Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Military Readiness Activities in the Atlantic Fleet Training and Testing Study Area

ffecting 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 the species or stocks for taking for certain subsistence uses (referred to in shorthand as “mitigation”); and requirements pertaining to the monitoring and reporting of the takings. The MMPA defines “take” to mean to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal. The Preliminary Analysis and Negligible Impact Determination section discusses the definition of “negligible impact.”

The 2004 NDAA (Pub. L. 108-136) amended section 101(a)(5) of the MMPA to remove the “small numbers” and “specified geographical region” provisions and amended the definition of “harassment” as applied to a “military readiness activity” to read as follows (section 3(18)(B) of the MMPA): (i) Any act that injures or has the significant potential to injure a marine mammal or marine mammal stock in the

wild (Level A Harassment); or (ii) Any act that disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing disruption of natural behavioral patterns, including, but not limited to, migration, surfacing, nursing, breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned or significantly altered (Level B Harassment). The 2004 NDAA also amended the MMPA establishing that “[f]or military readiness activity . . . , a determination of `least practicable adverse impact' . . . shall include consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity.” On August 13, 2018, the NDAA for Fiscal Year 2019 (2019 NDAA) (Pub. L. 115-232) amended the MMPA to allow incidental take regulations for military readiness activities to be issued for up to 7 years

ination of `least practicable adverse impact' . . . shall include consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity.” On August 13, 2018, the NDAA for Fiscal Year 2019 (2019 NDAA) (Pub. L. 115-232) amended the MMPA to allow incidental take regulations for military readiness activities to be issued for up to 7 years.

Summary of Major Provisions Within the Proposed Rule

The major provisions of this proposed rule are:

(i) The proposed take of marine mammals by Level A harassment and/or Level B harassment;

(ii) The proposed take of marine mammals by mortality or serious injury (M/SI);

(iii) The proposed use of defined powerdown and shutdown zones (based on activity);

(iv) Proposed measures to reduce the likelihood of vessel strikes;

(v) Proposed activity limitations in certain areas and times that are biologically important ( i.e., for foraging, migration, reproduction) for marine mammals;

(vi) The proposed implementation of a Notification and Reporting Plan (for dead, live stranded, or marine mammals struck by any vessel engaged in military readiness activities); and

(vii) The proposed implementation of a robust monitoring plan to improve our understanding of the environmental effects resulting from the Action Proponents' training and testing activities.

This proposed rule includes an adaptive management component that allows for timely modification of mitigation, monitoring, and/or reporting measures based on new information, when appropriate.

Summary of Request

On May 28, 2024, NMFS received an application from the Action Proponents requesting authorization to take marine mammals, by Level A and Level B harassment, incidental to training and testing (characterized as military readiness activities) including the use of sonar and other transducers, in-water detonations, air guns, and impact and vibratory pile driving and extraction conducted within the AFTT Study Area

024, NMFS received an application from the Action Proponents requesting authorization to take marine mammals, by Level A and Level B harassment, incidental to training and testing (characterized as military readiness activities) including the use of sonar and other transducers, in-water detonations, air guns, and impact and vibratory pile driving and extraction conducted within the AFTT Study Area. In addition, the Action Proponents are requesting authorization to take, by serious injury or mortality, a limited number of several marine mammal species from explosives during training exercises, ship shock trials, and vessel movement during military readiness activities conducted within the AFTT Study Area over the 7-year period of the LOAs. In response to our comments and following information exchange, the Action Proponents submitted a final revised application on August 16, 2024, that we determined was adequate and complete on August 19, 2024. On October 8, 2024, the Action Proponents submitted an updated application to revise take estimates on a subset of Navy activities. On September 20, 2024, we published a notice of receipt (NOR) of application in the Federal Register (89 FR 77106), requesting comments and information related to the Action Proponents' request for 30 days. During the 30-day public comment period on the NOR, we did not receive any public comments. On January 21, 2025, the Action Proponents submitted an updated application that removed ship shock trials and estimated take associated with that activity in Key West and within the Virginia Capes (VACAPES) Range Complex and, on February 13, 2025, the Action Proponents submitted an updated application containing minor revisions.

NMFS has previously promulgated incidental take regulations pursuant to the MMPA relating to similar military readiness activities in AFTT

iness requirements. These proposed regulations would cover military readiness activities in the AFTT Study Area that would occur for a 7-year period following the expiration of the existing MMPA authorization on November 13, 2025.

Description of Proposed Activity

Overview

The Action Proponents request authorization to take marine mammals incidental to conducting military readiness activities. The Action Proponents have determined that acoustic and explosives stressors are most likely to result in take of marine mammals that could rise to the level of harassment, and take by serious injury or mortality may result from vessel movement, explosive use, and ship shock trials. Detailed descriptions of these activities are provided in chapter 2 of the 2024 AFTT Draft Supplemental Environmental Impact Statement (EIS)/Overseas EIS (OEIS) (2024 AFTT Draft Supplemental EIS/OEIS) ( https://www.nepa.navy.mil/aftteis/ ) and in the Action Proponents' application ( https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities ) and are summarized here.

The Navy's statutory mission is to organize, train, equip, and maintain combat-ready naval forces for the peacetime promotion of the national security interests and prosperity of the United States, and for prompt and sustained combat incident to operations essential to the prosecution of a naval campaign. These missions are mandated by Federal law (10 U.S.C. 8062 and 10 U.S.C. 8063), which requires the readiness of the naval forces of the United States. The Navy executes this responsibility by establishing and executing at-sea training and testing, often in designated operating areas (OPAREA) and testing and training ranges. The Navy must be able to access and utilize these areas and associated sea and air space to develop and maintain skills for conducting naval operations

), which requires the readiness of the naval forces of the United States. The Navy executes this responsibility by establishing and executing at-sea training and testing, often in designated operating areas (OPAREA) and testing and training ranges. The Navy must be able to access and utilize these areas and associated sea and air space to develop and maintain skills for conducting naval operations. The Navy's testing activities ensure naval forces are equipped with well-maintained systems that take advantage of the latest technological advances. The Navy's research and acquisition community conducts military readiness activities that involve testing. The Navy tests vessels, aircraft, weapons, combat systems, sensors, and

related equipment, and conducts scientific research activities to achieve and maintain military readiness.

The mission of the Coast Guard is to ensure the maritime safety, security, and stewardship of the United States. To advance this mission, the Coast Guard must ensure its personnel can qualify and train jointly with, and independently of, the Navy and other services in the effective and safe operational use of Coast Guard vessels, aircraft, and weapons under realistic conditions. These activities help ensure the Coast Guard can safely assist in the defense of the United States by protecting the United States' maritime safety, security, and natural resources in accordance with its national defense mission (14 U.S.C. 102). Coast Guard training activities are described in more detail in appendix C of the 2024 AFTT Draft Supplemental EIS/OEIS and in the Action Proponents' application, and are summarized below.

Dates and Duration

The specified activities would occur at any time during the 7-year period of validity of the regulations. The proposed number of military readiness activities are described in the Detailed Description of the Specified Activity section (table 4 through table 9)

s one OPAREA: Navy Cherry Point 19,000 nmi 2 of special use airspace. Jacksonville Range Complex (JAX RC) 520 miles along the coast from North Carolina to Florida, from the shoreline to roughly 250 nmi seaward 50,000 nmi 2 of sea and undersea space. Includes three OPAREAs: Charleston, Jacksonville and Cape Canaveral. Includes the Undersea Warfare Training Range 64,000 nmi 2 of special use airspace. Naval Surface Warfare Center, Carderock Division, South Florida Ocean Measurement Facility Testing Range (SFOMF) Located adjacent to the Port Everglades entrance channel in Fort Lauderdale, Florida; out to roughly 25 nmi from shore 500 nmi 2 of sea and undersea space No associated special use airspace. Key West Range Complex Off the southwestern coast of mainland Florida and along the southern Florida Keys, extending into the Gulf of America and the Straits of Florida 8,000 nmi 2 of sea and undersea space south of Key West. Includes one OPAREA: Key West 23,000 nmi 2 of special use airspace. Naval Surface Warfare Center, Panama City Division Testing Area Off the panhandle of Florida and Alabama, extending from the shoreline 120 nmi seaward and includes St. Andrew Bay 23,000 nmi 2 of sea and undersea space. Includes two OPAREAs: Panama City and Pensacola 23,000 nmi 2 of special use airspace. Gulf Range Complex (Gulf RC) Includes geographically separated areas throughout the Gulf of America 20,000 nmi 2 of sea and undersea space. Includes four OPAREAs: Panama City, Pensacola, New Orleans, and Corpus Christi 43,000 nmi 2 of special use airspace. Note: nmi = nautical mile, nmi 2 = square nautical mile, areas and distances of locations, sea and undersea space, and airspace are approximations. Table 2—AFTT Study Area Inshore Locations Name Associated inshore waters Northeast Range Complexes Inshore Thames River, Narragansett Bay, Rhode Island Sound, Block Island Sound. Virginia Capes Range Complex (VACAPES RC) Inshore Lower Chesapeake Bay, James River and tributaries, Broad Bay, York River

l mile, areas and distances of locations, sea and undersea space, and airspace are approximations. Table 2—AFTT Study Area Inshore Locations Name Associated inshore waters Northeast Range Complexes Inshore Thames River, Narragansett Bay, Rhode Island Sound, Block Island Sound. Virginia Capes Range Complex (VACAPES RC) Inshore Lower Chesapeake Bay, James River and tributaries, Broad Bay, York River. Jacksonville Range Complex (JAX RC) Inshore Blount Island, Southeast Kings Bay, Cooper River, St. Johns River, Port Canaveral. Key West Range Complex Inshore Truman Harbor, Demolition Key. Gulf Range Complex (Gulf RC) Inshore St. Andrew Bay, Atchafalaya Bay, Atchafalaya River, Lake Borgne, Pascagoula River, Mobile Bay. Note: The Gulf Range Complex Inshore includes geographically separated areas throughout the Gulf of America. Table 3—AFTT Study Area Ports and Piers Pierside locations Civilian ports Coast Guard locations Portsmouth Naval Shipyard Bath, ME Southwest Harbor, ME Naval Submarine Base New London Boston, MA Boston, MA Naval Station Newport Earle, NJ Cape Cod, MA Naval Station Norfolk Delaware Bay, DE New London, CT * Joint Expeditionary Base Little Creek Fort Story Hampton Roads, VA New Haven CT * Norfolk Naval Shipyard Morehead City, NC Newport, RI * Naval Submarine Base Kings Bay Wilmington, NC Montauk, NY Naval Station Mayport Kings Bay, GA Staten Island, NY * Port Canaveral Savannah, GA Atlantic City, NJ Mayport, FL Chesapeake, VA Port Canaveral, FL Virginia Beach, VA * Tampa, FL Portsmouth, VA* Pascagoula, MS Elizabeth City, NC Gulfport, MS Charleston, SC * Beaumont, TX Mayport, FL * Corpus Christi, TX Cape Canaveral, FL * Fort Pierce, FL * Dania, FL * Miami, FL * Key West, FL * St. Petersburg, FL * Pensacola, FL * Opa Locka, FL New Orleans, LA Houston, TX Corpus Christi, TX Note: CT: Connecticut; FL: Florida; GA: Georgia; LA: Louisiana; MA: Massachusetts; ME: Maine; MS: Mississippi; NC: North Carolina; NJ: New Jersey; NY: New York; RI: Rhode Island; SC: South Carolina; TX: Texas; VA: Virginia

X Cape Canaveral, FL * Fort Pierce, FL * Dania, FL * Miami, FL * Key West, FL * St. Petersburg, FL * Pensacola, FL * Opa Locka, FL New Orleans, LA Houston, TX Corpus Christi, TX Note: CT: Connecticut; FL: Florida; GA: Georgia; LA: Louisiana; MA: Massachusetts; ME: Maine; MS: Mississippi; NC: North Carolina; NJ: New Jersey; NY: New York; RI: Rhode Island; SC: South Carolina; TX: Texas; VA: Virginia. * Indicates Coast Guard cutter stations. Detailed Description of the Specified Activity

The Action Proponents propose to conduct military readiness activities within the AFTT Study Area and have been conducting military readiness activities in the Study Area for well over a century and with active sonar for over 70 years. The tempo and types of military readiness activities have fluctuated due to the introduction of new technologies, the evolving nature of international events, advances in warfighting doctrine and procedures, and changes in force structure (organization of vessels, weapons, and personnel). Such developments influenced the frequency, duration, intensity, and location of required military readiness activities.

Primary Mission Areas

The Navy categorizes their activities into functional warfare areas called primary mission areas, while the Coast Guard categorizes their activities as operational mission programs. For the Navy, these activities generally fall into the following five primary mission areas (Coast Guard mission areas are discussed below). The Navy mission areas with activities that may result in incidental take of marine mammals (and stressors associated with training and testing activities within those mission areas) include the following:

(i) Amphibious warfare (in-water detonations);

(ii) Anti-submarine warfare (sonar and other transducers, in-water detonations);

(iii) Expeditionary warfare (in-water detonations, pile driving and extraction);

(iv) Mine warfare (sonar and other transducers, in-water detonations);

anti-submarine warfare is to locate, neutralize, and defeat hostile submarine forces that threaten Navy forces. Anti-submarine warfare is based on the principle that surveillance and attack aircraft, ships, and submarines all search for hostile submarines. These forces operate together or independently to gain early warning and detection and to localize, track, target, and attack submarine threats.

Anti-submarine warfare training addresses basic skills such as detecting and classifying submarines, as well as evaluating sounds to distinguish between enemy submarines and friendly submarines, ships, and marine life. More advanced training integrates the full spectrum of anti-submarine warfare from detecting and tracking a submarine to attacking a target using either exercise torpedoes ( i.e., torpedoes that do not contain a warhead) or simulated weapons. These integrated anti-submarine warfare training exercises are conducted in coordinated, at-sea training events involving submarines, ships, and aircraft.

Testing of anti-submarine warfare systems is conducted to develop new technologies and assess weapon performance and operability with new systems and platforms, such as unmanned systems. Testing uses ships, submarines, and aircraft to demonstrate capabilities of torpedoes, missiles, countermeasure systems, and underwater surveillance and communications systems. Tests may be conducted as part of a large-scale fleet training event involving submarines, ships, fixed-wing aircraft, and helicopters. These integrated training events offer opportunities to conduct research and acquisition activities and to train aircrew in the use of new or newly enhanced systems during a large-scale, complex exercise.

Expeditionary Warfare—

The mission of expeditionary warfare is to provide security and surveillance in the littoral (at the shoreline), riparian (along a river), or coastal environments

ters. These integrated training events offer opportunities to conduct research and acquisition activities and to train aircrew in the use of new or newly enhanced systems during a large-scale, complex exercise.

Expeditionary Warfare—

The mission of expeditionary warfare is to provide security and surveillance in the littoral (at the shoreline), riparian (along a river), or coastal environments. Expeditionary warfare is wide ranging and includes defense of harbors, operation of remotely operated vehicles, defense against swimmers, and boarding/seizure operations.

Expeditionary warfare training activities include Navy, Marine Corps, and Coast Guard underwater construction team training, dive and salvage operations, and insertion/extraction via air, surface, and subsurface platforms.

Mine Warfare—

The mission of mine warfare is to detect, classify, and avoid or neutralize (disable) mines to protect U.S. ships and submarines, and to maintain free access to ports and shipping lanes. Mine warfare training for the Navy and Coast Guard falls into two primary categories: mine detection and classification, and mine countermeasure and neutralization. Mine warfare also includes offensive mine laying to gain control of or deny the enemy access to sea space. Naval mines can be laid by ships, submarines, UUVs, or aircraft.

Mine warfare neutralization training includes exercises in which aircraft, ships, submarines, underwater vehicles, unmanned vehicles, or marine mammal detection systems search for mine shapes. Personnel train to destroy or disable mines by attaching underwater explosives to or near the mine or using remotely operated vehicles to destroy the mine.

Mine warfare testing is similar to training but focuses on the development of mine warfare systems to improve sonar, laser, and magnetic detectors intended to hunt, locate, and record the positions of mines for avoidance or subsequent neutralization

y and missile exercises, air-to-surface gunnery, bombing, and missile exercises, submarine torpedo launch events, other munitions against surface targets, and amphibious operations in a contested environment.

Testing of weapons used in surface warfare is conducted to develop new technologies and to assess weapon performance and operability with new systems and platforms, such as unmanned systems. Tests include various air-to-surface guns and missiles, surface-to-surface guns and missiles, and bombing tests. Testing events may be integrated into training activities to test aircraft or aircraft systems in the delivery of ordnance on a surface target. In most cases the tested systems are used in the same manner in which they are used for training activities.

Overview of Training Activities Within the Study Area

The Action Proponents routinely train in the AFTT Study Area in preparation for national defense missions. Training activities and exercises covered in this proposed rule are briefly described below and in more detail within appendix A (Activity Descriptions) of the 2024 AFTT Draft Supplemental EIS/OEIS. The description, annual number of activities, and location of each training activity are provided by stressor category in table 4, table 5, and table 6. Each training activity described meets a requirement that can be traced ultimately to requirements set forth by the National Command Authority.

Within the Navy, a major training exercise (MTE) is comprised of multiple “unit-level” exercises conducted by several units operating together while commanded and controlled by a single commander (these units are collectively referred to as carrier and expeditionary strike groups). These exercises typically employ an exercise scenario developed to train and evaluate the strike group in tactical naval tasks

upplemental EIS/OEIS. Table 5 describes the proposed Navy training activities analyzed within the AFTT Study Area while table 6 describes the proposed Coast Guard training activities analyzed within the AFTT Study Area. In addition to participating in Navy-led exercises, Coast Guard training activities include unit-level activities conducted independently of, and not in coordination with, the Navy.

Table 4—Major Training Exercises and Integrated/Coordinated Training Activities Analyzed Within the AFTT Study Area Training type Exercise group Description Scale Duration Location (range complex) Exercise examples Typical hull-mounted sonar per event Major Training Exercise Large Integrated ASW Larger-scale, longer duration integrated ASW exercises Greater than 6 surface ASW units (up to 30 with the largest exercises), 2 or more submarines, multiple ASW aircraft Generally greater than 10 days Jacksonville Range Complex, Navy Cherry Point Range Complex, Virginia Capes Range Complex COMPTUEX <500 hours. Major Training Exercise Medium Integrated ASW Medium-scale, medium duration integrated ASW exercises Approximately 3-8 surface ASW units, at least 1 submarine, multiple ASW aircraft Generally 4-10 days Jacksonville Range Complex, Navy Cherry Point Range Complex, Virginia Capes Range Complex Sustainment/Task Force Exercise 100-300 hours. Integrated/Coordinated Training Small Integrated ASW Small-scale, short duration integrated ASW exercises Approximately 3-6 surface ASW units, 2 dedicated submarines, 2-6 ASW aircraft Generally less than 5 days Jacksonville Range Complex, Navy Cherry Point Range Complex, Virginia Capes Range Complex SWATT, NUWTAC 50-100 hours. Integrated/Coordinated Training Medium Coordinated ASW Medium-scale, medium duration, coordinated ASW exercises Approximately 2-4 surface ASW units, possibly a submarine, 2-5 ASW aircraft Generally 3-10 days Jacksonville Range Complex, Navy Cherry Point Range Complex, Virginia Capes Range Complex ASW Tactical Development Exercise <100 hours

lex. Acoustic Major Training Exercise—Medium Integrated ASW Sustainment/Task Force Exercise Aircraft carrier and carrier air wing integrates with surface and submarine units in a challenging multi-threat operational environment to maintain ability to deploy. LFH, MFM, MFH, MF1, MF1C, Broadband (MF to HF) 2 14 Jacksonville Range Complex, Navy Cherry Point Range Complex, Virginia Capes Range Complex. Acoustic Small Integrated ASW Training Navy Undersea Warfare Training Assessment Course Multiple ships, aircraft, and submarines integrate the use of their sensors, including sonobuoys, to search for, detect, classify, localize, and track a threat submarine. LFH, MFM, MFH, MF1, MF1C, Broadband (MF to HF) 2 14 Jacksonville Range Complex, Navy Cherry Point Range Complex, Virginia Capes Range Complex. Acoustic Small Integrated ASW Training Surface Warfare Advanced Tactical Training Multiple ships and aircraft coordinate the use of sensors, including sonobuoys, to search, detect, and track a threat submarine. Surface Warfare Advanced Tactical Training (SWATT) exercises are not dedicated anti-submarine warfare exercises and involve multiple warfare areas. LFH, MFM, MFH, MF1, MF1C, Broadband (MF to HF) 2 14 Jacksonville Range Complex, Navy Cherry Point Range Complex, Virginia Capes Range Complex. Acoustic Medium Coordinated ASW Training Tactical Development Exercise Multiple ships, aircraft, and submarines coordinate their efforts to search for, detect, and track submarines with the use of all sensors. Anti-Submarine Warfare Tactical Development Exercise is a dedicated anti-submarine warfare exercise. MFM, MFH, MF1, MF1C, Broadband (MF to HF) 1 7 Jacksonville Range Complex. Acoustic Medium Coordinated ASW Training Tactical Development Exercise Multiple ships, aircraft, and submarines coordinate their efforts to search for, detect, and track submarines with the use of all sensors. Anti-Submarine Warfare Tactical Development Exercise is a dedicated anti-submarine warfare exercise

editionary Unit Composite Training Unit Exercise Amphibious Ready Group exercises are conducted to validate the Marine Expeditionary Unit's readiness for deployment and include small boat raids; visit, board, search, and seizure training; helicopter and mechanized amphibious raids; and non-combatant evacuation operations. LFH, MFM, MFH, MF1, Broadband (MF to HF) 1 7 Navy Cherry Point Range Complex. Explosive Amphibious Warfare Amphibious Operations in a Contested Environment Navy and Marine Corps forces conduct operations in coastal and offshore waterways against air, surface, and subsurface threats. E1, E2, E3, E6, E9, E10 45 315 Navy Cherry Point Range Complex. Explosive Amphibious Warfare Amphibious Operations in a Contested Environment Navy and Marine Corps forces conduct operations in coastal and offshore waterways against air, surface, and subsurface threats. E1, E2, E3, E6, E9, E10 12 84 Virginia Capes Range Complex. Acoustic Anti-Submarine Warfare Anti-Submarine Warfare Torpedo Exercise—Helicopter Helicopter crews search for, track, and detect submarines. Recoverable air launched torpedoes are employed against submarine targets. MFM, MFH, HFH, Broadband (MF to HF) 14 98 Jacksonville Range Complex. Acoustic Anti-Submarine Warfare Anti-Submarine Warfare Torpedo Exercise—Helicopter Helicopter crews search for, track, and detect submarines. Recoverable air launched torpedoes are employed against submarine targets. MFM, MFH, HFH, Broadband (MF to HF) 4 28 Virginia Capes Range Complex. Acoustic Anti-Submarine Warfare 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. MFM, HFH, Broadband (MF to HF) 14 98 Jacksonville Range Complex. Acoustic Anti-Submarine Warfare Anti-Submarine Warfare Torpedo Exercise—Maritime Patrol Aircraft Maritime patrol aircraft crews search for, track, and detect submarines

k, and detect submarines. Exercise torpedoes may be used during this event. MFH, MF1, MF1C, Broadband (MF to HF) 55 385 Other AFTT Areas. Acoustic Anti-Submarine Warfare Anti-Submarine Warfare Tracking Exercise—Ship Surface ship crews search for, track, and detect submarines. Exercise torpedoes may be used during this event. MFH, MF1, MF1C, Broadband (MF to HF) 120 840 Virginia Capes Range Complex. Acoustic Anti-Submarine Warfare Anti-Submarine Warfare Tracking Exercise—Submarine Submarine crews search for, track, and detect submarines. LFH, MFH, HFH 13 91 Jacksonville Range Complex. Acoustic Anti-Submarine Warfare Anti-Submarine Warfare Tracking Exercise—Submarine Submarine crews search for, track, and detect submarines. LFH, MFH, HFH 1 7 Navy Cherry Point Range Complex. Acoustic Anti-Submarine Warfare Anti-Submarine Warfare Tracking Exercise—Submarine Submarine crews search for, track, and detect submarines. LFH, MFH, HFH 18 126 Northeast Range Complexes. Acoustic Anti-Submarine Warfare Anti-Submarine Warfare Tracking Exercise—Submarine Submarine crews search for, track, and detect submarines. LFH, MFH, HFH 46 308 Other AFTT Areas. Acoustic Anti-Submarine Warfare Anti-Submarine Warfare Tracking Exercise—Submarine Submarine crews search for, track, and detect submarines. LFH, MFH, HFH 6 42 Virginia Capes Range Complex. Acoustic Expeditionary Warfare Port Damage Repair Navy and Coast Guard Expeditionary forces train to repair critical port facilities. Pile driving 4 28 Gulfport, MS. Acoustic Mine Warfare Airborne Mine Countermeasures—Mine Detection Helicopter aircrew detect mines using towed or laser mine detection systems. HFH 290 2,030 Gulf Range Complex. Acoustic Mine Warfare Airborne Mine Countermeasures—Mine Detection Helicopter aircrew detect mines using towed or laser mine detection systems. HFH 275 1,925 Jacksonville Range Complex. Acoustic Mine Warfare Airborne Mine Countermeasures—Mine Detection Helicopter aircrew detect mines using towed or laser mine detection systems

owed or laser mine detection systems. HFH 290 2,030 Gulf Range Complex. Acoustic Mine Warfare Airborne Mine Countermeasures—Mine Detection Helicopter aircrew detect mines using towed or laser mine detection systems. HFH 275 1,925 Jacksonville Range Complex. Acoustic Mine Warfare Airborne Mine Countermeasures—Mine Detection Helicopter aircrew detect mines using towed or laser mine detection systems. HFH 187 1,309 Key West Range Complex. Acoustic Mine Warfare Airborne Mine Countermeasures—Mine Detection Helicopter aircrew detect mines using towed or laser mine detection systems. HFH 321 2,247 Navy Cherry Point Range Complex. Acoustic Mine Warfare Airborne Mine Countermeasures—Mine Detection Helicopter aircrew detect mines using towed or laser mine detection systems. HFH 1,420 9,940 Virginia Capes Range Complex. Acoustic Mine Warfare Civilian Port Defense—Homeland Security Anti-Terrorism/Force Protection Exercises Coast Guard and Navy Maritime security personnel train to protect civilian ports and harbors against enemy efforts to interfere with access to those ports. MFH, HFM, HFH 0-1 4 Boston, MA; Beaumont, TX; Corpus Christi, TX; Delaware Bay, DE; Earle, NJ; Hampton Roads, VA; Kings Bay, GA; Mayport, FL; Morehead City, NC; Port Canaveral, FL; Savannah, GA; Tampa, FL; Wilmington, NC. Acoustic and Explosive Mine Warfare Mine Countermeasures—Mine Neutralization—Remotely Operated Vehicles Ship, small boat, and helicopter crews locate and disable mines using remotely operated underwater vehicles. All events include acoustic sources, only a fraction involve explosives. HFM, E4 * 66 * 462 Gulf Range Complex. Acoustic and Explosive Mine Warfare Mine Countermeasures—Mine Neutralization—Remotely Operated Vehicles Ship, small boat, and helicopter crews locate and disable mines using remotely operated underwater vehicles. All events include acoustic sources, only a fraction involve explosives. HFM, E4 36 252 Jacksonville Range Complex

ly a fraction involve explosives. HFM, E4 * 66 * 462 Gulf Range Complex. Acoustic and Explosive Mine Warfare Mine Countermeasures—Mine Neutralization—Remotely Operated Vehicles Ship, small boat, and helicopter crews locate and disable mines using remotely operated underwater vehicles. All events include acoustic sources, only a fraction involve explosives. HFM, E4 36 252 Jacksonville Range Complex. Acoustic and Explosive Mine Warfare Mine Countermeasures—Mine Neutralization—Remotely Operated Vehicles Ship, small boat, and helicopter crews locate and disable mines using remotely operated underwater vehicles. All events include acoustic sources, only a fraction involve explosives. HFM, E4 10 70 Key West Range Complex. Acoustic and Explosive Mine Warfare Mine Countermeasures—Mine Neutralization—Remotely Operated Vehicles Ship, small boat, and helicopter crews locate and disable mines using remotely operated underwater vehicles. All events include acoustic sources, only a fraction involve explosives. HFM, E4 * 36 * 252 Navy Cherry Point Range Complex. Acoustic and Explosive Mine Warfare Mine Countermeasures—Mine Neutralization—Remotely Operated Vehicles Ship, small boat, and helicopter crews locate and disable mines using remotely operated underwater vehicles. All events include acoustic sources, only a fraction involve explosives. HFM, E4 * 315 * 2,205 Virginia Capes Range Complex. Acoustic Mine Warfare Mine Countermeasures—Ship Sonar Ship crews detect and avoid mines while navigating restricted areas or channels using active sonar. HFH 22 * 462 Gulf Range Complex. Acoustic Mine Warfare Mine Countermeasures—Ship Sonar Ship crews detect and avoid mines while navigating restricted areas or channels using active sonar. HFH 53 252 Jacksonville Range Complex. Acoustic Mine Warfare Mine Countermeasures—Ship Sonar Ship crews detect and avoid mines while navigating restricted areas or channels using active sonar. HFH 53 70 Virginia Capes Range Complex

Navy Cherry Point Range Complex. Explosive Surface Warfare Gunnery Exercise Surface-to-Surface Ship Large-Caliber Surface ship crews fire large-caliber guns at surface targets. E3, E5 * 9 * 63 Other AFTT Areas. Explosive Surface Warfare Gunnery Exercise Surface-to-Surface Ship Large-Caliber Surface ship crews fire large-caliber guns at surface targets. E3, E5 * 63 *441 Virginia Capes Range Complex. Explosive Surface Warfare 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. E10 2 14 Jacksonville Range Complex. Explosive Surface Warfare 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. E10 2 14 Virginia Capes Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface—Rocket Helicopter aircrew fire both precision-guided and unguided rockets at surface targets. E3 10 70 Gulf Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface—Rocket Helicopter aircrew fire both precision-guided and unguided rockets at surface targets. E3 115 805 Jacksonville Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface—Rocket Helicopter aircrew fire both precision-guided and unguided rockets at surface targets. E3 15 105 Navy Cherry Point Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface—Rocket Helicopter aircrew fire both precision-guided and unguided rockets at surface targets. E3 100 700 Virginia Capes Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface Fixed-wing and helicopter aircrew fire air-to-surface missiles at surface targets. E6, E8, E9 81 567 Jacksonville Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface Fixed-wing and helicopter aircrew fire air-to-surface missiles at surface targets. E6 8 56 Key West Range Complex

E3 100 700 Virginia Capes Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface Fixed-wing and helicopter aircrew fire air-to-surface missiles at surface targets. E6, E8, E9 81 567 Jacksonville Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface Fixed-wing and helicopter aircrew fire air-to-surface missiles at surface targets. E6 8 56 Key West Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface Fixed-wing and helicopter aircrew fire air-to-surface missiles at surface targets. E6 72 504 Navy Cherry Point Range Complex. Explosive Surface Warfare Missile Exercise Air-to-Surface Fixed-wing and helicopter aircrew fire air-to-surface missiles at surface targets. E6, E8, E9 83 581 Virginia Capes Range Complex. Explosive Surface Warfare Missile Exercise Surface-to-Surface Surface ship crews defend against surface threats (ships or small boats) and engage them with missiles. E6, E9 19 133 Jacksonville Range Complex. Explosive Surface Warfare Missile Exercise Surface-to-Surface Surface ship crews defend against surface threats (ships or small boats) and engage them with missiles. E6, E9 15 105 Virginia Capes Range Complex. Acoustic and Explosive Surface Warfare Sinking Exercise Aircraft, ship, cutter, 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 ordnance. HFH, E5, E8, E9, E11 1 7 SINKEX Box. Acoustic Other Training Activities Submarine Navigation Submarine crews operate sonar for navigation and detection while transiting into and out of port during reduced visibility. MFH 29 203 Jacksonville Range Complex. Acoustic Other Training Activities Submarine Navigation Submarine crews operate sonar for navigation and detection while transiting into and out of port during reduced visibility. MFH 169 1,183 Northeast Range Complexes

sea. MFH 66 462 NSB New London. Acoustic Other Training Activities Submarine Sonar Maintenance and Systems Checks Maintenance of submarine sonar and other system checks are conducted pierside or at sea. MFH 12 84 Other AFTT Areas. Acoustic Other Training Activities Submarine Sonar Maintenance and Systems Checks Maintenance of submarine sonar and other system checks are conducted pierside or at sea. MFH 34 238 Virginia Capes Range Complex. Acoustic Other Training Activities Submarine Sonar Maintenance and Systems Checks Maintenance of submarine sonar and other system checks are conducted pierside or at sea. MFH 34 238 NS Norfolk. Acoustic Other Training Activities Submarine Under Ice Certification Submarine crews operate sonar while transiting under ice. Ice conditions are simulated during training and certification events. HFH 3 21 Jacksonville Range Complex. Acoustic Other Training Activities Submarine Under Ice Certification Submarine crews operate sonar while transiting under ice. Ice conditions are simulated during training and certification events. HFH 3 21 Navy Cherry Point Range Complex. Acoustic Other Training Activities Submarine Under Ice Certification Submarine crews operate sonar while transiting under ice. Ice conditions are simulated during training and certification events. HFH 9 63 Northeast Range Complexes. Acoustic Other Training Activities Submarine Under Ice Certification Submarine crews operate sonar while transiting under ice. Ice conditions are simulated during training and certification events. HFH 9 63 Virginia Capes Range Complex. Acoustic Other Training Activities Surface Ship Sonar Maintenance and Systems Checks Maintenance of surface ship sonar and other system checks are conducted pierside or at sea. MF1, MF1K 50 350 Jacksonville Range Complex. Acoustic Other Training Activities Surface Ship Sonar Maintenance and Systems Checks Maintenance of surface ship sonar and other system checks are conducted pierside or at sea. MF1, MF1K 50 350 NS Mayport

tivities Surface Ship Sonar Maintenance and Systems Checks Maintenance of surface ship sonar and other system checks are conducted pierside or at sea. MF1, MF1K 50 350 Jacksonville Range Complex. Acoustic Other Training Activities Surface Ship Sonar Maintenance and Systems Checks Maintenance of surface ship sonar and other system checks are conducted pierside or at sea. MF1, MF1K 50 350 NS Mayport. Acoustic Other Training Activities Surface Ship Sonar Maintenance and Systems Checks Maintenance of surface ship sonar and other system checks are conducted pierside or at sea. MF1, MF1K 120 840 Navy Cherry Point Range Complex. Acoustic Other Training Activities Surface Ship Sonar Maintenance and Systems Checks Maintenance of surface ship sonar and other system checks are conducted pierside or at sea. MF1, MF1K 175 1,225 NS Norfolk. Acoustic Other Training Activities Surface Ship Sonar Maintenance and Systems Checks Maintenance of surface ship sonar and other system checks are conducted pierside or at sea. MF1, MF1K 18 126 Other AFTT Areas. Acoustic Other Training Activities Surface Ship Sonar Maintenance and Systems Checks Maintenance of surface ship sonar and other system checks are conducted pierside or at sea. MF1, MF1K 175 1,225 Virginia Capes Range Complex. Acoustic Other Training Activities 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. MFH, HFL, HFM, VHFL, VHFM, VHFH, Broadband (MF to HF), Broadband (HF to VHF) 10 70 Gulf Range Complex. Acoustic Other Training Activities Unmanned Underwater Vehicle Training—Certification and Development Unmanned underwater vehicle certification involves training with unmanned platforms to ensure submarine crew proficiency

activities include explosive ordnance. Table 6—Proposed Coast Guard Training Activities Analyzed Within the AFTT Study Area Stressor category Activity type Activity name Description Source bin Number of activities 1-year Number of activities 7-year Location Explosive Surface Warfare Gunnery Exercise Surface-to-Surface Ship Large-Caliber Surface ship crews fire large-caliber guns at surface targets. E3 * 29 203 Gulf Range complex. Explosive Surface Warfare Gunnery Exercise Surface-to-Surface Ship Large-Caliber Surface ship crews fire large-caliber guns at surface targets. E3 15 105 Jacksonville Range Complex. Explosive Surface Warfare Gunnery Exercise Surface-to-Surface Ship Large-Caliber Surface ship crews fire large-caliber guns at surface targets. E3 10 70 Navy Cherry Point Range Complex. Explosive Surface Warfare Gunnery Exercise Surface-to-Surface Ship Large-Caliber Surface ship crews fire large-caliber guns at surface targets. E3 * 15 105 Northeast Range Complexes. Explosive Surface Warfare Gunnery Exercise Surface-to-Surface Ship Large-Caliber Surface ship crews fire large-caliber guns at surface targets. E3 * 20 140 Virginia Capes Range Complex. Acoustic Surface Warfare 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. MFH, HFL, HFM, VHFL, VHFM, VHFH, Broadband (MF to HF), Broadband (HF to VHF) 10 70 Gulf Range Complex. Acoustic Surface Warfare 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

lf Range Complex. Acoustic Surface Warfare 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. MFH, HFL, HFM, VHFL, VHFM, VHFH, Broadband (MF to HF), Broadband (HF to VHF) 10 70 Jacksonville Range Complex. Acoustic Surface Warfare 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. MFH, HFL, HFM, VHFL, VHFM, VHFH, Broadband (MF to HF), Broadband (HF to VHF) 10 70 Navy Cherry Point Range Complex. Acoustic Surface Warfare 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. MFH, HFL, HFM, VHFL, VHFM, VHFH, Broadband (MF to HF), Broadband (HF to VHF) 20 140 Virginia Capes Range Complex. Acoustic Surface Warfare 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. MFH, HFL, HFM, VHFL, VHFM, VHFH, Broadband (MF to HF), Broadband (HF to VHF) 20 140 Virginia Capes Range Complex Inshore

erwater 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. MFH, HFL, HFM, VHFL, VHFM, VHFH, Broadband (MF to HF), Broadband (HF to VHF) 20 140 Virginia Capes Range Complex Inshore. Note: The Gulf Range Complex includes geographically separated areas throughout the Gulf of America. * Only a small subset of these activities include explosive ordnance. Overview of Testing Activities Within the Study Area

While this proposed rule includes an evaluation of proposed training activities by both the Navy and Coast Guard, all testing activities evaluated in this proposed rule would only be conducted by the Navy. The Navy's research and acquisition community engages in a broad spectrum of testing activities, some of which ultimately support both Action Proponents. These activities include, but are not limited to, basic and applied scientific research and technology development; testing, evaluation, and maintenance of systems ( e.g., missiles, radar, and sonar) and platforms ( e.g., surface ships, submarines, and aircraft); and acquisition of systems and platforms to support Navy missions and give a technological edge over adversaries. The individual commands within the research and acquisition community included in the application are Naval Air Systems Command (NAVAIR), Naval Sea Systems Command (NAVSEA), and the Office of Naval Research (ONR).

The Action Proponents operate in an ever-changing strategic, tactical, financially-constrained, and time-constrained environment. Testing activities occur in response to emerging science or fleet operational needs. For example, future Navy studies to develop a better understanding of ocean currents may be designed based on advancements made by non-government researchers not yet published in the scientific literature

cultural resources.

Because standard operating procedures are essential to safety and mission success, the Action Proponents consider them to be part of the proposed activities and have included them in the environmental analysis. Standard operating procedures that are recognized as providing a potential secondary benefit on marine mammals during training and testing activities are noted below.

(i) Vessel safety;

(ii) Weapons firing safety;

(iii) Target deployment safety;

(iv) Towed in-water device safety;

(v) Pile driving safety; and

(vi) Coastal zones.

Standard operating procedures (which are implemented regardless of their secondary benefits) are different from mitigation measures (which are designed entirely for the purpose of avoiding or reducing impacts). Information on mitigation measures is provided in the Proposed Mitigation Measures section below. Additional information on standard operating procedures is discussed in more detail in appendix A (Activity Descriptions) of

the 2024 AFTT Draft Supplemental EIS/OEIS.

Description of Stressors

The Action Proponents use a variety of sensors, platforms, weapons, and other devices, and military readiness activities using these systems may introduce sound and energy into the environment. The proposed military readiness activities were evaluated to identify specific components that would act as stressors by having direct or indirect impacts on marine mammals and their habitat. This analysis included identification of the spatial variation of the identified stressors. The following subsections describe the acoustic and explosive stressors for marine mammals and their habitat within the AFTT Study Area. Each description contains a list of activities that may generate the stressor

ld act as stressors by having direct or indirect impacts on marine mammals and their habitat. This analysis included identification of the spatial variation of the identified stressors. The following subsections describe the acoustic and explosive stressors for marine mammals and their habitat within the AFTT Study Area. Each description contains a list of activities that may generate the stressor. Stressor/resource interactions that were determined to have negligible (as defined for the purposes of the NEPA analyses) or impacts that do not rise to the level of take under the MMPA ( i.e., vessel, aircraft, or weapons noise) were not carried forward for analysis in the application. NMFS reviewed the Action Proponents' analysis and conclusions on de minimis sources ( i.e., those that are not likely to result in the take of marine mammals) and finds them complete and supportable (see section 3.7.4 of the technical report “Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and Analytical Approach for Phase IV Training and Testing” (U.S. Department of the Navy, 2024)).

Acoustic Stressors

Acoustic stressors include acoustic signals emitted into the water for a specific purpose, such as sonar, other transducers (devices that convert energy from one form to another—in this case, into sound waves), and air guns, as well as incidental sources of broadband sound produced as a byproduct of vessel movement, aircraft transits, use of weapons or other deployed objects, vibratory pile extraction, and vibratory and impact pile driving. Explosives also produce broadband sound but are characterized separately from other acoustic sources due to their unique hazardous characteristics. Characteristics of each of these sound sources are described in the following sections

d testing requirements, which are linked to real world events.

Sonar and Other Transducers—

Active sonar and other transducers emit non-impulsive sound waves into the water to detect objects, navigate safely, and communicate. Passive sonars differ from active sound sources in that they do not emit acoustic signals; rather, they only receive acoustic information about the environment, or listen. In this proposed rule, the terms sonar and other transducers will be used to indicate active sound sources unless otherwise specified.

The Action Proponents employ a variety of sonars and other transducers to obtain and transmit information about the undersea environment. Some examples are mid-frequency hull-mounted sonars used to find and track enemy submarines; high-frequency small object detection sonars used to detect mines; high-frequency underwater modems used to transfer data over short ranges; and extremely high-frequency (greater than 200 kilohertz (kHz)) Doppler sonars used for navigation, like those used on commercial and private vessels. The characteristics of these sonars and other transducers, such as source level (SL), beam width, directivity, and frequency, depend on the purpose of the source. Higher frequencies can carry more information or provide more information about objects off which they reflect, but attenuate more rapidly. Lower frequencies attenuate less rapidly, so they may detect objects over a longer distance, but with less detail.

Propagation of sound produced underwater is highly dependent on environmental characteristics such as bathymetry, seafloor type, water depth, temperature, and salinity. The sound received at a particular location will be different than near the source due to the interaction of many factors, including propagation loss; how the sound is reflected, refracted, or scattered; the potential for reverberation; and interference due to multi-path propagation. In addition, absorption greatly affects the distance over which higher-frequency sounds propagate

allow for greater resolution and, due to their greater attenuation, are most effective over shorter distances. Mine detection sonar can be deployed (towed or vessel hull-mounted) at variable depths on moving platforms (ships, helicopters, or unmanned vehicles) to sweep a suspected mined area. Hull-mounted anti-submarine sonars can also be used in an object detection mode known as “Kingfisher” mode. Sonars used for imaging are usually used in close proximity to the area of interest, such as pointing downward near the seafloor.

Mine detection sonar use would be concentrated in areas where practice mines are deployed, typically in water depths less than 200 ft (60.9 m), and at established training or testing minefields or temporary minefields close to strategic ports and harbors. Kingfisher mode on vessels is most likely to be used when transiting to and from port. Sound sources used for imaging would be used throughout the AFTT Study Area.

Navigation and Safety

Similar to commercial and private vessels, the Action Proponents' vessels employ navigational acoustic devices, including speed logs, Doppler sonars for ship positioning, and fathometers. These may be in use at any time for safe vessel operation. These sources are typically highly directional to obtain specific navigational data.

Communication

Sound sources used to transmit data (such as underwater modems), provide location (pingers), or send a single brief release signal to seafloor-mounted devices (acoustic release) may be used throughout the AFTT Study Area. These sources typically have low duty cycles and are usually only used when it is necessary to send a detectable acoustic message.

Classification of Sonar and Other Transducers

Sonars and other transducers are grouped into bins based on their acoustic properties. Sonars and other transducers are now grouped into bins based on the frequency or bandwidth, source level, duty-cycle, and three-dimensional beam coverage

ly have low duty cycles and are usually only used when it is necessary to send a detectable acoustic message.

Classification of Sonar and Other Transducers

Sonars and other transducers are grouped into bins based on their acoustic properties. Sonars and other transducers are now grouped into bins based on the frequency or bandwidth, source level, duty-cycle, and three-dimensional beam coverage. Unless stated otherwise, a reference distance of decibel (dB) microPascal (μPa) at 1 m (3.3 ft) is used for sonar and other transducers.

(i) Frequency of the non-impulsive acoustic source:

a. Low-frequency sources operate below 1 kHz;

b. Mid-frequency sources operate at or above 1 kHz, up to and including 10 kHz;

c. High-frequency sources operate above 10 kHz, up to and including 100 kHz; and

d. Very high-frequency sources operate above 100 kHz but below 200 kHz.

(ii) Sound pressure level (SPL):

a. Greater than 160 dB referenced to 1 microPascal (re 1 μPa), but less than 185 dB re 1 μPa;

b. Equal to 185 dB re 1 μPa and up to 205 dB re 1 μPa; and

c. Greater than 205 dB re 1 μPa.

Active sonar and other transducer use that was quantitatively analyzed in the Study Area are shown in table 10.

Table 10—Sonar and Other Transducers Quantitatively Analyzed in the AFTT Study Area Source type Source category Description Unit Navy training annual Navy training 7-year total Coast Guard training annual Coast Guard training 7-year total Navy testing annual Navy testing 7-year total Broadband LF <205 dB H - - - - 206-252 1,580 Broadband LF to MF <205 dB H - - - - 1,501-1,503 10,519 Broadband LF to HF <205 dB C - - - - 791-1,020 5,101 Broadband LF to HF <205 dB H - - - - 2,367-2,571 16,356 Broadband MF to HF <205 dB C 133 931 - - - - Broadband MF to HF <205 dB H 935-951 6,595 280 1,960 2,749-2,950 19,308 Broadband HF to VHF <205 dB H 10 70 - - - - Low-frequency acoustic LFL 160 dB to 185 dB H - - - - 1,969 13,783 Low-frequency acoustic LFM 185 dB to 205 dB C - - - - 360 2,520 Low-frequency acoustic LFM 185 dB to 2

Table 13 shows explosives use that was quantitatively analyzed in the Study Area. A range of annual use indicates that occurrence is anticipated to vary annually, consistent with the variation in the number of annual activities described in chapter 2 (Description of Proposed Action and Alternatives) of the 2024 AFTT Draft Supplemental EIS/OEIS. The 7-year total takes that variability into account.

Table 13—Explosive Sources Quantitatively Analyzed Proposed for Use Underwater or at the Water Surface Bin Net explosive weight Example explosive source Navy training annual Navy training 7-year Coast Guard training annual Coast Guard training 7-year Navy testing annual Navy testing 7-year E1 0.1-0.25 Medium-caliber projectile 3,002 21,014 - - 1,825 12,775 E2 >0.25-0.5 LAW rocket 60 420 - - - - E3 >0.5-2.5 2.75-inch rocket 5,078 35,546 180 1,260 1,069-1,971 8,705 E4 >2.5-5 Mine neutralization charge 82 574 - - 2,893-4,687 30,889 E5 >5-10 Large-caliber projectile 1,109 7,763 - - 1,268-1,860 11,540 E6 >10-20 Hellfire missile 508 3,556 - - 17-25 125 E7 >20-60 Demo block/shaped charge 10 70 - - 8-22 62 E8 >60-100 Maverick missile 20 140 - - 10-13 41 E9 >100-250 500 lb bomb 138 966 - - 5 35 E10 >250-500 Harpoon missile 71 497 - - 4 28 E11 >500-675 Torpedo 1 7 - - 1-2 8 E12 >675-1,000 2,000 lb bomb 20 140 - - - - E16 >7,250-14,500 Small ship shock trial - - - - 0-6 15 Note: > = greater than, lb = pound, - = not applicable. Propagation of explosive pressure waves in water is highly dependent on environmental characteristics such as bathymetry, seafloor type, water depth, temperature, and salinity, which affect how the pressure waves are reflected, refracted, or scattered; the potential for reverberation; and interference due to multi-path propagation. In addition, absorption greatly affects the distance over which higher-frequency components of explosive broadband noise can propagate

occasionally kill cetaceans (Abramson et al., 2011; Berman-Kowalewski et al., 2010; Calambokidis, 2012, Crum et al., 2019, Douglas et al., 2008, Laggner, 2009, Lammers et al., 2003, Van der Hoop et al., 2012, Van der Hoop et al., 2013), although reviews of the literature on vessel strikes mainly involve collisions between commercial vessels and whales (Jensen and Silber, 2003, Laist et al., 2001). Vessel speed, size, and mass are all important factors in determining both the potential likelihood and impacts of a vessel strike to marine mammals (Blondin et al., 2025; Conn and Silber, 2013; Garrison et al., 2025; Gende et al., 2011; Redfern et al., 2019; Silber et al., 2010; Szesciorka et al., 2019; Vanderlaan and Taggart, 2007; Wiley et al., 2016). For large vessels, speed and angle of approach can influence the severity of a strike.

The Action Proponents' vessels transit at speeds that are optimal for fuel conservation or to meet training and testing requirements. From unpublished Navy data, average median speed for large Navy ships in the other Navy ranges from 2011-2015 varied from 10 to 15 kn (18.5 to 27.8 km/hr) depending on ship class and geographic location ( i.e., slower speeds close to the coast). Similar patterns are anticipated in the AFTT Study Area. A full description of the Action Proponents' vessels proposed for use during military readiness activities can be found in chapter 2 (Description of Proposed Action and Alternatives) of the 2024 AFTT Draft Supplemental EIS/OEIS.

While these speeds for large Navy vessels are representative of most events, some of the Action Proponents' vessels may need to temporarily operate outside of these parameters. For example, to produce the required relative wind speed over the flight deck, an aircraft carrier engaged in flight operations must adjust its speed through the water accordingly. There are a few specific events, including high speed tests of newly constructed vessels, where the Action Proponents' vessel would operate at higher speeds

e. Per vessel safety requirements, personnel standing watch also report any marine mammals sighted in the path of the vessel as a standard collision avoidance procedure. All vessels proceed at a safe speed so they can take proper and effective action to avoid a collision with any sighted object or disturbance and can stop within a distance appropriate to the prevailing circumstances and conditions. As described in the Standard Operating Procedures section, the Action Proponents utilize Lookouts to avoid collisions, and Lookouts are trained to spot marine mammals so that vessels may change course or take other appropriate action to avoid collisions. Despite the precautions, should a vessel strike occur, NMFS anticipates that it would likely result in incidental take in the form of serious injury and/or mortality, though it is possible that it could result in non-serious injury (Level A harassment). Accordingly, for the purposes of this analysis, NMFS assumes that any vessel strike would result in serious injury or mortality.

Proposed mitigation, monitoring, and reporting measures are described in detail later in this document (please see Proposed Mitigation Measures section, Proposed Monitoring section, and Proposed Reporting section).

Description of Marine Mammals in the Area of Specified Activities

Marine mammal species and their associated stocks that have the potential to occur in the AFTT Study Area are presented in table 14 along with each stock's Endangered Species Act (ESA) and MMPA statuses, abundance estimate and associated coefficient of variation (CV) value, minimum abundance estimate, potential biological removal (PBR), annual M/SI, and potential occurrence in the AFTT Study Area. The Action Proponents request authorization to take individuals of 41 species (81 stocks) by Level A and Level B harassment incidental to military readiness activities from the use of sonar and other transducers, in-water detonations, air guns, pile driving/extraction, and vessel movement in the AFTT Study Area

(0.46, 68, 2018) 0.7 5.2 Gulf RC N/A N/A. Blainville's Beaked Whale Mesoplodon densirostris Western North Atlantic 14 -, -, N 2,936 (0.26, 2,374, 2021) 24 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, Gulf RC, Other AFTT Areas N/A N/A. Goose-Beaked Whale Ziphius cavirostris Northern Gulf of America -, -, N 18 (0.75, 10, 2018) 0.1 5.2 Gulf RC N/A N/A. Goose-Beaked Whale Ziphius cavirostris Puerto Rico and U.S. Virgin Islands -, -, Y UNK (UNK, UNK, N/A) UNK UNK Other AFTT Areas N/A N/A. Goose-Beaked Whale Ziphius cavirostris Western North Atlantic -, -, N 4,260 (0.24, 3,817, 2021) 38 0.2 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Other AFTT Areas N/A N/A. Gervais' Beaked Whale Mesoplodon europaeus Northern Gulf of America -, -, N 20 (0.98, 10, 2018) 0.1 5.2 Gulf RC N/A N/A. Gervais' Beaked Whale Mesoplodon europaeus Western North Atlantic 15 -, -, N 8,595 (0.24, 7,022, 2021) 70 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, Gulf RC, Other AFTT Areas N/A N/A. Northern Bottlenose Whale Hyperoodon ampullatus Western North Atlantic -, -, N UNK (UNK, UNK, 2016) UNK 0 Other AFTT Areas N/A N/A. Sowerby's Beaked Whale Mesoplodon bidens Western North Atlantic -, -, N 492 (0.50, 340, 2021) 3.4 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, Gulf RC, Other AFTT Areas N/A N/A. True's Beaked Whale Mesoplodon mirus Western North Atlantic -, -, N 4,480 (0.34, 3,391, 2021) 34 0.2 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, Gulf RC, Other AFTT Areas N/A N/A. Family Delphinidae: Atlantic Spotted Dolphin Stenella frontalis Northern Gulf of America -, -, N 21,506 (0.26, 17,339, 2018) 166 36 Gulf RC, Other AFTT Areas N/A N/A. Atlantic Spotted Dolphin Stenella frontalis Puerto Rico and U.S. Virgin Islands -, -, Y UNK (UNK, UNK, N/A) UNK UNK Other AFTT Areas N/A N/A

Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, Gulf RC, Other AFTT Areas N/A N/A. Family Delphinidae: Atlantic Spotted Dolphin Stenella frontalis Northern Gulf of America -, -, N 21,506 (0.26, 17,339, 2018) 166 36 Gulf RC, Other AFTT Areas N/A N/A. Atlantic Spotted Dolphin Stenella frontalis Puerto Rico and U.S. Virgin Islands -, -, Y UNK (UNK, UNK, N/A) UNK UNK Other AFTT Areas N/A N/A. Atlantic Spotted Dolphin Stenella frontalis Western North Atlantic -, -, N 31,506 (0.28, 25,042, 2021) 250 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A. Atlantic White-Sided Dolphin Lagenorhynchus acutus Western North Atlantic -, -, N 93,233 (0.71, 54,443, 2021) 544 28 Northeast RC, VACAPES RC, Other AFTT Areas N/A Civilian Ports: Boston, MA; Coast Guard Stations: Boston, MA. Bottlenose Dolphin Tursiops truncatus Biscayne Bay -, -, N 241 (0.04, 233, 2019) 2.3 1 Other AFTT Areas N/A N/A. Tamanend's bottlenose dolphin Tursiops erebennus Western North Atlantic, Central Florida Coastal -, -, Y 2,541 (0.46, 1,760, 2021) 18 0.2 JAX RC JAX RC Inshore Civilian Ports: Port Canaveral, FL. Bottlenose Dolphin Tursiops truncatus Central GA Estuarine -, -, N UNK (UNK, UNK, 2008-2009) UND 0.4 Other AFTT Areas N/A N/A. Bottlenose Dolphin Tursiops truncatus Charleston Estuarine -, -, Y UNK (UNK, UNK, 2005-2006) UND 2.2 Other AFTT Areas JAX RC Inshore N/A. Bottlenose Dolphin Tursiops truncatus Gulf of America Bay, Sound, and Estuaries 16 Y Gulf RC Gulf RC Inshore N/A. Bottlenose Dolphin Tursiops truncatus Gulf of America Eastern Coastal -, -, N 16,407 (0.17, 14,199, 2018) 114 9.2 Gulf RC Gulf RC Inshore N/A. Bottlenose Dolphin Tursiops truncatus Gulf of America Northern Coastal -, -, N 11,543 (0.19, 9,881, 2018) 89 28 Gulf RC Gulf RC Inshore N/A. Bottlenose Dolphin Tursiops truncatus Northern Gulf of America Oceanic -, -, N 7,462 (0.31, 5,769, 2018) 58 32 Gulf RC N/A N/A

Dolphin Tursiops truncatus Gulf of America Eastern Coastal -, -, N 16,407 (0.17, 14,199, 2018) 114 9.2 Gulf RC Gulf RC Inshore N/A. Bottlenose Dolphin Tursiops truncatus Gulf of America Northern Coastal -, -, N 11,543 (0.19, 9,881, 2018) 89 28 Gulf RC Gulf RC Inshore N/A. Bottlenose Dolphin Tursiops truncatus Northern Gulf of America Oceanic -, -, N 7,462 (0.31, 5,769, 2018) 58 32 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Gulf of America Western Coastal -, -, N 20,759 (0.13, 18,585, 2018) 167 36 Gulf RC Gulf RC Inshore Civilian Ports: Beaumont, TX, Corpus Christi, TX, Pascagoula, MS; Coast Guard Stations: Corpus Christi, TX. Bottlenose Dolphin Tursiops truncatus Florida Bay -, -, N UNK (UNK, UNK, 2003) UNK 0.2 Other AFTT Areas N/A N/A. Bottlenose Dolphin Tursiops truncatus Indian River Lagoon Estuarine -, -, Y 1,032 (0.03, 1,004, 2016-2017) 10 5.7 Other AFTT Areas JAX RC Inshore Civilian Ports: Port Canaveral, FL. Bottlenose Dolphin Tursiops truncatus Jacksonville Estuarine -, -, Y UNK (UNK, UNK, n/a) UNK 2 JAX RC JAX RC Inshore Civilian Ports: Port Canaveral, FL. Bottlenose Dolphin Tursiops truncatus MS Sound, Lake Borgne, Bay Boudreau -, -, Y 1,265 (0.35, 947, 2018) 8.5 59 Gulf RC Gulf Inshore N/A. Tamanend's bottlenose Dolphin Tursiops erebennus Western North Atlantic, Northern Florida Coastal -, -, Y 3,619 (0.35, 2,711, 2021) 27 0.2 Other AFTT Areas JAX RC Inshore Civilian Ports: Kings Bay, GA, Savannah, GA. Bottlenose Dolphin Tursiops truncatus Northern GA/Southern SC Estuarine -, -, Y UNK (UNK, UNK, See SAR) UNK 1.5 Other AFTT Areas JAX RC Inshore N/A. Bottlenose Dolphin Tursiops truncatus Northern Gulf of America Continental Shelf -, -, N 63,280 (0.11, 57,917, 2018) 556 65 Gulf RC N/A N/A

Y 3,619 (0.35, 2,711, 2021) 27 0.2 Other AFTT Areas JAX RC Inshore Civilian Ports: Kings Bay, GA, Savannah, GA. Bottlenose Dolphin Tursiops truncatus Northern GA/Southern SC Estuarine -, -, Y UNK (UNK, UNK, See SAR) UNK 1.5 Other AFTT Areas JAX RC Inshore N/A. Bottlenose Dolphin Tursiops truncatus Northern Gulf of America Continental Shelf -, -, N 63,280 (0.11, 57,917, 2018) 556 65 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Western North Atlantic, Northern Migratory Coastal -, -, Y 6,639 (0.41, 4,759, 2016) 48 12.2-21.5 VACAPES RC, Navy Cherry Point RC, JAX RC, Key West RC, Other AFTT Areas VACAPES RC Inshore Civilian Ports: Earle, NJ, Delaware Bay, DE, Hampton Roads, VA, Morehead City, NC; Coast Guard Stations: Virginia Beach, VA. Bottlenose Dolphin Tursiops truncatus Northern NC Estuarine -, -, Y 823 (0.06, 782, 2017) 7.8 7.2-30 Other AFTT Areas N/A Civilian Ports: Morehead City, NC, Wilmington, NC. Bottlenose Dolphin Tursiops truncatus Northern SC Estuarine -, -, N 453 (0.28, 359, 2016) 3.6 0.5 Other AFTT Areas JAX RC Inshore N/A. Bottlenose Dolphin Tursiops truncatus Nueces Bay, Corpus Christi -, -, Y 58 (0.61, UNK, 1992) UND 0.2 Gulf RC N/A Civilian Ports: Corpus Christi, TX. Bottlenose Dolphin Tursiops truncatus Sabine Lake -, -, N 122 (0.19, 104, 2017) 0.9 0 Gulf RC N/A Civilian Ports: Beaumont, TX. Tamanend's bottlenose Dolphin Tursiops erebennus Western North Atlantic South Carolina/Georgia Coastal -, -, Y 9,121 (0.28, 7,261, 2021) 73 0.2-0.6 Other AFTT Areas JAX RC Inshore Civilian Ports: Kings Bay, GA, Savannah, GA. Bottlenose Dolphin Tursiops truncatus Southern GA Estuarine System -, -, N UNK (UNK, UNK, 2008-2009) UND 0.1 Other AFTT Areas JAX RC Inshore Civilian Ports: Kings Bay, GA, Savannah, GA

N/A, 1992) UND 0.2 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Caloosahatchee River -, -, Y 0 (N/A, N/A, 1985) UND 0.4 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Choctawhatchee Bay -, -, Y 179 (0.04, UNK, 2007) UND 0.4 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Chokoloskee Bay, Ten Thousand Islands, Gullivan Bay -, -, Y UNK (N/A, UNK, N/A) UND 0.2 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Copano Bay, Aransas Bay, San Antonio Bay, Redfish Bay, Espiritu Santo Bay -, -, Y 55 (0.82, UNK, 1992) UND 0.6 Gulf RC N/A Civilian Ports: Corpus Christi, TX. Bottlenose Dolphin Tursiops truncatus Estero Bay -, -, Y UNK (N/A, UNK, N/A) UND 0.4 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Florida Keys -, -, Y UNK (N/A, UNK, N/A) UND 0.2 Gulf RC Key West Range Complex Inshore N/A. Bottlenose Dolphin Tursiops truncatus Galveston Bay, East Bay, Trinity Bay -, -, N 842 (0.08, 787, 2016) 6.3 1 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Laguna Madre -, -, Y 80 (1.57, UNK, 1992) UND 0.8 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Matagorda Bay, Tres Palacios Bay, Lavaca Bay -, -, Y 61 (0.45, UNK, 1992) UND 0.4 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Mobile and Bonsecour Bays -, -, Y 122 (0.34, UNK, 1993) UND 16 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus MS River Delta -, -, N 1,446 (0.19, 1,238, 2018) 11 9.2 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Pensacola and East Bays -, -, Y 33 (0.8, UNK, 1993) UND 0.4 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Perdido Bay -, -, Y 0 (N/A, N/A, 1993) UND 0.8 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Pine Island Sound, Charlotte Harbor, Gasparilla Sound, Lemon Bay -, -, Y 826 (0.09, UNK, 2006) UND 1 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Sarasota Bays -, -, N 158 (0.27, 126, 2015) 1 0.2 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus St. Andrew Bay -, -, N 199 (0.09, 185, 2016) 1.5 0.2 Gulf RC Gulf Inshore N/A

ND 0.8 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Pine Island Sound, Charlotte Harbor, Gasparilla Sound, Lemon Bay -, -, Y 826 (0.09, UNK, 2006) UND 1 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Sarasota Bays -, -, N 158 (0.27, 126, 2015) 1 0.2 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus St. Andrew Bay -, -, N 199 (0.09, 185, 2016) 1.5 0.2 Gulf RC Gulf Inshore N/A. Bottlenose Dolphin Tursiops truncatus St. Joseph Bay -, -, N 142 (0.17, 123, 2011) 1 UNK Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus St. Joseph Sound, Clearwater Harbor -, -, Y UNK (N/A, UNK, N/A) UND 0.8 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus St. Vincent Sound, Apalachicola Bay, St. George Sound -, -, Y 439 (0.14, UNK, 2007) UND 0.2 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Tampa Bay -, -, Y UNK (N/A, UNK, N/A) UND 3 Gulf RC N/A Civilian Ports: Tampa, FL. Bottlenose Dolphin Tursiops truncatus Terrebonne and Timbalier Bays Estuarine System -, -, N 3,870 (0.15, 3,426, 2016) 27 0.2 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Vermillion Bay, West Cote Blanche Bay, Atchafalaya Bay -, -, Y 0 (N/A, N/A, 1992) UND 0 Gulf RC Gulf Inshore N/A. Bottlenose Dolphin Tursiops truncatus Waccasassa Bay, Withlacoochee Bay, Crystal Bay -, -, Y UNK (N/A, UNK, N/A) UND 0.4 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus West Bay -, -, N 37 (0.05, 35, 2015) 0.3 0 Gulf RC N/A N/A. Bottlenose Dolphin Tursiops truncatus Whitewater Bay -, -, Y UNK (N/A, UNK, N/A) UND 0 Gulf RC N/A N/A. Clymene Dolphin Stenella clymene Northern Gulf of America -, -, Y 513 (1.03, 250, 2018) 2.5 8.4 Gulf RC, Other AFTT Areas N/A N/A. Clymene Dolphin Stenella clymene Western North Atlantic -, -, N 21,778 (0.72, 12,622, 2021) 126 0 Northeast RC, NUWC Division, Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A

tenella clymene Northern Gulf of America -, -, Y 513 (1.03, 250, 2018) 2.5 8.4 Gulf RC, Other AFTT Areas N/A N/A. Clymene Dolphin Stenella clymene Western North Atlantic -, -, N 21,778 (0.72, 12,622, 2021) 126 0 Northeast RC, NUWC Division, Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A. Common Dolphin Delphinus delphis Western North Atlantic -, -, N 93,100 (0.56, 59,897, 2021) 1,452 414 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A. False Killer Whale Pseudorca crassidens Northern Gulf of America -, -, N 494 (0.79, 276, 2018) 2.8 2.2 Gulf RC, Other AFTT Areas N/A N/A. False Killer Whale Pseudorca crassidens Western North Atlantic -, -, N 1,298 (0.72, 775, 2021) 7.6 0 NUWC Division, Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A. Fraser's Dolphin Lagenodelphis hosei Northern Gulf of America -, -, N 213 (1.03, 104, 2018) 1 UNK Gulf RC N/A N/A. Fraser's Dolphin Lagenodelphis hosei Western North Atlantic -, -, N UNK (UNK, UNK, 2021) UNK 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A. Killer Whale Orcinus orca Northern Gulf of America -, -, N 267 (0.75, 152, 2018) 1.5 UNK Gulf RC N/A N/A. Killer Whale Orcinus orca Western North Atlantic -, -, N UNK (UNK, UNK, 2016) UNK 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A

er AFTT Areas N/A N/A. Killer Whale Orcinus orca Northern Gulf of America -, -, N 267 (0.75, 152, 2018) 1.5 UNK Gulf RC N/A N/A. Killer Whale Orcinus orca Western North Atlantic -, -, N UNK (UNK, UNK, 2016) UNK 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A. Long-Finned Pilot Whale Globicephala melas Western North Atlantic -, -, N 39,215 (0.30, 30,627, 2021) 306 5.7 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A. Melon-Headed Whale Peponocephala electra Northern Gulf of America -, -, N 1,749 (0.68, 1,039, 2018) 10 9.5 Gulf RC N/A N/A. Melon-Headed Whale Peponocephala electra Western North Atlantic -, -, N UNK (UNK, UNK, 2021) UNK 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A. Pantropical Spotted Dolphin Stenella attenuata Northern Gulf of America -, -, N 37,195 (0.24, 30,377, 2018) 304 241 Gulf RC N/A N/A. Pantropical Spotted Dolphin Stenella attenuata Western North Atlantic -, D, N 2,757 (0.50, 1,856, 2021) 19 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A. Pygmy Killer Whale Feresa attenuata Northern Gulf of America -, -, N 613 (1.15, 283, 2018) 2.8 1.6 Gulf RC N/A N/A. Pygmy Killer Whale Feresa attenuata Western North Atlantic -, -, N UNK (UNK, UNK, 2021) UNK 0 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC, JAX RC, SFOMF, Key West RC, NSWC Panama City Division Testing Range, Gulf RC, Other AFTT Areas N/A N/A

Seal Pagophilus groenlandicus Western North Atlantic -, -, N 7.6M (UNK, 7.1M, 2019) 426,000 178,573 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC N/A N/A. Hooded Seal Cystophora cristata Western North Atlantic -, -, N UNK (UNK, UNK, n/a) UNK 1,680 Northeast RC, NUWC Division Newport Testing Range, VACAPES RC, Navy Cherry Point RC N/A Civilian Ports: Boston, MA. Note: %: percent; AFTT: Atlantic Fleet Training and Testing; CV: coefficient of variation; EEZ: Exclusive Economic Zone; EIS: Environmental Impact Statement; ESA: Endangered Species Act; JAX: Jacksonville; Min.: minimum; MMPA: Marine Mammal Protection Act; NMFS: National Marine Fisheries Service; NSWC: Naval Surface Warfare Center; NUWC: Naval Undersea Warfare Center; RC: Range Complex; SAR: Stock Assessment Report; SFOMF: Naval Surface Warfare Center, Carderock Division, South Florida Ocean Measurement Facility Testing Range; U.S.: United States; USFWS: U.S. Fish and Wildlife Service; VACAPES: Virginia Capes. Marine mammals in the Gulf of America are named in the most recent SARs (Hayes et al., 2024) with reference to the formerly named “Gulf of Mexico.” This Notice refers to these marine mammal stocks as Northern Gulf of America stocks. The geographical location of the stocks remains the same. 1 Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy ( https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/ ). 2 Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future

ies Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is automatically designated under the MMPA as depleted and as a strategic stock. 3 NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. CV is coefficient of variation; N min is the minimum estimate of stock abundance. 4 These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined ( e.g., commercial fisheries, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated with estimated mortality due to commercial fisheries is presented in some cases. 5 NMFS uses “credible interval” to characterize the uncertainty as opposed to CV for North Atlantic right whales (Hayes et al., 2024). 6 Photo-ID catalog count of 402 recognizable blue whale individuals from the Gulf of St. Lawrence is considered a minimum population estimate for the western North Atlantic stock (Waring et al., 2010). An additional 39 (0.64) were documented in the summer of 2016 for Central Virginia to Bay of Fundy (Waring et al., 2010). 7 The West Greenland stock of fin whales is not managed by NMFS and, therefore, does not have an associated Stock Assessment Report. Abundance and a 95% confidence interval were presented in Heide-Jorgensen et al. (2010a). 8 The Gulf of St. Lawrence stock of fin whales is not managed by NMFS and, therefore, does not have an associated Stock Assessment Report

at this time. 17 Estimate may include sightings of the coastal form. 18 Harbor porpoises in the Gulf of St. Lawrence are not managed by NMFS and have no associated Stock Assessment Report. 19 Harbor porpoises in Newfoundland are not managed by NMFS and have no associated Stock Assessment Report. 20 Harbor porpoises in Greenland are not managed by NMFS and have no associated Stock Assessment Report. Species Not Included in the Analysis

The species carried forward for analysis (and described in table 14) are those likely to be found in the AFTT Study Area based on the most recent data available and do not include species that may have once inhabited or transited the area but have not been sighted in recent years ( e.g., species which were extirpated from factors such as 19th and 20th century commercial exploitation). Several species that may be present in the northwestern Atlantic Ocean have an extremely low probability of presence in the AFTT Study Area. These species are considered extralimital (not anticipated to occur in the Study Area) or rare (occur in the Study Area sporadically, but sightings are rare). These extralimital species include the bowhead whale ( Balaena mysticetus ), beluga whale ( Delphinapterus leucas ), narwhal ( Monodon monoceros ), ringed seal ( Pusa hispida ), and bearded seal ( Erignathus barbatus ). Bowhead whales are likely to be found only in the Labrador Current open ocean area but, in 2012 and 2014, the same bowhead whale was observed in Cape Cod Bay, which represents the southernmost record of this species in the western North Atlantic. In June 2014, a beluga whale was observed in several bays and inlets of Rhode Island and Massachusetts (Swaintek, 2014). This sighting likely represents an extralimital beluga whale occurrence in the Northeast United States Continental Shelf Large Marine Ecosystem. Narwhals prefer cold Arctic waters, and there is no stock of narwhal that occurs in the U.S

ered further in this document.

Below, we consider additional information about the marine mammals in the area of the specified activities that informs our analysis, such as identifying known areas of important habitat or behaviors, or where Unusual Mortality Events (UME) have been designated.

Critical Habitat

Currently, only the NARW has ESA-designated critical habitat in the AFTT Study Area. However, NMFS has recently published a proposed rule proposing new ESA-designated critical habitat for the Rice's whale (88 FR 47453, July 24, 2023).

North Atlantic Right Whale

On February 26, 2016, NMFS issued a final rule (81 FR 4838) to replace the critical habitat for NARW with two new areas. The areas now designated as critical habitat contain approximately 29,763 nmi 2 (102,084 km 2 ) of marine habitat in the Gulf of Maine and Georges Bank region (Unit 1), essential for NARW foraging and off the Southeast U.S. coast (Unit 2), including the coast of North Carolina, South Carolina, Georgia, and Florida, which are key areas essential for calving. These two ESA-designated critical habitats were established to replace three smaller previously ESA-designated critical habitats (Cape Cod Bay/Massachusetts Bay/Stellwagen Bank, Great South Channel, and the coastal waters of Georgia and Florida in the southeastern United States) that had been designated by NMFS in 1994 (59 FR 28805, June 3, 1994). Two additional areas in Canadian waters, Grand Manan Basin and Roseway Basin, were identified and designated as critical habitat under Canada's endangered species law (section 58 (5) of the Species at Risk Act (SARA), S. C. 2002, c. 29) and identified in Final Recovery Strategy for the NARW, posted June 2009 on the SARA Public Registry

d been designated by NMFS in 1994 (59 FR 28805, June 3, 1994). Two additional areas in Canadian waters, Grand Manan Basin and Roseway Basin, were identified and designated as critical habitat under Canada's endangered species law (section 58 (5) of the Species at Risk Act (SARA), S. C. 2002, c. 29) and identified in Final Recovery Strategy for the NARW, posted June 2009 on the SARA Public Registry.

Unit 1 encompasses the Gulf of Maine and Georges Bank region including the large embayments of Cape Cod Bay and Massachusetts Bay and deep underwater basins, as well as state waters, except for inshore areas, bays, harbors, and inlets, from Maine through Massachusetts in addition to Federal waters, all of which are key areas (see figure 4.1-1 of the application). It also does not include waters landward of the 72 COLREGS lines (33 CFR part 80). The essential physical and biological features of foraging habitat for NARW are: (1) The physical oceanographic conditions and structures of the Gulf of Maine and Georges Bank region that combine to distribute and aggregate Calanus finmarchicus for right whale foraging, namely prevailing currents and circulation patterns, bathymetric features (basins, banks, and channels), oceanic fronts, density gradients, and temperature regimes; (2) low flow velocities in Jordan, Wilkinson, and Georges Basins that allow diapausing C. finmarchicus to aggregate passively below the convective layer so that the copepods are retained in the basins; (3) late stage C. finmarchicus in dense aggregations in the Gulf of Maine and Georges Bank region; and (4) diapausing C. finmarchicus in aggregations in the Gulf of Maine and Georges Bank region.

Unit 2 consists of all marine waters from Cape Fear, North Carolina, southward to approximately 27 nmi below Cape Canaveral, Florida, within the area bounded on the west by the shoreline and the 72 COLREGS lines, and on the east by rhumb lines connecting the specific points described below (see figure 4.1-2 of the application)

rchicus in aggregations in the Gulf of Maine and Georges Bank region.

Unit 2 consists of all marine waters from Cape Fear, North Carolina, southward to approximately 27 nmi below Cape Canaveral, Florida, within the area bounded on the west by the shoreline and the 72 COLREGS lines, and on the east by rhumb lines connecting the specific points described below (see figure 4.1-2 of the application). The essential physical and biological features correlated with the distribution of NARW in the southern critical habitat area provide an optimum environment for calving. These are: (1) Calm sea surface conditions of Force 4 or less on the Beaufort Wind Scale; (2) sea surface temperatures from a minimum of 44.6 °F (7 °C), and never more than 62.6 °F (17 °C); and (3) water depths of 19.7 to 91.9 ft (6 to 28 m), where these features simultaneously co-occur over contiguous areas of at least 231 nmi 2 (792.3 km 2 ) of ocean waters during the months of November through April. For example, the bathymetry of the inner and nearshore middle shelf area minimizes the effect of strong winds and offshore waves, limiting the formation of large waves and rough water. The average temperature of critical habitat waters is cooler during the time right whales are present due to a lack of influence by the Gulf Stream and cool freshwater runoff from coastal areas. The water temperatures may provide an optimal balance between offshore waters that are too warm for nursing mothers to tolerate, yet not too cool for calves that may only have minimal fatty insulation. Reproductive females and calves are expected to be concentrated in the critical habitat from December through April.

Rice's Whale

On August 23, 2021, NMFS published a final rule that revised the listing of Rice's whales under the ESA to reflect the change in the scientifically accepted taxonomy and nomenclature of this species (86 FR 47022)

r calves that may only have minimal fatty insulation. Reproductive females and calves are expected to be concentrated in the critical habitat from December through April.

Rice's Whale

On August 23, 2021, NMFS published a final rule that revised the listing of Rice's whales under the ESA to reflect the change in the scientifically accepted taxonomy and nomenclature of this species (86 FR 47022). Prior to this revision, the Rice's whale was listed in 2019 under the ESA as an endangered subspecies of the Bryde's whale (Gulf of America subspecies (referred to as the Gulf of Mexico subspecies in 86 FR 47022)). The 2019 listing rule indicated that, with a total abundance of approximately 100 individuals, small population size and restricted range are the most serious threats to this species (84 FR 15446, April 15, 2019). However, other threats such as energy exploration, development, and production; oil spills and oil spill responses; vessel collision; fishing gear entanglement; and anthropogenic noise were also identified as threats that contribute to the risk of extinction.

The specific occupied areas proposed for designation as critical habitat for the Rice's whale contain approximately 28,270.65 mi 2 (73,220.65 km 2 ) of continental shelf and slope associated waters between 100 m and 400 m (328 ft and 1,312 ft) isobaths within the Gulf of America spanning from the U.S. EEZ boundary off the southwestern coast of Texas, to the boundary between the South Atlantic Fishery Management Council and the Gulf Fishery Management Council off the southeastern coast of Florida.

In the final listing rule, NMFS stated that critical habitat was not determinable at the time of the listing, because sufficient information was not currently available on the geographical area occupied by the species (84 FR 15446, April 15, 2019)

, to the boundary between the South Atlantic Fishery Management Council and the Gulf Fishery Management Council off the southeastern coast of Florida.

In the final listing rule, NMFS stated that critical habitat was not determinable at the time of the listing, because sufficient information was not currently available on the geographical area occupied by the species (84 FR 15446, April 15, 2019). On July 24, 2023, NMFS published a proposed rule describing the proposed critical habitat designation, including supporting information on Rice's whale biology, distribution, and habitat use, and the methods used to develop the proposed designation (88 FR 47453). The physical and biological features essential to the conservation of the species identified in the proposed rule are:

(i) Sufficient density, quality, abundance, and accessibility of small demersal and vertically migrating prey species, including scombriformes, stomiiformes, myctophiformes, and myopsida;

(ii) Marine water with:

A. Elevated productivity,

B. Bottom temperatures of 50-66.2 °F (10-19 °C), and

C. Levels of pollutants that do not preclude or inhibit any demographic function; and

(iii) Sufficiently quiet conditions for normal use and occupancy, including intraspecific communication, navigation, and detection of prey, predators, and other threats.

Biologically Important Areas

LaBrecque et al. (2015) identified Biologically Important Areas (BIAs) within U.S. waters of the East Coast and Gulf of America, which represent areas and times in which cetaceans are known to concentrate in areas of known importance for activities related to reproduction, feeding, and migration, or areas where small and resident populations are known to occur. Unlike ESA critical habitat, these areas are not formally designated pursuant to any statute or law, but are a compilation of the best available science intended to inform impact and mitigation analyses

ich cetaceans are known to concentrate in areas of known importance for activities related to reproduction, feeding, and migration, or areas where small and resident populations are known to occur. Unlike ESA critical habitat, these areas are not formally designated pursuant to any statute or law, but are a compilation of the best available science intended to inform impact and mitigation analyses. An interactive map of the BIAs is available here: https://oceannoise.noaa.gov/biologically-important-areas. In some cases, additional, or newer, information regarding known feeding, breeding, or migratory areas may be available, and is included below.

On the East Coast, 19 of the 24 identified BIAs fall within or overlap with the AFTT Study Area: 10 feeding (2 for minke whale, 1 for sei whale, 3 for fin whale, 3 for NARW, and 1 for humpback), 1 migration (NARW), 2 reproduction (NARW), and 6 small and resident population (1 for harbor porpoise and 5 for bottlenose dolphin). Figures 4.1-1 through 4.1-14 of the application illustrate how these BIAs overlap with OPAREAs on the East Coast. In the Gulf of America, 4 of the 12 identified BIAs for small and resident populations overlap the AFTT Study Area (1 for Rice's (Bryde's) whale and 3 for bottlenose dolphin). Figures 4.1-9 through 4.1-13 of the application illustrates how these BIAs overlap with OPAREAs in the Gulf of America.

Large Whales Feeding BIAs—East Coast

Two minke whale feeding BIAs are located in the northeast Atlantic from March through November in waters less than 200 m (656 ft) in the southern and southwestern section of the Gulf of Maine including Georges Bank, the Great South Channel, Cape Cod Bay and Massachusetts Bay, Stellwagen Bank, Cape Anne, and Jeffreys Ledge (LaBrecque et al., 2015a; LaBrecque et al., 2015b). LaBrecque et al

f bays, sounds, and estuaries (BSE) in the Gulf of America (see figures 4.1-12 and 4.1-13 in the application). Of the 11 BIAs identified for the BSE bottlenose dolphins in the Gulf of America, three overlap with the Gulf Range Complex (Aransas Pass Area, Texas; Mississippi Sound Area, Mississippi; and St. Joseph Bay Area, Florida), while eight are located adjacent to the AFTT Study Area boundaries.

Rice's (Previously Bryde's) Whale BIA—Gulf of America

The Rice's (previously Bryde's) whale is a very small population that is genetically distinct from Bryde's whales and not genetically diverse within the Gulf of America (Rosel and Wilcox, 2014; Rosel et al., 2021). Further, the species is typically observed only within a narrowly circumscribed area within the eastern Gulf of America. Therefore, this area is described as a year-round BIA by LaBrecque et al. (2015). Previous survey effort covered all oceanic waters of the U.S. Gulf of America, and whales were observed only between approximately the 100- and 300-m (328- and 984-ft) isobaths in the eastern Gulf of America from the head of the De Soto Canyon (south of Pensacola, Florida) to northwest of Tampa Bay, Florida (Maze-Foley and Mullin, 2006; Waring et al., 2016; Rosel and Wilcox, 2014; Rosel et al., 2016). Rosel et al. (2016) expanded this description by stating that, due to the depth of some sightings, the area is more appropriately defined to the 400-m (1,312-ft) isobath and westward to Mobile Bay, Alabama, in order to provide some buffer around the deeper sightings and to include all sightings in the northeastern Gulf of America. Since then, passive acoustic detections of Rice's whale have occurred in the north central and western Gulf of America (Soldevilla et al., 2022; Soldevilla et al., 2024), although the highest densities of Rice's whales have been confined to the northeastern Gulf of America core habitat. The number of individuals that occur in the central and western Gulf of America and nature of their use of this area is poorly understood

ualities. Sanctuary regulations prohibit destroying, causing the loss of, or injuring any sanctuary resource managed under the law or regulations for that sanctuary (15 CFR part 922). NMS are managed on a site-specific basis, and each sanctuary has site-specific regulations. Most, but not all sanctuaries have site-specific regulatory exemptions from the prohibitions for certain military activities. Separately, section 304(d) of the NMSA requires Federal agencies to consult with the Office of National Marine Sanctuaries whenever their Proposed Activities are likely to destroy, cause the loss of, or injure a sanctuary resource. There are five designated NMSs and one proposed NMS within the AFTT Study Area (see section 6.1.3 of the 2024 AFTT Draft Supplemental EIS/OEIS). Two of these sanctuaries, Flower Garden Banks NMS in the Gulf of America and Monitor NMS off of North Carolina, do not inform our assessment of impacts to marine mammals and their habitat.

Three NMSs and one proposed NMS within the AFTT Study Area are

associated with features that inform our assessment of impacts to marine mammals and their habitat: Gerry E. Studds Stellwagen Bank NMS, Gray's Reef NMS, Florida Keys NMS, and Hudson Canyon Proposed NMS. Stellwagen Bank NMS sits at the mouth of Massachusetts Bay, 3 miles (mi; 4.8 km) south of Cape Ann, 3 mi (4.8 km) north of Cape Cod and 25 mi (40.2 km) due east of Boston and provides feeding and nursery grounds for marine mammals including NARW, humpback, sei, and fin whales. The Stellwagen Bank NMS is within critical habitat for the NARW for foraging (Unit 1). Gray's Reef NMS is 19 mi (30.6 km) east of Sapelo Island Georgia, in the South Atlantic Bight (the offshore area between Cape Hatteras, North Carolina and Cape Canaveral, Florida) and is within the designated critical habitat for NARW calving in the southeast (Unit 2)

(112,000 km 2 ) of ocean. Currents, winds, and tides carried these surface oil slicks to shore, fouling more than 1,304.9 mi (2,100 km) of shoreline, including beaches, bays, estuaries, and marshes from eastern Texas to the Florida Panhandle. In addition, some lighter oil compounds evaporated from the slicks, exposing air-breathing organisms like marine mammals to noxious fumes at the sea surface.

DWH oil was found to cause problems with the regulation of stress hormone secretion from adrenal cells and kidney cells, which will affect an animal's ability to regulate body functions and respond appropriately to stressful situations, thus leading to reduced fitness. Bottlenose dolphins living in habitats contaminated with DWH oil showed signs of adrenal dysfunction, and dead, stranded dolphins from areas contaminated with DWH oil had smaller adrenal glands (Schwacke et al., 2014a; Venn-Watson et al., 2015b). Other factors were ruled out as a primary cause for the high prevalence of adverse health effects, reproductive failures, and disease in stranded animals. When all of the data were considered together, the DWH oil spill was determined to be the only reasonable cause for the full suite of observed adverse health effects.

Due to the difficulty of investigating marine mammals in pelagic environments and across the entire region impacted by the event, the injury assessment focused on health assessments conducted on bottlenose dolphins in nearshore habitats and used these populations as case studies for extrapolating to coastal and oceanic populations that received similar or worse exposure to DWH oil, with appropriate adjustments made for differences in behavior, anatomy, physiology, life histories, and population dynamics among species

event, the injury assessment focused on health assessments conducted on bottlenose dolphins in nearshore habitats and used these populations as case studies for extrapolating to coastal and oceanic populations that received similar or worse exposure to DWH oil, with appropriate adjustments made for differences in behavior, anatomy, physiology, life histories, and population dynamics among species. Investigators then used a population modeling approach to capture the overlapping and synergistic relationships among the metrics for injury, and to quantify the entire scope of DWH marine mammal injury to populations into the future, expressed as “lost cetacean years” due to the DWH oil spill (which represents years lost due to premature mortality as well as the resultant loss of reproductive output). This approach allowed for consideration of long-term impacts resulting from immediate losses and reproductive failures in the few years following the spill, as well as expected persistent impacts on survival and reproduction for exposed animals well into the future (Takeshita et al., 2017; Smith et al., 2022). For a more detailed overview of the injury quantification for these stocks and their post-DWH population trajectory, please see Schwacke et al. (2017) and Marques et al. (2023), and for full details of the overall injury quantification, see DWH Marine Mammal Injury Quantification Team (MMIQT) (2015).

The results of the quantification exercise for each affected shelf and oceanic stock, and for northern and western coastal stocks of bottlenose dolphin, are presented in table 15

face near the wellhead. No analysis was performed for Fraser's dolphins or killer whales; although they are present in the Gulf of America, sightings are rare and there were no historical sightings in the oil spill footprint during the surveys used in the quantification process. These stocks were likely injured, but no information was available on which to base a quantification effort at that time.

Table 15—Summary of Modeled Effects of the Deepwater Horizon Oil Spill [DWH NRDA Trustees, 2016] Common name Stock Percent of population exposed to oil (95 percent CI) Percent of population killed (95 percent CI) Percent of females with reproductive failure (95 percent CI) Percent of population with adverse health effects (95 percent CI) Percent of maximum population reduction (95 percent CI) Years to recovery (95 percent CI) * Rice's whale (formerly Bryde's whale) Northern Gulf of America 48 (23-100) 17 (7-24) 22 (10-31) 18 (7-28) −22 69 Sperm whale Northern Gulf of America 16 (11-23) 6 (2-8) 7 (3-10) 6 (2-9) −7 21 Kogia spp Multiple 15 (8-29) 5 (2-7) 7 (3-10) 6 (2-9) −6 11 Beaked whales Multiple 12 (7-22) 4 (2-6) 5 (3-8) 4 (2-7) −6 10 Bottlenose dolphin Northern Gulf of America, Oceanic 10 (5-10) 3 (1-5) 5 (2-6) 4 (1-6) −4 N/A Bottlenose dolphin Gulf of America, Northern Coastal 82 (55-100) 38 (26-58) 37 (17-53) 30 (11-47) −50 (32-73) 39 (23-76) Bottlenose dolphin Gulf of America, Western Coastal 23 (16-32) 1 (1-2) 10 (5-15) 8 (3-13) −5 (3-9) N/A Shelf dolphins ** Multiple 13 (9-19) 4 (2-6) 6 (3-8) 5 (2-7) −3 N/A Clymene dolphin Northern Gulf of America 7 (3-15) 2 (1-4) 3 (2-5) 3 (1-4) −3 N/A False killer whale Northern Gulf of America 18 (7-48) 6 (3-9) 8 (4-12) 7 (3-11) −9 42 Melon-headed whale Northern Gulf of America 15 (6-36) 5 (2-7) 7 (3-10) 6 (2-9) −7 29 Pantropical spotted dolphin Northern Gulf of America 20 (15-26) 7 (3-10) 9 (4-13) 7 (3-11) −9 39 Pygmy killer whale Northern Gulf of America 15 (7-33) 5 (2-8) 7 (3-10) 6 (2-9) −7 29 Risso's dolphin Northern Gulf of America 8 (5-13) 3 (1-4) 3 (2-5) 3 (1-4) −3

eys and the species could not generally be distinguished from the air. However, a recent study by Frasier et al. (2024), using a widely-spaced passive acoustic monitoring array, found that of eight groups monitored from 2010-2020, seven groups experienced long-term density declines, including beaked whales (up to 83 percent), small delphinids (up to 43 percent), and sperm whales (up to 31 percent). These measured density declines exceed model-predicted changes and do not suggest recovery trends for affected species to date (Frasier et al., 2024). Population consequences of 15 cetacean taxonomic units in pelagic and continental shelf waters (not including killer whales, false killer whales, and Fraser's dolphins) were assessed by Marques et al. (2023), who found that the DWH oil spill had the greatest population impacts on spinner dolphins, striped dolphins, sperm whales, oceanic bottlenose dolphins, and Kogia species. The number of lost cetacean years was highest for the shelf bottlenose dolphin population (32,584 years) and pantropical spotted dolphin population (31,372 years) (Marques et al., 2023).

Marine Mammal Hearing

Hearing is the most important sensory modality for marine mammals underwater, and exposure to anthropogenic sound can have deleterious effects. To appropriately assess the potential effects of exposure to sound, it is necessary to understand the frequency ranges marine mammals are able to hear. Not all marine mammal species have equal hearing capabilities ( e.g., Richardson et al., 1995, Wartzok and Ketten, 1999, Au and Hastings, 2008). To reflect this, Southall et al. (2007), Southall et al. (2019) recommended that marine mammals be divided into hearing groups based on directly measured (behavioral or auditory evoked potential techniques) or estimated hearing ranges ( e.g., behavioral response data, anatomical modeling)

adjusted these hearing groups using data from recent hearing measurements in minke whales (Houser et al., 2024). These data support separating mysticetes (the LF cetacean marine mammal hearing group in table 16) into two hearing groups, which the Navy designates as “very low-frequency (VLF) cetaceans” and “low-frequency (LF) cetaceans,” which follows the recommendations of Southall et al. (2019a). Within the Navy's adjusted hearing groups, the VLF cetacean group contains the larger mysticetes (blue, fin, right, and bowhead whales) and the LF cetacean group contains the mysticete species not included in the VLF group ( e.g., minke, humpback, gray, pygmy right whales). Although there have been no direct measurements of hearing sensitivity in the larger mysticetes included in Navy's VLF hearing group, an audible frequency range of approximately 10 Hz to 30 kHz has been estimated from measured vocalization frequencies, observed responses to playback of sounds, and anatomical analyses of the auditory system. The upper frequency limit of hearing in Navy's LF hearing group has been estimated in a minke whale from direct measurements of auditory evoked potentials (Houser et al., 2024).

Potential Effects of Specified Activities on Marine Mammals and Their Habitat

This section provides a discussion of the ways in which components of the specified activity may impact marine mammals and their habitat. The Estimated Take of Marine Mammals section later in this document includes a quantitative analysis of the number of individuals that are expected to be taken by this activity

4).

Potential Effects of Specified Activities on Marine Mammals and Their Habitat

This section provides a discussion of the ways in which components of the specified activity may impact marine mammals and their habitat. The Estimated Take of Marine Mammals section later in this document includes a quantitative analysis of the number of individuals that are expected to be taken by this activity. The Preliminary Analysis and Negligible Impact Determination section considers the content of this section, the Estimated Take of Marine Mammals section, and the Proposed Mitigation Measures section, to draw conclusions regarding the likely impacts of these activities on the reproductive success or survivorship of individuals and whether those impacts on individuals are likely to adversely affect the species through effects on annual rates of recruitment or survival.

The Action Proponents have requested authorization for the take of marine mammals that may occur incidental to training and testing activities in the AFTT Study Area. The Action Proponents analyzed potential impacts to marine mammals from acoustic and explosive sources and from vessel use in the application. NMFS carefully reviewed the information provided by the Action Proponents and concurs with their synthesis of science, along with independently reviewing applicable scientific research and literature and other information to evaluate the potential effects of the Action Proponents' activities on marine mammals, which are presented in this section (see appendix D in the 2024 AFTT Draft Supplemental EIS/OEIS for additional information).

Other potential impacts to marine mammals from training and testing activities in the AFTT Study Area were analyzed in the 2024 AFTT Draft Supplemental EIS/OEIS, in consultation with NMFS as a cooperating agency, and determined to be unlikely to result in marine mammal take

ich are presented in this section (see appendix D in the 2024 AFTT Draft Supplemental EIS/OEIS for additional information).

Other potential impacts to marine mammals from training and testing activities in the AFTT Study Area were analyzed in the 2024 AFTT Draft Supplemental EIS/OEIS, in consultation with NMFS as a cooperating agency, and determined to be unlikely to result in marine mammal take. Therefore, the Action Proponents have not requested authorization for take of marine mammals incidental to other components of their proposed Specified Activities, and we agree that incidental take is unlikely to occur from those components. In this proposed rule, NMFS analyzes the potential effects on marine mammals from the activity components that may cause the take of marine mammals: exposure to acoustic or explosive stressors including non-impulsive (sonar and other transducers, and vibratory pile driving) and impulsive (explosives, impact pile driving, and air guns) stressors and vessel movement.

For the purpose of MMPA incidental take authorizations, NMFS' effects assessments serve four primary purposes: (1) to determine whether the specified activities would have a negligible impact on the affected species or stocks of marine mammals (based on whether it is likely that the activities would adversely affect the species or stocks through effects on annual rates of recruitment or survival); (2) to determine whether the specified activities would have an unmitigable adverse impact on the availability of the species or stocks for subsistence uses; (3) to prescribe the permissible methods of taking ( i.e., Level B harassment (behavioral harassment and temporary threshold shift (TTS)), Level A harassment (auditory (AUD INJ) and non-auditory injury), serious injury, or mortality), including identification of the number and types of take that could occur by harassment, serious injury, or mortality, and to prescribe other means of effecting the least practicable adverse impact on the species or stocks and their habitat

es whether the proposed authorized take would have a negligible impact on the affected species and stocks.

Potential Effects of Underwater Sound on Marine Mammals

The marine soundscape is comprised of both ambient and anthropogenic sounds. Ambient sound is defined as the all-encompassing sound in a given place and is usually a composite of sound from many sources both near and far (ANSI, 1995). The sound level of an area is defined by the total acoustical energy being generated by known and unknown sources, which may include physical ( e.g., waves, wind, precipitation, earthquakes, ice, atmospheric sound), biological ( e.g., sounds produced by marine mammals, fish, and invertebrates), and anthropogenic sound ( e.g., vessels, dredging, aircraft, construction).

The sum of the various natural and anthropogenic sound sources at any given location and time—which comprise “ambient” or “background” sound—depends not only on the source levels (as determined by current weather conditions and levels of biological and shipping activity) but also on the ability of sound to propagate through the environment. In turn, sound propagation is dependent on the spatially and temporally varying properties of the water column and sea floor and is frequency-dependent. As a result of the dependence on a large number of varying factors, ambient sound levels can be expected to vary widely over both coarse and fine spatial and temporal scales. Sound levels at a given frequency and location can vary by 10-20 dB from day to day (Richardson et al., 1995). The result is that, depending on the source type and its intensity, sound from the specified activities may be a negligible addition to the local environment or could form a distinctive signal that may affect marine mammals

Richardson et al. (1995) described zones of increasing intensity of effect that might be expected to occur, in relation to distance from a source and assuming that the signal is within an animal's hearing range. First is the area within which the acoustic signal would be audible (potentially perceived) to the animal, but not strong enough to elicit any overt behavioral or physiological response. The next zone corresponds with the area where the signal is audible to the animal and of sufficient intensity to elicit behavioral or physiological responsiveness. Third is a zone within which, for signals of high intensity, the received level is sufficient to potentially cause discomfort or non-auditory injury to auditory systems. Overlaying these zones to a certain extent is the area within which masking ( i.e., when a sound interferes with or masks the ability of an animal to detect a signal of interest that is above the absolute hearing threshold) may occur; the masking zone may be highly variable in size.

We also describe more severe potential effects ( i.e., certain non-auditory physical or physiological effects). Potential effects from impulsive sound sources can range in severity from effects such as behavioral disturbance or tactile perception to physical discomfort, slight injury of the internal organs and the auditory system, or, in the case of explosives, more severe injuries or mortality (Yelverton et al., 1973). Non-auditory physiological effects or injuries that theoretically might occur in marine mammals exposed to high levels of underwater sound or as a secondary effect of extreme behavioral responses ( e.g., change in dive profile as a result of an avoidance response) caused by exposure to sound include neurological effects, bubble formation, resonance effects, and other types of organ or non-auditory injury (Cox et al., 2006; Southall et al., 2007; Zimmer and Tyack, 2007; Tal et al., 2015)

s' hearing range when species-specific hearing data are not available ( e.g., large whale species).

Hearing Loss and Auditory Injury

Marine mammals, like all mammals, lose their ability to hear over time due to age-related degeneration of auditory pathways and sensory cells of the inner ear. This natural, age-related hearing loss is distinct from acute noise-induced hearing loss (Møller, 2013). Noise-induced hearing loss can be temporary ( i.e., TTS) or permanent (permanent threshold shift, PTS), and higher-level sound exposures are more likely to cause PTS or other AUD INJ. For marine mammals, AUD INJ is considered to be possible when sound exposures are sufficient to produce 40 dB of TTS measured approximately 4 minutes after exposure (U.S. Department of the Navy, 2024). Numerous studies have directly examined noise-induced hearing loss in marine mammals by measuring an animal's hearing threshold before and after exposure to intense sounds. The difference between the post-exposure and pre-exposure hearing thresholds is then used to determine the amount of TTS (in dB) that was produced as a result of the sound exposure (see appendix D of the 2024 AFTT Draft Supplemental EIS/OEIS for additional details). The Navy used these studies to generate exposure functions, which are predictions of the onset of TTS or PTS based on sound frequency, level, and type (continuous or impulsive), for each marine mammal functional hearing group (U.S. Department of the Navy, 2024).

TTS can last from minutes or hours to days ( i.e., there is recovery back to baseline/pre-exposure hearing threshold), can occur within a specific frequency range ( i.e., an animal might only have a temporary loss of hearing sensitivity within a limited frequency band of its auditory range), and can be of varying amounts ( e.g., an animal's hearing sensitivity might be reduced by only 6 dB or reduced by 30 dB)

a role in inducing auditory threshold shift: effects to sensory hair cells in the inner ear that reduce their sensitivity; modification of the chemical environment within the sensory cells; residual muscular activity in the middle ear; displacement of certain inner ear membranes; increased blood flow; and post-stimulatory reduction in both efferent and sensory neural output (Southall et al., 2007). The amplitude, duration, frequency, temporal pattern, and energy distribution of sound exposure all can affect the amount of associated threshold shift and the frequency range in which it occurs. Generally, the amount of threshold shift, and the time needed to recover from the effect, increase as amplitude and duration of sound exposure increases. Human non-impulsive noise exposure guidelines are based on the assumption that exposures of equal energy (the same SEL) produce equal amounts of hearing impairment regardless of how the sound energy is distributed in time (NIOSH, 1998). Previous marine mammal TTS studies have also generally supported this equal energy relationship (Southall et al., 2007). SEL is used to predict TTS in marine mammals and is considered a good predictor of TTS for shorter duration exposures than longer duration exposures. The amount of TTS increases with exposure SPL and duration, and is correlated with SEL, but duration of the exposure has a more significant effect on TTS than would be predicted based on SEL alone ( e.g., Finneran et al., 2010b; Kastak et al., 2007; Kastak et al., 2005; Kastelein et al., 2014a; Mooney et al., 2009a; Popov et al., 2014; Gransier and Kastelein, 2024). These studies highlight the inherent complexity of predicting TTS onset in marine mammals, as well as the importance of considering exposure duration when assessing potential impacts.

Generally, TTS increases with SEL in a non-linear fashion, where lower SEL exposures will elicit a steady rate of TTS increase while higher SEL

exposures will either increase TTS more rapidly or plateau (Finneran, 2015; U.S

al., 2007; Southall et al., 2019c; U.S. Department of the Navy, 2024a).

In some cases, intense noise exposures have caused AUD INJ ( e.g., loss of cochlear neuron synapses), despite thresholds eventually returning to normal; i.e., it is possible to have AUD INJ without a resulting PTS ( e.g., Kujawa and Liberman, 2006, 2009; Kujawa, 2010; Fernandez et al., 2015; Ryan et al., 2016; Houser, 2021). In these situations, however, threshold shifts were 30-50 dB measured 24 hours after the exposure; i.e., there is no evidence that an exposure resulting in less than 40 dB TTS measured a few minutes after exposure can produce AUD INJ. Therefore, an exposure producing 40 dB of TTS, measured a few minutes after exposure, can also be used as an upper limit to prevent AUD INJ; i.e., it is assumed that exposures beyond those capable of causing 40 dB of TTS have the potential to result in INJ (which may or may not result in PTS).

Irreparable damage to the inner or outer cochlear hair cells may cause PTS; however, other mechanisms are also involved, such as exceeding the elastic limits of certain tissues and membranes in the middle and inner ears and resultant changes in the chemical composition of the inner ear fluids (Southall et al., 2007). When AUD INJ occurs, there is physical damage to the sound receptors in the ear, whereas TTS represents primarily tissue fatigue and is reversible (Southall et al., 2007). AUD INJ is permanent ( i.e., there is incomplete recovery back to baseline/pre-exposure levels) but also can occur in a specific frequency range and amount as mentioned above for TTS. In addition, other investigators have suggested that TTS is within the normal bounds of physiological variability and tolerance and does not represent physical injury ( e.g., Ward, 1997). Therefore, NMFS does not consider less than 40 dB of TTS to constitute AUD INJ

earing may affect the resulting amount of measured TTS, with neurophysiological measures producing larger amounts of TTS compared to psychophysical measures (Finneran et al., 2007; Finneran, 2015; Finneran et al., 2023).

• The amount of TTS varies with the hearing test frequency. As the exposure SPL increases, the frequency at which the maximum TTS occurs also increases (Kastelein et al., 2014b). For high-level exposures, the maximum TTS typically occurs one-half to one octave above the exposure frequency (Finneran et al., 2007; Mooney et al., 2009a; Nachtigall et al., 2004; Popov et al., 2011; Popov et al., 2013; Schlundt et al., 2000). The overall spread of TTS from tonal exposures can therefore extend over a large frequency range ( i.e., narrowband exposures can produce broadband (greater than one octave) TTS).

• The amount of TTS increases with exposure SPL and duration and is correlated with SEL, especially if the range of exposure durations is relatively small (Kastak et al., 2007; Kastelein et al., 2014b; Popov et al., 2014). As the exposure duration increases, however, the relationship between TTS and SEL begins to break down. Specifically, duration has a more significant effect on TTS than would be predicted on the basis of SEL alone (Finneran et al., 2010a; Kastak et al., 2005; Mooney et al., 2009a). This means if two exposures have the same SEL but different durations, the exposure with the longer duration (thus lower SPL) will tend to produce more TTS than the exposure with the higher SPL and shorter duration. In most acoustic impact assessments, the scenarios of interest involve shorter duration exposures than the marine mammal experimental data from which impact thresholds are derived; therefore, use of SEL tends to

over-estimate the amount of TTS. Despite this, SEL continues to be used in many situations because it is relatively simple, more accurate than SPL alone, and lends itself easily to scenarios involving multiple exposures with different SPL (Finneran, 2015)

t al., 2015b; Mooney et al., 2009b). This means that TTS predictions based on the total, cumulative SEL will overestimate the amount of TTS from intermittent exposures such as sonars and impulsive sources.

• The amount of observed TTS tends to decrease with increasing time following the exposure; however, the relationship is not monotonic ( i.e., increasing exposure does not always increase TTS). The time required for complete recovery of hearing depends on the magnitude of the initial shift; for relatively small shifts recovery may be complete in a few minutes, while large shifts ( e.g., approximately 40 dB) may require several days for recovery. Under many circumstances TTS recovers linearly with the logarithm of time (Finneran et al., 2010a, 2010b; Finneran and Schlundt, 2013; Kastelein et al., 2012a; Kastelein et al., 2012b; Kastelein et al., 2013a; Kastelein et al., 2014b; Kastelein et al., 2014c; Popov et al., 2011; Popov et al., 2013; Popov et al., 2014). This means that for each doubling of recovery time, the amount of TTS will decrease by the same amount ( e.g., 6 dB recovery per doubling of time).

Nachtigall et al. (2018) and Finneran (2018) describe the measurements of hearing sensitivity of multiple odontocete species (bottlenose dolphin, harbor porpoise, beluga, and false killer whale) when a relatively loud sound was preceded by a warning sound. These captive animals were shown to reduce hearing sensitivity when warned of an impending intense sound. Based on these experimental observations of captive animals, the authors suggest that wild animals may dampen their hearing during prolonged exposures or if conditioned to anticipate intense sounds. Finneran (2018) recommends further investigation of the mechanisms of hearing sensitivity reduction in order to understand the implications for interpretation of existing TTS data obtained from captive animals, notably for considering TTS due to short duration, unpredictable exposures

t wild animals may dampen their hearing during prolonged exposures or if conditioned to anticipate intense sounds. Finneran (2018) recommends further investigation of the mechanisms of hearing sensitivity reduction in order to understand the implications for interpretation of existing TTS data obtained from captive animals, notably for considering TTS due to short duration, unpredictable exposures.

Marine mammal hearing plays a critical role in communication with conspecifics and in interpretation of environmental cues for purposes such as predator avoidance and prey capture. Depending on the degree (elevation of threshold in dB), duration ( i.e., recovery time), and frequency range of TTS, and the context in which it is experienced, TTS can have effects on marine mammals ranging from discountable to serious similar to those discussed in auditory masking, below. For example, a marine mammal may be able to readily compensate for a brief, relatively small amount of TTS in a non-critical frequency range that takes place during a time where ambient noise is lower and there are not as many competing sounds present. Alternatively, a larger amount and longer duration of TTS sustained during a time when communication is critical for successful mother/calf interactions could have more serious impacts if it were in the same frequency band as the necessary vocalizations and of a severity that impeded communication. The fact that animals exposed to high levels of sound that would be expected to result in this physiological response would also be expected to have behavioral responses of a comparatively more severe or sustained nature is potentially more significant than the simple existence of a TTS. However, it is important to note that TTS could occur due to longer exposures to sound at lower levels so that a behavioral response may not be elicited

els of sound that would be expected to result in this physiological response would also be expected to have behavioral responses of a comparatively more severe or sustained nature is potentially more significant than the simple existence of a TTS. However, it is important to note that TTS could occur due to longer exposures to sound at lower levels so that a behavioral response may not be elicited.

Depending on the degree and frequency range, the effects of AUD INJ on an animal could also range in severity, although it is considered generally more serious than TTS because it is a permanent condition (Reichmuth et al., 2019). Of note, reduced hearing sensitivity as a simple function of aging has been observed in marine mammals, as well as humans and other taxa (Southall et al., 2007), so we can infer that strategies exist for coping with this condition to some degree, though likely not without some cost to the animal.

As the amount of research on hearing sensitivity has grown, so, too, has the understanding that marine mammals may be able to self-mitigate, or protect, against noise-induced hearing loss. An animal may learn to reduce or suppress their hearing sensitivity when warned of an impending intense sound exposure, or if the duty cycle of the sound source is predictable (Finneran, 2018; Finneran et al., 2024; Nachtigall and Supin, 2013, 2014, 2015; Nachtigall et al., 2015; Nachtigall et al., 2016a, 2018; Nachtigall et al., 2016b). This has been shown with several species, including the false killer whale (Nachtigall and Supin, 2013), bottlenose dolphin (Finneran, 2018; Nachtigall and Supin, 2014, 2015; Nachtigall et al., 2016b), beluga whale (Nachtigall et al., 2015), and harbor porpoise (Nachtigall et al., 2016a). Additionally, Finneran et al. (2023) and Finneran et al. (2024) found that odontocetes that had participated in TTS experiments in the past could have learned from that experience and subsequently protected their hearing during new sound exposure experiments

4-9.5 km) away. Importantly, this study also showed that whales exposed to a similar range of received levels (78-106 dB re 1 µPa) from distant sonar exercises 73.3 mi (118 km away) did not elicit such responses, suggesting that context may moderate responses.

Ellison et al. (2012) outlined an approach to assessing the effects of sound on marine mammals that incorporates contextual-based factors. The authors recommend considering not just the received level of sound, but also the activity the animal is engaged in at the time the sound is received, the nature and novelty of the sound ( i.e., is this a new sound from the animal's perspective), and the distance between the sound source and the animal. They submit that this “exposure context,” as described, greatly influences the type of behavioral response exhibited by the animal. Forney et al. (2017) also point out that an apparent lack of response ( e.g., no displacement or avoidance of a sound source) may not necessarily mean there is no cost to the individual or population, as some resources or habitats may be of such high value that animals may choose to stay, even when experiencing stress or hearing loss. Forney et al. (2017) recommend considering both the costs of remaining in an area of noise exposure such as TTS, PTS, or masking, which could lead to an increased risk of predation or other threats or a decreased capability to forage, and the costs of displacement, including potential increased risk of vessel strike, increased risks of predation or competition for resources, or decreased habitat suitable for foraging, resting, or socializing. This sort of contextual information is challenging to predict with accuracy for ongoing activities that occur over large spatial and temporal expanses. However, distance is one contextual factor for which data exist to quantitatively inform a take estimate, and the method for predicting Level B harassment in this rule does consider distance to the source

able for foraging, resting, or socializing. This sort of contextual information is challenging to predict with accuracy for ongoing activities that occur over large spatial and temporal expanses. However, distance is one contextual factor for which data exist to quantitatively inform a take estimate, and the method for predicting Level B harassment in this rule does consider distance to the source. Other factors are often considered qualitatively in the analysis of the likely consequences of sound exposure, where supporting information is available.

Friedlaender et al. (2016) provided the first integration of direct measures of prey distribution and density variables incorporated into across-individual analyses of behavior responses of blue whales to sonar, and demonstrated a five-fold increase in the ability to quantify variability in blue whale diving behavior. These results illustrate that responses evaluated without such measurements for foraging animals may be misleading, which again illustrates the context-dependent nature of the probability of response.

Exposure of marine mammals to sound sources can result in, but is not limited to, no response or any of the following observable responses: increased alertness; orientation or attraction to a sound source; vocal modifications; cessation of feeding; cessation of social interaction; alteration of movement or diving behavior; habitat abandonment (temporary or permanent); and, in severe cases, panic, flight, stampede, or stranding, potentially resulting in death (Southall et al., 2007). A review of marine mammal responses to anthropogenic sound was first conducted by Richardson (1995). More recent reviews (Nowacek et al., 2007; DeRuiter et al., 2012 and 2013; Ellison et al., 2012; Gomez et al., 2016) address studies conducted since 1995 and focused on observations where the received sound level of the exposed marine mammal(s) was known or could be estimated. Gomez et al

ely and another animal starting to forage during the exposure (Sivle et al., 2016). In addition, almost half of the animals that exhibited avoidance behavior were foraging before the exposure, but the others were not; the animals that exhibited avoidance behavior while not feeding responded at a slightly lower received level and greater distance than those that were feeding (Wensveen et al., 2017). These findings indicate that the behavioral state of the animal plays a role in the type and severity of a behavioral response. Henderson et al. (2019) examined tagged humpback whale dive and movement behavior, including individuals incidentally exposed to Navy sonar during training activities, at the Pacific Missile Range Facility off Kaua'i, Hawaii. Tracking data showed that, regardless of exposure to sonar, individual humpbacks spent limited time, no more than a few days, in the vicinity of Kaua'i. Potential behavioral responses due to sonar exposure were limited and may have been influenced by breeding and social behaviors. Martin et al. (2015) found that the density of calling minke whales was reduced during periods of Navy training involving sonar relative to the periods before training began and increased again in the days following the completion of training activities. The responses of individual whales could not be assessed, so in this case it is unknown whether the decrease in calling animals indicated that the animals left the range or simply ceased calling. Harris et al. (2019b) utilized acoustically generated minke whale tracks to statistically demonstrate changes in the spatial distribution of minke whale acoustic presence before, during, and after surface ship MFAS training. The spatial distribution of probability of acoustic presence was different in the “during” phase compared to the “before” phase, and the probability of presence at the center of ship activity during MFAS training was close to zero for both years

ks to statistically demonstrate changes in the spatial distribution of minke whale acoustic presence before, during, and after surface ship MFAS training. The spatial distribution of probability of acoustic presence was different in the “during” phase compared to the “before” phase, and the probability of presence at the center of ship activity during MFAS training was close to zero for both years. The “after” phases for both years retained lower probabilities of presence suggesting the return to baseline conditions may take more than five days. The results show a clear spatial redistribution of calling minke whales during surface ship MFAS training, however a limitation of passive acoustic monitoring is that one cannot conclude if the whales moved away, went silent, or a combination of the two.

Building on this work, Durbach et al. (2021) used the same data and determined that individual minke whales tended to be in either a fast or slow movement behavior state while on the missile range, where whales tended to be in the slow state in baseline or before periods but transitioned into the fast state with more directed movement during sonar exposures. They also moved away from the area of sonar activity on the range, either to the north or east depending on where the activity was located; this explains the spatial redistribution found by Harris et al. (2019b). Minke whales were also more likely to stop calling when in the fast state, regardless of sonar activity, or when in the slow state during sonar activity (Durbach et al., 2021). Similarly, minke whale detections were reduced or ceased altogether during periods of sonar use off Jacksonville, Florida, (Norris et al., 2012; Simeone et al., 2015; U.S. Department of the Navy, 2013), especially with an increased ping rate (Charif et al., 2015).

Odontocetes have varied, context-dependent behavioral responses to sonar and other transducers

sonar activity (Durbach et al., 2021). Similarly, minke whale detections were reduced or ceased altogether during periods of sonar use off Jacksonville, Florida, (Norris et al., 2012; Simeone et al., 2015; U.S. Department of the Navy, 2013), especially with an increased ping rate (Charif et al., 2015).

Odontocetes have varied, context-dependent behavioral responses to sonar and other transducers. Much of the research on odontocetes has been focused on understanding the impacts of sonar and other transducers on beaked whales because they were hypothesized to be more susceptible to behavioral disturbance after several strandings of beaked whales in which military MFAS was identified as a contributing factor (see Stranding and Mortality section). Subsequent BRSs have shown beaked whales are likely more sensitive to disturbance than most other cetaceans. Many species of odontocetes have been studied during BRSs, including Blainville's beaked whale, goose-beaked whale, Baird's beaked whale, northern bottlenose whale, harbor porpoise, pilot whale, killer whale, sperm whale, false killer whale, melon-headed whale, bottlenose dolphin, rough-toothed dolphin, Risso's dolphin, Pacific white-sided dolphin, and Commerson's dolphin. Observed responses by Blainville's beaked whales, goose-beaked whales, Baird's beaked whales, and northern bottlenose whales (the largest of the beaked whales), to mid-frequency sonar sounds include cessation of clicking, decline in group vocal periods, termination of foraging dives, changes in direction to avoid the sound source, slower ascent rates to the surface, longer deep and shallow dive durations, and other unusual dive behaviors (DeRuiter et al., 2013b; Hewitt et al., 2022; Jacobson et al., 2022; McCarthy et al., 2011; Miller et al., 2015; Moretti et al., 2014; Southall et al., 2011; Stimpert et al., 2014; Tyack et al., 2011)

al periods, termination of foraging dives, changes in direction to avoid the sound source, slower ascent rates to the surface, longer deep and shallow dive durations, and other unusual dive behaviors (DeRuiter et al., 2013b; Hewitt et al., 2022; Jacobson et al., 2022; McCarthy et al., 2011; Miller et al., 2015; Moretti et al., 2014; Southall et al., 2011; Stimpert et al., 2014; Tyack et al., 2011).

During a BRS in Southern California, a tagged Baird's beaked whale exposed to simulated MFA sonar within 3 km increased swim speed and modified its dive behavior (Stimpert et al., 2014). One goose-beaked whale was also incidentally exposed to real Navy sonar located over 62.1 mi (100 km) away in addition to the source used in the controlled exposure study, and the authors did not detect similar responses at comparable received levels. Received levels from the MFA sonar signals from the controlled (2.1 to 5.9 mi (3.4 to 9.5 km)) exposures were calculated as 84-144 dB re 1 μPa, and incidental (73.3 mi (118 km)) exposures were calculated as 78-106 dB re 1 μPa, indicating that context of the exposures ( e.g., source proximity, controlled source ramp-up) may have been a significant factor in the responses to the simulated sonars (DeRuiter et al., 2013b).

Long-term tagging work during the same BRS demonstrated that the longer duration dives considered a behavioral response by DeRuiter et al. (2013b) fell within the normal range of dive durations found for eight tagged goose-beaked whales on the Southern California Offshore Range (Schorr et al., 2014). However, the longer inter-deep dive intervals found by DeRuiter et al. (2013b), which were among the longest found by Schorr et al. (2014) and Falcone et al. (2017), may indicate a response to sonar. Williams et al. (2017) note that during normal deep dives or during fast swim speeds, beaked whales and other marine mammals use strategies to reduce their stroke rates ( e.g., leaping, wave surfing when swimming, interspersing glides between bouts of stroking when diving)

013b), which were among the longest found by Schorr et al. (2014) and Falcone et al. (2017), may indicate a response to sonar. Williams et al. (2017) note that during normal deep dives or during fast swim speeds, beaked whales and other marine mammals use strategies to reduce their stroke rates ( e.g., leaping, wave surfing when swimming, interspersing glides between bouts of stroking when diving). The authors determined that in the post-exposure dives by the tagged goose-beaked whales described in DeRuiter et al. (2013b), the whales ceased gliding and swam with almost continuous strokes. This change in swim behavior was calculated to increase metabolic costs about 30.5 percent and increase the amount of energy expending on fast swim speeds from 27-59 percent of their overall energy budget. This repartitioning of energy was detected in the model up to 1.7 hours after the single sonar exposure. Therefore, while the overall post-exposure dive durations were similar, the metabolic energy calculated by Williams et al. (2017) was higher. However, Southall et al. (2019a) found that prey availability was higher in the western area of the Southern California Offshore Range where goose-beaked whales preferentially occurred, while prey resources were lower in the eastern area and moderate in the area just north of the Range. This high prey availability may indicate that goose-beaked whales need fewer foraging dives to meet energy requirements than would be needed in another area with fewer resources.

During a BRS in Norway, northern bottlenose whales avoided a sonar sound source over a wide range of distances (0.5 to 17.4 mi (0.8 to 28 km)) and estimated avoidance thresholds ranging from received SPLs of 117 to 126 dB re 1 μPa

within 1.2 to 18 mi (2 to 29 km) of the AUTEC range at the onset of active sonar were displaced a maximum of 17.4 to 42.3 mi (28 to 68 km) after moving away from the range, although one individual did approach the range during active sonar use. Researchers found a decline in deep dives at the onset of the training and an increase in time spent on foraging dives as whales moved away from the range. Predicted received levels at which presumed responses were observed were comparable to those previously observed in beaked whale studies. Acoustic data indicated that vocal periods were detected on the range within 72 hours after training ended (Joyce et al., 2019). However, Blainville's beaked whales have been documented to remain on-range to forage throughout the year (Henderson et al., 2016), indicating the AUTEC range may be a preferred foraging habitat regardless of the effects of active sonar noise, or it could be that there are no long-term consequences of the sonar activity. In the SOCAL Range Complex, researchers conducting photo-identification studies have identified approximately 100 individual goose-beaked whales, with 40 percent having been seen in one or more prior years, with re-sightings up to 7 years apart, indicating a possible on-range resident population (Falcone & Schorr, 2014; Falcone et al., 2009).

The probability of Blainville's beaked whale group vocal periods on the Pacific Missile Range Facility were modeled during periods of (1) no naval activity, (2) naval activity without hull-mounted MFA sonar, and (3) naval activity with hull-mounted MFA sonar (Jacobson et al., 2022). At a received level of 150 dB re 1 μPa RMS, the probability of detecting a group vocal period during MFA sonar use decreased by 77 percent compared to periods when general training activity was ongoing, and by 87 percent compared to baseline (no naval activity) conditions

(2) naval activity without hull-mounted MFA sonar, and (3) naval activity with hull-mounted MFA sonar (Jacobson et al., 2022). At a received level of 150 dB re 1 μPa RMS, the probability of detecting a group vocal period during MFA sonar use decreased by 77 percent compared to periods when general training activity was ongoing, and by 87 percent compared to baseline (no naval activity) conditions. Jacobsen et al (2022) found a greater reduction in probability of a group vocal period with MFA sonar than observed in a prior study of the same species at the AUTEC range (Moretti et al., 2014), which may be due to the baseline period in the AUTEC study including naval activity without MFA sonar, potentially lowering the baseline group vocal period activity in that study, or due to differences in the residency of the populations at each range.

Stanistreet et al. (2022) used passive acoustic recordings during a multinational navy activity to assess marine mammal acoustic presence and behavioral response to especially long bouts of sonar lasting up to 13 consecutive hours, occurring repeatedly over 8 days (median and maximum SPL = 120 dB and 164 dB). Goose-beaked whales and sperm whales substantially reduced how often they produced clicks during sonar, indicating a decrease or cessation in foraging behavior. Few previous studies have shown sustained changes in foraging or displacement of sperm whales, but there was an absence of sperm whale clicks for 6 consecutive days of sonar activity. Sperm whales returned to baseline levels of clicks within days after the activity, but beaked whale detection rates remained low even 7 days after the exercise. In addition, there were no detections from a Mesoplodon beaked whale species within the area during, and at least 7 days after, the sonar activity. Clicks from northern bottlenose whales and Sowerby's beaked whales were also detected but were not frequent enough at the recording site used to compare clicks between baseline and sonar conditions

MFA sonar at closer ranges were comparable to the responses to the higher source level vessel sonar, as was the context of the exposure. Helicopter dipping sonars are shorter duration and randomly located, therefore more difficult to predict or track by beaked whales and potentially more likely to elicit a response, especially at closer distances (3.7 to 15.5 mi (6 to 25 km))(Falcone et al., 2017). Sea floor depths and quantity of light ( i.e., lunar cycle) are also important variables to consider in BRSs, as goose-beaked whale foraging dive depth increased with sea floor depth (maximum 6,561.7 ft (2,000 m)) and the amount of time spent at foraging depths (and likely foraging) was greater at night (likely avoiding predation by staying deeper during periods of bright lunar illumination), although they spent more time near the surface during the night, as well, particularly on dark nights with little moonlight, (Barlow et al., 2020). Sonar occurred during 10 percent of the dives studied and had little effect on the resulting dive metrics. Watwood et al. (2017) found that the longer the duration of a sonar event, the greater reduction in detected goose-beaked whale group dives and, as helicopter dipping events occurred more frequently but with shorter durations than periods of hull-mounted sonar, when looking at the number of detected group dives there was a greater reduction during periods of hull-mounted sonar than during helicopter dipping sonar. DiMarzio et al. (2019) also found that group vocal periods ( i.e., clusters of foraging pulses), on average, decreased during sonar events on the Southern California Anti-Submarine Warfare Range, though the decline from before the event to during the event was significantly less for helicopter dipping events than hull-mounted events, and there was no difference in the magnitude of the decline between vessel-only events and events with both vessels and helicopters. Manzano-Roth et al

pulses), on average, decreased during sonar events on the Southern California Anti-Submarine Warfare Range, though the decline from before the event to during the event was significantly less for helicopter dipping events than hull-mounted events, and there was no difference in the magnitude of the decline between vessel-only events and events with both vessels and helicopters. Manzano-Roth et al. (2022) analyzed long-term passive acoustic monitoring data from the Pacific Missile Range Facility in Kaua'i, Hawaii, and found beaked whales reduced group vocal periods during submarine command course events and remained low for a minimum of 3 days after the MFA sonar activity.

Harbor porpoise behavioral responses have been researched extensively using acoustic deterrent and acoustic harassment devices; however, BRSs using sonar are limited. Kastelein et al. (2018b) found harbor porpoises did not respond to low-duty cycle mid-frequency sonar tones (3.5-4.1 kHz at 2.7 percent duty cycle; e.g., one tone per minute) at any received level, but one individual did respond ( i.e., increased jumping, increased respiration rates) to high-duty cycle sonar tones (3.5-4.1 kHz at 96 percent duty cycle; e.g., continuous tone for almost a minute).

Behavioral responses by odontocetes (other than beaked whales and harbor porpoises) to sonar and other transducers include horizontal avoidance, reduced breathing rates, changes in behavioral state, changes in dive behavior (Antunes et al., 2014; Isojunno et al., 2018; Isojunno et al., 2017; Isojunno et al., 2020; Miller, 2012; Miller et al., 2011; Miller et al., 2014), and, in one study, separation of a killer whale calf from its group (Miller et al., 2011). Some species of dolphin ( e.g., bottlenose, spotted, spinner, Clymene, Pacific white-sided, rough-toothed) are frequently documented bowriding with vessels and the drive to engage in bowriding, whether for pleasure or energetic savings (Fiori et al., 2024) may supersede the impact of associated sonar noise (Würsig et al., 1998)

dB re 1 μPa, and beluga whales did so at received levels of 180-196 dB re 1 μPa and above.

While several opportunistic observations of odontocete (other than beaked whales and harbor porpoises) responses have been recorded during previous Navy activities and BRSs that employed sonar and sonar-like sources, it is difficult to definitively attribute responses of non-focal species to sonar exposure. Responses range from no response to potential highlight-impactful responses, such as the separation of a killer whale calf from its group (Miller et al., 2011). This may be due, in part, to the variety of species and sensitivities of the odontocete taxonomic group, as well as the breadth of study types conducted and field observations, leading to the assessment of both contextually driven and dose-based responses. The available data indicate exposures to sonar in close proximity and with multiple vessels approaching an animal likely lead to higher-level responses by most odontocete species, regardless of received level or behavioral state. However, when sources are further away and moving in variable directions, behavioral responses are likely driven by behavioral state, individual experience, or species-level sensitivities, as well as exposure duration and received level, with the likelihood of response increasing with increased received levels. As such, it is expected odontocete behavioral responses to sonar and other transducers will vary by species, populations, and individuals, and long-term consequences or population-level effects are likely dependent upon the frequency and duration of the exposure and resulting behavioral response.

Pinniped behavioral response to sonar and other transducers is context-dependent ( e.g., Hastie et al., 2014; Southall et al., 2019)

137 dB re 1 µPa by hauling out more, swimming faster, and raising their heads or jumping out of the water. However, seals did not respond to a continuous wave or combination signals at any received level (up to 156 dB re 1 µPa). Houser et al. (2013a) conducted a study to determine behavioral responses of captive California sea lions to MFA sonar at various received levels (125 to 185 dB re 1 µPa). They found younger animals (less than 2 years old) were more likely to respond than older animals and responses included increased respiration rate, increased time spent submerged, refusal to participate in a repetitive task, and hauling out. Most responses below 155 dB re 1 µPa were changes in respiration, while more severe responses ( i.e., refusing to participate, hauling out) began to occur over 170 dB re 1 µPa, and many of the most severe responses came from the young sea lions.

Responses Due to Impulsive Noise—

Impulsive signals have a rapid rise time and higher instantaneous peak pressure than other signal types, particularly at close range, which means they are more likely to cause startle or avoidance responses. At long distances, however, the rise time increases as the signal duration lengthens (similar to a “ringing” sound), making the impulsive signal more similar to a non-impulsive signal (Hastie et al., 2019; Martin et al., 2020). Behavioral responses from explosive sounds are likely to be similar to responses studied for other impulsive noise, such as those produced by air guns and impact pile driving. Data on behavioral responses to impulsive sound sources are limited across all marine mammal groups, with only a few studies available for mysticetes and odontocetes.

Mysticetes have varied responses to impulsive sound sources, including avoidance, aggressive directed movement towards the source, reduced surface intervals, altered swimming behavior, and changes in vocalization rates (Gordon et al., 2003; McCauley et al., 2000a; Richardson et al., 1985; Southall et al., 2007)

rine mammal groups, with only a few studies available for mysticetes and odontocetes.

Mysticetes have varied responses to impulsive sound sources, including avoidance, aggressive directed movement towards the source, reduced surface intervals, altered swimming behavior, and changes in vocalization rates (Gordon et al., 2003; McCauley et al., 2000a; Richardson et al., 1985; Southall et al., 2007). Studies have been conducted on many baleen whale species, including gray, humpback, blue, fin and bowhead whales; it is assumed that these responses are representative of all baleen whale species. The behavioral state of the whale seems to be an integral part of whether the animal responds and how they respond, as does the location and movement of the sound source, more than the received level of the sound.

If an individual is engaged in migratory behavior, it may be more likely to respond to impulsive noise, and some species may be more sensitive than others. Migrating gray whales showed avoidance responses to seismic vessels at received levels between 164 and 190 dB re 1 μPa (Malme et al., 1986, Malme et al., 1988). In one study, McCauley et al. (1998) found that migrating humpback whales in Australia showed avoidance behavior at ranges of 3.1-5 mi (5-8 km) from a seismic array during observational studies and controlled exposure experiments, and another study found humpback whales in Australia decreased their dive times and reduced their swimming speeds (Dunlop et al., 2015). However, when comparing received levels and behavioral responses between air gun ramp-up versus constant noise level of air guns, humpback whales did not change their dive behavior but did deviate from their predicted heading and decreased their swim speeds, deviating more during the constant noise source trials but reducing swim speeds more during ramp-up trials (Dunlop et al., 2016)

al., 2015). However, when comparing received levels and behavioral responses between air gun ramp-up versus constant noise level of air guns, humpback whales did not change their dive behavior but did deviate from their predicted heading and decreased their swim speeds, deviating more during the constant noise source trials but reducing swim speeds more during ramp-up trials (Dunlop et al., 2016). In both cases, there was no dose-response relationship with the received level of the air gun noise, and similar responses were observed in control trials without air guns (vessel movement remained constant across trials), so some responses may have been due to vessel presence and not received level from the air guns. Social interactions between males and mother-calf pairs were reduced in the presence of vessels towing seismic air gun arrays, regardless of whether the air guns were active or not; which indicates that it was likely the presence of vessels (rather than the impulsive noise generated from active air guns) that affected humpback whale behavior (Dunlop et al., 2020).

Proximity of the impulsive source is another important factor to consider when assessing the potential for behavioral responses in marine mammals. Dunlop et al. (2017) found that groups of humpback whales were more likely to avoid a smaller air gun array at closer proximity than a larger air gun array, despite the same received level, showing the difference in response between arrays has more to do with the combined effects of received level and source proximity. In this study, responses were varied and generally small, with short-term course deviations of about 1,640 ft (500 m). Studies on bowhead whales have shown they may be more sensitive than other species to impulsive noise, as individuals have shown clear changes in diving and breathing patterns up to 45.4 mi (73 km) from seismic vessels with received levels as low as 125 dB re 1 μPa (Malme et al. 1988). Richardson et al

was determined that baleen whale sightings were reduced by 88 percent during active and 87 percent during inactive phases of seismic surveys compared to regular surveys. These results seemed to occur regardless of geographic location of the survey; however, when only comparing active versus inactive periods of seismic surveys the geographic location did seem to affect the change in sighting rates.

Mysticetes seem to be the most behaviorally sensitive taxonomic group of marine mammals to impulsive sound sources, with possible avoidance responses occurring out to 18.6 mi (30 km) and vocal changes occurring in response to sounds over 62.1 mi (100 km) away. However, they are also the most studied taxonomic group, yielding a larger sample size and greater chance of finding behavioral responses to impulsive noise. Also, their responses appear to be behavior-dependent, with most avoidance responses occurring during migration behavior and little observed response during feeding behavior. These response patterns are likely to hold true for impulsive sources used by the Action Proponents; however, their impulsive sources

This text is long and has been trimmed here. Open the source document for the complete record.