# 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

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URL: https://www.frixlaw.com/law-library/documents/fr%3A2019-18850

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** September 13, 2019
- **Citation:** 84 FR 48388

## Text

DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 218
[190826-0018 ]
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:

Proposed rule; request for comment.

SUMMARY:

NMFS has received a request from the U.S. Navy (Navy) to extend the time period from December 2023 to December 2025 for Marine Mammal Protection Act (MMPA) regulations authorizing the take of marine mammals incidental to Navy training and testing activities conducted in the Hawaii-Southern California Training and Testing (HSTT) Study Area. In August 2018, the MMPA was amended by the John S. McCain National Defense Authorization Act (NDAA) for Fiscal Year 2019 to allow for 7-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. In making the request to extend the time period covered by the MMPA HSTT regulations from five to seven years, the Navy proposes no changes to their specified activities, the geographical region in which those activities would be conducted, mitigation measures, monitoring, or reporting over the longer seven-year period. Pursuant to the MMPA, NMFS is requesting comments on the proposed seven-year rule and associated Letters of Authorization (LOAs) to cover the same activities covered by the existing 2018 HSTT regulations. NMFS will consider all public comments prior to issuing any final rule and making final decisions on the issuance of the requested LOAs, and agency responses will be summarized in the notice of the final decision.

DATES:

Comments and information must be received no later than October 15, 2019.

ADDRESSES:

You may submit comments on this document, identified by NOAA-NMFS-2019-0103, by any of the following methods:

•
Electronic submission:
Submit all electronic public comments via the federal e-Rulemaking Portal. Go to
www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2019-0103,
click the “Comment Now!” icon, complete the required fields, and enter or attach your comments.

•
Mail:
Submit written comments to Jolie Harrison, Chief, Permits and Conservation Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East West Highway, Silver Spring, MD 20910.

Instructions:
Comments sent by any other method, to any other address or individual, or received after the end of the comment period, may not be considered by NMFS. All comments received are a part of the public record and will generally be posted for public viewing on
www.regulations.gov
without change. All personal identifying information (
e.g.,
name, address), confidential business information, or otherwise sensitive information submitted voluntarily by the sender will be publicly accessible. NMFS will accept anonymous comments (enter “N/A” in the required fields if you wish to remain anonymous). Attachments to electronic comments will be accepted in Microsoft Word, Excel, or Adobe PDF file formats only.

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

FOR FURTHER INFORMATION CONTACT:

Wendy Piniak, Office of Protected Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Purpose of Regulatory Action

These proposed regulations, issued under the authority of the MMPA (16 U.S.C. 1361
et seq.
), would 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 on the high seas where sonar training and testing may occur.

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.

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, the public is provided with notice of the proposed incidental take authorization the opportunity to review and 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
Preliminary 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 it applies to a “military readiness activity” to read as follows (Section 3(18)(B) of the MMPA): (i) Any act that injures or has the significant potential to injure a marine mammal or marine mammal stock in the wild (Level A Harassment); or (ii) Any act that disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing disruption of natural behavioral patterns, including, but not limited to, migration, surfacing, nursing, breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned or significantly altered (Level B harassment). 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 issued 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 proposes no changes to the nature of the specified activities covered by the 2018 HSTT final rule, the level of activity within and between years would be consistent with that previously analyzed in the 2018 HSTT final rule, and all activities would 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 are 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 the same for seven years of identical activity.

The Navy's mission is to organize, train, equip, and maintain combat-ready naval forces capable of winning wars, deterring aggression, and maintaining freedom of the seas. This mission is mandated by federal law (10 U.S.C. 8062), which ensures the readiness of the naval forces of the United States. 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 proposes to continue conducting training and testing activities 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 would occur over seven years, including the five years already authorized under the 2018 HSTT regulations, with the regulations valid from the publication date of the final rule (if issued) through December 20, 2025.

Summary of the Proposed Regulations

NMFS is proposing to extend 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 only recently published and its analysis remains current and valid. In its 2019 application, the Navy proposes 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) would be identical to those described and analyzed in the 2018 HSTT final rule. The proposed regulatory language included at the end of this proposed rule, which would be published at 50 CFR part 218, subpart H, also is the same as that under the HSTT 2018 regulations, except for a small number of technical changes. No new information has been received from the 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 proposed rule relies heavily on and references to the applicable information and analyses

in those documents. Below is a list of the regulatory documents referenced in this proposed rule. The list indicates the short name by which the document is referenced in this proposed 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”);

• 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 requests 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. 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 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 (
http://www.hstteis.com/
). Each military training and testing activity described meets mandated Fleet requirements to deploy ready forces. The Navy proposes 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 proposed rule are identical to those described and analyzed in the 2018 HSTT final rule.

Dates and Duration

The specified activities would occur at any time during the seven-year period of validity of the regulations. The proposed number of training and testing activities are described in the
Detailed Description of the Specified Activities
section (Tables 1 through 9).

Specified Geographical Region

The Navy proposes no changes to the geographic extent of the HSTT Study Area as 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
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 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 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 submarines generally operate at speeds in the range of 8-13 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).

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 proposes 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 those 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 proposed 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 and analyzing potential impacts to marine mammals, the Navy proposes that the additional two years of training and testing would consist of one additional year of maximum training tempo and one representative year of training tempo consistent with the pattern set forth in the 2018 HSTT final rule, the 2018 HSTT FEIS/OEIS, and the 2017 Navy application.

Proposed Training Activities

The number of proposed 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 proposed 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 proposed 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—Proposed Training Activities Analyzed for Seven-Year Period in the HSTT Study Area

Stressor category
Activity name
Description
Source bin
Location

7-Year
number
of events

Major Training Events—Large Integrated Anti-Submarine Warfare

Acoustic

Composite Training Unit Exercise
1

Aircraft carrier and carrier air wing integrates with surface and submarine units in a challenging multi-threat operational environment that certifies them ready to deploy
ASW1, ASW2, ASW3, ASW4, ASW5, HF1, LF6, MF1, MF3, MF4, MF5, MF11, MF12
SOCAL
18

Acoustic

Rim of the Pacific Exercise
1

A biennial multinational training exercise in which navies from Pacific Rim nations and the United Kingdom assemble in Pearl 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
ASW2, ASW3, ASW4, HF1, HF3, HF4, M3, MF1, MF3, MF4, MF5, MF11

HRC
SOCAL

4
4

Major Training Events—Medium Integrated Anti-Submarine Warfare

Acoustic

Fleet Exercise/Sustainment Exercise
1

Aircraft carrier and carrier air wing integrates with surface and submarine units in a challenging multi-threat operational environment to maintain ability to deploy
ASW1, ASW2, ASW3, ASW4, HF1, LF6, MF1, MF3, MF4, MF5, MF11, MF12

HRC
SOCAL

7
35

Acoustic
Undersea Warfare Exercise
Elements of the anti-submarine warfare tracking exercise combine in this exercise of multiple air, surface, and subsurface units, over a period of several days. Sonobuoys are released from aircraft. Active and passive sonar used
ASW3, ASW4, HF1, LF6, MF1, MF3, MF4, MF5, MF11, MF12
HRC
17

Integrated/Coordinated Training—Small Integrated Anti-Submarine Warfare Training

Acoustic
Navy Undersea Warfare Training and Assessment Course Surface Warfare Advanced Tactical Training
Multiple ships, aircraft, and submarines integrate the use of their sensors to search for, detect, classify, localize, and track a threat submarine in order to launch an exercise torpedo
ASW3, ASW4, HF1, MF1, MF3, MF4, MF5

HRC
SOCAL

7
18

Integrated/Coordinated Training—Medium Coordinated Anti-Submarine Warfare Training

Acoustic
Submarine Commanders Course
Train prospective submarine Commanding Officers to operate against surface, air, and subsurface threats
ASW3, ASW4, HF1, MF1, MF3, MF4, MF5, TORP1, TORP2

HRC
SOCAL

12
12

Integrated/Coordinated Training—Small Coordinated Anti-Submarine Warfare Training

Acoustic
Amphibious Ready Group/Marine Expeditionary Unit Exercise Group Sail Independent Deployer Certification Exercise/Tailored Anti-Submarine Warfare Training
Small-scale, short duration, coordinated anti-submarine warfare exercises
ASW2, ASW3, ASW4, HF1, MF1, MF3, MF4, MF5, MF11

HRC
SOCAL

14
86

Amphibious Warfare

Explosive
Naval Surface Fire Support Exercise—at Sea
Surface ship uses large-caliber gun to support forces ashore; however, land target simulated at sea. Rounds impact water and are scored by passive acoustic hydrophones located at or near target area
Large-caliber HE rounds (E5)
HRC (W188)
105

Acoustic
Amphibious Marine Expeditionary Unit Exercise
Navy and Marine Corps forces conduct advanced integration training in preparation for deployment certification
ASW2, ASW3, ASW4, HF1, MF1, MF3, MF4, MF5, MF11
SOCAL
18

Acoustic
Amphibious Marine Expeditionary Unit Integration Exercise
Navy and Marine Corps forces conduct integration training at sea in preparation for deployment certification
ASW2, ASW3, ASW4, HF1, MF1, MF3, MF4, MF5, MF11
SOCAL
18

Acoustic
Marine Expeditionary Unit Composite Training Unit Exercise
Amphibious Ready Group exercises are conducted to validate the Marine Expeditionary Unit's 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
ASW2, ASW3, ASW4, HF1, MF1, MF3, MF4, MF5, MF11
SOCAL
18

Anti-Submarine Warfare

Acoustic
Anti-Submarine Warfare Torpedo Exercise—Helicopter
Helicopter crews search for, track, and detect submarines. Recoverable air launched torpedoes are employed against submarine targets
MF4, MF5, TORP1

HRC
SOCAL

42
728

Acoustic
Anti-Submarine Warfare Torpedo Exercise—Maritime Patrol Aircraft
Maritime patrol aircraft crews search for, track, and detect submarines. Recoverable air launched torpedoes are employed against submarine targets
MF5, TORP1

HRC
SOCAL

70
175

Acoustic
Anti-Submarine Warfare Torpedo Exercise—Ship
Surface ship crews search for, track, and detect submarines. Exercise torpedoes are used during this event
ASW3, MF1, TORP1

HRC
SOCAL

350
819

Acoustic
Anti-Submarine Warfare Torpedo Exercise—Submarine
Submarine crews search for, track, and detect submarines. Exercise torpedoes are used during this event
ASW4, HF1, MF3, TORP2

HRC
SOCAL

336
91

Acoustic
Anti-Submarine Warfare Tracking Exercise—Helicopter
Helicopter crews search for, track, and detect submarines
MF4, MF5

HRC
SOCAL, PMSR
HSTT Transit Corridor

1,113
3,668
42

Acoustic
Anti-Submarine Warfare Tracking Exercise—Maritime Patrol Aircraft
Maritime patrol aircraft aircrews search for, track, and detect submarines. Recoverable air launched torpedoes are employed against submarine targets
MF5

HRC
SOCAL, PMSR

182
350

Acoustic
Anti-Submarine Warfare Tracking Exercise—Ship
Surface ship crews search for, track, and detect submarines
ASW3, MF1, MF11, MF12

HRC
SOCAL, PMSR

1,568
2,961

Acoustic
Anti-Submarine Warfare Tracking Exercise—Submarine
Submarine crews search for, track, and detect submarines
ASW4, HF1, HF3, MF3

HRC
SOCAL, PMSR
HSTT Transit Corridor

1,400
350
49

Explosive, Acoustic
Service Weapons Test
Air, surface, or submarine crews employ explosive torpedoes against virtual targets
HF1, MF3, MF6, TORP2, Explosive torpedoes (E11)

HRC
SOCAL

14
7

Mine Warfare

Acoustic
Airborne Mine Countermeasure—Mine Detection
Helicopter aircrews detect mines using towed or laser mine detection systems
HF4
SOCAL
70

Explosive, Acoustic
Civilian Port Defense—Homeland Security Anti-Terrorism/Force Protection Exercises
Maritime security personnel train to protect civilian ports against enemy efforts to interfere with access to those ports
HF4, SAS2, E2, E4

Pearl Harbor, HI
San Diego, CA

7
21

Explosive
Marine Mammal Systems

The Navy deploys trained bottlenose dolphins (
Tursiops truncatus
) and California sea lions (
Zalophus californianus
) as part of the marine mammal mine-hunting and object-recovery system

E7

HRC
SOCAL

70
1,225

Acoustic
Mine Countermeasure Exercise—Ship Sonar
Ship crews detect and avoid mines while navigating restricted areas or channels using active sonar
HF4, HF8, MF1K

HRC
SOCAL

210
664

Acoustic
Mine Countermeasure Exercise—Surface
Mine countermeasure ship crews detect, locate, identify, and avoid mines while navigating restricted areas or channels, such as while entering or leaving port
HF4
SOCAL
1,862

Explosive, Acoustic
Mine Countermeasures Mine Neutralization Remotely Operated Vehicle
Ship, small boat, and helicopter crews locate and disable mines using remotely operated underwater vehicles
HF4, E4

HRC
SOCAL

42
2,604

Explosive
Mine Neutralization Explosive Ordnance Disposal
Personnel disable threat mines using explosive charges
E4, E5, E6, E7

HRC (Puuloa)
SOCAL (IB, TAR 2, TAR 3, TAR 21, SWAT 3, SOAR)

140
1,358

Acoustic
Submarine Mine Exercise
Submarine crews practice detecting mines in a designated area
HF1

HRC
SOCAL

280
84

Acoustic
Surface Ship Object Detection
Ship crews detect and avoid mines while navigating restricted areas or channels using active sonar
MF1K, HF8

HRC
SOCAL

287
1,134

Explosive
Underwater Demolitions Multiple Charge—Mat Weave and Obstacle Loading
Military personnel use explosive charges to destroy barriers or obstacles to amphibious vehicle access to beach areas
E10, E13
SOCAL (TAR 2, TAR 3)
126

Explosive
Underwater Demolition Qualification and Certification
Navy divers conduct various levels of training and certification in placing underwater demolition charges
E6, E7

HRC (Puuloa)
SOCAL (TAR 2)

203
700

Surface Warfare

Explosive
Bombing Exercise Air-to-Surface
Fixed-wing aircrews deliver bombs against surface targets

E12
2

HRC
SOCAL
HSTT Transit Corridor

1309
4480
35

Explosive
Gunnery Exercise Surface-to-Surface Boat Medium-Caliber
Small boat crews fire medium-caliber guns at surface targets
E1, E2

HRC
SOCAL

70
98

Explosive
Gunnery Exercise Surface-to-Surface Ship Large-caliber
Surface ship crews fire large-caliber guns at surface targets
E5

HRC
SOCAL
HSTT Transit Corridor

210
1,302
91

Explosive
Gunnery Exercise Surface-to-Surface Ship Medium-Caliber
Surface ship crews fire medium-caliber guns at surface targets
E1, E2

HRC
SOCAL
HSTT Transit Corridor

350
1,260
280

Explosive, Acoustic
Independent Deployer Certification Exercise/Tailored Surface Warfare Training
Multiple ships, aircraft and submarines conduct integrated multi-warfare training with a surface warfare emphasis. Serves as a ready-to-deploy certification for individual surface ships tasked with surface warfare missions
E1, E3, E6, E10
SOCAL
7

Explosive
Integrated Live Fire Exercise
Naval Forces defend against a swarm of surface threats (ships or small boats) with bombs, missiles, rockets, and small-, medium- and large-caliber guns
E1, E3, E6, E10

HRC (W188A)
SOCAL (SOAR)

7
7

Explosive
Missile Exercise Air-to-Surface
Fixed-wing and helicopter aircrews fire air-to-surface missiles at surface targets
E6, E8, E10

HRC
SOCAL

70
1,498

Explosive
Missile Exercise Air-to-Surface Rocket
Helicopter aircrews fire both precision-guided and unguided rockets at surface targets
E3

HRC
SOCAL

1,598
1,722

Explosive
Missile Exercise Surface-to-Surface
Surface ship crews defend against surface threats (ships or small boats) and engage them with missiles
E6, E10

HRC (W188)
SOCAL (W291)

140
70

Explosive, Acoustic
Sinking Exercise
Aircraft, ship, and submarine crews deliberately sink a seaborne target, usually a decommissioned ship made environmentally safe for sinking according to U.S. Environmental Protection Agency standards, with a variety of munitions
TORP2, E5, E10, E12

HRC
SOCAL

21
4

Pile driving
Elevated Causeway System
A pier is constructed off of the beach. Piles are driven into the bottom with an impact hammer. Piles are removed from seabed via vibratory extractor. Only in-water impacts are analyzed
Impact hammer or vibratory extractor
SOCAL
14

Other Training Exercises

Acoustic
Kilo Dip
Functional check of the dipping sonar prior to conducting a full test or training event on the dipping sonar
MF4

HRC
SOCAL

420
16,800

Acoustic
Submarine Navigation Exercise
Submarine crews operate sonar for navigation and object detection while transiting into and out of port during reduced visibility
HF1, MF3

Pearl Harbor, HI
San Diego Bay, CA

1,540
560

Acoustic
Submarine Sonar Maintenance and Systems Checks
Maintenance of submarine sonar systems is conducted pierside or at sea
MF3

HRC
Pearl Harbor, HI
SOCAL
San Diego Bay, CA
HSTT Transit Corridor

1,820
1,820
651
644
70

Acoustic
Submarine Under-Ice Certification
Submarine crews train to operate under ice. Ice conditions are simulated during training and certification events
HF1

HRC
SOCAL

84
42

Acoustic
Surface Ship Sonar Maintenance and Systems Checks
Maintenance of surface ship sonar systems is conducted pierside or at sea
HF8, MF1

HRC
Pearl Harbor, HI
SOCAL
San Diego, CA
HSTT Transit Corridor

525
560
1,750
1,750
56

Acoustic
Unmanned Underwater Vehicle Training—Certification and Development
Unmanned underwater vehicle certification involves training with unmanned platforms to ensure submarine crew proficiency. Tactical development involves training with various payloads for multiple purposes to ensure that the systems can be employed effectively in an operational environment
FLS2, M3, SAS2

HRC
SOCAL

175
70

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.

Proposed Testing Activities

The number of proposed 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 proposed 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 proposed testing activities that could occur for the seven-year period are presented in Tables 2 through 5.

Naval Air Systems Command

The proposed 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—Proposed Naval Air Systems Command Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area

Stressor category
Activity name
Description
Source bin
Location

7-Year
number
of events

Anti-Submarine Warfare

Acoustic
Anti-Submarine Warfare Torpedo Test
This event is similar to the training event torpedo exercise. Test evaluates anti-submarine warfare systems onboard rotary-wing and fixed-wing aircraft and the ability to search for, detect, classify, localize, track, and attack a submarine or similar target
MF5, TORP1

HRC
SOCAL

134
353

Explosive, Acoustic
Anti-Submarine Warfare Tracking Test—Helicopter
This event is similar to the training event anti-submarine tracking exercise—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
MF4, MF5, E3
SOCAL
414

Explosive, Acoustic
Anti-Submarine Warfare Tracking Test—Maritime Patrol Aircraft
The test evaluates the sensors and systems used by maritime patrol aircraft to detect and track submarines and to ensure that aircraft systems used to deploy the tracking systems perform to specifications and meet operational requirements
ASW2, ASW5, MF5, MF6, E1, E3

HRC
SOCAL

399
436

Explosive, Acoustic
Sonobuoy Lot Acceptance Test
Sonobuoys are deployed from surface vessels and aircraft to verify the integrity and performance of a lot or group of sonobuoys in advance of delivery to the fleet for operational use
ASW2, ASW5, HF5, HF6, LF4, MF5, MF6, E1, E3, E4
SOCAL
1,120

Mine Warfare

Acoustic
Airborne Dipping Sonar Minehunting Test
A mine-hunting dipping sonar system that is deployed from a helicopter and uses high-frequency sonar for the detection and classification of bottom and moored mines
HF4
SOCAL
24

Explosive
Airborne Mine Neutralization System Test

A test of the airborne mine neutralization system that 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

E4
SOCAL
117

Acoustic
Airborne Sonobuoy Minehunting Test
A mine-hunting system made up of sonobuoys deployed from a helicopter. A field of sonobuoys, using high-frequency sonar, is used for detection and classification of bottom and moored mines
HF6
SOCAL
33

Surface Warfare

Explosive
Air-to-Surface Bombing Test
This event is similar to the training event bombing 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
E9

HRC
SOCAL

56
98

Explosive
Air-to-Surface Gunnery Test
This event is similar to the training event gunnery 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
E1

HRC
SOCAL

35
330

Explosive
Air-to-Surface Missile Test
This event is similar to the training event missile 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
E6, E9, E10

HRC
SOCAL

126
384

Explosive
Rocket Test
Rocket tests are conducted to evaluate the integration, 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
E3

HRC
SOCAL

14
142

Other Testing Activities

Acoustic
Kilo Dip

Functional check of a helicopter deployed dipping sonar system (
e.g.,
AN/AQS-22) prior to conducting a testing or training event using the dipping sonar system

MF4
SOCAL
12

Acoustic
Undersea Range System Test
Post installation node survey and test and periodic testing of range node transmit functionality
MF9
HRC
129

Notes:
HRC = Hawaii Range Complex, SOCAL = Southern California Range Complex.

Naval Sea Systems Command

The proposed 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—Proposed Naval Sea Systems Command Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area

Stressor category
Activity name
Description
Source bin
Location

7-Year
number of events

Anti-Submarine Warfare

Acoustic
Anti-Submarine Warfare Mission Package Testing

Ships and their supporting platforms (
e.g.,
rotary-wing aircraft and unmanned aerial systems) detect, localize, and prosecute submarines

ASW1, ASW2, ASW3, ASW5, MF1, MF4, MF5, MF12, TORP1

HRC
SOCAL

154
161

Acoustic
At-Sea Sonar Testing
At-sea testing to ensure systems are fully functional in an open ocean environment
ASW3, ASW4, HF1, LF4, LF5, M3, MF1, MF1K, MF2, MF3, MF5, MF9, MF10, MF11

HRC
HRC-SOCAL
SOCAL

109
7
138

Acoustic
Countermeasure Testing
Countermeasure testing involves the testing of systems that will detect, localize, and track incoming weapons, including marine vessel targets. Testing includes surface ship torpedo defense systems and marine vessel stopping payloads
ASW3, ASW4, HF5, TORP1, TORP2

HRC
HRC-SOCAL
SOCAL
HSTT Transit Corridor

56
28
77
14

Acoustic
Pierside Sonar Testing
Pierside testing to ensure systems are fully functional in a controlled pierside environment prior to at-sea test activities
HF1, HF3, HF8, M3, MF1, MF3, MF9

Pearl Harbor, HI
San Diego, CA

49
49

Acoustic
Submarine Sonar Testing/Maintenance
Pierside and at-sea testing of submarine systems occurs periodically following major maintenance periods and for routine maintenance
HF1, HF3, M3, MF3

HRC
Pearl Harbor, HI
San Diego, CA

28
119
168

Acoustic
Surface Ship Sonar Testing/Maintenance
Pierside and at-sea testing of ship systems occurs periodically following major maintenance periods and for routine maintenance
ASW3, MF1, MF1K, MF9, MF10

HRC
Pearl Harbor, HI
San Diego, CA
SOCAL

21
21
21
21

Explosive, Acoustic
Torpedo (Explosive) Testing
Air, surface, or submarine crews employ explosive and non-explosive torpedoes against artificial targets
ASW3, HF1, HF5, HF6, MF1, MF3, MF4, MF5, MF6, TORP1, TORP2, E8, E11

HRC (W188)
HRC (W188) SOCAL
SOCAL

56
21
56

Acoustic
Torpedo (Non-Explosive) Testing
Air, surface, or submarine crews employ non-explosive torpedoes against submarines or surface vessels
ASW3, ASW4, HF1, HF6, M3, MF1, MF3, MF4, MF5, MF6, TORP1, TORP2, TORP3

HRC
HRC SOCAL
SOCAL

56
63
56

Mine Warfare

Explosive, Acoustic
Mine Countermeasure and Neutralization Testing
Air, surface, and subsurface vessels neutralize threat mines and mine-like objects
HF4, E4
SOCAL
70

Explosive, Acoustic
Mine Countermeasure Mission Package Testing
Vessels and associated aircraft conduct mine countermeasure operations
HF4, SAS2, E4

HRC
SOCAL

118
406

Acoustic
Mine Detection and Classification Testing
Air, surface, and subsurface vessels detect and classify mines and mine-like objects. Vessels also assess their potential susceptibility to mines and mine-like objects
HF1, HF8, MF1, MF5

HRC
HRC SOCAL
SOCAL

14
10
77

Surface Warfare

Explosive
Gun Testing—Large-Caliber
Surface crews defend against surface targets with large-caliber guns
E3

HRC
HRC-SOCAL
SOCAL

49
504
49

Explosive
Gun Testing—Medium-Caliber
Surface crews defend against surface targets with medium-caliber guns
E1

HRC
HRC-SOCAL
SOCAL

28
336
28

Explosive
Missile and Rocket Testing
Missile and rocket testing includes various missiles or rockets fired from submarines and surface combatants. Testing of the launching system and ship defense is performed
E6

HRC
HRC-SOCAL
SOCAL

91
168
140

Unmanned Systems

Acoustic
Unmanned Surface Vehicle System Testing
Testing involves the production or upgrade of unmanned surface vehicles. This may include tests of mine detection capabilities, evaluations of the basic functions of individual platforms, or complex events with multiple vehicles
HF4, SAS2

HRC
SOCAL

21
28

Acoustic
Unmanned Underwater Vehicle Testing
Testing involves the production or upgrade of unmanned underwater vehicles. This may include tests of mine detection capabilities, evaluations of the basic functions of individual platforms, or complex events with multiple vehicles
HF4, MF9

HRC
SOCAL

21
2,037

Vessel Evaluation

Acoustic
Submarine Sea Trials-Weapons System Testing
Submarine weapons and sonar systems are tested at-sea to meet the integrated combat system certification requirements
HF1, M3, MF3, MF9, MF10, TORP2

HRC
SOCAL

7
7

Explosive
Surface Warfare Testing
Tests the capabilities of shipboard sensors to detect, track, and engage surface 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)
E1, E5, E8

HRC
HRC-SOCAL
SOCAL

63
441
102

Acoustic
Undersea Warfare Testing
Ships demonstrate capability of countermeasure systems and underwater surveillance, weapons engagement, and communications systems. This tests ships ability to detect, track, and engage undersea targets
ASW4, HF4, HF8, MF1, MF4, MF5, MF6, TORP1, TORP2

HRC
HRC SOCAL
SOCAL

49
60
69

Acoustic
Vessel Signature Evaluation
Surface ship, submarine and auxiliary system signature assessments. This may include electronic, radar, acoustic, infrared and magnetic signatures
ASW3

HRC
HRC SOCAL
SOCAL

28
252
168

Other Testing Activities

Acoustic
Insertion/Extraction
Testing of submersibles capable of inserting and extracting personnel and payloads into denied areas from strategic distances
M3, MF9

HRC
SOCAL

7
7

Acoustic
Signature Analysis Operations
Surface ship and submarine testing of electromagnetic, acoustic, optical, and radar signature measurements
HF1, M3, MF9

HRC
SOCAL

14
7

Notes:
HRC = Hawaii Range Complex, SOCAL = Southern California Range Complex, HSTT = Hawaii-Southern California Training and Testing, CA = California, HI = Hawaii.

Office of Naval Research

The proposed 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—Proposed Office of Naval Research Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area

Stressor category
Activity name
Description
Source bin
Location

7-Year
number of events

Acoustic and Oceanographic Science and Technology

Explosive, Acoustic
Acoustic and Oceanographic Research
Research using active transmissions from sources deployed from ships and unmanned underwater vehicles. Research sources can be used as proxies for current and future Navy systems
AG, ASW2, BB4, BB9, LF3, LF4, LF5, MF8, MF9, MF9, MF9, E3

HRC
SOCAL

14
28

Acoustic
Long Range Acoustic Communications
Bottom mounted acoustic source off of the Hawaiian Island of Kauai will transmit a variety of acoustic communications sequences
LF4
HRC
21

Notes:
HRC = Hawaii Range Complex, SOCAL = Southern California Range Complex.

Naval Information Warfare Systems Command

The proposed 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—Proposed Naval Information Warfare Systems Command Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area

Stressor category
Activity name
Description
Source bin
Location

7-Year
number of events

Acoustic
Anti-Terrorism/Force Protection
Testing sensor systems that can detect threats to naval piers, ships, and shore infrastructure
SD1

San Diego, CA
SOCAL

98
112

Acoustic
Communications
Testing of underwater communications and networks to extend the principles of FORCEnet below the ocean surface
ASW2, ASW5, HF6, LF4

HRC
SOCAL

5
70

Acoustic
Energy and Intelligence, Surveillance, and Reconnaissance Sensor Systems
Develop, integrate, and demonstrate Intelligence, Surveillance, and Reconnaissance systems and in-situ energy systems to support deployed systems
AG, HF2, HF7, LF4, LF5, LF6, MF10

HRC
SOCAL
HSTT Transit Corridor

87
357
56

Acoustic
Vehicle Testing
Testing of surface and subsurface vehicles and sensor systems that may involve Unmanned Underwater Vehicles, gliders, and Unmanned Surface Vehicles
BB4, FLS2, FLS3, HF6, LF3, M3, MF9, MF13, SAS1, SAS2, SAS3

HRC
SOCAL
HSTT Transit Corridor

8
1,141
14

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 proposed 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 proposed 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 proposes 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 proposed training and testing activities. Acoustic source bin use in the proposed activities would vary annually. The seven-year totals for the proposed 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

Source class category
Bin
Description

Unit
1

Training
7-year total
Testing
7-year total

Low-Frequency (LF): Sources that produce signals less than 1 kHz

LF3
LF4

LF sources greater than 200 dB
LF sources equal to 180 dB and up to 200 dB

H
H
C

0
0
0

1,365
4,496
140

LF5
LF sources less than 180 dB
H
65
14,458

LF6
LF sources greater than 200 dB with long pulse lengths
H
956
360

Mid-Frequency (MF): Tactical and non-tactical sources that produce signals between 1 and 10 kHz
MF1

Hull-mounted surface ship sonars (
e.g.,
AN/SQS-53C and AN/SQS-61)

H
38,489
8,692

MF1K
Kingfisher mode associated with MF1 sonars
H
700
98

MF2
2

Hull-mounted surface ship sonars (
e.g.,
AN/SQS-56)

H
0
378

MF3

Hull-mounted submarine sonars (
e.g.,
AN/BQQ-10)

H
14,700
9,177

MF4

Helicopter-deployed dipping sonars (
e.g.,
AN/AQS-22 and AN/AQS-13)

H
2,719
2,502

MF5

Active acoustic sonobuoys (
e.g.,
DICASS)

C
40,128
38,233

MF6

Active underwater sound signal devices (
e.g.,
MK 84)

C
63
8,202

MF8
Active sources (greater than 200 dB) not otherwise binned
H
0
490

MF9
Active sources (equal to 180 dB and up to 200 dB) not otherwise binned
H
0
36,056

MF10
Active sources (greater than 160 dB, but less than 180 dB) not otherwise binned
H
0
13,104

MF11
Hull-mounted surface ship sonars with an active duty cycle greater than 80%
H
5,205
392

MF12
Towed array surface ship sonars with an active duty cycle greater than 80%
H
1,260
4,620

MF13
MF sonar source
H
0
2,100

High-Frequency (HF): Tactical and non-tactical sources that produce signals between 10 and 100 kHz

HF1

HF2

Hull-mounted submarine sonars (
e.g.,
AN/BQQ-10)
HF Marine Mammal Monitoring System

H

H

12,550

0

5,403

840

HF3
Other hull-mounted submarine sonars (classified)
H
1,919
769

HF4

Mine detection, classification, and neutralization sonar (
e.g.,
AN/SQS-20)

H
15,012
114,069

HF5
Active sources (greater than 200 dB) not otherwise binned

H
C

0
0

6,720
280

HF6
Active sources (equal to 180 dB and up to 200 dB) not otherwise binned
H
0
7,015

HF7
Active sources (greater than 160 dB, but less than 180 dB) not otherwise binned
H
0
9,660

HF8

Hull-mounted surface ship sonars (
e.g.,
AN/SQS-61)

H
711
5,136

Anti-Submarine Warfare (ASW): Tactical sources (
e.g.,
active sonobuoys and acoustic countermeasures systems) used during ASW training and testing activities

ASW1
ASW2

ASW3

MF systems operating above 200 dB

MF Multistatic Active Coherent sonobuoy (
e.g.,
AN/SSQ-125)

MF towed active acoustic countermeasure systems (
e.g.,
AN/SLQ-25)

H
C

H

1,503
4,824

37,385

3,290
32,900

19,187

ASW4

MF expendable active acoustic device countermeasures (
e.g..,
MK 3)

C
9,023
15,398

ASW5
3

MF sonobuoys with high duty cycles
H
1,780
3,854

Torpedoes (TORP): Source classes associated with the active acoustic signals produced by torpedoes

TORP1

TORP2
TORP3

Lightweight torpedo (
e.g.,
MK 46, MK 54, or Anti-Torpedo Torpedo)

Heavyweight torpedo (
e.g.,
MK 48)

C

C
C

1,605

3,515
0

6,454

2,756
315

Forward Looking Sonar (FLS): Forward or upward looking object avoidance sonars used for ship navigation and safety

FLS2

FLS3

HF sources with short pulse lengths, narrow beam widths, and focused beam patterns
VHF sources with short pulse lengths, narrow beam widths, and focused beam patterns

H

H

196

0

3,424

18,480

Acoustic Modems (M): Systems used to transmit data through the water
M3
MF acoustic modems (greater than 190 dB)
H
274
3,623

Swimmer Detection Sonars (SD): Systems used to detect divers and submerged swimmers
SD1-SD2
HF and VHF sources with short pulse lengths, used for the detection of swimmers and other objects for the purpose of port security
H
0
70

Synthetic Aperture Sonars (SAS): Sonars in which active acoustic signals are post-processed to form high-resolution images of the seafloor

SAS1
SAS2
SAS3
SAS4

MF SAS systems
HF SAS systems
VHF SAS systems
MF to HF broadband mine countermeasure sonar

H
H
H
H

0
6,297
0
294

13,720
60,088
32,200
0

Broadband Sound Sources (BB): Sonar systems with large frequency spectra, used for various purposes

BB4
BB7
BB9

LF to MF oceanographic source
LF oceanographic source
MF optoacoustic source

H
C
H

0
0
0

6,414
196
3,360

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 proposed training and testing activities.

Table 7—Training and Testing Air Gun Sources Quantitatively Analyzed in the HSTT Study Area

Source class category
Bin

Unit
1

Training
7-year total
Testing
7-year total

Air Guns (AG): small underwater air guns
AG
C
0
5,908

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 would 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

Method
Piles per 24-hour period

Time per pile
(minutes)

Total estimated time of noise per 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 proposed training and testing activities take into account that annual variability.

Table 9—Explosive Source Bins Analyzed and Number Used for Seven-Year Period for Training and Testing Activities Within the HSTT Study Area

Bin

Net explosive weight

(lb.)
1

Example explosive source

Modeled
underwater detonation depths
(ft.)

Training
7-year total
Testing
7-year total

E1
0.1-0.25
Medium-caliber projectiles
0.3, 60
20,580
87,012

E2
>0.25-0.5
Medium-caliber projectiles
0.3, 50
12,222
0

E3
>0.5-2.5
Large-caliber projectiles
0.3, 60
19,579
20,848

E4
>2.5-5
Mine neutralization charge
10, 16, 33, 50, 61, 65, 650
266
4,372

E5
>5-10
5 in. projectiles
0.3, 10, 50
33,310
9,800

E6
>10-20
Hellfire missile
0.3, 10, 50, 60
4,056
230

E7
>20-60
Demo block/shaped charge
10, 50, 60
91
0

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 charges

NA
2

63
0

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 would 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 would 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 Navy proposes no changes to the manner in which Navy vessels would be used during training and testing activities, the speeds at which they operate, the number of vessels that would be used during various activities, or the locations in which Navy vessel movement would be concentrated within the HSTT Study Area 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 proposed 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 Navy proposes no changes to the Standard Operating Procedures from those included in the 2018 HSTT final rule.

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. Consistent with the 2018 HSTT final rule, the Navy still anticipates the take of individuals from 38 marine mammal species 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 (ESA) in the HSTT Study Area.

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 additional 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. NMFS has reviewed the most recent 2018 final Stock Assessment Reports (SARs); information on relevant UMEs; and other scientific literature, 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

Common name
Scientific name
Stock
Status
MMPA
ESA
Occurrence
Seasonal absence

Stock
abundance
(CV)/minimum
population

Blue whale
Balaenoptera musculus
Eastern North Pacific
Strategic, Depleted
Endangered
Southern California

1,647 (0.07)/1,551.

Central North Pacific
Strategic, Depleted
Endangered
Hawaii
Summer
133 (1.09)/63.

Bryde's whale
Balaenoptera brydei/edeni
Eastern Tropical Pacific

Southern California

unknown.

Hawaii

Hawaii

1,751 (0.29)/1,378.

Fin whale
Balaenoptera physalus
CA/OR/WA
Strategic, Depleted
Endangered
Southern California

9,029 (0.12)/8,127.

Hawaii
Strategic, Depleted
Endangered
Hawaii
Summer
154 (1.05)/75.

Gray whale
Eschrichtius robustus
Eastern North Pacific

Southern California

26,960 (0.05)/25,849.

Western North Pacific
Strategic, Depleted
Endangered
Southern California

290 (NA)/271.

Humpback whale
Megaptera novaeangliae
CA/OR/WA
Strategic, Depleted

Threatened/ Endangered
1

Southern California

2,900 (0.05)/2,784.

Central North Pacific
Strategic

Hawaii
Summer
10,103 (0.30)/7,891.

Minke whale
Balaenoptera acutorostrata
CA/OR/WA

Southern California

636 (0.72)/369.

Hawaii

Hawaii
Summer
unknown.

Sei whale
Balaenoptera borealis
Eastern North Pacific
Strategic, Depleted
Endangered
Southern California

519 (0.40)/374.

Hawaii
Strategic, Depleted
Endangered
Hawaii
Summer
391 (0.90)/204.

Sperm whale
Physeter macrocephalus
CA/OR/WA
Strategic, Depleted
Endangered
Southern California

1,997 (0.57)/1,270.

Hawaii
Strategic, Depleted
Endangered
Hawaii

4,559 (0.33)/3,478.

Pygmy sperm whale
Kogia breviceps
CA/OR/WA

Southern California
Winter and Fall
4,111 (1.12)/1,924.

Hawaii

Hawaii

unknown.

Dwarf sperm whale
Kogia sima
CA/OR/WA

Southern California

unknown.

Hawaii

Hawaii

unknown.

Baird's beaked whale
Berardius bairdii
CA/OR/WA

Southern California

2,697 (0.60)/1,633.

Blainville's beaked whale
Mesoplodon densirostris
Hawaii

Hawaii

2,105 (1.13)/980.

Cuvier's beaked whale
Ziphius cavirostris
CA/OR/WA

Southern California

3,274 (0.67)/2,059.

Hawaii

Hawaii

723 0.69/428.

Longman's beaked whale
Indopacetus pacificus
Hawaii

Hawaii

7,619 (0.66)/4,592.

Mesoplodon beaked whales
Mesoplodon spp.
CA/OR/WA

Southern California

3,044 (0.54)/1,967.

Common Bottlenose dolphin
Tursiops truncatus
California Coastal

Southern California

453 (0.06)/346.

CA/OR/WA Offshore

Southern California

1,924 (0.54)/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 crassidens
Main Hawaiian Islands Insular
Strategic, Depleted
Endangered
Hawaii

167 (0.14)/149.

Hawaii Pelagic

Hawaii

1,540 (0.66)/928.

Northwestern Hawaiian Islands

Hawaii

617 (1.11)/290.

Fraser's dolphin
Lagenodelphis hosei
Hawaii

Hawaii

51,491 (0.66)/31,034.

Killer whale
Orcinus orca
Eastern North Pacific Offshore

Southern California

300 (0.1)/276.

Eastern North Pacific Transient/West Coast Transient
2

Southern California

243 unknown/243.

Hawaii

Hawaii

146 (0.96)/74.

Long-beaked common dolphin
Delphinus capensis
California

Southern California

101,305 (0.49)/68,432.

Melon-headed whale
Peponocephala electra
Hawaiian Islands

Hawaii

8,666 (1.00)/4,299.

Kohala Resident

Hawaii

447 (0.12)/404.

Northern right whale dolphin
Lissodelphis borealis
CA/OR/WA

Southern California

26,556 (0.44)/18,608.

Pacific white-sided dolphin
Lagenorhynchus obliquidens
CA/OR/WA

Southern California

26,814 (0.28)/21,195.

Pantropical spotted dolphin
Stenella attenuata
Oahu

Hawaii

unknown.

4-Islands

Hawaii

unknown.

Hawaii Island

Hawaii

unknown.

Hawaii Pelagic

Hawaii

55,795 (0.40)/40,338.

Pygmy killer whale
Feresa attenuata
Tropical

Southern California
Winter & Spring
unknown.

Hawaii

Hawaii

10,640 (0.53)/6,998.

Risso's dolphins
Grampus griseus
CA/OR/WA

Southern California

6,336 (0.32)/4,817.

Hawaii

Hawaii

11,613 (0.43)/8,210.

Rough-toothed dolphin
Steno bredanensis

NSD
3

Southern California

unknown.

Hawaii

Hawaii

72,528 (0.39)/52,833.

Short-beaked common dolphin
Delphinus delphis
CA/OR/WA

Southern California

969,861 (0.17)/839,325.

Short-finned pilot whale
Globicephala macrorhynchus
CA/OR/WA

Southern California

836 (0.79)/466.

Hawaii

Hawaii

19,503 (0.49)/13,197.

Spinner dolphin
Stenella longirostris
Hawaii Pelagic

Hawaii

unknown.

Hawaii Island

Hawaii

665 (0.09)/617.

Oahu and 4-Islands

Hawaii

NA.

Kauai and Niihau

Hawaii

NA.

Kure and Midway

Hawaii

unknown.

Pearl and Hermes

Hawaii

unknown.

Striped dolphin
Stenella coeruleoalba
CA/OR/WA

Southern California

29,211 (0.20)/24,782.

Hawaii

Hawaii

61,021 (0.38)/44,922.

Dall's porpoise
Phocoenoides dalli
CA/OR/WA

Southern California

25,750 (0.45)/17,954

Harbor seal
Phoca vitulina
California

Southern California

30,968 (NA)/27,348.

Hawaiian monk seal
Neomonachus schauinslandi
Hawaii
Strategic, Depleted
Endangered
Hawaii

1,415 (0.03)/1,384.

Northern elephant seal
Mirounga angustirostris
California

Southern California

179,000 (NA)/81,368.

California sea lion
Zalophus californianus
U.S. Stock

Southern California

257,606 (NA)/233,515.

Guadalupe fur seal
Arctocephalus townsendi
Mexico to California
Strategic, Depleted
Threatened
Southern California

20,000 (NA)/15,830.

Northern fur seal
Callorhinus ursinus
California

Southern California

14,050 (NA)/7,524.

1
The two humpback whale Distinct Population Segments (DPSs) making up the California, Oregon, and 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.

2
This stock is mentioned briefly in the Pacific Stock Assessment Report (Carretta
et al.,
2017) and referred to as the “Eastern North Pacific Transient” stock; however, the Alaska Stock Assessment Report contains assessments of all transient killer whale stocks in the Pacific and the Alaska Stock Assessment Report refers to this same stock as the “West Coast Transient” stock (Muto
et al.,
2017).

3
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.

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 rule and 2018 HSTT final rule. 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 NEPA requirements.

In addition, NMFS has reviewed new information in relevant SARs, any new information on active UMEs or new UMEs, and new scientific literature. Summaries of current UMEs and new scientific literature since publication of the 2018 HSTT final rule are presented below.

Unusual Mortality Events (UME)

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 that could be relevant to informing the current analysis are discussed below. Specifically, the California sea lion UME in California is still open, but will be closed soon. 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 Niño. This investigation will soon be closed. 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 have remained well above average through 2017. Strandings have continued since 2015 and remained well above average through 2019. Numbers by year are as follows: 2015 (98), 2016 (76), 2017 (61), 2018 (45), 2019 (104, as of June 28, 2019). The total number of Guadalupe fur seals from January 1, 2015, through June 28, 2019, in the UME is 438. Additionally, 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 for 2019 in Washington and Oregon is 55 seals as of June 28, 2019. 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. This California portion of this UME is 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 June 28, 2019, there have been a total of 170 strandings along the coasts of the U.S., Canada, and Mexico, with 84 of those strandings occurring along the U.S. coast. Partial necropsy examinations conducted on a subset of stranded whales have shown evidence of emaciation. 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.

New Pertinent Science Since Publication of the 2018 HSTT Final Rule

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 NMFS (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 only those under NMFS jurisdiction) for all noise exposures (both in air and underwater for amphibious species) and, while the hearing group compositions are identical, they renamed the hearing groups.

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, etc.) 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 µPa). 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 µPa, and moved away from the transducer at a received SPL of 143 dB re: 1 µPa. 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 signal, the duty cycle, and the psychological interpretation by the animal. 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 received SPLs of 117-126 dB re: 1 µPa. 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. 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 a review of the potential impacts of sonar on beaked whales, Bernaldo de Quirós
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).

Having considered this information, we have preliminarily determined that there is no new information that substantively affects our analysis of impacts on marine mammals and their habitat that appeared in the 2018 HSTT final rule, all of which remains applicable and valid for our assessment of the effects of the Navy's activities during the seven-year period of this rule.

Estimated Take of Marine Mammals

This section indicates the number of takes that NMFS is proposing to authorize, 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 application, and preliminarily 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 possible. 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).

Proposed authorized takes would 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. 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 have the potential occur through vessel collisions. Although we analyze the impacts of these potential serious injuries or mortalities that are proposed to be 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 type of harassment by considering: (1) Acoustic thresholds above which NMFS believes the best available science indicates marine mammals will be taken by Level B harassment (in this case, as defined in the military readiness definition of Level B harassment included above) or incur some degree of temporary or permanent hearing impairment; (2) the area or volume of water that will be ensonified above these levels in a day or event; (3) the density or occurrence of marine mammals within these ensonified areas; and (4) 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 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 proposes 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 and proposed rules and Appendix E of the 2018 HSTT FEIS/OEIS for detailed information.

Range to Effects

The Navy proposes 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 proposed 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 proposed 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 proposes 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

• Physical Disturbance and Strike (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 has specifically requested coverage for these species. Therefore, the likelihood of vessel strikes, and later the effects of the incidental take that is being proposed to be 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 proposes to add 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 proposes to use 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 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
Preliminary Analysis and Negligible Impact Determination
section.

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, 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, TTS, or behavioral disruption.

Summary of Requested Take From Training and Testing Activities

Based on the methods discussed in the previous sections and the Navy's model and quantitative assessment of mitigation, the Navy provided its take estimate and request for authorization of takes incidental to the use of acoustic and explosive sources for training and testing activities both annually (based on the maximum number of activities that could occur per 12-month period) and over the seven-year period covered by the 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. 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 of instances in which marine mammals are reasonably expected to be taken. NMFS also agrees that the takes by serious injury or mortality as a result of vessel strikes could occur. Note that 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.

Estimated 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. For the estimated 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 Estimates Proposed for Authorization From Acoustic and Explosive Sound Source Effects for All Training Activities

Species
Stock
7-Year total
Level B
Level A

Blue whale *
Central North Pacific
205
0

Eastern North Pacific
7,116
6

Bryde's whale †
Eastern Tropical Pacific
167
0

Hawaiian †
631
0

Fin whale *
California, Oregon, & Washington
7,731
0

Hawaiian
197
0

Humpback whale †
California, Oregon, & Washington †
7,962
7

Central North Pacific
34,437
12

Minke whale
California, Oregon, & Washington
4,119
7

Hawaiian
20,237
6

Sei whale *
Eastern North Pacific
333
0

Hawaiian
677
0

Gray whale †
Eastern North Pacific
16,703
27

Western North Pacific †
19
0

Sperm whale *
California, Oregon, & Washington
8,834
0

Hawaiian
10,341
0

Dwarf sperm whale
Hawaiian
84,232
215

Pygmy sperm whale
Hawaiian
33,431
94

Kogia
whales

California, Oregon, & Washington
38,609
149

Baird's beaked whale
California, Oregon, & Washington
8,524
0

Blainville's beaked whale
Hawaiian
23,491
0

Cuvier's beaked whale
California, Oregon, & Washington
47,178
0

Hawaiian
7,898
0

Longman's beaked whale
Hawaiian
82,293
0

Mesoplodon
spp (beaked whale guild)

California, Oregon, & Washington
25,404
0

Bottlenose dolphin
California Coastal
1,295
0

California, Oregon, & Washington Offshore
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 †
Hawaii Pelagic
4,353
0

Main Hawaiian Islands Insular †
2,710
0

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/West Coast Transient
855
0

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
California, Oregon, & Washington
357,001
57

Pacific white-sided dolphin
California, Oregon, & Washington
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
California, Oregon, & Washington
477,389
45

Hawaiian
40,800
0

Rough-toothed dolphin
Hawaiian
26,769
0

NSD
1

0
0

Short-beaked common dolphin
California, Oregon, & Washington
5,875,431
307

Short-finned pilot whale
California, Oregon, & Washington
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
California, Oregon, & Washington
777,001
5

Hawaiian
32,806
0

Dall's porpoise
California, Oregon, & Washington
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.
† Only designated stocks are ESA-listed.

1
NSD: No stock designation.

Estimated 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. 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 Estimates Proposed for Authorization From Acoustic and Explosive Sound Source Effects for All Testing Activities

Species
Stock
7-Year total
Level B
Level A

Blue whale *
Central North Pacific
93
0

Eastern North Pacific
5,679
0

Bryde's whale †
Eastern Tropical Pacific
97
0

Hawaiian †
278
0

Fin whale *
California, Oregon, & Washington
6,662
7

Hawaiian
108
0

Humpback whale †
California, Oregon, & Washington †
4,961
0

Central North Pacific
23,750
19

Minke whale
California, Oregon, & Washington
1,855
0

Hawaiian
9,822
7

Sei whale *
Eastern North Pacific
178
0

Hawaiian
329
0

Gray whale †
Eastern North Pacific
13,077
9

Western North Pacific †
15
0

Sperm whale *
California, Oregon, & Washington
7,409
0

Hawaiian
5,269
0

Dwarf sperm whale
Hawaiian
43,374
197

Pygmy sperm whale
Hawaiian
17,396
83

Kogia
whales

California, Oregon, & Washington
20,766
94

Baird's beaked whale
California, Oregon, & Washington
4,841
0

Blainville's beaked whale
Hawaiian
11,455
0

Cuvier's beaked whale
California, Oregon, & Washington
30,180
28

Hawaiian
3,784
0

Longman's beaked whale
Hawaiian
41,965
0

Mesoplodon
spp (beaked whale guild)

California, Oregon, & Washington
16,383
15

Bottlenose dolphin
California Coastal
11,158
0

California, Oregon, & Washington 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 †
Hawaii Pelagic
2,287
0

Main Hawaiian Islands Insular †
1,256
0

Northwestern Hawaiian Islands
837
0

Fraser's dolphin
Hawaiian
85,193
9

Killer whale
Eastern North Pacific Offshore
236
0

Eastern North Pacific Transient/West Coast Transient
438
0

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
California, Oregon, & Washington
280,066
22

Pacific white-sided dolphin
California, Oregon, & Washington
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
California, Oregon, & Washington
339,334
24

Hawaiian
19,027
0

Rough-toothed dolphin
Hawaiian
14,851
0

NSD
1

0
0

Short-beaked common dolphin
California, Oregon, & Washington
3,795,732
304

Short-finned pilot whale
California, Oregon, & Washington
6,253
0

Hawaiian
29,269
0

Spinner dolphin
Hawaii Island
1,394
0

Hawaii Pelagic
9,534
0

Kauai & Niihau
9,277
0

Oahu & 4-Island
1,987
0

Striped dolphin
California, Oregon, & Washington
371,328
20

Hawaiian
16,270
0

Dall's porpoise
California, Oregon, & Washington
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.
† Only designated stocks are ESA-listed.

1
NSD: No stock designation.

Estimated 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; Félix, 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 most vulnerable marine mammals are those that spend extended periods of time at the surface in order to restore oxygen levels within their tissues after deep dives (
e.g.,
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 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 occured 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 proposed 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 (which has occasionally occurred). 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 those 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 zero 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 (with a 78 percent chance that greater than 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 proposed 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 proposing, no change in the number of takes by serious injury or mortality due to vessel strikes.

Small 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.), 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, their 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 (and is proposing for authorization) 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 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 additional 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. 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 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 relative likelihood. To estimate the percent likelihood of striking a particular species of large whale, we multiplied the relative likelihood of striking each species by the total probability of striking a whale (
i.e.,
78 percent, as described by the Navy's probability analysis above). We also calculated 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.,
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 act

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2019-18850. Public record. Not legal advice.