...........................  Mexico..........................           3,342               0
Northern fur seal.............................  California......................          62,138               0
Harbor seal...................................  California......................          19,214              48
Hawaiian monk seal*...........................  Hawaiian........................             938               5
Northern elephant seal........................  California......................         241,277             490
----------------------------------------------------------------------------------------------------------------
* ESA-listed species (all stocks) within the HSTT Study Area.
[dagger] Only designated stocks are ESA-listed.
\1\ NSD: No stock designation.


[[Page 41856]]

Authorized Harassment Take From Testing Activities
    For testing activities, Table 12 summarizes the Navy's take 
estimate and request and the maximum amount and type of Level A 
harassment and Level B harassment for the seven-year period covered by 
the 2019 Navy application that NMFS concurs is reasonably expected to 
occur by species or stock, and is therefore authorized. For the 
estimated amount and type of Level A harassment and Level B harassment 
annually, see Table 42 in the 2018 HSTT final rule. Note that take by 
Level B harassment includes both behavioral disruption and TTS. Navy 
Figures 6-12 through 6-50 in Section 6 of the 2017 Navy application 
illustrate the comparative amounts of TTS and behavioral disruption 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 12--Seven-Year Total Species and Stock-Specific Take Authorized From Acoustic and Explosive Sound Source
                                       Effects for all Testing Activities
----------------------------------------------------------------------------------------------------------------
                                                                                           7-year total
                    Species                                   Stock              -------------------------------
                                                                                      Level B         Level A
----------------------------------------------------------------------------------------------------------------
Blue whale *..................................  Central North Pacific...........              93               0
                                                Eastern North Pacific...........           5,679               0
Bryde's whale [dagger]........................  Eastern Tropical Pacific........              97               0
                                                Hawaiian [dagger]...............             278               0
Fin whale *...................................  CA/OR/WA........................           6,662               7
                                                Hawaiian........................             108               0
Humpback whale [dagger].......................  CA/OR/WA[dagger]................           4,961               0
                                                Central North Pacific...........          23,750              19
Minke whale...................................  CA/OR/WA........................           1,855               0
                                                Hawaiian........................           9,822               7
Sei whale *...................................  Eastern North Pacific...........             178               0
                                                Hawaiian........................             329               0
Gray whale [dagger]...........................  Eastern North Pacific...........          13,077               9
                                                Western North Pacific [dagger]..              15               0
Sperm whale *.................................  CA/OR/WA........................           7,409               0
                                                Hawaiian........................           5,269               0
Dwarf sperm whale.............................  Hawaiian........................          43,374             197
Pygmy sperm whale.............................  Hawaiian........................          17,396              83
Kogia whales..................................  CA/OR/WA........................          20,766              94
Baird's beaked whale..........................  CA/OR/WA........................           4,841               0
Blainville's beaked whale.....................  Hawaiian........................          11,455               0
Cuvier's beaked whale.........................  CA/OR/WA........................          30,180              28
                                                Hawaiian........................           3,784               0
Longman's beaked whale........................  Hawaiian........................          41,965               0
Mesoplodon species (beaked whale guild).......  CA/OR/WA........................          16,383              15
Bottlenose dolphin............................  California Coastal..............          11,158               0
                                                CA/OR & WA Offshore.............         158,700               8
                                                Hawaiian Pelagic................           8,469               0
                                                Kauai & Niihau..................           3,091               0
                                                Oahu............................           3,230               0
                                                4-Island........................           1,129               0
                                                Hawaii..........................             260               0
False killer whale [dagger]...................  Hawaii Pelagic..................           2,287               0
                                                Main Hawaiian Islands Insular              1,256               0
                                                 [dagger].
                                                Northwestern Hawaiian Islands...             837               0
Fraser's dolphin..............................  Hawaiian........................          85,193               9
Killer whale..................................  Eastern North Pacific Offshore..             236               0
                                                Eastern North Pacific Transient/             438               0
                                                 West Coast Transient.
                                                Hawaiian........................             279               0
Long-beaked common dolphin....................  California......................         805,063              34
Melon-headed whale............................  Hawaiian Islands................           7,678               0
                                                Kohala Resident.................           1,119               0
Northern right whale dolphin..................  CA/OR/WA........................         280,066              22
Pacific white-sided dolphin...................  CA/OR/WA........................         213,380              14
Pantropical spotted dolphin...................  Hawaii Island...................           9,568               0
                                                Hawaii Pelagic..................          24,805               0
                                                Oahu............................           1,349               0
                                                4-Island........................           2,513               0
Pygmy killer whale............................  Hawaiian........................          18,347               0
                                                Tropical........................           1,928               0
Risso's dolphin...............................  CA/OR/WA........................         339,334              24
                                                Hawaiian........................          19,027               0
Rough-toothed dolphin.........................  Hawaiian........................          14,851               0
                                                NSD \1\.........................               0               0
Short-beaked common dolphin...................  CA/OR/WA........................       3,795,732             304
Short-finned pilot whale......................  CA/OR/WA........................           6,253               0
                                                Hawaiian........................          29,269               0
Spinner dolphin...............................  Hawaii Island...................           1,394               0

[[Page 41857]]

 
                                                Hawaii Pelagic..................           9,534               0
                                                Kauai & Niihau..................           9,277               0
                                                Oahu & 4-Island.................           1,987               0
Striped dolphin...............................  CA/OR/WA........................         371,328              20
                                                Hawaiian........................          16,270               0
Dall's porpoise...............................  CA/OR/WA........................         115,353             478
California sea lion...........................  U.S.............................         334,332              36
Guadalupe fur seal *..........................  Mexico..........................           6,167               0
Northern fur seal.............................  California......................          36,921               7
Harbor seal...................................  California......................          15,898              12
Hawaiian monk seal *..........................  Hawaiian........................             372               0
Northern elephant seal........................  California......................         151,754             187
----------------------------------------------------------------------------------------------------------------
* ESA-listed species (all stocks) within the HSTT Study Area.
[dagger] Only designated stocks are ESA-listed.
\1\ NSD: No stock designation.

Authorized Take From Vessel Strikes and Explosives by Serious Injury or 
Mortality

Vessel Strike

    Vessel strikes from commercial, recreational, and military vessels 
are known to affect large whales and have resulted in serious injury 
and occasional fatalities to cetaceans (Berman-Kowalewski et al., 2010; 
Calambokidis, 2012; Douglas et al., 2008; Laggner 2009; Lammers et al., 
2003). Records of collisions date back to the early 17th century, and 
the worldwide number of collisions appears to have increased steadily 
during recent decades (Laist et al., 2001; Ritter 2012).
    Numerous studies of interactions between surface vessels and marine 
mammals have demonstrated that free-ranging marine mammals often, but 
not always (e.g., McKenna et al., 2015), engage in avoidance behavior 
when surface vessels move toward them. It is not clear whether these 
responses are caused by the physical presence of a surface vessel, the 
underwater noise generated by the vessel, or an interaction between the 
two (Amaral and Carlson, 2005; Au and Green, 2000; Bain et al., 2006; 
Bauer 1986; Bejder et al., 1999; Bejder and Lusseau, 2008; Bejder et 
al., 2009; Bryant et al., 1984; Corkeron, 1995; Erbe, 2002; 
F[eacute]lix, 2001; Goodwin and Cotton, 2004; Lemon et al., 2006; 
Lusseau, 2003; Lusseau, 2006; Magalhaes et al., 2002; Nowacek et al., 
2001; Richter et al., 2003; Scheidat et al., 2004; Simmonds, 2005; 
Watkins, 1986; Williams et al., 2002; Wursig et al., 1998). Several 
authors suggest that the noise generated during motion is probably an 
important factor (Blane and Jaakson, 1994; Evans et al., 1992; Evans et 
al., 1994). Water disturbance may also be a factor. These studies 
suggest that the behavioral responses of marine mammals to surface 
vessels are similar to their behavioral responses to predators. 
Avoidance behavior is expected to be even stronger in the subset of 
instances during which the Navy is conducting training or testing 
activities using active sonar or explosives.
    The marine mammals most vulnerable to vessel strikes are those that 
spend extended periods of time at the surface in order to restore 
oxygen levels within their tissues after deep dives (e.g., sperm 
whales). In addition, some baleen whales seem generally unresponsive to 
vessel sound, making them more susceptible to vessel collisions 
(Nowacek et al., 2004). These species are primarily large, slow moving 
whales.
    Some researchers have suggested the relative risk of a vessel 
strike can be assessed as a function of animal density and the 
magnitude of vessel traffic (e.g., Fonnesbeck et al., 2008; Vanderlaan 
et al., 2008). Differences among vessel types also influence the 
probability of a vessel strike. The ability of any ship to detect a 
marine mammal and avoid a collision depends on a variety of factors, 
including environmental conditions, ship design, size, speed, and 
ability and number of personnel observing, as well as the behavior of 
the animal. Vessel speed, size, and mass are all important factors in 
determining if injury or death of a marine mammal is likely due to a 
vessel strike. For large vessels, speed and angle of approach can 
influence the severity of a strike. For example, Vanderlaan and Taggart 
(2007) found that between vessel speeds of 8.6 and 15 knots, the 
probability that a vessel strike is lethal increases from 0.21 to 0.79. 
Large whales also do not have to be at the water's surface to be 
struck. Silber et al. (2010) found when a whale is below the surface 
(about one to two times the vessel draft), there is likely to be a 
pronounced propeller suction effect. This suction effect may draw the 
whale into the hull of the ship, increasing the probability of 
propeller strikes.
    There are some key differences between the operation of military 
and non-military vessels, which make the likelihood of a military 
vessel striking a whale lower than some other vessels (e.g., commercial 
merchant vessels). Key differences include:
     Many military ships have their bridges positioned closer 
to the bow, offering better visibility ahead of the ship (compared to a 
commercial merchant vessel).
     There are often aircraft associated with the training or 
testing activity (which can serve as Lookouts), which can more readily 
detect cetaceans in the vicinity of a vessel or ahead of a vessel's 
present course before crew on the vessel would be able to detect them.
     Military ships are generally more maneuverable than 
commercial merchant vessels, and if cetaceans are spotted in the path 
of the ship, could be capable of changing course more quickly.
     The crew size on military vessels is generally larger than 
merchant ships, allowing for stationing more trained Lookouts on the 
bridge. At all times when vessels are underway, trained Lookouts and 
bridge navigation teams are used to detect objects on the surface of 
the water ahead of the ship, including cetaceans. Additional Lookouts, 
beyond those already stationed on the bridge and on navigation teams, 
are positioned

[[Page 41858]]

as Lookouts during some training events.
     When submerged, submarines are generally slow moving (to 
avoid detection) and therefore marine mammals at depth with a submarine 
are likely able to avoid collision with the submarine. When a submarine 
is transiting on the surface, there are Lookouts serving the same 
function as they do on surface ships.
    Vessel strike to marine mammals is not associated with any specific 
training or testing activity but is rather an extremely limited and 
sporadic, but possible, accidental result of Navy vessel movement 
within the HSTT Study Area or while in transit.
    There have been two recorded Navy vessel strikes of large whales in 
the HSTT Study Area from 2009 through 2018, the period in which the 
Navy began implementing effective mitigation measures to reduce the 
likelihood of vessel strikes. Both strikes occurred in 2009 and both 
were to fin whales. In order to account for the accidental nature of 
vessel strikes to large whales in general, and the potential risk from 
any vessel movement within the HSTT Study Area within the seven-year 
period in particular, the Navy requested incidental takes based on 
probabilities derived from a Poisson distribution using ship strike 
data between 2009-2018 in the HSTT Study Area (the time period from 
when current mitigations were instituted until the Navy conducted the 
analysis for the 2019 Navy application), as well as historical at-sea 
days in the HSTT Study Area from 2009-2018 and estimated potential at-
sea days for the period from 2018 to 2025 covered by the requested 
regulations. This distribution predicted the probabilities of a 
specific number of strikes (n=0, 1, 2, etc.) over the period from 2018 
to 2025. The analysis for the period of 2018 to 2023 is described in 
detail in Chapter 6 of the 2017 Navy application and has been updated 
for this seven-year rulemaking.
    For the same reasons listed above, describing why a Navy vessel 
strike is comparatively unlikely, it is highly unlikely that a Navy 
vessel would strike a whale, dolphin, porpoise, or pinniped without 
detecting it and, accordingly, NMFS is confident that the Navy's 
reported strikes are accurate and appropriate for use in the analysis. 
Specifically, Navy ships have multiple Lookouts, including on the 
forward part of the ship that can visually detect a hit animal, in the 
unlikely event ship personnel do not feel the strike. Unlike the 
situation for non-Navy ships engaged in commercial activities, NMFS and 
the Navy have no evidence that the Navy has struck a whale and not 
detected it. Navy's strict internal procedures and mitigation 
requirements 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.
    The Navy used the two fin whale strikes in their calculations to 
determine the number of strikes likely to result from their activities 
(although worldwide strike information, from all Navy activities and 
other sources, was used to inform the species that may be struck) and 
evaluated data beginning in 2009, as that was the start of the Navy's 
Marine Species Awareness Training and adoption of additional mitigation 
measures to address ship strike, which will remain in place along with 
additional mitigation measures during the seven years of this rule. The 
probability analysis concluded that there was a 22 percent chance that 
no whales would be struck by Navy vessels over the seven-year period, 
and a 33, 25, 13, and 5 percent chance that one, two, three, or four 
whales, respectively, would be struck over the seven-year period. All 
other alternatives (i.e. one, two, three, or more whales) represent a 
78 percent chance that at least one whale would be struck over the 
seven-year period. Therefore, the Navy estimates, and NMFS agrees, that 
there is some probability that the Navy could strike, and take by 
serious injury or mortality, up to three large whales incidental to 
training and testing activities within the HSTT Study Area over the 
course of the seven years.
    The probability of the Navy striking up to three large whales over 
the seven-year period (which is a 13 percent chance) as analyzed for 
this final rule using updated Navy vessel strike data and at-sea days 
is very close to the probability of the Navy striking up to three large 
whales over five years (which was a 10 percent chance). As the 
probability of striking three large whales does not differ 
significantly from the 2018 HSTT final rule, and the probability of 
striking four large whales over seven years remains very low to the 
point of being unlikely (less than 5 percent), the Navy has requested, 
and we are authorizing no change in the number of takes by serious 
injury or mortality due to vessel strikes.
    Small whales, delphinids, porpoises, and pinnipeds are not expected 
to be struck by Navy vessels. In addition to the reasons listed above 
that make it unlikely that the Navy will hit a large whale (more 
maneuverable ships, larger crew, etc.), the following are the 
additional reasons that vessel strike of dolphins, small whales, 
porpoises, and pinnipeds is considered very unlikely. Dating back more 
than 20 years and for as long as it has kept records, the Navy has no 
records of individuals of these groups being struck by a vessel as a 
result of Navy activities and, further, these species' smaller size and 
maneuverability make a strike unlikely. Also, NMFS has never received 
any reports from other authorized activities indicating that these 
species have been struck by vessels. Worldwide ship strike records show 
little evidence of strikes of these groups from the shipping sector and 
larger vessels, and the majority of the Navy's activities involving 
faster-moving vessels (that could be considered more likely to hit a 
marine mammal) are located in offshore areas where smaller delphinid, 
porpoise, and pinniped densities are lower. Based on this information, 
NMFS concurs with the Navy's assessment and recognizes the potential 
for incidental take by vessel strike of large whales only (i.e., no 
dolphins, small whales, porpoises, or pinnipeds) over the course of the 
seven-year regulations from training and testing activities as 
discussed further below.
    As noted in the 2018 HSTT proposed and final rules, in the 2017 
Navy application the Navy initially considered a weight of evidence 
approach that considered relative abundance, historical strike data 
over many years, and the overlap of Navy activities with the stock 
distribution in their request. NMFS and the Navy further discussed the 
available information and considered two factors in addition to those 
considered in the Navy's request: (1) The relative likelihood of 
hitting one stock versus another based on available strike data from 
all vessel types as denoted in the SARs and (2) whether the Navy has 
ever definitively struck an individual from a particular stock and, if 
so, how many times. For this seven-year rule, we have reconsidered 
these two factors and updated the analysis with the Navy's seven-year 
ship strike probability analysis and any new/updated ship strike data 
from the SARs.
    To address number (1) above, NMFS compiled information from NMFS' 
SARs on detected annual rates of large whale serious injury or 
mortality from vessel collisions (Table 13). The annual rates of large 
whale serious injury or mortality from vessel collisions from the SARs 
help inform the relative susceptibility of large whale species to

[[Page 41859]]

vessel strike in SOCAL and Hawaii as recorded systematically over the 
last five years (the period used for the SARs). We summed the annual 
rates of serious injury or mortality from vessel collisions as reported 
in the SARs, then divided each species' annual rate by this sum to get 
the proportion of strikes for each species/stock. To inform the 
likelihood of striking a particular species of large whale, we 
multiplied the proportion of strikes for each species by the 
probability of striking a whale (i.e., 78 percent, as described by the 
Navy's probability analysis above). We also estimated the percent 
likelihood of striking a particular species of large whale twice by 
squaring the value estimated for the probability of striking a 
particular species of whale once (i.e., generally, to calculate the 
probability of an event occurring twice, multiply the probability of 
the first event by the second). We note that these probabilities vary 
from year to year as the average annual mortality for a given five-year 
window in the SAR changes (and we include the annual averages from 2017 
and 2018 SARs in Table 13 to illustrate), however, over the years and 
through changing SARs, stocks tend to consistently maintain a 
relatively higher or relatively lower likelihood of being struck.
    The probabilities calculated as described above are then considered 
in combination with the information indicating the species that the 
Navy has definitively hit in the HSTT Study Area since 1991 (since they 
started tracking consistently), as well as the information originally 
considered by the Navy in their 2017 application, which includes 
relative abundance, total recorded strikes, and the overlay of all of 
this information with the Navy's Study Area. We note that for all of 
the take of species specifically denoted in Table 13 below, 19 percent 
of the individuals struck overall by any vessel type remained 
unidentified and 36 percent of those struck by the Navy (5 of 14 in the 
Pacific) remain unidentified. However, given the information on known 
species or stocks struck, the analysis below remains appropriate. We 
also note that Rockwood et al. (2017) modeled the likely vessel strike 
of blue whales, fin whales, and humpback whales on the U.S. West Coast 
(discussed in more detail in the Serious Injury or Mortality subsection 
of the Analysis and Negligible Impact Determination section), and those 
numbers help inform the relative likelihood that the Navy will hit 
those stocks.
    For each indicated stock, Table 13 includes the percent likelihood 
of hitting an individual whale once based on SAR data, total strikes 
from Navy vessels and from all other vessels, relative abundance, and 
modeled vessel strikes from Rockwood et al. (2017). The last column 
indicates the annual mortality that has the reasonable potential to 
occur and is authorized: Those stocks with one serious injury or 
mortality (M/SI) take authorized over the seven-year period of the rule 
are shaded lightly, while those with two M/SI takes that have the 
potential to occur and are authorized over the seven-year period of the 
rule are shaded more darkly.

[[Page 41860]]

[GRAPHIC] [TIFF OMITTED] TR10JY20.000

    Accordingly, stocks that have no record of ever having been struck 
by any vessel are considered unlikely to be struck by the Navy in the 
seven-year period of the rule. Stocks that have never been struck by 
the Navy, have rarely been struck by other vessels, and have a low 
percent likelihood based on the SAR calculation and a low relative 
abundance are also considered unlikely to be struck by the Navy during 
the seven years covered by this rule. We note that while vessel strike 
records have not differentiated between Eastern North Pacific and 
Western North Pacific gray whales, given their small population size 
and the comparative rarity with which individuals from the Western 
North Pacific stock are detected off the U.S. West Coast, it is highly 
unlikely that they would be

[[Page 41861]]

encountered, much less struck. This rules out all but six stocks.
    Three of the six stocks (CA/OR/WA stock of fin whale, Eastern North 
Pacific stock of gray whale, and Central North Pacific stock of 
humpback whale) are the only stocks to have been hit more than one time 
each by the Navy in the HSTT Study Area, have the three highest total 
strike records (21, 35, and 58 respectively), have three of the four 
highest percent likelihoods based on the SAR records, have three of the 
four significantly higher relative abundances, and have up to a 3.4 
percent likelihood of being struck twice based on NMFS' SAR calculation 
(not shown in Table 13, but proportional to percent likelihood of being 
struck once). Based on all of these factors, it is considered 
reasonably likely that these stocks could be struck twice during the 
seven-year rule.
    Based on the information summarized in Table 13, and the fact that 
there is the potential for up to three large whales to be struck, it is 
considered reasonably likely that one individual from the remaining 
three stocks could be one of the three whales struck. Sperm whales have 
only been struck a total of two times by any vessel type in the whole 
HSTT Study Area, however, the Navy struck a sperm whale once in Hawaii 
prior to 2009 and the relative abundance of sperm whales in Hawaii is 
the highest of any of the stocks present. Therefore, we consider it 
reasonably likely that the Hawaii stock of sperm whales could be struck 
once during the seven-year rule. The total strikes of Eastern North 
Pacific blue whales, the percent likelihood of striking one based on 
the SAR calculation, and their relative abundance can all be considered 
moderate compared to other stocks, and the Navy has struck one in the 
past prior to 2009 (with the likelihood of striking two based on the 
SAR calculation being below one percent). Therefore, we consider it 
reasonably likely that the Navy could strike one individual over the 
course of the seven-year rule. The Navy has not hit a humpback whale in 
the HSTT Study Area and the relative abundance of the CA/OR/WA stock is 
very low. However, a U.S. Coast Guard vessel escorting a Navy vessel 
struck a humpback whale in the Northwest (outside of the HSTT Study 
Area) and as a species, humpback whales have a moderate to high number 
of total strikes and percent likelihood of being struck. Although the 
likelihood of CA/OR/WA humpback whales being struck overall is moderate 
to high relative to other stocks, the distribution of the Mexico DPS 
versus the Central America DPS, as well as the distribution of overall 
vessel strikes inside versus outside of the SOCAL area (the majority 
are outside), supports the reasonable likelihood that the Navy could 
strike one individual humpback whale from the CA/OR/WA stock (not two), 
and that that individual would be highly likely to be from the Mexico 
DPS, as described below.
    Specifically, regarding the likelihood of striking a humpback whale 
from a particular DPS, as suggested in Wade et al. (2016), the 
probability of encountering (which is thereby applied to striking) 
humpback whales from each DPS in the CA/OR area is 89.6 percent and 
19.7 percent for the Mexico and Central America DPSs, respectively 
(note that these percentages reflect the upper limit of the 95 percent 
confidence interval to reduce the likelihood of underestimating take, 
and thereby do not total to 100). This suggests that the chance of 
striking a humpback whale from the Central America DPS is one tenth to 
one fifth of the overall chance of hitting a CA/OR/WA humpback whale in 
general in the SOCAL part of the HSTT Study Area, which in combination 
with the fact that no humpback whale has been struck in SOCAL makes it 
highly unlikely, and thereby no strikes of whales from the Central 
America DPS are anticipated or authorized. If a humpback whale were 
struck in SOCAL, it is likely it would be of the Mexico DPS. However, 
regarding the overall likelihood of striking a humpback whale at all 
and the likely number of times, we note that the majority of strikes of 
the CA/OR/WA humpback whale stock (i.e., the numbers reflected in Table 
13) take place outside of SOCAL. Whereas the comparative DPS numbers 
cited above apply in the California and Oregon feeding area and in the 
Washington and Southern British Columbia feeding area, Wade et al. 
(2016) suggest that 52.9, 41.9, and 14.7 percent of humpback whales 
encountered will come from the Hawaii, Mexico, and Central America 
DPSs, respectively. This means that the numbers in Table 13 indicating 
the overall strikes of CA/OR/WA humpback whales and SAR calculations 
based on average annual mortality over the last five years are actually 
lower than indicated for the Mexico DPS, which would only be a subset 
of those mortalities. Lastly, the Rockwood et al. paper supports a 
relative likelihood of 1:1:2 for striking blue whales, humpback whales, 
and fin whales off the U.S. West Coast, which supports the authorized 
take included in this rule, which is 1, 1, and 2, respectively over the 
seven-year period. For these reasons, one M/SI take of CA/OR/WA 
humpback whales, which would be expected to be of the Mexico DPS, could 
reasonably likely occur and is authorized.
    Accordingly, the Navy has requested, and NMFS authorizes, take by 
M/SI from vessel strike of up to two of any of the following species/
stocks in the seven-year period: Gray whale (Eastern North Pacific 
stock), fin whale (CA/OR/WA stock), humpback whale (Central North 
Pacific stock); and one of any of the following species/stocks in the 
seven-year period: Blue whale (Eastern North Pacific stock), humpback 
whale (CA/OR/WA stock, Mexico DPS), or sperm whale (Hawaii stock).
    As described above, the Navy analysis suggests, and NMFS analysis 
concurs, that vessel strikes to the stocks below are very unlikely to 
occur due to the stocks' relatively low occurrence in the HSTT Study 
Area, particularly in core HSTT training and testing subareas, and the 
fact that the stocks have not been struck by the Navy and are rarely, 
if ever, recorded struck by other vessels. Therefore, the Navy is not 
requesting lethal take authorization, and NMFS is not authorizing 
lethal take, for the following stocks: Bryde's whale (Eastern Tropical 
Pacific stock), Bryde's whale (Hawaii stock), humpback whale (CA/OR/WA 
stock, Central America DPS), minke whale (CA/OR/WA stock), minke whale 
(Hawaii stock), sei whale (Hawaii stock), sei whale (Eastern North 
Pacific stock), and sperm whale (CA/OR/WA stock).
    In conclusion, although it is generally unlikely that any whales 
will be struck in a year, based on the information and analysis above, 
NMFS anticipates that no more than three whales have the potential to 
be taken by M/SI over the seven-year period of the rule, and that those 
three whales may include no more than two of any of the following 
stocks: Gray whale (Eastern North Pacific stock), fin whale (CA/OR/WA 
stock), and humpback whale (Central North Pacific stock); and no more 
than one of any of the following stocks: Blue whale (Eastern North 
Pacific stock), humpback whale (CA/OR/WA, Mexico DPS), and sperm whale 
(Hawaii stock). Accordingly, NMFS has evaluated under the negligible 
impact standard the M/SI of 0.14 or 0.29 whales annually from each of 
these species or stocks (i.e., 1 or 2 takes, respectively, divided by 
seven years to get the annual number), along with the expected 
incidental takes by harassment.

Explosives

    The Navy's model and quantitative analysis process used for the 
2018 HSTT FEIS/OEIS and in the Navy's 2017 and 2019 applications to 
estimate potential exposures of marine mammals to

[[Page 41862]]

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). Specifically, over the course of a 
modelled maximum year of training and testing, the Navy's model and 
quantitative analysis process estimates M/SI of two short-beaked common 
dolphins and one California sea lion as a result of exposure to 
explosive training and testing activities (please see Section 6 of the 
2017 Navy application where it is explained how maximum annual 
estimates are calculated). Over the five[hyphen]year period of the 2018 
HSTT regulations, mortality of 6 short-beaked common dolphins and 4 
California sea lions was estimated and authorized (10 marine mammals in 
total) as a result of exposure to explosive training and testing 
activities. In extending the same training and testing activities for 
an additional two years, over the seven[hyphen]year period of the 
regulations M/SI of 8 short-beaked common dolphins and 5 California sea 
lions (13 marine mammals in total) is estimated as a result of exposure 
to explosive training and testing activities, and is therefore 
authorized. As explained in the aforementioned Analytical Approach 
technical report, expected impacts were calculated considering spatial 
and seasonal differences in model inputs, as well as the expected 
variation in the number of training and testing events from year to 
year, described as representative and maximum levels of activity. The 
summed impacts over any multi-year period, therefore, are the expected 
value for impacts over that time period rather than a multiple of a 
single maximum year's impacts. Therefore, calculating the seven-year 
total is not a matter of simply multiplying the annual estimate by 
seven, as the total amount of estimated mortalities over the seven 
years covered by the 2019 Navy application is less than the sum total 
of each year. As explained earlier, although the annual estimates are 
based on the maximum number of activities per year and therefore the 
maximum estimated takes, the seven-year total take estimates are based 
on the sum of three maximum years and four representative years. NMFS 
coordinated with the Navy in the development of their take estimates 
and concurs with the Navy's approach for estimating the number of 
animals from each species or stock that could be taken by M/SI from 
explosives.

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 
stock(s) and its habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of the species or stock(s) for subsistence uses (``least 
practicable 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. For the full 
discussion of how NMFS interprets least practicable adverse impact, 
including how it relates to the negligible-impact standard, see the 
Mitigation Measures section in the 2018 HSTT final rule.
    Section 101(a)(5)(A)(i)(II) requires NMFS to issue, in conjunction 
with its authorization, binding--and 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 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.
---------------------------------------------------------------------------

    \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).
---------------------------------------------------------------------------

Implementation of Least Practicable Adverse Impact Standard

    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, under section 101(a)(5)(A)(ii) 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

[[Page 41863]]

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 lower value (e.g., decreased disturbance in an area of high 
productivity but of less firmly established biological importance). 
Regarding practicability, a measure might involve restrictions in an 
area or time that impede the Navy's ability to certify a strike group 
(higher impact on mission effectiveness), 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. 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 will be 
carefully considered to determine the types of mitigation that are 
appropriate under the least practicable adverse impact standard. For 
more detail on how we apply these factors, see the discussion in the 
Mitigation Measures section of the 2018 HSTT final rule.
    NMFS fully reviewed the Navy's specified activities and the 
mitigation measures for the 2018 HSTT rulemaking and determined that 
the mitigation measures would result in the least practicable adverse 
impact on marine mammals. There is no change in either the activities 
or the mitigation measures for this rule. See the 2019 Navy application 
and the 2018 HSTT final rule for detailed information on the Navy's 
mitigation measures. 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 
Chapter 5 (Mitigation) of the 2018 HSTT FEIS/OEIS. The process 
described in Chapter 5 (Mitigation) of the 2018 HSTT FEIS/OEIS robustly 
supported NMFS' independent evaluation of whether the mitigation 
measures would meet the least practicable adverse impact standard. The 
Navy has implemented the mitigation measures under the 2018 HSTT 
regulations and will be required to continue implementation of the 
mitigation measures identified in this rule for the full seven years it 
covers to avoid or reduce potential impacts from acoustic, explosive, 
and physical disturbance and ship strike stressors.
    In its 2019 application, the Navy proposed no changes to the 
mitigation measures in the 2018 HSTT final rule and there is no new 
information that affects NMFS' assessment of the applicability or 
effectiveness of those measures over the new seven-year period. See the 
2018 HSTT proposed rule and the 2018 HSTT final rule for our full 
assessment of these measures. In summary, 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 or explosives, ship strike, and impacts to marine mammal 
habitat. Specifically, the Navy will use a combination of delayed 
starts, powerdowns, and shutdowns to minimize or avoid M/SI, 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 (several of which were added in the 2018 HSTT final rule 
since the previous HSTT MMPA incidental take rule) that will reduce 
take of marine mammals in areas or at times where they are known to 
engage in important behaviors, such as feeding or 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. Summaries of the Navy's 
procedural mitigation measures and mitigation areas for the HSTT Study 
Area are provided in Tables 14 and 15.

               Table 14--Summary of Procedural Mitigation
------------------------------------------------------------------------
                                     Mitigation zone sizes and other
     Stressor or activity                     requirements
------------------------------------------------------------------------
Environmental Awareness and      Afloat Environmental Compliance
 Education.                      Training program for applicable
                                 personnel.
Active Sonar..................  Depending on sonar source:
                                    1,000 yd power down, 500 yd
                                    power down, and 200 yd shut down.
                                    200 yd shut down.
Air Guns......................   150 yd.
Pile Driving..................   100 yd.
Weapons Firing Noise..........   30 degrees on either side of
                                 the firing line out to 70 yd.
Explosive Sonobuoys...........   600 yd.
Explosive Torpedoes...........   2,100 yd.
Explosive Medium-Caliber and     1,000 yd (large-caliber
 Large-Caliber Projectiles.      projectiles).
                                 600 yd (medium-caliber
                                 projectiles during surface-to-surface
                                 activities).
                                 200 yd (medium-caliber
                                 projectiles during air-to-surface
                                 activities).
Explosive Missiles and Rockets   2,000 yd (21-500 lb net
                                 explosive weight).

[[Page 41864]]

 
                                 900 yd (0.6-20 lb net explosive
                                 weight).
Explosive Bombs...............   2,500 yd.
Sinking Exercises.............   2.5 nmi.
Explosive Mine Countermeasure    2,100 yd (6-650 lb net
 and Neutralization Activities.  explosive weight).
                                 600 yd (0.1-5 lb net explosive
                                 weight).
Explosive Mine Neutralization    1,000 yd (21-60 lb net
 Activities Involving Navy       explosive weight for positive control
 Divers.                         charges and charges using time-delay
                                 fuses).
                                 500 yd (0.1-20 lb net explosive
                                 weight for positive control charges).
Underwater Demolition Multiple   700 yd.
 Charge--Mat Weave and
 Obstacle Loading.
Maritime Security Operations--   200 yd.
 Anti-Swimmer Grenades.
Vessel Movement...............   500 yd (whales).
                                 200 yd (other marine mammals).
Towed In-Water Devices........   250 yd (marine mammals).
Small-, Medium-, and Large-      200 yd.
 Caliber Non-Explosive
 Practice Munitions.
Non-Explosive Missiles and       900 yd.
 Rockets.
Non-Explosive Bombs and Mine     1,000 yd.
 Shapes.
------------------------------------------------------------------------
Notes: lb: pounds; nmi: nautical miles; yd: yards.


        Table 15--Summary of Mitigation Areas for Marine Mammals
------------------------------------------------------------------------
               Summary of mitigation area requirements \1\
-------------------------------------------------------------------------
Hawaii Island Mitigation Area (year-round)
     Navy personnel must not conduct more than 300 hours of MF1
     surface ship hull-mounted mid-frequency active sonar or 20 hours of
     MF4 dipping sonar, or use explosives that could potentially result
     in takes of marine mammals during training and testing.\1\
4-Islands Region Mitigation Area (November 15-April 15 for active sonar;
 year-round for explosives)
     Navy personnel must not use MF1 surface ship hull-mounted
     mid-frequency active sonar or explosives that could potentially
     result in takes of marine mammals during training and testing.\2\
Humpback Whale Special Reporting Areas (December 15-April 15)
     Navy personnel must report the total hours of surface ship
     hull-mounted mid-frequency active sonar used in the special
     reporting areas in its annual training and testing activity reports
     submitted to NMFS.
San Diego Arc, San Nicolas Island, and Santa Monica/Long Beach
 Mitigation Areas (June 1--October 31)
     Navy personnel must not conduct more than a total of 200
     hours of MF1 surface ship hull-mounted mid-frequency active sonar
     in the combined areas, excluding normal maintenance and systems
     checks, during training and testing.\1\
     Within the San Diego Arc Mitigation Area, Navy personnel
     must not use explosives that could potentially result in the take
     of marine mammals during large-caliber gunnery, torpedo, bombing,
     and missile (including 2.75 inch rockets) activities during
     training and testing.\1\
     Within the San Nicolas Island Mitigation Area, Navy
     personnel must not use explosives that could potentially result in
     the take of marine mammals during mine warfare, large-caliber
     gunnery, torpedo, bombing, and missile (including 2.75 inch
     rockets) activities during training.\1\
     Within the Santa Monica/Long Beach Mitigation Area, Navy
     personnel must not use explosives that could potentially result in
     the take of marine mammals during mine warfare, large-caliber
     gunnery, torpedo, bombing, and missile (including 2.75 inch
     rockets) activities during training and testing.\1\
Santa Barbara Island Mitigation Area (year-round)
     Navy personnel must not use MF1 surface ship hull-mounted
     mid-frequency active sonar during training and testing, or
     explosives that could potentially result in the take of marine
     mammals during medium-caliber or large-caliber gunnery, torpedo,
     bombing, and missile (including 2.75 inch rockets) activities
     during training.\1\
Awareness Notification Message Areas (seasonal according to species)
     Navy personnel must issue awareness notification messages
     to alert ships and aircraft to the possible presence of humpback
     whales (November-April), blue whales (June-October), gray whales
     (November-March), or fin whales (November-May).
------------------------------------------------------------------------
\1\ In the 2018 HSTT Final Rule we inadvertently included ``Mitigation
  Areas for Shallow-water Coral Reefs and Precious Coral Beds (year-
  round)'' in this table. As this mitigation area does not relate to
  marine mammals we have not included it here.
\2\ If Naval units need to conduct more than the specified amount of
  training or testing, they will obtain permission from the appropriate
  designated Command authority prior to commencement of the activity.
  The Navy will provide NMFS with advance notification and include the
  information in its annual activity reports submitted to NMFS.

Mitigation Conclusions

    NMFS has carefully evaluated the Navy's proposed mitigation 
measures--many of which were developed with NMFS' input during the 
previous phases of Navy training and testing authorizations and none of 
which have changed since our evaluation during the 2018 HSTT 
rulemaking--and considered a broad range of other measures (i.e., the 
measures considered but eliminated in the 2018 HSTT FEIS/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 stocks 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 stocks and their habitat; the proven or likely 
efficacy of the measures; and the practicability of the measures for 
applicant implementation,

[[Page 41865]]

including consideration of personnel safety, practicality of 
implementation, and impact on the effectiveness of the military 
readiness activity. There is no new information that affects our 
analysis from the 2018 HSTT rulemaking, all of which remains applicable 
and valid for our assessment of the appropriateness of the mitigation 
measures during the seven-year period of this rule.
    Based on our evaluation of the Navy's measures (which are being 
implemented under the 2018 HSTT regulations), as well as other measures 
considered by the Navy and NMFS, NMFS has determined that the Navy's 
mitigation measures are appropriate means of effecting the least 
practicable adverse impact on marine mammal species or stocks 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, as described in more 
detail below, the 2018 HSTT final rule includes an adaptive management 
provision, which NMFS has extended for the additional two years of this 
rule, which 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 the 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.
    In its 2019 application, the Navy proposed no changes to the 
monitoring described in the 2018 HSTT final rule. They would continue 
implementation of the robust Integrated Comprehensive Monitoring 
Program and Strategic Planning Process described in the 2018 HSTT final 
rule. The Navy's monitoring strategy, currently required by the 2018 
HSTT regulations and extended for two years under this final rule, is 
well-designed to work across Navy ranges to help better understand the 
impacts of the Navy's activities on marine mammals and their habitat by 
focusing on learning more about marine mammal occurrence in different 
areas and exposure to Navy stressors, marine mammal responses to 
different sound sources, and the consequences of those exposures and 
responses on marine mammal populations. Similarly, the seven-year 
regulations include identical adaptive management provisions and 
reporting requirements as the 2018 HSTT regulations. There is no new 
information to indicate that the monitoring measures put in place under 
the 2018 HSTT final rule do not remain applicable and appropriate for 
the seven-year period of this rule. See the Monitoring section of the 
2018 HSTT final rule for more details on the monitoring that would be 
required under this rule. In addition, please see the 2019 Navy 
application, which references Chapter 13 of the 2017 Navy application 
for full details on the monitoring and reporting that will be conducted 
by the Navy.

Adaptive Management

    The 2018 HSTT regulations governing the take of marine mammals 
incidental to Navy training and testing activities in the HSTT 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 2019 Navy 
application proposed no changes to the adaptive management component 
included in the 2018 HSTT final rule.
    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 would 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) compiled results of Navy funded R&D studies; (3) 
results from specific stranding investigations; (4) results from 
general marine mammal and sound research; and (5) any information which 
reveals that marine mammals may have been taken in a manner, extent, or 
number not authorized by these regulations or subsequent LOAs. The 
results from monitoring reports and other studies may be viewed at 
https://www.navymarinespeciesmonitoring.us.

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 will be 
posted to the Navy's Marine Species Monitoring web portal: http://www.navymarinespeciesmonitoring.us. The 2019 Navy application proposed 
no changes to the reporting requirements. Except as discussed below, 
reporting requirements would remain identical to those described in the 
2018 HSTT final rule, and there is no new information to indicate that 
the reporting requirements put in place under the 2018 HSTT final rule 
do not remain applicable and appropriate for the seven-year period of 
this final rule. See the Reporting section of the 2018 HSTT final rule 
for more details on the reporting that is required under this rule.
    In addition, the 2018 HSTT proposed and final rules unintentionally 
failed to include the requirement for the Navy to submit a final 
activity ``close out'' report at the end of the regulatory period. That 
oversight is being corrected through this rulemaking. This 
comprehensive training and testing activity report will provide the 
annual totals for each sound source bin with a comparison to the annual 
allowance and the seven-year

[[Page 41866]]

total for each sound source bin with a comparison to the seven-year 
allowance. Additionally, if there are any changes to the sound source 
allowance, this 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 2018 HSTT FEIS/OEIS and MMPA final rule.

Analysis and Negligible Impact Determination

    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 addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through mortality, serious injury, and Level A or Level B 
harassment (as presented in Tables 11 and 12), 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 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 
environmental baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, other ongoing 
sources of human-caused mortality, and ambient noise levels).
    In the Estimated Take of Marine Mammals sections of this final rule 
and the 2018 HSTT final rule (where the activities, species and stocks, 
potential effects, and mitigation measures are the same as for this 
rule), we identified the subset of potential effects that would be 
expected to rise to the level of takes both annually and over the 
seven-year period covered by this rule, and then identified the number 
of each of those mortality takes that we believe could occur or 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 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 final rule we 
evaluated the likely impacts of the enumerated maximum number of 
harassment takes that were proposed for authorization and reasonably 
expected to occur, in the context of the specific circumstances 
surrounding these predicted takes. We also assessed M/SI takes that 
have the potential to occur, as well as considering the traits and 
statuses of the affected species and stocks. Lastly, 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 
stock. Because all of the Navy's specified activities would occur 
within the ranges of the marine mammal stocks identified in the rule, 
all negligible impact analyses and determinations are at the stock 
level (i.e., additional species-level determinations are not needed).
    The Navy proposed no changes to the nature or level of the 
specified activities or the boundaries of the HSTT Study Area, and 
therefore the training and testing activities (e.g., equipment and 
sources used, exercises conducted) are the same as those analyzed in 
the 2018 HSTT final rule. In addition, the mitigation, monitoring, and 
nearly all reporting measures are identical to those described and 
analyzed in the 2018 HSTT final rule. As described above, there is no 
new information since the publication of the 2018 HSTT final rule 
regarding the impacts of the specified activities on marine mammals, 
the status and distribution of any of the affected marine mammal 
species or stocks, or the effectiveness of the mitigation and 
monitoring measures that would change our analyses, except for one 
species. For that one species--gray whales--we have considered the 
effects of the new UME on the west coast of North America along with 
the effects of the Navy's activities in the negligible impact analysis.

Harassment

    As described in the Estimated Takes of Marine Mammals section, the 
annual number of takes authorized and reasonably expected to occur by 
Level A harassment and Level B harassment (based on the maximum number 
of activities per 12-month period) are identical to those presented in 
Tables 41 through 42 in the Take Requests section of the 2018 HSTT 
final rule. As such, the negligible impact analyses and determinations 
of the effects of the estimated Level A harassment and Level B 
harassment takes on annual rates of recruitment or survival for each 
species and stock are nearly identical to and substantively unchanged 
from those presented in the 2018 HSTT final rule. The primary 
difference is that the annual levels of take and the associated effects 
on reproduction or survival would occur for the seven-year period of 
this rule instead of the five-year period of the 2018 HSTT final rule, 
which will make no difference in effects on annual rates of recruitment 
or survival. The other differences in the analyses include our 
consideration of the newly-declared gray whale UME and slightly 
modified explosive take estimates, neither of which, as described 
below, affect the results of the analyses or our determinations. For 
detailed discussion of the impacts that affected individuals may 
experience given the specific characteristics of the specified 
activities and required mitigation (e.g., from behavioral disruption, 
masking, and temporary or permanent threshold shift), along with the 
effects of the expected Level A harassment and Level B harassment take 
on reproduction and survival, see the applicable subsections in the 
Analysis and Negligible Impact Determination section of the 2018 HSTT 
final rule (83 FR 66977-67018; December 27, 2018).

Serious Injury or Mortality

    Based on the information and methods discussed in the Estimated 
Take of Marine Mammals section (which are identical to those used in 
the 2018 HSTT final rule), the number of potential mortalities due to 
ship strike requested and authorized over the seven-year period of this 
rule is the same as those authorized in the 2018 HSTT final rule. As 
the potential mortalities are now spread over seven years rather than 
five, an annual average of 0.29 gray whales (Eastern North Pacific 
stock), fin whales (CA/OR/WA stock), and humpback whales (Central North 
Pacific stock) and an annual average of 0.14 blue whales (Eastern North 
Pacific stock), humpback whales (CA/OR/WA stock, Mexico DPS), and sperm 
whales (Hawaii stock) as described in Table 16 (i.e., one, or two, 
take(s) over seven years divided by seven to get the annual number) are 
expected to potentially occur and are authorized. As this annual number 
is less than that analyzed and authorized in the 2018 HSTT final rule, 
which was

[[Page 41867]]

an annual average of 0.4 whales or 0.2 whales respectively for the same 
species and stocks, and with the exception of the new gray whale UME on 
the U.S. West Coast and updated abundance information for the Eastern 
North Pacific stock of blue whales (available in the 2019 draft SARs), 
no other relevant information about the status, abundance, or effects 
of M/SI on each species or stock has changed, the analysis of the 
effects of vessel strike mirrors that presented in the 2018 HSTT final 
rule.

                                                    Table 16--Summary Information Related to Mortalities Requested for Ship Strike, 2018-2025
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Annual
                                                  authorized                          Fisheries        Vessel collisions      Potential     Residual PBR
                                     Stock          take by      Total annual   interactions  (Y/N);  (Y/N);  annual rate    biological      (PBR minus      Stock trend *    Recent UME  (Y/N);
        Species (stock)            abundance    serious injury    M/SI * \2\      annual rate  of M/      of M/SI from     removal  (PBR)   annual M/SI)          \5\          number and year
                                   (Nbest) *     or mortality                    SI from  fisheries    vessel collision *       * \3\            \4\                             (since 2007)
                                                      \1\                          interactions *
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Fin whale (CA/OR/WA stock)....           9,029            0.29          >=43.5  Y; >=0.5............  Y, 43..............              81            37.5  [uarr]..........  N.
Gray whale (Eastern North               26,960            0.29             139  Y, 9.6..............  Y, 0.8.............             801             662  stable since      Y, 264, 2019.
 Pacific stock).                                                                                                                                            2003.
Humpback whale (CA/OR/WA                 2,900            0.14          >=42.1  Y; >=17.3...........  Y, 22..............            33.4            -8.7  [uarr]            N.
 stock, Mexico DPS).                                                                                                                                        (historically);
                                                                                                                                                            stable.
Humpback whale (Central North           10,103            0.29              25  Y; 18...............  Y, 1.4.............              83              58  [uarr]..........  N.
 Pacific stock) \6\.
Sperm whale (Hawaii stock)....       \7\ 4,559            0.14             0.7  Y, 0.7..............  N..................              14            13.3  ?...............  N.
Blue whale (Eastern North                1,496            0.14          >=19.4  >=1.44..............  Y, 18..............             2.1           -17.3  stable..........  Y; 3, 2007.
 Pacific Stock).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Presented in the 2018 final SARs and draft 2019 SARs.
\1\ This column represents the annual take by serious injury or mortality (M/SI) by vessel collision and was calculated by the number of mortalities for authorization divided by seven years
  (the length of the rule and LOAs).
\2\ This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock. This number comes from the SAR, but deducts the takes accrued
  from either other Navy strikes or NMFS' Southwest Fisheries Science Center (SWFSC) takes in the SARs to ensure not double-counted against PBR. However, for these species, there were no takes
  from either other Navy activities or SWFSC in the SARs to deduct that would be considered double-counting.
\3\ Potential biological removal (PBR) is defined in section 3 of the MMPA. See the Analysis and Negligible Impact Determination section of the 2018 HSTT final rule for a description of PBR.
\4\ This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/SI, which is presented in the SARs). This
  value represents the residual PBR for the stock in the stock's entire range.
\5\ See relevant SARs for more information regarding stock status and trends.
\6\ Some values for the Central North Pacific stock of humpback whales were unintentionally presented incorrectly in Table 69 of the 2018 HSTT final rule. The correct values are provided here.
  These transcription errors do not affect the analysis or conclusions in the 2018 HSTT final rule, as the correct values were used in the analysis presented in the Analysis and Negligible
  Impact Determination section.
\7\ The stock abundance for the Hawaii stock of sperm whales was unintentionally presented incorrectly as 5,559 in the 2018 HSTT final rule and has been corrected here. This transcription
  error does not affect the analysis or conclusions reached in the 2018 HSTT final rule.

    The Navy has also requested a small number of takes by M/SI from 
explosives. To calculate the annual average of mortalities for 
explosives in Table 17 we used the same method as described for vessel 
strikes. The annual average is the total number of takes over seven 
years divided by seven. Specifically, NMFS is authorizing the following 
M/SI takes from explosives: 5 California sea lions and 8 short-beaked 
common dolphins over the seven-year period (therefore 0.71 mortalities 
annually for California sea lions and 1.14 mortalities annually for 
short-beaked common dolphins), as described in Table 17. As this annual 
number is less than that analyzed and authorized in the 2018 HSTT final 
rule, which was an annual average of 0.8 California sea lions and 1.2 
short-beaked common dolphins, and no other relevant information about 
the status, abundance, or effects of mortality on each species or stock 
has changed, the analysis of the effects of explosives mirrors that 
presented in the 2018 HSTT final rule.

                                                         Table 17--Summary Information Related to Mortalities From Explosives, 2018-2025
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Annual
                                                  authorized                          Fisheries                                 SWFSC      Residual  PBR-
                                     Stock          take by      Total annual   interactions  (Y/N);                         authorized       PBR minus      Stock trend *    UME (Y/N);  number
        Species (stock)            abundance    serious injury    M/SI * \2\      annual rate  of M/         PBR *         take  (annual)    annual M/SI          \5\              and year
                                   (Nbest) *      or mortality                   SI from  fisheries                              \3\        and SWFSC \4\
                                                      \1\                          interactions *
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion (U.S.              257,606            0.71           319.4  Y;197...............  14,011.............             6.6          13,685  [uarr]..........  Y; 8,112; 2013.
 stock).
Short-beaked common dolphin            969,861            1.14            >=40  Y; >=40.............  8,393..............             2.8         8,350.2  ?...............  N.
 (CA/OR/WA stock).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Presented in the 2018 final SARs. No changes for these stocks were included in the 2019 draft SARs.
\1\ This column represents the annual take by serious injury or mortality (M/SI) during explosive detonations and was calculated by the number of mortalities planned for authorization divided
  by seven years (the length of the rule and LOAs).
\2\ This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock. This number comes from the SAR, but deducts the takes accrued
  from either other Navy activities or NMFS' SWFSC takes in the SARs to ensure they are not double-counted against PBR. In this case, for California sea lion 0.8 annual M/SI from the U.S. West
  Coast during scientific trawl and longline operations conducted by NMFS and 1.8 annual M/SI from marine mammal research related mortalities authorized by NMFS was deducted from total annual
  M/SI (322).
\3\ This column represents annual take authorized through NMFS' SWFSC rulemaking/LOAs (80 FR 58982).
\4\ This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/SI column and the annual authorized take
  from the SWFSC column). In the case of California sea lion the M/SI column (319.4) and the annual authorized take from the SWFSC (6.6) were subtracted from the calculated PBR of 14,011. In
  the case of Short-beaked common dolphin the M/SI column (40) and the annual authorized take from the SWFSC (2.8) were subtracted from the calculated PBR of 8,393.
\5\ See relevant SARs for more information regarding stock status and trends.

    See the Serious Injury or Mortality subsection in the Analysis and 
Negligible Impact Determination section of the 2018 HSTT final rule (83 
FR 66985-66993; December 27, 2018) for detailed discussions of the 
impacts of M/SI, including a description of how the agency uses the PBR 
metric and other factors to inform our analysis, and an analysis of the 
impacts on each species and stock for which M/SI was proposed for 
authorization, including

[[Page 41868]]

the relationship of potential mortality for each species to the 
insignificance threshold and residual PBR.
Stocks With M/SI Below the Insignificance Threshold
    As noted in the Serious Injury or Mortality subsection of the 
Negligible Impact Analysis and Determination section in the 2018 HSTT 
final rule, for a species or stock with incidental M/SI less than 10 
percent of residual PBR, we consider M/SI from the specified activities 
to represent an insignificant incremental increase in ongoing 
anthropogenic M/SI that alone (i.e., in the absence of any other take 
and barring any other unusual circumstances) will clearly not adversely 
affect annual rates of recruitment and survival. In this case, as shown 
in Tables 16 and 17, the following species or stocks have potential or 
estimated M/SI from ship strike and explosive takes, respectively, 
authorized below their insignificance threshold: fin whale (CA/OR/WA 
stock), gray whale (Eastern North Pacific stock), humpback whale 
(Central North Pacific stock), sperm whale (Hawaii stock), California 
sea lion (U.S stock), and short-beaked common dolphin (CA/OR/WA stock). 
While the authorized M/SI of California sea lions (U.S. stock) and gray 
whales (Eastern North Pacific stock) are below the insignificance 
threshold, because of the recent UMEs, we further address how the 
authorized M/SI and the UME inform the negligible impact determination 
immediately below. For the other four stocks with authorized M/SI below 
the insignificance threshold, there are no other known factors, 
information, or unusual circumstances that indicate anticipated M/SI 
below the insignificance threshold could have adverse effects on annual 
rates of recruitment or survival and they are not discussed further. 
For the remaining two stocks with anticipated potential M/SI above the 
insignificance threshold, how that M/SI compares to residual PBR, as 
well as additional factors, as appropriate, are discussed below as 
well.

California Sea Lion (U.S. Stock)

    The estimated (and authorized) lethal take of California sea lions 
is well below the insignificance threshold (0.71 as compared to a 
residual PBR of 13,686) and NMFS classifies the stock as ``increasing'' 
in the 2018 final SAR, the most recent SAR available for this stock. 
Nonetheless, we consider here how the 2013-2016 (UME closed on May 6, 
2020) California Sea Lion UME informs our negligible impact 
determination. This UME was confined to pup and yearling sea lions and 
many were emaciated, dehydrated, and underweight. NMFS staff confirmed 
that the mortality of pups and yearlings returned to normal in 2017 and 
2018. The UME Working Group recommended closure of UME in April, 2020 
and the UME was closed on May 6, 2020. NMFS' findings indicate that a 
change in the availability of sea lion prey, especially anchovy and 
sardines, a high value food source for nursing mothers, was a likely 
contributor to the large number of strandings. Sardine spawning grounds 
shifted further offshore in 2012 and 2013, and while other prey were 
available (market squid and rockfish), these may not have provided 
adequate nutrition in the milk of sea lion mothers supporting pups, or 
for newly-weaned pups foraging on their own. Although the pups showed 
signs of some viruses and infections, findings indicate that this event 
was not caused by disease, but rather by the lack of high quality, 
close-by food sources for nursing mothers. Average mortalities from 
2013-2017 were 1,000-3,000 more annually than they were in the previous 
10 years. However, even if these unusual mortalities were still 
occurring (with current data suggesting they are not), combined with 
other annual human-caused mortalities, and viewed through the PBR lens 
(for human-caused mortalities), total human-caused mortality (inclusive 
of the potential for additional UME deaths) would still fall well below 
residual PBR. Further, the loss of pups and yearlings is not expected 
to have as much of an effect on annual population rates as the death of 
adult females. In conclusion, because of the abundance, population 
trend, and residual PBR of this stock, as well as the fact that the 
increased mortality stopped two years ago, this UME is not expected to 
have any impacts on individuals during the period of this final rule, 
nor is it thought to have had impacts on the population rate when it 
was occurring that would influence our evaluation of the effects of the 
mortality authorized on the stock.

Gray Whales (Eastern North Pacific Stock)

    Since January 2019, gray whale strandings along the west coast of 
North America have been significantly higher than the previous 18-year 
averages. Preliminary findings from necropsies have shown evidence of 
emaciation. The seasonal pattern of elevated strandings in the spring 
and summer months is similar to that of the previous gray whale UME in 
1999-2000. Current total monthly strandings are slightly higher than 
1999 and lower than 2000. If strandings continue to follow a similar 
pattern, we would anticipate a decrease in strandings in late summer 
and fall. However, combined with other annual human-caused mortalities, 
and viewed through the PBR lens (for human-caused mortalities), total 
human-caused mortality (inclusive of the potential for additional UME 
deaths) would still fall well below residual PBR and the insignificance 
threshold. Because of the abundance, population trend (increasing, 
despite the UME in 1999-2000), and residual PBR (662) of this stock, 
this UME is not expected to have impacts on the population rate that, 
in combination with the effects of mortality authorized, would affect 
annual rates of recruitment or survival.
Stocks with M/SI above the Insignificance Threshold

Humpback Whale (CA/OR/WA Stock, Mexico DPS)

    For this stock, PBR is currently set at 16.7 for U.S. waters and 
33.4 for the stock's entire range. In the 2018 HSTT final rule and 2019 
HSTT proposed rule we inadvertently considered only the PBR for U.S. 
waters (as presented in the SAR summary tables). As the HSTT Study Area 
extends beyond U.S. waters and activities have the potential to impact 
the entire stock, we have corrected this here and present the analysis 
using the PBR for the stock's entire range. The total annual M/SI is 
estimated at greater than or equal to 42.1, yielding a residual PBR of 
-8.7. With the corrected PBR, this potential impact on the stock is 
less than what was presented in both the 2018 HSTT final rule and 2019 
HSTT proposed rule. NMFS authorizes one M/SI over the seven-year 
duration of the rule (which is 0.14 annually for the purposes of 
comparing to PBR and considering other effects on annual rates of 
recruitment and survival), which means that residual PBR is exceeded by 
8.84. In the 2018 HSTT final rule the PBR was correctly reported as 
33.4 (PBR for the stock's entire range), however the total annual M/SI 
was incorrectly reported as greater than or equal to 40.76 (yielding a 
residual PBR of -7.36). These transcription errors do not affect the 
fundamental analysis or conclusion reached in the 2018 HSTT final rule, 
however, and we have corrected these values here using data from the 
2019 draft SARs.
    In the commercial fisheries setting for ESA-listed marine mammals 
(which is similar to the non-fisheries incidental take setting, in that 
a negligible impact determination is required that is based

[[Page 41869]]

on the assessment of take caused by the activity being analyzed) NMFS 
may find the impact of the authorized take from a specified activity to 
be negligible even if total human-caused mortality exceeds PBR, if the 
authorized mortality is less than 10 percent of PBR and management 
measures are being taken to address serious injuries and mortalities 
from the other activities causing mortality (i.e., other than the 
specified activities covered by the incidental take authorization under 
consideration). When those considerations are applied in the section 
101(a)(5)(A) context here, the authorized lethal take (0.14 annually) 
of humpback whales from the CA/OR/WA stock is significantly less than 
10 percent of PBR (in fact less than 1 percent of 33.4) and there are 
management measures in place to address M/SI from activities other than 
those the Navy is conducting (as discussed below).
    Based on identical simulations as those conducted to identify 
Recovery Factors for PBR in Wade et al. (1998), but where values less 
than 0.1 were investigated (P. Wade, pers. comm.), we predict that 
where the mortality from a specified activity does not exceed Nmin * 
\1/2\ Rmax * 0.013, the contemplated mortality for the specific 
activity will not delay the time to recovery by more than 1 percent. 
For this stock of humpback whales, Nmin * \1/2\ Rmax * 0.013 = 1.45 and 
the annual mortality proposed for authorization is 0.14 (i.e., less 
than 1.45), which means that the mortality authorized in this rule for 
HSTT activities would not delay the time to recovery by more than 1 
percent.
    As described in the 2018 HSTT final rule, NMFS must also ensure 
that impacts by the applicant on the species or stock from other types 
of take (i.e., harassment) do not combine with the impacts from M/SI to 
adversely affect the species or stock via impacts on annual rates of 
recruitment or survival, which is discussed further below in the 
species- and stock-specific section.
    In November 2019, NMFS published 2019 draft SARs in which PBR is 
reported as 33.4 with the predicted average annual mortality greater 
than or equal to 42.1 (including 22 estimated from vessel collisions 
and greater than 17.3 observed fisheries interactions). While the 
observed M/SI from vessel strikes remains low at 2.2 per year, the 2018 
final and 2019 draft SARs rely on a new method to estimate annual 
deaths by ship strike utilizing an encounter theory model that combined 
species distribution models of whale density, vessel traffic 
characteristics, and whale movement patterns obtained from satellite-
tagged animals in the region to estimate encounters that would result 
in mortality (Rockwood et al., 2017). The model predicts 22 annual 
mortalities of humpback whales from this stock from vessel strikes. The 
authors (Rockwood et al., 2017) do not suggest that ship strike 
suddenly increased to 22. In fact, the model is not specific to a year, 
but rather offers a generalized prediction of ship strike off the U.S. 
West Coast. Therefore, if the Rockwood et al. (2017) model is an 
accurate representation of vessel strike, then similar levels of ship 
strike have been occurring in past years as well. Put another way, if 
the model is correct, for some number of years total human-caused 
mortality has been significantly underestimated, and PBR has been 
similarly exceeded by a notable amount, and yet the CA/OR/WA stock of 
humpback whales is considered stable nevertheless.
    The CA/OR/WA stock of humpback whales experienced a steady increase 
from the 1990s through approximately 2008, and more recent estimates 
through 2014 indicate a leveling off of the population size. This stock 
is comprised of the feeding groups of three DPSs. Two DPSs associated 
with this stock are listed under the ESA as either endangered (Central 
America DPS) or threatened (Mexico DPS), while the third is not listed. 
The mortality authorized by this rule is for an individual from the 
Mexico DPS only. As described in the Final Rule Identifying 14 DPSs of 
the Humpback Whale and Revision of Species-Wide Listing (81 FR 62260, 
September 8, 2016), the Mexico DPS was initially proposed not to be 
listed as threatened or endangered, but the final decision was changed 
in consideration of a new abundance estimate using a new methodology 
that was more accurate (less bias from capture heterogeneity and lower 
coefficient of variation) and resulted in a lower abundance than was 
previously estimated. To be clear, the new abundance estimate did not 
indicate that the numbers had decreased, but rather, the more accurate 
new abundance estimate (3,264), derived from the same data but based on 
an integrated spatial multi-strata mark recapture model (Wade et al., 
2016) was simply notably lower than earlier estimates, which were 
6,000-7,000 from the SPLASH project (Calambokidis et al., 2008) or 
higher (Barlow et al., 2011). The updated abundance was still higher 
than 2,000, which is the Biological Review Team's (BRT) threshold 
between ``not likely to be at risk of extinction due to low abundance 
alone'' and ``increasing risk from factors associated with low 
abundance.'' Further, the BRT concluded that the DPS was unlikely to be 
declining because of the population growth throughout most of its 
feeding areas, in California/Oregon and the Gulf of Alaska, but they 
did not have evidence that the Mexico DPS was actually increasing in 
overall population size.
    As discussed earlier, we also take into consideration management 
measures in place to address M/SI caused by other activities. The 
California swordfish and thresher shark drift gillnet fishery is one of 
the primary causes of M/SI take from fisheries interactions for 
humpback whales on the West Coast. NMFS established the Pacific 
Offshore Cetacean Take Reduction Team in 1996 and prepared an 
associated Plan (PCTRP) to reduce the risk of M/SI via fisheries 
interactions. In 1997, NMFS published final regulations formalizing the 
requirements of the PCTRP, including the use of pingers following 
several specific provisions and the employment of Skipper education 
workshops.
    Commercial fisheries such as crab pot, gillnet, and prawn fisheries 
are also a significant source of mortality and serious injury for 
humpback whales and other large whales and, unfortunately, have 
increased mortalities and serious injuries over recent years (Carretta 
et al., 2019). However, the 2019 draft SAR notes that a recent increase 
in disentanglement efforts has resulted in an increase in the fraction 
of cases that are reported as non-serious injuries as a result of 
successful disentanglement. More importantly, since 2015, NMFS has 
engaged in a multi-stakeholder process in California (including 
California State resource managers, fishermen, non-governmental 
organizations (NGOs), and scientists) to identify and develop solutions 
and make recommendations to regulators and the fishing industry for 
reducing whale entanglements (see http://www.opc.ca.gov/whale-entanglement-working-group/), referred to as the Whale Entanglement 
Working Group. The Whale Entanglement Working Group has made 
significant progress since 2015 and is tackling the problem from 
multiple angles, including:
     Development of Fact Sheets and Best Practices for specific 
Fisheries issues (e.g., California Dungeness Crab Fishing BMPs and the 
2018-2019 Best Fishing Practices Guide);
     2018-2019 Risk Assessment and Mitigation Program (RAMP) to 
support the state of California in working collaboratively with experts 
(fishermen, researchers, NGOs, etc.) to identify and assess elevated 
levels of entanglement risk and determine the need for

[[Page 41870]]

management options to reduce risk of entanglement; and
     Support of pilot studies to test new fisheries 
technologies to reduce take (e.g., Exploring Ropeless Fishing 
Technologies for the California Dungeness Crab Fishery).
    The Working Group meets regularly, posts reports and annual 
recommendations, and makes all of their products and guidance documents 
readily accessible for the public. The March 2019 Working Group Report 
reported on the status of the fishery closure, progress and continued 
development of the RAMP (though there is a separate RAMP report), 
discussed the role of the Working Group (development of a new Charter), 
and indicated next steps.
    Importantly, in early 2019, as a result of a litigation settlement 
agreement, the California Department of Fish and Wildlife (CDFW) closed 
the Dungeness crab fishery three months early for the year, which is 
expected to reduce the number of likely entanglements. The agreement 
also limits the fishery duration over the next couple of years and has 
different triggers to reduce or close it further. Further, pursuant to 
the settlement, CDFW is required to apply for a Section 10 Incidental 
Take Permit under the ESA to address protected species interactions 
with fishing gear and crab fishing gear (pots), and they have agreed to 
prepare a Conservation Plan by May 2020. Any request for such a permit 
must include a Conservation Plan that specifies, among other things, 
what steps the applicant will take to minimize and mitigate the 
impacts, and the funding that will be available to implement such 
steps.
    Regarding measures in place to reduce mortality from other sources, 
the Channel Islands NMS staff coordinates, collects, and monitors whale 
sightings in and around a Whale Advisory Zone and the Channel Islands 
NMS region, which is within the area of highest vessel strike mortality 
(90th percentile) for humpback whales on the U.S. West Coast (Rockwood 
et al., 2017). The seasonally established Whale Advisory Zone spans 
from Point Arguello to Dana Point, including the Traffic Separation 
Schemes in the Santa Barbara Channel and San Pedro Channel. Vessels 
transiting the area from June through November are recommended to 
exercise caution and voluntarily reduce speed to 10 kn or less for 
blue, humpback, and fin whales. Channel Island NMS observers collect 
information from aerial surveys conducted by NOAA, the U.S. Coast 
Guard, California Department of Fish and Game, and Navy chartered 
aircraft. Information on seasonal presence, movement, and general 
distribution patterns of large whales is shared with mariners, NMFS' 
Office of Protected Resources, the U.S. Coast Guard, the California 
Department of Fish and Game, the Santa Barbara Museum of Natural 
History, the Marine Exchange of Southern California, and whale 
scientists. Real time and historical whale observation data collected 
from multiple sources can be viewed on the Point Blue Whale Database.
    More recently, similar efforts to reduce entanglement risk and 
severity have also been initiated in Oregon and Washington. Both Oregon 
and Washington are developing applications for ESA Incidental Take 
Permits for their commercial crab fisheries. They advocate similar best 
practices for their fishermen as California, and they are taking 
regulatory steps related to gear marking and pot limits.
    In this case, 0.14 M/SI annually means the potential for one 
mortality in one of the seven years and zero mortalities in six of 
those seven years. Therefore, the Navy would not be contributing to the 
total human-caused mortality at all in six of the seven, or 85.7 
percent, of the years covered by this rule. That means that even if a 
humpback whale from the CA/OR/WA stock were to be struck, in six of the 
seven years there could be no effect on annual rates of recruitment or 
survival from Navy-caused M/SI. Additionally, as discussed in the 
Analysis and Negligible Impact Determination section of the 2018 HSTT 
final rule, the loss of a male would have far less, if any, of an 
effect on population rates and absent any information suggesting that 
one sex is more likely to be struck than another, we can reasonably 
assume that there is a 50 percent chance that the single strike 
authorized by this rule would be a male, thereby further decreasing the 
likelihood of impacts on the population rate. In situations like this 
where potential M/SI is fractional, consideration must be given to the 
lessened impacts anticipated due to the absence of M/SI in six of the 
years and due to the fact that a single strike could be of a male.
    Lastly, we reiterate that PBR is a conservative metric and also not 
sufficiently precise to serve as an absolute predictor of population 
effects upon which mortality caps would appropriately be based. This is 
especially important given the minor difference between zero and one 
across the seven-year period covered by this rule, which is the 
smallest distinction possible when considering mortality. Wade et al. 
(1998), authors of the paper from which the current PBR equation is 
derived, note that ``Estimating incidental mortality in one year to be 
greater than the PBR calculated from a single abundance survey does not 
prove the mortality will lead to depletion; it identifies a population 
worthy of careful future monitoring and possibly indicates that 
mortality-mitigation efforts should be initiated.''
    The information included here illustrates that this humpback whale 
stock is currently stable, the potential (and authorized) mortality is 
well below 10 percent (0.4 percent) of PBR, and management actions are 
in place to minimize both fisheries interactions and ship strike from 
other vessel activity in one of the highest-risk areas for strikes. 
More specifically, although the total human-mortality exceeds PBR, the 
authorized mortality for the Navy's specified activities would 
incrementally contribute less than 1 percent of that and, further, 
given the fact that it would occur in only one of seven years and could 
be comprised of a male (far less impactful to the population), the 
potential impacts on population rates are even less. Based on all of 
the considerations described above, including consideration of the fact 
that the authorized mortality of 0.14 would not delay the time to 
recovery by more than 1 percent, we do not expect the potential lethal 
take from Navy activities, alone, to adversely affect the CA/OR/WA 
stock of humpback whales through effects on annual rates of recruitment 
or survival. Nonetheless, the fact that total human-caused mortality 
exceeds PBR necessitates close attention to the remainder of the 
impacts (i.e., harassment) on the CA/OR/WA stock of humpback whales 
from the Navy's activities to ensure that the total authorized takes 
would have a negligible impact on the species and stock. Therefore, 
this information will be considered in combination with our assessment 
of the impacts of authorized harassment takes later in the Group and 
Species-Specific Analyses section.

Blue Whale (Eastern North Pacific Stock)

    For blue whales (Eastern North Pacific stock), PBR is currently set 
at 1.23 for U.S. waters and 2.1 for the stock's entire range. In the 
2018 HSTT final rule and 2019 HSTT proposed rule we inadvertently 
presented only the PBR for U.S. waters (as presented in the SAR summary 
tables). As the HSTT Study Area extends beyond U.S. waters and 
activities have the potential to impact the entire stock, we have 
corrected this here and present the analysis using the PBR for the 
stock's entire range. The

[[Page 41871]]

total annual M/SI is estimated at greater than or equal to 19.4, 
yielding a residual PBR of -17.3. NMFS authorizes one M/SI for the Navy 
over the seven-year duration of the rule (indicated as 0.14 annually 
for the purposes of comparing to PBR and evaluating overall effects on 
annual rates of recruitment and survival), which means that residual 
PBR is exceeded by 17.44. However, as described previously, in the 
commercial fisheries setting for ESA-listed marine mammals (which is 
similar to the incidental take setting, in that the negligible impact 
determination is based on the assessment of take caused by the activity 
being analyzed) NMFS may find the impact of the authorized take from a 
specified activity to be negligible even if total human-caused 
mortality exceeds PBR, if the authorized mortality is less than 10 
percent of PBR and management measures are being taken to address 
serious injuries and mortalities from the other activities causing 
mortality (i.e., other than the specified activities covered by the 
incidental take authorization in consideration). When those 
considerations are applied in the section 101(a)(5)(A) context, the 
authorized lethal take (0.14 annually) of blue whales from the Eastern 
North Pacific stock is less than 10 percent of PBR (which is 2.1) and 
there are management measures in place to address M/SI from activities 
other than those the Navy is conducting (as discussed below). Perhaps 
more importantly, the population is considered ``stable'' and, 
specifically, the available data suggests that the current number of 
ship strikes is not likely to have an adverse impact on the population, 
despite the fact that it exceeds PBR, with the Navy's minimal 
additional mortality of one whale in the seven years not creating the 
likelihood of adverse impact. Immediately below, we explain the 
information that supports our finding that the Navy's authorized M/SI 
is not expected to result in more than a negligible impact on this 
stock. As described previously, NMFS must also ensure that impacts by 
the applicant on the species or stock from other types of take (i.e., 
harassment) do not combine with the impacts from mortality to adversely 
affect the species or stock via impacts on annual rates of recruitment 
or survival, which occurs further below in the stock-specific 
discussion sections.
    As discussed in the 2018 HSTT final rule, the 2018 final SAR and 
2019 draft SAR rely on a new method to estimate annual deaths by ship 
strike utilizing an encounter theory model that combined species 
distribution models of whale density, vessel traffic characteristics, 
and whale movement patterns obtained from satellite-tagged animals in 
the region to estimate encounters that would result in mortality 
(Rockwood et al., 2017). The model predicts 18 annual mortalities of 
blue whales from vessel strikes, which, with the additional M/SI of 
1.44 from fisheries interactions, results in the current estimate of 
residual PBR equal to -17.3. Although NMFS' Permits and Conservation 
Division in the Office of Protected Resources has independently 
reviewed the new ship strike model and its results and agrees that it 
is appropriate for estimating blue whale mortality by ship strike on 
the U.S. West Coast, for analytical purposes we also note that if the 
historical method were used to predict vessel strike (i.e., using 
observed mortality by vessel strike, or 0.4, instead of 18), then total 
human-caused mortality including the Navy's potential take would not 
exceed PBR. We further note that the authors (Rockwood et al., 2017) do 
not suggest that ship strike suddenly increased to 18 recently. In 
fact, the model is not specific to a year, but rather offers a 
generalized prediction of ship strike off the U.S. West Coast. 
Therefore, if the Rockwood et al. (2017) model is an accurate 
representation of vessel strike, then similar levels of ship strike 
have been occurring in past years as well. Put another way, if the 
model is correct, for some number of years total-human-caused mortality 
has been significantly underestimated and PBR has been similarly 
exceeded by a notable amount, and yet the Eastern North Pacific stock 
of blue whales remains stable nevertheless.
    NMFS' 2018 final SAR and 2019 draft SAR state that the stock is 
``stable'' and there is no indication of a population size increase in 
this blue whale population since the early 1990s. The lack of a 
species' or stock's population increase can have several causes, some 
of which are positive. The SAR further cites to Monnahan et al. (2015), 
which used a population dynamics model to estimate that the Eastern 
North Pacific blue whale population was at 97 percent of carrying 
capacity in 2013, suggesting that the observed lack of a population 
increase since the early 1990s was explained by density dependence, not 
impacts from ship strike. This would mean that this stock of blue 
whales shows signs of stability and is not increasing in population 
size because the population size is at or nearing carrying capacity for 
its available habitat. In fact, we note that this population has 
maintained this status throughout the years that the Navy has 
consistently tested and trained at similar levels (with similar vessel 
traffic) in areas that overlap with blue whale occurrence, which would 
be another indicator of population stability.
    Monnahan et al. (2015) modeled vessel numbers, ship strikes, and 
the population of the Eastern North Pacific blue whale population from 
1905 out to 2050 using a Bayesian framework to incorporate informative 
biological information and assign probability distributions to 
parameters and derived quantities of interest. The authors tested 
multiple scenarios with differing assumptions, incorporated 
uncertainty, and further tested the sensitivity of multiple variables. 
Their results indicated that there is no immediate threat (i.e., 
through 2050) to the population from any of the scenarios tested, which 
included models with 10 and 35 strike mortalities per year. Broadly, 
the authors concluded that, unlike other blue whale stocks, the Eastern 
North Pacific blue whales have recovered from 70 years of whaling and 
are in no immediate threat from ship strikes. They further noted that 
their conclusion conflicts with the depleted and strategic designation 
under the MMPA, as well as PBR specifically.
    As discussed, we also take into consideration management measures 
in place to address M/SI caused by other activities. The Channel 
Islands NMS staff coordinates, collects, and monitors whale sightings 
in and around the Whale Advisory Zone and the Channel Islands NMS 
region. Redfern et al. (2013) note that the areas of highest risk for 
blue whales is the Santa Barbara Channel, where shipping lanes 
intersect with common feeding areas. The seasonally established Whale 
Advisory Zone spans from Point Arguello to Dana Point, including the 
Traffic Separation Schemes in the Santa Barbara Channel and San Pedro 
Channel. Vessels transiting the area from June through November are 
recommended to exercise caution and voluntarily reduce speed to 10 kn 
or less for blue, humpback, and fin whales. Channel Island NMS 
observers collect information from aerial surveys conducted by NOAA, 
the U.S. Coast Guard, California Department of Fish and Game, and U.S. 
Navy chartered aircraft. Information on seasonal presence, movement, 
and general distribution patterns of large whales is shared with 
mariners, NMFS Office of Protected Resources, U.S. Coast Guard, 
California Department of Fish and Game, the Santa Barbara Museum of 
Natural History, the Marine Exchange of Southern California, and whale

[[Page 41872]]

scientists. Real time and historical whale observation data collected 
from multiple sources can be viewed on the Point Blue Whale Database.
    In this case, 0.14 M/SI annually means one mortality in one of the 
seven years and zero mortalities in six of those seven years. 
Therefore, the Navy would not be contributing to the total human-caused 
mortality at all in six of the seven, or 85.7 percent, of the years 
covered by this rule. That means that even if a blue whale were to be 
struck, in six of the seven years there could be no effect on annual 
rates of recruitment or survival from Navy-caused M/SI. Additionally, 
as with humpback whales discussed previously, the loss of a male would 
have far less, if any, effect on population rates and absent any 
information suggesting that one sex is more likely to be struck than 
another, we can reasonably assume that there is a 50 percent chance 
that the single strike authorized by this rule would be a male, thereby 
further decreasing the likelihood of impacts on the population rate. In 
situations like this where potential M/SI is fractional, consideration 
must be given to the lessened impacts anticipated due to the absence of 
M/SI in six of the seven years and the fact that the single strike 
could be a male. Lastly, as with the CA/OR/WA stock of humpback whales 
above, we reiterate that PBR is a conservative metric and also not 
sufficiently precise to serve as an absolute predictor of population 
effects upon which mortality caps would appropriately be based. This is 
especially important given the minor difference between zero and one 
across the seven-year period covered by this rule, which is the 
smallest distinction possible when considering mortality. As noted 
above, Wade et al. (1998), authors of the paper from which the current 
PBR equation is derived, note that ``Estimating incidental mortality in 
one year to be greater than the PBR calculated from a single abundance 
survey does not prove the mortality will lead to depletion; it 
identifies a population worthy of careful future monitoring and 
possibly indicates that mortality-mitigation efforts should be 
initiated.'' The information included here indicates that this blue 
whale stock is stable, approaching carrying capacity, and has leveled 
off because of density-dependence, not human-caused mortality, in spite 
of what might be otherwise indicated from the calculated PBR. Further, 
potential (and authorized) M/SI is below 10 percent of PBR and 
management actions are in place to minimize ship strike from other 
vessel activity in one of the highest-risk areas for strikes. Based on 
all of the considerations described above, we do not expect lethal take 
from Navy activities, alone, to adversely affect Eastern North Pacific 
blue whales through effects on annual rates of recruitment or survival. 
Nonetheless, the fact that total human-caused mortality exceeds PBR 
necessitates close attention to the remainder of the impacts (i.e., 
harassment) on the Eastern North Pacific stock of blue whales from the 
Navy's activities to ensure that the total authorized takes have a 
negligible impact on the species or stock. Therefore, this information 
will be considered in combination with our assessment of the impacts of 
authorized harassment takes in the Group and Species-Specific Analyses 
section that follows.

Group and Species-Specific Analyses

    In addition to broader analyses of the impacts of the Navy's 
activities on mysticetes, odontocetes, and pinnipeds, the 2018 HSTT 
final rule contained detailed analyses of the effects of the Navy's 
activities in the HSTT Study Area on each affected species and stock. 
All of that information and analyses remain applicable and valid for 
our analyses of the effects of the same Navy activities on the same 
species and stocks for the seven-year period of this rule. See the 
Group and Species-Specific Analyses subsection in the Analysis and 
Negligible Impact Determination section of the 2018 HSTT final rule (83 
FR 66993-67018; December 27, 2018). In addition, no new information has 
been received since the publication of the 2018 HSTT final rule that 
significantly changes the analyses on the effects of the Navy's 
activities on each species and stock presented in the 2018 HSTT final 
rule (the potential impact of the new gray whale UME and the corrected 
numbers from the humpback whale SARs were discussed earlier in the 
rule).
    In the discussions below, the estimated Level B harassment takes 
represent instances of take, not the number of individuals taken (the 
much lower and less frequent Level A harassment takes are far more 
likely to be associated with separate individuals), and in many cases 
some individuals are expected to be taken more than one time, while in 
other cases a portion of individuals will not be taken at all. Below, 
we compare the total take numbers (including PTS, TTS, and behavioral 
disruption) for species or stocks to their associated abundance 
estimates to evaluate the magnitude of impacts across the species or 
stock and to individuals. Specifically, when an abundance percentage 
comparison is below 100, it means that that percentage or less of the 
individuals in the stock will be affected (i.e., some individuals will 
not be taken at all), that the average for those taken is one day per 
year, and that we would not expect any individuals to be taken more 
than a few times in a year. When it is more than 100 percent, it means 
there will definitely be some number of repeated takes of individuals. 
For example, if the percentage is 300, the average would be each 
individual is taken on three days in a year if all were taken, but it 
is more likely that some number of individuals will be taken more than 
three times and some number of individuals fewer times or not at all. 
While it is not possible to know the maximum number of days across 
which individuals of a stock might be taken, in acknowledgement of the 
fact that it is more than the average, for the purposes of this 
analysis, we assume a number approaching twice the average. For 
example, if the percentage of take compared to the abundance is 800, we 
estimate that some individuals might be taken as many as 16 times. 
Those comparisons are included in the sections below. For some stocks 
these numbers have been adjusted slightly (with these adjustments being 
in the single digits) so as to more consistently apply this approach, 
but these minor changes did not change the analysis or findings.
    To assist in understanding what this analysis means, we clarify a 
few issues related to estimated takes and the analysis here. In the 
annual estimated take tables below, takes within the U.S. EEZ include 
only those takes within the U.S. EEZ, where most Navy activities occur 
and where we often have the best information on species and stock 
presence and abundance. Takes inside and outside the EEZ include all 
takes in the HSTT Study Area.
    An individual that incurs a PTS or TTS take may sometimes also be 
subject to behavioral disturbance at the same time. As described in the 
Harassment subsection of the Analysis and Negligible Impact 
Determination section of the 2018 HSTT final rule, 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 accrues PTS or 
TTS and is subject to behavioral disturbance would result in impacts to 
reproduction or survival. Nonetheless, we recognize that if an 
individual is subjected to behavioral disturbance repeatedly for a 
longer duration and on consecutive

[[Page 41873]]

days, effects could accrue to the point that reproductive success is 
jeopardized (as discussed below in the stock-specific summaries). 
Accordingly, in analyzing the number of takes and the likelihood of 
repeated and sequential takes (which could result in reproductive 
impacts), 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. We note that the same reasoning applies with the potential 
addition of behavioral disruption to tissue damage from explosives, the 
difference being that we do already consider the likelihood of 
reproductive impacts whenever tissue damage occurs. Further, the number 
of Level A harassment takes by either PTS or tissue damage are so low 
compared to abundance numbers that it is considered highly unlikely 
that any individual would be taken at those levels more than once.
    As noted previously, we presented a detailed discussion of 
important marine mammal habitat (e.g., ESA-designated critical habitat, 
biologically important areas (BIAs), and national marine sanctuaries 
(NMSs)) for all species and stocks in the HSTT Study Area in the 2018 
HSTT proposed final rules. All of that information remains valid and 
applicable to the species- and stock-specific negligible impact 
analyses below. Please see the 2018 rules for complete information. In 
addition, since publication of the 2018 HSTT final rule, NMFS published 
a proposed rule to designate ESA critical habitat for the Central 
America and Mexico DPSs of humpback whales on October 9, 2019 (84 FR 
54354). In the proposed rule only critical habitat Unit 19 overlapped 
with the HSTT Study Area, and NMFS proposed to exclude this unit from 
the critical habitat designation based on consideration of national 
security. A final rule designating critical habitat for these two DPSs 
of humpback whales has not been published.
    All species in the HSTT Study Area will benefit from the procedural 
mitigation measures summarized in the Mitigation Measures section of 
this rule, and described in detail in the Mitigation Measures section 
of the 2018 HSTT final rule. Additionally, the Navy will limit 
activities and employ other measures in mitigation areas that will 
avoid or reduce impacts to several species and stocks. These mitigation 
areas and the associated limitations on activities are summarized in 
Table 15 above and described in detail in the Mitigation Measures 
section of the 2018 HSTT final rule. The manner and extent to which the 
limitations in these mitigation areas will prevent or minimize 
potential impacts on specific species and stocks in the HSTT Study Area 
is discussed in the Mitigation Measures section of the 2018 HSTT final 
rule under Final Mitigation Areas, all of which remains valid and 
applicable for this final rule.
    Having considered all of the information and analyses previously 
presented in the 2018 HSTT final rule, including the Group and Species-
Specific Analyses discussions organized by the different groups and 
species, below we present tables showing instances of total take as a 
percentage of stock abundance for each group, updated with the new 
explosion and vessel strike calculations. We then summarize the 
information for each species or stock, considering the analysis from 
the 2018 HSTT final rule and any new analysis. 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 
and pinnipeds in water), 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 or stock. In addition, animals 
belonging to each stock within a species typically have the same 
hearing capabilities and behaviorally respond in the same manner as 
animals in other stocks within the species.
Mysticetes
    In Tables 18 and 19 below for mysticetes, we indicate the total 
annual mortality, Level A harassment, Level B harassment, and a number 
indicating the instances of total take as a percentage of abundance. 
Tables 18 and 19 have been updated from Tables 71 and 72 in the 2018 
HSTT final rule as appropriate with the 2018 final SARs and 2019 draft 
SARs and updated information on mortality, as discussed above. For 
additional information and analysis supporting the negligible-impact 
analysis, see the Mysticetes discussion in the Group and Species-
Specific Analyses section of the 2018 HSTT final rule, all of which 
remains applicable to this final rule unless specifically noted.

 Table 18--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Mysticetes in the HRC Portion of the HSTT Study Area and Number Indicating the Instances of Total Take as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Instances of indicated types of incidental take  (not all takes         Total takes                Abundance            Instance of total take as
                                                                                       represent separate individuals, especially for disturbance)   ----------------------------------------------------      percent of abundance
                                                                                   ------------------------------------------------------------------                                                    -------------------------------
                                                                                        Level B harassment        Level A harassment                                             Total Navy
                    Species                                    Stock               -----------------------------------------------------              Total takes     Takes      abundance    Within EEZ   Total take as    EEZ take as
                                                                                                   TTS (may                                             (entire      (within     inside and      Navy      percentage of   percentage of
                                                                                     Behavioral      also                      Tissue     Mortality   study area)   Navy EEZ)    outside of   abundance     total Navy       Navy EEZ
                                                                                    disturbance     include        PTS         damage                                            EEZ (HRC)      (HRC)        abundance       abundance
                                                                                                 disturbance)                                                                                                  (HRC)           (HRC)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale.....................................  Central North Pacific............           15            33            0            0            0           48           40           43           33             112             121
Bryde's whale..................................  Hawaii...........................           40           106            0            0            0          146          123          108           89             135             138
Fin whale......................................  Hawaii...........................           21            27            0            0            0           48           41           52           40              92             103
Humpback whale.................................  Central North Pacific............        2,837         6,289            3            0         0.29        9,129        7,389        5,078        4,595             180             161
Minke whale....................................  Hawaii...........................        1,233         3,697            2            0            0        4,932        4,030        3,652        2,835             135             142
Sei whale......................................  Hawaii...........................           46           121            0            0            0          167          135          138          107             121             126
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the HI take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule), both
  in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area used to generate the abundance estimates in the SARs, and the abundance predicted by the same
  underlying density estimates is the preferred abundance to use, there is no need to separately compare the take to the SARs abundance estimate.
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.
The annual mortality of 0.29 is the result of no more than two mortalities over the course of seven years from vessel strikes as described above in the Estimated Take of Marine Mammals section.


[[Page 41874]]


   Table 19--Annual estimated takes by Level B harassment, Level A harassment, and mortality for mysticetes in the SOCAL portion of the HSTT Study Area and number indicating the instances of
                                                                         total take as a percentage of stock abundance.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Instances of indicated types of incidental take  (not all takes  Total takes          Abundance            Instance of total take as
                                                            represent separate individuals, especially for disturbance)   ---------------------------------------      percent of abundance
                                                        ------------------------------------------------------------------                                       -------------------------------
                                                             Level B harassment        Level A harassment                                   Navy                   Total take as
             Species                       Stock        -----------------------------------------------------              Total takes   abundance    NMFS SARS    percentage of   Total take as
                                                                        TTS (may                               Mortality     (entire     in Action    abundance     total Navy     percentage of
                                                          Behavioral  also include      PTS         Tissue                 Study Area)      Area                   abundance in      total SAR
                                                         disturbance  disturbance)                  damage                                (SOCAL)                   Action Area      abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale.......................  Eastern North                 792         1,196            1            0         0.14        1,989          785        1,496             253             133
                                    Pacific.
Bryde's whale....................  Eastern Tropical               14            27            0            0            0           41            1      unknown           3,154         unknown
                                    Pacific.
Fin whale........................  CA/OR/WA............          835         1,390            1            0         0.29        2,226          363        9,029             613              25
Humpback whale...................  CA/OR/WA............          480         1,514            1            0         0.14        1,995          247        2,900             808              69
Minke whale......................  CA/OR/WA............          259           666            1            0            0          926          163          636             568             146
Sei whale........................  Eastern North                  27            52            0            0            0           79            3          519           2,633              15
                                    Pacific.
Gray whale.......................  Eastern North               1,316         3,355            7            0         0.29        4,678          193       26,960           2,424              17
                                    Pacific.
Gray whale.......................  Western North                   2             4            0            0            0            6            0          290               0               2
                                    Pacific.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
  and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
  predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.
The annual mortality of 0.14 is the result of no more than one mortality over the course of seven years from vessel strikes as described above in the Estimated Take of Marine Mammals section.
  The annual mortality of 0.29 is the result of no more than two mortalities over the course of seven years from vessel strikes.

    Below we compile and summarize the information that supports our 
determination that the Navy's activities will not adversely affect any 
species or stocks through effects on annual rates of recruitment or 
survival for any of the affected mysticete stocks.

Blue Whale (Eastern North Pacific Stock)

    The SAR identifies this stock as ``stable'' even though the larger 
species is listed as endangered under the ESA. We further note that 
this species was originally listed under the ESA as a result of the 
impacts from commercial whaling, which is no longer affecting the 
species. No Level A harassment by tissue damage is anticipated or 
authorized. NMFS will authorize one mortality over the seven years 
covered by this rule, or 0.14 mortality annually. With the addition of 
this 0.14 annual mortality, residual PBR is exceeded, resulting in the 
total human-caused mortality exceeding PBR by 17.44. However, as 
described in more detail in the Serious Injury or Mortality section 
above, when total human-caused mortality exceeds PBR, we consider 
whether the incremental addition of a small amount of authorized 
mortality from the specified activity may still result in a negligible 
impact, in part by identifying whether it is less than 10 percent of 
PBR. In this case, the authorized mortality is well below 10 percent of 
PBR, management measures are in place to reduce mortality from other 
sources, and the incremental addition of a single mortality over the 
course of the seven-year Navy rule is not expected to, alone, lead to 
adverse impacts on the stock through effects on annual rates of 
recruitment or survival. In addition, even with the additional two 
years of activities under this rule, no additional M/SI is estimated 
for this stock, leading to a slight decrease (from 0.2 to 0.14 
annually) in annual mortality from the 2018 HSTT final rule.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the Navy-estimated 
abundance and the SAR) is 253 and 133 percent, respectively. Given the 
range of blue whales, this information suggests that only some smaller 
portion of individuals in the stock are likely impacted, but that there 
will likely be some repeat exposure (maybe 5 or 6 days within a year) 
of some subset of individuals that spend extended time within the SOCAL 
Range. Some of these takes could occur on a few sequential days for 
some small number of individuals, for example, if they resulted from a 
multi-day exercise on a range while individuals were in the area for 
multiple days feeding. However, these amounts are still not expected to 
adversely impact reproduction or survival of any individuals. Regarding 
the severity of those individual Level B harassment takes by behavioral 
disruption, 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). 
Additionally, the Navy implements time/area mitigation in SOCAL in the 
majority of the BIAs, which will reduce the severity of impacts to blue 
whales by reducing interference in feeding that could result in lost 
feeding opportunities or necessitate additional energy expenditure to 
find other good opportunities. Regarding the severity of TTS takes, we 
have explained in the 2018 HSTT final rule that they are expected to be 
low-level, of short duration, and mostly not in a frequency band that 
would be expected to interfere with blue whale communication or other 
important low-frequency cues--and the associated lost opportunities and 
capabilities are not at a level that will impact reproduction or 
survival. For similar reasons (as described in the 2018 HSTT final 
rule) the single estimated Level A harassment take by PTS for this 
stock is unlikely to have any effect on the reproduction or survival of 
that one individual, even if it were to be experienced by an animal 
that also experiences one or more Level B harassment takes by 
behavioral disruption.
    Altogether, this population is stable, only a smaller portion of 
the stock is anticipated to be impacted, and any individual blue whale 
is likely to be disturbed at a low-moderate level, with likely many 
animals exposed only once or twice and a subset potentially disturbed 
across five or six days, but minimized in biologically important areas. 
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. One individual is expected to be taken by PTS annually of 
likely low severity. A small permanent loss of hearing sensitivity

[[Page 41875]]

(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 one Level A harassment take by 
PTS would be unlikely to impact behaviors, opportunities, or detection 
capabilities to a degree that would interfere with reproductive success 
or survival of that individual, let alone have effects on annual rates 
of recruitment or survival. Nor are these harassment takes combined 
with the one authorized mortality (which our earlier analysis indicated 
will not have more than a negligible impact on this stock of blue 
whales), expected to adversely affect this stock 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 the Eastern North Pacific stock of blue whales.

Bryde's Whale (Eastern Tropical Pacific Stock)

    Little is known about this stock, or its status, and it is not 
listed under the ESA. No mortality or Level A harassment is anticipated 
or authorized. 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 3,154 percent, however, the abundance 
upon which this percentage is based (1.3 whales from the Navy estimate, 
which is extrapolated from density estimates based on very few 
sightings) is clearly erroneous and the SAR does not include an 
abundance estimate because all of the survey data is outdated (Table 
19). However, the abundance in the early 1980s was estimated as 22,000 
to 24,000, a portion of the stock was estimated at 13,000 in 1993, and 
the minimum number in the Gulf of California alone was estimated at 160 
in 1990. Given this information and there being no indication of 
dramatic decline since these population estimates, along with the fact 
that 41 total takes of Bryde's whales were estimated, this information 
suggests that only a small portion of the individuals in the stock are 
likely to be impacted, and few, if any, are likely to be taken over 
more than one day. Regarding the severity of those individual Level B 
harassment takes by behavioral disruption, 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 Bryde's whale 
communication or other important low-frequency cues. Any associated 
lost opportunities and capabilities are not at a level that will impact 
reproduction or survival.
    Altogether, in spite of the unknown status and calculated number of 
instances of take compared to abundance, only a small portion of the 
stock is anticipated to be impacted based on the more likely minimum 
population level and any individual Bryde's whale is likely to be 
disturbed at a low-moderate level, with few, if any, individuals 
exposed over more than one day in the year. No mortality and no Level A 
harassment is anticipated or proposed for authorization. This low 
magnitude and severity of harassment effects is not expected to result 
in impacts on individual reproduction or survival, much less 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 the Eastern Tropical Pacific stock of Bryde's whales.

Fin Whale (CA/OR/WA Stock)

    The SAR identifies this stock as ``increasing,'' even though the 
larger species is listed as endangered under the ESA. No Level A 
harassment by tissue damage is anticipated or authorized. NMFS 
authorizes two mortalities over the seven years covered by this rule, 
or 0.29 mortality annually. The addition of this 0.29 annual mortality 
still leaves the total human-caused mortality well under the 
insignificance threshold of residual PBR. In addition, even with the 
additional two years of activities under this rule, no additional M/SI 
is estimated for this stock, leading to a slight decrease (from 0.4 to 
0.29 annually) in annual mortality from the 2018 HSTT final rule.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the Navy-estimated 
abundance and the SAR) is 613 and 25 percent, respectively. This 
information suggests that only some portion (less than 25 percent) of 
individuals in the stock are likely impacted, but that there is likely 
some repeat exposure (perhaps up to 12 days within a year) of some 
subset of individuals that spend extended time within the SOCAL 
complex. Some of these takes could occur on a few sequential days for 
some small number of individuals, for example, if they resulted from a 
multi-day exercise on a range while individuals were in the area for 
multiple days feeding. However, these amounts are still not expected to 
adversely impact reproduction or survival of any individuals. Regarding 
the severity of those individual Level B harassment takes by behavioral 
disruption, 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). 
Additionally, while there are no BIAs for fin whales in the SOCAL 
range, the Navy implements time/area mitigation in SOCAL in blue whale 
BIAs, and fin whales are known to sometimes feed in some of the same 
areas, which means they could potentially accrue some benefits from the 
mitigation. 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 fin whale communication or 
other important low-frequency cues--and the associated lost 
opportunities and capabilities are not at a level that will impact 
reproduction or survival. For similar reasons (as described in the 2018 
HSTT final rule) the single estimated Level A harassment take by PTS 
for this stock is unlikely to have any effects on the reproduction or 
survival of that one individual, even if it were to be experienced by 
an animal that also experiences one or more Level B harassment takes by 
behavioral disruption.
    Altogether, this population is increasing, only a small portion of 
the stock is anticipated to be impacted, and any individual fin whale 
is likely to be disturbed at a low-moderate level, with the taken 
individuals likely exposed between one and twelve days, with a few 
individuals potentially taken on a few sequential days. This low 
magnitude and severity of harassment effects is not expected to result 
in impacts on the reproduction or survival for any individuals, let 
alone have impacts on annual rates of recruitment or survival. One 
individual is expected to be taken by PTS annually 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

[[Page 41876]]

the estimated one Level A harassment take by PTS would be unlikely to 
impact behaviors, opportunities, or detection capabilities to a degree 
that would interfere with reproductive success or survival of that 
individual, let alone have effects on annual rates of recruitment or 
survival. Nor are these harassment takes combined with the two 
authorized mortalities expected to adversely affect this stock 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 the CA/OR/WA stock of fin whales.

Humpback Whale (CA/OR/WA Stock)

    The SAR identifies this stock as stable (having shown a long-term 
increase from 1990 and then leveling off between 2008 and 2014) and the 
individuals in this stock are associated with three DPSs, one of which 
is not listed under the ESA (Hawaii), one of which is listed as 
threatened (Mexico), and one of which is listed as endangered (Central 
America). Individuals encountered in the SOCAL portion of the HSTT 
Study Area are likely to come from the latter two DPSs. No Level A 
harassment by tissue damage is anticipated or authorized. NMFS 
authorizes one mortality over the seven years covered by this rule, or 
0.14 mortality annually (Mexico DPS only). With the addition of this 
0.14 annual mortality, the total human-caused mortality exceeds PBR by 
8.84. However, as described in more detail in the Serious Injury or 
Mortality section, when total human-caused mortality exceeds PBR, we 
consider whether the incremental addition of a small amount of 
authorized mortality from the specified activity may still result in a 
negligible impact, in part by identifying whether it is less than 10 
percent of PBR, which is 33.4. In this case, the authorized mortality 
is well below 10 percent of PBR (less than one percent, in fact) and 
management measures are in place to reduce mortality from other 
sources. More importantly, as described above in the Serious Injury or 
Mortality section, the authorized mortality of 0.14 will not delay the 
time to recovery by more than 1 percent. Given these considerations 
along with those discussed earlier, the incremental addition of a 
single mortality over the course of the seven-year Navy rule is not 
expected to, alone, lead to adverse impacts on the stock through 
effects on annual rates of recruitment or survival. In addition, even 
with the additional two years of activities under this rule, no 
additional M/SI is estimated for this stock, leading to a slight 
decrease (from 0.2 to 0.14 annually) in annual mortality from the 2018 
HSTT final rule.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the Navy-estimated 
abundance and the SAR) is 808 and 69 percent, respectively. Given the 
range of humpback whales, this information suggests that only some 
portion of individuals in the stock are likely impacted, but that there 
is likely some repeat exposure (perhaps up to 16 days within a year) of 
some subset of individuals that spend extended time within the SOCAL 
complex. Regarding the severity of those individual Level B harassment 
takes by behavioral disruption, 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). Some of these takes could occur on several sequential days 
for some small number of individuals, for example, if they resulted 
from a multi-day exercise on a range while individuals were in the area 
for multiple days feeding. However, these amounts are still not 
expected to adversely impact reproduction or survival of any 
individuals.
    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 humpback whale communication or other 
important low-frequency cues--and the associated lost opportunities and 
capabilities are not at a level that will impact reproduction or 
survival. For similar reasons (as described in the 2018 HSTT final 
rule) the single estimated Level A harassment take by PTS for this 
stock is unlikely to have any effects on the reproduction or survival 
of that one individual, even if it were to be experienced by an animal 
that also experiences one or more Level B harassment takes by 
behavioral disruption.
    Altogether, this population is stable, only a small portion of the 
stock is anticipated to be impacted and any individual humpback whale 
is likely to be disturbed at a low-moderate level, with likely many 
animals exposed only once or twice and a subset potentially disturbed 
up to 16 days, but with no reason to think that more than several of 
those days would be sequential. 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. One individual is expected to 
be taken by PTS annually 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 one 
Level A harassment take by PTS would be unlikely to impact behaviors, 
opportunities, or detection capabilities to a degree that would 
interfere with reproductive success or survival of that individual, let 
alone have effects on annual rates of recruitment or survival. Nor are 
these harassment takes combined with the one authorized mortality 
(which our earlier analysis indicated will not have more than a 
negligible impact on this stock of humpback whales) expected to 
adversely affect this stock 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 the CA/OR/WA 
stock of humpback whales.

Minke Whale (CA/OR/WA Stock)

    The status of this stock is unknown and it is not listed under the 
ESA. No mortality from vessel strike or Level A harassment by tissue 
damage from explosive exposure is anticipated or authorized for this 
species. Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the Navy-estimated 
abundance and the SAR) is 568 and 146 percent, respectively. Based on 
the behaviors of minke whales, which often occur along continental 
shelves and sometimes establish home ranges along the West Coast, this 
information suggests that only a portion of individuals in the stock 
are likely impacted, but that there is likely some repeat exposure 
(perhaps up to 11 days within a year) of some subset of individuals 
that spend extended time within the SOCAL complex. Some of these takes 
could occur on a few sequential days for some small number of 
individuals, for example, if they resulted from a multi-day exercise on 
a range while individuals were in the area for multiple days feeding. 
However, these amounts are still not expected to adversely impact 
reproduction or survival of any individuals. Regarding the severity of

[[Page 41877]]

those individual Level B harassment takes by behavioral disruption, 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 minke 
whale communication or other important low-frequency cues--and the 
associated lost opportunities and capabilities are not at a level that 
will impact reproduction or survival. For similar reasons (as described 
in the 2018 HSTT final rule) the single estimated Level A harassment 
take by PTS for this stock is unlikely to have any effects on the 
reproduction or survival of that individual, even if it were to be 
experienced by an animal that also experiences one or more Level B 
harassment takes by behavioral disruption.
    Altogether, while the status of this population is unknown, only a 
portion of the stock is anticipated to be impacted and any individual 
minke whale is likely to be disturbed at a low-moderate level, with the 
taken individuals likely exposed between one and eleven days, with a 
few individuals potentially taken on a few sequential days. No 
mortality is anticipated or proposed for authorization. This low 
magnitude and 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. One individual is 
expected to be taken by PTS annually 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 one Level A harassment take by PTS would be unlikely to 
impact behaviors, opportunities, or detection capabilities to a degree 
that would interfere with reproductive success or survival of that 
individual, let alone have effects 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 the CA/OR/WA stock of 
minke whales.

Sei Whale (Eastern North Pacific Stock)

    The status of this stock is unknown and it is listed as endangered 
under the ESA. No mortality or Level A harassment is anticipated or 
authorized. Regarding the magnitude of Level B harassment takes (TTS 
and behavioral disruption), the number of estimated total instances of 
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is 2,633 and 15 percent, respectively, 
however, the abundance upon which the Navy percentage is based (3 from 
the Navy estimate, which is extrapolated from density estimates based 
on very few sightings) is likely an underestimate of the number of 
individuals in the HSTT Study Area, resulting in an overestimated 
percentage. Given this information and the large range of sei whales, 
and the fact that only 79 total Level B harassment takes of sei whales 
were estimated, it is likely that some very small number of sei whales 
would be taken repeatedly, potentially up to 15 days in a year 
(typically 2,633 percent would lead to the estimate of 52 days/year, 
however, given that there are only 79 sei whale total takes, we used 
the conservative assumption that five individuals might be taken up to 
15 times, with the few remaining takes distributed among other 
individuals). Regarding the severity of those individual Level B 
harassment takes by behavioral disruption, 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). Some of these takes could occur on a few sequential 
days for some small number of individuals, for example, if they 
resulted from a multi-day exercise on a range while individuals were in 
the area for multiple days feeding, however, these amounts are still 
not expected to adversely impact reproduction or survival of any 
individuals. 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 sei whale communication or 
other important low-frequency cues--and the associated lost 
opportunities and capabilities are not at a level that will impact 
reproduction or survival.
    Altogether, while the status of this population is unknown, only a 
small portion of the stock is anticipated to be impacted and any 
individual sei whale is likely to be disturbed at a low-moderate level, 
with only a few individuals exposed over one to 15 days in a year, with 
no more than a few sequential days. 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 individual 
reproduction or survival, much less annual rates of recruitment or 
survival for the stock. 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 the Eastern 
North Pacific stock of sei whales.

Gray Whale (Eastern North Pacific Stock)

    The SAR identifies this stock as ``increasing'' and the species is 
not listed under the ESA. No Level A harassment by tissue damage is 
anticipated or authorized. NMFS is authorizing two mortalities over the 
seven years covered by this rule, or 0.29 mortality annually. The 
addition of this 0.29 annual mortality still leaves the total human-
caused mortality well under the insignificance threshold of residual 
PBR (663). On May 31, 2019, NMFS declared the unusual spike in 
strandings of gray whales along the west coast of North America since 
January 1, 2019 an UME. As of March 13, 2020, 264 gray whales have 
stranded along the west coast of North America (in the U.S., Canada, 
and Mexico). Including these mortalities in the calculated residual PBR 
still leaves the addition of 0.29 annual mortality well under the 
insignificance threshold of residual PBR (399 including known deaths 
due to the UME). In addition, even with the additional two years of 
activities under this rule, no additional M/SI is estimated for this 
stock, leading to a slight decrease (from 0.4 to 0.29 annually) in 
annual mortality from the 2018 HSTT final rule.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the Navy-estimated 
abundance and the SAR) is 2,424 and 17 percent, respectively. This 
information suggests that only some small portion of individuals in the 
stock are likely impacted (less than 17 percent), but that there is 
likely some level of repeat exposure of some subset of individuals that 
spend extended time within the SOCAL complex. Typically, 2,424 percent 
would lead to the estimate of 48 days/year, however, given that a large 
number of gray whales are known to migrate through the SOCAL complex 
and the fact that there are 4,678 total takes, we believe that it is 
more likely that a larger number of individuals would be taken one to a 
few times,

[[Page 41878]]

while a small number staying in an area to feed for several days may be 
taken on 5-10 days. Regarding the severity of those individual Level B 
harassment takes by behavioral disruption, 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). Some of these takes could occur on a few sequential 
days for some small number of individuals, however, these amounts are 
still not expected to adversely impact reproduction or survival of any 
individuals.
    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 gray whale communication or other 
important low-frequency cues, and the associated lost opportunities and 
capabilities are not at a level that will impact reproduction or 
survival. For these same reasons (low level and frequency band), while 
a small permanent loss of hearing sensitivity may include some degree 
of energetic costs for compensating or may mean some small loss of 
opportunities or detection capabilities, at the expected scale the 7 
estimated Level A harassment takes by PTS for gray whales will be 
unlikely to impact behaviors, opportunities, or detection capabilities 
to a degree that would interfere with reproductive success or survival 
of any individuals, even if it were to be experienced by an animal that 
also experiences one or more Level B harassment takes by behavioral 
disruption.
    Altogether, while we have considered the impacts of the gray whale 
UME, gray whales are not endangered or threatened under the ESA and the 
Eastern North Pacific stock is increasing. Only a small portion of the 
stock is anticipated to be impacted and any individual gray whale is 
likely to be disturbed at a low-moderate level, with likely many 
animals exposed only once or twice and a subset potentially disturbed 
across five to ten days. This low magnitude and severity of harassment 
effects is not expected to result in impacts to reproduction or 
survival for any individuals, let alone have impacts on annual rates of 
recruitment or survival. Seven individuals are expected to be taken by 
PTS annually of likely low severity, with this unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
would interfere with reproductive success or survival of those 
individuals, let alone have effects on annual rates of recruitment or 
survival. Nor are these harassment takes combined with the two 
authorized mortalities expected to adversely affect this stock 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 the Eastern North Pacific stock of gray whales.

Gray Whale (Western North Pacific Stock)

    The Western North Pacific stock of gray whales is reported as 
increasing in the 2018 final SAR, but is listed as endangered under the 
ESA. No mortality or Level A harassment is anticipated or 
authorization. This stock is expected to incur the very small number of 
6 Level B harassment takes (2 behavioral disruption and 4 TTS) to a 
stock with a SAR-estimated abundance of 290. These takes will likely 
accrue to different individuals, the behavioral disturbances will be of 
a low-moderate level, and the TTS instances will be at a low level and 
of short duration (with the same expected effects as described for the 
Eastern North Pacific stock of gray whales described above). This low 
magnitude and severity of harassment effects is not expected to result 
in impacts on individual reproduction or survival, much less to 
adversely affect this stock 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 the Western 
North Pacific stock of gray whales.

Humpback Whale (Central North Pacific Stock)

    The 2018 final SAR identifies this stock as ``increasing'' and the 
DPS is not listed under the ESA. No Level A harassment by tissue damage 
is anticipated or authorized. NMFS authorizes two mortalities over the 
seven years covered by this rule, or 0.29 mortalities annually. The 
addition of this 0.29 annual mortality still leaves the total human-
caused mortality well under the insignificance threshold for residual 
PBR. In addition, even with the additional two years of activities 
under this rule, no additional M/SI is estimated for this stock, 
leading to a slight decrease (from 0.4 to 0.29 annually) in annual 
mortality from the 2018 HSTT final rule.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated instances of take 
compared to the abundance, both throughout the HSTT Study Area and 
within the U.S. EEZ, respectively, is 180 and 161 percent. This 
information and the complicated far-ranging nature of the stock 
structure suggests that some portion of the stock (but not all) are 
likely impacted, over one to several days per year, with little 
likelihood of take across sequential days. Regarding the severity of 
those individual Level B harassment takes by behavioral disruption, 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). Additionally, as noted above, 
there are two mitigation areas implemented by the Navy that span a 
large area of the important humpback reproductive area (BIA) and 
minimize impacts by limiting the use of MF1 active sonar and 
explosives, thereby reducing both the number and severity of takes of 
humpback whales. 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 humpback whale communication 
or other important low-frequency cues, and the associated lost 
opportunities and capabilities are not at a level that will impact 
reproduction or survival. For these same reasons (low level and 
frequency band), while a small permanent loss of hearing sensitivity 
may include some degree of energetic costs for compensating or may mean 
some small loss of opportunities or detection capabilities, at the 
expected scale the three estimated Level A harassment takes by PTS for 
humpback whales will be unlikely to impact behaviors, opportunities, or 
detection capabilities to a degree that would interfere with 
reproductive success or survival of any individuals, even if it were to 
be experienced by an animal that also experiences one or more Level B 
harassment takes by behavioral disruption.
    Altogether, this stock is increasing and the DPS is not listed as 
endangered or threatened under the ESA. Only a small portion of the 
stock is anticipated to be impacted and any individual humpback whale 
is likely to be disturbed at a low-moderate level, with the taken 
individuals likely exposed between one to several days per year, with 
little likelihood of take across sequential days. This low magnitude 
and severity of harassment effects is not

[[Page 41879]]

expected to result in impacts on individual reproduction or survival, 
let alone have impacts on annual rates of recruitment or survival. 
Three individuals are estimated to be taken by PTS annually of likely 
low severity, with this unlikely to impact behaviors, opportunities, or 
detection capabilities to a degree that would interfere with 
reproductive success or survival of those individuals, let alone have 
effects on annual rates of recruitment or survival. Nor are these 
harassment takes combined with the two authorized mortalities expected 
to adversely affect this stock 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 the Central 
North Pacific stock of humpback whales.

Blue Whale (Central North Pacific Stock) and the Hawaii Stocks of 
Bryde's Whale, Fin Whale, Minke Whale, and Sei Whale

    The status of these stocks is not identified in the SARs. Blue 
whales, fin whales, and sei whales are listed as endangered under the 
ESA; minke whales and Bryde's whales (other than the Gulf of Mexico 
DPS) are not listed under the ESA. No mortality or Level A harassment 
by tissue damage is anticipated or authorized for any of these stocks.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated instances of take 
compared to the abundance, both throughout the HSTT Study Area and 
within the U.S. EEZ, respectively, is 92-135 and 103-142 percent. This 
information suggests that some portion of the stocks (but not all) are 
likely impacted, over one to several days per year, with little 
likelihood of take across sequential days. Regarding the severity of 
those individual Level B harassment takes by behavioral disruption, 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 
mysticete communication or other important low-frequency cues--and the 
associated lost opportunities and capabilities are not at a level that 
will impact reproduction or survival. For similar reasons (as described 
in the 2018 HSTT final rule) the two estimated Level A harassment takes 
by PTS for the Hawaii stock of minke whales are unlikely to have any 
effects on the reproduction or survival of those two individuals, even 
if it were to be experienced by an animal that also experiences one or 
more Level B harassment takes by behavioral disruption.
    Altogether, while the status of these populations is unknown, only 
a portion of these stocks are anticipated to be impacted and any 
individuals of these stocks are likely to be disturbed at a low-
moderate level, with the taken individuals likely exposed between one 
and several days, with little chance that any are taken across 
sequential days. No mortality is anticipated or authorized for any of 
these stocks. This low magnitude and 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. Two individual minke whales from the Hawaii stock are 
estimated to be taken by PTS annually 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 Level A harassment take by PTS would be unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
would interfere with reproductive success or survival of those 
individuals, let alone have effects 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 stocks.
Odontocetes

Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales

    In Tables 20 and 21 below for sperm whales, dwarf sperm whales, and 
pygmy sperm whales, we indicate the total annual mortality, Level A and 
Level B harassment, and a number indicating the instances of total take 
as a percentage of abundance. Tables 20 and 21 are unchanged from 
Tables 73 and 74 in the 2018 HSTT final rule, except for updated 
information on mortality for the Hawaii stock of sperm whales, as 
discussed above. For additional information and analysis supporting the 
negligible-impact analysis, see the Odontocetes discussion as well as 
the Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales discussion 
in the Group and Species-Specific Analyses section of the 2018 HSTT 
final rule, all of which remains applicable to this final rule unless 
specifically noted.

 Table 20--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales in the HRC Portion of the HSTT Study Area and Number Indicating the Instances of
                                                                                              Total Take as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Instances of indicated types of incidental take  (not all takes         Total takes                Abundance           Instances of total take as
                                                                                       represent separate individuals, especially for disturbance)   ----------------------------------------------------      percent of abundance
                                                                                   ------------------------------------------------------------------                                                    -------------------------------
                                                                                        Level B harassment        Level A harassment                                             Total Navy
                    Species                                    Stock               -----------------------------------------------------              Total takes     Takes      abundance    Within EEZ   Total take as    EEZ take as
                                                                                                   TTS  (may                                            (entire      (within     inside and      Navy      percentage of   percentage of
                                                                                     Behavioral      also                      Tissue     Mortality   study area)   NAVY EEZ)   outside EEZ   abundance     total Navy    EEZ  abundance
                                                                                    disturbance     include        PTS         damage                                               (HRC)       (HRC)        abundance         (HRC)
                                                                                                 disturbance)                                                                                                  (HRC)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Dwarf sperm whale..............................  Hawaii...........................        5,870        14,550           64            0            0       20,484       15,310        8,218        6,379             249             240
Pygmy sperm whale..............................  Hawaii...........................        2,329         5,822           29            0            0        8,180        6,098        3,349        2,600             244             235
Sperm whale....................................  Hawaii...........................        2,466            30            0            0         0.14        2,496        1,317        1,656        1,317             151             147
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the HI take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule), both
  in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area used to generate the abundance estimates in the SARs, and the abundance predicted by the same
  underlying density estimates is the preferred abundance to use, there is no need to separately compare the take to the SARs abundance estimate.
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.

[[Page 41880]]

 
The annual mortality of 0.14 is the result of no more than one mortality over the course of seven years from vessel strikes as described above in the Estimated Take of Marine Mammals section.


  Table 21--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales in the SOCAL portion of the HSTT Study
                                                    Area and Number Indicating the Instances of Total Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Instances of indicated types of incidental take (not all takes   Total takes          Abundance           Instances of total take as
                                                            represent separate individuals, especially for disturbance)   ---------------------------------------      percent of abundance
                                                        ------------------------------------------------------------------                                       -------------------------------
                                                             Level B harassment        Level A harassment
             Species                       Stock        -----------------------------------------------------              Total takes      Navy                   Total take as   Total take as
                                                                        TTS (may                                             (entire     abundance    NMFS SARS    percentage of   percentage of
                                                          Behavioral      also                      Tissue     Mortality   study area)   in action    abundance     total Navy       total SAR
                                                         disturbance     include        PTS         damage                                  area                   abundance in      abundance
                                                                      disturbance)                                                                                  action area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Kogia whales.....................  CA/OR/WA............        2,779         6,353           38            0            0        9,170          757        4,111           1,211             223
Sperm whale......................  CA/OR/WA............        2,437            56            0            0            0        2,493          273        1,997             913             125
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
  and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
  predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.

    Below we compile and summarize the information that supports our 
determination that the Navy's activities will not adversely affect any 
species or stocks through effects on annual rates of recruitment or 
survival for any of the affected stocks addressed in this section.
Sperm Whale, Dwarf Sperm Whale, and Pygmy Sperm Whale (CA/OR/WA Stocks)
    The SAR identifies the CA/OR/WA stock of sperm whales as ``stable'' 
and the species is listed as endangered under the ESA. The status of 
the CA/OR/WA stocks of pygmy and dwarf sperm whales is unknown and 
neither are listed under the ESA. Neither mortality nor Level A 
harassment by tissue damage from exposure to explosives is expected or 
authorized for any of these three stocks.
    Due to their pelagic distribution, small size, and cryptic 
behavior, pygmy sperm whales and dwarf sperm whales (Kogia species) are 
rarely sighted during at-sea surveys and are difficult to distinguish 
between when visually observed in the field. Many of the relatively few 
observations of Kogia species off the U.S. West Coast were not 
identified to species. All at-sea sightings of Kogia species have been 
identified as pygmy sperm whales or Kogia species generally. Stranded 
dwarf sperm and pygmy sperm whales have been found on the U.S. West 
Coast, however dwarf sperm whale strandings are rare. NMFS SARs suggest 
that the majority of Kogia sighted off the U.S. West Coast were likely 
pygmy sperm whales. As such, the stock estimate in the NMFS SAR for 
pygmy sperm whales is the estimate derived for all Kogia species in the 
region (Barlow, 2016), and no separate abundance estimate can be 
determined for dwarf sperm whales, though some low number likely reside 
in the U.S. EEZ. Due to the lack of an abundance estimate it is not 
possible to predict the amount of Level A harassment and Level B 
harassment take of dwarf sperm whales and therefore take estimates are 
identified as Kogia whales (including both pygmy and dwarf sperm 
whales). We assume only a small portion of those takes are likely to be 
dwarf sperm whales as the available information indicates that the 
density and abundance in the U.S. EEZ is low.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the Navy-estimated 
abundance and the SAR) is, respectively, 913 and 125 percent for sperm 
whales and 1,211 and 223 percent for Kogia whales, with a large 
proportion of the Kogia whales anticipated to be pygmy sperm whales due 
to the low abundance and density of dwarf sperm whales in the HSTT 
Study Area. Given the range of these stocks (which extends the entire 
length of the West Coast, as well as beyond the U.S. EEZ boundary), 
this information suggests that some portion of the individuals in these 
stocks will not be impacted, but that there is likely some repeat 
exposure (perhaps up to 24 days within a year for Kogia species and 18 
days a year for sperm whales) of some small subset of individuals that 
spend extended time within the SOCAL Range. Regarding the severity of 
those individual Level B harassment takes by behavioral disruption, 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). Additionally, while interrupted 
feeding bouts are a known response and concern for odontocetes, we also 
know that there are often viable alternative habitat options in the 
relative vicinity. However, some of these takes could occur on a fair 
number of sequential days for some number of individuals.
    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 any of these three species' communication 
or other important low-frequency cues, and that the associated lost 
opportunities and capabilities are not at a level that will impact 
reproduction or survival. For these same reasons (low level and 
frequency band), while 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, at 
the expected scale the estimated Level A harassment takes by PTS for 
the dwarf and pygmy sperm whale stocks will be unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
would interfere with reproductive success or survival of any 
individuals (and no Level A harassment takes are anticipated or 
authorized for sperm whales), even if it were to be experienced by an 
animal that also experiences one or more Level B harassment takes by 
behavioral disruption. Thus the 38 Level A harassment takes by PTS for 
the two Kogia stocks are unlikely to affect rates of recruitment and 
survival for the stocks.
    Altogether, while this population of sperm whales is stable and the 
status of the Kogia species stocks are unknown, most members of the 
stocks will likely be taken by Level B harassment at a low to 
occasionally moderate level over several days a year, and some smaller 
portion of the stocks are expected to be taken on a relatively moderate 
to high number of days (up to 18 or 24) across the year, some of which 
could be sequential days. No mortality is anticipated or authorized for 
any of

[[Page 41881]]

these stocks. Thirty-eight individuals from the two Kogia stocks are 
expected to be taken by PTS annually of likely low severity, with this 
unlikely to impact behaviors, opportunities, or detection capabilities 
to a degree that would interfere with reproductive success or survival 
of those individuals. Though the majority of impacts are expected to be 
of a lower to sometimes moderate severity, the larger number of takes 
for a subset of individuals makes it more likely that a small number of 
individuals could be interrupted during foraging in a manner and amount 
such that impacts to the energy budgets of females (from either losing 
feeding opportunities or expending considerable energy to find 
alternative feeding options) could cause them to forego reproduction 
for a year. Energetic impacts to males are generally meaningless to 
population rates unless they cause death, and it takes extreme energy 
deficits beyond what would ever be likely to result from these 
activities to cause the death of an adult marine mammal. As discussed 
in the 2018 HSTT final rule, however, foregone reproduction (especially 
for one year, which is the maximum predicted because the small number 
anticipated in any one year makes the probability that any individual 
would be impacted in this way twice in seven years very low) has far 
less of an impact on population rates than mortality and a small number 
of instances of foregone reproduction is not expected to adversely 
affect these stocks through effects on annual rates of recruitment or 
survival. We also note that residual PBR is 19.2 for pygmy sperm whales 
and 1.6 for sperm whales. Both the abundance and PBR are unknown for 
dwarf sperm whales, however, we know that take of this stock is likely 
significantly lower in magnitude and severity (i.e., lower number of 
total takes and repeated takes of any individual) than pygmy sperm 
whales. For these reasons, in consideration of all of the effects of 
the Navy's activities combined, we have determined that the authorized 
take will have a negligible impact on the CA/OR/WA stocks of sperm 
whales and pygmy and dwarf sperm whales.
Sperm Whale (Hawaii Stock)
    The SAR does not identify a trend for this stock and the species is 
listed as endangered under the ESA. No Level A harassment by PTS or 
tissue damage is expected or authorized. NMFS authorizes one mortality 
over the seven years covered by this rule, which is 0.14 mortalities 
annually. The addition of this 0.14 annual mortality still leaves the 
total human-caused mortality well under the insignificance threshold 
for residual PBR. In addition, even with the additional two years of 
activities under this rule, no additional M/SI is estimated for this 
stock, leading to a slight decrease (from 0.2 to 0.14 annually) in 
annual mortality from the 2018 HSTT final rule.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated instances of take 
compared to the abundance, both throughout the HSTT Study Area and 
within the U.S. EEZ, respectively, is 151 and 147 percent. This 
information and the sperm whale stock range suggest that likely only a 
smaller portion of the stock will be impacted, over one to a few days 
per year, with little likelihood of take across sequential days. 
Regarding the severity of those individual Level B harassment takes by 
behavioral disruption, 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 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 sperm whale communication or other important low-
frequency cues, and the associated lost opportunities and capabilities 
are not at a level that will impact reproduction or survival.
    Altogether, while the status of this population is unknown, a 
relatively small portion of this stock is anticipated to be impacted 
and any individuals are likely to be disturbed at a low-moderate level, 
with the taken individuals likely exposed between one and a few days, 
with little chance that any are taken across sequential days. No Level 
A harassment by PTS or tissue damage is expected or authorized. This 
low magnitude and severity of harassment effects is not expected to 
result in impacts on individual reproduction or survival, nor are these 
harassment takes combined with the one authorized mortality expected to 
adversely affect the stock 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 the Hawaii 
stock of sperm whales.
Pygmy and Dwarf Sperm Whales (Hawaii Stocks)
    The SAR does not identify a trend for these stocks and the species 
are not listed under the ESA. No mortality or Level A harassment by 
tissue damage is anticipated or authorized. Regarding the magnitude of 
Level B harassment takes (TTS and behavioral disruption), the number of 
estimated instances of take compared to the abundance, both throughout 
the HSTT Study Area and within the U.S. EEZ, respectively, is 244-249 
and 235-240 percent. This information and the pygmy and dwarf sperm 
whale stock ranges (at least throughout the U.S. EEZ around the entire 
Hawaiian Islands) suggest that likely a fair portion of each stock is 
not impacted, but that a subset of individuals may be taken over one to 
perhaps five days per year, with little likelihood of take across 
sequential days. Regarding the severity of those individual Level B 
harassment takes by behavioral disruption, 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). Additionally, as discussed earlier, within the Hawaii Island 
Mitigation Area, explosives are not used and the use of MF1 and MF4 
active sonar is limited, greatly reducing the severity of impacts 
within the small resident population BIA for dwarf sperm whales, which 
is entirely contained within this mitigation area.
    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 pygmy or dwarf sperm whale communication 
or other important low-frequency cues--and the associated lost 
opportunities and capabilities are not at a level that will impact 
reproduction or survival. For these same reasons (low level and 
frequency band), while a small permanent loss of hearing sensitivity 
may include some degree of energetic costs for compensating or may mean 
some small loss of opportunities or detection capabilities, at the 
expected scale, estimated Level A harassment takes by PTS for these 
stocks of dwarf and pygmy sperm whales will be unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
will interfere with reproductive success or survival of any 
individuals, even if it were to be experienced by an animal that also 
experiences one or more instances of Level B harassment by behavioral 
disruption. Thus the 64 and 29 total Level A harassment takes by PTS 
for dwarf and pygmy sperm whales,

[[Page 41882]]

respectively, will be unlikely to affect rates of recruitment and 
survival for these stocks.
    Altogether, while the status of these populations is unknown, only 
a portion of these stocks are likely to be impacted and any individuals 
are likely to be disturbed at a low-moderate level, with the taken 
individuals likely exposed between one and five days, with little 
chance that any are taken across sequential days. No mortality is 
anticipated or authorized. This low magnitude and severity of Level B 
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 for these stocks. Sixty-four dwarf sperm whales 
and 29 pygmy sperm whales are estimated to be taken by PTS annually of 
likely low severity, with this unlikely to impact behaviors, 
opportunities, or detection capabilities to a degree that would 
interfere with reproductive success or survival of those individuals, 
let alone have effects 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 expected and 
authorized take will have a negligible impact on the Hawaii stocks of 
pygmy and dwarf sperm whales.

Beaked Whales

    In Tables 22 and 23 below for beaked whales, we indicate the total 
annual mortality, Level A and Level B harassment, and a number 
indicating the instances of total take as a percentage of abundance. 
Tables 22 and 23 are unchanged from Tables 75 and 76 in the 2018 HSTT 
final rule. For additional information and analysis supporting the 
negligible-impact analysis, see the Odontocetes discussion as well as 
the Beaked Whales discussion in the Group and Species-Specific Analyses 
section of the 2018 HSTT final rule, all of which remains applicable to 
this final rule unless specifically noted.

    Table 22--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Beaked Whales in the HRC portion of the HSTT Study Area and Number Indicating the Instances of Total Take as a Percentage of Stock
                                                                                                                Abundance
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Instances of indicated types of incidental take (not all takes          Total takes                Abundance           Instances of total take as
                                                                                       represent separate individuals, especially for disturbance)   ----------------------------------------------------      percent of abundance
                                                                                   ------------------------------------------------------------------                                                    -------------------------------
                                                                                        Level B harassment        Level A harassment                                             Total Navy   Within EEZ   Total take as
                    Species                                    Stock               -----------------------------------------------------              Total takes     Takes      abundance       Navy      percentage of    EEZ take as
                                                                                                   TTS  (may                              Mortality     (entire      (within     inside and   abundance     total Navy     percentage of
                                                                                     Behavioral  also include      PTS         Tissue                 study area)   NAVY EEZ)     outside       (HRC)        abundance    EEZ  abundance
                                                                                    disturbance  disturbance)                  damage                                            EEZ (HRC)                     (HRC)           (HRC)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Blainville's beaked whale......................  Hawaii...........................        5,369            16            0            0            0        5,385        4,140          989          768             545             539
Cuvier's beaked whale..........................  Hawaii...........................        1,792             4            0            0            0        1,796        1,377          345          268             521             514
Longman's beaked whale.........................  Hawaii...........................       19,152            81            0            0            0       19,233       14,585        3,568        2,770             539             527
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the HI take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule), both
  in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area used to generate the abundance estimates in the SARs, and the abundance predicted by the same
  underlying density estimates is the preferred abundance to use, there is no need to separately compare the take to the SARs abundance estimate.
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.


 Table 23--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Beaked Whales in the SOCAL Portion of the HSTT Study Area and Number Indicating the Instances of
                                                                          Total Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Instances of indicated types of incidental take (not all takes   Total takes          Abundance           Instances of total take as
                                                            represent separate individuals, especially for disturbance)   ---------------------------------------      percent of abundance
                                                        ------------------------------------------------------------------                                       -------------------------------
                                                             Level B harassment        Level A harassment
             Species                       Stock        -----------------------------------------------------              Total takes      Navy                   Total take as   Total take as
                                                                        TTS (may                                             (entire     abundance    NMFS SARS    percentage of   percentage of
                                                          Behavioral  also include                  Tissue     Mortality   study area)   in action    abundance     total Navy       total SAR
                                                         disturbance                    PTS         damage                                  area                   abundance in      abundance
                                                                      disturbance)                                                                                  action area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Baird's beaked whale.............  CA/OR/WA............        2,030            14            0            0            0        2,044           74        2,697           2,762              76
Cuvier's beaked whale............  CA/OR/WA............       11,373           127            1            0            0       11,501          520        3,274           2,212             351
Mesoplodon species...............  CA/OR/WA............        6,125            68            1            0            0        6,194           89        3,044           6,960             203
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
  and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
  predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.

    Below we compile and summarize the information that supports our 
determination that the Navy's activities will not adversely affect any 
species or stocks through effects on annual rates of recruitment or 
survival for any of the affected stocks addressed in this section.
Blainville's, Cuvier's, and Longman's Beaked Whales (Hawaii Stocks)
    The SAR does not identify a trend for these stocks and the species 
are not listed under the ESA. No mortality or Level A harassment are 
expected or authorized for any of these three stocks. Regarding the 
magnitude of Level B harassment takes (TTS and behavioral disruption), 
the number of estimated instances of take compared to the abundance, 
both throughout the HSTT Study Area and within the U.S. EEZ, 
respectively, is 521-545 and 514-539 percent. This information and the 
stock ranges (at least of the small, resident Island associated stocks 
around Hawaii) suggest that likely a fair portion of the stocks (but 
not all) will be impacted,

[[Page 41883]]

over one to perhaps eleven days per year, with little likelihood of 
much take across sequential days. Regarding the severity of those 
individual Level B harassment takes by behavioral disruption, 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 or two (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. Additionally, as noted earlier, within the 
Hawaii Island mitigation area (which entirely contains the BIAs for 
Cuvier's and Blainville's beaked whales), explosives are not used and 
the use of MF1 and MF4 active sonar is limited, greatly reducing the 
severity of impacts to these two small resident populations.
    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 beaked whale communication or other 
important low-frequency cues, and the associated lost opportunities and 
capabilities are not at a level that will impact reproduction or 
survival.
    Altogether, the population trend for the three stocks is unknown, a 
fair portion of these stocks are anticipated to be impacted, and any 
individuals are likely to be disturbed at a moderate level, with the 
taken individuals likely exposed between one and eleven days, with 
little chance that individuals are taken across sequential days. No 
mortality or Level A harassment are expected or authorized for any of 
these three stocks. This low, to occasionally moderate, magnitude and 
severity of harassment effects is not expected to result in impacts on 
individual reproduction or survival, much less have impacts on annual 
rates of recruitment or survival for these stocks. 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 the Hawaii stocks of beaked whales.
Baird's and Cuvier's Beaked Whales and Mesoplodon Species (all CA/OR/WA 
Stocks)
    These species are not listed under the ESA and their populations 
have been identified as ``stable,'' ``decreasing,'' and ``increasing,'' 
respectively. No mortality is expected or authorized for any of these 
stocks and only two takes by Level A harassment (PTS) are expected and 
authorized (one each for Cuvier's beaked whale and the Mesoplodon 
species). No Level A harassment by tissue damage is anticipated or 
authorized.
    No methods are available to distinguish between the six Mesoplodon 
beaked whale CA/OR/WA stocks (Blainville's beaked whale (M. 
densirostris), Perrin's beaked whale (M. perrini), Lesser beaked whale 
(M. peruvianus), Stejneger's beaked whale (M. stejnegeri), Gingko-
toothed beaked whale (M. gingkodens), and Hubbs' beaked whale (M. 
carlhubbsi)) when observed during at-sea surveys (Carretta et al., 
2018). Bycatch and stranding records from the region indicate that the 
Hubbs' beaked whale is most commonly encountered (Carretta et al., 
2008, Moore and Barlow, 2013). As indicated in the SAR, no species-
specific abundance estimates are available, the abundance estimate 
includes all CA/OR/WA Mesoplodon species, and the six species are 
managed as one unit. Due to the lack of species-specific abundance 
estimates it is not possible to predict the take of individual species 
and take estimates are also identified as Mesoplodon species.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance for these stocks is 2,762, 2,212, and 6,960 
percent (measured against Navy-estimated abundance) and 76, 351, and 
203 percent (measured against the SAR) for Baird's beaked whales, 
Cuvier's beaked whales, and Mesoplodon species, respectively. Given the 
ranges of these stocks, this information suggests that some smaller 
portion of the individuals of these stocks will be taken, and that some 
subset of individuals within the stock will be taken repeatedly within 
the year (perhaps up to 20-25 days, and potentially more for 
Cuvier's)--potentially over a fair number of sequential days, 
especially where individuals spend extensive time in the SOCAL Range. 
Note that we predict fewer days of repeated exposure for these stocks 
than their percentages might have suggested because of the number of 
overall takes--i.e., using the higher percentage would suggest that an 
unlikely portion of the takes are taken up by a small portion of the 
stock incurring a very large number of repeat takes, with little room 
for take resulting from few or moderate numbers of repeats, which is 
unlikely.
    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 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 or 
two (i.e., of a moderate level). While interrupted feeding bouts are a 
known response and concern for odontocetes, we also know that there are 
often viable alternative habitat options in the relative vicinity. 
However, as noted, some of these takes could occur on a fair number of 
sequential days for these stocks.
    The severity of TTS takes are expected to be low-level, of short 
duration, and mostly not in a frequency band that would be expected to 
interfere significantly with conspecific communication, echolocation, 
or other important low-frequency cues. Therefore, the associated lost 
opportunities and capabilities are not expected to impact reproduction 
or survival. For similar reasons (as described in the 2018 HSTT final 
rule) the single Level A harassment take each by PTS for the Cuvier's 
beaked whale stock and the Mesoplodon species is unlikely to have any 
effects on the reproduction or survival of those individuals, even if 
it were to be experienced by an animal that also experiences one or 
more Level B harassment takes by behavioral disruption.
    Altogether, a portion of these stocks will likely be taken (at a 
moderate or sometimes low level) over several days a year, and some 
smaller portion of the stock is expected to be taken on a relatively 
moderate to high number of days across the year, some of which could be 
sequential days. No mortality is expected or authorized for any of 
these stocks. Two individuals (one each for Cuvier's beaked whale and 
the Mesoplodon species) are expected to be taken by PTS annually 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 one Level A harassment take by 
PTS would be unlikely to impact behaviors, opportunities, or detection 
capabilities to a degree that would interfere with reproductive success 
or survival of that individual. Though the majority of impacts are 
expected to be of a moderate severity,

[[Page 41884]]

the repeated takes over a potentially fair number of sequential days 
for some individuals makes it more likely that a small number of 
individuals could be interrupted during foraging in a manner and amount 
such that impacts to the energy budgets of females (from either losing 
feeding opportunities or expending considerable energy to find 
alternative feeding options) could cause them to forego reproduction 
for a year. Energetic impacts to males are generally meaningless to 
population rates unless they cause death, and it takes extreme energy 
deficits beyond what would ever be likely to result from these 
activities to cause the death of an adult marine mammal. As noted 
previously, however, foregone reproduction (especially for one year, 
which is the maximum predicted because the small number anticipated in 
any one year makes the probability that any individual would be 
impacted in this way twice in seven years very low) has far less of an 
impact on population rates than mortality and a small number of 
instances of foregone reproduction is not expected to adversely affect 
these stocks through effects on annual rates of recruitment or 
survival, especially given the residual PBR of these three beaked whale 
stocks (16, 21, and 20, respectively).
    Further, Navy activities have been conducted in SOCAL for many 
years at similar levels and the SAR considers Mesoplodon species as 
increasing and Baird's beaked whales as stable. While NMFS' SAR 
indicates that Cuvier's beaked whales on the U.S. West Coast are 
declining based on a Bayesian trend analysis of NMFS' survey data 
collected from 1991 through 2014, results from passive acoustic 
monitoring and other research have estimated regional Cuvier's beaked 
whale densities that were higher than indicated by NMFS' broad-scale 
visual surveys for the U.S. West Coast (Debich et al., 2015a; Debich et 
al., 2015b; Falcone and Schorr, 2012, 2014; Hildebrand et al., 2009; 
Moretti, 2016; [Scaron]irovi[cacute] et al., 2016; Smultea and 
Jefferson, 2014). Research also indicates higher than expected 
residency in the Navy's instrumented Southern California Anti-Submarine 
Warfare Range in particular (Falcone and Schorr, 2012) and photo 
identification studies in the SOCAL have identified approximately 100 
individual 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). The documented residency by 
many Cuvier's beaked whales over multiple years suggests that a stable 
population may exist in that small portion of the stock's overall range 
(e.g., Falcone et al., 2009; Falcone and Schorr, 2014; Schorr et al., 
2017).
    For these reasons, in consideration of all of the effects of the 
Navy's activities combined, we have determined that the authorized take 
will have a negligible impact on the CA/OR/WA stocks of Baird's and 
Cuvier's beaked whales, as well as all six species included within the 
Mesoplodon CA/OR/WA stocks.

Small Whales and Dolphins

    In Tables 24 and 25 below for dolphins and small whales, we 
indicate the total annual mortality, Level A and Level B harassment, 
and a number indicating the instances of total take as a percentage of 
abundance. Tables 24 and 25 are updated from Tables 77 and 78 in the 
2018 HSTT final rule as appropriate with the 2018 final SARs and with 
updated information on mortality, as discussed above. For additional 
information and analysis supporting the negligible-impact analysis, see 
the Odontocetes discussion as well as the Small Whales and Dolphins 
discussion in the Group and Species-Specific Analyses section of the 
2018 HSTT final rule, all of which remains applicable to this final 
rule unless specifically noted.

 Table 24--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Dolphins and Small Whales in the HRC Portion of the HSTT Study Area and Number Indicating the Instances of Total Take as a Percentage of
                                                                                                             Stock Abundance
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Instances of indicated types of incidental take  (not all takes  Total takes                       Abundance            Instance of total take as
                                                                                       represent separate individuals, especially for disturbance)   -------------             --------------------------      percent of abundance
                                                                                   ------------------------------------------------------------------                                                    -------------------------------
                                                                                        Level B harassment        Level A harassment                                  Takes      Total Navy
                    Species                                    Stock               -----------------------------------------------------              Total takes    (within     abundance    Within EEZ   Total take as    EEZ take as
                                                                                                   TTS  (may                                             (entire    Navy EEZ)    inside and      Navy      percentage of   percentage of
                                                                                     Behavioral      also                      Tissue     Mortality   study area)                outside of   abundance     total Navy       Navy EEZ
                                                                                    disturbance     include        PTS         damage                                            EEZ  (HRC)     (HRC)        abundance       abundance
                                                                                                 disturbance)                                                                                                  (HRC)           (HRC)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin.............................  Hawaii Pelagic...................        3,196           132            0            0            0        3,328        2,481        1,528        1,442             218             172
Bottlenose dolphin.............................  Kauai & Niihau...................          534            31            0            0            0          565          264          184          184             307             143
Bottlenose dolphin.............................  Oahu.............................        8,600            61            1            0            0        8,662        8,376          743          743           1,169           1,130
Bottlenose dolphin.............................  4-Island.........................          349            10            0            0            0          359          316          189          189             190             167
Bottlenose dolphin.............................  Hawaii...........................           74             6            0            0            0           80           42          131          131              61              32
False killer whale.............................  Hawaii Pelagic...................          999            42            0            0            0        1,041          766          645          507             161             151
False killer whale.............................  Main Hawaiian Islands Insular....          572            17            0            0            0          589          476          147          147             400             324
False killer whale.............................  Northwestern Hawaiian Islands....          365            16            0            0            0          381          280          215          169             177             166
Fraser's dolphin...............................  Hawaii...........................       39,784         1,289            2            0            0       41,075       31,120        5,408       18,763             760             166
Killer whale...................................  Hawaii...........................          118             6            0            0            0          124           93           69           54             180             172
Melon-headed whale.............................  Hawaii Islands...................        3,261           231            0            0            0        3,492        2,557        1,782        1,782             196             143
Melon-headed whale.............................  Kohala Resident..................          341             9            0            0            0          350          182          447          447              78              41
Pantropical spotted dolphin....................  Hawaii Island....................        3,767           227            0            0            0        3,994        2,576        2,405        2,405             166             107

[[Page 41885]]

 
Pantropical spotted dolphin....................  Hawaii Pelagic...................        9,973           476            0            0            0       10,449        7,600        5,462        4,637             191             164
Pantropical spotted dolphin....................  Oahu.............................        4,284            45            0            0            0        4,329        4,194          372          372           1,164           1,127
Pantropical spotted dolphin....................  4-Island.........................          701            17            0            0            0          718          634          657          657             109              96
Pygmy killer whale.............................  Hawaii...........................        8,122           402            0            0            0        8,524        6,538        4,928        3,931             173             166
Pygmy killer whale.............................  Tropical.........................          710            50            0            0            0          760          490          159           23             478           2,130
Risso's dolphin................................  Hawaii...........................        8,950           448            0            0            0        9,398        7,318        1,210        4,199             777             174
Rough-toothed dolphin..........................  Hawaii...........................        6,112           373            0            0            0        6,485        4,859        3,054        2,808             212             173
Short-finned pilot whale.......................  Hawaii...........................       12,499           433            0            0            0       12,932        9,946        6,433        5,784             201             172
Spinner dolphin................................  Hawaii Island....................          279            12            0            0            0          291           89          629          629              46              14
Spinner dolphin................................  Hawaii Pelagic...................        4,332           202            0            0            0        4,534        3,491        2,885        2,229             157             157
Spinner dolphin................................  Kauai & Niihau...................        1,683            63            0            0            0        1,746          812          604          604             289             134
Spinner dolphin................................  Oahu & 4-Island..................        1,790            34            1            0            0        1,825        1,708          354          354             516             482
Striped dolphin................................  Hawaii...........................        7,379           405            0            0            0        7,784        6,034        4,779        3,646             163             165
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the HI take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule), both
  in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area used to generate the abundance estimates in the SARs, and the abundance predicted by the same
  underlying density estimates is the preferred abundance to use, there is no need to separately compare the take to the SARs abundance estimate.
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.


  Table 25--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Dolphins and Small Whales in the SOCAL Portion of the HSTT Study Area and Number Indicating the
                                                                   Instances of Total Take as a Percentage of Stock Abundance.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Instances of indicated types of incidental take (not all takes   Total takes          Abundance            Instance of total take as
                                                            represent separate individuals, especially for disturbance)   ---------------------------------------      percent of abundance
                                                        ------------------------------------------------------------------                                       -------------------------------
                                                             Level B harassment        Level A harassment                                   Navy                   Total take as
             Species                       Stock        -----------------------------------------------------              Total takes   abundance    NMFS SARS    percentage of   Total take as
                                                                        TTS (may                               Mortality     (entire     in action    abundance     total Navy     percentage of
                                                          Behavioral  also include      PTS         Tissue                 study area)      area                   abundance in      total SAR
                                                         disturbance  disturbance)                  damage                                (SOCAL)                   action area      abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin...............  California Coastal..        1,771            38            0            0            0        1,809          238          453             760             399
Bottlenose dolphin...............  CA/OR/WA Offshore...       51,727         3,695            3            0            0       55,425        5,946        1,924             932           2,881
Killer whale.....................  Eastern North                  96            11            0            0            0          107            4          300           2,675              36
                                    Pacific (ENP)
                                    Offshore.
Killer whale.....................  ENP Transient/West            179            20            0            0            0          199           30          243             663              82
                                    Coast Transient.
Long-beaked common dolphin.......  California..........      233,485        13,787           18            2            0      247,292       10,258      101,305           2,411             244
Northern right whale dolphin.....  CA/OR/WA............       90,052         8,047           10            1            0       98,110        7,705       26,556           1,273             369
Pacific white-sided dolphin......  CA/OR/WA............       69,245         6,093            5            0            0       75,343        6,626       26,814           1,137             281
Risso's dolphin..................  CA/OR/WA............      116,143        10,118            9            0            0      126,270        7,784        6,336           1,622           1,993
Short-beaked common dolphin......  CA/OR/WA............    1,374,048       118,525           79           10         1.14    1,492,664      261,438      969,861             571             154
Short-finned pilot whale.........  CA/OR/WA............        1,789           124            1            0            0        1,914          208          836             920             229
Striped dolphin..................  CA/OR/WA............      163,640        11,614            3            0            0      175,257       39,862       29,211             440             600
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
  and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
  predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.
For mortality takes there is an annual average of 1.14 short-beaked common dolphins (i.e., where eight takes could potentially occur divided by seven years to get the annual number of
  mortalities/serious injuries).
Mortality for the CA/OR/WA stock of short-beaked common dolphins was unintentionally presented incorrectly as 2 in Table 78 of the 2018 HSTT final rule. The correct value (updated for seven
  years of activity) is provided here. This transcription error does not affect the analysis or conclusions in the 2018 HSTT final rule, as the correct value was used in the analysis presented
  in the Analysis and Negligible Impact Determination section.


[[Page 41886]]

    Below we compile and summarize the information that supports our 
determination that the Navy's activities will not adversely affect any 
species or stocks through effects on annual rates of recruitment or 
survival for any of the affected stocks addressed in this section.
Long-Beaked Common Dolphin (California Stock), Northern Right Whale 
Dolphin (CA/OR/WA Stock), and Short-Beaked Common Dolphin (CA/OR/WA 
Stock)
    None of these species is listed under the ESA and their stock 
statuses are considered ``increasing,'' ``unknown,'' and ``stable,'' 
respectively. Eight mortalities or serious injuries of short-beaked 
common dolphins are estimated and authorized over the seven-year rule, 
or 1.14 M/SI annually. The addition of this 1.14 annual mortality still 
leaves the total human-caused mortality well under the insignificance 
threshold for residual PBR. The three stocks are expected to accrue 2, 
1, and 10 Level A harassment takes from tissue damage resulting from 
exposure to explosives, respectively. As described in detail in the 
2018 HSTT final rule, the impacts of a Level A harassment take by 
tissue damage could range in impact from minor to something just less 
than M/SI that could seriously impact fitness. However, given the 
Navy's procedural mitigation, exposure at the closer to the source and 
more severe end of the spectrum is less likely and we cautiously assume 
some moderate impact for these takes that could lower the affected 
individual's fitness within the year such that a female (assuming a 50 
percent chance of it being a female) might forego reproduction for one 
year. As noted previously, foregone reproduction has less of an impact 
on population rates than death (especially for only one year in seven, 
which is the maximum predicted because the small number anticipated in 
any one year makes the probability that any individual would be 
impacted in this way twice in seven years very low), and 1 to 10 
instances is not expected to impact annual rates of recruitment or 
survival for these stocks.
    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 2,411, 1,273, and 571 percent (measured 
against the Navy-estimated abundance) and 244, 369, and 154 percent 
(measured against the SAR abundance) for long-beaked common dolphins, 
northern right whale dolphins, and short-beaked common dolphins, 
respectively. Given the range of these stocks, this information 
suggests that likely some portion (but not all or even the majority) of 
the individuals in the northern right whale dolphin and short-beaked 
common dolphin stocks are likely impacted, while it is entirely 
possible that most or all of the range-limited long-beaked common 
dolphin is taken. All three stocks likely will experience some repeat 
Level B harassment exposure (perhaps up to 48, 25, and 11 days within a 
year for long-beaked common dolphins, northern right whale dolphins, 
and short-beaked common dolphins, respectively) of some subset of 
individuals that spend extended time within the SOCAL range complex. 
Regarding the severity of those individual Level B harassment takes by 
behavioral disruption, 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 interrupted feeding bouts are a known response and concern for 
odontocetes, we also know that there are often viable alternative 
habitat options in the relative vicinity. However, some of these takes 
could occur on a fair number of sequential days for long-beaked common 
dolphins or northern right whale dolphins, or even some number of 
short-beaked common dolphins, given the higher number of total takes 
(i.e., the probability that some number of individuals get taken on a 
higher number of sequential days is higher, because the total take 
number is relatively high, even though the percentage is not that 
high).
    The severity of TTS takes is expected to be low-level, of short 
duration, and mostly not in a frequency band that would be expected to 
interfere significantly with conspecific communication, echolocation, 
or other important low-frequency cues, and the associated lost 
opportunities and capabilities is not expected to impact reproduction 
or survival. For these same reasons (low level and frequency band), 
while a small permanent loss of hearing sensitivity may include some 
degree of energetic costs for compensating or may mean some small loss 
of opportunities or detection capabilities, as discussed in the 2018 
HSTT final rule, the 18, 10, and 79 Level A harassment takes by PTS for 
long-beaked common dolphins, northern right whale dolphins, and short-
beaked common dolphins, respectively are unlikely to impact behaviors, 
opportunities, or detection capabilities to a degree that would 
interfere with reproductive success or survival of any individuals, 
even if it were to be experienced by an animal that also experiences 
one or more Level B harassment takes by behavioral disruption.
    Altogether these stock statuses are considered ``increasing,'' 
``unknown,'' and ``stable,'' respectively. Eight mortalities of short-
beaked common dolphins are authorized (1.14 takes annually), and all 
three stocks may experience a very small number of Level A harassment 
takes (relative to the stock abundance and PBR) by tissue damage or 
PTS. The 18, 10, and 79 takes by PTS annually of likely low severity 
are unlikely to impact behaviors, opportunities, or detection 
capabilities to a degree that would interfere with reproductive success 
or survival of those individuals, let alone have effects on annual 
rates of recruitment or survival. Nonetheless, a moderate to large 
portion of all three stocks will likely be taken (at a low to 
occasionally moderate level) over several days a year, and some smaller 
portion of these stocks is expected to be taken on a relatively 
moderate to high number of days across the year, some of which could be 
sequential days. Though the majority of impacts are expected to be of a 
lower to sometimes moderate severity, the larger number of takes (in 
total and for certain individuals) makes it more likely 
(probabilistically) that a small number of individuals could be 
interrupted during foraging in a manner and amount such that impacts to 
the energy budgets of females (from either losing feeding opportunities 
or expending considerable energy to find alternative feeding options) 
could cause them to forego reproduction for a year. Energetic impacts 
to males are generally meaningless to population rates unless they 
cause death, and it takes extreme energy deficits beyond what would 
ever be likely to result from these activities to cause the death of an 
adult marine mammal. As noted previously, however, foregone 
reproduction (especially for only one year out of seven, which is the 
maximum predicted because the small number anticipated in any one year 
makes the probability that any individual would be impacted in this way 
twice in seven years very low) has far less of an impact on population 
rates than mortality and a small number of instances of foregone 
reproduction (including in combination with that which might result 
from the small number of Level A harassment takes from tissue damage) 
along with the estimated eight mortalities or serious injuries for 
short-beaked common dolphins is not expected to adversely

[[Page 41887]]

affect any of the stocks through effects on annual rates of recruitment 
or survival, especially given the very high residual PBRs of these 
stocks (621, 175, and 8,353, respectively). For these reasons, in 
consideration of all of the effects of the Navy's activities combined 
(mortality, Level A harassment, and Level B harassment), we have 
determined that the authorized take will have a negligible impact on 
these three stocks of dolphins.
All Other SOCAL Dolphin Stocks (Except Long-Beaked Common Dolphin, 
Northern Right Whale Dolphin, and Short-Beaked Common Dolphin)
    None of these species is listed under the ESA and their stock 
statuses are considered ``unknown,'' except for the bottlenose dolphin 
(California coastal stock) and killer whale (Eastern North Pacific 
stock), which are considered ``stable.'' No mortality or Level A 
harassment via tissue damage from exposure to explosives is expected or 
authorized for these stocks.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the Navy-estimated 
abundance and the SAR) is from 440 to 2,675 percent and 36 to 2,881 
percent, respectively. Given the range of these stocks (along the 
entire U.S. West Coast, or even beyond, with some also extending 
seaward of the HSTT Study Area boundaries), this information suggests 
that some portion (but not all or even the majority) of the individuals 
of any of these stocks will be taken, with the exception that most or 
all of the individuals of the more range-limited California coastal 
stock of bottlenose dolphin may be taken. It is also likely that some 
subset of individuals within most of these stocks will be taken 
repeatedly within the year (perhaps up to 10-15 days within a year), 
but for no more than several potentially sequential days, although the 
CA/OR/WA stocks of bottlenose dolphins, Pacific white-sided dolphins, 
and Risso's dolphins may include individuals that are taken repeatedly 
within the year over a higher number of days (up to 57, 22, and 40 
days, respectively) and potentially over a fair number of sequential 
days, especially where individuals spend extensive time in the SOCAL 
range complex. Note that though percentages are high for the Eastern 
North Pacific stock of killer whales and short-finned pilot whales, 
given the low overall number of takes, it is highly unlikely that any 
individuals would be taken across the number of days their percentages 
suggest.
    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, or sometimes moderate level, less likely to evoke a severe 
response). While interrupted feeding bouts are a known response and 
concern for odontocetes, we also know that there are often viable 
alternative habitat options in the relative vicinity. However, as 
noted, some of these takes could occur on a fair number of sequential 
days for the three stocks listed earlier.
    The severity of TTS takes is expected to be low-level, of short 
duration, and mostly not in a frequency band that would be expected to 
interfere significantly with conspecific communication, echolocation, 
or other important low-frequency cues. For these same reasons (low 
level and frequency band), while 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, it is unlikely to impact behaviors, opportunities, or 
detection capabilities to a degree that would interfere with 
reproductive success or survival of any individuals, even if it were to 
be experienced by an animal that also experiences one or more Level B 
harassment takes by behavioral disruption.
    Altogether, the status of these stocks is either unknown or stable. 
The small number of annual estimated takes by PTS of likely low 
severity for several stocks are unlikely to impact behaviors, 
opportunities, or detection capabilities to a degree that would 
interfere with reproductive success or survival of those individuals, 
let alone have effects on annual rates of recruitment or survival. A 
portion of all of these stocks will likely be taken (at a low to 
occasionally moderate level) over several days a year, and some smaller 
portion of the CA/OR/WA stocks of bottlenose dolphins, Pacific white-
sided dolphins, and Risso's dolphins, specifically, are expected to be 
taken on a relatively moderate to high number of days across the year, 
some of which could be sequential days. Though the majority of impacts 
are expected to be of a lower to sometimes moderate severity, the 
larger number of takes (in total and for certain individuals) for the 
CA/OR/WA stocks of bottlenose dolphins, Pacific white-sided dolphins, 
and Risso's dolphins makes it more likely (probabilistically) that a 
small number of individuals could be interrupted during foraging in a 
manner and amount such that impacts to the energy budgets of females 
(from either losing feeding opportunities or expending considerable 
energy to find alternative feeding options) could cause them to forego 
reproduction for a year. Energetic impacts to males are generally 
meaningless to population rates unless they cause death, and it takes 
extreme energy deficits beyond what would ever be likely to result from 
these activities to cause the death of an adult marine mammal. As noted 
previously, however, foregone reproduction (especially for only one 
year in seven, which is the maximum predicted because the small number 
anticipated in any one year makes the probability that any individual 
would be impacted in this way twice in seven years very low) has far 
less of an impact on population rates than mortality and a small number 
of instances of foregone reproduction is not expected to adversely 
affect the stocks through effects on annual rates of recruitment or 
survival, especially given the residual PBRs of the CA/OR/WA stocks of 
bottlenose dolphins, Pacific white-sided dolphins, and Risso's dolphins 
(9.4, 183, and 84, respectively). For these reasons, in consideration 
of all of the effects of the Navy's activities combined, we have 
determined that the authorized take will have a negligible impact on 
these stocks of dolphins.
All HRC Dolphin Stocks
    With the exception of the Main Hawaiian Island DPS of false killer 
whales (listed as endangered under the ESA, with the MMPA stock 
identified as ``decreasing''), none of these species are listed under 
the ESA and their stock statuses are considered ``unknown.'' No 
mortality or Level A harassment via tissue damage from exposure to 
explosives is expected or authorized for these stocks.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the Navy-estimated 
abundance and the SAR) is from 46 to 1,169 percent and 41 to 2,130 
percent, respectively. Given the ranges of these stocks (many of them 
are small, resident, island-associated stocks), this information 
suggests that a fairly large portion of the individuals of many of 
these stocks will be taken, but that most individuals will only be 
impacted across a smaller to moderate number of days within the year 
(1-15), and with no more than several potentially sequential days, 
although

[[Page 41888]]

two stocks (the Oahu stocks of bottlenose dolphin and pantropical 
spotted dolphin) have a slightly higher percentage, suggesting they 
could be taken up to 23 days within a year, with perhaps a few more of 
those days being sequential. We note that although the percentage is 
higher for the tropical stock of pygmy killer whale within the U.S. EEZ 
(2,130), given (1) the low overall number of takes (760) and (2) the 
fact that the small within-U.S. EEZ abundance is not a static set of 
individuals, but rather individuals moving in and out of the U.S. EEZ 
making it more appropriate to use the percentage comparison for the 
total takes versus total abundance--it is highly unlikely that any 
individuals would be taken across the number of days that the within-
U.S. EEZ percentage suggests which is 42.
    Regarding the severity of those individual Level B harassment takes 
by behavioral disruption, 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, or sometimes 
moderate level, less likely to evoke a severe response). While 
interrupted feeding bouts are a known response and concern for 
odontocetes, we also know that there are often viable alternative 
habitat options in the relative vicinity. However, as noted, some of 
these takes could occur on a fair number of sequential days for the 
Oahu stocks of bottlenose dolphin and pantropical spotted dolphins.
    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 significantly with conspecific communication, 
echolocation, or other important low-frequency cues. For these same 
reasons (low level and frequency band), while 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, they will be unlikely to impact behaviors, 
opportunities, or detection capabilities to a degree that would 
interfere with reproductive success or survival of the one or two 
individuals from the three affected stocks, even if accrued to 
individuals that are also taken by behavioral harassment at the same 
time.
    Altogether, the status these stocks is unknown (with the exception 
of the Main Hawaiian Islands Insular stock identified as 
``decreasing'') and most of these stocks (all but the Oahu stocks of 
bottlenose dolphin and pantropical spotted dolphins) will likely be 
taken at a low to occasionally moderate level over several days a year, 
with some smaller portion of the stock potentially taken on a more 
moderate number of days across the year (perhaps up to 15 days for 
Fraser's dolphin, though others notably less), some of which could be 
across a few sequential days, which is not expected to affect the 
reproductive success or survival of individuals. For the Oahu stocks of 
bottlenose dolphin and pantropical spotted dolphins, some subset of 
individuals could be taken up to 23 days in a year, with some small 
number being taken across several sequential days, such that a small 
number of individuals could be interrupted during foraging in a manner 
and amount such that impacts to the energy budgets of females (from 
either losing feeding opportunities or expending considerable energy to 
find alternative feeding options) could cause them to forego 
reproduction for a year. Energetic impacts to males are generally 
meaningless to population rates unless they cause death, and it takes 
extreme energy deficits beyond what would ever be likely to result from 
these activities to cause the death of an adult marine mammal. As noted 
previously, however, foregone reproduction (especially for one year, 
which is the maximum predicted because the small number anticipated in 
any one year makes the probability that any individual would be 
impacted in this way twice in seven years very low) has far less of an 
impact on population rates than mortality and a small number of 
instances of foregone reproduction is not expected to adversely affect 
these two stocks through effects on annual rates of recruitment or 
survival. No mortality is anticipated or authorized for any of these 
stocks. One or two individuals from three stocks (see Table 24) are 
expected to be taken by PTS annually of likely low severity, with this 
unlikely to impact behaviors, opportunities, or detection capabilities 
to a degree that would interfere with reproductive success or survival 
of those individuals, let alone have effects on annual rates of 
recruitment or survival. For these reasons, in consideration of all of 
the effects of the Navy's activities combined, we have determined that 
the authorized take will have a negligible impact on all of the stocks 
of dolphins found in the vicinity of the HRC.

Dall's Porpoise

    In Table 26 below for porpoises, we indicate the total annual 
mortality, Level A and Level B harassment, and a number indicating the 
instances of total take as a percentage of abundance. Table 26 is 
unchanged from Table 79 in the 2018 HSTT final rule. For additional 
information and analysis supporting the negligible-impact analysis, see 
the Odontocetes discussion as well as the Dall's Porpoise discussion in 
the Group and Species-Specific Analyses section of the 2018 HSTT final 
rule, all of which remains applicable to this final rule unless 
specifically noted.

Table 26--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Porpoises in the HSTT Study Area and Number Indicating the Instances of Total Take as a Percentage
                                                                                       of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Instances of indicated types of incidental take (not all takes   Total takes          Abundance           Instances of total take as
                                                            represent separate individuals, especially for disturbance)   ---------------------------------------      percent of abundance
                                                        ------------------------------------------------------------------                                       -------------------------------
                                                             Level B harassment        Level A harassment
             Species                       Stock        -----------------------------------------------------              Total takes      Navy                   Total take as   Total take as
                                                                        TTS  (may                                             (entire    abundance    NMFS SARS    percentage of   percentage of
                                                          Behavioral      also                      Tissue     Mortality   study area)   in action    abundance     total Navy       total SAR
                                                         disturbance     include        PTS         damage                                  area                   abundance in      abundance
                                                                      disturbance)                                                                                  action area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Dall's porpoise..................  CA/OR/WA............       14,482        29,891          209            0            0       44,582        2,054       25,750           2,170             173
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
  and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
  predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.

    Below we compile and summarize the information that supports our 
determination that the Navy's activities will not adversely affect the 
CA/OR/WA stock of Dall's porpoises through effects

[[Page 41889]]

on annual rates of recruitment or survival.
    Dall's porpoise is not listed under the ESA and the stock status is 
considered ``unknown.'' No mortality or Level A harassment via tissue 
damage from exposure to explosives is expected or authorized for this 
stock.
    Most Level B harassments to Dall's porpoise from hull-mounted sonar 
(MF1) in the HSTT Study Area would result from received levels between 
154 and 166 dB SPL (85 percent). While harbor porpoises have been 
observed to be especially sensitive to human activity, the same types 
of responses have not been observed in Dall's porpoises. Dall's 
porpoises are typically notably longer than, and weigh more than twice 
as much as, harbor porpoises, making them generally less likely to be 
preyed upon and likely differentiating their behavioral repertoire 
somewhat from harbor porpoises. Further, they are typically seen in 
large groups and feeding aggregations, or exhibiting bow-riding 
behaviors, which is very different from the group dynamics observed in 
the more typically solitary, cryptic harbor porpoises, which are not 
often seen bow-riding. For these reasons, Dall's porpoises are not 
treated as an especially sensitive species (as compared to harbor 
porpoises which have a lower threshold for Level B harassment by 
behavioral disruption and more distant cutoff) but, rather, are 
analyzed similarly to other odontocetes. Therefore, the majority of 
Level B harassment takes are expected to be in the form of milder 
responses compared to higher level exposures. As discussed more fully 
in the 2018 HSTT final rule, we anticipate more severe effects from 
takes when animals are exposed to higher received levels.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance (measured against both the Navy-estimated 
abundance and the SAR) is 2,170 and 173 percent, respectively. Given 
the range of this stock (up the U.S. West Coast through Washington and 
sometimes beyond the U.S. EEZ), this information suggests that some 
smaller portion of the individuals of this stock will be taken, and 
that some subset of individuals within the stock will be taken 
repeatedly within the year (perhaps up to 42 days)--potentially over a 
fair number of sequential days, especially where individuals spend 
extensive time in the SOCAL range complex. Regarding the severity of 
those individual Level B harassment takes by behavioral disruption, 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, or sometimes moderate level, less likely to 
evoke a severe response). While interrupted feeding bouts are a known 
response and concern for odontocetes, we also know that there are often 
viable alternative habitat options in the relative vicinity. However, 
as noted, some of these takes could occur on a fair number of 
sequential days for this stock.
    The severity of TTS takes is expected to be low-level, of short 
duration, and mostly not in a frequency band that would be expected to 
interfere significantly with conspecific communication, echolocation, 
or other important low-frequency cues. Therefore, the associated lost 
opportunities and capabilities are not expected to impact reproduction 
or survival. For these same reasons (low level and the likely frequency 
band), while a small permanent loss of hearing sensitivity may include 
some degree of energetic costs for compensating or may mean some small 
loss of opportunities or detection capabilities, the estimated 209 
Level A harassment takes by PTS for Dall's porpoise is unlikely to 
impact behaviors, opportunities, or detection capabilities to a degree 
that would interfere with reproductive success or survival for most 
individuals. Because of the more substantial number of PTS takes, 
however, we acknowledge that a few animals could potentially incur 
permanent hearing loss of a higher degree that could potentially 
interfere with their successful reproduction and growth. Given the 
status of the stock, even if this occurred, it will not adversely 
impact annual rates of recruitment or survival.
    Altogether, the status of this stock is unknown, a portion of this 
stock will likely be taken (at a low to occasionally moderate level) 
over several days a year, and some smaller portion of the stock is 
expected to be taken on a relatively moderate to high number of days 
across the year, some of which could be sequential days. Though the 
majority of impacts are expected to be of a lower to sometimes moderate 
severity, the larger number of takes (in total and for certain 
individuals) for the Dall's porpoise makes it more likely 
(probabilistically) that a small number of individuals could be 
interrupted during foraging in a manner and amount such that impacts to 
the energy budgets of females (from either losing feeding opportunities 
or expending considerable energy to find alternative feeding options) 
could cause them to forego reproduction for a year. Energetic impacts 
to males are generally meaningless to population rates unless they 
cause death, and it takes extreme energy deficits beyond what would 
ever be likely to result from these activities to cause the death of an 
adult marine mammal. Similarly, we acknowledge the potential for this 
to occur to a few individuals out of the 209 total that might incur a 
higher degree of PTS. As noted previously, however, foregone 
reproduction (especially for only one year in seven, which is the 
maximum predicted because the small number anticipated in any one year 
makes the probability that any individual will be impacted in this way 
twice in seven years very low) has far less of an impact on population 
rates than mortality. Further, the small number of instances of 
foregone reproduction that could potentially result from PTS and/or the 
few repeated, more severe Level B harassment takes by behavioral 
disruption is not expected to adversely affect the stock through 
effects on annual rates of recruitment or survival, especially given 
the status of the species (not endangered or threatened; minimum 
population of 25,170 just within the U.S. EEZ) and residual PBR of 
Dall's porpoise (171.4). For these reasons, in consideration of all of 
the effects of the Navy's activities combined, we have determined that 
the authorized take will have a negligible impact on the CA/OR/WA stock 
of Dall's porpoises.

Pinnipeds

    In Tables 27 and 28 below for pinnipeds, we indicate the total 
annual mortality, Level A and Level B harassment, and a number 
indicating the instances of total take as a percentage of abundance. 
Tables 27 and 28 have been updated from Tables 80 and 81 in the 2018 
HSTT final rule, as appropriate, with the 2018 final SARs and updated 
information on mortality, as discussed above. For additional 
information and analysis supporting the negligible-impact analysis, see 
the Pinnipeds discussion in the Group and Species-Specific Analyses 
section of the 2018 HSTT final rule, all of which remains applicable to 
this final rule unless specifically noted.

[[Page 41890]]



 Table 27--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Pinnipeds in the HRC Portion of the HSTT Study Area and Number Indicating the Instances of Total
                                                                             Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                   Instances of indicated types of incidental take  (not all takes represent         Total takes                Abundance           Instances of total take as
                                               separate individuals, especially for disturbance)             ----------------------------------------------------      percent of abundance
                                  ---------------------------------------------------------------------------                                                    -------------------------------
                                           Level B harassment             Level A harassment                                             Total Navy
             Species              --------------------------------------------------------------              Total takes     Takes      abundance    Within EEZ   Total take as    EEZ take as
                                                           TTS (may                                             (entire      (within     inside and      Navy      percentage of   percentage of
                                        Behavioral           also                      Tissue     Mortality   study area)   NAVY EEZ)     outside     abundance     total Navy       Navy EEZ
                                        disturbance         include        PTS         damage                                            EEZ (HRC)      (HRC)        abundance       abundance
                                                         disturbance)                                                                                                  (HRC)           (HRC)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Hawaiian monk seal...............  143.................            62            1            0            0          206          195          169          169             122             115
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the HI take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals
  section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area used to
  generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately compare
  the take to the SARs abundance estimate.
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.


Table 28--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Pinnipeds in the SOCAL Portion of the HSTT Study Area and Number Indicating the Instances of Total
                                                                             Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Instances of indicated types of incidental take (not all takes   Total takes          Abundance           Instances of total take as
                                                            represent separate individuals, especially for disturbance)   ---------------------------------------      percent of abundance
                                                        ------------------------------------------------------------------                                       -------------------------------
                                                             Level B harassment        Level A harassment                                   Navy
             Species                       Stock        -----------------------------------------------------              Total takes   abundance                 Total take as   Total take as
                                                                        TTS (may                                             (entire     in action    NMFS SARS    percentage of   percentage of
                                                          Behavioral      also                      Tissue     Mortality   study area)      area      abundance     total Navy       total SAR
                                                         disturbance     include        PTS         damage                                (SOCAL)                  abundance in      abundance
                                                                      disturbance)                                                                                  action area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion..............  U.S.................      113,419         4,789           87            9         0.71      118,305        4,085      257,606           2,896              46
Guadalupe fur seal...............  Mexico..............        1,442            15            0            0            0        1,457        1,171       20,000             124               7
Northern fur seal................  California..........       15,167           124            1            0            0       15,292          886       14,050           1,726             109
Harbor seal......................  California..........        2,450         2,994            8            0            0        5,452          321       30,968           1,698              18
Northern elephant seal...........  California..........       42,916        17,955           97            2            0       60,970        4,108      179,000           1,484              34
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy action area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and
  beyond and abundance may only be predicted within the U.S. EEZ, while the Navy action area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
  predicted takes to both the abundance estimates for the action area, as well as the SARs.
For mortality takes there is an annual average of 0.71 California sea lions (i.e., where five takes could potentially occur divided by seven years to get the annual number of mortalities/
  serious injuries).

    Below we compile and summarize the information that supports our 
determination that the Navy's activities will not adversely affect any 
pinnipeds through effects on annual rates of recruitment or survival 
for any of the affected stocks addressed in this section.
    Five M/SI takes of California sea lions over the seven years of the 
rule, or 0.71 mortality annually, are authorized, which falls well 
below the insignificance threshold for residual PBR (13,685). No 
mortality is anticipated or authorized for any other pinniped stocks. A 
small number of Level A harassment takes by tissue damage are also 
authorized for two stocks (9 and 2 for California sea lions and 
northern elephant seals, respectively), which, as discussed in the 2018 
HSTT final rule, could range in impact from minor to something just 
less than M/SI that could seriously impact fitness. However, given the 
Navy's mitigation, exposure at the closer to the source and more severe 
end of the spectrum is less likely. Nevertheless, we cautiously assume 
some moderate impact on the individuals that experience these small 
numbers of take that could lower the individual's fitness within the 
year such that a female (assuming a 50 percent chance of it being a 
female) might forego reproduction for one year. As noted previously, 
foregone reproduction has less of an impact on population rates than 
death (especially for only one within seven years, which is the maximum 
predicted because the small number anticipated in any one year makes 
the probability that any individual would be impacted in this way twice 
in seven years very low) and these low numbers of instances (especially 
assuming the likelihood that only 50 percent of the takes would affect 
females) are not expected to impact annual rates of recruitment or 
survival, especially given the population sizes of these species.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), for Hawaiian monk seals and Guadalupe fur 
seals, the two species listed under the ESA, the estimated instances of 
takes as compared to the stock abundance does not exceed 124 percent, 
which suggests that some portion of these two stocks would be taken on 
one to a few days per year. For the remaining stocks, the number of 
estimated total instances of take compared to the abundance (measured 
against both the Navy-estimated abundance and the SAR) for these stocks 
is 1,484 to 2,896 percent and 18 to 40 percent, respectively. Given the 
ranges of these stocks (i.e., very large ranges, but with individuals 
often staying in the vicinity of haul outs), this information suggests 
that some very small portion of the individuals of these stocks will be 
taken, but that some subset of individuals within the stock will be 
taken repeatedly within the year (perhaps up to 58 days)--potentially 
over a fair number of sequential days. Regarding the severity of those 
individual Level B harassment takes by behavioral disruption, 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, which is considered a relatively low to occasionally moderate 
level for pinnipeds. However, as noted, some of these takes could occur 
on a fair number of sequential days for these stocks.
    As described in the 2018 HSTT final rule, the Hawaii and 4-Islands 
mitigation areas protect (by not using explosives and limiting MFAS 
within them) a significant portion of the

[[Page 41891]]

designated critical habitat for Hawaiian monk seals in the Main 
Hawaiian Islands, including all of it around the islands of Hawaii and 
Lanai, most around Maui, and good portions around Molokai and 
Kaho'olawe. As discussed, this protection reduces the overall number of 
takes, and further reduces the severity of effects by minimizing 
impacts near pupping beaches and in important foraging habitat.
    The severity of TTS takes are expected to be low-level, of short 
duration, and mostly not in a frequency band that would be expected to 
interfere significantly with conspecific communication, echolocation, 
or other important low-frequency cues that would affect the 
individual's reproduction or survival. For these same reasons (low 
level and frequency band), while a small permanent loss of hearing 
sensitivity may include some degree of energetic costs for compensating 
or may mean some small loss of opportunities or detection capabilities, 
the one to eight estimated Level A harassment takes by PTS for monk 
seals, northern fur seals, and harbor seals are unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
would interfere with reproductive success or survival of any 
individuals, even if it were to be experienced by an animal that also 
experiences one or more Level B harassment takes by behavioral 
disruption. Because of the high number of PTS takes for California sea 
lions and northern elephant seals (87 and 97, respectively); however, 
we acknowledge that a few animals could potentially incur permanent 
hearing loss of a higher degree that could potentially interfere with 
their successful reproduction and growth. Given the status of the 
stocks (along with residual PBRs of 13,686 and 4,873, respectively), 
even if this occurred, it will not adversely impact annual rates of 
recruitment or survival.
    Altogether, any individual Hawaiian monk seal and Guadalupe fur 
seal would be taken no more than a few days in any year, with none of 
the expected take anticipated to affect individual reproduction or 
survival, let alone annual rates of recruitment and survival. With all 
other stocks, only a very small portion of the stock will be taken in 
any manner. Of those taken, some individuals will be taken by Level B 
harassment (at a moderate or sometimes low level) over several days a 
year, and some smaller portion of those taken will be on a relatively 
moderate to high number of days across the year (up to 58), a fair 
number of which will likely be sequential days. Though the majority of 
impacts are expected to be of a lower to sometimes moderate severity, 
the repeated takes over a potentially fair number of sequential days 
for some individuals makes it more likely that some number of 
individuals could be interrupted during foraging in a manner and amount 
such that impacts to the energy budgets of females (from either losing 
feeding opportunities or expending considerable energy to find 
alternative feeding options) could cause them to forego reproduction 
for a year (energetic impacts to males are generally meaningless to 
population rates unless they cause death, and it takes extreme energy 
deficits beyond what would ever be likely to result from these 
activities to cause the death of an adult marine mammal). As noted 
previously, however, foregone reproduction (especially for only one 
year within seven, which is the maximum predicted because the small 
number anticipated in any one year makes the probability that any 
individual will be impacted in this way twice in seven years very low) 
has far less of an impact on population rates than mortality and a 
relatively small number of instances of foregone reproduction (as 
compared to the stock abundance and residual PBR) is not expected to 
adversely affect the stock through effects on annual rates of 
recruitment or survival, especially given the status of these stocks. 
Accordingly, we do not anticipate the relatively small number of 
individual Northern fur seals or harbor seals that might be taken over 
repeated days within the year in a manner that results in one year of 
foregone reproduction to adversely affect the stocks through effects on 
rates of recruitment or survival, given the status of the stocks, which 
are respectively increasing and stable with abundances of 14,050 and 
30,968 and residual PBRs of 449 and 1,598.
    For California sea lions, given the very high abundance and 
residual PBR (257,606 and 13,685, respectively), as well as the 
increasing status of the stock in the presence of similar levels of 
Navy activities over past years--the impacts of 0.71 annual 
mortalities, potential foregone reproduction for up to nine individuals 
in a year taken by tissue damage, the effects of Level A harassment by 
PTS, and some relatively small number of individuals taken as a result 
of repeated behavioral harassment over a fair number of sequential days 
are not expected to adversely affect the stock through effects on 
annual rates of recruitment or survival. Similarly, for Northern 
elephant seals, given the very high abundance and residual PBR (179,000 
and 4,873, respectively), as well as the increasing status of the stock 
in the presence of similar levels of Navy activities over past years, 
the impacts of potential foregone reproduction for up to two 
individuals in a year taken by tissue damage, the effects of Level A 
harassment by PTS, and some relatively small number of individuals 
taken as a result of repeated behavioral harassment over a fair number 
of sequential days are not expected to adversely affect the stock 
through effects on annual rates of recruitment or survival. For these 
reasons, in consideration of all of the effects of the Navy's 
activities combined (M/SI, Level A harassment, and Level B harassment), 
we have determined that the authorized take will have a negligible 
impact on all pinniped stocks.

Determination

    The 2018 HSTT final rule included a detailed discussion of all of 
the anticipated impacts on the affected species and stocks from serious 
injury or mortality, Level A harassment, and Level B harassment; 
impacts on habitat; and how the Navy's mitigation and monitoring 
measures reduce the number and/or severity of adverse effects. We 
evaluated how these impacts and mitigation measures are expected to 
combine, annually, to affect individuals of each species and stock. 
Those effects were then evaluated in the context of whether they are 
reasonably likely to impact reproductive success or survivorship of 
individuals and then, if so, further analyzed to determine whether 
there would be effects on annual rates of recruitment or survival that 
would adversely affect the species or stock.
    As described above, the basis for the negligible impact 
determination is the assessment of effects on annual rates of 
recruitment and survival. Accordingly, the analysis included in the 
2018 HSTT final rule used annual activity levels, the best available 
science, and approved methods to predict the annual impacts to marine 
mammals, which were then analyzed in the context of whether each 
species or stock would incur more than a negligible impact based on 
anticipated adverse impacts to annual rates of recruitment or survival. 
As we have described above, none of the factors upon which the 
conclusions in the 2018 HSTT final rule were based have changed. 
Therefore, even though this final rule includes two additional years, 
because our findings are based on annual rates of recruitment and 
survival, and little has changed that would change our 2018 HSTT final 
rule annual analyses, it is appropriate to rely on those analyses, as 
well as the new

[[Page 41892]]

information and analysis discussed above, for this final rule.
    Based on the applicable information and analysis from the 2018 HSTT 
final rule as updated with the information and analysis contained 
herein on the potential and likely effects of the specified activities 
on the affected marine mammals and their habitat, and taking into 
consideration the implementation of the monitoring and mitigation 
measures, NMFS finds that the incidental take from the specified 
activities will have a negligible impact on all affected marine mammal 
species and stocks.

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 or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Classification

Endangered Species Act

    There are nine marine mammal species under NMFS jurisdiction that 
are listed as endangered or threatened under the ESA with confirmed or 
possible occurrence in the HSTT Study Area: Blue whale, fin whale, gray 
whale, humpback whale (Mexico and Central America DPSs), sei whale, 
sperm whale, false killer whale (Main Hawaiian Islands Insular DPS), 
Hawaiian monk seal, and Guadalupe fur seal. There is also ESA-
designated critical habitat for Hawaiian monk seals and Main Hawaiian 
Islands Insular false killer whales. The Navy consulted with NMFS 
pursuant to section 7 of the ESA for HSTT activities. NMFS also 
consulted internally on the issuance of the 2018 HSTT regulations and 
LOAs under section 101(a)(5)(A) of the MMPA. NMFS issued a Biological 
Opinion on December 10, 2018 concluding that the issuance of the 2018 
HSTT final rule and subsequent LOAs are not likely to jeopardize the 
continued existence of the threatened and endangered species under 
NMFS' jurisdiction and are not likely to result in the destruction or 
adverse modification of critical habitat in the HSTT Study Area.
    The 2018 Biological Opinion included specified conditions under 
which NMFS would be required to reinitiate section 7 consultation. The 
agency reviewed these specified conditions for this rulemaking and 
determined that reinitiation of consultation was not warranted. The 
incidental take statement that accompanied the 2018 Biological Opinion 
has been amended to cover the seven-year period of the rule. The 2018 
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

    Federal agency actions that are likely to injure national marine 
sanctuary resources are subject to consultation with the Office of 
National Marine Sanctuaries (ONMS) under section 304(d) of the National 
Marine Sanctuaries Act (NMSA). There are two national marine 
sanctuaries in the HSTT Study Area, the Hawaiian Islands Humpback Whale 
National Marine Sanctuary and the Channel Islands National Marine 
Sanctuary. NMFS has fulfilled its responsibilities and completed all 
requirements under the NMSA.

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 our proposed actions and alternatives with respect 
to potential impacts on the human environment. NMFS participated as a 
cooperating agency on the 2018 HSTT FEIS/OEIS (published on October 26, 
2018, http://www.hstteis.com) which evaluated impacts from Navy 
training and testing activities in the HSTT Study Area for the 
reasonably foreseeable future (including through 2025). In accordance 
with 40 CFR 1506.3, NMFS independently reviewed and evaluated the 2018 
HSTT FEIS/OEIS and determined that it was adequate and sufficient to 
meet our responsibilities under NEPA for the issuance of the 2018 HSTT 
final rule and associated LOAs. NOAA therefore adopted the 2018 HSTT 
FEIS/OEIS.
    In accordance with 40 CFR 1502.9 and the information and analysis 
contained in this final rule, NMFS has determined that this final rule 
and the subsequent LOAs will not result in impacts that were not fully 
considered in the 2018 HSTT FEIS/OEIS. In addition, as indicated in 
this final rule, the addition of two years of authorized incidental 
take associated with the same activities conducted in the same 
geographic area and having the same potential effects on the same 
species and stocks is not a substantial change to the action, nor are 
there significant new circumstances or information relevant to 
environmental concerns or its impacts. Therefore, NMFS has determined 
that the 2018 HSTT FEIS/OEIS and 2018 NMFS ROD remain valid, and there 
is no need to supplement either document for this rulemaking.

Regulatory Flexibility Act

    The Office of Management and Budget has determined that this rule 
is not significant for purposes of Executive Order 12866.
    Pursuant to the Regulatory Flexibility Act (RFA), the Chief Counsel 
for Regulation of the Department of Commerce 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 Under the Administrative Procedure 
Act

    NMFS has determined that there is good cause under the 
Administrative Procedure Act (5 U.S.C. 553(d)) to waive the 30-day 
delay in the effective date for this rule. This rule relieves the Navy 
from the restrictions of the take prohibitions under the MMPA by 
granting the Navy's request for incidental take authorization under 
MMPA section 101(a)(5)(A). In addition, there is good cause to waive 
the 30-day effective date period because the regulations are identical 
to those that the Navy has been implementing since November 2018 
(except for a small number of minor, technical clarifications that do 
not affect implementation). The only substantive change in the 
regulations is to extend the mitigation measures and the monitoring and 
reporting requirements for an additional two years, until December 20, 
2025. The Navy is the only entity affected by the regulations, the Navy 
specifically requested extension of the regulatory requirements for the 
two years, and the Navy has fully agreed to these requirements for the 
additional two years through its application for incidental take 
authorization. The Navy is anticipating finalization of the rule. For 
all these reasons, there is no need for a period of time following 
publication of the rule for the Navy to bring its training and testing 
operations into compliance with the requirements of the rule.

[[Page 41893]]

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: June 26, 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 H to read as follows:
Subpart H--Taking and Importing Marine Mammals; U.S. Navy's Hawaii-
Southern California Training and Testing (HSTT)
Sec.
218.70 Specified activity and geographical region.
218.71 Effective dates.
218.72 Permissible methods of taking.
218.73 Prohibitions.
218.74 Mitigation requirements.
218.75 Requirements for monitoring and reporting.
218.76 Letters of Authorization.
218.77 Renewals and modifications of Letters of Authorization.
218.78-218.79 [Reserved]

Subpart H--Taking and Importing Marine Mammals; U.S. Navy's Hawaii-
Southern California Training and Testing (HSTT)


Sec.  218.70   Specified activity and geographical region.

    (a) Regulations in this subpart apply only to the U.S. Navy (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 Letters of Authorization (LOAs) only if it occurs 
within the Hawaii-Southern California Training and Testing (HSTT) Study 
Area, which includes established operating and warning areas across the 
north-central Pacific Ocean, from the mean high tide line in Southern 
California west to Hawaii and the International Date Line. The Study 
Area includes the at-sea areas of three existing range complexes, the 
Hawaii Range Complex (HRC), the Southern California Range Complex 
(SOCAL), and the Silver Strand Training Complex, and overlaps a portion 
of the Point Mugu Sea Range (PMSR). Also included in the Study Area are 
Navy pierside locations in Hawaii and Southern California, Pearl 
Harbor, San Diego Bay, and the transit corridor on the high seas where 
sonar training and testing may occur.
    (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) Electronic warfare;
    (iv) Expeditionary warfare;
    (v) Mine warfare;
    (vi) Surface warfare; and
    (vii) Pile driving.
    (2) Testing. (i) Naval Air Systems Command Testing Activities;
    (ii) Naval Sea Systems Command Testing Activities;
    (iii) Office of Naval Research Testing Activities; and
    (iv) Naval Information Warfare Systems Command.


Sec.  218.71  Effective dates.

    Regulations in this subpart are effective from July 10, 2020, 
through December 20, 2025.


Sec.  218.72  Permissible methods of taking.

    (a) Under LOAs issued pursuant to Sec. Sec.  216.106 of this 
chapter and 218.76, the Holder of the LOAs (hereinafter ``Navy'') may 
incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  218.70(b) by Level A harassment and Level B 
harassment associated with the use of active sonar and other acoustic 
sources and explosives as well as serious injury or mortality 
associated with vessel strikes and explosives, provided the activity is 
in compliance with all terms, conditions, and requirements of these 
regulations in this subpart and the applicable LOAs.
    (b) The incidental take of marine mammals by the activities listed 
in Sec.  218.70(c) is limited to the following species:

                                            Table 1 to Sec.   218.72
----------------------------------------------------------------------------------------------------------------
                 Species                                                   Stock
----------------------------------------------------------------------------------------------------------------
Blue whale...............................  Central North Pacific.
Blue whale...............................  Eastern North Pacific.
Bryde's whale............................  Eastern Tropical Pacific.
Bryde's whale............................  Hawaii.
Fin whale................................  CA/OR/WA.
Fin whale................................  Hawaiian.
Humpback whale...........................  CA/OR/WA.
Humpback whale...........................  Central North Pacific.
Minke whale..............................  CA/OR/WA.
Minke whale..............................  Hawaii.
Sei whale................................  Eastern North Pacific.
Sei whale................................  Hawaii.
Gray whale...............................  Eastern North Pacific.
Gray whale...............................  Western North Pacific.
Sperm whale..............................  CA/OR/WA.
Sperm whale..............................  Hawaii.
Dwarf sperm whale........................  Hawaii.
Pygmy sperm whale........................  Hawaii.
Kogia whales.............................  CA/OR/WA.
Baird's beaked whale.....................  CA/OR/WA.
Blainville's beaked whale................  Hawaii.
Cuvier's beaked whale....................  CA/OR/WA.
Cuvier's beaked whale....................  Hawaii.
Longman's beaked whale...................  Hawaii.
Mesoplodon spp...........................  CA/OR/WA.

[[Page 41894]]

 
Bottlenose dolphin.......................  California Coastal.
Bottlenose dolphin.......................  CA/OR/WA Offshore.
Bottlenose dolphin.......................  Hawaii Pelagic.
Bottlenose dolphin.......................  Kauai & Niihau.
Bottlenose dolphin.......................  Oahu.
Bottlenose dolphin.......................  4-Island.
Bottlenose dolphin.......................  Hawaii.
False killer whale.......................  Hawaii Pelagic.
False killer whale.......................  Main Hawaiian Islands Insular.
False killer whale.......................  Northwestern Hawaiian Islands.
Fraser's dolphin.........................  Hawaii.
Killer whale.............................  Eastern North Pacific (ENP) Offshore.
Killer whale.............................  ENP Transient/West Coast Transient.
Killer whale.............................  Hawaii.
Long-beaked common dolphin...............  California.
Melon-headed whale.......................  Hawaiian Islands.
Melon-headed whale.......................  Kohala Resident.
Northern right whale dolphin.............  CA/OR/WA.
Pacific white-sided dolphin..............  CA/OR/WA.
Pantropical spotted dolphin..............  Hawaii Island.
Pantropical spotted dolphin..............  Hawaii Pelagic.
Pantropical spotted dolphin..............  Oahu.
Pantropical spotted dolphin..............  4-Island.
Pygmy killer whale.......................  Hawaii.
Pygmy killer whale.......................  Tropical.
Risso's dolphin..........................  CA/OR/WA.
Risso's dolphin..........................  Hawaii.
Rough-toothed dolphin....................  Hawaii.
Short-beaked common dolphin..............  CA/OR/WA.
Short-finned pilot whale.................  CA/OR/WA.
Short-finned pilot whale.................  Hawaii.
Spinner dolphin..........................  Hawaii Island.
Spinner dolphin..........................  Hawaii Pelagic.
Spinner dolphin..........................  Kauai & Niihau.
Spinner dolphin..........................  Oahu & 4-Island.
Striped dolphin..........................  CA/OR/WA.
Striped dolphin..........................  Hawaii.
Dall's porpoise..........................  CA/OR/WA.
California sea lion......................  U.S.
Guadalupe fur seal.......................  Mexico.
Northern fur seal........................  California.
Harbor seal..............................  California.
Hawaiian monk seal.......................  Hawaii.
Northern elephant seal...................  California.
----------------------------------------------------------------------------------------------------------------
Note to Table 1: CA/OR/WA = California/Oregon/Washington.

Sec.  218.73  Prohibitions.

    Notwithstanding incidental takings contemplated in Sec.  218.72(a) 
and authorized by LOAs issued under Sec. Sec.  216.106 of this chapter 
and 218.76, no person in connection with the activities listed in Sec.  
218.70(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 chapter and 218.76;
    (b) Take any marine mammal not specified in Sec.  218.72(b);
    (c) Take any marine mammal specified in Sec.  218.72(b) in any 
manner other than as specified in the LOAs; or
    (d) Take a marine mammal specified in Sec.  218.72(b) if NMFS 
determines such taking results in more than a negligible impact on the 
species or stocks of such marine mammal.


Sec.  218.74  Mitigation requirements.

    When conducting the activities identified in Sec.  218.70(c), the 
mitigation measures contained in any LOAs issued under Sec. Sec.  
216.106 of this chapter and 218.76 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 HSTT Study Area for each 
applicable activity category or stressor category and includes acoustic 
stressors (i.e., active sonar, air guns, pile driving, 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 mat weave and obstacle 
loading), 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, 
monitoring, 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

[[Page 41895]]

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 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 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 on the 
ship or aircraft conducting the activity.
    (ii) Mitigation zone and requirements. (A) During the activity, at 
1,000 yards (yd) Navy personnel must power down 6 decibels (dB), at 500 
yd Navy personnel must power down an additional 4 dB (for a total of 10 
dB), and at 200 yd Navy personnel must shut down for low-frequency 
active sonar >=200 dB and hull-mounted mid-frequency active sonar; or 
at 200 yd Navy personnel must shut down for low-frequency active sonar 
<200 dB, mid-frequency active sonar sources that are not hull-mounted, 
and high-frequency active sonar.
    (B) Prior to the start of the activity (e.g., when maneuvering on 
station), Navy personnel must observe the mitigation zone for floating 
vegetation; if floating vegetation is observed, Navy personnel must 
relocate or delay the start of active sonar transmission until the 
mitigation zone is clear. Navy personnel must also observe the 
mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must relocate or delay the start of active sonar 
transmission.
    (C) 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 total) 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.
    (D) 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.
    (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 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 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) Air guns--(i) Number of Lookouts and observation platform. One 
Lookout positioned on a ship or pierside.
    (ii) Mitigation zone and requirements. 150 yd around the air gun.
    (A) Prior to the initial start of the activity (e.g., when 
maneuvering on station), Navy personnel must observe the mitigation 
zone for floating vegetation; if floating vegetation is observed, Navy 
personnel must relocate or delay the start until the mitigation zone is 
clear. Navy personnel must also observe the mitigation zone for marine 
mammals; if marine mammals are observed, Navy personnel must relocate 
or delay the start of air gun use.
    (B) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease air gun use.
    (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 air gun use) 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 air 
gun; the mitigation zone has been clear from any additional sightings 
for 30 min; or for mobile activities, the air gun has transited a 
distance equal to double that of the mitigation zone size beyond the 
location of the last sighting.
    (4) Pile driving. Pile driving and pile extraction sound during 
Elevated Causeway System training.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned on the shore, the elevated causeway, or a small boat.
    (ii) Mitigation zone and requirements. 100 yd around the pile 
driver.
    (A) Prior to the initial start of the activity (for 30 min), Navy 
personnel must observe the mitigation zone for floating vegetation; if 
floating vegetation is observed, Navy personnel must delay the start 
until the mitigation zone is clear. Navy personnel also must observe 
the mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must delay the start of pile driving or vibratory pile 
extraction.
    (B) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease impact pile driving or vibratory pile extraction.
    (C) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. The 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 pile driving or pile extraction) until one of the 
following conditions has been met: The animal is observed exiting the 
mitigation zone;

[[Page 41896]]

the animal is thought to have exited the mitigation zone based on a 
determination of its course, speed, and movement relative to the pile 
driving location; or the mitigation zone has been clear from any 
additional sightings for 30 min.
    (5) 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)(8)(i) and (a)(18)(i) of this section.
    (ii) Mitigation zone and requirements. 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 start of the activity, Navy personnel must observe 
the mitigation zone for floating vegetation; if floating vegetation is 
observed, Navy personnel must relocate or delay the start of weapons 
firing until the mitigation zone is clear. Navy personnel must also 
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.
    (6) 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 in those assets (e.g., safety observers, 
evaluators) must support observing the mitigation zone for applicable 
biological resources while performing their regular duties.
    (ii) Mitigation zone and requirements. 600 yd around an explosive 
sonobuoy.
    (A) Prior to the initial start of the activity (e.g., during 
deployment of a sonobuoy field, which typically lasts 20-30 min), Navy 
personnel must observe the mitigation zone for floating vegetation; if 
floating vegetation is observed, Navy personnel must relocate or delay 
the start of sonobuoy or source/receiver pair detonations until the 
mitigation zone is clear. 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.
    (B) 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.
    (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 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.
    (D) 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), these Navy assets must assist in the visual 
observation of the area where detonations occurred.
    (7) Explosive torpedoes--(i) Number of Lookouts and observation 
platform. One Lookout positioned in an aircraft. If additional 
platforms are participating in the activity, Navy personnel positioned 
in those assets (e.g., safety observers, evaluators) must support 
observing the mitigation zone for applicable biological resources while 
performing their regular duties.
    (ii) Mitigation zone and requirements. 2,100 yd around the intended 
impact location.
    (A) Prior to the initial start of the activity (e.g., during 
deployment of the target), Navy personnel must observe the mitigation 
zone for floating vegetation and jellyfish aggregations; if floating 
vegetation or jellyfish aggregations are observed, Navy personnel must 
relocate or delay the start of firing until the mitigation zone is 
clear. 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.
    (B) During the activity, Navy personnel must observe for marine 
mammals and jellyfish aggregations; if marine mammals or jellyfish 
aggregations are observed, Navy personnel must cease 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 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.
    (D) 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

[[Page 41897]]

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), these Navy assets must assist in the visual 
observation of the area where detonations occurred.
    (8) 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)(5)(i) of this section. If additional platforms 
are participating in the activity, Navy personnel positioned in those 
assets (e.g., safety observers, evaluators) must support observing the 
mitigation zone for applicable biological resources while performing 
their regular duties.
    (ii) Mitigation zone and requirements. (A) 200 yd around the 
intended impact location for air-to-surface activities using explosive 
medium-caliber projectiles.
    (B) 600 yd around the intended impact location for surface-to-
surface activities using explosive medium-caliber projectiles.
    (C) 1,000 yd around the intended impact location for surface-to-
surface activities using explosive large-caliber projectiles.
    (D) Prior to the start of the activity (e.g., when maneuvering on 
station), Navy personnel must observe the mitigation zone for floating 
vegetation; if floating vegetation is observed, Navy personnel must 
relocate or delay the start of firing until the mitigation zone is 
clear. Navy personnel also 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 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), these Navy assets must assist in the visual 
observation of the area where detonations occurred.
    (9) 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 in those assets (e.g., 
safety observers, evaluators) must support observing the mitigation 
zone for applicable biological resources while performing their regular 
duties.
    (ii) Mitigation zone and requirements. (A) 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 floating vegetation; if floating vegetation is 
observed, Navy personnel must relocate or delay the start of firing 
until the mitigation zone is clear. Navy personnel also 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 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), these Navy assets will assist in the visual 
observation of the area where detonations occurred.
    (10) 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 in those assets (e.g., safety observers, 
evaluators) must support observing the mitigation zone for applicable 
biological resources while performing their regular duties.
    (ii) Mitigation zone and requirements. 2,500 yd around the intended 
target.
    (A) Prior to the initial start of the activity (e.g., when arriving 
on station), Navy personnel must observe the mitigation zone for 
floating vegetation; if floating vegetation is observed, Navy personnel 
must relocate or delay the start of bomb deployment until the 
mitigation zone is clear. Navy personnel also must observe the 
mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must relocate or delay the start of bomb deployment.
    (B) During the activity (e.g., during target approach), Navy 
personnel must

[[Page 41898]]

observe the mitigation zone for marine mammals; if marine mammals are 
observed, Navy personnel must cease bomb deployment.
    (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 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 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.
    (D) 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), these Navy assets must assist in the visual 
observation of the area where detonations occurred.
    (11) 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 in those 
assets (e.g., safety observers, evaluators) must support observing the 
mitigation zone for applicable biological resources while performing 
their regular duties.
    (ii) Mitigation zone and requirements. 2.5 nautical miles (nmi) 
around the target ship hulk.
    (A) 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 floating vegetation and jellyfish aggregations; if 
floating vegetation or jellyfish aggregations are observed, Navy 
personnel must delay the start of firing until the mitigation zone is 
clear. Navy personnel also must conduct aerial observations of the 
mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must delay the start of firing.
    (B) 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.
    (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 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.
    (D) 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), these Navy assets will assist in the visual 
observation of the area where detonations occurred.
    (12) 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 when implementing the 
smaller mitigation zone.
    (B) Two Lookouts (one must be positioned in an aircraft and one 
must be on a small boat) when implementing the larger mitigation zone.
    (C) If additional platforms are participating in the activity, Navy 
personnel positioned in those assets (e.g., safety observers, 
evaluators) must support observing the mitigation zone for applicable 
biological resources while performing their regular duties.
    (ii) Mitigation zone and requirements. (A) 600 yd around the 
detonation site for activities using 0.1-5 lb net explosive weight.
    (B) 2,100 yd around the detonation site for activities using 6-650 
lb net explosive weight (including high explosive target mines).
    (C) 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 floating vegetation; if 
floating vegetation is observed, Navy personnel must relocate or delay 
the start of detonations until the mitigation zone is clear. Navy 
personnel also must observe the mitigation zone for marine mammals; if 
marine mammals are observed, Navy personnel must relocate or delay the 
start of detonations.
    (D) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals, concentrations of seabirds, and individual 
foraging seabirds; if marine mammals, concentrations of seabirds, or 
individual foraging seabirds are observed, Navy personnel must cease 
detonations.
    (E) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity or a sighting of seabird 
concentrations or individual foraging seabirds during the activity. 
Navy personnel must allow a sighted animal 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

[[Page 41899]]

follow established incident reporting procedures. If additional 
platforms are supporting this activity (e.g., providing range 
clearance), these Navy assets must assist in the visual observation of 
the area where detonations occurred.
    (13) 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 must serve as an additional Lookout if 
aircraft are used during the activity, 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 in those assets (e.g., safety observers, 
evaluators) must support observing the mitigation zone for applicable 
biological resources while performing their regular duties.
    (ii) Mitigation zone and requirements. (A) 500 yd around the 
detonation site during activities under positive control using 0.1-20 
lb net explosive weight.
    (B) 1,000 yd around the detonation site during all activities using 
time-delay fuses (0.1-29 lb net explosive weight) and during activities 
under positive control using 21-60 lb net explosive weight charges.
    (C) Prior to the initial start of the activity (e.g., when 
maneuvering on station for activities under positive control; 30 min 
for activities using time-delay firing devices), Navy personnel must 
observe the mitigation zone for floating vegetation; if floating 
vegetation is observed, Navy personnel must relocate or delay the start 
of detonations or fuse initiation until the mitigation zone is clear. 
Navy personnel also 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.
    (D) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals, concentrations of seabirds, and individual 
foraging seabirds (in the water and not on shore); if marine mammals, 
concentrations of seabirds, or individual foraging seabirds are 
observed, Navy personnel 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 (0.1-29 lb. net explosive 
weight) to exceed 10 min.
    (E) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity or a sighting of seabird 
concentrations or individual foraging seabirds during the activity. 
Navy personnel must allow a sighted animal 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 detonation site; or the mitigation zone 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.
    (F) 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), these Navy 
assets must assist in the visual observation of the area where 
detonations occurred.
    (14) 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 
in those assets (e.g., safety observers, evaluators) must support 
observing the mitigation zone for applicable biological resources while 
performing their regular duties.
    (ii) Mitigation zone and requirements. 200 yd around the intended 
detonation location.
    (A) Prior to the initial start of the activity (e.g., when 
maneuvering on station), Navy personnel must observe the mitigation 
zone for floating vegetation; if floating vegetation is observed, Navy 
personnel must relocate or delay the start of detonations until the 
mitigation zone is clear. Navy personnel also must observe the 
mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must relocate or delay the start of detonations.
    (B) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease detonations.
    (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 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.
    (D) 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), these Navy assets will assist in the visual 
observation of the area where detonations occurred.
    (15) Underwater demolition multiple charge--mat weave and obstacle 
loading exercises--(i) Number of Lookouts and observation platform. Two 
Lookouts (one must be positioned

[[Page 41900]]

on a small boat and one must be positioned on shore from an elevated 
platform). If additional platforms are participating in the activity, 
Navy personnel positioned in those assets (e.g., safety observers, 
evaluators) must support observing the mitigation zone for applicable 
biological resources while performing their regular duties.
    (ii) Mitigation zone and requirements. 700 yd around the intended 
detonation location.
    (A) Prior to the initial start of the activity, or 30 min prior to 
the first detonation, the Lookout positioned on a small boat must 
observe the mitigation zone for floating vegetation and marine mammals; 
if floating vegetation or marine mammals are observed, Navy personnel 
must delay the start of detonations until the mitigation zone is clear. 
For 10 min prior to the first detonation, the Lookout positioned on 
shore must use binoculars to observe the mitigation zone for marine 
mammals; if marine mammals are observed, Navy personnel must delay the 
start of detonations.
    (B) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease detonations.
    (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 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 
detonation location; or the mitigation zone has been clear from any 
additional sightings for 10 min (as determined by the Navy shore 
observer).
    (D) After completion of the activity (for 30 min), the Lookout 
positioned on a small boat 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), these Navy assets must 
assist in the visual observation of the area where detonations 
occurred.
    (16) 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 operated 
autonomously; or when impracticable based on mission requirements 
(e.g., during Amphibious Assault--Battalion Landing exercise).
    (i) Number of Lookouts and observation platform. One Lookout must 
be on the vessel that is underway.
    (ii) Mitigation zone and requirements. (A) 500 yd around whales.
    (B) 200 yd around all other marine mammals (except bow-riding 
dolphins and pinnipeds hauled out on man-made navigational structures, 
port structures, and vessels).
    (iii) 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.
    (iv) Incident reporting procedures. If a marine mammal vessel 
strike occurs, Navy personnel must follow the established incident 
reporting procedures.
    (17) 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.
    (ii) Mitigation zone and requirements. 250 yd around marine 
mammals.
    (iii) During the activity. 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.
    (18) 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)(5)(i) of this section.
    (ii) Mitigation zone and requirements. 200 yd around the intended 
impact location.
    (A) Prior to the start of the activity (e.g., when maneuvering on 
station), Navy personnel must observe the mitigation zone for floating 
vegetation; if floating vegetation is observed, Navy personnel must 
relocate or delay the start of firing until the mitigation zone is 
clear. Navy personnel also must observe the mitigation zone for marine 
mammals; if marine mammals are observed, Navy personnel must relocate 
or delay the start of firing.
    (B) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease 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 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.
    (19) 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. 900 yd around the intended 
impact location.
    (A) 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 floating vegetation; if floating vegetation is 
observed, Navy personnel must relocate or delay the start of firing 
until the mitigation zone is clear. Navy personnel also must observe 
the mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must relocate or delay the start of firing.
    (B) During the activity, Navy personnel must observe the mitigation 
zone for marine mammals; if marine mammals are observed, Navy personnel 
must cease firing.
    (C) 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

[[Page 41901]]

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.
    (20) 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. 1,000 yd around the intended 
target.
    (A) Prior to the initial start of the activity (e.g., when arriving 
on station), Navy personnel must observe the mitigation zone for 
floating vegetation; if floating vegetation is observed, Navy personnel 
must relocate or delay the start of bomb deployment or mine laying 
until the mitigation zone is clear. Navy personnel also 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.
    (B) 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.
    (C) 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 in the Hawaii Range Complex 
for sonar, explosives, and vessel strikes--(i) Mitigation area 
requirements--(A) Hawaii Island Mitigation Area (year-round)--(1) 
Except as provided in paragraph (b)(1)(i)(A)(2) of this section, Navy 
personnel must not conduct more than 300 hours of MF1 surface ship 
hull-mounted mid-frequency active sonar or 20 hours of MF4 dipping 
sonar annually, or use explosives that could potentially result in 
takes of marine mammals during training and testing.
    (2) Should national security require conduct of more than 300 hours 
of MF1 surface ship hull-mounted mid-frequency active sonar or 20 hours 
of MF4 dipping sonar, or use of explosives that could potentially 
result in the take of marine mammals during training or testing, Naval 
units 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 or explosives usage) in its annual activity reports 
submitted to NMFS.
    (B) 4-Islands Region Mitigation Area (November 15-April 15 for 
active sonar; year-round for explosives)--(1) Except as provided in 
paragraph (b)(1)(i)(B)(2) of this section, Navy personnel must not use 
MF1 surface ship hull-mounted mid-frequency active sonar or explosives 
that could potentially result in takes of marine mammals during 
training and testing.
    (2) Should national security require use of MF1 surface ship hull-
mounted mid-frequency active sonar or explosives that could potentially 
result in the take of marine mammals during training or testing, Naval 
units 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 or explosives usage) in its annual activity reports 
submitted to NMFS.
    (C) Humpback Whale Special Reporting Areas (December 15-April 15). 
Navy personnel must report the total hours of surface ship hull-mounted 
mid-frequency active sonar used in the special reporting areas in its 
annual training and testing activity reports submitted to NMFS.
    (D) Humpback Whale Awareness Notification Message Area (November-
April). (1) Navy personnel must issue a seasonal awareness notification 
message to alert ships and aircraft operating in the area to the 
possible presence of concentrations of large whales, including humpback 
whales.
    (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 large whale species (including 
humpback whales).
    (3) Platforms must use the information from the awareness 
notification message to assist their visual observation of applicable 
mitigation zones during training and testing activities and to aid in 
the implementation of procedural mitigation.
    (ii) [Reserved]
    (2) Mitigation areas for marine mammals in the Southern California 
portion of the study area for sonar, explosives, and vessel strikes--
(i) Mitigation area requirements--(A) San Diego Arc, San Nicolas 
Island, and Santa Monica/Long Beach Mitigation Areas (June 1-October 
31). (1) Except as provided in paragraph (b)(2)(i)(A)(2) of this 
section, Navy personnel must not conduct more than a total of 200 hours 
of MF1 surface ship hull-mounted mid-frequency active sonar in the 
combined areas, excluding normal maintenance and systems checks, during 
training and testing.
    (2) Should national security require conduct of more than 200 hours 
of MF1 surface ship hull-mounted mid-frequency active sonar in the 
combined areas during training and testing (excluding normal 
maintenance and systems checks), Naval units 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) in its 
annual activity reports submitted to NMFS.
    (3) Except as provided in paragraph (b)(2)(i)(A)(4) of this 
section, within the San Diego Arc Mitigation Area, Navy personnel must 
not use explosives that could potentially result in the take of marine 
mammals during large-caliber gunnery, torpedo, bombing, and missile 
(including 2.75-inch rockets) activities during training and testing.
    (4) Should national security require use of explosives that could 
potentially result in the take of marine mammals during large-caliber 
gunnery, torpedo,

[[Page 41902]]

bombing, and missile (including 2.75-inch rockets) activities during 
training or testing within the San Diego Arc Mitigation Area, Naval 
units 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., explosives usage) in its annual activity reports submitted to 
NMFS.
    (5) Except as provided in paragraph (b)(2)(i)(A)(6) of this 
section, within the San Nicolas Island Mitigation Area, Navy personnel 
must not use explosives that could potentially result in the take of 
marine mammals during mine warfare, large-caliber gunnery, torpedo, 
bombing, and missile (including 2.75-inch rockets) activities during 
training.
    (6) Should national security require use of explosives that could 
potentially result in the take of marine mammals during mine warfare, 
large-caliber gunnery, torpedo, bombing, and missile (including 2.75-
inch rockets) activities during training in the San Nicolas Island 
Mitigation Area, Naval units 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., explosives usage) in its annual 
activity reports submitted to NMFS.
    (7) Except as provided in paragraph (b)(2)(i)(A)(8) of this 
section, within the Santa Monica/Long Beach Mitigation Area, Navy 
personnel must not use explosives that could potentially result in the 
take of marine mammals during mine warfare, large-caliber gunnery, 
torpedo, bombing, and missile (including 2.75-inch rockets) activities 
during training and testing.
    (8) Should national security require use of explosives that could 
potentially result in the take of marine mammals during mine warfare, 
large-caliber gunnery, torpedo, bombing, and missile (including 2.75-
inch rockets) activities during training or testing in the Santa 
Monica/Long Beach Mitigation Area, Naval units 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., explosives usage) in 
its annual activity reports submitted to NMFS.
    (B) Santa Barbara Island Mitigation Area (year-round). (1) Except 
as provided in paragraph (b)(2)(i)(B)(2) of this section, Navy 
personnel must not use MF1 surface ship hull-mounted mid-frequency 
active sonar during training or testing, or explosives that could 
potentially result in the take of marine mammals during medium-caliber 
or large-caliber gunnery, torpedo, bombing, and missile (including 
2.75-inch rockets) activities during training.
    (2) Should national security require use of MF1 surface ship hull-
mounted mid-frequency active sonar during training or testing, or 
explosives that could potentially result in the take of marine mammals 
during medium-caliber or large-caliber gunnery, torpedo, bombing, and 
missile (including 2.75-inch rockets) activities during training, Naval 
units 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 or explosives usage) in its annual activity reports 
submitted to NMFS.
    (C) Blue Whale (June-October), Gray Whale (November-March), and Fin 
Whale (November-May) Awareness Notification Message Areas. (1) Navy 
personnel must issue a seasonal awareness notification message to alert 
ships and aircraft operating in the area to the possible presence of 
concentrations of large whales, including blue whales, gray whales, and 
fin whales.
    (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 large whale species.
    (3) Platforms must 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.
    (ii) [Reserved]


Sec.  218.75  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.  218.70 is thought to have 
resulted in the mortality or serious injury of any marine mammals, or 
in any Level A harassment or Level B harassment take of marine mammals 
not identified in this subpart.
    (b) Monitoring and reporting under the LOAs. The Navy must conduct 
all monitoring and reporting required under the LOAs, including abiding 
by the HSTT Study Area monitoring program. 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. 
The Navy 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 www.fisheries.noaa.gov/national/marine-mammal-protection/incidentaltake-authorizations-military-readinessactivities.
    (d) Annual HSTT Study Area marine species monitoring report. The 
Navy must submit an annual report of the HSTT Study Area monitoring 
describing the implementation and results from the previous calendar 
year. Data collection methods must be standardized across range 
complexes and study areas 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. This report will describe progress of knowledge 
made with respect to intermediate scientific objectives within the HSTT 
Study Area associated with the Integrated Comprehensive Monitoring 
Program (ICMP). Similar study questions must be treated together so 
that progress on each topic can be summarized across all Navy ranges. 
The report need not include analyses and content that does not provide 
direct assessment of cumulative progress on the monitoring plan study 
questions. As an alternative, the Navy may submit a multi-Range Complex 
annual Monitoring Plan report to fulfill this requirement. 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 HSTT, Gulf of Alaska, Mariana 
Islands, and Northwest Study Areas.

[[Page 41903]]

    (e) Annual HSTT Study Area training exercise report and testing 
activity report. Each year, the Navy must submit two preliminary 
reports (Quick Look Report) detailing the status of authorized sound 
sources within 21 days after the anniversary of the date of issuance of 
each LOA to the Director, Office of Protected Resources, NMFS. Each 
year, the Navy must submit detailed reports to the Director, Office of 
Protected Resources, NMFS, within 3 months after the one-year 
anniversary of the date of issuance of the LOA. The HSTT annual 
Training Exercise Report and Testing Activity Report can be 
consolidated with other exercise reports from other range complexes in 
the Pacific Ocean for a single Pacific Exercise Report, if desired. The 
annual reports must contain information on major training exercises 
(MTEs), Sinking Exercise (SINKEX) events, and a summary of all sound 
sources used, including within specific mitigation reporting areas as 
described in paragraph (e)(3) of this section. The analysis in the 
detailed reports must be based on the accumulation of data from the 
current year's report and data collected from previous reports. The 
detailed reports must contain information identified in paragraphs 
(e)(1) through (7) of this section.
    (1) MTEs. This section of the report must contain the following 
information for MTEs conducted in the HSTT 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 the exercise.
    (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/dolphin/
pinniped).
    (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 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, dolphin, or 
pinniped).
    (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 acoustic sources (e.g., pile driving and air gun 
activities); and
    (ii) Total annual expended/detonated ordinance (missiles, bombs, 
sonobuoys, etc.) for each explosive bin.
    (4) Humpback Whale Special Reporting Area (December 15-April 15). 
The Navy must report the total hours of operation of surface ship hull-
mounted mid-frequency active sonar used in the special reporting area.
    (5) HSTT Study Area Mitigation Areas. The Navy must report any use 
that occurred as specifically described in these areas. Information 
included in the classified annual reports may be used to inform future 
adaptive management of activities within the HSTT Study Area.
    (6) Geographic information presentation. The reports must present 
an annual (and seasonal, where practical) depiction of training and 
testing bin usage (as well as pile driving activities) geographically 
across the HSTT Study Area.

[[Page 41904]]

    (7) 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) Seven-year close-out comprehensive training and testing 
activity report. This report must be included as part of the 2025 
annual training and testing report. This report must provide the annual 
totals for each sound source bin with a comparison to the annual 
allowance and the seven-year total for each sound source bin with a 
comparison to the seven-year allowance. Additionally, if there were any 
changes to the sound source allowance, this report must include a 
discussion of why the change was made and include the analysis to 
support how the change did or did not affect the analysis in the 2018 
HSTT FEIS/OEIS and MMPA final rule. The draft 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 3 months after the submittal of the draft 
if NMFS does not provide comments.


Sec.  218.76   Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to the regulations 
in this subpart, the Navy must apply for and obtain LOAs in accordance 
with Sec.  216.106 of this chapter.
    (b) LOAs, unless suspended or revoked, may be effective for a 
period of time not to exceed December 20, 2025.
    (c) If an LOA expires prior to December 20, 2025, 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.  218.77(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.  218.77.
    (e) Each LOA must 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., 
mitigation) on the species or stocks 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) must be published in 
the Federal Register within 30 days of a determination.


Sec.  218.77  Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec. Sec.  216.106 of this chapter and 
218.76 for the activity identified in Sec.  218.70(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 stock 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 chapter and 
218.76 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 monitoring from the previous year(s);
    (B) Results from other marine mammal and/or sound research or 
studies; or
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent, or number not authorized by 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 or stocks of 
marine mammals specified in LOAs issued pursuant to Sec. Sec.  216.106 
of this chapter and 218.76, an LOA may be modified without prior notice 
or opportunity for public comment. Notice would be published in the 
Federal Register within 30 days of the action.


Sec. Sec.  218.78-218.79  [Reserved]

[FR Doc. 2020-14181 Filed 7-9-20; 8:45 am]
BILLING CODE 3510-22-P