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
Federal RegisterJul 10, 2020
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 218
[Docket No. 200625-0169]
RIN 0648-BJ06
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to the U.S. Navy Training and Testing Activities in the Hawaii-Southern California Training and Testing Study Area
AGENCY:
National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.
ACTION:
Final rule; notification of issuance of Letters of Authorization.
SUMMARY:
NMFS, upon request from the U.S. Navy (Navy), issues these regulations pursuant to the Marine Mammal Protection Act (MMPA) to govern the taking of marine mammals incidental to the training and testing activities conducted in the Hawaii-Southern California Training and Testing (HSTT) Study Area over the course of seven years, effectively extending the time period from December 20, 2023, to December 20, 2025. In August 2018, the MMPA was amended by the John S. McCain National Defense Authorization Act (NDAA) for Fiscal Year 2019 to allow for seven-year authorizations for military readiness activities, as compared to the previously allowed five years. The Navy's activities qualify as military readiness activities pursuant to the MMPA as amended by the NDAA for Fiscal Year 2004. These regulations, which allow for the issuance of Letters of Authorization (LOAs) for the incidental take of marine mammals during the described activities and timeframes, prescribe the permissible methods of taking and other means of effecting the least practicable adverse impact on marine mammal species or stocks and their habitat, and establish requirements pertaining to the monitoring and reporting of such taking.
DATES:
Effective from July 10, 2020, to December 20, 2025.
ADDRESSES:
Copies of the Navy's applications, NMFS' proposed rule for these regulations, NMFS' proposed and final rules and subsequent LOAs for the associated five-year HSTT Study Area regulations, other supporting documents cited herein, and a list of the references cited in this document may be obtained online at:
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
In case of problems accessing these documents, please use the contact listed here (see
FOR FURTHER INFORMATION CONTACT
).
FOR FURTHER INFORMATION CONTACT:
Wendy Piniak, Office of Protected Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Purpose of Regulatory Action
These regulations, issued under the authority of the MMPA (16 U.S.C. 1361
et seq.
), extend the framework for authorizing the take of marine mammals incidental to the Navy's training and testing activities (which qualify as military readiness activities) from the use of sonar and other transducers, in-water detonations, air guns, impact pile driving/vibratory extraction, and the movement of vessels throughout the HSTT Study Area. The HSTT Study Area is comprised of established operating and warning areas across the north-central Pacific Ocean, from the mean high tide line in Southern California west to Hawaii and the International Date Line. The Study Area includes the at-sea areas of three existing range complexes (the Hawaii Range Complex, the Southern California (SOCAL) Range Complex, and the Silver Strand Training Complex), and overlaps a portion of the Point Mugu Sea Range (PMSR). Also included in the Study Area are Navy pierside locations in Hawaii and Southern California, Pearl Harbor, San Diego Bay, and the transit corridor
1
on the high seas where sonar training and testing may occur.
1
Vessel transit corridors are the routes typically used by Navy assets to traverse from one area to another. The route depicted in Figure 2-1 of the Navy's March 2019 rulemaking/LOA application is the shortest route between Hawaii and Southern California, making it the quickest and most fuel efficient. The depicted vessel transit corridor is notional and may not represent the actual routes used by ships and submarines transiting from Southern California to Hawaii and back. Actual routes navigated are based on a number of factors including, but not limited to, weather, training, and operational requirements.
NMFS received an application from the Navy requesting to extend NMFS' existing MMPA regulations (50 CFR part 218, subpart H; hereafter “2018 HSTT regulations”) that authorize the take of marine mammals incidental to Navy training and testing activities conducted in the HSTT Study Area to cover seven years of the Navy's activities, instead of five. Take is anticipated to occur by Level A harassment and Level B harassment as well as a very small number of serious injuries or mortalities incidental to the Navy's training and testing activities.
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs the Secretary of Commerce (as delegated to NMFS) to allow, upon request, the incidental, but not intentional taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if, after notice and public comment, the agency makes certain findings and issues regulations that set forth permissible methods of taking pursuant to that activity, as well as monitoring and reporting requirements. Section 101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR part 216, subpart I, provide the legal basis for issuing this final rule and the subsequent LOAs. As directed by this legal authority, this final rule contains mitigation, monitoring, and reporting requirements.
Summary of Major Provisions Within the Final Rule
Following is a summary of the major provisions of this final rule regarding the Navy's activities. Major provisions include, but are not limited to:
• The use of defined powerdown and shutdown zones (based on activity);
• Measures to reduce or eliminate the likelihood of ship strikes;
• Activity limitations in certain areas and times that are biologically important (
i.e.,
for foraging, migration, reproduction) for marine mammals;
• Implementation of a Notification and Reporting Plan (for dead, live stranded, or marine mammals struck by a vessel); and
• Implementation of a robust monitoring plan to improve our understanding of the environmental effects resulting from the Navy training and testing activities.
Additionally, the rule includes an adaptive management component that allows for timely modification of mitigation or monitoring measures based on new information, when appropriate.
Background
The MMPA prohibits the “take” of marine mammals, with certain exceptions. Sections 101(a)(5)(A) and (D) of the MMPA direct the Secretary of Commerce (as delegated to NMFS) to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are issued or, if the taking is limited to harassment, a notice of a proposed
authorization is provided to the public for review and the opportunity to submit comments.
An authorization for incidental takings shall be granted if NMFS finds that the taking will have a negligible impact on the species or stocks and will not have an unmitigable adverse impact on the availability of the species or stocks for taking for subsistence uses (where relevant). Further, NMFS must prescribe the permissible methods of taking and other means of effecting the least practicable adverse impact on the affected species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of such species or stocks for taking for certain subsistence uses (referred to in this rule as “mitigation measures”); and requirements pertaining to the monitoring and reporting of such takings. The MMPA defines “take” to mean to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal. The
Analysis and Negligible Impact Determination
section below discusses the definition of “negligible impact.”
The NDAA for Fiscal Year 2004 (2004 NDAA) (Pub. L. 108-136) amended section 101(a)(5) of the MMPA to remove the “small numbers” and “specified geographical region” provisions indicated above and amended the definition of “harassment” as applied to a “military readiness activity.” The definition of harassment for military readiness activities (section 3(18)(B) of the MMPA) is: (i) Any act that injures or has the significant potential to injure a marine mammal or marine mammal stock in the wild (Level A Harassment); or (ii) Any act that disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing disruption of natural behavioral patterns, including, but not limited to, migration, surfacing, nursing, breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned or significantly altered (Level B Harassment). In addition, the 2004 NDAA amended the MMPA as it relates to military readiness activities such that least practicable adverse impact shall include consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity.
More recently, section 316 of the NDAA for Fiscal Year 2019 (2019 NDAA) (Pub. L. 115-232), signed on August 13, 2018, amended the MMPA to allow incidental take rules for military readiness activities under section 101(a)(5)(A) to be issued for up to seven years. Prior to this amendment, all incidental take rules under section 101(a)(5)(A) were limited to five years.
Summary of Request
On December 27, 2018, NMFS published a five-year final rule governing the taking of marine mammals incidental to Navy training and testing activities conducted in the HSTT Study Area (83 FR 66846; hereafter “2018 HSTT final rule”). Previously, on August 13, 2018, and towards the end of the time period in which NMFS was processing the Navy's request for the 2018 regulations, the 2019 NDAA amended the MMPA for military readiness activities to allow incidental take regulations to be issued for up to seven years instead of the previous five years. The Navy's training and testing activities conducted in the HSTT Study Area qualify as military readiness activities pursuant to the MMPA, as amended by the 2004 NDAA. On March 11, 2019 the Navy submitted an application requesting that NMFS extend the 2018 HSTT regulations and associated LOAs such that they would cover take incidental to seven years of training and testing activities instead of five, extending the expiration date from December 20, 2023 to December 20, 2025.
In its 2019 application, the Navy proposed no changes to the nature of the specified activities covered by the 2018 HSTT final rule, the level of activity within and between years will be consistent with that previously analyzed in the 2018 HSTT final rule, and all activities will be conducted within the same boundaries of the HSTT Study Area identified in the 2018 HSTT final rule. Therefore, the training and testing activities (
e.g.,
equipment and sources used, exercises conducted) and the mitigation, monitoring, and nearly all reporting measures are identical to those described and analyzed in the 2018 HSTT final rule. The only changes included in the Navy's request were to conduct those same activities in the same region for an additional two years. In its request, the Navy included all information necessary to identify the type and amount of incidental take that may occur in the two additional years so NMFS could determine whether the analyses and conclusions regarding the impacts of the proposed activities on marine mammal species and stocks previously reached for five years of activities remain applicable for seven years of identical activity.
The purpose of the Navy's training and testing activities is to ensure that the Navy meets its mission mandated by federal law (10 U.S.C. 8062), which is to maintain, train, and equip combat-ready naval forces capable of winning wars, deterring aggression, and maintaining freedom of the seas. The Navy executes this responsibility by establishing and executing training programs, including at-sea training and exercises, and ensuring naval forces have access to the ranges, operating areas (OPAREAs), and airspace needed to develop and maintain skills for conducting naval activities. The Navy's mission is achieved in part by conducting training and testing within the HSTT Study Area.
The Navy's March 11, 2019, rulemaking and LOA extension application (hereafter “2019 Navy application”) reflects the same compilation of training and testing activities presented in the Navy's October 13, 2017, initial rulemaking and LOA application (hereafter “2017 Navy application”) and the 2018 HSTT regulations that were subsequently promulgated, which can be found at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
These activities are deemed by the Navy necessary to accomplish military readiness requirements and are anticipated to continue into the reasonably foreseeable future. The 2019 Navy application and this rule cover training and testing activities that will occur over seven years, including the five years already authorized under the 2018 HSTT regulations, with the regulations valid from the publication date of this final rule through December 20, 2025.
Summary of the Regulations
NMFS is extending the incidental take regulations and associated LOAs through December 20, 2025, to cover the same Navy activities covered by the 2018 HSTT regulations. The 2018 HSTT final rule was recently published and its analysis remains current and valid. In its 2019 application, the Navy proposed no changes to the nature (
e.g.,
equipment and sources used, exercises conducted) or level of the specified activities within or between years or to the boundaries of the HSTT Study Area. The mitigation, monitoring, and nearly all reporting measures (described below) will be identical to those described and analyzed in the 2018 HSTT final rule. The regulatory language included at the end of this final rule, which will be published at 50 CFR part 218, subpart H, also is the same as the HSTT 2018 regulations, except for a small number of technical changes. No new information has been received from the
Navy, or otherwise become available to NMFS, since publication of the 2018 HSTT final rule that significantly changes the analyses supporting the 2018 findings. Where there is any new information pertinent to the descriptions, analyses, or findings required to authorize incidental take for military readiness activities under MMPA section 101(a)(5)(A), that information is provided in the appropriate sections below.
Because the activities included in the 2019 Navy application have not changed and the analyses and findings included in the documents provided and produced in support of the recently published 2018 HSTT final rule remain current and applicable, this final rule relies heavily on and references to the applicable information and analyses in those documents. Below is a list of the primary documents referenced in this final rule. The list indicates the short name by which the document is referenced in this final rule, as well as the full titles of the cited documents. All of the documents can be found at:
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities
and
http://www.hstteis.com/.
• NMFS June 26, 2018, Hawaii-Southern California Training and Testing (HSTT) proposed rule (83 FR 29872; hereafter “2018 HSTT proposed rule”);
• NMFS December 27, 2018, Hawaii-Southern California Training and Testing (HSTT) final rule (83 FR 66846; hereafter “2018 HSTT final rule”);
• NMFS September 13, 2019, Hawaii-Southern California Training and Testing (HSTT) proposed rule (84 FR 48388; hereafter “2019 HSTT proposed rule”);
• Navy October 13, 2017, MMPA rulemaking and LOA application (hereafter “2017 Navy application”);
• Navy March 11, 2019, MMPA rulemaking and LOA extension application (hereafter “2019 Navy application”); and
• October 26, 2018, Hawaii-Southern California Training and Testing (HSTT) Final Environmental Impact Statement/Overseas Environmental Impact Statement (FEIS/OEIS) (hereafter “2018 HSTT FEIS/OEIS”).
Description of the Specified Activity
The Navy requested authorization to take marine mammals incidental to conducting training and testing activities. The Navy has determined that acoustic and explosives stressors are most likely to result in impacts on marine mammals that could rise to the level of harassment. A small number of serious injuries or mortalities are also possible from vessel strikes or exposure to explosive detonations. Detailed descriptions of these activities are provided in Chapter 2 of the 2018 HSTT FEIS/OEIS and in the 2017 and 2019 Navy applications.
Overview of Training and Testing Activities
The Navy routinely trains and tests in the HSTT Study Area in preparation for national defense missions. Training and testing activities and components covered in the 2019 Navy application are described in detail in the
Overview of Training and Testing Activities
sections of the 2018 HSTT proposed rule, the 2018 HSTT final rule, and Chapter 2 (
Description of Proposed Action and Alternatives
) of the 2018 HSTT FEIS/OEIS. Each military training and testing activity described meets mandated Fleet requirements to deploy combat-ready forces. The Navy proposed no changes to the specified activities described and analyzed in the 2018 HSTT final rule. The boundaries of the HSTT Study Area (see Figure 2-1 of the 2019 Navy application); the training and testing activities (
e.g.,
equipment and sources used, exercises conducted); manner of or amount of vessel movement; and standard operating procedures presented in this final rule are identical to those described and analyzed in the 2018 HSTT final rule.
Dates and Duration
The specified activities will occur at any time during the seven-year period of validity of the regulations. The number of training and testing activities are described in the
Detailed Description of the Specified Activities
section (Tables 1 through 5).
Geographical Region
The geographic extent of the HSTT Study Area is identical to that described in the 2018 HSTT final rule. The HSTT Study Area (see Figure 2-1 of the 2019 Navy application) is comprised of established operating and warning areas across the north-central Pacific Ocean, from the mean high tide line in Southern California west to Hawaii and the International Date Line. The Study Area includes the at-sea areas of three existing range complexes (the Hawaii Range Complex, the Southern California (SOCAL) Range Complex, and the Silver Strand Training Complex), and overlaps a portion of the Point Mugu Sea Range (PMSR). Also included in the Study Area are Navy pierside locations in Hawaii and Southern California, Pearl Harbor, San Diego Bay, and the transit corridor
2
on the high seas where sonar training and testing may occur.
2
Vessel transit corridors are the routes typically used by Navy assets to traverse from one area to another. The route depicted in Figure 2-1 of the 2019 Navy application is the shortest route between Hawaii and Southern California, making it the quickest and most fuel efficient. The depicted vessel transit corridor is notional and may not represent the actual routes used by ships and submarines transiting from Southern California to Hawaii and back. Actual routes navigated are based on a number of factors including, but not limited to, weather, training, and operational requirements.
A Navy range complex consists of geographic areas that encompass a water component (above and below the surface) and airspace, and may encompass a land component where training and testing of military platforms, tactics, munitions, explosives, and electronic warfare systems occur. Range complexes include established OPAREAs, which may be further divided to provide better control of the area for safety reasons. Additional detail on range complexes and testing ranges was provided in the
Duration and Location
section of the 2018 HSTT proposed rule; please see the 2018 HSTT proposed rule or the 2017 Navy application for more information and maps.
Description of Acoustic and Explosive Stressors
The Navy uses a variety of sensors, platforms, weapons, and other devices, including ones used to ensure the safety of Sailors and Marines, to meet its statutory mission. Training and testing with these systems may introduce acoustic (sound) energy or shock waves from explosives into the environment. The specific components that could act as stressors by having direct or indirect impacts on the environment are described in detail in the
Description of Acoustic and Explosive Stressors
section of the 2018 HSTT final rule and Chapter 2 (
Description of Proposed Action and Alternatives
) of the 2018 HSTT FEIS/OEIS. The Navy proposes no changes to the nature of the specified activities and, therefore, the acoustic and explosive stressors are identical to those described and analyzed in the 2018 HSTT final rule.
Other Stressor—Vessel Strike
Vessel strikes are not specific to any particular training or testing activity, but rather a limited, sporadic, and incidental result of Navy vessel movement within the HSTT Study Area. Navy vessels transit at speeds that are optimal for fuel conservation or to meet training and testing requirements. The average speed of large Navy ships ranges between 10 and 15 knots and
submarines generally operate at speeds in the range of 8 to 13 knots, while a few specialized vessels can travel at faster speeds. By comparison, this is slower than most commercial vessels where full speed for a container ship is typically 24 knots (Bonney and Leach, 2010), with average vessel speeds along the California coast recently reported to be between 14 and 18 knots (Moore
et al.,
2018).
Should a vessel strike occur, it would likely result in incidental take from serious injury and/or mortality and, accordingly, for the purposes of the analysis we assume that any ship strike would result in serious injury or mortality. The Navy proposed no changes to the nature of the specified activities, the training and testing activities, the manner of or amount of vessel movement, or standard operating procedures described in the 2018 HSTT final rule. Therefore, the description of vessel strikes as a stressor is the same as that presented in the
Other Stressor—Vessel Strike
sections of the 2018 HSTT proposed rule and 2018 HSTT final rule.
Detailed Description of the Specified Activities
The Navy's specified activities are presented and analyzed as a representative year of training to account for the natural fluctuation of training cycles and deployment schedules in any seven-year period. In the 2018 HSTT final rule, NMFS analyzed the potential impacts of these activities (
i.e.,
incidental take of marine mammals) based on the Navy conducting three years of a representative level of activity and two years of a maximum level of activity. For the purposes of this rulemaking, the Navy presented and NMFS analyzed activities based on the additional two years of training and testing consisting of an additional one year of a maximum level of activity and one year of a representative level of activity consistent with the pattern set forth in the 2018 HSTT final rule, the 2018 HSTT FEIS/OEIS, and the 2017 Navy application.
Training Activities
The number of planned training activities that could occur annually and the duration of those activities remains identical to those presented in Table 4 of the 2018 HSTT final rule, and are not repeated here. The number of planned training activities that could occur over the seven-year period are presented in Table 1. The table is organized according to primary mission areas and includes the activity name, associated stressors applicable to these regulations, sound source bin, number of proposed activities, and locations of those activities in the HSTT Study Area. For further information regarding the primary platform used (
e.g.,
ship or aircraft type) see Appendix A (
Navy Activity Descriptions
) of the 2018 HSTT FEIS/OEIS.
Table 1—Training Activities Analyzed for Seven-Year Period in the HSTT Study Area
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
1,309
4,480
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
1,820
1,820
651
644
HSTT Transit Corridor
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.
Testing Activities
The number of planned testing activities that could occur annually and the duration of those activities are identical to those presented in Tables 5 through 8 of the 2018 HSTT final rule, and are not repeated here. Similar to the 2017 Navy application, the Navy's planned testing activities here are based on the level of testing activities anticipated to be conducted into the reasonably foreseeable future, with adjustments that account for changes in the types and tempo (increases or decreases) of testing activities to meet current and future military readiness requirements. The number of planned testing activities that could occur for the seven-year period are presented in Tables 2 through 5.
Naval Air Systems Command
The Naval Air Systems Command testing activities that could occur over the seven-year period within the HSTT Study Area are presented in Table 2.
Table 2—Naval Air Systems Command Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area
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 Naval Sea Systems Command testing activities that could occur over the seven-year period within the HSTT Study Area are presented in Table 3.
Table 3—Naval Sea Systems Command Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area
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 Office of Naval Research testing activities that could occur over the seven-year period within the HSTT Study Area are presented in Table 4.
Table 4—Office of Naval Research Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area
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 Naval Information Warfare Systems Command testing activities that could occur over the seven-year period within the HSTT Study Area are presented in Table 5.
Table 5—Naval Information Warfare Systems Command Testing Activities Analyzed for Seven-Year Period in the HSTT Study Area
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 planned training and testing activities over a seven-year period in the HSTT Study Area that were analyzed in the 2019 Navy application and for this final rule. The annual numbers for acoustic source classes, explosive source bins, and airgun sources, as well as the annual pile driving and removal activities associated with Navy training and testing activities in the HSTT Study Area are identical to those presented in Tables 9 through 12 of the 2018 HSTT final rule, and are not repeated here. Consistent with the periodicity in the 2018 HSTT final rule, the Navy included the addition of two pile driving/extraction activities for each of the two additional years.
Table 6 describes the acoustic source classes (
i.e.,
low-frequency (LF), mid-frequency (MF), and high-frequency (HF)) that could occur over seven years under the planned training and testing activities. Acoustic source bin use in the planned activities would vary annually. The seven-year totals for the planned training and testing activities take into account that annual variability.
Table 6—Acoustic Source Classes Analyzed and Number Used for Seven-Year Period for Training and Testing Activities in the HSTT Study Area
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
LF sources greater than 200 dB
H
0
1,365
LF4
LF sources equal to 180 dB and up to 200 dB
H
C
0
0
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
Hull-mounted submarine sonars (
e.g.,
AN/BQQ-10)
H
12,550
5,403
HF2
HF Marine Mammal Monitoring System
H
0
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
MF systems operating above 200 dB
H
1,503
3,290
ASW2
MF Multistatic Active Coherent sonobuoy (
e.g.,
AN/SSQ-125)
C
4,824
32,900
ASW3
MF towed active acoustic countermeasure systems (
e.g.,
AN/SLQ-25)
H
37,385
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
Lightweight torpedo (
e.g.,
MK 46, MK 54, or Anti-Torpedo Torpedo)
C
1,605
6,454
TORP2
Heavyweight torpedo (
e.g.,
MK 48)
C
3,515
2,756
TORP3
C
0
315
Forward Looking Sonar (FLS): Forward or upward looking object avoidance sonars used for ship navigation and safety
FLS2
HF sources with short pulse lengths, narrow beam widths, and focused beam patterns
H
196
3,424
FLS3
VHF sources with short pulse lengths, narrow beam widths, and focused beam patterns
H
0
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
MF SAS systems
H
0
13,720
SAS2
HF SAS systems
H
6,297
60,088
SAS3
VHF SAS systems
H
0
32,200
SAS4
MF to HF broadband mine countermeasure sonar
H
294
0
Broadband Sound Sources (BB): Sonar systems with large frequency spectra, used for various purposes
BB4
LF to MF oceanographic source
H
0
6,414
BB7
LF oceanographic source
C
0
196
BB9
MF optoacoustic source
H
0
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 planned 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 could occur during a 24-hour period. Annually, for impact pile driving, the Navy will drive 119 piles, two times a year for a total of 238 piles. Over the seven-year period of the rule, the Navy will drive a total of 1,666 piles by impact pile driving. Annually, for vibratory pile extraction, the Navy will extract 119 piles, two times a year for a total of 238 piles. Over the seven-year period of the rule, the Navy will extract a total of 1,666 piles by vibratory pile extraction.
Table 8—Summary of Pile Driving and Removal Activities per 24-Hour Period in the HSTT Study Area
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 planned 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 will be especially concentrated near San Diego, California and Pearl Harbor, Hawaii. There is no seasonal differentiation in Navy vessel use because of continual operational requirements from Combatant Commanders. The majority of large vessel traffic occurs between the installations and the OPAREAs. Support craft will be more concentrated in the coastal waters in the areas of naval installations, ports, and ranges. Activities involving vessel movements occur intermittently and are variable in duration, ranging from a few hours up to weeks.
The manner in which Navy vessels will be used during training and testing activities, the speeds at which they operate, the number of vessels that will be used during various activities, and the locations in which Navy vessel movement will be concentrated within the HSTT Study Area have not changed from those analyzed in the 2018 HSTT final rule. The only change related to the Navy's request regarding Navy vessel movement is the vessel use associated with the additional two years of Navy activities.
Standard Operating Procedures
For training and testing to be effective, personnel must be able to safely use their sensors and weapon systems as they are intended to be used in a real-world situation and to their optimum capabilities. While standard operating procedures are designed for the safety of personnel and equipment and to ensure the success of training and testing activities, their implementation often yields additional benefits on environmental, socioeconomic, public health and safety, and cultural resources. Because standard operating procedures are essential to safety and mission success, the Navy considers them to be part of the planned activities and included them in the environmental analysis. Details on standard operating procedures were provided in the 2018 HSTT proposed rule; please see the 2018 HSTT proposed rule, the 2017 Navy application, and Chapter 2 (
Description of Proposed Action and Alternatives
) of the 2018 HSTT FEIS/OEIS for more information. The Standard Operating Procedures for the seven-year period will be identical to those in place under the 2018 HSTT final rule.
Comments and Responses
On May 8, 2019, we published a notice of receipt (NOR) in the
Federal Register
(84 FR 20105) for the Navy's application to effectively extend the five-year 2018 HSTT regulations to seven years, and requested comments and information related to the Navy's request. The review and comment period for the NOR ended on June 7, 2019. We reviewed and considered all comments and information received on the NOR in development of the proposed rule. We published the proposed seven-year rule for the Navy's HSTT activities in the
Federal Register
on September 13, 2019 (83 FR 48388),
with a 30-day comment period. In that proposed rule, we requested public input on the request for authorization described therein, our analyses, and the proposed authorizations and requested that interested persons submit relevant information, suggestions, and comments. During the 30-day comment period, we received 30 comment letters. Of this total, one submission was from the Marine Mammal Commission (hereafter “Commission”), two letters were from organizations or individuals acting in an official capacity (
e.g.,
non-governmental organizations (NGOs)) and 27 submissions were from private citizens. Both the Commission and NGOs included their comments submitted on the 2018 HSTT proposed five-year rule, which the seven-year rule here is nearly identical to. The Commission did not reiterate their 2018 HSTT proposed rule recommendations in their comment letter but maintained that the recommendations that NMFS did not incorporate into the 2018 HSTT final rule are still relevant and pertain to the extension of the five-year rule and asked that they be reviewed again in the course of considering the new seven-year rule. One letter from NGOs attached their 2018 HSTT proposed rule comment letter. They stated that “most of the issues raised [in their 2018 HSTT proposed rule comment letter] were not adequately addressed in the 2018-2023 Final Rule” and asked that NMFS renew consideration of their prior comments. To the extent they raised concerns with how “most” issues were addressed previously, they did not identify which issues those were. The second letter from NGOs also attached their comments on the 2018 HSTT proposed rule and the Notice of Receipt of the 2017 Navy application.
NMFS has reviewed and considered all public comments received on the 2019 HSTT proposed rule and issuance of the LOAs. In considering the comments received we realized that our responses to some of the comments on the 2018 HSTT proposed rule could benefit from additional detail and/or clarification. Accordingly, we are republishing the responses to comments received on the 2018 HSTT proposed rule, some of which have been updated, along with providing our responses to new comments on the 2019 proposed rule. Therefore, all relevant comments received on both the 2018 and 2019 HSTT proposed rules and our responses are presented below. We provide no response to specific comments that addressed species or statutes not relevant to our proposed authorization under section 101(a)(5)(A) of the MMPA (
e.g.,
comments related to sea turtles) or species or stocks that do not occur in the HSTT Study Area (
e.g.,
Southern Resident Killer whales).
General Comments
The majority of the 18 comment letters received on the 2018 HSTT proposed rule and 27 comment letters received on the 2019 HSTT proposed rule from private citizens expressed general opposition toward the Navy's proposed training and testing activities and requested that NMFS not issue the LOAs while one comment on the 2019 HSTT proposed rule expressed general support, with none of these general commenters providing information relevant to NMFS' decisions. Therefore, these comments were not considered further. The remaining comments are addressed below.
Comment 1:
Some commenters expressed concern with issuing LOAs for seven years.
Response:
Under section 101(a)(5)(A) of the MMPA, applicants may apply for the incidental take coverage that they need for their activities and NMFS “shall issue” the requested authorizations provided certain findings (see the
Background
section) can be made. In August 2018, Congress amended the MMPA through the NDAA for Fiscal Year 2019 to allow for seven-year authorizations for military readiness activities, as compared to the previously allowed five years. Following the statutory amendment, the Navy applied for longer term coverage for its testing and training activities in the HSTT Study Area, and with NMFS making the required findings through this rulemaking, issuance of regulations and LOAs for the longer period is appropriate.
Comment 2:
Several Commenters expressed concern and the need for increased reporting and assessment of impacts due to impacts of climate change on marine mammal populations.
Response:
We note that the Navy is required to provide annual reports to NMFS and the Adaptive Management process allows for timely modification of mitigation or monitoring measures based on new information, when appropriate (see the
Mitigation Measures
and
Monitoring
sections for additional detail). The reporting requirements included in this final rule are consistent with NMFS' regulations and the goals of the monitoring and reporting program, as discussed in the 2018 HSTT final rule.
Impact Analysis
General
Comment 3:
In a comment on the 2018 HSTT proposed rule, a Commenter recommended that the Navy provide NMFS with an acoustics analysis that addresses noise impacts on land, from the air, and underwater. Full environmental analysis of the noise would examine a suite of metrics appropriate to the array of resources impacted. The impacts should discuss potential effects on wildlife, visitors, and other noise-sensitive receivers.
The commenter also recommended that the Navy consider the following as it plans to conduct activities in the HSTT Study Area:
• Use appropriate metrics to assess potential environmental impacts on land and water.
• Determine natural ambient acoustic conditions as a baseline for analysis.
• Assess effects from cumulative noise output, incorporating noise generated from other anthropogenic sources.
• Determine distance at which noise will attenuate to natural levels.
• Assess effects that these noise levels would have on terrestrial wildlife, marine wildlife, and visitors.
• Appropriate and effective mitigation measures should be developed and used to reduce vessel strike (
e.g.,
timing activities to avoid migration, and searching for marine mammals before and during activities and taking avoidance measures).
Response:
The analysis conducted by the Navy and provided to NMFS was based on the best available science and provided NMFS with all information needed to conduct a complete and thorough analysis of the effects of Navy activities on affected marine mammals and their habitat. In addition, NMFS refers the Commenter to the 2018 HSTT FEIS/OEIS which conducted an assessment of all of the activities which comprised the proposed action and their impacts (including cumulative impacts) along with alternatives to the proposed action and their impacts to relevant resources. In the context of this MMPA rule, the Navy was not required to do ambient noise monitoring or assess impacts to wildlife other than marine mammals or to visitors/tourists. The mitigation measures in this rule include procedural measures to use trained Lookouts to observe for marine mammals within a mitigation zone before, during, and after applicable activities to avoid or reduce potential impacts wherever and whenever training and testing activities occur. Additionally, the Navy will implement
measures within mitigation areas to avoid potential impacts in key areas of importance for marine mammal foraging, reproduction, and migration. The mitigation measures in this rule also include procedural measures to minimize vessel strike (avoiding whales by 500 yds,
etc.
), mitigation areas to minimize strike in biologically important areas, and Awareness Notification Message areas wherein all vessels are alerted to stay vigilant to the presence of large whales.
Density Estimates
Comment 4:
In a comment on the 2018 HSTT proposed rule, a Commenter stated that 30 iterations or Monte Carlo simulations is low for general bootstrapping methods used in those models but understands that increasing the number of iterations in turn increases the computational time needed to run the models. Accordingly, the Commenter suggested that the Navy consider increasing the iterations from 30 to at least 200 for activities that have yet to be modeled for upcoming MMPA rulemakings for Navy testing and training activities.
Response:
In areas where there are four seasons, 30 iterations are used in NAEMO which results in a total of 120 iterations per year for each event. However, in areas where there are only two seasons, warm and cold, the number of iterations per season is increased to 60 so that 120 iterations per year are maintained. The Navy reached this number of iterations by running two iterations of a scenario and calculating the mean of exposures, then running a third iteration and calculating the running mean of exposures, then a fourth iteration and so on. This is done until the running mean becomes stable. Through this approach, it was determined 120 iterations was sufficient to converge to a statistically valid answer and provides a reasonable uniformity of exposure predictions for most species and areas. There are a few exceptions for species with sparsely populated distributions or highly variable distributions. In these cases, the running mean may not flatten out (or become stable); however, there were so few exposures in these cases that while the mean may fluctuate, the overall number of exposures did not result in significant differences in the totals. In total, the number of simulations conducted for HSTT Phase III exceeded six million simulations and produced hundreds of terabytes of data. Increasing the number of iterations, based on the discussion above, would not result in a significant change in the results, but would incur a significant increase in resources (
e.g.,
computational and storage requirements). This would divert these resources from conducting other more consequential analysis without providing for meaningfully improved data. The Navy has communicated that it is continually looking at ways to improve NAEMO and reduce data and computational requirements. As technologies and computational efficiencies improve, the Navy will evaluate these advances and incorporate them where appropriate. NMFS has reviewed the Navy's approach and concurs that it is technically sound and reflects the best available science.
Comment 5:
In a comment on the 2018 HSTT proposed rule, a Commenter had concerns regarding the Navy's pinniped density estimates. Given that a single density was provided for the respective areas and pinnipeds were assumed to occur at sea as individual animals, uncertainty does not appear to have been incorporated in the Navy's animat modeling for pinnipeds. The Navy primarily used sightings or abundance data, assuming certain correction factors, divided by an area to estimate pinniped densities. Many, if not all, of the abundance estimates had associated measures of uncertainty (
i.e.,
coefficients of variation (CV), standard deviation (SD), or standard error (SE)). Therefore, the Commenter recommended that NMFS require the Navy to specify whether and how it incorporated uncertainty in the pinniped density estimates into its animat modeling and if it did not, require the Navy to use measures of uncertainty inherent in the abundance data (
i.e.,
CV, SD, SE) similar to the methods used for cetaceans.
Response:
As noted in the cited technical report “Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and Analytical Approach for Phase III Training and Testing” (U.S. Department of the Navy, 2018), the Navy did not apply statistical uncertainty outside the survey boundaries into non-surveyed areas, since it deemed application of statistical uncertainty would not be meaningful or appropriate. We note that there are no measures of uncertainty (
i.e.,
no CV, SD, or SE) provided in NMFS Pacific Stock Assessment Report (SAR) Appendix 3 (Carretta
et al.,
2019) associated with the abundance data for any of the pinniped species present in Southern California. Although some measures of uncertainty are presented in some citations within the SAR and in other relevant publications for some survey findings, it is not appropriate for the Navy to attempt to derive summations of total uncertainty for an abundance when the authors of the cited studies and the SAR have not. For additional information regarding use of pinniped density data, see the cited “U.S. Navy Marine Species Density Database Phase III for the Hawaii-Southern California Training and Testing Study Area” Section 11 (U.S. Department of the Navy, 2017b). As a result of the lack of published applicable measures of uncertainty for pinnipeds during this analysis, the Navy did not incorporate measures of uncertainty into the pinniped density estimates. NMFS independently reviewed the methods and densities used by the Navy and concur that they are appropriate and reflect the best available science.
Comment 6:
In a comment on the 2018 HSTT proposed rule, a Commenter had concerns regarding the various areas, abundance estimates, and correction factors that the Navy used for pinnipeds. The Commenter referenced a lot of information in the context of both what the Navy used and what the Commenter argued they could have used instead and summarized the discussion with several recommendations.
For harbor seals, the area was based on the NMFS SOCAL stratum (extending to the extent of the U.S. exclusive economic zone (EEZ), 370 km from the coast) for its vessel-based surveys (
i.e.,
Barlow 2010) and the Navy applied the density estimates from the coast to 80 km offshore. The Commenter believes that this approach is inappropriate and that the Navy should use the area of occurrence to estimate the densities for harbor seals. For harbor seals, the Navy assumed that 22 percent of the stock occurred in SOCAL, citing Department of the Navy (2015). The Commenter had two concerns with this approach. First, one has to go to Department of the Navy (2015) to determine the original source of the information (Lowry
et al.,
2008; see the commenter's February 20, 2014, letter on this matter). Second, Lowry
et al.
(2008) indicated that 23.3 percent of the harbor seal population occurred in SOCAL, not 22 percent as used by the Navy. Therefore, the Commenter recommended that, at the very least, NMFS require the Navy to revise the pinniped density estimates using the extent of the coastal range (
e.g.,
from shore to 80 km offshore) of harbor seals as the applicable area, 23.3 percent of the California abundance estimate based on Lowry
et al.
(2008), and an at-sea correction factor of 65 percent based on Harvey and Goley (2011) for both seasons.
For monk seals the area was based on the areas within the 200-m isobaths in both the Main and Northwest Hawaiian Islands (MHI and NWHI, respectively) and areas beyond the 200-m isobaths in the U.S. EEZ. The Commenter asserted that some of the abundances used were not based on best available science. The Navy noted that its monk seal abundance was less than that reported by Baker
et al.
(2016), but that those more recent data were not available when the Navy's modeling process began. The Baker
et al.
(2016) data have been available for almost two years and should have been incorporated accordingly, particularly since the data would yield greater densities and the species is endangered. For monk seals, the Commenter recommended using the 2015 monk seal abundance estimate from Baker
et al.
(2016) and an at-sea correction factor of 63 percent for the MHI based on Baker
et al.
(2016) and 69 percent for the NWHI based on Harting
et al.
(2017).
For the northern fur seals, the area was based on the NMFS SOCAL stratum (extending to the extent of the U.S. EEZ, 370 km from the coast) for its vessel-based surveys (
i.e.,
Barlow, 2010). For elephant seals, California sea lions, and Guadalupe fur seals, the area was based on the Navy SOCAL modeling area. The Commenter had concerns that these areas are not based on the biology or ecology of these species. The Commenter recommended using the same representative area for elephant seals, northern fur seals, Guadalupe fur seals, and California sea lions.
The Commenter recommended using an increasing trend of 3.8 percent annually for the last 15 years for elephant seals as part of the California population and at least 31,000 as representative of the Mexico population based on Lowry
et al.
(2014). Additionally, the commenter recommended using an at-sea correction factor of 44 percent for the cold season and 48 percent for the warm season for California sea lions based on Lowry and Forney (2005).
Finally, the Commenter recommended that NMFS require the Navy to (1) specify the assumptions made and the underlying data that were used for the at-sea correction factors for Guadalupe and northern fur seals and (2) consult with experts in academia and at the NMFS Science Centers to develop more refined pinniped density estimates that account for pinniped movements, distribution, at-sea correction factors, and density gradients associated with proximity to haul-out sites or rookeries.
Response:
The Navy provided additional clarification regarding the referenced concerns about areas, abundance estimates, and correction factors that were used for pinnipeds. We note that take estimation is not an exact science. There are many inputs that go into an estimate of marine mammal exposure, and the data upon which those inputs are based come with varying levels of uncertainty and precision. Also, differences in life histories, behaviors, and distributions of stocks can support different decisions regarding methods in different situations. Different methods may be supportable in different situations, and, further, there may be more than one acceptable method to estimate take in a particular situation. Accordingly, while NMFS always ensures that the methods are technically supportable and reflect the best available science, NMFS does not prescribe any one method for estimating take (or calculating some of the specific take estimate components that the Commenter is concerned about). NMFS reviewed the areas, abundances, and correction factors used by the Navy to estimate take and concurs that they are appropriate. We note the following in further support of the analysis: while some of the suggestions the Commenter makes could provide alternate valid ways to conduct the analyses, these modifications are not required in order to have equally valid and supportable analyses and, further, would not change NMFS' determinations for pinnipeds. In addition, we note that (1) many of the specific recommendations that the Commenter makes are largely minor in nature: “44 not 47 percent,” “63 not 61 percent,” “23.3 not 22 percent” or “area being approximately 13 percent larger;” and (2) even where the recommendation is somewhat larger in scale, given the ranges of these stocks, the size of the stocks, and the number and nature of pinniped takes, recalculating the estimated take for any of these pinniped stocks using the Commenter's recommended changes would not change NMFS' assessment of impacts on the recruitment or survival of any of these stocks, or the negligible impact determination. Below, we address the Commenter's issues in more detail and, while we do not explicitly note it in every section, NMFS has reviewed the Navy's analysis and choices in relation to these comments and concurs that they are technically sound and reflect the best available science.
For harbor seals
—Based on the results from satellite tracking of harbor seals at Monterey, California and the documented dive depths (Eguchi and Harvey, 2005), the extent of the range for harbor seals in the HSTT Study Area used by the Navy (a 50 Nmi buffer around all known haul-out sites; approximately 93 km) is more appropriate than the suggested 80 km offshore suggested by Commenter.
The comment is incorrect in its claim that the NMFS and Navy did not use the best available science. Regarding the appropriate percentage of the California Current Ecosystem abundance to assign to the HSTT Study Area, the 22 percent that the Navy used is based on the most recent of the two years provided in Lowry
et al.
(2008) rather than the mean of two years, which is one valid approach. Additionally, since approximately 74 percent of the harbor seal population in the Channel Islands (Lowry
et al.,
2017) is present outside and to the north of the HSTT Study Area, it is a reasonable assumption that the 22 percent used already provides a conservative overestimate and that it would not be appropriate to apply a higher percentage of the overall population for distribution into the Navy's modeling areas.
Again, the comment is incorrect in its claim that the correction factors applied to population estimates were either unsubstantiated or incorrect. Regarding the Commenter's recommended use of an at-sea correction factor of 65 percent for both seasons based on Harvey and Goley (2011), that correction factor was specifically meant to apply to the single molting season when harbor seals are traditionally surveyed (see discussion in Lowry
et al.,
2017). Additionally, the authors of that study provided a correction factor (CF = 2.86; 35 percent) for Southern California but left open the appropriateness of that factor given the limited data available at the time. For these reasons, having separate correction factors for each of the seasons is more appropriate as detailed in Section 11.1.5 (
Phoca vitulina,
Pacific harbor seal) of the “U.S. Navy Marine Species Density Database Phase III for the Hawaii-Southern California Training and Testing Study Area” (U.S. Department of the Navy, 2017b).
For monk seals,
as detailed in Section 11.1.4 (
Neomonachus schauinslandi,
Hawaiian monk seal) of the “U.S. Navy Marine Species Density Database Phase III for the Hawaii-Southern California Training and Testing Study Area” (U.S. Department of the Navy, 2017b), the Navy consulted with the researchers and subject matter experts at the Pacific Science Center and the Monk Seal Recovery Team regarding the abundance estimates, at sea correction factors, and distribution for monk seals in the Hawaiian Islands during development
of the 2018 HSTT FEIS/OEIS throughout 2015 and the Summer of 2016, and as used subsequently in its MMPA application. The Navy incorporated the results of those consultations, including unpublished data, into the analysis of monk seals. Additional details in this regard to monk seal distributions and population trends as reflected by the abundance in the Hawaiian Islands are presented in the 2018 HSTT FEIS/OEIS in Section 3.7.2.2.9.2 (Habitat and Geographic Range) and Section 3.7.2.2.9.3 (Population Trends). The Navy has indicated that it has continued ongoing communications with researchers at the Pacific Islands Science Center and elsewhere, has accounted for the findings in the citations noted by the Commenter (Baker
et al.,
2016; Harting
et al.,
2017) as well as information in forthcoming publications provided ahead of publication via those researchers (cited as in preparation), and specifically asked for and received concurrence from subject matter experts regarding specific findings presented in the 2018 HSTT FEIS/OEIS regarding monk seals. The Navy also considered (subsequent to publication of the 2018 HSTT FEIS/OEIS) the new Main Hawaiian Islands haul-out correction factor presented in the publication by Wilson
et al.
(2017, which would be inconsistent with the use of the Baker
et al.
(2016) correction factors suggested by the Commenter), and the Harting
et al.
(2017) correction factor, and considered the new abundance numbers presented in the 2016 Stock Assessment Report, which first became available in January 2018. It is the Navy's assessment that a revision of the monk seal at-sea density would only result in small changes to the predicted effects and certainly would not change the conclusions presented in the 2018 HSTT FEIS/OEIS regarding impact on the population or the impact on the species. NMFS concurs with this conclusion. The Navy has communicated that it assumes that as part of the ongoing regulatory discussions with NMFS, changes to estimates of effects can be best dealt with in the next rulemaking given Wilson
et al.
(2017) has now also provided a totally new haulout correction factor for the Main Hawaiian Islands that was not considered in Baker
et al.
(2016), Harting
et al.
(2017), or the 2016 SAR. NMFS agrees.
For northern fur seals, elephant seals, California sea lions, and Guadalupe fur seals,
the Navy consulted with various subject matter experts regarding the abundances and distributions used in the 2018 HSTT FEIS/OEIS analyses for these species and based on those consultations and the literature available, the Navy and NMFS believe that the findings presented in the 2018 HSTT FEIS/OEIS and supporting technical reports provide the most accurate assessments available for these species. Given the demonstrated differences in the at-sea distributions of elephant seals, northern fur seals, Guadalupe fur seals, and California sea lions (Gearin
et al.,
2017; Lowry
et al.,
2014; Lowry,
et al.,
2017; Norris, 2017; Norris,
et al.,
2015; Robinson
et al.,
2012; University of California Santa Cruz and National Marine Fisheries Service, 2016), it would not be appropriate to use the same representative area for distributions of these species' population abundances. For example, California sea lions forage predominantly within 20 nmi from shore (Lowry and Forney, 2005), while tag data shows that many elephant seals (Robinson
et al.,
2012) and Guadalupe fur seals (Norris, 2017) seasonally forage in deep waters of the Pacific well outside the boundaries of the HSTT Study Area.
For northern elephant seals
(
Mirounga angustirostris,
Northern elephant seal), as detailed in Section 11.1.3 of the technical report titled
U.S. Navy Marine Species Density Database Phase III for the Hawaii-Southern California Training and Testing Study Area
(U.S. Department of the Navy, 2017b), the Navy considered a number of factors in the development of the data for this species, including the fact that not all of the elephant seal population is likely to occur exclusively within the Southern California portion of the HSTT Study Area. Given that the three main rookeries considered in this analysis are located at the northern boundary of the HSTT Study Area and that elephant seals migrate northward after the breeding season, the Navy, in consultation with subject matter experts, believes the current abundance used in the analysis is based on the best available science and represents a conservative overestimate of the number of elephant seals likely to be affected by Navy activities in the HSTT Study Area. NMFS agrees with this assessment, and it was used in the MMPA analysis.
For California sea lions,
the citation (Lowry and Forney, 2005) used as the basis for this recommendation specifically addressed the use of the Central and Northern California at-sea correction factor elsewhere, with the authors stating; “In particular, [use of the Central and Northern California at-sea correction factor] would not be appropriate for regions where sea lions reproduce, such as in the Southern California Bight (SCB) and in Mexico, . . .” Given the waters of the Southern California Bight and off Mexico overlap the HSTT Study Area and since the authors of the cited study specifically recommended not using the correction factor in the manner the Commenter suggested, the Navy does not believe use of that correction factor for the HSTT Study Area would be appropriate. NMFS concurs with this approach.
For Guadalupe fur seal
—Additional detail regarding the data used for the analysis of Guadalupe fur seals was added to the 2018 HSTT FEIS/OEIS Section 3.7.2.2.8 (
Arctocephalus townsendi,
Guadalupe Fur Seal). The Navy had integrated the latest (September 2017) unpublished data for Guadalupe fur seals from researchers in the United States and Mexico into the at-sea correction factor and density distribution of the species used in the modeling, but consultations with experts in academia and at the NMFS Science Centers and their recommendations had not been finalized before release of the Draft EIS/OEIS. Subsequently, this revision of the text was not considered critical for the final NEPA document since the new data did not provide any significant change to the conclusions reached regarding the Guadalupe fur seal population. In fact, the data indicates an increase in the population and expansion of their range concurrent with decades of ongoing Navy training and testing in the SOCAL range complex. The Navy recently supported new census and at-sea satellite tagging of Guadalupe fur seals in 2018 and 2019. These data were not available during the development of the 2018 HSTT FEIS/OEIS, but the results do not change the overall conclusions. For instance, Guadalupe fur seals tagged to date are truly pelagic and mainly transit the offshore (<2000 m) waters of the HSTT SOCAL area (Norris
et al.,
2019a, 2019b; Norris
et al.,
2020). Therefore, modeled takes are likely an over-prediction of exposure. NMFS agrees with this assessment, and it was used in the MMPA analysis.
For Northern Fur Seal
—As presented in Section 11.1.2 (
Callorhinus ursinus,
Northern fur seal) of the Navy's Density Technical Report (U.S. Department of the Navy, 2017b), the correction factor percentages for northern fur seals potentially at sea were derived from the published literature as cited (Antonelis
et al.,
1990; Ream,
et al.,
2005; Roppel, 1984).
For future EISs, the Navy explained that it did and will continue to consult with authors of the papers relevant to the analyses as well as other experts in
academia and at the NMFS Science Centers during the development of the Navy's analyses. During the development of the 2018 HSTT EIS/OEIS and as late as September 2017, the Navy had ongoing communications with various subject matter experts and specifically discussed pinniped movements, the distribution of populations within the study area to support the analyses, the pinniped haulout or at-sea correction factors, and the appropriateness of density gradients associated with proximity to haul-out sites or rookeries. As shown in the references cited, the personal communications with researchers have been made part of the public record, although many other informal discussions with colleagues have also assisted in the Navy's approach to the analyses presented.
The Navy acknowledges that there have been previous comments provided by this Commenter on other Navy range complex documents regarding the use of satellite tag movement and location data to derive at-sea pinniped density data, and the Navy asserts that previous responses to those comments remain valid. Additionally, the Commenter has noted that the “. . . Commenter continues to believe that data regarding movements and dispersion of tagged pinnipeds could yield better approximations of densities than the methods the Navy currently uses.” The Navy acknowledges that in comments to previous HSTT EIS/OEIS analyses, the Commenter has recommended this untried approach; responses to those previous comments have been provided. The Navy also notes that there have been papers suggesting the future application of Bayesian or Markov chain techniques for use in habitat modeling (
e.g.,
Redfern
et al.,
2006) and overcoming the bias introduced by interpretation of population habitat use based on non-randomized tagging locations (
e.g.,
Whitehead and Jonsen, 2013). However, the use of satellite tag location data in a Bayesian approach to derive cetacean or pinniped densities at sea has yet to be accepted, implemented, or even introduced in the scientific literature.
This issue was in fact recently discussed as part of the Density Modeling Workshop associated with the October 2017 Society for Marine Mammalogy conference. The consensus of the marine mammal scientists present was that while pinniped tag data could provide a good test case, it realistically was unlikely to be a focus of the near-term research. The working group determined that a focused technical group should be established to specifically discuss pinnipeds and data available for density surface modelling in the future. It was also discussed at the Density Modeling Workshop in October 2018. The Navy has convened a pinniped working group and NMFS Alaska Fisheries Science Center is sponsoring a demonstration project to use haul-out and telemetry data from seals in Alaska to determine the viability of such an approach.
Therefore, consistent with previous assessments and based on recent discussions with subject matter experts in academia, the NMFS Science Centers, and the National Marine Mammal Laboratory, and given there is no currently established methodology for implementing the approach suggested by the Commenter, the Navy believes that attempting to create and apply a new density derivation method at this point would introduce additional levels of uncertainty into density estimations.
For these reasons, the Navy and NMFS did not use density estimates based on pinniped tracking data. Publications reporting on satellite tag location data have been and will continue to be used to aid in the understanding of pinniped distributions and density calculations as referenced in the 2018 HSTT FEIS/OEIS and the Navy's “U.S. Navy Marine Species Density Database Phase III for the Hawaii-Southern California Training and Testing Study Area” report (U.S. Department of the Navy, 2017b). The Navy has communicated that it will continue, as it has in the past, to refine pinniped density and distributions using telemetry data and evolving new techniques (such as passive acoustic survey data) in development of the Navy's analyses. As noted above, NMFS has reviewed the Navy's methods and concurs that they are appropriate and reflect the best available science.
Comment 7:
Commenters noted that in the 2018 HSTT final rule, NMFS stated that it would incorporate the best and most recently available abundance and haul out data for monk seals into its next rulemaking, but failed to do so in the 2019 HSTT proposed rule. They argued that in light of the critical status of the monk seals, which number approximately 1,415 individuals, there is no justification for NMFS' failure to comply with the MMPA's command to incorporate the best available science into the proposed extension rule.
Response:
As described in the response to Comment 6, in developing the Marine Species Density Database Phase III for the Hawaii-Southern California Training and Testing Study Area, as part of the 2018 HSTT FEIS/OEIS, the Navy consulted with researchers and subject matter experts at NMFS' Pacific Islands Fisheries Science Center and the Monk Seal Recovery Team regarding the abundance estimates, at sea correction factors, and distribution for monk seals in the Hawaiian Islands. The Navy incorporated the results of those consultations, including unpublished data from Wilson
et al.,
then in review, into the analysis of monk seals for the 2018 HSTT FEIS/OEIS and the 2017 and 2019 Navy Applications. When developing the analysis for monk seals, the Navy, in consultation with researchers at the NMFS Pacific Islands Fisheries Science Center, incorporated an estimated increased monk seal abundance. The published SAR for Hawaiian monk seals at the time (2015) reported a population size of 1,112, however in consultation with NMFS the Navy used a population size of 1,300. This estimate was also in agreement with the population size estimates reported by Baker
et al.
(2016) (2013 = 1,291, 2014 = 1,309, 2015 = 1,324). The most recent draft 2019 SARs report a population size of 1,351 and the abundance estimate used in the Navy's analyses is within the 95 percent confidence interval (1,294-1,442; CV = 0.03). It is the Navy's assessment that a revision of the monk seal at-sea density (given the most recent abundance estimate of 1,351) would result in only very small changes to the predicted effects (particularly given the distribution of monk seals in the HSTT Study Area) and would not change the conclusions presented in the 2018 HSTT FEIS/OEIS and 2017 and 2019 Navy applications regarding impact on the population or the impact on the species. NMFS concurs with this conclusion. NMFS and the Navy will continue to consider the most recent and best available data in future EIS and MMPA rule analyses.
Comment 8:
In a comment on the 2018 HSTT proposed rule, a Commenter recommended that NMFS require the Navy to (1) specify what modeling method and underlying assumptions, including any relevant source spectra and assumed animal swim speeds and turnover rates, were used to estimate the ranges to PTS and TTS for impact and vibratory pile-driving activities, (2) accumulate the energy for the entire day of proposed activities to determine the ranges to PTS and TTS for impact and vibratory pile-driving activities, and (3) clarify why the PTS and TTS ranges were estimated to be the same for LF and HF cetaceans during impact pile driving.
Response:
As explained in Section 3.7.3.1.4.1 of the 2018 HSTT FEIS/OEIS,
the Navy measured values for source levels and transmission loss from pile driving of the Elevated Causeway System, the only pile driving activity included in the Specified Activity. The Navy reviewed the source levels and how the spectrum was used to calculate the range to effects; NMFS supports the use of these measured values for the MMPA analysis. These recorded source waveforms were weighted using the auditory weighting functions. Low-frequency and high-frequency cetaceans have similar ranges for impact pile driving since low-frequency cetaceans would be relatively more sensitive to the low-frequency sound which is below high-frequency cetaceans' best range of hearing. Neither the NMFS user spreadsheet nor NAEMO were required for calculations. An area density model was developed in MS Excel which calculated zones of influence (ZOI) to thresholds of interest (
e.g.,
behavioral response) based on durations of pile driving and the aforementioned measured and weighted source level values. The resulting area was then multiplied by density of each marine mammal species that could occur within the vicinity. This produced an estimated number of animals that could be impacted per pile, per day, and overall during the entire activity for both the impact pile driving and vibratory removal phases. NMFS reviewed the manner in which the Navy applied the frequency weighting and calculated all values and concurred with the approach.
Regarding the appropriateness of accumulating energy for the entire day, based on the best available science regarding animal reaction to sound, selecting a reasonable SEL calculation period is necessary to more accurately reflect the time period an animal would likely be exposed to the sound. The Navy factored both mitigation effectiveness and animal avoidance of higher sound levels into the impact pile driving analysis. For impact pile driving, the mitigation zone extends beyond the average ranges to PTS for all hearing groups; therefore, mitigation will help prevent or reduce the potential for exposure to PTS. The impact pile driving mitigation zone also extends beyond or into a portion of the average ranges to TTS; therefore, mitigation will help prevent or reduce the potential for exposure to all TTS or some higher levels of TTS, depending on the hearing group. Mitigation effectiveness and animal avoidance of higher sound levels were both factored into the impact pile driving analysis as most marine mammals should be able to easily move away from the expanding ensonified zone of TTS/PTS within 60 seconds, especially considering the soft start procedure, or avoid the zone altogether if they are outside of the immediate area upon startup. Marine mammals are likely to leave the immediate area of pile driving and extraction activities and be less likely to return as activities persist. However, some “naive” animals may enter the area during the short period of time when pile driving and extraction equipment is being re-positioned between piles. Therefore, an animal “refresh rate” of 10 percent was selected. This means that 10 percent of the single pile ZOI was added for each consecutive pile within a given 24-hour period to generate the daily ZOI per effect category. These daily ZOIs were then multiplied by the number of days of pile driving and pile extraction and then summed to generate a total ZOI per effect category (
i.e.,
behavioral response, TTS, PTS). The small size of the mitigation zone and its close proximity to the observation platform will result in a high likelihood that Lookouts would be able to detect marine mammals throughout the mitigation zone. NMFS concurs with the Navy's approach, and it was used in the MMPA analysis.
PTS/TTS Thresholds
Comment 9:
In a comment on the 2018 HSTT proposed rule, a Commenter supported the weighting functions and associated thresholds as stipulated in Finneran (2016), which are the same as those used for Navy Phase III activities, but points to additional recent studies that provide additional behavioral audiograms (
e.g.,
Branstetter
et al.,
2017; Kastelein
et al.,
2017b) and information on TTS (
e.g.,
Kastelein
et al.,
2017a, 2017c). However, they commented that the Navy should provide a discussion of whether those new data corroborate the current weighting functions and associated thresholds.
Response:
The NMFS Revised Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing (NMFS 2018) (Acoustic Technical Guidance), which was used in the assessment of effects for this rulemaking, compiled, interpreted, and synthesized the best available scientific information for noise-induced hearing effects for marine mammals to derive updated thresholds for assessing the impacts of noise on marine mammal hearing, including the articles that the Commenter referenced that were published subsequent to the publication of the first version of 2016 Acoustic Technical Guidance. The new data included in those articles are consistent with the thresholds and weighting functions included in the current version of the Acoustic Technical Guidance (NMFS, 2018).
NMFS will continue to review and evaluate new relevant data as it becomes available and consider the impacts of those studies on the Acoustic Technical Guidance to determine what revisions/updates may be appropriate. Thus far, no new information has been published or otherwise conveyed that would fundamentally change the assessment of impacts or conclusions of this rule. Furthermore, the recent peer-reviewed updated marine mammal noise exposure criteria by Southall
et al.
(2019a) provide identical PTS and TTS thresholds to those provided in NMFS' Acoustic Technical Guidance.
Comment 10:
In a comment on the 2018 HSTT proposed rule, Commenters stated that the criteria that NMFS has produced to estimate temporary threshold shift (TTS) and permanent threshold shift (PTS) in marine mammals are erroneous and non-conservative. Commenters cited multiple purported issues with NMFS' Acoustic Technical Guidance, such as pseudoreplication and inconsistent treatment of data, broad extrapolation from a small number of individuals, and disregarding “non-linear accumulation of uncertainty.” Commenters suggested that NMFS not rely exclusively on its auditory guidance for determining Level A harassment take, but should at a minimum retain the historical 180-dB rms Level A harassment threshold as a “conservative upper bound” or conduct a “sensitivity analysis” to “understand the potential magnitude” of the supposed errors.
Response:
NMFS disagrees with this characterization of the Acoustic Technical Guidance and the associated recommendation. The Acoustic Technical Guidance is a compilation, interpretation, and synthesis of the scientific literature that provides the best scientific information regarding the effects of anthropogenic sound on marine mammals' hearing. The technical guidance was classified as a Highly Influential Scientific Assessment and, as such, underwent three independent peer reviews, at three different stages in its development, including a follow-up to one of the peer reviews, prior to its dissemination by NMFS. In addition, there were three separate public comment periods, during which time we received and responded to similar comments on the guidance (81 FR 51694), which we cross-reference here, and more recent public and interagency review under Executive Order 13795. This review process was scientifically rigorous and
ensured that the Guidance represents the best scientific data available. Furthermore, the recent peer-reviewed updated marine mammal noise exposure criteria by Southall
et al.
(2019a) provide identical PTS and TTS thresholds to those provided in NMFS' Acoustic Technical Guidance.
The Acoustic Technical Guidance updates the historical 180 dB rms injury threshold, which was based on professional judgement (
i.e.,
no data were available on the effects of noise on marine mammal hearing at the time this original threshold was derived). NMFS disagrees with any suggestion that the use of the Acoustic Technical Guidance provides erroneous results. The 180-dB rms threshold is plainly outdated, as the best available science indicates that rms SPL is not even an appropriate metric by which to gauge potential auditory injury.
Multiple studies from humans, terrestrial mammals, and marine mammals have demonstrated less TTS from intermittent exposures compared to continuous exposures with the same total energy because hearing is known to experience some recovery in between noise exposures, which means that the effects of intermittent noise sources such as tactical sonars are likely overestimated. Marine mammal TTS data have also shown that, for two exposures with equal energy, the longer duration exposure tends to produce a larger amount of TTS. Most marine mammal TTS data have been obtained using exposure durations of tens of seconds up to an hour, much longer than the durations of many tactical sources (much less the continuous time that a marine mammal in the field would be exposed consecutively to those levels), further suggesting that the use of these TTS data are likely to overestimate the effects of sonars with shorter duration signals.
Regarding the suggestion of pseudoreplication and erroneous models, since marine mammal hearing and noise-induced hearing loss data are limited, both in the number of species and in the number of individuals available, attempts to minimize pseudoreplication would further reduce these already limited data sets. Specifically, with marine mammal behavioral temporary threshold shift studies, behaviorally derived data are only available for two mid-frequency cetacean species (bottlenose dolphin, beluga) and two phocids (in-water) pinniped species (harbor seal and northern elephant seal), with otariid (in-water) pinnipeds and high-frequency cetaceans only having behaviorally-derived data from one species. Arguments from Wright (2015) regarding pseudoreplication within the TTS data are therefore largely irrelevant in a practical sense because there are so few data. Multiple data points were not included for the same individual at a single frequency. If multiple data existed at one frequency, the lowest TTS onset was always used. There is only a single frequency where TTS onset data exist for two individuals of the same species: 3 kHz for dolphins. Their TTS (unweighted) onset values were 193 and 194 dB re 1 μPa2s. Thus, NMFS believes that the current approach makes the best use of the given data. Appropriate means of reducing pseudoreplication may be considered in the future, if more data become available. Many other comments from Wright (2015) and the comments from Racca
et al.
(2015b) appear to be erroneously based on the idea that the shapes of the auditory weighting functions and TTS/PTS exposure thresholds are directly related to the audiograms;
i.e.,
that changes to the composite audiograms would directly influence the TTS/PTS exposure functions (
e.g.,
Wright (2015) describes weighting functions as “effectively the mirror image of an audiogram” (p. 2) and states, “The underlying goal was to estimate how much a sound level needs to be above hearing threshold to induce TTS.” (p. 3)). Both statements are incorrect and suggest a fundamental misunderstanding of the criteria/threshold derivation. This would require a constant (frequency-independent) relationship between hearing threshold and TTS onset that is not reflected in the actual marine mammal TTS data. Attempts to create a “cautionary” outcome by artificially lowering the composite audiogram thresholds would not necessarily result in lower TTS/PTS exposure levels, since the exposure functions are to a large extent based on applying mathematical functions to fit the existing TTS data.
Behavioral Harassment Thresholds
Comment 11:
In a comment on the 2018 HSTT proposed rule, Commenters commented on what they assert is NMFS' failure to set proper thresholds for behavioral impacts. Referencing the biphasic function that assumes an unmediated dose response relationship at higher received levels and a context-influenced response at lower received levels that NMFS uses to quantify behavioral harassment from sonar, Commenters commented that resulting functions depend on some inappropriate assumptions that tend to significantly underestimate effects. Commenters expressed concern that every data point that informs the agency's pinniped function, and nearly two-thirds of the data points informing the odontocete function (30/49), are derived from a captive animal study. Additionally, Commenters asserted that the risk functions do not incorporate (nor does NMFS apparently consider) a number of relevant studies on wild marine mammals. The Commenters stated that it is not clear from the proposed rule, or from the Navy's recent technical report on acoustic “criteria and thresholds,” on which NMFS' approach in the rule is based, exactly how each of the studies that NMFS employed was applied in the analysis, or how the functions were fitted to the data, but the available evidence on behavioral response raises concerns that the functions are not conservative for some species. Commenters recommended NMFS make additional technical information available, including from any expert elicitation and peer review, so that the public can fully comment.
Response:
The “Criteria and Thresholds for U.S. Navy Acoustic and Explosive Impacts to Marine Mammals and Sea Turtles Technical Report” (U.S. Department of the Navy, 2017a) details how the Navy's proposed method, which was determined appropriate and adopted by NMFS, accounted for the differences in captive and wild animals in the development of the behavioral response functions. The Navy used the best available science, which has been reviewed by external scientists and approved by NMFS, in the analysis. The Navy and NMFS have utilized all available data that relate known or estimable received levels to observations of individual or group behavior as a result of sonar exposure (which is needed to inform the behavioral response function) for the development of updated thresholds. Limiting the data to the small number of field studies that include these necessary data would not provide enough data with which to develop the new risk functions. In addition, NMFS agrees with the assumptions made by the Navy, including the fact that captive animals may be less sensitive, in that the scale at which a moderate to severe response was considered to have occurred is different for captive animals than for wild animals, as the agency understands those responses will be different.
The new risk functions were developed in 2016, before several recent papers were published or the data were available. As new science is published, NMFS and the Navy continue to evaluate the information. The
thresholds have been rigorously vetted among scientists and within the Navy community and then reviewed by the public before being applied—all applicable technical information considered has been shared with the public. It is not possible to revise and update the criteria and risk functions every time a new paper is published. These new papers provide additional information, and the Navy has considered them for updates to the thresholds in the future, when the next round of updated criteria will be developed. Thus far, no new information has been published or otherwise conveyed that would fundamentally change the assessment of impacts or conclusions of the HSTT FEIS/OEIS or this rule. To be included in the behavioral response function, data sets need to relate known or estimable received levels to observations of individual or group behavior. Melcon
et al.
(2012) does not relate observations of individual/group behavior to known or estimable received levels (at that individual/group). In Melcon
et al.
(2012), received levels at the HARP buoy averaged over many hours are related to probabilities of D-calls, but the received level at the blue whale individuals/group are unknown.
As noted, the derivation of the behavioral response functions is provided in the 2017 technical report titled “Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)”. The appendices to this report detail the specific data points used to generate the behavioral response functions. Data points come from published data that is readily available and cited within the technical report.
Comment 12:
In a comment on the 2018 HSTT proposed rule, Commenters stated concerns with the use of distance “cut-offs” in the behavioral harassment thresholds, and one commenter recommended that NMFS refrain from using cut-off distances in conjunction with the Bayesian BRFs and re-estimate the numbers of marine mammal takes based solely on the Bayesian BRFs.
Response:
The consideration of proximity (cut-off distances) was part of the criteria developed in consultation between the Navy and NMFS, is appropriate based on the best available science which shows that marine mammal responses to sound vary based on both sound level and distance, and was applied within the Navy's acoustic effects model. The derivation of the behavioral response functions and associated cut-off distances is provided in the 2017 technical report titled “Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)”. To account for non-applicable contextual factors, all available data on marine mammal reactions to actual Navy activities and other sound sources (or other large scale activities such as seismic surveys when information on proximity to sonar sources is not available for a given species group) were reviewed to find the farthest distance to which significant behavioral reactions were observed. These distances were rounded up to the nearest 5 or 10 km interval, and for moderate to large scale activities using multiple or louder sonar sources, these distances were greatly increased—doubled in most cases. The Navy's BRFs applied within these distances provide technically sound methods reflective of the best available science to estimate the impact and potential take under military readiness for the actions analyzed within the 2018 HSTT FEIS/OEIS and included in these regulations. NMFS has independently assessed the Navy's behavioral harassment thresholds and believes that they appropriately apply the best available science and it is not necessary to recalculate take estimates.
The Commenter also specifically expressed concern that distance “cut-offs” alleviate some of the exposures that would otherwise have been counted if the received level alone were considered. It is unclear why the Commenter finds this inherently inappropriate, as this is what the data show. As noted previously, there are multiple studies illustrating that in situations where one would expect a behavioral harassment because of the received levels at which previous responses were observed, it has not occurred when the distance from the source was larger than the distance of the first observed response.
Comment 13:
In a comment on the 2018 HSTT proposed rule regarding cut-off distances, Commenters noted that dipping sonar appears to be a significant predictor of deep-dive rates in beaked whales on Southern California Anti-submarine Warfare Range (SOAR), with the dive rate falling significantly (
e.g.,
to 35 percent of that individual's control rate) during sonar exposure, and likewise appears associated with habitat abandonment. Importantly, these effects were observed at substantially greater distances (
e.g.,
30 or more km) from dipping sonar than would otherwise be expected given the systems' source levels and the beaked whale response thresholds developed from research on hull-mounted sonar. Commenters suggested that the analysis, and associated cut-off distances, do not properly consider the impacts of dipping sonar.
Response:
The Navy relied upon the best science that was available to develop the behavioral response functions in consultation with NMFS. The Navy's current beaked whale BRF acknowledges and incorporates the increased sensitivity observed in beaked whales during both behavioral response studies and during actual Navy training events, as well as the fact that dipping sonar can have greater effects than some other sources with the same source level. Specifically, the distance cut-off for beaked whales is 50 km, larger than any other group. Moreover, although dipping sonar has a significantly lower source level than hull-mounted sonar, it is included in the category of sources with larger distance cut-offs, specifically in acknowledgement of its unpredictability and association with observed effects. This means that “takes” are reflected at lower received levels that would have been excluded because of the distance for other source types.
The referenced article (Falcone
et al.,
2017) was not available at the time the BRFs were developed. However, NMFS and the Navy have reviewed the article and concur that neither this article nor any other new information that has been published or otherwise conveyed since the 2018 HSTT proposed rule was published would change the assessment of impacts or conclusions in the 2018 HSTT FEIS/OEIS or in this rulemaking. Nonetheless, the new information and data presented in the new article were thoroughly reviewed by the Navy and will be quantitatively incorporated into future behavioral response functions, as appropriate, when and if other new data that would meaningfully change the functions would necessitate their revision.
Furthermore, ongoing Navy funded beaked whale monitoring at the same site where the dipping sonar tests were conducted has not documented habitat abandonment by beaked whales. Passive acoustic detections of beaked whales have not significantly changed over ten years of monitoring (DiMarzio
et al.,
2018, updated in 2020). From visual surveys in the area since 2006 there have been repeated sightings of: The same individual beaked whales, beaked whale mother-calf pairs, and beaked whale mother-calf pairs with mothers on their second calf (Schorr
et al.,
2018, 2020). Satellite tracking studies of beaked whale documented high site fidelity to this area (Schorr
et al.,
2018, updated in 2020).
Comment 14:
In a comment on the 2018 HSTT proposed rule regarding the behavioral thresholds for explosives, Commenters recommended that NMFS
estimate and ultimately authorize behavioral takes of marine mammals during all explosive activities, including those that involve single detonations.
Response:
The derivation of the explosive injury criteria is provided in the 2017 technical report titled “Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III),” and NMFS has applied the general rule a commenter referenced to single explosives for years,
i.e.,
that marine mammals are unlikely to respond to a single instantaneous detonation
at received levels below the TTS threshold
in a manner that would rise to the level of a take. Neither NMFS nor the Navy are aware of evidence to support the assertion that animals will have significant behavioral reactions (
i.e.,
those that would rise to the level of a take) to temporally and spatially isolated explosions below the TTS threshold.
Marine mammals may be exposed to isolated impulses in their natural environment (
e.g.,
lightning). There is no evidence to support that animals have significant behavioral responses to temporally and spatially isolated impulses (such as military explosions) that may rise to the level of “harassment” under the MMPA for military readiness activities. Still, the analysis conservatively assumes that any modeled instance of temporally or spatially separated detonations occurring in a single 24-hour period would result in harassment under the MMPA for military readiness activities. The Navy has been monitoring detonations since the 1990s and has not observed these types of reactions. To be clear, this monitoring has occurred under the monitoring plans developed specifically for shock trials, the detonations with the largest net explosive weight conducted by the Navy, and no shock trials are proposed in this Study Area.
Further, to clarify, the current take estimate framework does not preclude the consideration of animals being behaviorally disturbed during single explosions as they are counted as “taken by Level B harassment” if they are exposed above the TTS threshold, which is only 5 dB higher than the behavioral harassment threshold. We acknowledge in our analysis that individuals exposed above the TTS threshold may also be behaviorally harassed and those potential impacts are considered in the negligible impact determination.
All of the Navy's monitoring projects, reports, and publications are available on the marine species monitoring web page (
https://www.navymarinespeciesmonitoring. us/
). NMFS will continue to review applicable monitoring and science data and consider modifying these criteria when and if new information suggests it is appropriate.
Mortality and injury thresholds for explosions
Comment 15:
In a comment on the 2018 HSTT proposed rule, a Commenter recommended that NMFS require the Navy to (1) explain why the constants and exponents for onset mortality and onset slight lung injury thresholds for Phase III have been amended, (2) ensure that the modified equations are correct, and (3) specify any additional assumptions that were made.
Response:
The derivation of the explosive injury equations, including any assumptions, is provided in the 2017 technical report titled “Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)”. It is our understanding that the constants and exponents for onset mortality and onset slight lung injury were amended by the Navy since Phase II to better account for the best available science. Specifically, the equations were modified in Phase III to fully incorporate the injury model in Goertner (1982), specifically to include lung compression with depth. NMFS independently reviewed and concurred with this approach.
Comment 16:
In a comment on the 2018 HSTT proposed rule, a Commenter stated that the Navy only used the onset mortality and onset slight lung injury criteria to determine the range to effects, while it used the 50 percent mortality and 50 percent slight lung injury criteria to estimate the numbers of marine mammal takes. The Commenter believes that this approach is inconsistent with the manner in which the Navy estimated the numbers of takes for PTS, TTS, and behavioral disruption for explosive activities. All of those takes have been and continue to be based on onset, not 50-percent values. The Commenter commented on circumstances of the deaths of multiple common dolphins during one of the Navy's underwater detonation events in March 2011 (Danil and St. Leger, 2011) and indicated that the Navy's mitigation measures are not fully effective, especially for explosive activities. The Commenter believes it would be more prudent for the Navy to estimate injuries and mortalities based on onset rather than a 50-percent incidence of occurrence. The Navy did indicate that it is reasonable to assume for its impact analysis—thus its take estimation process—that extensive lung hemorrhage is a level of injury that would result in mortality for a wild animal (Department of the Navy 2017a). Thus, the Commenter asserted that it is unclear why the Navy did not follow through with that premise. The Commenter recommended that NMFS use onset mortality, onset slight lung injury, and onset GI tract injury thresholds to estimate both the numbers of marine mammal takes and the respective ranges to effect.
Response:
Based on an extensive review of the incident referred to by the Commenter, in coordination with NMFS the Navy revised and updated the mitigation for these types of events. There have been no further incidents since these mitigation changes were instituted in 2011. The Navy used the range to one percent risk of mortality and injury (referred to as “onset” in the Draft EIS/OEIS) to inform the development of mitigation zones for explosives. In all cases, the mitigation zones for explosives extend beyond the range to one percent risk of non-auditory injury, even for a small animal (representative mass = 5 kg). The 2018 HSTT FEIS/OEIS clarified that the “onset” non-auditory injury and mortality criteria are actually one percent risk criteria.
Over-predicting impacts, which would occur with the use of one percent non-auditory injury risk criteria in the quantitative analysis, would not afford extra protection to any animal. The Navy, in coordination with NMFS, has determined that the 50 percent incidence of occurrence is a reasonable representation of a potential effect and appropriate for take estimation. Although the commenter implies that the Navy did not use extensive lung hemorrhage as indicative of mortality, that statement is incorrect. Extensive lung hemorrhage is assumed to result in mortality, and the explosive mortality criteria are based on extensive lung injury data. See the 2017 technical report titled “Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III).”
Range to Effects
Comment 17:
In a comment on the 2018 HSTT proposed rule, a Commenter noted that regarding TTS, the ranges to effect provided in Table 25 of the
Federal Register
notice of the 2018 HSTT proposed rule and Table 6-4 of the 2017 Navy application appear to be incorrect. The ranges for LF cetaceans should increase with increasing sonar emission time. Therefore, the Commenter recommended that NMFS determine what the appropriate ranges to TTS for bin LF5 should be and amend
the ranges for the various functional hearing groups in the tables accordingly.
Response:
The table regarding the
Range to Temporary Threshold Shift for sonar bin LF5 over a representative range of environments within the HSTT Study Area
(Table 25 in the Proposed and Final Rules) is correct. The reason the values in the tables in the rules and the 2018 HSTT FEIS/OEIS do not change over the indicated interval (1 sec, 30 sec, 60 sec, 120 sec) is that the LF5 pulse interval is longer than these values, hence the same range to TTS in the table. The values are consistent across the board because the max source level of LF5 (<180 dB SPL) is so close to the LF cetacean TTS threshold 179 dB SEL. At such small range to effects, the resolution of NAEMO comes into play, and such small changes in range to effects cannot be discerned between the example durations.
Mitigation and Avoidance Calculations
Comment 18:
In a comment on the 2018 HSTT proposed rule, Commenters cited concerns that there was not enough information by which to evaluate the Navy's post-modeling calculations to account for mitigation and avoidance and imply that Level A takes and mortality takes may be underestimated. One Commenter recommended that NMFS (1) authorize the total numbers of model-estimated Level A harassment (PTS) and mortality takes rather than reduce the estimated numbers of takes based on the Navy's post-model analyses and (2) use those numbers, in addition to the revised Level B harassment takes, to inform its negligible impact determination analyses.
Response:
The consideration of marine mammal avoidance and mitigation effectiveness is integral to the Navy's overall analysis of impacts from sonar and explosive sources. NMFS has independently evaluated the method and agrees that it is appropriately applied to augment the model in the prediction and authorization of injury and mortality as described in the rule. Details of this analysis are provided in the Navy's 2018 technical report titled “Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and Analytical Approach for Phase III Training and Testing”; additional information on the mitigation analysis also was included in the 2018 HSTT final rule.
Sound levels diminish quickly below levels that could cause PTS. Studies have shown that all animals observed avoid areas well beyond these zones; therefore, the vast majority of animals are likely to avoid sound levels that could cause injury to their ear. As discussed in the Navy's 2018 technical report titled “Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and Analytical Approach for Phase III Training and Testing,” animats in the Navy's acoustic effects model do not move horizontally or “react” to sound in any way. However, the current best available science based on a growing body of behavioral response research shows that animals do in fact avoid the immediate area around sound sources to a distance of a few hundred meters or more depending upon the species (see Appendix B of the “Criteria and Thresholds for U.S. Navy Acoustic and Explosive Impacts to Marine Mammals and Sea Turtles Technical Report” (U.S. Department of the Navy, 2017a)) and Southall
et al.
(2019a). Avoidance to this distance greatly reduces the likelihood of impacts to hearing such as TTS and PTS. Accordingly, NMFS and the Navy's analysis appropriately applies a quantitative adjustment to the exposure results calculated by the model (which does not consider avoidance or mitigation).
Specifically, behavioral response literature, including the recent 3S and SOCAL BRS studies, indicate that the multiple species from different cetacean suborders do in fact avoid approaching sound sources by a few hundred meters or more, which would reduce received sound levels for individual marine mammals to levels below those that could cause PTS. The ranges to PTS for most marine mammal groups are within a few tens of meters and the ranges for the most sensitive group, the HF cetaceans, average about 200 m, to a maximum of 270 m in limited cases. For blue whales and other LF cetaceans, the range to PTS is 65 m for MF1 30 sec duration exposure, which is well within the mitigation zones for hull-mounted MFAS.
As discussed in the Navy's 2018 technical report titled “Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and Analytical Approach for Phase III Training and Testing” and the 2018 HSTT final rule, the Navy's acoustic effects model does not consider procedural mitigations (
i.e.,
power-down or shut-down of sonars, or pausing explosive activities when animals are detected in specific zones adjacent to the source), which necessitates consideration of these factors in the Navy's overall acoustic analysis. Credit taken for mitigation effectiveness is extremely conservative. For example, if Lookouts can see the whole area, they get credit for it in the calculation; if they can see more than half the area, they get half credit; if they can see less than half the area, they get no credit. Not considering animal avoidance and mitigation effectiveness would lead to a great overestimate of injurious impacts. NMFS concurs with the analytical approach used,
i.e.,
we believe the estimated Level A take numbers represent the maximum number of these takes that are likely to occur and it would not be appropriate to authorize a higher number or consider a higher number in the negligible impact analysis. Lastly, the Navy's 2018 technical report titled “Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and Analytical Approach for Phase III Training and Testing” very clearly explains in detail how species sightability, the Lookout's ability to observe the range to PTS (for sonar and other transducers) and mortality (for explosives), the portion of time when mitigation could potentially be conducted during periods of reduced daytime visibility (to include inclement weather and high sea state) and the portion of time when mitigation could potentially be conducted at night, and the ability for sound sources to be positively controlled (powered down) are considered in the post-modeling calculation to account for mitigation and avoidance. It is not necessary to view the many tables of numbers generated in the assessment to evaluate the method.
Comment 19:
In a comment on the 2019 HSTT proposed rule, Commenters noted that the Navy and NMFS failed to consider the maximum amount of take that is likely to occur because the Navy's computer modeled take is reduced based on unsubstantiated assumptions concerning the effectiveness of the Navy's procedural mitigation measures (primarily Lookouts with some passive acoustic monitoring) and the rates at which mammals avoid permanent threshold shift (PTS) exposure levels. Therefore, they assert that the PTS and injury (Level A) take estimates are low, and the negligible impact analysis is invalid because the numbers considered by NMFS are arbitrary. They provide the following example to illustrate their point: 2013 model-estimated PTS for blue whales was 116 individual instances of take (see Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific, Post-Model Quantitative Analysis of Animal Avoidance Behavior and Mitigation Effectiveness for Hawaii-Southern California Training and Testing, 39
(Table 5-1) (August 27, 2013)). After implementation of mitigation, the estimated instances of PTS were reduced to 9 instances, and after assumed rates of animal avoidance were added, the estimated instances of take were reduced to 0. The Commenters asserted that in other words, the Navy assumed that it would be able to reduce 92 percent of modeled PTS for blue whales based on the effectiveness of its Lookouts and that PTS take estimates for other cetaceans are reduced at similar rates. The Commenters noted that there is no apparent rational basis for the extremely high rates of effectiveness (over 90 percent) the Navy claims for its procedural mitigation. They asserted that it is difficult to assess these claims, as neither the Navy nor NMFS has disclosed the actual numbers used to assess mitigation effectiveness for cetaceans along the four factors (species sightability, observation area, visibility, positive control). The Commenters requested that NMFS disclose those numbers and justify its reliance on them. The Commenters also incorporated the critiques raised by the Marine Mammal Commission in its 2017 comment letter concerning: (i) The comparative ineffectiveness of marine observers compared to line-transect observers; and (ii) the assumed 95 percent animal avoidance rate for PTS. In particular, they assert that references cited by NMFS and the Navy do not support the conclusion that cetaceans (other than beaked whales) regularly avoid sonar sources so as to mitigate PTS.
Response:
As noted in response to a similar comment on the 2018 HSTT proposed rule (see Comment 18 above), the consideration of marine mammal avoidance and mitigation effectiveness is integral to the Navy's overall analysis of impacts from sonar and explosive sources. NMFS has independently evaluated the method and agrees that it is appropriately applied to augment the model in the prediction and authorization of injury and mortality as described in the rule. The example presented by the Commenters is based on the analysis conducted during the 2013-2018 rulemaking (Phase II), rather than the current Phase III analysis used for this rule, so it is not applicable to this final rule. See the response to Comment 20 below for more information on how avoidance and mitigation effectiveness are evaluated.
Comment 20:
In a comment on the 2018 HSTT proposed rule, a Commenter stated in regard to the method in which the Navy's post-model calculation considers avoidance specifically (
i.e.,
assuming animals present beyond the range of PTS for the first few pings will be able to avoid it and incur only TTS, which results in a 95 percent reduction in the number of estimated PTS takes predicted by the model), given that sound sources are moving, it may not be until later in an exercise that the animal is close enough to experience PTS, and it is those few close pings that contribute to the potential to experience PTS. An animal being beyond the PTS zone initially has no bearing on whether it will come within close range later during an exercise since both sources and animals are moving. In addition, Navy vessels may move faster than the ability of the animals to evacuate the area. The Navy should have been able to query the dosimeters of the animats to verify whether its 5-percent assumption was valid. The Commenter expressed concerned that this method underestimates the number of PTS takes.
Response:
The consideration of marine mammals avoiding the area immediately around the sound source is provided in the Navy's 2018 technical report titled “Quantitative Analysis for Estimating Acoustic and Explosive Impacts to Marine Mammals and Sea Turtles.” As the Commenter correctly articulates: “For avoidance, the Navy assumed that animals present beyond the range to onset PTS for the first three to four pings are assumed to avoid any additional exposures at levels that could cause PTS. That equated to approximately 5 percent of the total pings or 5 percent of the overall time active; therefore, 95 percent of marine mammals predicted to experience PTS due to sonar and other transducers were instead assumed to experience TTS.” In regard to the comment about vessels moving faster than animals' ability to get out of the way, as discussed in the Navy's 2018 technical report titled “Quantitative Analysis for Estimating Acoustic and Explosive Impacts to Marine Mammals and Sea Turtles,” animats in the Navy's acoustic effects model do not move horizontally or “react” to sound in any way, necessitating the additional step of considering animal avoidance of close-in PTS zones. NMFS independently reviewed this approach and concurs that it is supported by the best available science. Based on a growing body of behavioral response research, animals do in fact avoid the immediate area around sound sources to a distance of a few hundred meters or more depending upon the species. Avoidance to this distance greatly reduces the likelihood of impacts to hearing such as TTS and PTS, respectively. Specifically, the ranges to PTS for most marine mammal groups are within a few tens of meters and the ranges for the most sensitive group, the HF cetaceans, average about 200 m, to a maximum of 270 m in limited cases. Querying the dosimeters of the animats would not produce useful information since, as discussed previously, the animats do not move in the horizontal and are not programmed to “react” to sound or any other stimulus. The Commenter referenced comments that they have previously submitted on the Navy's Gulf of Alaska incidental take regulations and we refer the Commenter to NMFS' responses, which were included in the
Federal Register
document announcing the issuance of the final regulations (82 FR 19572, April 27, 2017).
Underestimated Beaked Whale Injury and Mortality
Comment 21:
In a comment on the 2018 HSTT proposed rule, a Commenter stated that the Navy and NMFS both underestimate take for Cuvier's beaked whales because they are extremely sensitive to sonar. A new study of Cuvier's beaked whales in Southern California exposed to mid and high-power sonar confirmed that they modify their diving behavior up to 100-km away (Falcone
et al.,
2017). The Commenter asserted that this science disproves NMFS' assumption that beaked whales will find suitable habitat nearby within their small range. This modified diving behavior, which was particularly strong when exposed to mid-power sonar, indicates disruption of feeding. Accordingly, impacts on Cuvier's beaked whales could include interference with essential behaviors that will have more than a negligible impact on this species. In addition, Lookouts and shutdowns do not protect Cuvier's beaked whales from Navy sonar because this is a deep-diving species that is difficult to see from ships.
Response:
Takes of Cuvier's beaked whales are not underestimated. The behavioral harassment threshold for beaked whales has two components, both of which consider the sensitivity of beaked whales. First, the biphasic behavioral harassment function for beaked whales, which is based on data on beaked whale responses, has a significantly lower mid-point than other groups and also reflects a significantly higher probability of “take” at lower levels (
e.g.,
close to 15 percent at 120 dB). Additionally, the distance cut-off used for beaked whales is farther than for any other group (50 km, for both the MF1 and MF4 bins, acknowledging the fact that the unpredictability of dipping sonar likely results in takes at greater
distances than other more predictable sources of similar levels). Regarding the referenced article, the Commenter has cited only part of it. The study, which compiles information from multiple studies, found that
shallow
dives were predicted to increase in duration as the distance to both high-and mid-power MFAS sources decreased, beginning at approximately 100 km away and, specifically, the differences only varied from approximately 20 minutes without MFAS to about 24 minutes with MFAS at the closest distance (
i.e.,
the dive time varied from 20 to 24 minutes over the distance of 100 km away to the closest distance measured). Further, the same article predicted that deep dive duration (which is more directly associated with feeding and linked to potential energetic effects) was predicted to increase with proximity to mid-power MFAS from approximately 60 minutes to approximately 90 minutes beginning at around 40 km (10 dives). There were four deep dives exposed to high-power MFAS within 20 km, the distance at which deep dive durations increased with the lower power source types. Other responses to MFAS included deep dives that were shorter than typical and shallower, and instances where there were no observed responses at closer distances. The threshold for Level B harassment is higher than just “any measurable response” and NMFS and the Navy worked closely together to identify behavioral response functions and distance cut-offs that reflect the best available science to identify when marine mammal behavioral patterns will be disrupted to a point where they are abandoned or significantly altered. Further, the take estimate is in no way based on an assumption that beaked whales will always be sighted by Lookouts—and adjustment to account for Lookout effectiveness considers the variable detectability of different species. In this rule, both the take estimate and the negligible impact analysis appropriately consider the sensitivity of, and scale of impacts to (we address impacts to feeding and energetics), Cuvier's (and all) beaked whales. Finally, new passive acoustic monitoring in the HSTT Study Area documents more extensive beaked whale distribution across the entire Study Area, wherever sensors are deployed (Griffiths and Barlow 2016, Rice
et al.
2020).
Comment 22:
In a comment on the 2018 HSTT proposed rule, a Commenter stated that NMFS underestimated serious injury and mortality for beaked whales. They noted the statement in the proposed rule that because a causal relationship between Navy MFAS use and beaked whale strandings has not been established in all instances, and that, in some cases, sonar was considered to be only one of several factors that, in aggregate, may have contributed to the stranding event, NMFS does “not expect strandings, serious injury, or mortality of beaked whales to occur as a result of training activities.” (83 FR 30007). The Commenter asserted that this opinion is inconsistent with best available science and does not take into account the fact that the leading explanation for the mechanism of sonar-related injuries—that whales suffer from bubble growth in organs that is similar to decompression sickness, or “the bends” in human divers—has now been supported by numerous papers. At the same time, the Commenter argued that NMFS fails to seriously acknowledge that sonar can seriously injure or kill marine mammals at distances well beyond those established for permanent hearing loss (83 FR 29916) and dismisses the risk of stranding and other mortality events (83 FR 30007) based on the argument that such effects can transpire only under the same set of circumstances that occurred during known sonar-related events—an assumption that is arbitrary and capricious. In conclusion, the Commenter argued that none of NMFS' assumptions regarding the expected lack of serious injury and mortality for beaked whales are supported by the record, and all lead to an underestimation of impacts.
Response:
The Commenter's characterization of NMFS' analysis is incorrect. NMFS does not disregard the fact that it is possible for naval activities using hull-mounted tactical sonar to contribute to the death of marine mammals in certain circumstances via strandings resulting from behaviorally mediated physiological impacts or other gas-related injuries. NMFS discussed these potential causes and outlined the few cases where active naval sonar (in the United States or, largely, elsewhere) had either potentially contributed to or (as with the Bahamas example) been more definitively causally linked with marine mammal strandings in the proposed rule. As noted, there are a suite of factors that have been associated with these specific cases of strandings directly associated with sonar (steep bathymetry, multiple hull-mounted platforms using sonar simultaneously, constricted channels, strong surface ducts,
etc.
) that are not present together in the HSTT Study Area and during the specified activities (and which the Navy takes care across the world not to operate under without additional monitoring). There have been no documented beaked whale mortalities from Navy activities within the HSTT Study Area. Further, none of the beaked whale strandings causally associated with Navy sonar stranding are in the Pacific. For these reasons, NMFS does not anticipate that the Navy's HSTT training or testing activities will result in beaked whale marine mammal strandings, and none are authorized. Furthermore, ongoing Navy funded beaked whale monitoring at a heavily used training and testing area in SOCAL has not documented mortality or habitat abandonment by beaked whales. Passive acoustic detections of beaked whales have not significantly changed over ten years of monitoring (DiMarzio
et al.,
2018, 2019, 2020). From visual surveys in the area since 2006 there have been repeated sightings of: The same individual beaked whales, beaked whale mother-calf pairs, and beaked whale mother-calf pairs with mothers on their second calf (Schorr
et al.,
2018, 2020). Satellite tracking studies of beaked whale documented high site fidelity to this area even though the study area is located in one of the most used Navy areas in the Pacific (Schorr
et al.,
2018, 2020).
Comment 23:
In a comment on the 2019 HSTT proposed rule, Commenters noted that NMFS did not propose to authorize beaked whale mortalities subsequent to MFA sonar use for any of the Navy's Phase III activities and states that that approach is inconsistent with the tack taken for both TAP I and Phase II activities. The Commenters noted that for the 2013-2018 final rule for HSTT, NMFS authorized up to 10 beaked whale mortality takes during the five-year period of the final rule (78 FR 78153; December 24, 2013). They noted that NMFS justified authorizing those mortalities by stating that, although NMFS does not expect injury or mortality of any beaked whales to occur as a result of active sonar training exercises, there remains the potential for the operation of mid-frequency active sonar to contribute to the mortality of beaked whales (78 FR 78149; December 24, 2013). The Commenters stated that this justification is still applicable. The Commenters state that previously unrecognized sensitivities have been elucidated since the previous final rule was authorized (December 24, 2013), noting that Falcone
et al.,
(2017) indicated that responses of Cuvier's beaked whales to mid-frequency active sonar within and near the Navy's Southern California Anti-submarine
Warfare Range (SOAR) were more pronounced during mid-power (
i.e.,
helicopter-dipping sonar, MF4) than high-power (
i.e.,
hull-mounted sonar, MF1) sonar use. The Commenters state that this indicates lower received levels from a less predictable source caused more marked responses than higher received levels from a predictable source traveling along a seemingly consistent course. The Commenters noted that since multiple species of beaked whales are regularly observed on the Navy's ranges in both Hawaii and Southern California, including its instrumented ranges, those species have been a priority for the Navy's monitoring program and that this indicates that research involving beaked whales continues to be a priority for the Navy and some of the whales' sensitivities to anthropogenic sound are just being discovered. The Commenters assert that until such time that NMFS can better substantiate its conclusion that the Navy's activities do not have the potential to kill beaked whales, taking by mortality should be included in all related rulemakings.
The Commenters asserted that NMFS indicated that steep bathymetry, multiple hull-mounted platforms using sonar simultaneously, constricted channels, and strong surface ducts are not all present together in the HSTT Study Area during the specified activities (83 FR 66882; December 27, 2018), and that NMFS specified that it did not authorize beaked whale mortalities in the 2018 HSTT final rule based on the lack of those factors and the lack of any strandings associated with Navy sonar use in the HSTT Study Area (83 FR 66882; December 27, 2018). The Commenters stated that this does not comport with NMFS' ack
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