[Federal Register Volume 88, Number 25 (Tuesday, February 7, 2023)]
[Proposed Rules]
[Pages 8146-8200]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-02242]



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Vol. 88

Tuesday,

No. 25

February 7, 2023

Part III





Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 218





Taking and Importing Marine Mammals; Taking Marine Mammals Incidental 
to Testing and Training Operations in the Eglin Gulf Test and Training 
Range; Proposed Rule

  Federal Register / Vol. 88, No. 25 / Tuesday, February 7, 2023 / 
Proposed Rules  

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 230127-0029]
RIN 0648-BL77


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to Testing and Training Operations in the Eglin Gulf Test 
and Training Range

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

ACTION: Proposed rule; request for comments and information.

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SUMMARY: NMFS has received a request from the U.S. Department of the 
Air Force (USAF) to take marine mammals incidental to testing and 
training military operations proposed to be conducted in the Eglin Gulf 
Test and Training Range (EGTTR) from 2023 to 2030 in the Gulf of 
Mexico. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is 
requesting comments on its proposal to issue regulations and subsequent 
Letter of Authorization (LOA) to the USAF to incidentally take marine 
mammals during the specified activities. NMFS will consider public 
comments prior to issuing any final rule and making final decisions on 
the issuance of the requested LOA. Agency responses to public comments 
will be summarized in the notice of the final decision in the final 
rule. The USAF's activities qualify as military readiness activities 
pursuant to the MMPA, as amended by the National Defense Authorization 
Act for Fiscal Year 2004 (2004 NDAA).

DATES: Comments and information must be received no later than March 9, 
2023.

ADDRESSES: Submit all electronic public comments via the Federal e-
Rulemaking Portal. Go to https://www.regulations.gov and enter NOAA-
NMFS-2021-0064 in the Search box. Click on the ``Comment'' icon, 
complete the required fields, and enter or attach your comments.
    Instructions: Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered by NMFS. All comments received are a part of the 
public record and will generally be posted for public viewing on 
www.regulations.gov without change. All personal identifying 
information (e.g., name, address), confidential business information, 
or otherwise sensitive information submitted voluntarily by the sender 
will be publicly accessible. NMFS will accept anonymous comments (enter 
``N/A'' in the required fields if you wish to remain anonymous). 
Attachments to electronic comments will be accepted in Microsoft Word, 
Excel, or Adobe PDF file formats only.
    A copy of the USAF's application and other supporting documents and 
documents cited herein may be obtained online at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-air-force-eglin-gulf-testing-and-training. In case of problems accessing 
these documents, please use the contact listed here (see FOR FURTHER 
INFORMATION CONTACT).

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

SUPPLEMENTARY INFORMATION: 

Purpose of Regulatory Action

    These proposed regulations, issued under the authority of the MMPA 
(16 U.S.C. 1361 et seq.), would provide the framework for authorizing 
the take of marine mammals incidental to the USAF's training and 
testing activities (which qualify as military readiness activities) 
from air-to-surface operations that involve firing live or inert 
munitions, including missiles, bombs, and gun ammunition, from aircraft 
at various types of targets on the water surface. Live munitions used 
in the EGTTR are set to detonate either in the air a few feet above the 
water, instantaneously upon contact with the water or target, or 
approximately 5 to 10 feet (ft) (1.5 to 3 meters (m)) below the water 
surface. There would also be training exercises for Navy divers that 
require the placement of small explosive charges by hand to disable 
live mines.
    Eglin Air Force Base (AFB) would conduct operations in the existing 
Live Impact Area (LIA). In addition, the USAF is also proposing to 
create and use a new, separate LIA within the EGTTR that would be used 
for live missions in addition to the existing LIA. Referred to as the 
East LIA, it is located approximately 40 nautical miles (nmi)/(74 
kilometers (km)) southeast of the existing LIA. (See Figure 1).
    NMFS received an application from the USAF requesting 7-year 
regulations and an authorization to incidentally take individuals of 
multiple species of marine mammals (``USAF's rulemaking/LOA 
application'' or ``USAF's application''). Take is anticipated to occur 
by Level A and Level B harassment incidental to the USAF's training and 
testing activities, with no serious injury or mortality expected or 
proposed for authorization.

Background

    The MMPA prohibits the take of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA direct the 
Secretary of Commerce (as delegated to NMFS) to allow, upon request, 
the incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review and the opportunity to submit 
comments.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stocks and will not have an unmitigable adverse impact on the 
availability of the species or stocks for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other means of effecting the least practicable adverse 
impact on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in this rule as 
``mitigation measures''). NMFS also must prescribe the requirements 
pertaining to the monitoring and reporting of such takings. The MMPA 
defines ``take'' to mean to harass, hunt, capture, or kill, or attempt 
to harass, hunt, capture, or kill any marine mammal. The Preliminary 
Analysis and Negligible Impact Determination section below discusses 
the definition of ``negligible impact.''
    The NDAA for Fiscal Year 2004 (2004 NDAA) (Pub. L. 108-136) amended 
section 101(a)(5) of the MMPA to remove the ``small numbers'' and 
``specified geographical region'' provisions indicated above and 
amended the definition of ``harassment'' as applied to a ``military 
readiness activity.'' The definition of harassment for military 
readiness activities (section 3(18)(B) of the MMPA) is: (i) Any act 
that injures or has the significant potential to injure a marine mammal 
or marine mammal stock in the wild (Level A Harassment); or (ii) Any 
act that disturbs or is likely to disturb a marine mammal or marine 
mammal stock in the wild by causing disruption of natural

[[Page 8147]]

behavioral patterns, including, but not limited to, migration, 
surfacing, nursing, breeding, feeding, or sheltering, to a point where 
such behavioral patterns are abandoned or significantly altered (Level 
B harassment). In addition, the 2004 NDAA amended the MMPA as it 
relates to military readiness activities such that the least 
practicable adverse impact analysis shall include consideration of 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    More recently, section 316 of the NDAA for Fiscal Year 2019 (2019 
NDAA) (Pub. L. 115-232), signed on August 13, 2018, amended the MMPA to 
allow incidental take rules for military readiness activities under 
section 101(a)(5)(A) to be issued for up to 7 years. Prior to this 
amendment, all incidental take rules under section 101(a)(5)(A) were 
limited to 5 years.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must evaluate our USAF's proposed activities and alternatives with 
respect to potential impacts on the human environment. Accordingly, 
NMFS plans to adopt the Eglin Gulf Test and Training Range 
Environmental Assessment (2022 REA) (USAF 2022), provided our 
independent evaluation of the document finds that it includes adequate 
information analyzing the effects on the human environment of issuing 
regulations and LOAs under the MMPA. NMFS is a cooperating agency on 
the 2022 REA and has worked with the USAF developing the document. The 
draft 2022 REA was made available for public comment on December 13, 
2022 through January 28, 2023. We will review all comments submitted in 
response to the request for comments on the 2022 REA and in response to 
the request for comments on this proposed rule prior to concluding our 
NEPA process or making a final decision on this proposed rule for the 
issuance of regulations under the MMPA and any subsequent issuance of a 
Letter of Authorization (LOA) to the USAF to incidentally take marine 
mammals during the specified activities.

Summary of Request

    On January 18, 2022, NMFS received an application from the USAF for 
authorization to take marine mammals by Level A and Level B harassment 
incidental to training and testing activities (categorized as military 
readiness activities) in the EGTTR for a period of 7 years. On June 17, 
2022 NMFS received an adequate and complete application for missions 
that would include air-to-surface operations that involve firing live 
or inert munitions, including missiles, bombs, and gun ammunition from 
aircraft at targets on the water surface. The types of targets used 
vary by mission and primarily include stationary, remotely controlled, 
and towed boats, inflatable targets, and marker flares. Live munitions 
used in the EGTTR are set to detonate either in the air a few feet 
above the water surface (airburst detonation), instantaneously upon 
contact with the water or target (surface detonation), or approximately 
5 to 10 feet (1.5 to 3 m) below the water surface (subsurface 
detonation). On July 17, 2022, we published a notice of receipt (NOR) 
of application in the Federal Register (87 FR 42711), requesting 
comments and information related to the USAF's request. The public 
comment period was open for 30 days. We reviewed and considered all 
comments and information received on the NOR in development of this 
proposed rule.
    On February 8, 2018, NMFS promulgated a rulemaking and issued an 
LOA for takes of marine mammals incidental to Eglin AFB's training and 
testing operations in the EGTTR (83 FR 5545). Current EGTTR operations 
are authorized under the 2018 EGTTR LOA which will expire on February 
12, 2023. Under this proposed rulemaking action, the EGTTR would 
continue to be used during the next mission period based on the 
maritime training and testing requirements of the various military 
units that use the EGTTR. The next mission period would span 7 years, 
from 2023 to 2030. Most operations during this period would be a 
continuation of the same operations conducted by the same military 
units during the previous mission period. There would, however, be an 
increase in the annual quantities of all general categories of 
munitions (bombs, missiles, and gun ammunition) under the USAF's 
proposed activities, except for live gun ammunition, which is proposed 
to be used less over the next mission period. The highest net explosive 
weight (NEW) of the munitions under the USAF's proposed activities 
would be 945 pounds (lb) (430 kilograms (kg), which was also the 
highest NEW for the previous mission period. Live missions proposed for 
the 2023-2030 period would be conducted in the existing Live Impact 
Area (LIA) within the EGTTR. Certain missions may also be conducted in 
the proposed East LIA, which would be a new, separate area within the 
EGTTR where live munitions would be used. The USAF's rulemaking/LOA 
application reflects the most up-to-date compilation of training and 
testing activities deemed necessary to accomplish military readiness 
requirements. EGTTR training and testing operations are critical for 
achieving military readiness and the overall goals of the National 
Defense Strategy. The regulations proposed in this action, if issued, 
would be effective for seven years, beginning from the date of 
issuance.

Description of the Proposed Activity

    The USAF requests authorization to take marine mammals incidental 
to conducting training and testing activities. The USAF has determined 
that acoustic and explosives stressors are most likely to result in 
impacts on marine mammals that could qualify as take under the MMPA, 
and NMFS concurs with this determination. Eglin AFB proposes to conduct 
military aircraft missions within the EGTTR that involve the employment 
of multiple types of live (explosive) and inert (non-explosive) 
munitions (i.e., missiles, bombs, and gun ammunition) against various 
surface targets. Munitions may be delivered by multiple types of 
aircraft including, but not limited to, fighter jets, bombers, and 
gunships.
    Detailed descriptions of these activities are described in the 
Eglin Gulf Test and Training Range (EGTTR) Range Environmental 
Assessment (REA) (USAF 2022), currently under preparation as well as 
the USAF's rulemaking/LOA application. (https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-air-force-eglin-gulf-testing-and-training). A summary of the proposed activities and are presented 
below.

Dates and Duration

    The specified activities would occur at any time during the 7-year 
period of validity of the regulations. The proposed amount of training 
and testing activities are described in the Detailed Description of the 
Specified Activities section.

Geographical Region

    The Eglin Military Complex encompasses approximately 724 square 
miles (1,825 km\2\ of land in the Florida Panhandle and consists of the 
Eglin Reservation in Santa Rosa, Okaloosa, and Walton Counties, and 
property on Santa Rosa Island and Cape San Blas. The EGTTR is the 
airspace controlled by Eglin AFB over the Gulf of Mexico, beginning 3 
nautical miles (nmi) (5.56

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km) from shore, and the underlying Gulf of Mexico waters. The EGTTR 
extends southward and westward off the coast of Florida and encompasses 
approximately 102,000 nmi (349,850 km\2\). It is subdivided into blocks 
of airspace that consist of Warning Areas W-155, W-151, W-470, W-168, 
and W-174 and Eglin Water Test Areas 1 through 6 (Figure 1). Most of 
the blocks are further subdivided into smaller airspace units for 
scheduling purposes (for example, W-151A, B, C, and D). Although Eglin 
AFB may use any portion of the EGTTR, the majority of training and 
testing operations proposed for the 2023-2030 mission period would 
occur in Warning Area W-151. The nearshore boundary of W-151 parallels 
much of the coastline of the Florida Panhandle and extends horizontally 
from 3 nmi (5.56 km) offshore to approximately 85 to 100 nmi (158 to185 
km) to offshore, depending on the specific portion of its outer 
boundary. W-151 encompasses approximately 10,247 nmi\2\ (35146 km\2\) 
and includes water depths that range from approximately 5 to 720 m. The 
existing LIA, which is the portion of the EGTTR where the use of live 
munitions is currently authorized, lies mostly within W-151. The 
existing LIA encompasses approximately 940 nmi\2\ (3,224 km\2\ and 
includes water depths that range from approximately 30 to 145 m (Figure 
2). This is where live munitions within the EGTTR are currently used in 
the existing LOA (83 FR 5545; February 8, 2018) and where the Gulf 
Range Armament Test Vessel (GRATV) is anchored. The GRATV remains 
anchored at a specific location during a given mission; however, it is 
mobile and relocated within the LIA based on mission needs.
    The USAF's proposed activities provide for the creation of a new, 
separate area within the EGTTR that would be used for live missions in 
addition to the existing LIA. This area, herein referred to as the East 
LIA, would be located approximately 40 NM offshore of Eglin AFB 
property on Cape San Blas. Cape San Blas is located on St. Joseph 
Peninsula in Gulf County, Florida, approximately 90 mi (144 km) 
southeast of the Eglin Reservation. Eglin AFB facilities on Cape San 
Blas remotely support EGTTR operations via radar tracking, telemetry, 
and other functions. The proposed East LIA would be circular-shaped and 
have a radius of approximately 10 nmi (18.5 km) and a total area of 
approximately 314 NM \2\. Water depths range from approximately 35 to 
95 m. The general location of the proposed East LIA is shown in Figure 
2. Establishment of the East LIA would allow Eglin AFB to maximize the 
flight range for large-footprint weapons and minimize the distance, 
time, and cost of deploying support vessels and targets. Based on these 
factors, the East LIA would allow testing of weapon systems and flight 
profiles that cannot be conducted within the constraints of the 
existing LIA.
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Detailed Description of the Specified Activities

    This section provides descriptions of each military user group's 
proposed EGTTR operations, as well as information regarding munitions 
proposed to be used during the operations. This information includes 
munition type, category, net explosive weight (NEW), detonation 
scenario, and annual quantity proposed to be expended in the EGTTR. NEW 
applies only to live munitions and is the total mass of the explosive 
substances in a given munition, without packaging, casings, bullets, or 
other non-explosive components of the munition. Note that for some 
munitions the warhead is removed and replaced with a telemetry package 
that tracks the munition's path and/or Flight Termination System (FTS) 
that ends the flight of the munition in a controlled manner. These 
munitions have been categorized as live munitions with NEWs that range 
from 0.30 to 0.70

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lb (0.13 to 0.31 kg) While certain munitions with only FTS may be 
considered inert due to negligible NEW, those contained here are 
considered to be live with small amounts of NEW. The detonation 
scenario applies only to live munitions which are set to detonate in 
one of three ways: (1) in the air a few feet above the water surface, 
referred to as airburst or height of burst (HOB); (2) instantaneously 
upon contact with the water or target on the water surface; or (3) 
after a slight delay, up to 10 milliseconds, after impact, which would 
correspond to a subsurface detonation at a water depth of approximately 
5 to 10 ft (1.5 to 3 m). Estimated take is only modeled for scenarios 
(2) and (3). The proposed annual expenditures of munitions are the 
quantities determined necessary to meet the mission requirements of the 
user groups.
    Live missions proposed for the 2023-2030 period would be conducted 
in the existing LIA and potentially in the proposed East LIA, depending 
on the mission type and objectives. Live missions that involve only 
airburst or aerial target detonations would continue to be conducted in 
or outside the LIA in any portion of the EGTTR; such detonations have 
no appreciable effect on marine mammals because there is negligible 
transmission of pressure or acoustic energy across the air-water 
interface. Use of inert munitions and live air-to-surface gunnery 
operations would also continue to occur in or outside the LIA, subject 
to proposed mitigation and monitoring measures.
    Eglin AFB proposes the following actions in the EGTTR which would 
be conducted in the existing LIA and potentially in the proposed East 
LIA, depending on the mission type and objectives:
    (1) 53rd Weapons Evaluation Group missions that involve air-to-
ground Weapons System Evaluation Program (WSEP) known as Combat Hammer 
which tests various types of munitions against small target boats and 
air-to-air missile testing known as Combat Archer;
    (2) Continuation of the Air Force Special Operations Command 
(AFSOC) training missions in the EGTTR primarily involving air-to-
surface gunnery, bomb, and missile exercises including AC-130 gunnery 
training, CV-22 training, and bomb and missile training;
    (3) 96th Operations Group missions including AC-130 gunnery testing 
against floating marker targets on the water surface, MQ-9 air-to-
surface testing, and 780th Test Squadron Precision Strike Weapons 
testing including air-launched cruise missile tests, air-to-air missile 
tests, Longbow and Joint Air-to-Ground Missile (JAGM) testing; Spike 
Non-Line-of-Sight (NLOS) air-to-surface missile testing, Patriot 
missile testing, Hypersonic Weapon Testing, sink at-sea live-fire 
training exercises (SINKEX), and testing using live and inert munitions 
against targets on the water surface; and
    (4) Naval School Explosive Ordnance Disposal (NAVSCOLEOD) training 
missions that involve students diving and placing small explosive 
charges adjacent to inert mines.
53rd Weapons Evaluation Group
    The 53rd Weapons Evaluation Group (53 WEG) conducts the USAF's air-
to-ground Weapons System Evaluation Program (WSEP). The Combat Hammer 
program involves testing various types of live and inert munitions 
against small target boats. This testing is conducted to develop 
tactics, techniques, and procedures (TTP) to be used by USAF aircraft 
to counter small, maneuvering, hostile vessels. Combat Hammer missions 
proposed in the EGTTR for the 2023-2030 period would involve the use of 
several types of aircraft, including F-15, F-16, F-18, F-22, F-35, and 
A-10 fighter aircraft, AC-130 gunships, B-1, B-2, and B-52 bomber 
aircraft, and MQ-1 and MQ-9 drone aircraft. USAF, Air National Guard, 
and U.S. Navy units would support these missions. Live munitions would 
be deployed against static (anchored), remotely controlled, and towed 
targets. Static and remotely controlled targets would consist of 
stripped boat hulls with simulated systems and, in some cases, heat 
sources. Various types of live and inert munitions are used during 
Combat Hammer missions in the EGTTR, including missiles, bombs, and gun 
ammunition. Table 1 presents information on the munitions proposed for 
Combat Hammer missions in the EGTTR during the 2023-2030 period.

                    Table 1--Proposed Munitions for WSEP Combat Hammer Missions in the EGTTR
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                                                         Net explosive        Destination
              Type                      Category        weight (lb)/(kg)        scenario        Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
    AGR-20......................  Rocket.............          9.1 (4.1)  Surface............                 12
    AGM-158D JASSM XR...........  Missile............     240.26 (108.9)  Surface............                  4
    AGM-158B JASSM ER...........  Missile............     240.26 (108.9)  Surface............                  3
    AGM-158A JASSM..............  Missile............     240.26 (108.9)  Surface............                  3
    AGM-65D.....................  Missile............           150 (68)  Surface............                  5
    AGM-65G2....................  Missile............         145 (65.7)  Surface............                  5
    AGM-65H2....................  Missile............           150 (68)  Surface............                  5
    AGM-65K2....................  Missile............         145 (65.7)  Surface............                  4
    AGM-65L.....................  Missile............           150 (68)  Surface............                  5
    AGM-114 N-6D with TM........  Missile............        29.1 (13.2)  Surface............                  4
    AGM-114 N-4D with TM........  Missile............       29.94 (13.6)  Surface............                  4
    AGM-114 R2 with TM (R10)....  Missile............       27.41 (12.4)  Surface............                  4
    AGM-114 R-9E with TM (R11)..  Missile............       27.38 (12.4)  Surface............                  4
    AGM-114Q with TM............  Missile............        20.16 (9.1)  Surface............                  4
    CBU-105D....................  Bomb...............       108.6 (49.5)  HOB................                  8
    GBU-53/B (GTV)..............  Bomb...............       0.34(0.1)\a\  HOB/Surface........                  8
    GBU-39 SDB (GTV)............  Bomb...............       0.39(0.1)\a\  Surface............                  4
    AGM-88C w/FTS...............  Missile............     0.70 (0.31)\a\  Surface............                  2
    AGM-88B w/FTS...............  Missile............     0.70 (0.31)\a\  Surface............                  2
    AGM-88F w/FTS...............  Missile............      0.70(0.31)\a\  Surface............                  2
    AGM-88G w/FTS...............  Missile............      0.70(0.31)\a\  Surface............                  2
    AGM-179 JAGM................  Missile............        27.47(12.5)  Surface............                  4
    GBU-69......................  Bomb...............         6.88 (3.1)  Surface............                  2
    GBU-70......................  Bomb...............         6.88 (3.1)  Surface............                  4

[[Page 8152]]

 
    AGM-176.....................  Missile............         8.14 (3.7)  Surface............                  4
    GBU-54 KMU-572C/B...........  Bomb...............         193 (87.5)  Surface............                  4
    GBU-54 KMU-572B/B...........  Bomb...............                193  Surface............                  4
    PGU-43 (105 mm).............  Gun Ammunition.....                4.7  Surface............                100
Inert Munitions:
    ADM-160B MALD...............  Missile............                N/A  N/A................                  4
    ADM-160C MALD-J.............  Missile............                N/A  N/A................                  4
    ADM-160C-1 MALD-J...........  Missile............                N/A  N/A................                  4
    ADM-160D MALD-J.............  Missile............                N/A  N/A................                  4
    GBU-10......................  Bomb...............                N/A  N/A................                  8
    GBU-12......................  Bomb...............                N/A  N/A................                 32
    GBU-49......................  Bomb...............                N/A  N/A................                 16
    GBU-24/B (84)...............  Bomb...............                N/A  N/A................                 16
    GBU-24A/B (109).............  Bomb...............                N/A  N/A................                  2
    GBU-31B(v)1.................  Bomb...............                N/A  N/A................                 16
    GBU-31C(v)1.................  Bomb...............                N/A  N/A................                 16
    GBU-31B(v)3.................  Bomb...............                N/A  N/A................                  2
    GBU-31C(v)3.................  Bomb...............                N/A  N/A................                  2
    GBU-32C.....................  Bomb...............                N/A  N/A................                  8
    GBU-38B.....................  Bomb...............                N/A  N/A................                  4
    GBU-38C w/BDU-50 (No TM)....  Bomb...............                N/A  N/A................                  4
    GBU-38C.....................  Bomb...............                N/A  N/A................                 10
    GBU-54 KMU-572C/B...........  Bomb...............                N/A  N/A................                  4
    GBU-54 KMU-572B/B...........  Bomb...............                N/A  N/A................                  4
    GBU-69......................  Bomb...............                N/A  N/A................                  2
    BDU-56A/B...................  Bomb...............                N/A  N/A................                  4
    PGU-27 (20 mm)..............  Gun Ammunition.....        0.09 (0.04)  N/A................             16,000
    PGU-15 (30 mm)..............  Gun Ammunition.....                N/A  N/A................             16,000
    PGU-25 (25 mm)..............  Gun Ammunition.....                N/A  N/A................             16,000
    ALE-50......................  Decoy System.......                N/A  N/A................                  6
----------------------------------------------------------------------------------------------------------------
\a\ Warhead replaced by FTS/TM. Identified NEW is for the FTS.
 ADM = American Decoy Missile; AGM = Air-to-Ground Missile; ALE = Ammunition Loading Equipment; BDU = Bomb Dummy
  Unit; CBU = Cluster Bomb Unit; EGTTR = Eglin Gulf Test and Training Range; ER = Extended Range; FTS = Flight
  Termination System; GBU = Guided Bomb Unit; GTV = Guided Test Vehicle; HOB = height of burst; JAGM = Joint Air-
  to-Ground Missile; JASSM = Joint Air-to-Surface Standoff Missile; lb = pound(s); MALD = Miniature Air-Launched
  Decoy; mm = millimeter(s); N/A = not applicable; PGU = Projectile Gun Unit; SDB = Small-Diameter Bomb, TM =
  telemetry; WSEP = Weapons System Evaluation Program.

    The Combat Archer program involves live air-to-air missile testing 
in the EGTTR. Combat Archer missions also include firing inert gun 
ammunition and releasing flares and chaff from aircraft. Air-to-air 
missile testing during these missions specifically involves firing live 
AIM-9 Sidewinder and AIM-120 Advanced Medium-Range Air-to-Air Missiles 
(AMRAAMs) at BOM-167 Subscale Aerial Targets and QF-16 Full-Scale 
Aerial Targets to evaluate the effectiveness of missile delivery 
techniques. Combat Archer missions involve the use of several types of 
fighter aircraft, including the F-15, F-16, F-18, F-22, F-35, and A-10. 
Table 2 presents information on the munitions proposed to be used 
during Combat Archer missions in the EGTTR.

                       Table 2--Proposed Munitions for Combat Archer Missions in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive
              Type                      Category       weight  (lb)/(kg)  Detonation scenario   Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
    AIM-120D....................  Missile............      113.05 (51.3)  HOB................                 24
    AIM-120C7...................  Missile............      113.05 (51.3)  HOB................                 10
    AIM-120C5/6.................  Missile............      113.05 (51.3)  HOB................                  8
    AIM-120C3...................  Missile............      102.65 (46.5)  HOB................                 14
    AIM-120C3...................  Missile............      117.94 (63.5)  HOB/Surface........                  4
    AIM-120B....................  Missile............      102.65 (46.5)  HOB................                 18
    AIM-9X Blk I................  Missile............       60.25 (27.3)  HOB................                  7
    AIM-9X Blk I................  Missile............        67.9 (30.8)  HOB/Surface........                 10
    AIM-9X Blk II...............  Missile............       60.25 (27.3)  HOB................                 24
    AIM-9M-9....................  Missile............       60.55 (27.3)  HOB................                 90
Inert Munitions:
    AIM-260A JATM...............  Missile............                N/A  N/A................                  4
    PGU-27 (20 mm)..............  Gun Ammunition.....                N/A  N/A................             80,000
    PGU-23 (25 mm)..............  Gun Ammunition.....                N/A  N/A................              6,000
    MJU-7A/B Flare..............  Flare..............                N/A  N/A................              1,800
    R-188 Chaff.................  Chaff..............                N/A  N/A................              6,000

[[Page 8153]]

 
    R-196 (T-1) Chaff...........  Chaff..............                N/A  N/A................              1,500
----------------------------------------------------------------------------------------------------------------
AIM = Air Intercept Missile; EGTTR = Eglin Gulf Test and Training Range; HOB = height of burst; JATM = Joint
  Advanced Tactical Missile; lb = pound(s); MJU = Mobile Jettison Unit; mm = millimeter(s); N/A = not
  applicable; PGU = Projectile Gun Unit; WSEP = Weapons System Evaluation Program.

Air Force Special Operations Command Training
    The Air Force Special Operations Command (AFSOC) proposes to 
continue conducting training missions during the 2023-2030 period. 
These missions primarily involve air-to-surface gunnery, bomb, and 
missile exercises. Gunnery training in the EGTTR involves firing live 
rounds from AC-130 gunships at targets on the water surface. Gun 
ammunition used for this training primarily includes 30-millimeter (mm) 
High Explosive (HE) and 105 mm HE rounds. A standard 105 mm HE round 
has a NEW of 4.7 lb. The Training Round (TR) variant of the 105 mm HE 
round, which has a NEW of 0.35 lb, is used by AFSOC for nighttime 
missions. This TR was developed to have less explosive material to 
minimize potential impacts to protected marine species, which could not 
be adequately surveyed at night by earlier aircraft instrumentation. 
Since the development of the 105 mm HE TR, AC-130s have been equipped 
with low-light electro-optical and infrared sensor systems that provide 
excellent night vision. Targets used for AC-130 gunnery training 
include Mark (Mk)-25 marine markers and inflatable targets. During each 
gunnery training mission, gun firing can last up to 90 minutes but 
typically lasts approximately 30 minutes. Live firing is continuous, 
with pauses usually lasting well under 1 minute and rarely up to 5 
minutes. Table 3 presents information on the rounds proposed for AC-130 
gunnery training by AFSOC.

                        Table 3--Proposed Rounds for AC-130 Gunnery Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                Net explosive       Detonation       Number of      Rounds per        Annual
            Type              weight  (lb)/(kg)      scenario        missions         mission        quantity
----------------------------------------------------------------------------------------------------------------
Daytime Missions:
    105 mm HE (FU)..........          4.7 (2.1)  Surface........              25              30             750
    30 mm HE................         0.1 (0.04)                                              500          12,500
Nighttime Missions:
    105 mm HE (TR)..........          0.35 (0.2  Surface........              45              30           1,350
    30 mm HE................         0.1 (0.04)                                              500          22,500
                             -------------------                 -----------------------------------------------
        Total...............  .................  ...............              70  ..............          37,100
----------------------------------------------------------------------------------------------------------------
EGTTR = Eglin Gulf Test and Training Range; FU = Full Up; HE = High Explosive; mm = millimeter(s); lb =
  pound(s); TR = Training Round.

    The 8th Special Operations Squadron (8 SOS) under AFSOC conducts 
training in the EGTTR using the tiltrotor CV-22 Osprey. This training 
involves firing .50 caliber rounds from CV-22s at floating marker 
targets on the water surface. The .50 caliber rounds do not contain 
explosive material and, therefore, do not detonate. Flight procedures 
for CV-22 training are similar to those described for AC-130 gunnery 
training, except that CV-22 aircraft typically operate at much lower 
altitudes (100 to 1,000 feet (30.48 to 304.8 m) (AGL) than AC-130 
gunships (6,000 to 20,000 feet (1,828 to6,96 m) AGL). Like AC-130 
gunships, CV-22s are equipped with highly sophisticated electro-optical 
and infrared sensor systems that allow advanced detection capability 
during day and night. Table 4 presents information on the rounds 
proposed for CV-22 training missions.

                            Table 4--Proposed Rounds for CV-22 Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                Net explosive       Detonation       Number of      Rounds per        Annual
            Type                 weight  (lb)        scenario        missions         mission        quantity
----------------------------------------------------------------------------------------------------------------
Daytime Missions:
    .50 Caliber.............                N/A  Surface........              25             600          15,000
Nighttime Missions:
    .50 Caliber.............                N/A  Surface........              25             600          15,000
                                                -----------------                -------------------------------
        Total...............  .................  ...............  ..............              50          30,000
----------------------------------------------------------------------------------------------------------------

    In addition to AC-130 gunnery and CV-22 training, AFSOC also 
conducts other air-to-surface training in the EGTTR using various types 
of bombs and missiles as shown in Table 5. This training is conducted 
primarily to develop TTPs and train strike aircraft to counter small 
moving boats. Munitions used for this training primarily include live 
AGM-176 Griffin missiles, live AGM-114 Hellfire missiles, and various 
types of live and inert bombs. These

[[Page 8154]]

munitions are launched from various types of aircraft against small 
target boats, and they either detonate on impact with the target or at 
a programmed HOB.

                  Table 5--Proposed Munitions for AFSOC Bomb and Missile Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                    Net explosive weight         Detonation
             Type                  Category               (lb)(kg)                scenario      Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
    AGM-176 Griffin..........  Missile........                    4.58 (2.1)  HOB............                100
    AGM-114R9E/R2 Hellfire...  Missile........                   20.0 (9.07)  HOB............                 70
    2.75-inch Rocket           Rocket.........                     2.3 (1.0)  Surface........                400
     (including APKWS).
    GBU-12...................  Bomb...........    198.0 (89.8)/298.0 (135.1)  Surface........                 30
    Mk-81 (GP 250 lb)........  Bomb...........                  151.0 (98.4)  Surface........                 30
    GBU-39 (SDB I)...........  Bomb...........                   37.0 (16.7)  HOB............                 30
    GBU-69...................  Bomb...........                   36.0 (16.3)  HOB............                 40
Inert Munitions:
    .50 caliber..............  Gun Ammunition.                           N/A  N/A............             30,000
    GBU-12...................  Bomb...........                           N/A  N/A............                 30
    MkK-81 (GP 250 lb).......  Bomb...........                           N/A  N/A............                 30
    BDU-50...................  Bomb...........                           N/A  N/A............                 30
    BDU-33...................  Bomb...........                           N/A  N/A............                 50
----------------------------------------------------------------------------------------------------------------
AFSOC = Air Force Special Operations Command; AGM = Air-to-Ground Missile; APKWS = Advanced Precision Kill
  Weapon System; BDU = Bomb Dummy Unit; EGTTR = Eglin Gulf Test and Training Range; GBU = Guided Bomb Unit; GP =
  General Purpose; HOB = height of burst; lb = pound(s); Mk = Mark; N/A = not applicable; SDB = Small-Diameter
  Bomb.

96th Operations Group
    Three units under the 96th Operations Group (96 OG) propose to 
conduct missions in the EGTTR during the 2023-2030 period: the 417th 
Flight Test Squadron (417 FLTS), the 96th Operational Support Squadron 
(96 OSS), and the 780th Test Squadron (780 TS).
    The 417 FLTS proposes to continue conducting AC-130 testing in the 
EGTTR to evaluate the capabilities of the Precision Strike Package 
(PSP), Stand Off Precision Guided Munitions (SOPGM), and other systems 
on AC-13O aircraft. AC-130 gunnery testing is generally similar to 
activities previously described for AFSOC AC-130 gunnery training.
    Table 6 presents information on the munitions proposed for AC-130 
testing in the EGTTR during the 2023-2030 mission period.

                        Table 6--Proposed Rounds for AC-130 Gunnery Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive
              Type                      Category       weight  (lb)/(kg)  Detonation scenario   Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
    AGM-176 Griffin.............  Missile............         4.58 (2.1)  Surface............                 10
    AGM-114 Hellfire............  Missile............         20.0 (9.1)  Surface............                 10
    GBU-39 (SDB I)..............  Bomb...............        37.0 (16.8)  Surface............                  6
    GBU-39 (LSDB)...............  Bomb...............        37.0 (16.8)  Surface............                 10
    105 mm HE (FU)..............  Gun Ammunition.....          4.7 (2.1)  Surface............                 60
    105 mm HE (TR)..............  Gun Ammunition.....         0.35 (0.2)  Surface............                 60
    30 mm HE....................  Gun Ammunition.....          0.1 (0.1)  Surface............                 99
----------------------------------------------------------------------------------------------------------------
AGM = Air-to-Ground Missile; EGTTR = Eglin Gulf Test and Training Range; FU = Full Up; GBU = Guided Bomb Unit;
  HE = High Explosive; lb = pound(s); mm = millimeter(s); LSDB = Laser Small-Diameter Bomb; SDB = Small-Diameter
  Bomb; TR = Training Round.

    The 96 OSS proposes to conduct air-to-surface testing in the EGTTR 
using assorted live missiles and live and inert precision-guided bombs 
to support testing requirements of the MQ-9 Reaper unmanned aerial 
vehicle (UAV) program. The proposed munitions would be tested for MQ-9 
integration and would include captive carry and munitions employment 
tests. During munition employment tests, the proposed munitions would 
be launched from MQ-9 aircraft at various types of static and moving 
targets on the water surface. Table 7 presents information on the 
munitions proposed by the 96 OSS for MQ-9 testing in the EGTTR.

                            Table 7--Proposed Munitions for MQ-9 Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive
              Type                      Category       weight  (lb)/(kg)  Detonation scenario   Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
    AGM-114R Hellfire...........  Missile............         20.0 (9.1)  Surface............                 36
    AIM-9X......................  Missile............          7.9 (3.6)  HOB................                  1

[[Page 8155]]

 
    GBU-39B/B LSDB..............  Bomb...............        37.0 (16.8)  Surface............                  2
Inert Munitions:
    GBU-39B/B LSDB..............  Bomb...............                N/A  N/A................                  2
    GBU-49......................  Bomb...............                N/A  N/A................                 10
    GBU-48......................  Bomb...............                N/A  N/A................                  1
----------------------------------------------------------------------------------------------------------------
AGM = Air-to-Ground Missile; AIM = Air Intercept Missile; EGTTR = Eglin Gulf Test and Training Range; GBU =
  Guided Bomb Unit; lb = pound(s); LSDB = Laser Small-Diameter Bomb.

    The 780 TS, the Air Force Life Cycle Management Center, and the 
U.S. Navy jointly conduct Precision Strike Weapons (PSW) test missions 
in the EGTTR. These missions use the AGM-158 JASSM and GBU-39 SDB 
precision-guided bomb. The JASSM is an air-launched cruise missile with 
a range of more than 200 nmi (370 km). During test missions, the JASSM 
would be launched from aircraft more than 200 nmi (370 km) from the 
target location at altitudes greater than 25,000 ft (7,620 m) km above 
ground level (AGL). The JASSM would cruise at altitudes greater than 
12,000 ft (3,657 m) AGL for most of the flight profile until its 
terminal descent toward the target. The GBU-39 SDB is a precision-
guided glide bomb with a range of more than 50 nmi (92.6 km). This bomb 
would be launched from aircraft more than 50 nmi (92.6 km) from the 
target location at altitudes greater than 5,000 ft (1,524 m) AGL. The 
bomb would travel via a non-powered glide to the intended target. 
Instrumentation in the bomb self-controls the bomb's flight path. Live 
JASSMs would detonate at a HOB of approximately 5 ft (0.30 m); however, 
these detonations are assumed to occur at the surface for the impact 
analysis. The SDBs would detonate either at a HOB of approximately 7 to 
14 ft (2.1 to 4.2 m) or upon impact with the target (surface). For 
simultaneous SDB launches, two SDBs would be launched from the same 
aircraft at approximately the same time to strike the same target. The 
SDBs would strike the target within approximately 5 seconds or less of 
each other. Such detonations would be considered a single event, with 
the associated NEW being doubled for a conservative impact analysis.
    Two types of targets are typically used for PSW tests: Container 
Express (CONEX) targets and hopper barge targets. CONEX targets 
typically consist of up to five CONEX containers strapped, braced, and 
welded together to form a single structure. A hopper barge is a common 
type of barge that cannot move itself; a typical hopper barge measures 
approximately 30 ft (9.1 m) by 12 ft (3.6 m) by 125 ft (38.1 m).
    Other SDB tests in the EGTTR during the 2023-2030 mission period 
may include operational testing of the GBU-53 (SDB II). These tests may 
involve live and inert testing of the munition against target boats.
    Table 8 presents information on the munitions proposed for PSW 
missions in the EGTTR during the 2023-2030 period.

                        Table 8--Proposed Munitions for Precision Strike Weapon Missions
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive
              Type                      Category       weight  (lb)/(kg)  Detonation scenario   Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
    AGM-158 (JASSM).............  Missile............     240.26 (108.9)  Surface............                  2
    GBU-39 (SDB I)..............  Bomb...............        37.0 (16.8)  HOB/Surface........                  2
    GBU-39 (SDB I) Simultaneous   Bomb...............       74.0 (33.35)  HOB/Surface........                  2
     Launch\a\.
    GBU-53 (SDB II).............  Bomb...............       22.84 (10.4)  HOB/Surface........                  2
Inert Munitions:
    AGM-158 (JASSM).............  Missile............                N/A  N/A................                  4
    GBU-39 (SDB I)..............  Bomb...............                N/A  N/A................                  4
    GBU-39 (SDB I) Simultaneous   Bomb...............                N/A  N/A................                  4
     Launch.
    GBU-53 (SDB II).............  Bomb...............                N/A  N/A................                  1
----------------------------------------------------------------------------------------------------------------
\a\ NEW is doubled for simultaneous launch.
AGM = Air-to-Ground Missile; EGTTR = Eglin Gulf Test and Training Range; GBU = Guided Bomb Unit; HOB = height of
  burst; JASSM = Joint Air-to-Surface Standoff Missile; lb = pound(s); N/A = not applicable; SDB = Small-
  Diameter Bomb.

    The 780 TS, along with the Air Force Life Cycle Management Center 
and U.S. Navy, propose to jointly conduct air-to-air missile testing in 
the EGTTR. These missions would involve the use of the AIM-260A Joint 
Advanced Tactical Missile (JATM), AIM-9X Sidewinder, and AIM-120 AMRAAM 
missiles; all missiles used in these tests would be inert. Table 9 
presents information on the munitions proposed for air-to-air missile 
testing missions in the EGTTR during the 2023-2030 mission period.

[[Page 8156]]



                     Table 9--Proposed Munitions for Air-to-Air Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive         Detonation
              Type                      Category          weight  (lb)          scenario        Annual quantity
----------------------------------------------------------------------------------------------------------------
AIM-260 JATM--Inert.............  Missile............                N/A  N/A................                  6
AIM-9X--Inert...................  Missile............                N/A  N/A................                 10
AIM-120 AMRAAM--Inert...........  Missile............                N/A  N/A................                 15
----------------------------------------------------------------------------------------------------------------
AIM = Air Intercept Missile; AMRAAM = Advanced Medium-Range Air-to-Air Missile; EGTTR = Eglin Gulf Test and
  Training Range; lb = pound(s); JATM = Joint Advanced Tactical Missile; N/A = not applicable.

    The 780 TS proposes to test the ability of the AGM-114L Longbow 
missile and AGM-179A Joint Air-to-Ground Missile (JAGM) missile to 
track and impact moving target boats in the EGTTR as shown in Table 10. 
These missiles are typically launched from an AH-64D Apache helicopter. 
The test targets would be remotely controlled boats, including the 25-
foot High-Speed Maneuverable Surface Target (HSMST) (foam filled) and 
41-foot (12.5 m) Coast Guard Utility Boat (metal hull). The missiles 
would be launched approximately 0.9 to 4.3 nmi (1.7 to 7.9 km) from the 
targets.

                 Table 10--Proposed Munitions for Longbow and JAGM Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive         Detonation
              Type                      Category       weight  (lb)/(kg)        scenario        Annual quantity
----------------------------------------------------------------------------------------------------------------
AGM-114L Longbow................  Missile............       35.95 (16.3)  HOB................                  6
AGM-179A JAGM...................  Missile............       27.47 (11.1)  HOB................                  8
----------------------------------------------------------------------------------------------------------------
AGM = Air-to-Ground Missile; EGTTR = Eglin Gulf Test and Training Range; HOB = height of burst; JAGM = Joint Air-
  to-Ground Missile; lb = pound(s).

    The 780 TS proposes to test the Spike Non-Line-of-Sight (NLOS) air-
to-surface tactical missile system against static and moving target 
boats in the EGTTR in support of the U.S. Army's initiative to 
incorporate the Spike NLOS missile system onto the AH-64E Apache 
helicopter. These missiles shown in Table 11 would be launched from an 
AH-64D Apache helicopter and the test targets would include foam-filled 
fiberglass boats approximately 25 ft (7.62 m) in length that are either 
anchored or towed by a remotely controlled (HSMST).

                    Table 11--Proposed Munitions for NLOS Spike Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive        Detonation
              Type                     Category        weight  (lb)/(kg)       scenario         Annual quantity
----------------------------------------------------------------------------------------------------------------
Spike NLOS......................  Missile...........       34.08 (14.5)   Surface...........                  3
----------------------------------------------------------------------------------------------------------------

    The 780 TS proposes to conduct surface-to-air testing of Patriot 
Advanced Capability (PAC)-2 and PAC-3 missiles in the EGTTR. These 
missiles are expected to be fired from the A-15 launch site on Santa 
Rosa Island at drones in the EGTTR. Detailed operational data for this 
testing are not yet available. Standard inventory missiles would be 
used and up to eight PAC-2 tests and two PAC-3 tests per year are 
proposed as shown in Table 12.

                      Table 12--Proposed Munitions for Patriot Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive         Detonation
              Type                      Category       weight  (lb)/(kg)        scenario        Annual quantity
----------------------------------------------------------------------------------------------------------------
PAC-2...........................  Missile............    \a\145.0 (65.7)  N/A (drone target).                  8
PAC-3...........................  Missile............    \a\145.0 (65.7)  N/A (drone target).                  2
----------------------------------------------------------------------------------------------------------------
\a\ Assumed for impact analysis.

    Hypersonic weapons are capable of traveling at least five times the 
speed of sound, referred to as Mach 5. While conventional weapons 
typically rely on explosive warheads to inflict damage on a target, 
hypersonic weapons typically rely on kinetic energy from high-velocity 
impact to inflict damage on targets. For the purpose of assessing 
impacts, the kinetic energy of a hypersonic weapon may be correlated to 
energy release in units of feet-lb or trinitrotoluene (TNT) 
equivalency.
    The 780 TS supports several hypersonic weapon programs, including 
the Hypersonic Attack Cruise Missile (HACM) and Precision Strike 
Missile (PrSM) programs, which are presented in Table 13.
    HACM is a developmental air-breathing hypersonic cruise missile 
that uses scramjet technology for propulsion. This weapon would air-
launched. The 780 TS proposes to conduct HACM

[[Page 8157]]

testing, which would involve air launches through a north-south 
corridor within the EGTTR to a target location on the water surface. 
The dimensions and orientation of the test flight corridor within the 
EGTTR for HACM tests are to be determined; the flight corridor is 
preliminarily expected to be 300 to 400 nmi (555 to 740 km) in total 
length. Live HACMs would be fired from the southern portion of the 
EGTTR into either the existing LIA or proposed East LIA. Up to two live 
HACMs per year are proposed to be tested in the EGTTR during the 2023-
2030 mission period.
    The PrSM is being developed by the U.S. Army as a surface-to-
surface, long-range, precision-strike guided missile to be fired from 
the M270A1 Multiple Launch Rocket System and the M142 High Mobility 
Artillery Rocket System. The 780 TS in coordination with the U.S. Army 
proposes to conduct PrSM testing in the EGTTR. Some PrSM testing is 
expected to involve surface launches of the PrSM from the A-15 launch 
site on Santa Rosa Island. The dimensions and orientation of the test 
flight corridor within the EGTTR for PrSM tests are to be determined; 
the flight corridor is preliminarily expected to be 162 to 270 nmi (300 
to 500 km) in total length. For tests that involve a live warhead on 
the PrSM, the PrSM would be preset to detonate at a specific height 
above the water surface (HOB/airburst) and could occur in any portion 
of the EGTTR. Any surface strikes proposed with live PrSMs would be 
required to be in the existing LIA or proposed East LIA. Like inert 
HACM tests, inert PrSM tests could occur in any portion of the EGTTR, 
except between the 100-m and 400-m isobaths to prevent impacts to the 
Rice's whale.

                     Table 13--Proposed Munitions for Hypersonic Weapon Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive         Detonation
              Type                      Category       weight  (lb)/(kg)        scenario        Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
    HACM........................  Hypersonic Weapon..     \a\350 (158.7)  Surface............                  2
    PrSM........................  Hypersonic Weapon..      \a\46 (158.7)  HOB................                  2
Inert Munitions:
    PrSM--Inert.................  Hypersonic Weapon..                N/A  N/A................                  2
----------------------------------------------------------------------------------------------------------------
\a\ Net explosive weight at impact/detonation.

    The 780 TS, in coordination with the Air Force Research Laboratory, 
proposes to conduct SINKEX testing in the EGTTR. SINKEX exercises would 
involve the sinking of vessels, typically 200-400 ft (61 -122 m) in 
length, in the existing LIA. The types of munitions that would be used 
for SINKEX testing is controlled information and, therefore, not 
identified (Table 14).

                                Table 14--Proposed SINKEX Exercises in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                          Net explosive        Detonation
              Type                      Category          weight  (lb)          scenario        Annual quantity
----------------------------------------------------------------------------------------------------------------
SINKEX..........................  Vessel Sinking       Not Available.....  Not Available.....                  2
                                   Exercise.
----------------------------------------------------------------------------------------------------------------

    The 780 TS plans to lead or support other types of testing in the 
EGTTR as shown in Table 15. These missions would primarily include 
testing live and inert munitions against targets on the water surface, 
such as boats and barges. Some of the tests would involve munitions 
with NEWs of up to 945 lb, which is the highest NEW associated with the 
munitions analyzed in this LOA application.

                                      Table 15--Proposed Munitions for Other 780 Test Squadron Testing in the EGTTR
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Net explosive weight
                Type                          Category                (lb)/(kg)         Detonation  scenario         Target type        Annual quantity
--------------------------------------------------------------------------------------------------------------------------------------------------------
Live Munitions:
    GBU-10, 24, or 31 (QUICKSINK)...  Bomb...................  945 (428.5)...........  Subsurface............  TBD...................             4 to 8
    2,000 lb bomb with JDAM kit.....  Bomb...................  945 (428.5) or less...  HOB...................  TBD...................                  2
    Inert GBU-39 (LSDB).............  Bomb...................  0.4 (0.2).............  HOB/Surface...........  Small Boat............                  4
    with live fuze..................
    Inert GBU-53 (SDB II)...........  Bomb...................  0.4 (0.2).............  HOB/Surface...........  Small Boat............                  4
    with live fuze..................
Inert Munitions:
    SiAW AARGM-ER...................  Missile................  N/A...................  N/A...................  TBD...................                  7
Multipurpose Booster................  Booster................  N/A...................  N/A...................  TBD...................                  1
    JDAM ER.........................  Bomb...................  N/A...................  N/A...................  Water Surface and                       3
                                                                                                                Barge.

[[Page 8158]]

 
    Navy HAAWC......................  Torpedo................  N/A...................  N/A...................  Water Surface.........                  2
--------------------------------------------------------------------------------------------------------------------------------------------------------
AARGM-ER = Advanced Anti-Radiation Guided Missile--Extended Range; EGTTR = Eglin Gulf Test and Training Range; Guided Bomb Unit; HOB = height of burst;
  HAAWC = High Altitude Anti-Submarine Warfare Weapon Capability; JDAM = Joint Direct Attack Munition; lb = pound(s); LSDB = Laser Small-Diameter Bomb;
  N/A = not applicable; SDB = Small-Diameter Bomb; SiAW = Stand-in Attack Weapon; TBD = to be determined.

    The 96 OG proposes to continue expending approximately nine inert 
bombs a year in the EGTTR for testing purposes. The bombs are expected 
to be up to 2,000 lb (907 kg) in total weight. For the impact analysis, 
the bombs to be used by the 96 OG in the EGTTR during the 2023-2030 
mission period are assumed to be Mk-84 2,000 lb (907 kg) General 
Purpose (GP) inert bombs (Table 16).

                        Table 16--Proposed Munitions for Inert Bomb Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net explosive        Detonation
              Type                     Category          weight  (lb)          scenario         Annual quantity
----------------------------------------------------------------------------------------------------------------
Mk-84 (GP 2,000 lb) \a\.........  Bomb..............                N/A                 N/A                   9
----------------------------------------------------------------------------------------------------------------
\a\Assumed for impact analysis.
EGTTR = Eglin Gulf Test and Training Range; GP = General Purpose; lb = pound(s); Mk = Mark; N/A = not
  applicable.

Naval School Explosive Ordnance Disposal (NAVSCOLEOD)
    NAVSCOLEOD proposes to conduct training missions in the EGTTR which 
would include Countermeasures (MCM) exercises to teach NAVSCOLEOD 
students techniques for neutralizing mines underwater (Table 17). 
Underwater MCM training exercises are conducted in nearshore waters and 
primarily involve diving and placing small explosive charges adjacent 
to inert mines by hand; the detonation of such charges disables live 
mines. NAVSCOLEOD training is conducted offshore of Santa Rosa Island 
and in other locations and has not yet extended into the EGTTR. 
NAVSCOLEOD training proposed for the 2023-2030 mission period would 
extend approximately 5 nmi (9.26 km) offshore of Santa Rosa Island, in 
the EGTTR. Up to 8 MCM training missions would be conducted annually in 
the EGTTR during the 2023-2030 period. Each mission would involve 4 
underwater detonations of charges hand placed adjacent to inert mines, 
for a total of 32 annual detonations. The MCM neutralization charges 
consist of C-4 explosives, detonation cord, non-electric blasting caps, 
time fuzes, and fuze igniters; each charge has a NEW of approximately 
20 lb. (9.07 kg). During each mission, with a maximum of 4 charges, 
would detonate with a delay no greater than 20 minutes between shots. 
After the final detonation, or a delay greater than 20 minutes, a 30-
minute environmental observation would be conducted. Additionally, 
NAVSCOLEOD proposes to conduct up to 80 floating mine training 
missions, which would involve detonations of charges on the water 
surface; these charges would have a NEW of approximately 5 lb (2.3 kg). 
All NAVSCOLEOD missions would occur only during daylight hours.

                        Table 17--Proposed Munitions for NAVSCOLEOD Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
                                                         Net Explosive
              Type                      Category       weight  (lb)/(kg)  Detonation scenario   Annual quantity
----------------------------------------------------------------------------------------------------------------
Underwater Mine Charge..........  Charge.............        \a\20 (9.1)  Subsurface.........                 32
Floating Mine Charge............  Charge.............         \a\5 (2.3)  Surface............                 80
----------------------------------------------------------------------------------------------------------------
\a\ Estimated

Description of Stressors
    The USAF uses the EGTTR for training purposes and for testing of a 
variety of weapon systems described in this proposed rule. All of the 
weapons systems considered likely to cause the take of marine mammals 
involve explosive detonations. Training and testing with these systems 
may introduce acoustic (sound) energy or shock waves from explosives 
into the environment. The following section describes explosives 
detonated at or just below the surface of the water within the EGTTR. 
Because of the complexity of analyzing sound propagation in the ocean 
environment, the USAF relied on acoustic models in its environmental 
analyses and rulemaking/LOA application that considered sound source 
characteristics and conditions across the EGTTR.
    Explosive detonations at the water surface send a shock wave and 
sound energy through the water and can release gaseous by-products, 
create an oscillating bubble, or cause a plume of water to shoot up 
from the water surface. When an air-to-surface munition impacts the 
water, some of the kinetic energy displaces water in the formation of 
an impact ``crater'' in the water, some of the kinetic energy is 
transmitted from the impact point as underwater acoustic energy in a 
pressure impulse, and the remaining kinetic energy is retained by the 
munition continuing to move through the water. Following impact, the 
warhead of a live munition detonates at or slightly below the water 
surface. The warhead detonation converts explosive

[[Page 8159]]

material into gas, further displacing water through the rapid creation 
of a gas bubble in the water, and creates a much larger pressure wave 
than the pressure wave created by the impact. These impulse pressure 
waves radiate from the impact point at the speed of sound in water, 
roughly 1,500 m per second. If the detonation is sufficiently deep, the 
gas bubble goes through a series of expansions and contractions, with 
each cycle being of successively lower energy. When detonations occur 
below but near the water surface, the initial gas bubble reaches the 
surface and causes venting, which also dissipates energy through the 
ejection of water and release of detonation gases into the atmosphere. 
When a detonation occurs below the water surface after the impact 
crater has fully or partially closed, water can be violently ejected 
upward by the pressure impulse and through venting of the gas bubble 
formed by the detonation.
    With radii of up to 15 m, the gas bubbles that would be generated 
by EGTTR munition detonations would be larger than the depth of 
detonation but much smaller than the water depth, so all munitions 
analyzed are considered to fully vent to the surface without forming 
underwater bubble expansion and contraction cycles. When detonations 
occur at the water surface, a large portion of the energy and gases 
that would otherwise form a detonation bubble are reflected upward from 
the water. Likewise, when a shallow detonation occurs below the water 
surface but prior to the impact crater closing, considerable energy is 
reflected upward from the water. As a conservative assumption, no 
energy losses from surface effects are included in the acoustic model.
    The impulsive pressure waves generated by munition impact and 
warhead detonation radiate spherically and are reflected between the 
water surface and the sea bottom. There is generally some attenuation 
of the pressure waves by the sea bottom but relatively little 
attenuation of the pressure waves by the water surface. As a 
conservative assumption, the water surface is assumed to be flat (no 
waves) to allow for maximum reflectivity. Additionally, is it assumed 
that all detonations occur in the water and none of the detonations 
occur above the water surface when a munition impacts a target. This 
conservative assumption implies that all munition energy is imparted to 
the water rather than the intended targets. The potential impacts of 
exposure to explosive detonations are discussed in detail in the 
Potential Effects of Specified Activities on Marine Mammals and their 
Habitat section.

Description of Marine Mammals in the Area of the Specified Activities

    Table 18 lists all species or stocks for which take is expected and 
proposed to be authorized for this activity, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and Endangered Species Act (ESA) and potential biological 
removal (PBR), where known. PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS' 
SARs). While no serious injury or mortality is expected to occur, PBR 
and annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species or 
stocks and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All stocks managed under the MMPA in this region 
are assessed in NMFS' 2021 U.S. Atlantic and Gulf of Mexico Marine 
Mammal Stock Assessment (Hayes et al. 2022; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports). All values presented in Table 18 are the 
most recent available at the time of publication and are available 
online at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments).

                                    Table 18--Marine Mammals Potentially Present in the Specified Geographical Region
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                             NMFS stock abundance
                                                                                         ESA/MMPA status;   (CV, Nmin, most recent             Annual M/
             Common name                  Scientific name               Stock             strategic (Y/N)    abundance survey) \2\     PBR       SI \3\
                                                                                                \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals):
    Rice's whale \4\................  Balaenoptera ricei.....  Gulf of Mexico.........  E/D; Y              51 (0.50; 34; 2017-18)        0.1        0.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Common bottlenose dolphin.......  Tursiops 939runcates     Northern GOM             -; N                63,280 (0.11; 57,917;         556         65
                                       truncatus.               Continental Shelf.                           2018).
    Atlantic spotted dolphin........  Stenella frontalis.....  GOM....................  -; N                21,506 (0.26; 17,339;         166         36
                                                                                                             2017-18).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered/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.
\2\ NMFS marine mammal stock assessment reports online at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments. CV
  is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality (M) plus serious injury (SI) from all sources combined (e.g.,
  commercial fisheries, ship strike). These values are generally considered minimums because, among other reasons, not all fisheries that could interact
  with a particular stock are observed and/or observer coverage is very low, and, for some stocks (such as the Atlantic spotted dolphin and continental
  shelf stock of bottlenose dolphin), no estimate for injury due to the Deepwater Horizon oil spill has been included. See SARs for further discussion.
\4\ The 2021 final rule refers to the Gulf of Mexico (GOM) Bryde's whale (Balaenoptera edeni). These whales were subsequently described as a new
  species, Rice's whale (Balaenoptera ricei) (Rosel et al., 2021).


[[Page 8160]]

    As indicated above, all three species (with three managed stocks) 
in Table 18 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur. These species are 
generally categorized into those species that occur over the 
continental shelf, which is typically considered to extend from shore 
to the 200-m (656-ft) isobath, and those species that occur beyond the 
continental shelf break in waters deeper than 200 m. Since water depths 
range from approximately 30 to 145 m in the existing LIA and from 
approximately 35 to 95 m in the proposed new East LIA, most of EGTTR 
activities would occur in waters over the continental shelf. Any live 
munitions would be set to detonate above the water surface if used 
outside the LIA beyond the 200-m isobath. Airburst detonations are not 
considered to affect marine mammals because there is little 
transmission of pressure or sound energy across the air-water 
interface. For these reasons, only cetacean species that predominantly 
occur landward of the 200-m isobath are carried forward in the 
analysis. These species include common bottlenose dolphin, Atlantic 
spotted dolphin, and Rice's whale.

Common Bottlenose Dolphin

    The common bottlenose dolphin is abundant in the northeastern Gulf 
from inshore to upper continental slope waters less than 1,000 m deep 
(Mullin and Fulling 2004). It is the most common cetacean species found 
in the coastal waters of the Gulf of Mexico. Genetically distinct 
coastal and offshore ecotypes of the bottlenose dolphin occur in the 
Gulf of Mexico and in other locations (Hoelzel et al. 1998). A total of 
36 common bottlenose dolphin stocks have been identified in the 
northern Gulf of Mexico including coastal, continental shelf, and 
oceanic stocks, as well as 31 bay, sound, and estuarine stocks (Waring 
et al. 2016). Stocks that may be found near or within the EGTTR include 
the Gulf of Mexico Northern Coastal, Northern Gulf of Mexico 
Continental Shelf, and Northern Gulf of Mexico Oceanic stocks, in 
addition to three inshore stocks, which include the Choctawhatchee Bay, 
Pensacola/East Bay, and St. Andrew Bay stocks. However, the designated 
inshore stock areas are landward of the EGTTR boundary; therefore, 
individuals from these stocks are not anticipated to be exposed to or 
affected by EGTTR operations. The Gulf of Mexico Northern Coastal Stock 
inhabits waters from shore to the 20-m (65-ft) isobath and, therefore, 
has potential to occur within the EGTTR, which starts at 3 nmi (5.5 km) 
offshore, where water depths can be 20 m or slightly less. However, 
given that most EGTTR operations would occur in either the existing 
LIA, where water depths range from approximately 30 to 145 m, or in the 
proposed East LIA, where water depths range from approximately 35 to 85 
m, EGTTR operations are expected to have no appreciable effect on this 
stock. The Northern Gulf of Mexico Continental Shelf Stock inhabits 
waters that are 20 to 200 m deep and, therefore, is expected to be the 
primary bottlenose dolphin stock that occurs in the existing LIA. The 
Northern Gulf of Mexico Oceanic Stock inhabits waters deeper than 200 m 
and, therefore, is not expected to be exposed to or affected by EGGTR 
operations in either LIA.
    The bottlenose dolphin reaches a length ranging from about 6 to 13 
ft (1.8 to 3.9 m) and a weight ranging from about 300 to 1,400 lb (136 
to 635 kg). The diet of bottlenose dolphins consists primarily of fish, 
squid, and crustaceans. They hunt for prey using a variety of 
techniques individually and cooperatively. For example, they may work 
as a group to herd and trap fish as well as use high-frequency 
echolocation, to catch prey.

Atlantic Spotted Dolphin

    The Atlantic spotted dolphin occurs throughout the Atlantic Ocean 
and the Gulf of Mexico. There is a single stock of the Atlantic spotted 
dolphin in U.S. Gulf waters, which is the Northern Gulf of Mexico 
Stock. Animals occur primarily from continental shelf waters of 10-200 
m deep to slope waters <500 m deep and were spotted in all seasons 
during aerial and vessel surveys of the northern Gulf of Mexico (i.e., 
U.S. Gulf of Mexico; Hansen et al. 1996; Mullin and Hoggard 2000; 
Fulling et al. 2003; Mullin and Fulling 2004; Maze-Foley and Mullin 
2006). Atlantic spotted dolphins are about 5 to 7.5 ft (1.5 to 2.3 m) 
long and weigh about 220 to 315 lb (99.8 to 142.8 kg). Their diet 
consists primarily of small fish, invertebrates, and cephalopods, which 
they catch using a variety of techniques including echolocation. 
Atlantic spotted dolphins are social animals and form groups of up to 
200 individuals. Most groups consist of fewer than 50 individuals, and 
in coastal waters groups typically consist of 5 to 15 individuals (NMFS 
2021b).

Rice's Whale

    The Gulf of Mexico Bryde's whale was listed as endangered 
throughout its entire range on April 15, 2019, under the Endangered 
Species Act (ESA). Based on genetic analyses and new morphological 
information NOAA Fisheries recently revised the common and scientific 
names to recognize this new species (Balaenoptera ricei) as being 
separate from other Bryde's whale populations (86 FR 47022; August 21, 
2021). Rosel and Wilcox (2014) first identified a new, evolutionarily 
distinct lineage of whale in the Gulf of Mexico. Genetic analysis of 
whales sampled in the northeastern Gulf of Mexico revealed that this 
population is evolutionarily distinct from all other whales within the 
Bryde's whale complex and all other known balaenopterid species (Rosel 
and Wilcox 2014).
    The Rice's whale is the only year-round resident baleen whale 
species in the Gulf of Mexico. Rosel et.al. (2021) reported that based 
on a compilation of sighting and stranding data from 1992 to 2019, the 
primary habitat of the Rice's whale is the northeastern Gulf of Mexico, 
particularly the De Soto Canyon area, at water depths of 150 to 410 m.
    Biologically Important Areas (BIAs) include areas of known 
importance for reproduction, feeding, or migration, or areas where 
small and resident populations are known to occur (Van Parijs, 2015). 
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. In 
2015, a year round small and resident population BIA for Bryde's whales 
(later designated as Rice's whales) was identified from the De Soto 
Canyon along the shelf break to the southeast (LaBrecque et al. 2015). 
The 23,559 km\2\ BIA covers waters between 100 and 300 m deep from 
approximately south of Pensacola to approximately west of Fort Myers, 
FL (LaBrecque et al. 2015). The deepest location where a Rice's whale 
has been sighted is 408 m (Rosel et al. 2021). Habitat for the Rice's 
whale is currently considered by NMFS to be primarily within the depth 
range of 100 to 400 m in this part of the Gulf of Mexico (NMFS 2016, 
2020a), and in 2019 NMFS delineated a Core Distribution Area (https://www.fisheries.noaa.gov/resource/map/rices-whale-core-distribution-area-map-gis-data) based on visual and tag data available through 2019. No 
critical habitat has yet been designated for the species, and no 
recovery plan has yet been developed.
    The Rice's whale is a medium-sized baleen whale. To date, the 
largest verified Rice's whale to strand was a lactating female about 
12.65 m long; the largest male was 11.26 m (Rosel et al. 2021). Little 
is known about their

[[Page 8161]]

foraging ecology and diet. However, data from two Rice's whales suggest 
they may mostly forage at or near the seafloor.

Unusual Mortality Events (UMEs)

    An UME is defined under Section 410(6) of the MMPA as a stranding 
that is unexpected; it involves a significant die-off of any marine 
mammal population and demands immediate response. There are currently 
no UMEs with ongoing investigations in the EGTTR. There was a UME for 
bottlenose dolphins that was active beginning in February 2019 and 
closing in November of the same year that included the northern Gulf of 
Mexico. Dolphins developed lesions that were thought to be caused by 
exposure to low salinity water stemming from extreme freshwater 
discharge. This UME is closed.

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, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). Note that no direct measurements of 
hearing ability have been successfully completed for mysticetes (i.e., 
low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 19.

                 Table 19--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans.........  7 Hz to 35 kHz.
(baleen whales)......................
Mid-frequency (MF) cetaceans.........  150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans........  275 Hz to 160 kHz.
(true porpoises, Kogia, river
 dolphins, Cephalorhynchid,
 Lagenorhynchus cruciger & L.
 australis).
Phocid pinnipeds (PW) (underwater)...  50 Hz to 86 kHz.
(true seals).........................
Otariid pinnipeds (OW) (underwater)..  60 Hz to 39 kHz.
(sea lions and fur seals)............
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al. 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary of the ways that components of the 
specified activity may impact marine mammals and their habitat. The 
Estimated Take of Marine Mammals section later in this rule includes a 
quantitative analysis of the number of instances of take that could 
occur from these activities. 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 USAF has requested authorization for the take of marine mammals 
that may occur incidental to training and testing activities in the 
EGTTR. The USAF analyzed potential impacts to marine mammals from air-
to-surface operations that involve firing live or inert munitions, 
including missiles, bombs, and gun ammunition, from aircraft at targets 
on the water surface in the LOA application as well as the 2022 REA, 
for which NMFS served as a cooperating agency. The proposed training 
and testing exercises have the potential to cause take of marine 
mammals by exposing them to impulsive noise and pressure waves 
generated by explosive detonation at or near the surface of the water. 
Exposure to noise or pressure resulting from these detonations could 
result in non-lethal injury (Level A harassment) or disturbance (Level 
B harassment). As explained in the Estimated Take of Marine Mammals 
section, neither mortality nor non-auditory injury are anticipated or 
authorized.
    A summary of the potential impacts of the pressure waves generated 
by explosive detonations is included below. Following, a brief 
technical background is provided here on sound, on the characteristics 
of certain sound types, and on metrics used in this proposal. Last, a 
brief overview of the potential effects (e.g., tolerance, masking, 
hearing threshold shift, behavioral disturbance, and stress responses) 
to marine mammals associated with the USAF's proposed activities is 
included.

[[Page 8162]]

Impacts from Pressure Waves Caused by Explosive Detonations

    Exposure to the pressure waves generated by explosive detonations 
has the potential to cause injury, serious injury, or mortality, 
although those impacts are not anticipated here. (This conclusion is 
based on the size, type, depth, and duration of the explosives in 
combination with the density of marine mammals, which together predict 
a low probability of exposures, as well as the required mitigation 
measures, as described in detail the Estimated Take of Marine Mammals 
section.) The potential acoustic impacts of explosive detonations 
(e.g., permanent threshold shift (PTS), temporary threshold shift 
(TTS), and behavioral disturbance) are described in subsequent 
sections.
    Generally speaking, the pressure from munition detonations have the 
potential to cause mortality, injury, hearing impairment, or behavioral 
disturbances in marine mammals, depending on the explosive energy 
released by the munition and the distance of the animal from the 
detonation. The impulsive noise from these detonations may also cause 
hearing impairment or behavioral disturbances. The most potentially 
severe effects would occur close to the detonation point, including 
tissue damage, barotrauma, or even death. Serious injury or mortality 
to marine mammals from explosive detonations, if they occurred, which 
is not expected here, would consist of primary blast injury, which 
refers to those injuries that result from the compression of a body 
exposed to a blast wave and which is usually observed as barotrauma of 
gas-containing structures (e.g., lung and gut) and structural damage to 
the auditory system (Richmond et al. 1973). The near instantaneous high 
magnitude pressure change near an explosion can injure an animal where 
tissue material properties significantly differ from the surrounding 
environment, such as around air-filled cavities in the lungs or 
gastrointestinal (GI) tract. The gas-containing organs (lungs and GI 
tract) are most vulnerable to primary blast injury. Severe injuries to 
these organs are presumed to result in mortality (e.g., severe lung 
damage may introduce air into the cardiopulmonary vascular system, 
resulting in lethal air emboli). Large pressure changes at tissue-air 
interfaces in the lungs and GI tract may cause tissue rupture, 
resulting in a range of injuries depending on degree of exposure. 
Recoverable injuries would include slight lung injury, such as 
capillary interstitial bleeding, and contusions to the GI tract. More 
severe injuries, such as tissue lacerations, major hemorrhage, organ 
rupture, or air in the chest cavity (pneumothorax), would significantly 
reduce fitness and likely cause death in the wild. Rupture of the lung 
may also introduce air into the vascular system, producing air emboli 
that can cause a stroke or heart attack and restrict oxygen delivery to 
critical organs. Susceptibility would increase with depth, until normal 
lung collapse (due to increasing hydrostatic pressure) and increasing 
ambient pressures again reduce susceptibility.
    Exposures to higher levels of impulse and pressure levels would 
generally result in greater impacts to an individual animal. However, 
the effects of noise on marine mammals are highly variable, often 
depending on species and contextual factors (Richardson et al. 1995). 
As described in the Estimated Take of Marine Mammals section, the more 
serious impacts (i.e., mortality, serious injury, and non-auditory 
injury) are not anticipated to result from this action.
    The USAF performed a quantitative analysis to estimate the 
probability that marine mammals could be exposed to the sound and 
energy from explosions during USAF activities and the effects of those 
exposures (Appendix A in LOA Application). The effects of underwater 
explosions on marine mammals depend on a variety of factors including 
animal size and depth; charge size and depth; depth of the water 
column; and distance between the animal and the charge. In general, an 
animal would be less susceptible to injury near the water surface 
because the pressure wave reflected from the water surface would 
interfere with the direct path pressure wave, reducing positive 
pressure exposure. There are a limited number of explosives that would 
detonate just below the water surface as outlined previously in the 
section, Description of Stressors. Most explosives would detonate at or 
near the surface of the water and are unlikely to transfer energy 
underwater sufficient to result in non-auditory injury (GI injury or 
lung injury) or mortality. For reasons described in the Estimated Take 
of Marine Mammals section, NMFS agrees with USAF's analysis that no 
mortality or serious injury from tissue damage in the form of GI injury 
or lung injury is anticipated to result from the proposed activities. 
The USAF did not request, and NMFS does not propose, mortality or 
serious injury for authorization, and therefore this proposed rule will 
not discuss it further. For additional details on the criteria for 
estimating non-auditory physiological impacts on marine mammals due to 
naval underwater explosions, we refer the reader to the report, 
Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects 
Analysis (Phase III) (U.S. Department of the Navy, 2017e).
    Sections 6, 7, and 9 of the USAF's application include summaries of 
the ways that components of the specified activity may impact marine 
mammals and their habitat, including specific discussion of potential 
effects to marine mammals from noise and pressure waves produced 
through the use explosives detonating at or near the surface. We have 
reviewed the USAF's discussion of potential effects for accuracy and 
completeness in its application and refer to that information rather 
than repeating it in full here. Below we include a summary of the 
potential effects to marine mammals.

Description of Sound Sources

    This section contains a brief technical background on sound, on the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document. For general 
information on sound and its interaction with the marine environment, 
please see Au and Hastings (2008); Richardson et al. (1995); and Urick 
(1983).
    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in hertz or cycles per second. Wavelength is the distance 
between two peaks or corresponding points of a sound wave (length of 
one cycle). Higher frequency sounds have shorter wavelengths than lower 
frequency sounds, and typically attenuate (decrease) more rapidly, 
except in certain cases in shallower water. Amplitude is the height of 
the sound pressure wave or the ``loudness'' of a sound and is typically 
described using the relative unit of the decibel (dB). A sound pressure 
level (SPL) in dB is described as the ratio between a measured pressure 
and a reference pressure (for underwater sound, this is 1 microPascal 
([mu]Pa)), and is a logarithmic unit that accounts for large variations 
in amplitude. Therefore, a relatively small change in dB corresponds to 
large changes in sound pressure. The source level (SL) represents the 
SPL referenced at a distance of 1 m from the source (referenced to 1 
[mu]Pa), while the received level is the SPL at the listener's position 
(referenced to 1 [mu]Pa).

[[Page 8163]]

    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Root mean square is calculated by squaring 
all of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick 1983). Root mean square accounts for 
both positive and negative values; squaring the pressures makes all 
values positive so that they may be accounted for in the summation of 
pressure levels (Hastings and Popper 2005). This measurement is often 
used in the context of discussing behavioral effects, in part because 
behavioral effects, which often result from auditory cues, may be 
better expressed through averaged units than by peak pressures.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy in a stated frequency band over a stated 
time interval or event and considers both intensity and duration of 
exposure. The per-pulse SEL is calculated over the time window 
containing the entire pulse (i.e., 100 percent of the acoustic energy). 
SEL is a cumulative metric; it can be accumulated over a single pulse, 
or calculated over periods containing multiple pulses. Cumulative SEL 
represents the total energy accumulated by a receiver over a defined 
time window or during an event. Peak sound pressure (also referred to 
as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous 
sound pressure measurable in the water at a specified distance from the 
source and is represented in the same units as the rms sound pressure.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in a 
manner similar to ripples on the surface of a pond and may be either 
directed in a beam or beams or may radiate in all directions 
(omnidirectional sources). The compressions and decompressions 
associated with sound waves are detected as changes in pressure by 
aquatic life and man-made sound receptors such as hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound, which is 
defined as environmental background sound levels lacking a single 
source or point (Richardson et al. 1995). The sound level of a region 
is defined by the total acoustical energy being generated by known and 
unknown sources. These sources may include physical (e.g., wind and 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
(e.g., vessels, dredging, construction) sound. A number of sources 
contribute to ambient sound, including wind and waves, which are a main 
source of naturally occurring ambient sound for frequencies between 200 
Hz and 50 kHz (Mitson 1995). In general, ambient sound levels tend to 
increase with increasing wind speed and wave height. Precipitation can 
become an important component of total sound at frequencies above 500 
Hz, and possibly down to 100 Hz during quiet times. Marine mammals can 
contribute significantly to ambient sound levels, as can some fish and 
snapping shrimp. The frequency band for biological contributions is 
from approximately 12 Hz to over 100 kHz. Sources of ambient sound 
related to human activity include transportation (surface vessels), 
dredging and construction, oil and gas drilling and production, 
geophysical surveys, sonar, and explosions. Vessel noise typically 
dominates the total ambient sound for frequencies between 20 and 300 
Hz. In general, the frequencies of anthropogenic sounds are below 1 kHz 
and, if higher frequency sound levels are created, they attenuate 
rapidly.
    The sum of the various natural and anthropogenic sound sources that 
comprise ambient sound at any given location and time depends not only 
on the source levels (as determined by current weather conditions and 
levels of biological and human 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 decibels (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 activity may be a negligible addition to the 
local environment or could form a distinctive signal that may affect 
marine mammals. Details of source types are described in the following 
text.
    Sounds are often considered to fall into one of two general types: 
Pulsed and non-pulsed (defined in the following). The distinction 
between these two sound types is important because they have differing 
potential to cause physical effects, particularly with regard to 
hearing (e.g., Ward 1997 in Southall et al. 2007). Please see Southall 
et al. (2007) and NMFS' Technical Guidance for Assessing the Effects of 
Anthropogenic Sound on Marine Mammal Hearing (Version 2.0) Underwater 
Thresholds for Onset of Permanent and Temporary Threshold Shift 
(Acoustic Technical Guidance) (NMFS 2018) for an in-depth discussion of 
these concepts. The distinction between these two sound types is not 
always obvious, as certain signals share properties of both pulsed and 
non-pulsed sounds. A signal near a source could be categorized as a 
pulse, but due to propagation effects as it moves farther from the 
source, the signal duration becomes longer (e.g., Greene and Richardson 
1988).
    Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic 
booms, impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI 1986, 2005; Harris 1998; NIOSH 1998; ISO 2003) and occur either 
as isolated events or repeated in some succession. Pulsed sounds are 
all characterized by a relatively rapid rise from ambient pressure to a 
maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband or broadband, brief or 
prolonged, and may be either continuous or intermittent (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems. The 
duration of such sounds, as received at a distance, can be greatly 
extended in a highly reverberant environment.

Hearing Loss--Threshold Shift

    Marine mammals exposed to high-intensity sound, or to lower-
intensity sound for prolonged periods, can experience hearing threshold 
shift, which is the loss of hearing sensitivity at certain frequency 
ranges after cessation of sound (Finneran 2015). Threshold shift can be 
permanent (PTS), in which case the loss of hearing sensitivity is not 
fully recoverable, or temporary (TTS), in which case the animal's 
hearing threshold would recover over time (Southall et al. 2007).

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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). PTS is considered an injury and Level A 
harassment while TTS is considered to be Level B harassment and not 
considered an injury.
    Hearing loss, or threshold shift (TS), is typically quantified in 
terms of the amount (in decibels) that hearing thresholds at one or 
more specified frequencies are elevated, compared to their pre-exposure 
values, at some specific time after the noise exposure. The amount of 
TS measured usually decreases with increasing recovery time--the amount 
of time that has elapsed since a noise exposure. If the TS eventually 
returns to zero (i.e., the hearing threshold returns to the pre-
exposure value), the threshold shift is called a TTS. If the TS does 
not completely recover (the threshold remains elevated compared to the 
pre-exposure value), the remaining TS is a PTS.
    Hearing loss has only been studied in a few species of marine 
mammals, although hearing studies with terrestrial mammals are also 
informative. There are no direct measurements of hearing loss in marine 
mammals due to exposure to explosive sources. The sound resulting from 
an explosive detonation is considered an impulsive sound and shares 
important qualities (i.e., short duration and fast rise time) with 
other impulsive sounds such as those produced by air guns. General 
research findings regarding TTS and PTS in marine mammals, as well as 
findings specific to exposure to other impulsive sound sources, are 
discussed below.
    Many studies have examined noise-induced hearing loss in marine 
mammals (see Finneran (2015) and Southall et al. (2019) for summaries), 
however for cetaceans, published data on the onset of TTS are limited 
to the captive bottlenose dolphin, beluga, harbor porpoise, and Yangtze 
finless porpoise, and, for pinnipeds in water, measurements of TTS are 
limited to harbor seals, elephant seals, and California sea lions. 
These studies examine hearing thresholds measured in marine mammals 
before and after exposure to intense sounds. The difference between the 
pre-exposure and post-exposure thresholds can then be used to determine 
the amount of threshold shift at various post-exposure times. NMFS has 
reviewed the available studies, which are summarized below:
     The method used to test hearing 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).
     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. 2014). 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; Kastelein et al. 2021b; Kastelein et al. 2022). 
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.
     Gradual increases of TTS may not be directly observable 
with increasing exposure levels before the onset of PTS (Reichmuth et 
al. 2019). Similarly, PTS can occur without measurable behavioral 
modifications (Reichmuth et al. 2019).
     The amount of TTS depends on the exposure frequency. 
Sounds at low frequencies, well below the region of best sensitivity, 
are less hazardous than those at higher frequencies, near the region of 
best sensitivity (Finneran and Schlundt, 2013). The onset of TTS--
defined as the exposure level necessary to produce 6 dB of TTS (i.e., 
clearly above the typical variation in threshold measurements)--also 
varies with exposure frequency. At low frequencies, onset-TTS exposure 
levels are higher compared to those in the region of best sensitivity. 
For example, for harbor porpoises exposed to one-sixth octave noise 
bands at 16 kHz (Kastelein et al. 2019a), 32 kHz (Kastelein et al. 
2019b), 63 kHz (Kastelein et al. 2020a), and 88.4 kHz (Kastelein et al. 
2020b), less susceptibility to TTS was found as frequency increased, 
whereas exposure frequencies below ~6.5 kHz showed an increase in TTS 
susceptibility as frequency increased and approached the region of best 
sensitivity. Kastelein et al. (2020b) showed a much higher onset of TTS 
for a 88.5 kHz exposure as compared to lower exposure frequencies 
(i.e., 16 kHz (Kastelein et al., 2019) 1.5 kHz and 6.5 kHz (Kastelein 
et al. 2020a)). For the 88.4 kHz test frequency, a 185 dB re 1 
micropascal squared per second ([micro]Pa\2\ -s) exposure resulted in 
3.6 dB of TTS, and a 191 dB re 1 [micro]Pa\2\ -s exposure produced 5.2 
dB of TTS at 100 kHz and 5.4 dB of TTS at 125 kHz. Together, these new 
studies demonstrate that the criteria for high-frequency (HF) cetacean 
auditory impacts is likely to be conservative.
     TTS can accumulate across multiple exposures, but the 
resulting TTS will be less than the TTS from a single, continuous 
exposure with the same SEL (Finneran et al. 2010a; Kastelein et al. 
2014b; Kastelein et 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 importance of duty cycle in predicting the 
likelihood of TTS is demonstrated further in Kastelein et al. (2021b). 
The authors found that reducing the duty cycle of a sound generally 
reduced the potential for TTS in California sea lions, and that, 
further, California sea lions are more susceptible to TTS than 
previously believed at the 2 and 4 kHz frequencies tested.
     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

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shifts (e.g., approximately 40 dB) may require several days for 
recovery. Recovery times are consistent for similar-magnitude TTS, 
regardless of the type of fatiguing sound exposure (impulsive, 
continuous noise band, or sinusoidal wave; (Kastelein et al. 2019c)). 
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. 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. Another study showed that echolocating animals 
(including odontocetes) might have anatomical specializations that 
might allow for conditioned hearing reduction and filtering of low-
frequency ambient noise, including increased stiffness and control of 
middle ear structures and placement of inner ear structures (Ketten et 
al. 2021). Finneran 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 TTS data from impulsive sources are limited. Two 
studies with measured TTS of 6 dB or more, with Finneran et al. (2002) 
reporting behaviorally measured TTSs of 6 and 7 dB in a beluga exposed 
to single impulses from a seismic water gun, and with Lucke et al. 
(2009) reporting Audio-evoked Potential measured TTS of 7-20 dB in a 
harbor porpoise exposed to single impulses from a seismic air gun. 
Kastelein et al. (2017) quantified TTS caused by exposure to 10-20 
consecutive shots from 2 airguns simultaneously in harbor porpoises. 
Statistically significant initial TTS (1-4 min after sound exposure 
stopped) of ~4.4 dB occurred. However, recovery occurred within 12 min 
post-exposure.
    Several impulsive noise exposure studies have also been conducted 
without behaviorally measurable TTS. Specifically, Finneran et al. 
(2000) exposed dolphins and belugas to single impulses from an 
explosion simulator, and Finneran et al. (2015) exposed three dolphins 
to sequences of 10 impulses from a seismic air gun (maximum cumulative 
SEL = 193-195 dB re 1 [mu]Pa\2\s, peak SPL =196-210 dB re 1 [mu]Pa) 
without measurable TTS. The proposed activities include both TTS and a 
limited amount of PTS in some marine mammals.

Behavioral Disturbance

    Behavioral responses to sound are highly variable and context-
specific. Many different variables can influence an animal's perception 
of and response to an acoustic event. An animal's prior experience with 
a sound or sound source affects whether it is less likely (habituation) 
or more likely (sensitization) to respond to certain sounds in the 
future (animals can also be innately predisposed to respond to certain 
sounds in certain ways) (Southall et al. 2007). Related to the sound 
itself, the perceived nearness of the sound, bearing of the sound 
(approaching vs. retreating), the similarity of a sound to biologically 
relevant sounds in the animal's environment (i.e., calls of predators, 
prey, or conspecifics), and familiarity of the sound may affect the way 
an animal responds to the sound (Southall et al.2007, DeRuiter et al. 
2013). Individuals (of different age, gender, reproductive status, 
etc.) among most populations will have variable hearing capabilities, 
and differing behavioral sensitivities to sounds that will be affected 
by prior conditioning, experience, and current activities of those 
individuals. Often, specific acoustic features of the sound and 
contextual variables (i.e., proximity, duration, or recurrence of the 
sound or the current behavior that the marine mammal is engaged in or 
its prior experience), as well as entirely separate factors such as the 
physical presence of a nearby vessel, may be more relevant to the 
animal's response than the received level alone.
    Controlled experiments with captive marine mammals have shown 
pronounced behavioral reactions, including avoidance of loud underwater 
sound sources (Ridgway et al. 1997; Finneran et al. 2003). Observed 
responses of wild marine mammals to loud pulsed sound sources 
(typically seismic guns or acoustic harassment devices) have been 
varied but often consist of avoidance behavior or other behavioral 
changes suggesting discomfort (Morton and Symonds 2002; Thorson and 
Reyff 2006; see also Gordon et al., 2004; Nowacek et al. 2007).
    The onset of noise can result in temporary, short-term changes in 
an animal's typical behavior and/or avoidance of the affected area. 
These behavioral changes may include: reduced/increased vocal 
activities; changing/cessation of certain behavioral activities (such 
as socializing or feeding); visible startle response or aggressive 
behavior; avoidance of areas where sound sources are located; and/or 
flight responses (Richardson et al. 1995).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could potentially be biologically significant if the 
change affects growth, survival, or reproduction. The onset of 
behavioral disturbance from anthropogenic sound depends on both 
external factors (characteristics of sound sources and their paths) and 
the specific characteristics of the receiving animals (hearing, 
motivation, experience, demography) and is difficult to predict 
(Southall et al. 2007).
    Ellison et al. (2011) 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,

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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 proposed 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.
    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. 
(2016) conducted a review of the literature considering the contextual 
information of exposure in addition to received level and found that 
higher received levels were not always associated with more severe 
behavioral responses and vice versa. Southall et al. (2016) states that 
results demonstrate that some individuals of different species display 
clear yet varied responses, some of which have negative implications, 
while others appear to tolerate high levels, and that responses may not 
be fully predictable with simple acoustic exposure metrics (e.g., 
received sound level). Rather, the authors state that differences among 
species and individuals along with contextual aspects of exposure 
(e.g., behavioral state) appear to affect response probability.
    During an activity with a series of explosions (not concurrent 
multiple explosions shown in a burst), an animal is expected to exhibit 
a startle reaction to the sound of the first detonation followed by 
another behavioral response after multiple detonations. At close ranges 
and high sound levels, avoidance of the area around the explosions is 
the assumed behavioral response in most cases. In certain 
circumstances, exposure to loud sounds can interrupt feeding behaviors 
and potentially decrease foraging success, interfere with communication 
or migration, or disrupt important reproductive or young-rearing 
behaviors, among other effects.
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Behavioral 
reactions to noise exposure (such as disruption of critical life 
functions, displacement, or avoidance of important habitat) are more 
likely to be significant for fitness if they last more than one diel 
cycle or recur on subsequent days (Southall et al. 2007). Consequently, 
a behavioral response lasting less than one day and not recurring on 
subsequent days is not considered particularly severe unless it could 
directly affect reproduction or survival (Southall et al. 2007). It is 
important to note the difference between behavioral reactions lasting 
or recurring over multiple days and anthropogenic activities lasting or 
recurring over multiple days. For example, just because a given 
anthropogenic activity lasts for multiple days (e.g., a training event) 
does not necessarily mean that individual animals will be either 
exposed to those activity-related stressors (i.e., explosions) for 
multiple days or further exposed at a level would result in sustained 
multi-day substantive behavioral responses.

Auditory Masking

    Sound can disrupt behavior through masking, or interfering with, an 
animal's ability to detect, recognize, or discriminate between acoustic 
signals of interest (e.g., those used for intraspecific communication 
and social interactions, prey detection, predator avoidance, or 
navigation) (Richardson et al. 1995; Erbe and Farmer 2000; Tyack 2000; 
Erbe et al. 2016). Masking occurs when the receipt of a sound is 
interfered with by another coincident sound at similar frequencies and 
at similar or higher intensity, and may occur whether the sound is 
natural (e.g., snapping shrimp, wind, waves, precipitation) or 
anthropogenic (e.g., shipping, sonar, seismic exploration) in origin. 
The ability of a noise source to mask biologically important sounds 
depends on the characteristics of both the noise source and the signal 
of interest (e.g., signal-to-noise ratio, temporal variability, 
direction), in relation to each other and to an animal's hearing 
abilities (e.g., sensitivity, frequency range, critical ratios, 
frequency discrimination, directional discrimination, age, or TTS 
hearing loss), and existing ambient noise and propagation conditions. 
Masking these acoustic signals can disturb the behavior of individual 
animals, groups of animals, or entire populations. Masking can lead to 
behavioral changes including vocal changes (e.g., Lombard effect, 
increasing amplitude, or changing frequency), cessation of foraging, 
and leaving an area, to both signalers and receivers, in an attempt to 
compensate for noise levels (Erbe et al. 2016). Masking only occurs in 
the presence of the masking noise and does not persist after the 
cessation of the noise. Masking may lead to a change in vocalizations 
or a change in behavior (e.g., cessation of foraging, leaving an area). 
Masking by explosive detonation sounds would not be expected, given the 
short duration, and there are no direct observations of masking in 
marine mammals due to exposure to sound from explosive detonations.

Physiological Stress

    There is growing interest in monitoring and assessing the impacts 
of stress responses to sound in marine animals. Classic stress 
responses begin when an animal's central nervous system perceives a 
potential threat to its homeostasis. That perception triggers stress 
responses regardless of whether a stimulus actually threatens the 
animal; the mere perception of a threat is sufficient to trigger a 
stress response (Moberg 2000; Sapolsky et al. 2005; Seyle 1950). Once 
an animal's central nervous system perceives a threat, it mounts a 
biological response or defense that consists of a combination of the 
four general biological defense responses: behavioral responses, 
autonomic nervous system responses, neuroendocrine responses, or immune 
responses.
    According to Moberg (2000), in the case of many stressors, an 
animal's first and sometimes most economical (in terms of biotic costs) 
response is behavioral avoidance of the potential stressor or avoidance 
of continued exposure to a stressor. An animal's second line of defense 
to stressors involves the sympathetic part of the autonomic nervous 
system and the classical ``fight or flight'' response which includes 
the cardiovascular system, the gastrointestinal system, the exocrine 
glands, and the adrenal medulla to produce changes in heart rate, blood 
pressure, and gastrointestinal activity that humans commonly

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associate with ``stress.'' These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's welfare.
    An animal's third line of defense to stressors involves its 
neuroendocrine systems or sympathetic nervous systems; the system that 
has received the most study has been the hypothalamus-pituitary-adrenal 
system (also known as the HPA axis in mammals or the hypothalamus-
pituitary-interrenal axis in fish and some reptiles). Unlike stress 
responses associated with the autonomic nervous system, virtually all 
neuro-endocrine functions that are affected by stress--including immune 
competence, reproduction, metabolism, and behavior--are regulated by 
pituitary hormones. Stress-induced changes in the secretion of 
pituitary hormones have been implicated in failed reproduction (Moberg, 
1987; Rivier and Rivest 1991), altered metabolism (Elasser et al. 
2000), reduced immune competence (Blecha 2000), and behavioral 
disturbance (Moberg 1987; Blecha 2000). Increases in the circulation of 
glucocorticosteroids (cortisol, corticosterone, and aldosterone in 
marine mammals; see Romano et al. 2004) have been equated with stress 
for many years.
    Because there are many unknowns regarding the occurrence of 
acoustically induced stress responses in marine mammals, it is assumed 
that any physiological response (e.g., hearing loss or injury) or 
significant behavioral response is also associated with a stress 
response.

Munition Strike

    Another potential risk to marine mammals is direct strike by 
ordnance, in which the ordnance physically hits an animal. Based on the 
dispersed distribution of marine mammals in the open ocean, the 
relatively short amount of time they spend at the water surface 
compared with the time they spend underwater, and the annual quantities 
of munitions proposed to be expended, it is highly improbable that a 
marine mammal would be directly struck by a munition during EGTTR 
operations. This conclusion, which NMFS concurs with, was reached in 
the previous 2015 REA (USAF 2015). The Air Force did not request take 
of marine mammals by direct munition strikes, as it is not anticipated, 
and it is not analyzed further.

Marine Mammal Habitat

    Impacts on marine mammal habitat are part of the consideration in 
making a finding of negligible impact on the species and stocks of 
marine mammals. Habitat includes, but is not necessarily limited to, 
rookeries, mating grounds, feeding areas, and areas of similar 
significance. We have preliminarily determined USAF's proposed 
activities would not result in permanent effects on the habitats used 
by the marine mammals in the EGTTR, including the availability of prey 
(i.e. fish and invertebrates). While it is anticipated that the 
proposed activity may result in marine mammals avoiding certain areas 
due to temporary ensonification, any impact to habitat is temporary and 
reversible and was considered in further detail earlier in this 
document, as behavioral modification. The main impact associated with 
the proposed activity will be temporarily elevated noise levels and the 
associated direct effects on marine mammals, previously discussed in 
this proposed rule.
    Sound may affect marine mammals through impacts on the abundance, 
behavior, or distribution of prey species (e.g., crustaceans, 
cephalopods, fish, zooplankton). Marine mammal prey varies by species, 
season, and location and, for some species, is not well documented. 
Here, we describe studies regarding the effects of noise on known 
marine mammal prey.
    Effects on Fish--Fish utilize the soundscape and components of 
sound in their environment to perform important functions such as 
foraging, predator avoidance, mating, and spawning (e.g., Zelick et al. 
1999; Fay 2009). The most likely effects on fishes exposed to loud, 
intermittent, low-frequency sounds are behavioral responses (i.e., 
flight or avoidance). Short duration, sharp sounds (such as pile 
driving or air guns) can cause overt or subtle changes in fish behavior 
and local distribution. The reaction of fish to acoustic sources 
depends on the physiological state of the fish, past exposures, 
motivation (e.g., feeding, spawning, migration), and other 
environmental factors. Key impacts to fishes may include behavioral 
responses, hearing damage, barotrauma (pressure-related injuries), and 
mortality.
    Fishes, like other vertebrates, have a variety of different sensory 
systems to glean information from ocean around them (Astrup and Mohl 
1993; Astrup 1999; Braun and Grande 2008; Carroll et al. 2017; Hawkins 
and Johnstone 1978; Ladich and Popper 2004; Ladich and Schulz-Mirbach 
2016; Nedwell et al. 2004; Popper et al. 2003; Popper et al. 2005). 
Depending on their hearing anatomy and peripheral sensory structures, 
which vary among species, fishes hear sounds using pressure and 
particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al. 2008) (terrestrial vertebrates generally 
only detect pressure). Most marine fishes primarily detect particle 
motion using the inner ear and lateral line system, while some fishes 
possess additional morphological adaptations or specializations that 
can enhance their sensitivity to sound pressure, such as a gas-filled 
swim bladder (Braun and Grande 2008; Popper and Fay 2011).
    Hearing capabilities vary considerably between different fish 
species with data only available for just over 100 species out of the 
34,000 marine and freshwater fish species (Eschmeyer and Fong 2016). In 
order to better understand acoustic impacts on fishes, fish hearing 
groups are defined by species that possess a similar continuum of 
anatomical features which result in varying degrees of hearing 
sensitivity (Popper and Hastings 2009a). There are four hearing groups 
defined for all fish species (modified from Popper et al. 2014) within 
this analysis and they include: fishes without a swim bladder (e.g., 
flatfish, sharks, rays, etc.); fishes with a swim bladder not involved 
in hearing (e.g., salmon, cod, pollock, etc.); fishes with a swim 
bladder involved in hearing (e.g., sardines, anchovy, herring, etc.); 
and fishes with a swim bladder involved in hearing and high-frequency 
hearing (e.g., shad and menhaden). Currently, less data are available 
to estimate the range of best sensitivity for fishes without a swim 
bladder.
    In terms of behavioral responses of fish, Juanes et al. (2017) 
discuss the potential for negative impacts from anthropogenic 
soundscapes on fish, but the authors' focus was on broader based 
sounds, such as ship and boat noise sources. Occasional behavioral 
reactions to intermittent explosions occurring at or near the surface 
are unlikely to cause long-term consequences for individual fish or 
populations; there are no detonations of explosives occurring 
underwater from the proposed activities. Fish that experience hearing 
loss as a result of exposure to explosions may have a reduced ability 
to detect relevant sounds, such as predators, prey, or social 
vocalizations. However, PTS has not been known to occur in fishes and 
any hearing loss in fish may be as temporary as the timeframe required 
to repair or replace the sensory cells that were damaged or destroyed 
(Popper et al. 2005; Popper et al. 2014; Smith et al. 2006). It is not 
known if damage to auditory nerve fibers could occur, and if so, 
whether fibers would recover during this process. It is also possible 
for fish to be injured or killed by an explosion in the immediate

[[Page 8168]]

vicinity of the surface from dropped or fired ordnance. Physical 
effects from pressure waves generated by detonations at or near the 
surface could potentially affect fish within proximity of training or 
testing activities. The shock wave from an explosion occurring at or 
near the surface may be lethal to fish at close range, causing massive 
organ and tissue damage and internal bleeding (Keevin and Hempen, 
1997). At greater distance from the detonation point, the extent of 
mortality or injury depends on a number of factors including fish size, 
body shape, orientation, and species (Keevin and Hempen, 1997; Wright, 
1982). At the same distance from the source, larger fish are generally 
less susceptible to death or injury, elongated forms that are round in 
cross-section are less at risk than deep-bodied forms, and fish 
oriented sideways to the blast suffer the greatest impact (Edds-Walton 
and Finneran 2006; Wiley et al. 1981; Yelverton et al. 1975). Species 
with gas-filled organs are more susceptible to injury and mortality 
than those without them (Gaspin, 1975; Gaspin et al. 1976; Goertner et 
al. 1994).
    Training and testing exercises involving explosions at or near the 
surface are dispersed in space and time; therefore, repeated exposure 
of individual fishes are unlikely. Mortality and injury effects to 
fishes from explosives would be localized around the area of a given 
explosion at or above the water surface, but only if individual fish 
and the explosive at the surface were co-located at the same time. 
Fishes deeper in the water column or on the bottom would not be 
affected by surface explosions. Most acoustic effects, if any, are 
expected to be short term and localized. Long-term consequences for 
fish populations, including key prey species within the EGTTR Area, 
would not be expected.
    Effects on Invertebrates--In addition to fish, prey sources such as 
marine invertebrates could potentially be impacted by sound stressors 
as a result of the proposed activities. However, most marine 
invertebrates' ability to sense sounds is very limited. In most cases, 
marine invertebrates would not respond to impulsive sounds. Data on 
response of invertebrates such as squid, another marine mammal prey 
species, to anthropogenic sound has been documented (de Soto 2016; Sole 
et al. 2017). Explosions could kill or injure nearby marine 
invertebrates. Vessels also have the potential to impact marine 
invertebrates by disturbing the water column or sediments, or directly 
striking organisms (Bishop 2008). The propeller wash (water displaced 
by propellers used for propulsion) from vessel movement and water 
displaced from vessel hulls can potentially disturb marine 
invertebrates in the water column and are a likely cause of zooplankton 
mortality (Bickel et al. 2011). The localized and short-term exposure 
to explosions or vessels at or near the surface could displace, injure, 
or kill zooplankton, invertebrate eggs or larvae, and macro-
invertebrates. However, mortality or long-term consequences for a few 
animals is unlikely to have measurable effects on overall populations. 
As with fish, cumulatively individual and population-level impacts from 
exposure to explosives at or above the water surface are not 
anticipated, and impacts would be short term and localized, and would 
likely be inconsequential to invertebrate populations, and to the 
marine mammals that use them as prey.
    Expended Materials--Military expended materials resulting from 
training and testing activities could potentially result in minor long-
term changes to benthic habitat, however the impacts of small amounts 
of expended materials are unlikely to have measurable effects on 
overall populations. Military expended materials may be colonized over 
time by benthic organisms that prefer hard substrate and would provide 
structure that could attract some species of fish or invertebrates.
    Overall, the combined impacts of explosions and military expended 
materials resulting from the proposed activities would not be expected 
to have measurable effects on populations of marine mammal prey 
species. Prey species exposed to sound might move away from the sound 
source or show no obvious direct effects at all, but a rapid return to 
normal recruitment, distribution, and behavior is anticipated. Long-
term consequences to fish or marine invertebrate populations would not 
be expected as a result of exposure to sounds or vessels in the EGTTR.
    Acoustic Habitat--Acoustic habitat is the soundscape which 
encompasses all of the sound present in a particular location and time, 
as a whole, when considered from the perspective of the animals 
experiencing it. Animals produce sound for, or listen for sounds 
produced by, conspecifics (communication during feeding, mating, and 
other social activities), other animals (finding prey or avoiding 
predators), and the physical environment (finding suitable habitats, 
navigating). Together, sounds made by animals and the geophysical 
environment (e.g., produced by earthquakes, lightning, wind, rain, 
waves) make up the natural contributions to the total acoustics of a 
place. These acoustic conditions, termed acoustic habitat, are one 
attribute of an animal's total habitat.
    Soundscapes are also defined by, and acoustic habitat influenced 
by, the total contribution of anthropogenic sound. This may include 
incidental emissions from sources, such as vessel traffic or may be 
intentionally introduced to the marine environment for data acquisition 
purposes (e.g., as in the use of air gun arrays) or USAF training and 
testing purposes (as in the use of explosives). Anthropogenic noise 
varies widely in its frequency, content, duration, and loudness, and 
these characteristics greatly influence the potential habitat-mediated 
effects to marine mammals, which may range from local effects for brief 
periods of time to chronic effects over large areas and for long 
durations. Depending on the extent of effects to habitat, animals may 
alter their communications signals (thereby potentially expending 
additional energy) or miss acoustic cues (either conspecific or 
adventitious). Problems arising from a failure to detect cues are more 
likely to occur when noise stimuli are chronic and overlap with 
biologically relevant cues used for communication, orientation, and 
predator/prey detection (Francis and Barber, 2013). For more detail on 
these concepts see Pijanowski et al. 2011; Francis and Barber 2013; 
Lillis et al. 2014. We do not anticipate these problems arising from at 
or near surface explosions during training and testing activities as 
they would be either widely dispersed or concentrated in small areas 
for shorter periods of time. Sound produced from training and testing 
activities in the EGTTR would be temporary and transitory; the affected 
area would be expected to immediately return to the original state when 
these activities cease.
    Marine Water Quality--Training and testing activities may introduce 
water quality constituents into the water column. Metals are the 
dominant constituent by weight of bombs, missiles, gun ammunition, and 
other munitions, including inert munitions, used during EGTTR training 
and testing operations. Some targets used during EGTTR missions also 
contain metals, including CONEX and hopper barge targets used for PSW 
tests and certain components of remotely controlled target boats. 
Metals contained in casing fragments of detonated munitions, intact 
inert munitions, unexploded ordnance, and other mission-related debris 
will corrode from exposure to seawater. The

[[Page 8169]]

rate of corrosion depends on the metal type and the extent to which the 
item is directly exposed to seawater, which can be influenced by 
existing corrosion on the item, and how much the item may be encrusted 
by marine organisms and/or buried in sediments. Aluminum and steel, 
which is composed mostly of iron, comprise the bulk of the metal that 
enters the marine environment from EGTTR operations. Iron and aluminum 
are relatively benign metals in terms of toxicity. Chromium, lead, and 
copper, which make up a relatively small percentage of the overall 
metal input into the marine environment from EGTTR operations, have 
higher toxicity effects. Through its lifetime in the marine 
environment, a portion of the overall metal content would dissolve, 
depending on the solubility of the material. Dissolved metals would 
readily undergo mixing and dilution and would have no appreciable 
effect on water quality or marine life within the water column. Metals 
in particulate form would be released into sediments through the 
corrosion process. Elevated levels of undissolved metals in sediments 
would be restricted to a relatively small area around the metal-
containing item and any associated impacts to water quality would be 
negligible.
    Munitions used for EGTTR training and testing operations contain a 
wide variety of explosives, including TNT, RDX, HMX, Composition B, 
Tritonal, AFX-757, PBXN, and others. During live missions in the EGTTR, 
explosives can enter the marine environment via high-order detonations, 
which occur when the munition functions as intended and the vast 
majority of explosives are consumed; low-order detonations, which occur 
when the munition partially functions and only a portion of the 
explosives are consumed; and unexploded munitions, which fail to 
detonate with no explosives consumed. During high-order detonations, a 
residual amount of the explosive material, typically less than 1 
percent, would be unconsumed and released into the environment (Walsh 
et al. 2011). The majority of live munitions used during EGTTR 
operations are successfully detonated as intended. During low-order 
detonations, a residual amount of explosives associated with the 
detonation and the remaining unconsumed portion of the explosive fill 
would enter the marine environment. If the munition does not explode, 
it becomes unexploded ordnance (UXO). In this case, all the explosive 
material would remain within the munition casing and enter the marine 
environment with explosives potentially being released due to corrosion 
or rupture. Explosives and explosives by-products released into the 
marine environment can be removed via biodegradation, and expended or 
disposed military munitions on the seafloor do not result in excessive 
accumulation of explosives in sediments or significant degradation of 
sediment quality by explosives. Given that high-order detonations 
consume the vast majority of explosive material in the munition, 
successful detonations are considered a negligible source of explosives 
released into the marine environment.

Estimated Take of Marine Mammals

    This section indicates the number of takes that NMFS is proposing 
to authorize, which is based on the maximum amount that is reasonably 
likely to occur, depending on the type of take and the methods used to 
estimate it, as described in detail below. NMFS preliminarily agrees 
that the methods the USAF has put forth described herein to estimate 
take (including the model, thresholds, and density estimates), and the 
resulting numbers estimated for authorization, are appropriate and 
based on the best available science.
    All takes are by harassment. For a military readiness activity, the 
MMPA defines ``harassment'' as (i) Any act that injures or has the 
significant potential to injure a marine mammal or marine mammal stock 
in the wild (Level A Harassment); or (ii) Any act that disturbs or is 
likely to disturb a marine mammal or marine mammal stock in the wild by 
causing disruption of natural behavioral patterns, including, but not 
limited to, migration, surfacing, nursing, breeding, feeding, or 
sheltering, to a point where such behavioral patterns are abandoned or 
significantly altered (Level B Harassment). No serious injury or 
mortality of marine mammals is expected to occur.
    Proposed authorized takes would primarily be in the form of Level B 
harassment, as use of the explosive sources may result, either directly 
or as result of TTS, in the disruption of natural behavioral patterns 
to a point where they are abandoned or significantly altered (as 
defined specifically at the beginning of this section, but referred to 
generally as behavioral disruption). There is also the potential for 
Level A harassment, in the form of auditory injury to result from 
exposure to the sound sources utilized in training and testing 
activities. As described in this Estimated Take of Marine Mammals 
section, no non-auditory injury is anticipated or proposed for 
authorization, nor is any serious injury or mortality.
    Generally speaking, for acoustic impacts NMFS estimates the amount 
and type of harassment by considering: (1) acoustic thresholds above 
which NMFS believes the best available science indicates marine mammals 
will be taken by Level B harassment or incur some degree of temporary 
or permanent hearing impairment; (2) the area or volume of water that 
will be ensonified above these levels in a day or event; (3) the 
density or occurrence of marine mammals within these ensonified areas; 
and (4) the number of days of activities or events. This analysis of 
the potential impacts of the proposed activities on marine mammals was 
conducted by using the spatial density models developed by NOAA's 
Southeast Fisheries Science Center for the species in the Gulf of 
Mexico (NOAA 2022). The density model integrated visual observations 
from aerial and shipboard surveys conducted in the Gulf of Mexico from 
2003 to 2019.
    The munitions proposed to be used by each military unit were 
grouped into mission-day categories so the acoustic impact analysis 
could be based on the total number of detonations conducted during a 
given mission to account for the accumulated energy from multiple 
detonations over a 24-hour period. A total of 19 mission-day categories 
were developed for the munitions proposed to be used. Using the dBSea 
underwater acoustic model and associated analyses, the threshold 
distances associated with Level A harassment (PTS) and Level B (TTS and 
behavioral) harassment zones were estimated for each mission-day 
category for each marine mammal species. Takes were estimated based on 
the area of the harassment zones, predicted animal density, and annual 
number of events for each mission-day category. To assess the potential 
impacts of inert munitions on marine mammals, the proposed inert 
munitions were categorized into four classes based on their impact 
energies, and the threshold distances for each class were modeled and 
calculated as described for the mission-day categories.

Acoustic Thresholds

    Using the best available science, NMFS has established acoustic 
thresholds that identify the most appropriate received level of 
underwater sound above which marine mammals exposed to these sound 
sources could be reasonably expected to directly experience a 
disruption in behavior patterns to a point where they are abandoned or 
significantly altered,

[[Page 8170]]

to incur TTS (equated to Level B harassment), or to incur PTS of some 
degree (equated to Level A harassment). Thresholds have also been 
developed to identify the pressure levels above which animals may incur 
non-auditory injury from exposure to pressure waves from explosive 
detonation. Refer to the Criteria and Thresholds for U.S. Navy Acoustic 
and Explosive Effects Analysis (Phase III) report (U.S. Department of 
the Navy 2017c) for detailed information on how the criteria and 
thresholds were derived.
Hearing Impairment (TTS/PTS), Tissues Damage, and Mortality
    NMFS' Acoustic Technical Guidance (NMFS 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). The Acoustic Technical Guidance also 
identifies criteria to predict TTS, which is not considered injury and 
falls into the Level B harassment category. The USAF's proposed 
activity only includes the use of impulsive (explosives) sources. These 
thresholds (Table 20) were developed by compiling and synthesizing the 
best available science and soliciting input multiple times from both 
the public and peer reviewers. The references, analysis, and 
methodology used in the development of the thresholds are described in 
Acoustic Technical Guidance, which may be accessed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
    Additionally, based on the best available science, NMFS uses the 
acoustic and pressure thresholds indicated in Table 20 to predict the 
onset of TTS, PTS, tissue damage, and mortality for explosives 
(impulsive) and other impulsive sound sources.

           Table 20--Onset of TTS, PTS, Tissue Damage, and Mortality Thresholds for Marine Mammals for Explosives and Other Impulsive Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                         Mean onset
    Functional hearing group            Species             Onset TTS            Onset PTS        Mean onset slight      slight lung       Mean onset
                                                                                                   GI tract injury         injury           mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans.........  Rice's whale.......  168 dB SEL           183 dB SEL           237 dB Peak SPL....  Equation 1        Equation 2
                                                        (weighted) or 213    (weighted) or 219
                                                        dB Peak SPL.         dB Peak SPL.
Mid-frequency cetaceans.........  Dolphins...........  170 dB SEL           185 dB SEL           237 dB Peak SPL....
                                                        (weighted) or 224    (weighted) or 230
                                                        dB Peak SPL.         dB Peak SPL.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes: Equation 1: 47.5M\1/3\ (1+[DRm/10.1])\1/6\ Pa-sec. Equation 2: 103M\1/3\ (1+[DRm/10.1])\1/6\ Pa-sec. M = mass of the animals in kg; DRm = depth
  of the receiver (animal) in meters; SPL = sound pressure level.

    Refer to the Criteria and Thresholds for U.S. Navy Acoustic and 
Explosive Effects Analysis (Phase III) report (U.S. Department of the 
Navy, 2017c) for detailed information on how the criteria and 
thresholds were derived. Non-auditory injury (i.e., other than PTS) and 
mortality are so unlikely as to be discountable under normal conditions 
and are therefore not considered further in this analysis.
Behavioral Disturbance
    Though significantly driven by received level, the onset of Level B 
harassment by direct behavioral disturbance from anthropogenic noise 
exposure is also informed to varying degrees by other factors related 
to the source (e.g., frequency, predictability, duty cycle, distance), 
the environment (e.g., bathymetry), and the receiving animals (hearing, 
motivation, experience, demography, behavioral context) and can be 
difficult to predict (Ellison et al. 2011; Southall et al. 2007). Based 
on what the available science indicates and the practical need to use 
thresholds based on a factor or factors that are both predictable and 
measurable for most activities, NMFS uses generalized acoustic 
thresholds based primarily on received level (and distance in some 
cases) to estimate the onset of Level B harassment by behavioral 
disturbance.
    Explosives--Explosive thresholds for Level B harassment by 
behavioral disturbance for marine mammals are the hearing groups' TTS 
thresholds minus 5 dB (see Table 21 below for the TTS thresholds for 
explosives) for events that contain multiple impulses from explosives 
underwater. See the Criteria and Thresholds for U.S. Navy Acoustic and 
Explosive Effects Analysis (Phase III) report (U.S. Department of the 
Navy 2017c) for detailed information on how the criteria and thresholds 
were derived. NMFS continues to concur that this approach represents 
the best available science for determining behavioral disturbance of 
marine mammals from multiple explosives. While marine mammals may also 
respond to single explosive detonations, these responses are expected 
to more typically be in the form of startle reaction, rather than a 
disruption in natural behavioral patterns to the point where they are 
abandoned or significantly altered. On the rare occasion that a single 
detonation might result in a more severe behavioral response that 
qualifies as Level B harassment, it would be expected to be in response 
to a comparatively higher received level. Accordingly, NMFS considers 
the potential for these responses to be quantitatively accounted for 
through the application of the TTS threshold, which, as noted above, is 
5 dB higher than the behavioral harassment threshold for multiple 
explosives.

  Table 21--Thresholds for Level B Harassment by Behavioral Disturbance
                    for Explosives for Marine Mammals
------------------------------------------------------------------------
                                                                 SEL
            Medium               Functional hearing group     (weighted)
------------------------------------------------------------------------
Underwater...................  LF                                    163
Underwater...................  MF                                    165
------------------------------------------------------------------------
Note: Weighted SEL thresholds in dB re 1 [mu]Pa\2\s underwater. LF = low-
  frequency, MF = mid-frequency, HF = high-frequency.

USAF's Acoustic Effects Model

    The USAF's Acoustic Effects Model calculates sound energy 
propagation from explosives during UASF activities in the EGTTR. The 
net explosive weight (NEW) of a munition at impact can be directly 
correlated with the energy in the impulsive pressure wave generated by 
the warhead detonation. The NEWs of munitions addressed as part of this 
proposed rule range from 0.1 lb (0.04 kg) for small projectiles to 945 
lb (428.5kg) for the largest bombs. The explosive materials used in 
these munitions also vary considerably with different formulations used 
to produce different intended effects. The primary detonation metrics 
directly considered and used for modeling analysis are the peak impulse 
pressure and duration of the impulse. An integration of the

[[Page 8171]]

pressure of an impulse over the duration (time) of an impulse provides 
a measure of the energy in an impulse. Some of the NEWs of certain 
types of munitions, such as missiles, are associated with the 
propellant used for the flight of the munition. This propellant NEW is 
unrelated to the NEW of the warhead, which is the primary source of 
explosive energy in most munitions. The propellant of a missile fuels 
the flight phase and is mostly consumed prior to impact. Missile 
propellant typically has a lower flame speed than warhead explosives 
and is relatively insensitive to detonation from impacts but burns 
readily. A warhead detonation provides a high-pressure, high-velocity 
flame front that may cause burning propellant to detonate; therefore, 
this analysis assumes that the unconsumed residual propellant that 
remains at impact contributes to the detonation-induced pressure 
impulse in the water. The impact analysis assumes that 20 percent of 
the propellant remains unconsumed in missiles at impact; this 
assumption is based on input from user groups and is considered a 
reasonable estimate for the purpose of analysis. The NEW associated 
with this unconsumed propellant is added to the NEW of the warhead to 
derive the total energy released by the detonation. Absent a warhead 
detonation, it is assumed that continued burning or deflagration of 
unconsumed residual propellant does not contribute to the pressure 
impulse in the water; this applies to inert missiles that lack a 
warhead but contain propellant for flight.
    In addition to the energy associated with the detonation, energy is 
also released by the physical impact of the munition with the water. 
This kinetic energy has been calculated and incorporated into the 
estimations of munitions energy for both live and inert munitions in 
this proposed rule. The kinetic energy of the munition at impact is 
calculated as one half of the munition mass times the square of the 
munition velocity. The initial impact event contributing to the 
pressure impulse in water is assumed to be 1 millisecond in duration. 
To calculate the velocity (and kinetic energy) immediately after 
impact, the deceleration contributing to the pressure impulse in the 
water is assumed for all munitions to be 1,500 g-forces, or 48,300 feet 
per square second over 1 millisecond. A substantial portion of the 
change in kinetic energy at impact is dissipated as a pressure impulse 
in the water, with the remainder being dissipated through structural 
deformation of the munition, heat, displacement of water, and other 
smaller energy categories. Even with 1,500 g-forces of deceleration, 
the change in velocity over this short time period is small and is 
proportional to the impact velocity and munition mass. The impact 
energy is the portion of the kinetic energy at impact that is 
transmitted as an underwater pressure impulse, expressed in units of 
trinitrotoluene-equivalent (TNTeq). The impact energies of the proposed 
live munitions were calculated and included in their total energy 
estimations. The impact energies of the inert munitions proposed to be 
used were also calculated. To assess the potential impacts of inert 
munitions on marine animals, the inert munitions were categorized based 
on their impact energies into the following four classes of 2 lb (0.9 
kg), 1 lb (0.45 kg), 0.5 lb (0.22 kg), and 0.15 lb (0.07 kg) TNTeq; 
these values correspond closely to the actual or average impact energy 
values of the munitions and are rounded for the purpose of analysis. 
The 2 lb class represents the largest inert bomb, which includes the 
Mark (Mk)-84 General Purpose (GP), Guided Bomb Unit (GBU)-10, and GBU-
31 bombs, whereas the 1 lb class represents the largest inert missile, 
which is the Air-to-Ground Missile (AGM)-158 Joint Air-to-Surface 
Standoff Missile (JASSM). The JASSM has greater mass but lower impact 
energy than the GBU-31; this is because of the JASSM's lower velocity 
at impact and associated change in velocity over the deceleration 
period, which contributes to the pressure impulse. The 0.5 lb and 0.15 
lb impact energy classes each represent the approximate average impact 
energy of multiple munitions, with the 0.5 lb class representing 
munitions with mid-level energies, and the 0.15 lb class representing 
munitions with the lowest energies (Table 22).

                          Table 22--Impact Energy Classes for Proposed Inert Munitions
----------------------------------------------------------------------------------------------------------------
Impact energy class  (lb TNTeq)/                            Approximate weight  (lb)/    Approximate velocity
              (kg)                Representative munitions            (kg)                      (mach)
----------------------------------------------------------------------------------------------------------------
2 (0.9).........................  Mk-84, GBU-10, and GBU-   2,000 (907).............  1.1.
                                   31.
1 (0.45)........................  AGM-158 JASSM...........  2,250 (1020.3)..........  0.9.
0.5 (0.22)......................  GBU-54 and AIM-120......  250 to 650 (113.4 to      Variable.
                                                             294.8).
0.15 (0.07).....................  AIM-9, GBU-39, and PGU-   1 to 285 (0.5 to 129.2).  Variable.
                                   15.
----------------------------------------------------------------------------------------------------------------

    The NEW associated with the physical impact of each munition and 
the unconsumed propellant in certain munitions is added to the NEW of 
the warhead to derive the NEW at impact (NEWi) for each live munition. 
The NEWi of each munition was then used to calculate the peak pressure 
and pressure decay for each munition. This results in a more accurate 
estimate of the actual energy released by each detonation. Extensive 
research since the 1940s has shown that each explosive formulation 
produces unique correlations to explosive performance metrics. The peak 
pressure and pressure decay constant depend on the NEW, explosive 
formulation, and distance from the detonation. The peak pressure and 
duration of the impulse for each munition can be calculated empirically 
using similitude equations, with constants used in these equations 
determined from experimental data (NSWC 2017). The explosive-specific 
similitude constants and munition-specific NEWi were used for 
calculating the peak pressure and pressure decay for each munition 
analyzed. It should be noted that this analysis assumes that all 
detonations occur in the water and none of the detonations occur above 
the water surface when a munition impacts a target. This exceptionally 
conservative assumption implies that all munition energy is imparted to 
the water rather than the intended targets. See Appendix A in the LOA 
application for detailed explanations of similitude equations.
    The following standard metrics are used to assess underwater 
pressure and impulsive noise impacts on marine animals:
     SPL: The SPL for a given munition can be explicitly 
calculated at a radial distance using the similitude equations.
     SEL: A commercially available software package, dBSea 
(version 2.3), was used to calculate the SEL for each mission day.
     Positive Impulse: This is the time integral of the initial 
positive phase of

[[Page 8172]]

the pressure impulse. This metric provides a measure of energy in the 
form of time-integrated pressure. Units are typically pascal-seconds 
(Pa[middot]s) or pounds per square inch (psi) per millisecond (msec) 
(psi[middot]msec). The positive impulse for a given munition can be 
explicitly calculated at a given distance using the similitude 
equations and integrating the pressure over the initial positive phase 
of the pressure impulse.
    The munition-specific peak pressure and pressure decay at various 
radii were used to determine the species-specific distance to effect 
threshold for mortality, non-auditory injury, peak pressure-induced 
permanent threshold shift (PTS) in hearing and peak pressure-induced 
temporary threshold shift (TTS) in hearing for each species. The 
munition-specific peak pressures and decays for all munitions in each 
mission-day category were used as a time-series input in the dBSea 
underwater acoustic model to determine the distance to effect for 
cumulative SEL-based (24-hour) PTS, TTS, and behavioral effects for 
each species for each mission day.
    The dBSea model was conducted using a constant sound speed profile 
(SSP) of 1500 m/s to be both representative of local conditions and to 
prevent thermocline induced refractions from distorting the analysis 
results. Salinity was assumed to be 35 parts per thousand (ppt) and pH 
was 8. The water surface was treated as smooth (no waves) to 
conservatively eliminate diffraction induced attenuation of sound. 
Currents and tidal flow were treated as zero. Energy expended on the 
target and/or on ejecting water or transfer into air was ignored and 
all weapon energy was treated as going into underwater acoustic energy 
to be conservative. Finally, the bottom was treated as sand with a 
sound speed of 1650 m/s and an attenuation of 0.8 dB/wavelength.
    The harassment zone is the area or volume of ocean in which marine 
animals could be exposed to various pressure and impulsive noise levels 
generated by a surface or subsurface detonation that would result in 
mortality; non-auditory injury and PTS (Level A harassment impacts); 
and TTS and behavioral impacts (Level B harassment impacts). The 
harassment zones for the proposed detonations were estimated using 
Version 2.3 of the dBSea model for cumulative SEL and using explicit 
similitude equations for SPL and positive impulse. The characteristics 
of the impulse noise at the source were calculated based on munition-
specific data including munition mass at impact, munition velocity at 
impact, NEW of warheads, explosive-specific similitude data, and 
propellant data for missiles. Table 23 presents the source-level SPLs 
(at r = 1 meter) calculated for the proposed munitions.

                                                     Table 23--Calculated Source SPLs for Munitions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                  Peak pressure and decay values
                                            Warhead NEW                                     Model NEWi   -----------------------------------------------
                  Type                       (lb)/(kg)          Modeled  explosive           (lm)/(kg)       Pmax @1 m    SPL @1 m dB re
                                                                                                               (psi)           1 mPa       [Theta] msec
--------------------------------------------------------------------------------------------------------------------------------------------------------
AGM-158 JASSM All Variants..............  240.26 (108.9)  Tritonal......................  241.36 (109.5)      45961.4858           290.0           0.320
GBU-54 KMU-572C/B, B/B..................      192 (87.1)  Tritonal......................    192.3 (87.2)      42101.8577           289.3           0.302
AGM-65 (all variants)...................       85 (38.5)  Comp B........................     98.3 (44.6)      37835.4932           288.3           0.200
AIM-120C3...............................        15 (6.8)  PBXN-110......................    36.18 (13.4)       24704.864           284.6           0.167
AIM-9X Blk I............................       7.7 (3.5)  PBXN-110......................        20 (9.1)      19617.2833           282.6           0.143
AGM-114 (All ex R2 with TM(R10))........         9 (4.1)  PBXN-110......................     13.08 (5.9)      16630.2435           281.2           0.128
AGM-179 JAGM............................         9 (4.1)  PBXN-110......................     13.08 (5.9)      16630.2435           281.2           0.128
AGM-114 R2 with TM (R10)................         8 (3.6)  PBXN-9........................     13.08 (5.9)      17240.2131           281.5           0.124
AGR-20 (APKWS)..........................       2.3 (1.0)  Comp B........................       3.8 (1.7)      10187.8419           276.9           0.090
PGU-43 (105 mm).........................       4.7 (2.1)  Comp B........................      4.72 (2.1)      11118.8384           277.7           0.095
GBU-69..................................       36 (16.3)  Tritonal......................     36.1 (16.4)      22074.1015           283.7           0.198
GBU-70..................................       36 (16.3)  Tritonal......................     36.1 (19.4)      22074.1015           283.7           0.198
GBU-39 SDB (GTV)........................      0.39 (0.2)  PBXN-9........................      0.49 (0.2)       4757.6146           270.3           0.054
GBU-53/B (GTV)..........................      0.34 (0.2)  PBXN-9........................      0.44 (0.2)      4561.06062           270.0           0.053
GBU-12..................................      192 (87.1)  Tritonal......................    192.3 (87.2)      42101.8577           289.3           0.302
Mk-81 (GP 250 lb).......................      100 (45.4)  H-6...........................      100 (45.4)      38017.3815           288.4           0.237
--------------------------------------------------------------------------------------------------------------------------------------------------------
[thgr] = shock wave time constant; AGM = Air-to-Ground Missile; AIM = Air Intercept Missile; APKWS = Advanced Precision Kill Weapon System; dB re 1
  [micro]Pa = decibel(s) referenced to 1 micropascal; FU = Full Up; GBU = Guided Bomb Unit; GP = General Purpose; GTV = Guided Test Vehicle; HACM =
  Hypersonic Attack Cruise Missile; HE = High Explosive; JASSM = Joint Air-to-Surface Standoff Missile; lb = pound(s); lbm = pound-mass; LSDB = Laser
  Small-Diameter Bomb; m = meter(s); Mk = Mark; mm = millimeter(s); msec = millisecond(s); NEW = net explosive weight; NEWi = net explosive weight at
  impact; NLOS = Non-Line-of-Sight; PGU = Projectile Gun Unit; Pmax = shock wave peak pressure; psi = pound(s) per square inch; SDB = Small-Diameter
  Bomb; SPL = sound pressure level; TM = telemetry.

    For SEL analysis, the dBSea model was used with the ray-tracing 
option for calculating the underwater transmission of impulsive noise 
sources represented in a time series (1,000,000 samples per second) as 
calculated using similitude equations (r = 1 meter) for each munition 
for each mission day. All surface detonations are assumed to occur at a 
depth of 1 m, and all subsurface detonations, which would include the 
GBU-10, GBU-24, GBU-31, and subsurface mines, are assumed to occur at a 
depth of 3 m. The model used bathymetry for LIA with detonations 
occurring at the center of the LIA with a water depth of 70 m. The 
seafloor of the LIA is generally sandy, so sandy bottom characteristics 
for reflectivity and attenuation were used in the dBSea model, as 
previously described. The model was used to calculate impulsive 
acoustic noise transmission on one-third octaves from 31.5 hertz to 32 
kilohertz. Maximum SELs from all depths projected to the surface were 
used for the analyses.
    The cumulative SEL is based on multiple parameters including the 
acoustic characteristics of the detonation and sound propagation loss 
in the marine environment, which is influenced by a number of 
environmental factors including water depth and seafloor properties. 
Based on integration of these parameters, the dBSea model predicts the 
distances at which each marine animal species is estimated to 
experience SELs associated with the onset of PTS, TTS, and behavioral 
disturbance. As noted previously, thresholds for the onset of TTS and 
PTS used in the model and pressure calculations are based on those 
presented in Criteria and Thresholds for U.S. Navy Acoustic and 
Explosive Effects Analysis (Phase III) (DoN 2017) for cetaceans with 
mid- to high-frequency hearing (dolphins) and low-frequency hearing 
(Rice's whale). Behavioral thresholds are set 5 dB

[[Page 8173]]

below the SEL-based TTS threshold. Table 24 shows calculated SPLs and 
SELs for the designated mission-day categories.

                      Table 24--Calculated Source SPLs and SELs for Mission-Day Categories
----------------------------------------------------------------------------------------------------------------
                                              Total warhead                           Source
                Mission day                    NEW, lbm \a\    Modeled NEWi, lbm/   cumulative      Source peak
                                                   (kg)               (kg)            SEL, dB         SPL, dB
----------------------------------------------------------------------------------------------------------------
A.........................................     2402.6 (108.6)    2413.6 (1094.6)           262.1             290
B.........................................       1961 (889.3)     2029.9 (920.6)           261.4           289.3
C.........................................       1145 (519.2)     1376.2 (624.1)           259.8           288.3
D.........................................        562 (254.8)     836.22 (379.2)           257.6           288.3
E.........................................     817.88 (370.9)     997.62 (452.0)           257.1           281.5
F.........................................        584 (264.8)      584.6 (265.1)           256.2           289.3
G.........................................          191(86.6)       191.6 (86.9)           250.4           277.7
H.........................................        60.5 (24.7)        61.1 (27.7)           245.2           268.8
I.........................................         18.4 (8.3)        30.4 (13.8)           242.5           276.9
J.........................................        945 (428.6)      946.8 (429.4)           258.1           294.6
K.........................................      Not available        350 (158.7)           253.4           291.5
L.........................................     624.52 (283.2)     627.12 (284.4)           256.2             290
M.........................................        324 (146.9)      324.9 (147.3)           253.2           283.6
N.........................................      219.92 (99.7)     238.08 (107.9)             252           285.3
O.........................................          72 (36.6)      104.64 (47.5)           248.3           281.2
P.........................................          90 (40.8)       130.8 (59.3)           249.3           281.2
Q.........................................          94 (42.6)        94.4 (42.8)           247.5           277.7
R.........................................       35.12 (15.9)       35.82 (16.2)           241.7           270.3
S.........................................         130 (58.9)         130 (58.9)           249.4             283
----------------------------------------------------------------------------------------------------------------
\a\ lbm = pound-mass.

Mission-Day Categories

    The munitions proposed to be used by each military unit were 
grouped into mission-day categories so the acoustic impact analysis 
could be based on the total number of detonations conducted during a 
given mission instead of each individual detonation. This analysis was 
done to account for the accumulated energy from multiple detonations 
over a 24-hour period.
    The estimated number of mission days assigned to each category was 
based on historical numbers and projections provided by certain user 
groups. Although the mission-day categories may not represent the exact 
manner in which munitions would be used, they provide a conservative 
range of mission scenarios to account for accumulated energy from 
multiple detonations. It is important to note that only acoustic energy 
metrics (SEL) are affected by the accumulation of energy over a 24-hour 
period. Pressure metrics (e.g., peak SPL and positive impulse) do not 
accumulate and are based on the highest impulse pressure value within 
the 24-hour period. Based on the categories developed, the total NEWi 
per mission day would range from 2,413.6 to 30.4 lb (1,094.6 to 13.8 
kg). The highest detonation energy of any single munition used under 
the USAF's proposed activities would be 945 lb (428.5 kg) NEW, which 
was also the highest NEW for a single munition in the previous LOA 
Request. The munitions having this NEW include the GBU-10, GBU-24, and 
GBU-31.
    Note that the types of munitions that would be used for SINKEX 
testing are controlled information and, therefore, not identified in 
this LOA Request. For the purpose of analysis, SINKEX exercises are 
assigned to mission-day category J, which represents a single 
subsurface detonation of 945 lb NEW. SINKEX exercises would not exceed 
this NEW. The 2 annual SINKEX exercises are added to the other 8 annual 
missions involving subsurface detonations of these bombs, resulting in 
10 total annual missions under mission-day category J.
    As indicated in Table 25, a total of 19 mission-day categories (A 
through S) were developed a part of this LOA application. The table 
also contains information on the number of munitions per day, number of 
mission days per year, annual quantity of munitions and the NEWi per 
mission day.

                                                                  Table 25--Mission-Day Categories for Acoustic Impact Analysis
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                 Mission-day                                      Warhead NEW (lb)/                        Detonation    Munitions   Mission days     Annual    NEWi per mission
          User group              category       Munition type       Category            (kg)           NEWi (lb)/kg        scenario      per day      per year      quantity    day (lb)/(kg)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
53 WEG.......................  A               AGM-158D JASSM    Missile........     240.26 (108.9)     241.36 (109.4)  Surface........          4               1          4  2,413.6 (1,095.9)
                                                XR.
                                               AGM-158B JASSM    Missile........     240.26 (108.9)     241.36 (109.4)  Surface........          3               1          3  .................
                                                ER.
                                               AGM-158A JASSM..  Missile........     240.26 (108.9)     241.36 (109.4)  Surface........          3               1          3  .................
                               B               GBU-54 KMU-572C/  Bomb (Mk-82)...         192 (87.1)       192.3 (87.2)  Surface........          4               1          4    2,029.9 (920.5)
                                                B.
                                               GBU-54 KMU-572B/  Bomb (Mk-82)...         192 (87.1)       192.3 (87.2)  Surface........          4               1          4  .................
                                                B.
                                               AGM-65D.........  Missile........          85 (38.5)        98.3 (44.6)  Surface........          5               1          5  .................
                               C               AGM-65H2........  Missile........          85 (37.5)        98.3 (44.6)  Surface........          5               1          5    1,376.2 (624.1)
                                               AGM-65G2........  Missile........          85 (38.5)        98.3 (44.6)  Surface........          5               1          5  .................
                                               AGM-65K2........  Missile........          85 (38.5)        98.3 (44.6)  Surface........          4               1          4  .................
                               D               AGM-65L.........  Missile........          85 (38.5)        98.3 (44.6)  Surface........          5               1          5     836.22 (379.2)
                                               AIM-120C3.......  Missile........           15 (6.8)       36.18 (16.4)  Surface........          4               1          4  .................
                                               AIM-9X Blk I....  Missile........          7.7 (4.5)           20 (9.1)  Surface........         10               1         10  .................
                               E               AGM-114 N-4D      Missile........            9 (4.1)        13.08 (5.9)  Surface........          4               1          4     997.62 (452.4)
                                                with TM.
                                               AGM-114 N-6D      Missile........            9 (4.1)        13.08 (5.9)  Surface........          4               1          4  .................
                                                with TM.

[[Page 8174]]

 
                                               AGM-179 JAGM....  Missile........            9 (4.1)        13.08 (5.9)  Surface........          4               1          4  .................
                                               AGM-114 R2 with   Missile........            9 (4.1)        13.08 (5.9)  Surface........          4               1          4  .................
                                                TM (R10).
                                               AGM-114 R-9E      Missile........            9 (4.1)        13.08 (5.9)  Surface........          4               1          4  .................
                                                with TM (R11).
                                               AGM-114Q with TM  Missile........            9 (4.1)        13.08 (5.9)  Surface........          4               1          4  .................
                                               AGR-20 (APKWS)..  Rocket.........          2.3 (1.0)          3.8 (1.7)  Surface........         12               1         12  .................
                                               AGM-176.........  Missile........            9 (4.1)        13.08 (5.9)  Surface........          4               1          4  .................
                                               PGU-43 (105 mm).  Gun Ammunition.          4.7 (2.1)         4.72 (2.1)  Surface........        100               1        100  .................
                                               GBU-69..........  Bomb...........          36 (16.3)        36.1 (13.3)  Surface........          2               1          2  .................
                                               GBU-70..........  Bomb...........          36 (16.3)        36.1 (16.3)  Surface........          1               1          4  .................
                                               AGM-88C w/FTS...  Missile........     \a\ 0.70 (0.3)                  0  Surface........          2               1          2  .................
                                               AGM-88B w/FTS...  Missile........     \a\ 0.70 (0.3)                  0  Surface........          2               1          2  .................
                                               AGM-88F w/FTS...  Missile........     \a\ 0.70 (0.3)                  0  Surface........          2               1          2  .................
                                               AGM-88G w/FTS...  Missile........     \a\ 0.70 (0.3)                  0  Surface........          2               1          2  .................
                                               GBU-39 SDB (GTV)  Bomb...........     \a\ 0.39 (0.2)         0.49 (0.2)  Surface........          4               1          4  .................
                                               GBU-53/B (GTV)..  Bomb...........     \a\ 0.34 (0.2)         0.44 (0.2)  Surface........          8               1          8  .................
AFSOC........................  F               GBU-12..........  Bomb (Mk-82)...         192 (87.1)       192.3 (87.2)  Surface........          2              15         30      584.6 (263.1)
                                               Mk-81 (GP 250     Bomb...........         100 (45.3)         100 (45.3)  Surface........          2              15         30  .................
                                                lb).
AFSOC........................  G               105 mm HE (FU)..  Gun Ammunition.          4.7 (2.1)         4.72 (2.1)  Surface........         30    25 (daytime)        750       191.6 (86.8)
                                               30 mm HE........  Gun Ammunition.          0.1 (0.1)         0.1 (0.01)  Surface........        500                     12,500  .................
                               H               105 mm HE (TR)..  Gun Ammunition.         0.35 (0.2)         0.37 (0.2)  Surface........         30  45 (nighttime)      1,350        61.1 (27.7)
                                               30 mm HE........  Gun Ammunition.          0.1 (0.1)         0.1 (0.01)  Surface........        500                     22,500  .................
                               I               2.75-inch Rocket  Rocket.........          2.3 (1.0)          3.8 (1.7)  Surface........          8              50        400        30.4 (13.8)
                                                (including
                                                APKWS).
96 OG........................  J               GBU-10, 24, or    Bomb (Mk-84)...        945 (428.6)      946.8 (429.4)  Subsurface.....          1          \b\ 10     \b\ 10      946.8 (429.4)
                                                31 (QUICKSINK).
                               K               HACM............  Hypersonic           Not available        350 (158.7)  Surface........          1               1          2        350 (158.7)
                                                                  Weapon.
                               L               AGM-158 (JASSM).  Missile........     240.26 (108.9)     241.36 (109.4)  Surface........          2               1          2     627.12 (284.3)
                                               GBU-39 (SDB I)    Bomb...........          72 (32.6)        72.2 (32.7)  Surface........          2               1          2  .................
                                                Simultaneous
                                                Launch \c\.
                               M               GBU-39 (SDB I)..  Bomb...........          36 (16.3)         36.1 13.3)  Surface........          4               2          8      324.9 (147.3)
                                               GBU-39 (LSDB)...  Bomb...........          36 (16.3)        36.1 (16.3)  Surface........          5               2         10  .................
                               N               GBU-39B/B LSDB..  Bomb...........          36 (16.3)        36.1 (16.3)  Surface........          2               1          2     238.08 (107.9)
                                               Spike NLOS......  Missile........       34.08 (15.4)          40 (18.1)  Surface........          3               1          3  .................
                                               GBU-53 (SDB II).  Bomb...........       22.84 (13.4)       22.94 (10.4)  Surface........          2               1          2  .................
                               O               AGM-114R          Missile........            9 (4.1)        13.08 (5.9)  Surface........          8               4         36      104.64 (47.5)
                                                Hellfire.
                               P               AGM-114 Hellfire  Missile........            9 (4.1)        13.08 (5.9)  Surface........          5               2         10       130.8 (59.3)
                                               AGM-176 Griffin.  Missile........            9 (4.1)        13.08 (5.9)  Surface........          5               2         10  .................
                               Q               105 mm HE (FU)..  Gun Ammunition.          4.7 (2.1)         4.72 (2.1)  Surface........         20               3         60        94.4 (42.8)
                               R               Inert GBU-39      Bomb...........         0.39 (0.2)         0.49 (0.2)  Surface........          4               1          4       35.82 (16.2)
                                                (LSDB) with
                                                live fuze.
                                               Inert GBU-53      Bomb...........         0.34 (0.2)         0.44 (0.2)  Surface........          4               1          4  .................
                                                (SDB II) with
                                                live fuze.
                                               105 mm HE (TR)..  Gun Ammunition.         0.35 (0.2)         0.37 (0.2)  Surface........         60               1         60  .................
                                               30 mm HE........  Gun Ammunition.          0.1 (0.1)         0.1 (0.01)  Surface........         99               1         99  .................
NAVSCOL EOD..................  S               Underwater Mine   Charge.........      \d\ 20 (9.07)          20 (9.07)  Subsurface.....          4               8         32         130 (58.9)
                                                Charge.
                                               Floating Mine     Charge.........        \d\ 5 (2.3)            5 (2.3)  Surface........         10               8         80  .................
                                                Charge.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Warhead replaced by FTS/TM. Identified NEW is for the FTS.
\b\ Includes 2 SINKEX exercises.
\c\ NEW is doubled for simultaneous launch.
\d\ Estimated.

Marine Mammal Density

    Densities of the common bottlenose dolphin, Atlantic spotted 
dolphin, and Rice's whale in the study area are based on habitat-based 
density models and spatial density models developed by the NOAA 
Southeast Fisheries Science Center for the species in the Gulf of 
Mexico (NOAA 2022). The density models, herein referred to as the NOAA 
model, integrated visual observations from aerial and shipboard surveys 
conducted in the Gulf of Mexico from 2003 to 2019.
    The NOAA model was used to predict the average density of the 
common bottlenose dolphin and Atlantic spotted dolphin in the existing 
LIA and proposed East LIA. The model generates densities for hexagon-
shaped raster grids that are 40 square kilometers (km\2\). The average 
annual density of each dolphin species in the existing LIA and proposed 
East LIA was computed in a geographic information system (GIS) based on 
the densities of the raster grids within the boundaries of each LIA. To 
account for portions of the grids outside of the LIA, the species 
density value of each grid was area-weighted based on the respective 
area of the grid within the LIA. For example, the density of a grid 
that is 70 percent within the LIA would be weighted to reflect only the 
70 percent grid area, which contributes to the average density of the 
entire LIA. The density of the 30 percent grid area outside the LIA 
does not contribute to the average LIA density, so it is not included 
in the estimation. The resulting area-weighted densities of all the 
grids were summed to determine the average annual density of each 
dolphin species within each LIA. The densities of dolphins estimated 
are presented in Table 26.

[[Page 8175]]



 Table 26--Predicted Dolphin Densities in the Existing and Proposed LIAs
------------------------------------------------------------------------
                                           Density estimate (animals per
                                                    km\2\) \a\
                 Species                 -------------------------------
                                                           Proposed east
                                           Existing LIA         LIA
------------------------------------------------------------------------
Atlantic spotted dolphin................           0.032           0.038
Common bottlenose dolphin...............           0.261           0.317
------------------------------------------------------------------------
\a\ Estimated average density within LIA based on spatial density model
  developed by NOAA (2022).

    The NOAA model was used to determine Rice's whale density in the 
exposure analysis conducted for the Rice's whale in this LOA Request. 
Areas of Rice's whale exposure to pressure and impulsive noise from 
munitions use, predicted by underwater acoustic modeling and quantified 
by GIS analysis, were coupled with the associated modeled grid 
densities from the NOAA model to estimate abundance of affected 
animals.

Take Estimation

    The distances from the live ammunition detonation point that 
correspond to the various effect thresholds described previously are 
referred to as threshold distances. The threshold distances were 
calculated using dBSea for each mission-day category for each marine 
mammal species. The model was run assuming that the detonation point is 
at the center of the existing LIA, the SEL threshold distances are the 
same for the proposed East LIA, and all missions are conducted in 
either the existing LIA or proposed East LIA. Model outputs for the two 
LIAs are statistically the same as a result of similarities in water 
depths, sea bottom profiles, water temperatures, and other 
environmental characteristics. Table 27, Table 28 and Table 29 present 
the threshold distances estimated for the dolphins and Rice's whale, 
respectively, for live missions in the existing LIA.
    The threshold distances were used to calculate the harassment zones 
for each effect threshold for each species. The thresholds resemble 
concentric circles, with the most severe (mortality) being closest to 
the center (detonation point) and the least severe (behavioral 
disturbance) being farthest from the center. The areas encompassed by 
the concentric thresholds are the impact areas associated with the 
applicable criteria. To prevent double counting of animals, areas 
associated with higher-impact criteria were subtracted from areas 
associated with lower-impact criteria. To estimate the number of 
animals potentially exposed to the various thresholds within the 
harassment zone, the adjusted impact area was multiplied by the 
predicted animal density and the annual number of events for each 
mission-day category. The results were rounded at the annual mission-
day level and then summed for each criterion to estimate the total 
annual take numbers for each species. For impulse and SPL metrics, a 
take is considered to occur if the received level is equal to or above 
the associated threshold. For SEL metrics, a take is considered to 
occur if the received level is equal to or above the associated 
threshold within the appropriate frequency band of the sound received, 
adjusted for the appropriate weighting function value of that frequency 
band. For impact categories with multiple criteria (e.g., non-auditory 
injury and PTS for Level A harassment) and criteria with two thresholds 
(e.g., SEL and SPL for PTS), the criterion and/or threshold that 
yielded the higher exposure estimate was used. Threshold distances for 
dolphins are shown in Table 27 and 28, while Table 29 contains 
threshold distances for Rice's whale.

                                           Table 27--Bottlenose Dolphin Threshold Distances (in km) for Live Missions in the Existing Live Impact Area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Mortality                          Level A harassment                                      Level B harassment
                                                                 -------------------------------------------------------------------------------------------------------------------------------
                                                                                   Slight  lung      GI tract                   PTS                             TTS               Behavioral \a\
                                                                                      injury          injury     -------------------------------------------------------------------------------
                                                                     Positive    --------------------------------
                      Mission-day category                          impulse B:       Positive
                                                                       248.4        impulse B:
                                                                    Pa[middot]s        114.5       Peak SPL  237   Weighted SEL    Peak SPL 230    Weighted SEL    Peak SPL 224    Weighted SEL
                                                                     AS: 197.1      Pa[middot]s         dB            185 dB            dB            170 dB            dB            165 dB
                                                                    Pa[middot]s      AS: 90.9
                                                                                    Pa[middot]s
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Bottlenose Dolphin
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A...............................................................           0.139           0.276           0.194           0.562           0.389            5.59           0.706           9.538
B...............................................................           0.128           0.254           0.180           0.581           0.361           5.215           0.655           8.937
C...............................................................           0.100           0.199           0.144           0.543           0.289           4.459           0.524           7.568
D...............................................................           0.100           0.199           0.144           0.471           0.289           3.251           0.524           5.664
E...............................................................           0.068           0.136           0.103           0.479           0.207           3.272           0.377            5.88
F...............................................................           0.128           0.254           0.180           0.352           0.362           2.338           0.655           4.596
G...............................................................           0.027           0.054           0.048           0.274           0.093           1.095           0.165           2.488
H...............................................................           0.010           0.019           0.021           0.225           0.040           0.809           0.071           1.409
I...............................................................           0.025           0.049           0.045           0.136           0.087           0.536           0.154           0.918
J...............................................................           0.228           0.449           0.306           0.678           0.615           3.458           1.115           6.193
K...............................................................           0.158           0.313           0.222           0.258           0.445           1.263           0.808           2.663
L...............................................................           0.139           0.276           0.194           0.347           0.389            2.35           0.706           4.656
M...............................................................           0.068           0.136           0.103           0.286           0.207           1.446           0.377           3.508
N...............................................................           0.073           0.145           0.113            0.25           0.225           1.432           0.404           2.935
O...............................................................           0.046           0.092           0.078           0.185           0.155           0.795           0.278           1.878
P...............................................................           0.046           0.092           0.078           0.204           0.155           0.907           0.278           2.172
Q...............................................................           0.027           0.054           0.048           0.247           0.093           0.931           0.165           1.563
R...............................................................           0.012           0.024           0.026           0.139           0.052           0.537           0.093            0.91

[[Page 8176]]

 
S...............................................................           0.053           0.104           0.084           0.429           0.164           1.699           0.294           2.872
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Behavioral threshold for multiple detonations assumes TTS threshold minus 5 dB.


                                        Table 28--Atlantic Spotted Dolphin Threshold Distances (in km) for Live Missions in the Existing Live Impact Area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Mortality                          Level A harassment                                      Level B harassment
                                                                 -------------------------------------------------------------------------------------------------------------------------------
                                                                                    Slight lung      GI tract                   PTS                             TTS               Behavioral \a\
                                                                                      injury          injury     -------------------------------------------------------------------------------
                                                                     Positive    --------------------------------
                      Mission-day category                          impulse B:       Positive
                                                                       248.4        impulse B:
                                                                    Pa[middot]s        114.5       Peak SPL  237   Weighted SEL    Peak SPL 230    Weighted SEL    Peak SPL 224    Weighted SEL
                                                                     AS: 197.1      Pa[middot]s         dB            185 dB            dB            170 dB            dB            165 dB
                                                                    Pa[middot]s      AS: 90.9
                                                                                    Pa[middot]s
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Atlantic Spotted Dolphin
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A...............................................................           0.171           0.338           0.194           0.562           0.389            5.59           0.706           9.538
B...............................................................           0.157           0.311           0.180           0.581           0.361           5.215           0.655           8.937
C...............................................................           0.123           0.244           0.144           0.543           0.289           4.459           0.524           7.568
D...............................................................           0.123           0.244           0.144           0.471           0.289           3.251           0.524           5.664
E...............................................................           0.084           0.168           0.103           0.479           0.207           3.272           0.377            5.88
F...............................................................           0.157           0.312           0.180           0.352           0.362           2.338           0.655           4.596
G...............................................................           0.033           0.066           0.048           0.274           0.093           1.095           0.165           2.488
H...............................................................           0.012           0.023           0.021           0.225           0.040           0.809           0.071           1.409
I...............................................................           0.030           0.060           0.045           0.136           0.087           0.536           0.154           0.918
J...............................................................           0.279           0.550           0.306           0.678           0.615           3.458           1.115           6.193
K...............................................................           0.194           0.384           0.222           0.258           0.445           1.263           0.808           2.663
L...............................................................           0.171           0.338           0.194           0.347           0.389            2.35           0.706           4.656
M...............................................................           0.084           0.168           0.103           0.286           0.207           1.446           0.377           3.508
N...............................................................           0.090           0.179           0.113            0.25           0.225           1.432           0.404           2.935
O...............................................................           0.057           0.113           0.078           0.185           0.155           0.795           0.278           1.878
P...............................................................           0.057           0.113           0.078           0.204           0.155           0.907           0.278           2.172
Q...............................................................           0.033           0.066           0.048           0.247           0.093           0.931           0.165           1.563
R...............................................................           0.015           0.030           0.026           0.139           0.052           0.537           0.093            0.91
S...............................................................           0.065           0.128           0.084           0.429           0.164           1.699           0.294           2.872
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Behavioral threshold for multiple detonations assumes TTS threshold minus 5 dB.


                                              Table 29--Rice's Whale Threshold Distances (in km) for Live Missions in the Existing Live Impact Area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Mortality                          Level A harassment                                      Level B harassment
                                                                 -------------------------------------------------------------------------------------------------------------------------------
                                                                                    Slight lung      GI tract                   PTS                             TTS               Behavioral \a\
                                                                                      injury          injury     -------------------------------------------------------------------------------
                      Mission-day category                           Positive    --------------------------------
                                                                   impulse 906.2     Positive                      Weighted SEL    Peak SPL 219    Weighted SEL    Peak SPL 213    Weighted SEL
                                                                    Pa[middot]s    impulse 417.9   Peak SPL 237       183 dB            dB            168 dB            dB            163 dB
                                                                                    Pa[middot]s         dB
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A...............................................................           0.044           0.088           0.194           5.695           1.170          21.435           2.120          27.923
B...............................................................           0.041            0.81           0.180           5.253           1.076          20.641           1.955          26.845
C...............................................................           0.031           0.063           0.144           4.332           0.861          18.772           1.562          24.526
D...............................................................           0.031           0.063           0.144           2.979           0.861          16.419           1.562          21.579
E...............................................................           0.021           0.043           0.103           2.323           0.617          15.814           1.121           21.22
F...............................................................           0.041           0.081           0.180           2.208           1.076          14.403           1.955          19.439
G...............................................................           0.009           0.017           0.048           0.494           0.266           7.532           0.470           12.92
H...............................................................           0.003           0.006           0.021           0.401           0.114           3.624           0.201           7.065
I...............................................................           0.008           0.016           0.045           0.305           0.247            2.95           0.437           6.059
J...............................................................           0.073           0.145           0.306           4.487           1.830          13.216           3.323           16.88
K...............................................................           0.050           0.100           0.222           0.831           1.320           7.723           2.393          11.809
L...............................................................           0.044           0.088           0.194           2.325           1.170          15.216           2.120          20.319
M...............................................................           0.021           0.043           0.103           1.304           0.617          11.582           1.121          16.688
N...............................................................           0.023           0.046           0.113           1.026           0.658           9.904           1.183          14.859
O...............................................................           0.015           0.029           0.078           0.611           0.460           6.926           0.832          11.159
P...............................................................           0.014           0.029           0.078           0.671           0.460           7.841           0.832          12.307
Q...............................................................           0.009           0.017           0.048           0.549           0.266           6.299           0.470          10.393
R...............................................................           0.004           0.008           0.026           0.283           0.152           2.383           0.273            5.06
S...............................................................           0.017           0.034           0.084           0.938           0.473           8.676           0.843          12.874
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Behavioral threshold for multiple detonations assumes TTS threshold minus 5 dB.


[[Page 8177]]

    As discussed previously and shown in Table 22, a portion of the 
kinetic energy released by an inert munition at impact is transmitted 
as underwater acoustic energy in a pressure impulse. The proposed inert 
munitions were categorized into four classes based on their impact 
energies to assess the potential impacts of inert munitions on marine 
mammals. The threshold distances for each class were modeled and 
calculated as described for the mission-day categories. Table 30 
presents the impact energy classes developed for the proposed inert 
munitions. The four impact energy classes represent the entire suite of 
inert munitions proposed to be used in the EGTTR during the next 
mission period. The impact energy is the portion of the kinetic energy 
at impact that is transmitted as an underwater pressure impulse, 
expressed in units of TNT-equivalent (TNTeq). Tables 30 and 31 present 
the threshold distances estimated for the dolphins and Rice's whale, 
respectively, for inert munitions in the existing LIA.

                           Table 30--Dolphin Threshold Distances (in km) for Inert Munitions in the Existing Live Impact Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                             Mortality                          Level A harassment                                      Level B harassment
                         -------------------------------------------------------------------------------------------------------------------------------
                                            Slight lung      GI tract                   PTS                     TTS               Behavioral \a\
                                              injury          injury     -------------------------------------------------------------------------------
                             Positive    --------------------------------
 Inert impact class (lb     impulse B:       Positive
         TNTeq)                248.4        impulse B:
                            Pa[middot]s        114.5       Peak SPL 237    Weighted SEL    Peak SPL 230    Weighted SEL    Peak SPL 224    Weighted SEL
                             AS: 197.1      Pa[middot]s         dB            185 dB            dB            170 dB            dB            165 dB
                            Pa[middot]s      AS: 90.9
                                            Pa[middot]s
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Bottlenose Dolphin
--------------------------------------------------------------------------------------------------------------------------------------------------------
2.......................           0.020           0.041           0.040           0.030           0.080           0.205           0.145           0.327
1.......................           0.015           0.031           0.032           0.025           0.063           0.134           0.114           0.250
0.5.....................           0.012           0.023           0.025           0.015           0.050           0.119           0.091           0.198
0.15....................           0.008           0.015           0.017           0.009           0.034           0.061           0.061           0.119
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Atlantic Spotted Dolphin
--------------------------------------------------------------------------------------------------------------------------------------------------------
2.......................           0.025           0.051           0.040           0.030           0.080           0.205           0.145           0.327
1.......................           0.019           0.038           0.032           0.025           0.063           0.134           0.114           0.250
0.5.....................           0.014           0.029           0.025           0.015           0.050           0.119           0.091           0.198
0.15....................           0.009           0.018           0.017           0.009           0.034           0.061           0.061           0.119
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Behavioral threshold for multiple detonations assumes TTS threshold minus 5 dB.


                         Table 31--Rice's Whale Threshold Distances (in km) for Inert Munitions in the Existing Live Impact Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                             Mortality                          Level A harassment                                      Level B harassment
                         -------------------------------------------------------------------------------------------------------------------------------
                                            Slight lung      GI tract                   PTS                     TTS               Behavioral \a\
 Inert impact class (lb                       injury          injury     -------------------------------------------------------------------------------
         TNTeq)              Positive    --------------------------------
                           impulse 906.2     Positive                      Weighted SEL    Peak SPL 219    Weighted SEL    Peak SPL 213    Weighted SEL
                            Pa[middot]s    impulse 417.9   Peak SPL 237       183 dB            dB            168 dB            dB            163 dB
                                            Pa[middot]s         dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
2.......................           0.006           0.013           0.040           0.151           0.238           0.474           0.430           0.884
1.......................           0.005           0.010           0.032           0.110           0.188           0.327           0.340           0.542
0.5.....................           0.004           0.007           0.025           0.055           0.149           0.261           0.270           0.521
0.15....................           0.002           0.005           0.017           0.026           0.100           0.154           0.181           0.284
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Behavioral threshold for multiple detonations assumes TTS threshold minus 5 dB.

Dolphin Species

    Estimated takes for dolphins are based on the area of the Level A 
and Level B harassment zones, predicted dolphin density, and annual 
number of events for each mission-day category. As previously 
discussed, take estimates for dolphins are based on the average yearly 
density of each dolphin species in each LIA. To estimate the takes of 
each dolphin species in both LIAs collectively, the take estimates for 
each LIA were weighted based on the expected usage of each LIA over the 
7-year mission period. This information was provided by the user 
groups. Ninety percent of the total missions are expected to be 
conducted in the existing LIA and 10 percent are expected to be 
conducted in the proposed East LIA. Therefore, total estimated takes 
are the sum of 90 percent of the takes in the existing LIA and 10 
percent of the takes in the proposed East LIA. Should the usage ratio 
changes substantially in the future, USAF would re-evaluate the 
exposure estimates and reinitiate consultation with NMFS to determine 
whether the take estimations need to be adjusted.

             Table 32--Calculated Annual Exposures of Dolphins Under the USAF's Proposed Activities
----------------------------------------------------------------------------------------------------------------
                                                        Level A harassment              Level B harassment
                                     Mortality   ---------------------------------------------------------------
                                                    Injury \a\          PTS             TTS         Behavioral
----------------------------------------------------------------------------------------------------------------
                                               Bottlenose Dolphin
----------------------------------------------------------------------------------------------------------------
Missions at Existing LIA........            0.74            2.14            9.25           312.7           799.7
Missions at East LIA............            0.89             2.6           11.24          379.79          971.29
90 Percent of Existing LIA                  0.66            1.92            8.33           281.4          719.73
 Missions.......................

[[Page 8178]]

 
10 Percent of East LIA Missions.            0.09            0.26            1.12           37.98           97.13
                                 -------------------------------------------------------------------------------
    Total.......................            0.75            2.18            9.45          319.14          816.86
                                 -------------------------------------------------------------------------------
        Total Takes Requested...               0               0               9             319             817
----------------------------------------------------------------------------------------------------------------
                                            Atlantic Spotted Dolphin
----------------------------------------------------------------------------------------------------------------
Missions at Existing LIA........            0.14            0.39            0.96           38.34           98.05
Missions at East LIA............            0.16            0.47            1.14           45.53          116.43
90 Percent of Existing LIA                  0.12            0.36            0.86           34.50           88.24
 Missions.......................
10 Percent of East LIA Missions.            0.02            0.05            0.11            4.55           11.64
                                 -------------------------------------------------------------------------------
    Total.......................            0.14             0.4            0.98           39.06           99.89
                                 -------------------------------------------------------------------------------
        Total Takes Proposed....               0               0               1              39             100
----------------------------------------------------------------------------------------------------------------
\a\ Slight lung and/or gastrointestinal tract injury.

    The annual exposures of dolphins requested by the USAF and proposed 
for authorization by NMFS are presented in Table 32. As indicated, a 
total of 9 Level A harassment takes and 1,136 Level B harassment takes 
of the common bottlenose dolphin, and 1 Level A harassment takes and 
139 Level B harassment takes of the Atlantic spotted dolphin are 
requested annually for EGTTR operations during the next 7-year mission 
period. The presented takes are overestimates of actual exposure based 
on the conservative assumption that all proposed detonations would 
occur at or just below the water surface instead of a portion occurring 
upon impact with targets.
    Based on the best available science, the USAF (in coordination with 
NMFS) used the acoustic and pressure thresholds indicated in Tables 26-
30 to predict the onset of tissue damage and mortality for explosives 
(impulsive) and other impulsive sound sources for inert and live 
munitions in both the existing LIA and proposed East LIA. The mortality 
takes calculated for the bottlenose dolphin (0.75) and Atlantic spotted 
dolphin (0.14) are both less than one animal. Mortality for Rice's 
whale is zero. Therefore, and in consideration of the required 
mitigation measures, no mortality takes are requested for either 
dolphin species or Rice's whale. The non-auditory injury takes are 
calculated to be 2.18 and 0.40 for the bottlenose dolphin and Atlantic 
spotted dolphin, respectively. However, these (and the take estimates 
for the other effect thresholds) are the sum of the respective takes 
for all 19 mission-day categories. Each individual mission-day category 
results in a fraction of a non-auditory injury take. Given the required 
mitigation, adding up all the fractional takes in this manner would 
likely result in an over-estimate of take. Calculated non-auditory 
injury for the Rice's whale is zero.
    The mitigation measures associated with explosives are expected to 
be effective in preventing mortality and non-auditory tissue damage to 
any potentially affected species. All of the calculated distances to 
mortality or non-auditory injury thresholds are less than 400 m. The 
USAF would be required to employ trained protected species observers 
(PSOs) to monitor the mitigation zones based on the mission-day 
activities. The mitigation zone is defined as double the threshold 
distance at which Level A harassment exposures in the form of PTS could 
occur (also referred to below as ``double the Level A PTS threshold 
distance''). During pre-monitoring PSOs would be required to postpone 
or cancel operations if animals are found in these zones. Protected 
species monitoring would be vessel-based, aerial-based or remote video-
based depending on the mission-day activities. The USAF would also be 
required to conduct testing and training exercise beyond setback 
distances shown in Table 33. These setback distances would start from 
the 100-m isobath, which is approximately the shallowest depth where 
the Rice's whale has been observed. The setback distances are based on 
the PTS threshold calculated for the Rice's whale depending on the 
mission-day activity. Also, all gunnery missions must take place 500 m 
landward of the 100-m isopleth to avoid impacts to the Rice's whale. 
When these mitigation measures are considered in combination with the 
modeled exposure results, no species are anticipated to incur mortality 
or non-auditory tissue damage during the period of this rule.
    Based on the conservative assumptions applied to the impact 
analysis and the pre-mission surveys conducted for dolphins, which 
extend out to, at a minimum, twice the PTS threshold distance that 
applies to both dolphin species (185 dB SEL), NMFS has determined that 
no mortality or non-auditory injury takes are expected and none are 
authorized for EGTTR operations.

Rice's Whale

    Figure 6-2 in the LOA application shows the estimated Rice's whale 
threshold distances and associated harassment zones for mission-day 
category A, J, and P and use of a 2 lb class inert munition at the 
location where the GRATV is typically anchored in the existing LIA. As 
indicated on Figure 6-2, portions of the behavioral harassment zone of 
mission-day categories A and J extend into Rice's whale habitat, 
whereas the monitoring zones for mission-day category P and the largest 
inert munition are entirely outside Rice's whale habitat. The 
monitoring zone is defined as the area between double the Level A 
harassment mitigation zone and the human safety zone perimeter. As 
previously discussed, the spatial density model developed by NOAA 
(2022) for the Rice's whale was used to predict Rice's whale density 
for the purpose of estimating takes. The NOAA model generates densities 
for hexagon-shaped raster grids that are 40 km\2\. The specific areas 
of the raster grids within each of the Level A and Level B harassment 
zones were computed in GIS and coupled with their respective modeled

[[Page 8179]]

densities to estimate the number of animals that would be exposed.
    Figure 6-3 in the LOA application shows the harassment zones of 
mission-day category A at the current GRATV anchoring site. As shown, 
portions of the mitigation zones (TTS and behavioral disturbance) are 
within grids of modeled density greater than zero individuals per 40 
km\2\. However, the modeled densities in these areas are small and 
reflect higher occurrence probability for the Rice's whale farther to 
the southwest, outside the LIA. To estimate annual takes, the number of 
animals in all model grids within each mitigation, monitoring zone, and 
Level B harassment (behavioral) zone for all mission-day categories, 
except gunnery missions (G and H), were computed using the densities 
from the NOAA model (2022) model and the impact areas calculated in 
GIS. The modeled densities and the associated areas were multiplied 
together to estimate abundance within each mitigation, monitoring, and 
Level B harassment zone. The resulting abundance estimates were summed 
together and then multiplied by the number of annual missions proposed 
to estimate annual takes. These calculations resulted in a total of 
0.04 annual TTS take and 0.10 annual behavioral disturbance take, which 
indicates that all missions conducted at the current GRATV site 
combined would not result in a single Level B harassment take of the 
Rice's whale. For comparison, Figure 6-4 shows the harassment zones of 
mission-day category A at the center of the proposed East LIA. As 
shown, a small portion of the behavioral disturbance zone (27.9 km) 
encompasses a grid of low modeled density, with grids of higher density 
being farther to the southwest.
    Certain missions could have a PTS impact if they were to be 
conducted farther to the southwest within the LIAs closer to Rice's 
whale habitat, as defined by the 100-m isobath. The modeled threshold 
distances were used to determine the locations in the existing LIA and 
proposed East LIA where each mission-day category would cause the onset 
of PTS, measured as a setback from the 100-m isobath. At this setback 
location, the mission would avoid PTS and result only in non-injury 
Level B harassment, if one or more Rice's whales were in the affected 
habitat. The setback distances are based on the longest distance 
predicted by the dBSea model for a cumulative SEL of 168 dB within the 
mitigation zone; the predicted average cumulative SEL is used as the 
basis of effect for estimating takes. The setback distances determined 
for the mission-day categories are presented in Table 33 and are shown 
for the existing LIA and proposed East LIA on Figures 6-5 and 6-6, 
respectively.

               Table 33--Setbacks To Prevent Permanent Threshold Shift Impacts to the Rice's Whale
----------------------------------------------------------------------------------------------------------------
                                                                                               Setback from 100-
               User group                       Mission-day  category         NEWi (lb)/(kg)     meter isobath
                                                                                                   (km)/(nmi)
----------------------------------------------------------------------------------------------------------------
53 WEG..................................  A                                  2,413.6 (1094.6)       7.323 (3.95)
                                          B                                   2,029.9 (920.6)       6.659 (5.59)
                                          C                                   1,376.2 (624.1)       5.277 (2.84)
                                          D                                    836.22 (379.2)       3.557 (1.92)
                                          E                                     934.9 (423.9)       3.192 (1.72)
AFSOC...................................  F                                     584.6 (265.1)       3.169 (1.71)
                                          I                                       29.6 (13.4)       0.394 (0.21)
96 OG...................................  J                                      946.8 (429.4        5.188 (2.80
                                          K                                       350 (158.7)       1.338 (0.72)
                                          L                                     627.1 (284.3)       3.315 (1.78)
                                          M                                     324.9 (147.3)       2.017 (1.08)
                                          N                                     238.1 (107.9)       1.815 (0.98)
                                          O                                      104.6 (47.5)       0.734 (0.39)
                                          P                                      130.8 (59.3)       0.787 (0.42)
                                          Q                                       94.4 (42.8)       0.667 (0.36)
                                          R                                       37.1 (16.8)       0.368 (0.19)
NAVSCOLEOD..............................  S                                        130 (58.9)       1.042 (0.56)
----------------------------------------------------------------------------------------------------------------

    Locating a given mission in the LIA at its respective setback 
distance would represent the maximum Level B harassment scenario for 
the mission. If all the missions were conducted at their respective 
setbacks, the resulting takes would represent the maximum Level B 
harassment takes that would result for all mission-day categories 
except for gunnery missions. This is not a realistic scenario; however, 
it is analyzed to provide a worst-case estimate of takes. The takes 
under this scenario were calculated using the NOAA model (2022) model 
as described for the GRATV Location scenario. Figure 6-7 shows mission-
day category A conducted at its maximum Level B setback location (7.23 
km). Under this scenario, the TTS and behavioral disturbance mitigation 
zones extend farther into Rice's whale habitat. However, the modeled 
densities within affected areas are still relatively small. PTS impacts 
are avoided entirely. The PTS mitigation zone is slightly offset from 
the 100-m isobath because the setback is based on the longest distance 
predicted by the dBSea model, whereas the mitigation zones shown are 
based on the average distance predicted by the model. The take 
calculations for the maximum Level B harassment scenario resulted in a 
total of 0.49 annual TTS takes and 1.19 annual behavioral disturbance 
takes as shown in Table 34. These are the maximum number of takes 
estimated to potentially result from detonations in the existing LIA. 
These takes are overestimates because a considerable portion of all 
missions in the LIA are expected to continue to be conducted at or near 
the currently used GRATV anchoring site. These takes would not be 
exceeded because all missions will be conducted behind their identified 
setbacks as a new mitigation measure to prevent injury to the Rice's 
whale. Take calculations for the maximum Level B harassment scenario in 
the East LIA resulted in 0.63 annual TTS takes and 2.33 annual 
behavioral disturbance takes (Table 34). However, if we assume that 90 
percent of the mission would occur in existing LIA and 10 percent would 
occur in the proposed East LIA as was done for

[[Page 8180]]

dolphins, the estimated result is 0.55 annual TTS (0.49 + 0.06) and 
1.42 annual behavioral (1.19 + 0.23) takes.
    The take calculations were performed using the NOAA (2022) density 
model for both day and night gunnery missions. As indicated on Figures 
6-8 and 6-9 in the application, the modeled Rice's whale densities in 
the TTS and behavioral disturbance zones are small, and reflect a 
higher occurrence probability for the Rice's whale farther to the 
southwest. The take calculations estimated 0.003 TTS takes and 0.012 
behavioral disturbance takes per daytime gunnery mission and 0.0006 TTS 
takes and 0.002 behavioral disturbance takes per nighttime gunnery 
mission. The resulting annual takes for all proposed 25 daytime gunnery 
missions are 0.08 TTS take and 0.30 behavioral disturbance take, and 
the resulting annual takes for all 45 proposed nighttime gunnery 
missions are 0.03 TTS take and 0.09 behavioral disturbance take (Table 
34). This is a conservative estimation of Level B harassment takes 
because all gunnery missions would not be conducted precisely 500 m 
landward of the 100-m isobath as assumed under this worst-case take 
scenario. This represents a mitigation measure described later in the 
Proposed Mitigation section. Based on a review of gunnery mission 
locations, most gunnery missions during the last 5 years have occurred 
in waters shallower than 100 m.
    The annual maximum Level B harassment takes estimated for daytime 
gunnery missions (mission-day G) and nighttime gunnery missions 
(mission-day category H) are combined with the annual maximum Level B 
harassment takes estimated for the other mission-day categories to 
determine the total takes of the Rice's whale from all EGTTR operations 
during the next mission period. The annual takes of the Rice's whale 
requested under the USAF's proposed activities are 0.61 TTS takes 
conservatively and 1.69 behavioral takes as presented in Table 34. 
However, the average group size for Bryde's whales found in the 
northeast Gulf of Mexico is two animals (Maze-Foley and Mullin 2006). 
NMFS will assume that each exposure would result in take of two 
animals. Therefore, NMFS is proposing to authorize Level B harassment 
in the form of two takes by TTS and four takes by behavioral 
disturbance annually for EGTTR operations during the next 7-year 
mission period.
    Note that the requested takes are likely overestimates because they 
represent the maximum Level B harassment scenario for all missions. 
These takes are also likely overestimates of actual exposure based on 
the conservative assumption that all proposed detonations would occur 
at or just below the water surface instead of a portion occurring upon 
impact with targets.

         Table 34--Calculated Annual Exposures of the Rice's Whale Under the USAF's Proposed Activities
----------------------------------------------------------------------------------------------------------------
                                                        Level A harassment              Level B harassment
                                                 ---------------------------------------------------------------
                                                    Injury \a\          PTS             TTS         Behavioral
----------------------------------------------------------------------------------------------------------------
Missions at Existing LIA........               0               0               0            0.49            1.19
Missions at East LIA............               0               0               0            0.63            2.33
90 Percent of Existing LIA                     0               0               0           0.441           1.071
 Missions.......................
10 Percent of East LIA Missions.               0               0               0           0.063           0.233
Daytime Gunnery Missions........               0               0               0            0.08            0.30
Nighttime Gunnery Missions......               0               0               0            0.03            0.09
                                 -------------------------------------------------------------------------------
    Total.......................               0               0               0            0.61            1.69
                                 -------------------------------------------------------------------------------
    Total Takes Requested.......               0               0               0           2 \b\           4 \b\
----------------------------------------------------------------------------------------------------------------
\a\ Slight lung and/or gastrointestinal tract injury.
\b\ Based on average group size (Maze-Foley and Mullin (2006).

    For the USAF's proposed activities in the EGTTR, Table 35 
summarizes the take NMFS proposes, to authorize, including the maximum 
annual, 7-year total amount, and type of Level A harassment and Level B 
harassment that NMFS anticipates is reasonably likely to occur by 
species and stock. Note that take by Level B harassment includes both 
behavioral disturbance and TTS. No mortality or non-auditory injury is 
anticipated or proposed, as described previously.

 Table 35--Proposed Annual and Seven-Year Total Species-specific Take Authorization From Explosives for All Training and Testing Activities in the EGTTR
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Proposed annual take                         Proposed 7-year total take
                                                         -----------------------------------------------------------------------------------------------
                                                              Level A                 Level B                 Level A                 Level B
            Common name                   Stock/DPS      -----------------------------------------------------------------------------------------------
                                                                                            Behavioral                                      Behavioral
                                                                PTS             TTS         disturbance         PTS             TTS         disturbance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Common bottlenose dolphin.........  Northern Gulf of                   9             319             817              63           2,233           5,719
                                     Mexico Continental
                                     Shelf.
Atlantic spotted dolphin..........  Northern Gulf of                   1              39             100               7             273             700
                                     Mexico.
Rice's whale *....................  NSD.................               0               2               4               0              14              28
--------------------------------------------------------------------------------------------------------------------------------------------------------
* ESA-listed species.
Note: NSD = No stock designation.


[[Page 8181]]

Proposed Mitigation

    Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the 
permissible methods of taking pursuant to the activity, and other means 
of effecting the least practicable adverse impact on the species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of the species or stocks for subsistence uses (latter not 
applicable for this action). NMFS regulations require applicants for 
incidental take authorizations to include information about the 
availability and feasibility (economic and technological) of equipment, 
methods, and manner of conducting the activity or other means of 
effecting the least practicable adverse impact upon the affected 
species or stocks, and their habitat (50 CFR 216.104(a)(11)). The NDAA 
for FY 2004 amended the MMPA as it relates to military readiness 
activities and the incidental take authorization process such that 
``least practicable impact'' shall include consideration of personnel 
safety, practicality of implementation, and impact on the effectiveness 
of the military readiness activity.
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.

Assessment of Mitigation Measures for the EGTTR

    Section 216.104(a)(11) of NMFS' implementing regulations requires 
an applicant for incidental take authorization to include in its 
request, among other things, ``the availability and feasibility 
(economic and technological) of equipment, methods, and manner of 
conducting such activity or other means of effecting the least 
practicable adverse impact upon the affected species or stocks, their 
habitat, and [where applicable] on their availability for subsistence 
uses, paying particular attention to rookeries, mating grounds, and 
areas of similar significance.'' Thus, NMFS' analysis of the 
sufficiency and appropriateness of an applicant's measures under the 
least practicable adverse impact standard will always begin with 
evaluation of the mitigation measures presented in the application.
    NMFS has fully reviewed the specified activities and the mitigation 
measures included in the USAF's rulemaking/LOA application and the 
EGTTR 2022 REA to determine if the mitigation measures would result in 
the least practicable adverse impact on marine mammals and their 
habitat. The USAF would be required to implement the mitigation 
measures identified in this rule for the full 7 years to avoid or 
reduce potential impacts from proposed training and testing activities.
    Monitoring and mitigation measures for protected species are 
implemented for all EGTTR missions that involve the use of live or 
inert munitions (i.e., missiles, bombs, and gun ammunition). Mitigation 
includes operational measures such as pre-mission monitoring, 
postponement, relocation, or cancellation of operations, to minimize 
the exposures of all marine mammals to pressure waves and acoustic 
impacts as well as vessel strike avoidance measures to minimize the 
potential for ship strikes; geographic mitigation measures, such as 
setbacks and areas where mission activity is prohibited, to minimize 
impacts in areas used by Rice's whales; gunnery-specific mitigation 
measures which dictate how and where gunnery operations occur; and 
environmental mitigation which describes when missions may occur and 
under what weather conditions. These measures are supported by the use 
of PSOs from various platforms, and sea state restrictions. 
Identification and observation of appropriate mitigation zones (i.e. 
double the threshold distance at which Level A harassment exposures in 
the form of PTS could occur) and monitoring zones (i.e., area between 
the mitigation zone and the human safety zone perimeter) are important 
components of an effective mitigation plan.

Operational Measures

Pre-Mission Surveys
    Pre-mission surveys for protected species are conducted prior to 
every mission (i.e., missiles, bombs, and gunnery) in order to verify 
that the mitigation zone is free of visually detectable marine mammals 
and to evaluate the mission site for environmental suitability. USAF 
range-clearing vessels and protected species survey vessels holding 
PSOs will be onsite approximately 90 minutes prior to the mission. The 
duration of pre-mission surveys depends on the area required to be 
surveyed, the type of survey platforms used (i.e., vessels, aircraft, 
video), and any potential lapse in time between the end of the surveys 
and the beginning of the mission. Depending on the mission category, 
vessel-based PSOs will survey the mitigation and/or monitoring zones 
for marine mammals. Surveys of the mitigation zone will continue for 
approximately 30 minutes or until the entire mitigation zone has been 
adequately surveyed, whichever comes first. The mitigation zone survey 
area is defined by the area covered by double the dolphin Level A 
harassment (PTS) threshold distances predicted for the mission-day 
categories as presented previously in Table 27 and Table 28. Each user 
group will identify the mission-day category that best corresponds to 
its actual mission based on the energy that would be released. The user 
group will estimate the NEWi of the actual mission to identify which 
mission-day category to use. The energy of the actual mission will be 
less than the energy of the mission-day category in terms of total NEWi 
and largest single munition NEWi to ensure that the energy and effects 
of the actual mission will not exceed the energy and effects estimated 
for the corresponding mission-day category. For any live mission other 
than gunnery missions, the pre-mission survey mitigation zone will 
extend out to, at a minimum, double the Level A harassment PTS 
threshold distance that applies to both dolphin species. Depending on 
the mission-day category that best corresponds to the actual mission, 
the distance from the detonation point to the mitigation zone (i.e., 
double the Level A harassment (PTS) threshold distance) could vary 
between approximately 1,356 m for mission-day category J and 272 m for 
mission-day category I (Table 36). Surveying twice the dolphin Level A 
harassment (PTS) threshold distance provides a buffer area for when 
there is a lapse between the time when the survey ends and the

[[Page 8182]]

time when the species observers reach the perimeter of the human safety 
zone before the start of the mission. Surveying this additional buffer 
area ensures that dolphins are not within the PTS zone at the start of 
the mission. Missions involving air-to-surface gunnery operations must 
conduct surveys of even larger areas based on previously established 
safety profiles and the ability to conduct aerial surveys of large 
areas from the types of aircraft used for these missions.
    The monitoring zone for non-gunnery missions is the area between 
the mitigation zone and the human safety zone and is not standardized, 
since the size of the human safety zone is not standardized. The safety 
zone will be determined per each mission by the Eglin AFB Test Wing 
Safety Office based on the munition and parameters of its release (to 
include altitude, pitch, heading, and airspeed). Additionally, based on 
the operational altitudes of gunnery firing, and the fact that the only 
monitoring during the mission will be coming from onboard the aircraft 
conducting the live firing, the monitoring zone for gunnery missions 
will be a smaller area than the mitigation zone and will be based on 
the field of view from the aircraft. These observable areas will at 
least be double the Level A harassment (PTS) threshold distance for the 
mission-day categories G, H, and Q (gunnery-only mission-day 
categories) as shown in Table 36.

 Table 36--Mitigation and Monitoring Zone Sizes for Live Missions in the
                      Existing Live Impact Area (m)
------------------------------------------------------------------------
                                    Mitigation zone
      Mission-day category             (m)/(ft)         Monitoring zone
------------------------------------------------------------------------
A...............................  1,130 (3,706.4)...  TBD
B...............................  1,170 (3,837.6)...  TBD
C...............................  1,090 (3,575.2)...  TBD
D...............................  950 (3,116).......  TBD
E...............................  950 (3,116).......  TBD
F...............................  710 (2,328).......  TBD
G...............................  \1\ 9,260           550 (1,804)
                                   (30.372.8).
H...............................  \2\ 9,260           450 (1,476)
                                   (30,372.8).
I...............................  280 (918.4).......  TBD
J...............................  1,360 (4,460.8)...  TBD
K...............................  520 (1,705.6).....  TBD
L...............................  700 (2,296).......  TBD
M...............................  580 (1,640).......  TBD
N...............................  500 (1,640).......  TBD
O...............................  370 (1,213.6).....  TBD
P...............................  410 (1,344.8).....  TBD
Q...............................  \3\ 9,260           490 (1,607)
                                   (30,372.6).
R...............................  \4\ 280 (918.4)     TBD
                                   and 9,260
                                   (30372.8).
S...............................  860 (2,820.8).....  TBD
------------------------------------------------------------------------
 \1\ For G, double the Level A harassment threshold distance (PTS) is
  0.548 km, but G is AC-130 gunnery mission with an inherent mitigation
  zone of 9.260 km/5 NMI.
 \2\ For H, double the Level A harassment (PTS) threshold distance is
  0.450 km, but H is AC-130 gunnery mission with an inherent mitigation
  zone of 9.260 km/5 nmi.
 \3\ For Q, double the Level A harassment (PTS) threshold distance is
  0.494 km, but Q is AC-130 gunnery mission with an inherent mitigation
  zone of 9.260 km/5 nmi.
 \4\ R has components of both gunnery and inert small diameter bomb.
  Double the Level A harassment (PTS) threshold distance is 0.278 km,
  however, for gunnery component the inherent mitigation zone would be
  9.260 km.
 \5\ The Monitoring Zone for non-gunnery missions is the area between
  the Mitigation Zone and the Human Safety Zone and is not standardized,
  as the Human Safety Zone is not standardized. HSZ is determined per
  each mission by the Test Wing Safety Office based on the munition and
  parameters of its release (to include altitude, pitch, heading, and
  airspeed).
 \6\ Based on the operational altitudes of gunnery firing, and the only
  monitoring during mission coming from onboard the aircraft conducting
  the firing, the Monitoring Zone for gunnery missions will be a smaller
  area than the Mitigation Zone and be based on the field of view from
  the aircraft. These observable areas will at least be double the Level
  A harassment (PTS) threshold distance for the mission-day categories
  G, H, and Q (gunnery-only mission-day categories).

    For non-gunnery inert missions, the mitigation zone is based on 
double the Level A harassment (PTS) threshold distance as shown in 
Table 37. The monitoring zone is the area between the mitigation zone 
and the human safety zone which is not standardized. The safety zone is 
determined per each mission by the Test Wing Safety Office based on the 
munition and parameters of its release including altitude, pitch, 
heading, and airspeed.

 Table 37--Pre-mission Mitigation and Monitoring Zones (in m) for Inert
                          Missions Impact Area
------------------------------------------------------------------------
                                            Mitigation      Monitoring
      Inert impact class (lb TNTeq)         zone m/(ft)      zone \1\
------------------------------------------------------------------------
2.......................................       160 (524)             TBD
1.......................................       126 (413)             TBD
0.5.....................................       100 (328)             TBD
0.15....................................        68 (223)             TBD
------------------------------------------------------------------------
\1\ The Monitoring Zone for non-gunnery missions is the area between the
  Mitigation Zone and the Human Safety Zone and is not standardized, as
  the Human Safety Zone is not standardized. HSZ is determined per each
  mission by the Test Wing Safety Office based on the munition and
  parameters of its release (to include altitude, pitch, heading, and
  airspeed).

    Mission postponement, relocation, or cancellation--Mission 
postponement, relocation, or cancellation would be required when marine 
mammals are observed within the mitigation or monitoring zone depending 
on the mission type to minimize the potential for marine mammals to be 
exposed to injurious levels of pressure and noise energy from live 
detonations. If one or more marine mammal species other than the two 
dolphin species for which take is proposed to be authorized are 
detected in either the mitigation zone or the monitoring zone, then 
mission activities will be cancelled for the remainder of the day. The 
mission must be postponed, relocated or cancelled if either of the two 
dolphin species are

[[Page 8183]]

visually detected in the mitigation zone during the pre-mission survey. 
If members of the two dolphin species for which authorized take has 
been proposed are observed in the monitoring zone while vessels are 
exiting the human safety zone and the PSO has determined the animals 
are heading towards the mitigation zone, then missions will be 
postponed, relocated, or cancelled, based on mission-specific test and 
environmental parameters. Postponement would continue until the animals 
are confirmed to be outside of the mitigation zone on a heading away 
from the targets or are not seen again for 30 minutes and are presumed 
to be outside the mitigation zone. If large schools of fish or large 
flocks of birds are observed feeding at the surface are observed within 
the mitigation zone, postponement would continue until these potential 
indicators of marine mammal presence are confirmed to be outside the 
mitigation zone.
    Vessel strike avoidance measures--Vessel strike avoidance measures 
as previously advised by NMFS Southeast Regional Office must be 
employed by the USAF to minimize the potential for ship strikes. These 
measures include staying at least 150 ft (46 m) away from protected 
species and 300 ft (92 m) away from whales. Additional action area 
measures will require vessels to stay 500 m away from the Rice's whale. 
If a baleen whale cannot be positively identified to species level then 
it must be assumed to be a Rice's whale and 500 m separation distance 
must be maintained. Vessels must avoid transit in the Core Distribution 
Area (CDA) and within the 100-400 m isobath zone outside the CDA. If 
transit in these areas is unavoidable, vessels must not exceed 10 knots 
and transit at night is prohibited. An exception to the speed 
restriction is for instances required for human safety, such as when 
members of the public need to be intercepted to secure the human safety 
zone, or when the safety of a vessel operations crew could be 
compromised.

Geographic Mitigation Measures

Setbacks From Rice's Whale Habitat
    New mitigation measures that were not required as part of the 
existing LOA have been proposed to reduce impacts to the Rice's whale. 
These measures would require that given mission-day activities could 
only occur in areas that are exterior to and set back some specified 
distance from Rice's whale habitat boundaries as well as areas where 
mission activities are prohibited. These are described below.
    As a mitigation measure to prevent impacts to cetacean species 
known to occur in deeper portions of the Gulf of Mexico, such as the 
federally endangered sperm whale, all gunnery missions have been 
located landward of the 200-m isobath, which is generally considered to 
be the shelf break in the Gulf of Mexico. Most missions conducted over 
the last 5 years under the existing LOA have occurred in waters less 
than 100 m in depth. While implementing this measure would prevent 
impacts to most marine mammal species in the Gulf, it may not provide 
full protection to the Rice's whale, which has been documented to occur 
in waters as shallow as 117 m, although the majority of sightings have 
occurred in waters deeper than 200 m.
    To prevent any PTS impacts to the Rice's whale from gunnery 
operations, NMFS has proposed that all gunnery missions would be 
conducted at least 500 m landward of the 100-m isobath instead of 
landward of the 200-m isobath as was originally proposed by the USAF. 
This setback distance from the 100-m isobath is based on the modeled 
PTS threshold distance for daytime gunnery missions (mission-day G) of 
494 m (Table 29). At this setback distance, potential PTS effects from 
daytime gunnery missions would not extend into Rice's whale habitat, as 
defined by the 100-m isobath. The PTS Level A harassment isopleth of a 
nighttime gunnery mission, which is 401 m in radius, is contained 
farther landward of the habitat boundary.
    Another mitigation measure to prevent any PTS (or more severe) 
impacts to the Rice's whale will restrict the use of all live munitions 
in the western part of the existing LIA and proposed East LIA based on 
the setbacks from the 100-m isobaths. The setback distances determined 
for the mission-day categories are presented in Table 33 and are shown 
for the existing LIA and proposed East LIA on Figures 6-5 and 6-6, 
respectively. For example, the subsurface detonation of a GBU-10, GBU-
24, or GBU-31, each of which have a NEW of 945 lb (428.5 kg), would 
represent the most powerful single detonation that would be conducted 
under the USAF's proposed activities. Such a detonation would 
correspond to mission-day category J. To prevent any PTS impacts to the 
Rice's whale, a mission that would involve such a single subsurface 
detonation would be conducted in a portion of the LIA that is behind 
the setback identified for mission-day category J.
    Likewise, a mission that would involve multiple detonations that 
have a total cumulative NEWi comparable to that of mission-day category 
A would be conducted behind the setback identified for mission-day 
category A. Each user group will use the mission-day categories and 
corresponding setback distances to determine the setback distance that 
is appropriate for their actual mission. The user group will estimate 
the NEWi of the actual mission to identify which mission-day category 
and associated setback to use. The energy of the actual mission must be 
less than the energy of the mission-day category in terms of total NEWi 
and largest single-munition NEWi to ensure that the energy and effects 
of the actual mission will not exceed the energy and effects estimated 
for the corresponding mission-day category.
Rice's Whale Habitat Area Prohibitions
    This section identifies areas where firing of live or inert 
munitions is prohibited to limit impacts to Rice's whales. The USAF 
will prohibit the use of live or inert munitions in Rice's whale 
habitat during the effective period for the proposed LOA. Under this 
new mitigation measure, all munitions use will be prohibited between 
the 100-m and 400-m isobaths which represents the area where most 
Rice's whale detections have occurred. Live HACMs would be permitted to 
be fired into the existing LIA or East LIA but must have a setback of 
1.338 km from the 100-m isobath while inert HACMs could be fired into 
portions of the EGTTR outside the LIAs. However, they would need to be 
outside the area between the 100-m and 400-m isobaths.
    Overall, the USAF has agreed to procedural mitigation measures that 
would reduce the probability and/or severity of impacts expected to 
result from acute exposure to live explosives and inert munitions and 
impacts to marine mammal habitat.
Gunnery-Specific Mitigation
    Additional mitigation measures are applicable only to gunnery 
missions. The USAF must use 105 mm Training Rounds (TR; NEW of 0.35 lb 
(0.16 kg)) for nighttime missions. These rounds contain less explosive 
material content than the 105 mm Full Up (FU; NEW of 4.7 lb (2.16 kg)) 
rounds that are used during the day. Therefore, the harassment zones 
associates with the 105 mm TR are smaller and can be more effectively 
monitored compared to the daytime zones. Ramp-up procedures will also 
be required for day and night gunnery missions which must begin firing 
with the smallest round and proceed to increasingly larger rounds. The 
purpose of this measure is to expose the marine environment to

[[Page 8184]]

steadily increasing noise levels with the intent that marine animals 
will move away from the area before noise levels increase. During each 
gunnery training mission, gun firing can last up to 90 minutes but 
typically lasts approximately 30 minutes. Live firing is continuous, 
with pauses usually lasting well under 1 minute and rarely up to 5 
minutes. Aircrews must reinitiate protected species surveys if gunnery 
firing pauses last longer than 10 minutes.
    Protected species monitoring procedures for CV-22 gunnery training 
are similar to those described for AC-130 gunnery training, except that 
CV-22 aircraft typically operate at much lower altitudes than AC-130 
gunships. If protected marine species are detected during pre-mission 
surveys or during the mission, operations will be immediately halted 
until the monitoring zone is clear of all animals, or the mission will 
be relocated to another target area. If the mission is relocated, the 
pre-mission survey procedures will be repeated in the new area. If 
multiple gunnery missions are conducted during the same flight, marine 
species monitoring will be conducted separately for each mission. 
Following each mission, aircrews will conduct a post- mission survey 
beginning at the operational altitude and continuing through an 
orbiting descent to the designated monitoring altitude.
    All gunnery missions must monitor a set distance depending on the 
aircraft type as show in Table 38. Pre-mission aerial surveys conducted 
by gunnery aircrews in AC-130s extend out 5 nmi (9,260 m) while CV-22 
aircraft would have a monitoring range of 3 nmi (5,556 m). The modeled 
distances for behavioral disturbance for gunnery daytime and nighttime 
missions are 12.9 km and 7.1 km, respectively. The behavioral 
disturbance zone is smaller at night due to the required use of less 
impactful training rounds (105-mm TR). Therefore, the aircrews are able 
to survey all of the behavioral disturbance for a nighttime gunnery 
mission but not for a daytime gunnery mission. The size of the 
monitoring areas are based on the monitoring and operational altitudes 
of each aircraft as well as previously established aircraft safety 
profiles.

                          Table 38--Monitoring Areas and Altitudes for Gunnery Missions
----------------------------------------------------------------------------------------------------------------
                                                                              Monitoring          Operational
            Aircraft                 Gunnery round      Monitoring area        altitude            altitude
----------------------------------------------------------------------------------------------------------------
AC-30 Gunship...................  30 mm; 105 mm (FU   5 nmi (9,260 m)...  6,000 feet (1,828   15,000 to 20,000
                                   and TR).                                m).                 feet (4572-6096
                                                                                               m).
CV-22 Osprey....................  .50 caliber.......  3 nmi (5,556 m)...  1,000 feet (305 m)  1,000 feet (305
                                                                                               m).
----------------------------------------------------------------------------------------------------------------

    Other than gunnery training, HACM tests are the only other EGTTR 
missions currently proposed to be conducted at nighttime during the 
2023-2030 period. HACM tests and any other missions that are actually 
conducted at nighttime during the mission period will be required to be 
supported by AC-130 aircraft with night-vision instrumentation or other 
platforms with comparable nighttime monitoring capabilities. For live 
HACM missions, the pre-mission survey area will extend out to, at a 
minimum, double the Level A harassment (PTS) threshold distance that 
applies to both dolphin species for a HACM test. A HACM test would 
correspond to mission-day category K, which is estimated to have a PTS 
threshold distance of 0.258 km. Therefore, the pre-mission survey for a 
HACM test would extend out to 0.52 km, at a minimum.
Environmental Conditions
    Sea State Conditions--Appropriate sea state conditions must exist 
for protected species monitoring to be effective. Wind speed and the 
associated roughness of the sea surface are key factors that influence 
the efficacy of PSO monitoring. Strong winds increase wave height and 
create whitecaps, both of which limit a PSO's ability to visually 
detect marine species at or near the surface. The sea state scale used 
for EGTTR pre-mission protected species surveys is presented in Table 
39. All missions will be postponed or rescheduled if conditions exceed 
sea state 4, which is defined as moderate breeze, breaking crests, 
numerous white caps, wind speed of 11 to 16 knots, and wave height of 
3.3 to 6 ft (1.0 to 1.8 m). PSOs will determine whether sea conditions 
are suitable for protective species monitoring.

 Table 39--Sea State Scale Used for EGTTR Pre-Mission Protected Species
                                 Surveys
------------------------------------------------------------------------
       Sea state number                      Sea conditions
------------------------------------------------------------------------
0............................  Flat, calm, no waves or ripples.
1............................  Light air, winds 1 to 2 knots; wave
                                height to 1 foot; ripples without
                                crests.
2............................  Light breeze, winds 3 to 6 knots; wave
                                height 1 to 2 feet; small wavelets,
                                crests not breaking.
3............................  Gentle breeze, winds 7 to 10 knots; wave
                                height 2 to 3.5 feet; large wavelets,
                                scattered whitecaps.
4............................  Moderate breeze, winds 11 to 16 knots;
                                wave height 3.5 to 6 feet; breaking
                                crests, numerous whitecaps.
5............................  Strong breeze, winds 17 to 21 knots; wave
                                height 6 to 10 feet; large waves, spray
                                possible.
------------------------------------------------------------------------

    Daylight Restrictions--Daylight and visibility restrictions are 
also implemented to ensure the effectiveness of protected species 
monitoring. All live missions except for nighttime gunnery and 
hypersonic weapon missions will occur no earlier than 2 hours after 
sunrise and no later than 2 hours before sunset to ensure adequate 
daylight for pre- and post-mission monitoring.

Mitigation Conclusions

    NMFS has carefully evaluated the USAF's proposed mitigation 
measures. Our evaluation of potential measures included consideration 
of the following factors in relation to one another: the manner in 
which, and the degree to which, the successful implementation of the 
mitigation measures is expected to reduce the likelihood and/or 
magnitude of adverse impacts to marine mammal species and their 
habitat; the proven or likely efficacy of the measures; and the 
practicability of the measures for applicant implementation, including 
consideration of personnel safety, practicality of implementation, and 
impact on the effectiveness of the military readiness activity.

[[Page 8185]]

    Based on our evaluation of the USAF's proposed measures including 
pre-mission surveys; mission postponements or cancellations if animals 
are observed in the mitigation or monitoring zones; Rice's whale 
setbacks; Rice's whale habitat prohibitions; gunnery-specific measures; 
and environmental measures, NMFS has preliminarily determined that 
these proposed mitigation measures are the appropriate means of 
effecting the least practicable adverse impact on the marine mammal 
species and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and considering 
specifically personnel safety, practicality of implementation, and 
impact on the effectiveness of the military readiness activity. 
Additionally, an adaptive management provision ensures that mitigation 
is regularly assessed and provides a mechanism to improve the 
mitigation, based on the factors above, through modification as 
appropriate.
    The proposed rule comment period provides the public an opportunity 
to submit recommendations, views, and/or concerns regarding the USAF's 
activities and the proposed mitigation measures. While NMFS has 
preliminarily determined that the USAF's proposed mitigation measures 
would effect the least practicable adverse impact on the affected 
species and their habitat, NMFS will consider all public comments to 
help inform our final determination. Consequently, the proposed 
mitigation measures may be refined, modified, removed, or added to 
prior to the issuance of the final rule, based on public comments 
received, and, as appropriate, analysis of additional potential 
mitigation measures.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present while 
conducting the activities. Effective reporting is critical both to 
compliance as well as to ensuring that the most value is obtained from 
the required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and,
     Mitigation and monitoring effectiveness.
    The USAF will require training for all PSOs who will utilize 
vessel-based, aerial-based, video-based platforms or some combination 
of these approaches depending on the requirements of the mission type 
as shown in Table 40. Specific PSO training requirements are described 
below.

PSO Training

    All personnel who conduct protected species monitoring are required 
to complete Eglin AFB's Marine Species Observer Training Course, which 
was developed in consultation with NMFS. The required PSO training 
covers applicable environmental laws and regulations, consequences of 
non-compliance, PSO roles and responsibilities, photographs and 
descriptions of protected species and indicators, survey methods, 
monitoring requirements, and reporting procedures. Any person who will 
serve as a PSO for a particular mission must have completed the 
training within a year prior to the mission. For missions that require 
multiple survey platforms to cover a large area, a Lead Biologist is 
designated to lead the monitoring and coordinate sighting information 
with the Eglin AFB Test Director (Test Director) or the Eglin AFB 
Safety Officer (Safety Officer).
    Note that all three monitoring platforms described in Table 40 are 
not needed for all missions. The use of the platforms for a given 
mission are evaluated based on mission logistics, public safety, and 
the effectiveness of the platform to monitor for protected species. 
Vessel and video monitoring are almost always used but aerial 
monitoring may not be used for some missions because it is not needed 
in addition to the vessel-based surveys that are conducted. Aerial 
monitoring is considered to be supplemental to vessel-based monitoring 
and is used only when needed, for example if not enough vessels are 
available or to provide coverage in areas farther offshore where using 
vessels may be more logistically difficult. Note that at least one of 
the monitoring platforms described in Table 40 must be used for every 
mission. In most instances, two or three of the monitoring platforms 
will be employed.

     Table 40--Monitoring Options Required to the Extent Practicable and Locations for Live Air-to-Surface Mission Proponents Operating in the EGTTR
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Monitoring platform                      Location
                                                                                 -----------------------------------------------------------------------
            User group               Mission-day category       Munition type       Aerial-     Vessel-     Video-                              Outside
                                                                                     based       based       based        LIA      East LIA      LIAs
--------------------------------------------------------------------------------------------------------------------------------------------------------
53 WEG............................  A                       Missile.............          x           x           x           x           x   ..........
                                    B                       Missile, Bomb.......          x           x           x           x           x   ..........
                                    C                       Missile.............          x           x           x           x           x   ..........
                                    D                       Missile.............          x           x           x           x           x   ..........
                                    E                       Missile, Bomb,                x           x           x           x           x   ..........
                                                             Rocket, Gun
                                                             Ammunition.
AFSOC.............................  F                       Bomb................          x           x           x           x           x   ..........

[[Page 8186]]

 
                                    G                       Gun Ammunition......          x   ..........  ..........          x           x           x
                                    H                       Gun Ammunition......          x   ..........  ..........          x           x           x
                                    I                       Rockets.............          x           x           x           x           x   ..........
96 OG.............................  J                       Bomb................          x           x           x           x           x   ..........
                                    K                       Hypersonic..........          x           x           x           x           x   ..........
                                    L                       Missile, Bomb.......          x           x           x           x           x   ..........
                                    M                       Bomb................          x           x           x           x           x   ..........
                                    N                       Missile, Bomb.......          x           x           x           x           x   ..........
                                    O                       Missile.............          x           x           x           x           x   ..........
                                    P                       Missile.............          x           x           x           x           x   ..........
                                    Q                       Gun Ammunition......          x   ..........  ..........          x           x   ..........
                                    R                       Bomb, Gun Ammunition          x   ..........  ..........          x           x   ..........
NAVSCOLOED........................  S                       Charge..............  ..........          x   ..........          x           x           x
--------------------------------------------------------------------------------------------------------------------------------------------------------

Monitoring Platforms

Vessel-Based Monitoring
    Pre-mission surveys conducted from vessels will typically begin at 
sunrise. Vessel-based monitoring is required for all mission-day 
categories except for gunnery missions. Trained marine species PSOs 
will use dedicated vessels to monitor for protected marine species and 
potential indicators during the pre-mission surveys. For missions that 
require multiple vessels to cover a large survey area, a Lead Biologist 
will be designated to coordinate all survey efforts, compile sighting 
information from the other vessels, serve as the point of contact 
between the survey vessels and Tower Control, and provide final 
recommendations to the Safety Officer/Test Director on the suitability 
of the mission site based on environmental conditions and survey 
results.
    Survey vessels will run predetermined line transects, or survey 
routes, that will provide sufficient coverage of the survey area. 
Monitoring will be conducted from the highest point feasible on the 
vessels. There will be at least two PSOs on each vessel, and they will 
each use professional-grade binoculars.
    All sighting information from pre-mission surveys will be 
communicated to the Lead Biologist on a predetermined radio channel to 
reduce overall radio chatter and potential confusion. After compiling 
all the sighting information from the other survey vessels, the Lead 
Biologist will inform Tower Control if the survey area is clear or not 
clear of protected species. If the area is not clear, the Lead 
Biologist will provide recommendations on whether the mission should be 
postponed or cancelled. For example, a mission postponement would be 
recommended if a protected species is in the mitigation zone but 
appears to be heading away from the mission area. The postponement 
would continue until the Lead Biologist has confirmed that the animals 
are no longer in the mitigation zone and are swimming away from the 
range. A mission cancellation could be recommended if one or more 
protected species are sighted in the mitigation zones and there is no 
indication that they would leave the area within a reasonable time 
frame. Tower Control will relay the Lead Biologist's recommendation to 
the Safety Officer. The Safety Officer and Test Director will 
collaborate regarding range conditions based on the information 
provided. Ultimately, the Safety Officer will have final authority on 
decisions regarding postponements and cancellations of missions.
Human Safety Zone Monitoring
    Established range clearance procedures are followed during all 
EGTTR missions for public safety. Prior to each mission, a human safety 
zone appropriate for the mission is established around the target area. 
The size of the human safety zone varies depending on the munition type 
and delivery method. A composite safety zone is often developed for 
missions that involve multiple munition types and delivery methods. A 
typical composite safety zone is octagon-shaped to make it easier to 
monitor by range clearing boats and easier to interpret by the public 
when it is overlaid on maps with latitude and longitude coordinates. 
The perimeter of a composite safety zone may extend out to 
approximately 15 miles (13 nmi) from the center of the zone and may be 
monitored by up to 25 range-clearing boats to ensure it is free of any 
non-participating vessels before and during the mission.

Air Force Support Vessels

    USAF support vessels will be operated by a combination of USAF and 
civil service/civilian personnel responsible for mission site/target 
setup and range-clearing activities. For each mission, USAF personnel 
will be within the mission area (on boats and the GRATV) well in 
advance of initial munitions use, typically around sunrise. While in 
the mission area, they will perform a variety of tasks, such as target 
preparation and equipment checks, and will also observe for marine 
mammals and indicators when possible. Any sightings would be relayed to 
the Lead Biologist.
    The Safety Officer, in cooperation with the CCF (Central Control 
Facility) and Tower Control, will coordinate and manage all range-
clearing efforts and will be in direct communication with the survey 
vessel team, typically through the Lead Biologist. All support vessels 
will be in radio contact with each other and with Tower Control. The 
Safety Officer will monitor all radio communications, and Tower Control 
will relay messages between the vessels and the Safety Officer. The 
Safety Officer and Tower Control will also be in constant contact with 
the Test Director throughout the mission to convey information on range 
clearance and marine species surveys. Final decisions regarding mission 
execution, including possible mission postponement or cancellation 
based on marine species sightings or civilian boat traffic, will be the 
responsibility of the Safety Officer, with concurrence from the Test 
Director.
Aerial-Based Monitoring
    Aircraft provide an excellent viewing platform for detecting marine 
mammals at or near the sea surface. Depending on the mission, the 
aerial survey team will consist of Eglin AFB Natural Resources

[[Page 8187]]

Office personnel or their designees aboard a non-mission aircraft or 
the mission aircrew who have completed the PSO training. The Eglin AFB 
Natural Resources Office has overall responsibility for implementing 
the natural resources management program and is the lead organization 
for monitoring compliance with applicable Federal, State, and local 
regulations. It reports to the installation command, the 96th Test 
Wing, via the Environmental Management Branch of the 96th Civil 
Engineer Group. All mission-day categories require aerial-based 
monitoring, assuming assets are available and when such monitoring does 
not interfere with testing and training parameters required by mission 
proponents. Note that gunnery mission aircraft must also serve as 
aerial-based monitoring platforms.
    For non-mission aircraft, the pilot will be instructed on marine 
species survey techniques and will be familiar with the protected 
species expected to occur in the area. One PSO in the aircraft will 
record data and relay information on species sightings, including the 
species (if possible), location, direction of movement, and number of 
animals, to the Lead Biologist. The aerial team will also look for 
potential indicators of protected species presence, such as large 
schools of fish and large, active groups of birds. Pilots will fly the 
aircraft so that the entire mitigation and monitoring zones (and a 
buffer, if required) are monitored. Marine species sightings from the 
aerial survey team will be compiled by the Lead Biologist and 
communicated to the Test Director or Safety Officer. Monitoring by non-
mission aircraft would be conducted only for certain missions, when the 
use of such aircraft is practicable based on other mission-related 
factors.
    Some mission aircraft have the capability to conduct aerial surveys 
for marine species immediately prior to releasing munitions. Mission 
aircraft used to conduct aerial surveys will be operated at reasonable 
and safe altitudes appropriate for visually scanning the sea surface 
and/or using onboard instrumentation to detect protected species. The 
primary mission aircraft that conduct aerial surveys for marine species 
are the AC-130 gunship and CV-22 Osprey used for gunnery operations.
    AC-130 gunnery training involves the use of 30 mm and 105 mm FU 
rounds during daytime and 30 mm and 105 mm TRs during nighttime. The TR 
variant (0.35 lb (0.15 kg) NEW) of the 105 mm HE round has less 
explosive material than the FU round (4.7 lb (2.13 kg) NEW). AC-130s 
are equipped with and required to use low-light electro-optical and 
infrared sensor systems that provide excellent night vision. Gunnery 
missions use the 105 mm TRs during nighttime missions as an additional 
mitigation measure for protected marine species. If a towed target is 
used, mission personnel will maintain the target in the center portion 
of the survey area to ensure gunnery impacts do not extend past the 
predetermined mitigation and monitoring zones. During the low-altitude 
orbits and climb, the aircrew will visually scan the sea surface for 
the presence of protected marine species. The visual survey will be 
conducted by the flight crew in the cockpit and personnel stationed in 
the tail observer bubble and starboard viewing window.
    After arriving at the mission site and before initiating gun 
firing, the aircraft would be required to fly at least two complete 
orbits around the target area out to the applicable monitoring zone at 
a minimum safe airspeed and appropriate monitoring altitude. If no 
protected species or indicators are detected, the aircraft will then 
ascend to an operational altitude while continuing to orbit the target 
area as it climbs. The initial orbits typically last approximately 10 
to 15 minutes. Monitoring for marine species and non-participating 
vessels continues throughout the mission. When aerial monitoring is 
conducted by aircraft, a minimum ceiling of 305 m (1,000 feet) and 
visibility of 5.6 km (3 nmi) are required for effective monitoring 
efforts and flight safety.
    Infrared systems are equally effective during day or night. 
Nighttime missions would be conducted by AC-130s that have been 
upgraded recently with MX-25D sensor systems, which provide superior 
night-vision capabilities relative to earlier sensor systems. CV-22 
training involves the use of only .50 caliber rounds, which do not 
contain explosive material and, therefore, do not detonate. Aircrews 
will conduct visual and instrumentation-based scans during the post-
mission survey as described for the pre-mission survey.
Video-Based Monitoring
    Video-based monitoring is conducted via transmission of live, high-
definition video feeds from the GRATV at the mission site to the CCF 
and is required on all mission-day categories except for gunnery 
missions. These video feeds can be used to remotely view the mission 
site to evaluate environmental conditions and monitor for marine 
species up to the time munitions are used. There are multiple sources 
of video that can be streamed to multiple monitors within the CCF. A 
PSO from Eglin Natural Resources will monitor the live video feeds 
transmitted to the CCF when practicable and will report any protected 
marine species sightings to the Safety Officer, who will also be at the 
CCF. Video monitoring can mitigate the lapse in time between the end of 
the pre-mission survey and the beginning of the mission.
    Four video cameras are typically operated on the GRATV for real-
time monitoring and data collection during the mission. All cameras 
have a zoom capability of up to at least a 300 mm equivalent. The 
cameras allow video PSOs to detect an item as small as 1 square foot 
(0.09 square m) up to 4,000 m away.
    Supplemental video monitoring must be used when practicable via 
additional aerial assets. Aerial assets with video monitoring 
capabilities include Eglin AFB's aerostat balloon and unmanned aerial 
vehicles (UAVs). These aerial assets support certain missions, for 
example by providing video of munition detonations and impacts; these 
assets are not used during all missions. The video feeds from these 
aerial assets can be used to monitor protected species; however, they 
would always be a supplemental form of monitoring that would be used 
only when available and practicable. Eglin AFB's aerostat balloon 
provides aerial imagery of weapon impacts and instrumentation relay. 
When used, it is tethered to a boat anchored near the GRATV. The 
balloon can be deployed to an altitude of up to 2,000 ft (607 m). It is 
equipped with a high-definition camera system that is remotely 
controlled to pivot and focus on a specific target or location within 
the mission site. The video feed from the camera system is transmitted 
to the CCF. Eglin AFB may also employ other assets such as 
intelligence, surveillance, and reconnaissance aircraft to provide 
real-time imagery or relay targeting pod videos from mission aircraft. 
UAVs may also be employed to provide aerial video surveillance. While 
each of these platforms may not be available for all missions, they 
typically can be used in combination with each other and with the GRATV 
cameras to supplement overall monitoring efforts. Even with a variety 
of platforms potentially available to supply video feeds to the CCF, 
the entirety of the mitigation and monitoring zones may not be visible 
for the entire duration of the mission. The targets and immediate 
surrounding areas will typically be in the field of view of the GRATV 
cameras, which will allow the PSO to detect any protected species that 
may enter the target area before weapon releases. The cameras

[[Page 8188]]

also allow the PSO to readily inspect the target area for any signs 
that animals were injured. If a protected marine species is detected on 
the live video, the weapon release can be stopped almost immediately 
because the video camera PSO is in direct contact with Test Director 
and Safety Officer at the CCF.
    The video camera PSO will have open lines of communication with the 
PSOs on vessels to facilitate real-time reporting of marine species 
sightings and other relevant information, such as the presence of non-
participating vessels near the human safety zone. Direct radio 
communication will be maintained between vessels, GRATV personnel, and 
Tower Control throughout the mission. The Safety Officer will monitor 
all radio communications from the CCF, and information between the 
Safety Officer and support vessels will be relayed via Tower Control.

Post-Mission Monitoring

    During post-mission monitoring, PSOs would survey the mission site 
for any dead or injured marine mammals. Vessels will move into the 
survey area from outside the safety zone and monitor for at least 30 
minutes, concentrating on the area down current of the test site. The 
duration of post-mission surveys is based on the survey platforms used 
and any potential time lapse between the last detonation and the 
beginning of the post-mission survey. This lapse typically occurs when 
survey vessels stationed on the perimeter of the human safety zone are 
required to wait until the range has been declared clear before they 
can begin the survey. Up to 10 USAF support vessels will spend several 
hours in this area collecting debris from damaged targets.
    All vessels will report any dead or injured marine mammals to the 
Lead Biologist. All marine mammal sightings during post-mission surveys 
are documented on report forms that are submitted to Eglin Natural 
Resources Office after the mission. The post-mission survey area will 
be the area covered in 30 minutes of observation in a direction down-
current from impact site or the actual pre-mission survey area, 
whichever is reached first.
    For gunnery missions, aircrews must conduct a post-mission surveys 
beginning at the operational altitude and continuing through an 
orbiting descent to the designated monitoring altitude. The descent 
will typically last approximately 3 to 5 minutes. The post-mission 
survey area will be the area covered in 30 minutes of observation in a 
direction down-current from impact site or the actual pre-mission 
survey area, whichever is reached first. Aircrews will conduct visual 
and instrumentation-based scans during the post-mission survey as 
described for the pre-mission survey.
    As agreed upon between the USAF and NMFS, the proposed mitigation 
monitoring measures presented in the Proposed Mitigation section focus 
on the protection and management of potentially affected marine 
mammals. A well-designed monitoring program can provide important 
feedback for validating assumptions made in analyses and allow for 
adaptive management of marine resources.

Adaptive Management

    NMFS may modify (including augment) the existing mitigation, 
monitoring, or reporting measures (after consulting with Eglin AFB 
regarding the practicability of the modifications) if doing so creates 
a reasonable likelihood of more effectively accomplishing the goals of 
the mitigation and monitoring measures for these regulations.
    Possible sources of data that could contribute to the decision to 
modify the mitigation, monitoring, or reporting measures in an LOA 
include: (1) Results from Eglin AFB's acoustic monitoring study; (2) 
results from monitoring during previous year(s); (3) results from other 
marine mammal and/or sound research or studies; and (4) any information 
that reveals marine mammals may have been taken in a manner, extent or 
number not authorized by these regulations or subsequent LOAs.
    If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
will publish a notice of proposed LOA in the Federal Register and 
solicit public comment. If, however, NMFS determines that an emergency 
exists that poses a significant risk to the well-being of the species 
or stocks of marine mammals in the Gulf of Mexico, an LOA may be 
modified without prior notice or opportunity for public comment. Notice 
would be published in the Federal Register within 30 days of the 
action.

Proposed Reporting

    Section 101(a)(5)(A) of the MMPA states that, in order to issue 
incidental take authorization for an activity, NMFS must set forth 
requirements pertaining to the monitoring and reporting of such taking. 
Effective reporting is critical both to compliance as well as to 
ensuring that the most value is obtained from the required monitoring.
    A summary annual report of marine mammal observations and mission 
activities must be submitted to the NMFS Southeast Regional Office and 
the NMFS Office of Protected Resources 90 days after completion of 
mission activities each year. A final report shall be prepared and 
submitted within 30 days following resolution of comments on the draft 
report from NMFS. This annual report must include the following 
information:
     Date, time and location of each mission including mission-
day category, general munition type, and specific munitions used;
     Complete description of the pre-mission and post-mission 
monitoring activities including type and location of monitoring 
platforms utilized (i.e., vessel-, aerial or video-based);
     Summary of mitigation measures employed including 
postponements, relocations, or cancellations of mission activity;
     Number, species, and any other relevant information 
regarding marine mammals observed and estimated exposed/taken during 
activities;
     Description of the observed behaviors (in both presence 
and absence of test activities);
     Environmental conditions when observations were made, 
including visibility, air temperature, clouds, wind speed, and swell 
height and direction;
     Assessment of the implementation and effectiveness of 
mitigation and monitoring measures; and
     PSO observation results as provided through the use of 
protected species observer report forms.
    A Final Comprehensive Report summarizing monitoring and mitigation 
activities over the 7-year LOA effective period must be submitted 90 
days after the completion of mission activities at the end of Year 7.
    If a dead or seriously injured marine mammal is found during post-
mission monitoring, the incident must be reported to the NMFS Office of 
Protected Resources, NMFS Southeast Region Marine Mammal Stranding 
Network, and the Florida Marine Mammal Stranding Network. In the 
unanticipated event that any cases of marine mammal mortality are 
judged to result from missions in the EGTTR at any time during the 
period covered by the LOA, this will be reported to NMFS Office of 
Protected Resources and the National Marine Fisheries Service's 
Southeast Regional Administrator. The report must include the following 
information:
    1. Time and date of the incident;
    2. Description of the incident;
    3. Environmental conditions (e.g., wind speed and direction, cloud 
cover, and visibility);

[[Page 8189]]

    4. Species identification or description of the animal(s) involved;
    5. Fate of the animal(s); and
    6. Photographs or video footage of the animal(s).
    Mission activities must not resume in the EGTTR until NMFS is able 
to review the circumstances of the prohibited take. If it is determined 
that the unauthorized take was caused by mission activities, NMFS will 
work with the USAF to determine what measures are necessary to minimize 
the likelihood of further prohibited take and ensure MMPA compliance. 
The USAF may not resume their activities until notified by NMFS.

Past Monitoring Results in the EGTTR

    Eglin AFB has submitted to NMFS annual reports that summarize the 
results of protected species surveys conducted for EGTTR missions. From 
2010 to 2021, Eglin AFB conducted 67 gunnery missions in the EGTTR. To 
date, there has been no evidence that marine mammals have been impacted 
from gunnery operations conducted in the EGTTR. The use of 
instrumentation on the AC-130 and CV-22 in pre-mission surveys has 
proven effective to ensure the mission site is clear of protected 
species prior to gun firing. Monitoring altitudes during pre-mission 
surveys for both the AC-130 and CV-22 are much lower than 15,000 ft 
(4,572 m); therefore, the instrumentation on these aircraft would be 
even more effective at detecting marine species than indicated by 
photographs. From 2013 to 2020, Eglin AFB conducted 25 live missions 
collectively under the Maritime Strike Operations and Maritime Weapons 
System Evaluation Program (WSEP) Operational Testing programs in the 
EGTTR. From 2016-2021, Eglin AFB conducted 16 live PSW (Precision 
Strike Weapon) missions in the EGTTR. Protected species monitoring for 
these past missions was conducted using a combination of vessel-based 
surveys and live video monitoring from the CCF, as described. Pre-
mission survey areas for Maritime WSEP and PSW missions were based on 
mission-day categories developed per NMFS's request to account for the 
accumulated energy from multiple detonations. Note that surveys 
conducted for the earlier Maritime Strike missions were based on 
thresholds determined for single detonations; however, these Maritime 
WSEP and PSW missions involved detonations of larger munitions. There 
has been no evidence of mortality, injury, or any other detectable 
adverse impact to any marine mammal from the Maritime Strike, Maritime 
WSEP, or WSEP missions conducted to date. Dolphins were sighted within 
the mitigation zone prior to ordnance delivery during some of these 
past missions. In these cases, the mission was postponed until the 
animals were confirmed to be outside the mitigation zone. Although 
monitoring during and following munitions use is limited to observable 
impacts within and in the vicinity of the mission area, the lack of any 
past evidence of any associated impacts on marine mammals is an 
indication that the monitoring and mitigation measures implemented for 
EGTTR operations are effective.
    Eglin AFB submitted annual reports required under the existing LOA 
from 2018-2021. Although marine mammals were sighted on a number of 
mission days, usually during pre-and post-mission surveys, Eglin AFB 
concluded that no marine mammal takes occurred as a result of any 
mission activities from 2018-2021. The annual monitoring reports are 
available at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-air-force-testing-and-training-activities-eglin-gulf-test.

Preliminary Analysis and Negligible Impact Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (i.e., population-
level effects) (50 CFR 216.103). An estimate of the number of takes 
alone is not enough information on which to base an impact 
determination. In considering how Level A harassment or Level B 
harassment factor into the negligible impact analysis, in addition to 
considering the number of estimated takes, NMFS considers other 
factors, such as the likely nature of any responses (e.g., intensity, 
duration), the context of any responses (e.g., critical reproductive 
time or location, migration), as well as effects on habitat, and the 
likely effectiveness of the mitigation. Consistent with the 1989 
preamble for NMFS' implementing regulations (54 FR 40338, September 29, 
1989), the impacts from other past and ongoing anthropogenic activities 
are incorporated into this analysis via their impacts on the baseline 
(e.g., as reflected in the regulatory status of the species, population 
size and growth rate where known).
    In the Estimated Take of Marine Mammals section of this proposed 
rule, we identified the subset of potential effects that are reasonably 
expected to occur and rise to the level of takes based on the methods 
described. The impact that any given take will have on an individual, 
and ultimately the species or stock, is dependent on many case-specific 
factors that need to be considered in the negligible impact analysis 
(e.g., the context of behavioral exposures such as duration or 
intensity of a disturbance, the health of impacted animals, the status 
of a species that incurs fitness-level impacts to individuals, etc.). 
For this proposed rule, we evaluated the likely impacts of the number 
of harassment takes reasonably expected to occur, and proposed for 
authorization, in the context of the specific circumstances surrounding 
these predicted takes. Last, we collectively evaluated this 
information, as well as other more taxa-specific information and 
mitigation measure effectiveness, to support our negligible impact 
conclusions for each species and stock.
    As explained in the Estimated Take of Marine Mammals section, no 
take by serious injury or mortality is proposed for authorization or 
anticipated to occur. Further, any Level A harassment would be expected 
to be in the form of PTS; no non-auditory injury is anticipated or 
authorized.
    The Specified Activities reflect maximum levels of training and 
testing activities. The Description of the Proposed Activity section 
describes annual activities. There may be some flexibility in the exact 
number of missions that may vary from year to year, but take totals 
will not exceed the maximum annual numbers or the 7-year totals 
indicated in Table 35. We base our analysis and negligible impact 
determination on the maximum number of takes that are reasonably 
expected to occur and that are proposed for authorization, although, as 
stated before, the number of takes are only a part of the analysis, 
which includes qualitative consideration of other contextual factors 
that influence the degree of impact of the takes on the affected 
individuals. To avoid repetition, in this Preliminary Analysis and 
Negligible Impact Determination section we provide some general 
analysis that applies to all the species and stocks listed in Table 35, 
given that some of the anticipated effects of the USAF's training and 
testing activities on marine mammals are expected to be relatively 
similar in nature. Next, we break up our analysis by species and stock, 
to provide more specific information related to the anticipated effects 
on individuals of that species and to discuss where there is 
information about the status or structure of any species that would 
lead to a

[[Page 8190]]

differing assessment of the effects on the species.
    The USAF's take request, which, as described above, is for 
harassment only, is based on its acoustic effects model. The model 
calculates sound energy propagation from explosive and inert munitions 
during training and testing activities in the EGTTR. The munitions 
proposed to be used by each military unit were grouped into mission-day 
categories so the acoustic impact analysis could be based on the total 
number of detonations conducted during a given mission to account for 
the accumulated energy from multiple detonations over a 24-hour period. 
A total of 19 mission-day categories were developed for the munitions 
proposed to be used. Using the dBSea underwater acoustic model and 
associated analyses, the threshold distances and harassment zones were 
estimated for each mission-day category for each marine mammal species. 
Takes were estimated based on the area of the harassment zones, 
predicted animal density, and annual number of events for each mission-
day category. To assess the potential impacts of inert munitions on 
marine mammals, the proposed inert munitions were categorized into four 
classes based on their impact energies, and the threshold distances for 
each class were modeled and calculated as described for the mission-day 
categories. Assumptions in the USAF model intentionally err on the side 
of overestimation. For example, the model conservatively assumes that 
(1) the water surface is flat (no waves) to allow for maximum energy 
reflectivity; (2) munitions striking targets confer all weapon energy 
into underwater acoustic energy; and (3) above or at surface explosions 
assume no energy losses from surface effects (e.g., venting which 
dissipates energy through the ejection of water and release of 
detonation gases into the atmosphere).
    Generally speaking, the USAF and NMFS anticipate more severe 
effects from takes resulting from exposure to higher received levels 
(though this is in no way a strictly linear relationship for behavioral 
effects throughout species, individuals, or circumstances) and less 
severe effects from takes resulting from exposure to lower received 
levels. However, there is also growing evidence of the importance of 
distance in predicting marine mammal behavioral response to sound--
i.e., sounds of a similar level emanating from a more distant source 
have been shown to be less likely to evoke a response of equal 
magnitude (DeRuiter 2012, Falcone et al. 2017). The estimated number of 
Level A harassment and Level B harassment takes does not necessarily 
equate to the number of individual animals the USAF expects to harass 
(which is likely slightly lower). Rather, the estimates are for the 
instances of take (i.e., exposures above the Level A harassment and 
Level B harassment threshold) that are anticipated to occur annually 
and over the 7-year period. Some of the enumerated instances of 
exposure could potentially represent exposures of the same individual 
marine mammal on different days, meaning that the number of individuals 
taken is less than the number of instances of take, but the nature of 
the activities in this rule (e.g., short duration, intermittent) and 
the distribution and behavior of marine mammals in the area do not 
suggest that any single marine mammal would likely be taken on more 
than a few days within a year. Further, any of these instances of take 
may represent either brief exposures (seconds) or, in some cases, 
several exposures within a day. Most explosives detonating at or near 
the surface have brief exposures lasting only a few milliseconds to 
minutes for the entire event. Explosive events may be a single event 
involving one explosion (single exposure) or a series of intermittent 
explosives (multiple explosives) occurring over the course of a day. 
Gunnery events, in some cases, may have longer durations of exposure to 
intermittent sound. In general, gunnery events can last intermittently 
up to 90 minutes total, but typically lasts approximately 30 minutes. 
Live firing is continuous, with pauses usually lasting well under 1 
minute and rarely up to 5 minutes.

Behavioral Disturbance

    Behavioral reactions from explosive sounds are likely to be similar 
to reactions studied for other impulsive sounds such as those produced 
by air guns. Impulsive signals, particularly at close range, have a 
rapid rise time and higher instantaneous peak pressure than other 
signal types, making them more likely to cause startle responses or 
avoidance responses. Most data has come from seismic surveys that occur 
over long durations (e.g., on the order of days to weeks), and 
typically utilize large multi-air gun arrays that fire repeatedly. 
While seismic air gun data provides the best available science for 
assessing behavioral responses to impulsive sounds (i.e., sounds from 
explosives) by marine mammals, it is likely that these responses 
represent a worst-case scenario compared to most USAF explosive noise 
sources, because the overall duration of exposure to a seismic airgun 
survey would be expected to be significantly longer than the exposure 
to sounds from any exercise using explosives.
    Take estimates alone do not provide information regarding the 
potential fitness or other biological consequences of the reactions on 
the affected individuals. NMFS therefore considers the available 
activity-specific, environmental, and species-specific information to 
determine the likely nature of the modeled behavioral responses and the 
potential fitness consequences for affected individuals.
    In the range of potential behavioral effects that might be expected 
to be part of a response that qualifies as an instance of Level B 
harassment by behavioral disturbance (which by nature of the way it is 
modeled/counted, occurs within one day), the less severe end might 
include exposure to comparatively lower levels of a sound, at a 
detectably greater distance from the animal, for a few or several 
minutes. A less severe exposure of this nature could result in a 
behavioral response such as avoiding an area that an animal would 
otherwise have chosen to move through or feed in for some amount of 
time or breaking off one or a few feeding bouts. More severe effects 
could occur when the animal gets close enough to the source to receive 
a comparatively higher level, or is exposed intermittently to different 
sources throughout a day. Such effects might result in an animal having 
a more severe flight response and leaving a larger area for a day or 
more or potentially losing feeding opportunities for a day. However, 
such severe behavioral effects are expected to occur infrequently since 
monitoring and mitigation requirements would limit exposures to marine 
mammals. Additionally, previous marine mammal monitoring efforts in the 
EGTTR over a number of years have not demonstrated any impacts on 
marine mammals.
    The majority of Level B harassment takes are expected to be in the 
form of milder responses (i.e., lower-level exposures that still rise 
to the level of take) of a generally shorter duration due to lower 
received levels that would occur at greater distances from the 
detonation site due to required monitoring and mitigation efforts. For 
example, the largest munitions (e.g. mission-day category A with 2,413 
lb (1.094.6 kg) NEWi) feature up to 10 intermittent explosions over 
several hours. However, it is likely that animals would not be present 
in the PTS or TTS zones due to mitigation efforts, and this activity 
would occur on only a single day per year. Gunnery missions may last 
continuously up to 90 minutes, but most will be less than 30 minutes 
and the NEWi of such missions (i.e., 191.6 to

[[Page 8191]]

61.1 lb (86.9 to 27.7 kg) are relatively small. We anticipate more 
severe effects from takes when animals are exposed to higher received 
levels or at closer proximity to the source. However, depending on the 
context of an exposure (e.g., depth, distance, if an animal is engaged 
in important behavior such as feeding), a behavioral response can vary 
across species and individuals within a species. Specifically, given a 
range of behavioral responses that may be classified as Level B 
harassment, to the degree that higher received levels are expected to 
result in more severe behavioral responses, only a smaller percentage 
of the anticipated Level B harassment from USAF activities would be 
expected to potentially result in more severe responses. To fully 
understand the likely impacts of the predicted/authorized take on an 
individual (i.e., what is the likelihood or degree of fitness impacts), 
one must look closely at the available contextual information presented 
above, such as the duration of likely exposures and the likely severity 
of the exposures (e.g., whether they will occur for a longer duration 
over sequential days or the comparative sound level that will be 
received). Ellison et al. (2012) and Moore and Barlow (2013), among 
others, emphasize the importance of context (e.g., behavioral state of 
the animals, distance from the sound source) in evaluating behavioral 
responses of marine mammals to acoustic sources.

Diel Cycle

    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Behavioral 
reactions to noise exposure (such as disruption of critical life 
functions, displacement, or avoidance of important habitat) are more 
likely to be significant for fitness if they last more than one diel 
cycle or recur on subsequent days (Southall et al. 2007). Consequently, 
a behavioral response lasting less than one day and not recurring on 
subsequent days is not considered particularly severe unless it could 
directly affect reproduction or survival (Southall et al. 2007). It is 
important to note the difference between behavioral reactions lasting 
or recurring over multiple days and anthropogenic activities lasting or 
recurring over multiple days (e.g., vessel traffic noise). The duration 
of USAF activities utilizing explosives vary by mission category and 
weapon type. There are a maximum of 230 mission days proposed in any 
given year, assuming every mission category utilizes all of their 
allotted mission days.
    Many mission days feature only a single or limited number of 
explosive munitions. Explosive detonations on such days would likely 
last only a few seconds. There are likely to be days or weeks that pass 
without mission activities. Because of their short activity duration 
and the fact that they are in the open ocean and animals can easily 
move away, it is similarly unlikely that animals would be exposed for 
long, continuous amounts of time, or repeatedly, or demonstrate 
sustained behavioral responses. All of these factors make it unlikely 
that individuals would be exposed to the exercise for extended periods 
or on consecutive days.

Temporary Threshold Shift

    NMFS and the USAF have estimated that some species and stocks of 
marine mammals may sustain some level of TTS from explosive 
detonations. In general, TTS can last from a few minutes to days, be of 
varying degree, and occur across various frequency bandwidths, all of 
which determine the severity of the impacts on the affected individual, 
which can range from minor to more severe. Explosives are generally 
referenced as broadband because of the various frequencies. Table 32 
indicates the number of takes by TTS that may be incurred by different 
species from exposure to explosives. The TTS sustained by an animal is 
primarily classified by three characteristics:
    1. Frequency--Available data (of mid-frequency hearing specialists 
exposed to mid- or high-frequency sounds; Southall et al., 2007) 
suggest that most TTS occurs in the frequency range of the source up to 
one octave higher than the source (with the maximum TTS at one-half 
octave above). TTS from explosives would be broadband.
    2. Degree of the shift (i.e., by how many dB the sensitivity of the 
hearing is reduced)--Generally, both the degree of TTS and the duration 
of TTS will be greater if the marine mammal is exposed to a higher 
level of energy (which would occur when the peak dB level is higher or 
the duration is longer). The threshold for the onset of TTS was 
discussed previously in this proposed rule. An animal would have to 
approach closer to the source or remain in the vicinity of the sound 
source appreciably longer to increase the received SEL. The sound 
resulting from an explosive detonation is considered an impulsive sound 
and shares important qualities (i.e., short duration and fast rise 
time) with other impulsive sounds such as those produced by air guns. 
Given the anticipated duration and levels of sound exposure, we would 
not expect marine mammals to incur more than relatively low levels of 
TTS (i.e., single digits of sensitivity loss).
    3. Duration of TTS (recovery time)--In the TTS laboratory studies 
(as discussed in the Potential Effects of Specified Activities on 
Marine Mammals and their Habitat section of the proposed rule), some 
using exposures of almost an hour in duration or up to 217 SEL, almost 
all individuals recovered within 1 day (or less, often in minutes), 
although in one study (Finneran et al. 2007) recovery took 4 days. For 
the same reasons discussed in the Preliminary Analysis and Negligible 
Impact Determination - Diel Cycle section, and because of the short 
distance animals would need to be from the sound source, it is unlikely 
that animals would be exposed to the levels necessary to induce TTS in 
subsequent time periods such that their recovery is impeded.
    The TTS takes would be the result of exposure to explosive 
detonations (broad-band). As described above, we expect the majority of 
these takes to be in the form of mild (single-digit), short-term 
(minutes to hours) TTS. This means that for one time a year, for 
several minutes, a taken individual will have slightly diminished 
hearing sensitivity (slightly more than natural variation, but nowhere 
near total deafness). The expected results of any one of these small 
number of mild TTS occurrences could be that (1) it does not overlap 
signals that are pertinent to that animal in the given time period, (2) 
it overlaps parts of signals that are important to the animal, but not 
in a manner that impairs interpretation, or (3) it reduces 
detectability of an important signal to a small degree for a short 
amount of time--in which case the animal may be aware and be able to 
compensate (but there may be slight energetic cost), or the animal may 
have some reduced opportunities (e.g., to detect prey) or reduced 
capabilities to react with maximum effectiveness (e.g., to detect a 
predator or navigate optimally). However, given the small number of 
times that any individual might incur TTS, the low degree of TTS and 
the short anticipated duration, and the low likelihood that one of 
these instances would occur across a time period in which the specific 
TTS overlapped the entirety of a critical signal, it is unlikely that 
TTS of the nature expected to result from the USAF's activities would 
result in behavioral changes or other impacts that would impact any 
such individual's reproduction or survival.

[[Page 8192]]

Auditory Masking

    The ultimate potential impacts of masking on an individual (if it 
were to occur) are similar to those discussed for TTS, but an important 
difference is that masking only occurs during the time of the signal, 
versus TTS, which continues beyond the duration of the signal. 
Fundamentally, masking is referred to as a chronic effect because one 
of the key potential harmful components of masking is its duration--the 
fact that an animal would have reduced ability to hear or interpret 
critical cues becomes much more likely to cause a problem the longer it 
is occurring. Also inherent in the concept of masking is the fact that 
the potential for the effect is only present during the times that the 
animal and the source are in close enough proximity for the effect to 
occur (and further, this time period would need to coincide with a time 
that the animal was utilizing sounds at the masked frequency). As our 
analysis has indicated, because of the sound sources primarily involved 
in this rule, we do not expect the exposures with the potential for 
masking to be of a long duration. Masking is fundamentally more of a 
concern at lower frequencies, because low frequency signals propagate 
significantly further than higher frequencies and because they are more 
likely to overlap both the narrower low-frequency calls of mysticetes, 
as well as many non-communication cues, such as sounds from fish and 
invertebrate prey and geologic sounds that inform navigation. Masking 
is also more of a concern from continuous (versus intermittent) sources 
when there is no quiet time between a sound source within which 
auditory signals can be detected and interpreted. Explosions introduce 
low-frequency, broadband sounds into the environment, which could 
momentarily mask hearing thresholds in animals that are nearby, 
although sounds from missile and bomb explosions last for only a few 
seconds. Sound from gunnery ammunition, however, can last up to 90 
minutes, although a 30-minute duration is more typical. Masking due to 
these relatively short duration detonations would not be significant. 
Effects of masking are only present when the sound from the explosion 
is present, and the effect is over the moment the sound is no longer 
detectable. Therefore, short-term exposure to the predominantly 
intermittent or single explosions are not expected to result in a 
meaningful amount of masking. For the reasons described here, any 
limited masking that could potentially occur from explosives would be 
minor, short-term and intermittent. Long-term consequences from 
physiological stress due to the sound of explosives would not be 
expected. In conclusion, masking is more likely to occur in the 
presence of broadband, relatively continuous noise sources, such as 
from vessels; however, the duration of temporal and spatial overlap 
with any individual animal would not be expected to result in more than 
short-term, low impact masking that would not affect reproduction or 
survival of individuals.

Auditory Injury (Permanent Threshold Shift)

    Table 42 indicates the number of individuals of each species for 
which Level A harassment in the form of PTS resulting from exposure to 
or explosives is estimated to occur. The number of individuals to 
potentially incur PTS annually from explosives for each species ranges 
from 0 (Rice's whale) to 9 (bottlenose dolphin). As described 
previously, no species are expected to incur non-auditory injury from 
explosives.
    As discussed previously, the USAF utilizes aerial, vessel and video 
monitoring to detect marine mammals for mitigation implementation, 
which is not taken into account when estimating take by PTS. Therefore, 
NMFS expects that Level A harassment is unlikely to occur at the 
authorized numbers. However, since it is difficult to quantify the 
degree to which the mitigation and avoidance will reduce the number of 
animals that might incur Level A harassment, NMFS proposes to authorize 
take by Level A harassment at the numbers derived from the exposure 
model. These estimated Level A harassment take numbers represent the 
maximum number of instances in which marine mammals would be reasonably 
expected to incur PTS, and we have analyzed them accordingly. In 
relation to TTS, the likely consequences to the health of an individual 
that incurs PTS can range from mild to more serious depending upon the 
degree of PTS and the frequency band. Any PTS accrued as a result of 
exposure to USAF activities would be expected to be of a small amount 
due to required monitoring and mitigation measures. Permanent loss of 
some degree of hearing is a normal occurrence for older animals, and 
many animals are able to compensate for the shift, both in old age or 
at younger ages as the result of stressor exposure (Green et al. 1987; 
Houser et al. 2008; Ketten 2012). While a small loss of hearing 
sensitivity may include some degree of energetic costs for compensating 
or may mean some small loss of opportunities or detection capabilities, 
at the expected scale it would be unlikely to impact behaviors, 
opportunities, or detection capabilities to a degree that would 
interfere with reproductive success or survival of any individuals.

Physiological Stress Response

    Some of the lower level physiological stress responses (e.g., 
orientation or startle response, change in respiration, change in heart 
rate) discussed in the Potential Effects of Specified Activities on 
Marine Mammals and their Habitat would likely co-occur with the 
predicted harassments, although these responses are more difficult to 
detect and fewer data exist relating these responses to specific 
received levels of sound. However, we would not expect the USAF's 
generally short-term and intermittent activities to create conditions 
of long-term, continuous noise leading to long-term physiological 
stress responses in marine mammals that could affect reproduction or 
survival.

Table 41--Annual Estimated Takes by Level A and Level B Harassment for Marine Mammals in the EGTTR and the Number Indicating the Instances of Total Take
                                                           as a Percentage of Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Proposed annual take by Level A and Level B
                                                                            harassment                                                      Takes as a
            Common name                   Stock/DPS      ------------------------------------------------   Total take       Abundance     percentage of
                                                            Behavioral                                                      (2021 SARS)      abundance
                                                            disturbance         TTS             PTS
--------------------------------------------------------------------------------------------------------------------------------------------------------
Common bottlenose dolphin.........  Northern Gulf of                 817             319               9            1145          63,280             1.8
                                     Mexico Continental
                                     Shelf.
Atlantic spotted dolphin..........  Northern Gulf of                 100              39               1             140          21,506             0.6
                                     Mexico.

[[Page 8193]]

 
Rice's whale *....................  ....................               4               2               0               6              51            11.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
* ESA-listed species in EGTTR

Assessing the Number of Individuals Taken and the Likelihood of 
Repeated Takes

    The estimated takes by Level B harassment shown in Table 40 
represent instances of take, not the number of individuals taken (the 
much lower and less frequent takes by Level A harassment are far more 
likely to be associated with separate individuals). As described 
previously, USAF modeling uses the best available science to predict 
the instances of exposure above certain acoustic thresholds, which are 
quantified as harassment takes. However, these numbers from the model 
do not identify whether and when the enumerated instances occur to the 
same individual marine mammal on different days, or how any such 
repeated takes may impact those individuals. One method that NMFS can 
use to help better understand the overall scope of the impacts is to 
compare the total instances of take against the abundance of that 
species (or stock if applicable). For example, if there are 100 
estimated harassment takes in a population of 100, one can assume 
either that every individual will be exposed above acoustic thresholds 
in no more than 1 day, or that some smaller number will be exposed in 
one day but a few individuals will be exposed multiple days within a 
year and a few not exposed at all. Abundance percentage comparisons are 
less than 8 percent for all authorized species and stocks. This means 
that: (1) not all of the individuals will be taken, and many will not 
be taken at all; (2) barring specific circumstances suggesting repeated 
takes of individuals, the average or expected number of days taken for 
those individuals taken is one per year; and (3) we would not expect 
any individuals to be taken more than a few times in a year. There are 
often extended periods of days or even weeks between individual mission 
days, although a small number of mission-days may occur consecutively. 
Marine mammals proposed to be authorized for take in this area of the 
Gulf of Mexico have expansive ranges and are unlikely to congregate in 
a small area that would be subject to repeated mission-related 
exposures for an extended time.
    To assist in understanding what this analysis means, we clarify a 
few issues related to estimated takes and the analysis here. An 
individual that incurs PTS or TTS may sometimes, for example, also be 
subject to direct behavioral disturbance at the same time. As described 
above in this section, the degree of PTS, and the degree and duration 
of TTS, expected to be incurred from the USAF's activities are not 
expected to impact marine mammals such that their reproduction or 
survival could be affected. Similarly, data do not suggest that a 
single instance in which an animal incurs PTS or TTS and also has an 
additional direct behavioral response would result in impacts to 
reproduction or survival. Accordingly, in analyzing the numbers of 
takes and the likelihood of repeated and sequential takes, we consider 
all the types of take, so that individuals potentially experiencing 
both threshold shift and direct behavioral responses are appropriately 
considered. The number of Level A harassment takes by PTS are so low 
for dolphin species (and zero for Rice's whale) compared to abundance 
numbers that it is considered highly unlikely that any individual would 
be taken at those levels more than once.
    Occasional, milder behavioral reactions are unlikely to cause long-
term consequences for individual animals or populations, and even if 
some smaller subset of the takes are in the form of longer (several 
hours or a day) and more severe responses, if they are not expected to 
be repeated over sequential days, impacts to individual fitness are not 
anticipated. Nearly all studies and experts agree that infrequent 
exposures of a single day or less are unlikely to impact an 
individual's overall energy budget (Farmer et al. 2018; Harris et al. 
2017; NAS 2017; New et al. 2014; Southall et al. 2007; Villegas-Amtmann 
et al. 2015).

Impacts to Marine Mammal Habitat

    Any impacts to marine mammal habitat are expected to be relatively 
minor. Noise and pressure waves resulting from live weapon detonations 
are not likely to result in long-term physical alterations of the water 
column or ocean floor. These effects are not expected to substantially 
affect prey availability, are of limited duration, and are 
intermittent. Impacts to marine fish were analyzed in our Potential 
Effects of Specified Activities on Marine Mammals and their Habitat 
section as well as in the 2002 (REA)(USAF 2022). In the REA, it was 
determined that fish populations were unlikely to be affected and prey 
availability for marine mammals would not be impaired. Other factors 
related to EGTTR activities that could potentially affect marine mammal 
habitat include the introduction of metals, explosives and explosion 
by-products, other chemical materials, and debris into the water column 
and substrate due to the use of munitions and target vessels. However, 
the effects of each were analyzed in the REA and were determined to be 
not significant.

Species/Stock-Specific Analyses

    This section builds on the broader discussion above and brings 
together the discussion of the different types and amounts of take that 
different species are likely to incur, the applicable mitigation, and 
the status of the species to support the negligible impact 
determinations for each species. We have described (above in the 
Preliminary Analysis and Negligible Impact Determination section) the 
unlikelihood of any masking having effects that would impact the 
reproduction or survival of any of the individual marine mammals 
affected by the USAF's activities. We also described in the Potential 
Effects of Specified Activities on Marine Mammals and their Habitat 
section of the proposed rule the unlikelihood of any habitat impacts 
having effects that would impact the reproduction or survival of any of 
the individual marine mammals affected by the USAF's activities. There 
is no predicted non-auditory tissue damage from explosives for any 
species, and limited takes of dolphin species by PTS are predicted. 
Much of the discussion below focuses on the Level B harassment 
(behavioral disturbance and TTS) and the mitigation measures that

[[Page 8194]]

reduce the probability or severity of effects. Because there are 
species-specific considerations, these are discussed below where 
necessary.

Rice's Whale

    The Gulf of Mexico Bryde's whale was listed as an endangered 
subspecies under the ESA in 2019. NMFS revised the common and 
scientific name of the listed animal in 2021 to Rice's whale and 
classification to a separate species to reflect the new scientifically 
accepted taxonomy and nomenclature. NMFS has identified the core 
distribution area in the northern Gulf of Mexico where the Rice's whale 
is primarily found and, further, LaBreque et al. (2015) identify the 
area as a small and resident BIA. The Rice's whale has a very small 
estimated population size (51, Hayes et al. 2021) with limited 
distribution.
    NMFS is proposing to allow for the authorization of two annual 
takes of Rice's whale by Level B harassment in the form of TTS and four 
annual takes by Level B harassment in the form of behavioral 
disturbance. The implementation of the required mitigation is expected 
to minimize the severity of any behavioral disturbance and TTS of 
Rice's whales. When we look at the northern Gulf of Mexico where the 
USAF has been intensively training and testing with explosives in the 
EGTTR for a number of years, there are no data suggesting any long-term 
consequences to reproduction or survival rates of Rice's whale from 
explosives.
    Rice's whale will benefit from the mitigation measures proposed to 
limit impacts to the species. As a mitigation measure to prevent any 
PTS and limit TTS and behavioral impacts to the Rice's whale, the USAF 
will restrict the use of live munitions in the western part of each LIA 
based on the setbacks from the 100-m isobath presented earlier. The 
USAF will also prohibit the use of inert munitions in Rice's whale 
habitat (100-400 m depth) throughout the EGTTR. The less impactful 105 
mm Training Round must be used by the USAF for nighttime missions and 
all gunnery missions must be conducted 500 m landward of the 100-m 
isobath. Furthermore, depending on the mission category, vessel-based, 
aerial, or video feed monitoring would be required. Noise from 
explosions is broadband with most energy below a few hundred Hz; 
therefore, any reduction in hearing sensitivity from exposure to 
explosive sounds is likely to be broadband with effects predominantly 
at lower frequencies. The limited number of Rice's whales, estimated to 
be two animals, that do experience TTS from exposure to explosives may 
have reduced ability to detect biologically important sounds (e.g., 
social vocalizations). However, any TTS that would occur would be of 
short duration.
    Research and observations show that if mysticetes are exposed to 
impulsive sounds such as those from explosives, they may react in a 
variety of ways, which may include alerting, startling, breaking off 
feeding dives and surfacing, diving or swimming away, changing 
vocalization, or showing no response at all (DOD 2017; Nowacek 2007; 
Richardson 1995; Southall et al. 2007). Overall, and in consideration 
of the context for an exposure, mysticetes have been observed to be 
more reactive to acoustic disturbance when a noise source is located 
directly in their path or the source is nearby (somewhat independent of 
the sound level) (Dunlop et al. 2016; Dunlop et al. 2018; Ellison et 
al. 2011; Friedlaender et al. 2016; Henderson et al. 2019; Malme et al. 
1985; Richardson et al. 1995; Southall et al. 2007a). Animals disturbed 
while engaged in feeding or reproductive behaviors may be more likely 
to ignore or tolerate the disturbance and continue their natural 
behavior patterns. Because noise from most activities using explosives 
is short term and intermittent, and because detonations usually occur 
within a small area (most of which are set back from the primary area 
of Rice's whale use), behavioral reactions from Rice's whales, if they 
occur at all, are likely to be short term and of little to no 
significance.
    As described, the anticipated and proposed take of Rice's whale is 
of a low magnitude and severity that is not expected to impact the 
reproduction or survival of any individuals, much less population rates 
of recruitment or survival. Accordingly, we have found that the take 
allowable and proposed for authorization under the rule will have a 
negligible impact on Rice's whales.

Delphinids

    Neither the common bottlenose dolphin (Northern Gulf of Mexico 
continental shelf stock) or Atlantic spotted dolphin (Gulf of Mexico 
stock) are listed as strategic or depleted under the MMPA, and no 
active unusual mortality events (UME) have been declared. No mortality 
or non-auditory injury is predicted or proposed for authorization for 
either of these species. There are no areas of known biological 
significance for dolphins in the EGTTR. Repeated takes of the same 
individual animals would be unlikely. The number of PTS takes from the 
proposed activities are low (one for Atlantic spotted dolphin; nine for 
common bottlenose dolphin). Because of the low degree of PTS discussed 
previously (i.e., low amount of hearing sensitivity loss), it is 
unlikely to affect reproduction or survival of any individuals. 
Regarding the severity of individual takes by Level B harassment by 
behavioral disturbance, we have explained the duration of any exposure 
is expected to be between seconds and minutes (i.e., relatively short 
duration) and the severity of takes by TTS are expected to be low-
level, of short duration and not at a level that will impact 
reproduction or survival.
    As described, the anticipated and proposed take of dolphins is of a 
low magnitude and severity such that it is not expected to impact the 
reproduction or survival of any individuals, much less population rates 
of recruitment or survival. Accordingly, we have found that the take 
allowable and proposed for authorization under the rule will have a 
negligible impact on common bottlenose dolphins and Atlantic spotted 
dolphins.

Determination

    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, NMFS 
preliminarily finds that the total marine mammal take from the 
specified activities will have a negligible impact on all affected 
marine mammal species. In addition as described previously, the USAF's 
proposed implementation of monitoring and mitigation measures would 
further reduce impacts to marine mammals.

Unmitigable Adverse Impact Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
preliminarily determined that the total taking of affected species or 
stocks would not have an unmitigable adverse impact on the availability 
of the species or stocks for taking for subsistence purposes.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA, 16 
U.S.C. 1531 et seq.) requires that each Federal agency ensure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of LOAs, 
NMFS consults internally whenever we propose to authorize take for 
endangered or threatened species, in this case with the NMFS Office of

[[Page 8195]]

Protected Resources Interagency Cooperation Division.
    NMFS is proposing to authorize take of the Rice's whale, which is 
listed under the ESA. The Permits and Conservation Division has 
requested initiation of section 7 consultation with the Interagency 
Cooperation Division for the issuance of this proposed rule. NMFS will 
conclude the ESA consultation prior to reaching a determination 
regarding the proposed issuance of the authorization.

National Marine Sanctuaries Act

    NMFS will work with NOAA's Office of National Marine Sanctuaries to 
fulfill our responsibilities under the National Marine Sanctuaries Act 
as warranted and will complete any NMSA requirements prior to a 
determination on the issuance of the final rule and LOA.

Classification

Executive Order 12866

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

Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility Act (RFA), the Chief Counsel 
for Regulation of the Department of Commerce has certified to the Chief 
Counsel for Advocacy of the Small Business Administration that this 
proposed rule, if adopted, would not have a significant economic impact 
on a substantial number of small entities. The RFA requires Federal 
agencies to prepare an analysis of a rule's impact on small entities 
whenever the agency is required to publish a notice of proposed 
rulemaking. However, a Federal agency may certify, pursuant to 5 U.S.C. 
605(b), that the action will not have a significant economic impact on 
a substantial number of small entities. The USAF is the sole entity 
that would be affected by this rulemaking, and the USAF is not a small 
governmental jurisdiction, small organization, or small business, as 
defined by the RFA. Any requirements imposed by an LOA issued pursuant 
to these regulations, and any monitoring or reporting requirements 
imposed by these regulations, would be applicable only to the USAF. 
NMFS does not expect the issuance of these regulations or the 
associated LOA to result in any impacts to small entities pursuant to 
the RFA. Because this action, if adopted, would directly affect the 
USAF and not a small entity, NMFS concludes that the action would not 
result in a significant economic impact on a substantial number of 
small entities.

List of Subjects in 50 CFR Part 218

    Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine 
mammals, Penalties, Reporting and recordkeeping requirements, Seafood, 
Sonar, Transportation, USAF.

    Dated: January 30, 2023.
Samuel D. Rauch, III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.
    For the reasons set out in the preamble, NMFS proposes to amend 50 
CFR part 218 is proposed to be amended as follows:

PART 218--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE 
MAMMALS

0
1. The authority citation for part 218 continues to read as follows:

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

0
2. Revise subpart G to read as follows:

Subpart G--Taking and Importing Marine Mammals; U.S. Air Force's 
Eglin Gulf Test and Training Range (EGTTR)

Sec.
218.60 Specified activity and geographical region.
218.61 Effective dates.
218.62 Permissible methods of taking.
218.63 Prohibitions.
218.64 Mitigation requirements.
218.65 Requirements for monitoring and reporting.
218.66 Letters of Authorization.
218.67 Renewals and modifications of Letters of Authorization.
218.68 [Reserved]
218.69 [Reserved]


Sec.  218.60  Specified activity and geographical region.

    (a) Regulations in this subpart apply only to the U.S. Air Force 
(USAF) for the taking of marine mammals that occurs in the area 
described in paragraph (b) of this section and that occurs incidental 
to the activities listed in paragraph (c) of this section.
    (b) The taking of marine mammals by the USAF under this subpart may 
be authorized in a Letter of Authorization (LOA) only if it occurs 
within the Eglin Gulf Test and Training Range (EGTTR). The EGTTR is 
located adjacent to Santa Rosa, Okaloosa, and Walton Counties and 
includes property on Santa Rosa Island and Cape San Blas. The EGTTR is 
the airspace controlled by Eglin AFB over the Gulf of Mexico, beginning 
3 nautical miles (nmi) from shore, and the underlying Gulf of Mexico 
waters. The EGTTR extends southward and westward off the coast of 
Florida and encompasses approximately 102,000 square nautical miles 
(nmi\2\). It is subdivided into blocks of airspace that consist of 
Warning Areas W-155, W-151, W-470, W-168, and W-174 and Eglin Water 
Test Areas 1 through 6. The two primary components of the EGTTR Complex 
are Live Impact Area and East Live Impact Area.
    (c) The taking of marine mammals by the USAF is only authorized if 
it occurs incidental to the USAF conducting training and testing 
activities, including air warfare and surface warfare training and 
testing activities.


Sec.  218.61  Effective dates.

    Regulations in this subpart are effective for seven years from the 
date of issuance.


Sec.  218.62  Permissible methods of taking.

    (a) Under an LOA issued pursuant to Sec.  216.106 of this 
subchapter and Sec.  218.66, the Holder of the LOA (hereinafter 
``USAF'') may incidentally, but not intentionally, take marine mammals 
within the area described in Sec.  218.60(b) by Level A and Level B 
harassment associated training and testing activities described in 
Sec.  218.60(c) provided the activity is in compliance with all terms, 
conditions, and requirements of the regulations in this subpart and the 
applicable LOA.
    (b) The incidental take of marine mammals by the activities listed 
in Sec.  218.60(c) is limited to the species and stocks listed in Table 
1 of this section.

                                           Table 1 to Sec.   218.62(b)
----------------------------------------------------------------------------------------------------------------
               Common name                             Scientific name                          Stock
----------------------------------------------------------------------------------------------------------------
Atlantic spotted dolphin.................  Stenella frontalis.....................  Northern Gulf of Mexico.
Common Bottlenose dolphin................  Tursiops truncatus.....................  Northern Gulf of Mexico
                                                                                     Continental Shelf.
Rice's whale.............................  Balaenoptera ricei.....................  No Stock Designated.
----------------------------------------------------------------------------------------------------------------


[[Page 8196]]

Sec.  218.63  Prohibitions.

    Except for permissible incidental take described in Sec.  218.62 
and authorized by an LOA issued under Sec.  216.106 of this section and 
Sec.  218.66, no person in connection with the activities listed in 
Sec.  218.66 may do any of the following in connection with activities 
listed in Sec.  218.60(c):
    (a) Violate, or fail to comply with, the terms, conditions, or 
requirements of this subpart or an LOA issued under Sec.  216.106 of 
this section and Sec.  218.66;
    (b) Take any marine mammal not specified in Sec.  218.62(b);
    (c) Take any marine mammal specified in Sec.  218.62(b) in any 
manner other than as specified in the LOA issued under Sec.  216.106 of 
this subchapter and Sec.  218.66;
    (d) Take a marine mammal specified in Sec.  218.62(b) after NMFS 
determines such taking results in more than a negligible impact on the 
species or stock of such marine mammal.


Sec.  218.64  Mitigation requirements.

    When conducting the activities identified in Sec.  218.60(c), the 
mitigation measures contained in this part and any LOA issued under 
Sec.  216.106 of this subchapter and Sec.  218.66 must be implemented. 
These mitigation measures include, but are not limited to:
    (a) Operational measures. Operational mitigation is mitigation that 
the USAF must implement whenever and wherever an applicable training or 
testing activity takes place within the EGTTR for each mission-day 
category.
    (1) Pre-mission Survey.
    (i) All missions must occur during daylight hours with the 
exception of gunnery training and Hypersonic Active Cruise Missile 
(HACM) Tests, and other missions that can have nighttime monitoring 
capabilities comparable to the nighttime monitoring capabilities of 
gunnery aircraft.
    (ii) USAF range-clearing vessels and protected species survey 
vessels must be onsite 90 minutes before mission to clear prescribed 
human safety zone and survey the mitigation zone for the given mission-
day category.
    (iii) For all live missions except gunnery missions, USAF Protected 
Species Observers (PSOs) must monitor the mitigation zones as defined 
in Table 2 for the given mission-day category for a minimum of 30 
minutes or until the entirety of the mitigation zone has been surveyed, 
whichever comes first.
    (A) The mitigation zone for live munitions must be defined by the 
mission-day category that most closely corresponds to the actual 
planned mission based on the predicted net explosive weight at impact 
(NEWi) to be released, as shown in Table 2.
    (B) The mitigation zone for inert munitions must be defined by the 
energy class that most closely corresponds to the actual planned 
mission, as shown in Table 3.
    (C) The energy of the actual mission must be less than the energy 
of the identified mission-day category in terms of total NEWi as well 
as the largest single munition NEWi.
    (D) For any inert mission other than gunnery missions PSOs must at 
a minimum monitor out to the mitigation zone distances shown in Table 3 
that applies for the corresponding energy class.
    (E) Missions falling under mission-day categories A, B, C, and J, 
and all other missions when practicable must allot time to provide PSOs 
to vacate the human safety zone. While exiting, PSOs must observe the 
monitoring zone out to corresponding mission-day category as shown in 
Table 1 to Sec.  218.64(a)(1)(iv).
    (iv) For all missions except gunnery missions, PSOs and vessels 
must exit and remain outside the human safety zone designated by the 
USAF at least thirty minutes prior to live weapon deployment.

     Table 1 to Sec.   218.64(a)(1)(iv)--Pre-Mission Mitigation and
          Monitoring Zones (in m) for Live Missions Impact Area
------------------------------------------------------------------------
                                                              Monitoring
            Mission-day category               Mitigation      zone \5\
                                                  zone           \6\
------------------------------------------------------------------------
A..........................................           1,130          TBD
B..........................................           1,170          TBD
C..........................................           1,090          TBD
D..........................................             950          TBD
E..........................................             950          TBD
F..........................................             710          TBD
G..........................................       \1\ 9,260          550
H..........................................       \2\ 9,260          450
I..........................................             280          TBD
J..........................................           1,360          TBD
K..........................................             520          TBD
L..........................................             700          TBD
M..........................................             580          TBD
N..........................................             500          TBD
O..........................................             370          TBD
P..........................................             410          TBD
Q..........................................       \3\ 9,260          490
R..........................................     \4\ 280 and          TBD
                                                      9,260
S..........................................             860          TBD
------------------------------------------------------------------------
\1\ For G, double the Level A harassment threshold distance (PTS) is
  0.548 km, but G is AC-130 gunnery mission with an inherent mitigation
  zone of 9.260 km/5 nmi.
\2\ For H, double the Level A harassment threshold distance (PTS) is
  0.450 km, but H is AC-130 gunnery mission with an inherent mitigation
  zone of 9.260 km/5 nmi.
\3\ For Q, double the Level A harassment threshold distance (PTS) is
  0.494 km, but Q is AC-130 gunnery mission with an inherent mitigation
  zone of 9.260 km/5nmi.
\4\ R has components of both gunnery and inert small diameter bomb.
  Double the Level A harassment threshold distance (PTS) is 0.278 km,
  however, for gunnery component the inherent mitigation zone would be
  9.260 km.
\5\ The Monitoring Zone for non-gunnery missions is the area between the
  Mitigation Zone and the Human Safety Zone and is not standardized, as
  the Human Safety Zone is not standardized. The Human Safety Zone is
  determined per each mission by the Test Wing Safety Office based on
  the munition and parameters of its release (to include altitude,
  pitch, heading, and airspeed).
\6\ Based on the operational altitudes of gunnery firing, and the only
  monitoring during mission coming from onboard the aircraft conducting
  the firing, the Monitoring Zone for gunnery missions will be a smaller
  area than the Mitigation Zone and be based on the field of view from
  the aircraft. These observable areas will at least be double the Level
  A harassment threshold distance (PTS) for the mission-day categories
  G, H, and Q (gunnery-only mission-day categories).


     Table 2 to Sec.   218.64(a)(1)(iv)--Pre-Mission Mitigation and
         Monitoring Zones (in m) for Inert Missions Impact Area
------------------------------------------------------------------------
                                                 Mitigation   Monitoring
         Inert impact class (lb TNTeq)              zone       zone \1\
------------------------------------------------------------------------
2.............................................          160          TBD
1.............................................          126          TBD
0.5...........................................          100          TBD
0.15..........................................           68          TBD
------------------------------------------------------------------------
\1\ The Monitoring Zone for non-gunnery missions is the area between the
  Mitigation Zone and the Human Safety Zone and is not standardized, as
  the Human Safety Zone is not standardized. HSZ is determined per each
  mission by the Test Wing Safety Office based on the munition and
  parameters of its release (to include altitude, pitch, heading, and
  airspeed).


[[Page 8197]]

    (v) Missions involving air-to-surface gunnery operations must 
conduct aerial monitoring of the mitigation zones, as described in the 
Table 4.

     Table 3 to Sec.   218.64(a)(1)(v)--Aerial Monitoring Requirements for Air-to-Surface Gunnery Operations
----------------------------------------------------------------------------------------------------------------
        Aircraft              Gunnery round        Mitigation zone     Monitoring altitude  Operational altitude
----------------------------------------------------------------------------------------------------------------
AC-30 Gunship...........  30 mm; 105 mm (FU     5 nmi (9,260 m).....  6,000 ft (1,828 m)..  15,000 ft (4,572 m)
                           and TR).                                                          to 20,000 ft (6,096
                                                                                             m).
CV-22 Osprey............  .50 caliber.........  3 nmi (5,556 m).....  1,000 ft (3,280 m)..  1,000 ft (3,280 m).
----------------------------------------------------------------------------------------------------------------
FU = Full Up; TR = Training Round.

    (2) Mission postponement, relocation, or cancellation.
    (i) If marine mammals other than the two authorized dolphin species 
for which take is authorized are observed in either the mitigation zone 
or monitoring zone by PSOs, then mission activities must be cancelled 
for the remainder of the day.
    (ii) The mission must be postponed, relocated or cancelled if 
either of the two authorized dolphin species are visually detected in 
the mitigation zone during the pre-mission survey. Postponement must 
continue until the animals are confirmed to be outside of the 
mitigation zone and observed by a PSO to be heading away from the 
mitigation zone or until the animals are not seen again for 30 minutes.
    (iii) The mission must be postponed if marine mammal indicators 
(i.e., large schools of fish or large flocks of birds) are observed 
feeding at the surface within the mitigation zone. Postponement must 
continue until these potential indicators are confirmed to be outside 
the mitigation zone.
    (iv) If either of the two authorized dolphin species are observed 
in the monitoring zone by PSOs when observation vessels are exiting the 
human safety zone, and if PSOs determine the marine mammals are heading 
toward the mitigation zone, then missions must either be postponed, 
relocated, or cancelled based on mission-specific test and 
environmental parameters. Postponement must continue until the animals 
are confirmed by a PSO to be heading away from the mitigation zone or 
until the animals are not seen again for 30 minutes.
    (v) Aerial-based PSOs must look for potential indicators of 
protected species presence, such as large schools of fish and large, 
active groups of birds.
    (vi) If protected marine species or potential indicators are 
detected in the monitoring area during pre-mission surveys or during 
the mission by aerial-based or video-based PSOs, operations must be 
immediately halted until the mitigation zone is clear of all marine 
mammals, or the mission must be relocated to another target area.
    (3) Vessel avoidance measures.
    (i) Vessel operators must follow Vessel Strike Avoidance Measures.
    (A) When a marine mammal protected species is sighted, vessels must 
attempt to maintain a distance of at least 150 ft (46 m) away from 
protected species and 300 ft (92 m) away from whales. Vessels must 
reduce speed and avoid abrupt changes in direction until the animal(s) 
has left the area.
    (B) If a whale is sighted in a vessel's path or within 300 feet (92 
m) from the vessel, the vessel speed must be reduced and the vessel's 
engine must be shifted to neutral. The engines must not be engaged 
until the animals are clear of the area.
    (C) If a whale is sighted farther than 300 feet (92 m) from the 
vessel, the vessel must maintain a distance of 300 feet greater between 
the whale and the vessel's speed must be reduced to 10 knots or less.
    (D) Vessels are required to stay 500 m away from the Rice's whale. 
If a baleen whale cannot be positively identified to species level then 
it must be assumed to be a Rice's whale and the 500 m separation 
distance must be maintained.
    (E) Vessels must avoid transit in the Core Distribution Area (CDA) 
and within the 100-400 m isobath zone outside the CDA. If transit in 
these areas is unavoidable, vessels must not exceed 10 knots and 
transit at night is prohibited.
    (F) An exception to any vessel strike avoidance measure is for 
instances required for human safety, such as when members of the public 
need to be intercepted to secure the human safety zone, or when the 
safety of a vessel operations crew could be compromised.
    (4) Gunnery-specific Mitigation.
    (A) 105-mm training rounds (TR) must be used during nighttime 
gunnery missions.
    (B) Ramp-up procedures. Within a mission, firing must start with 
use of the lowest caliber munition and proceed to increasingly larger 
rounds.
    (C) Any pause in live fire activities greater than 10 minutes must 
be followed by the re-initiation of protected species surveys.
    (b) Geographic mitigation measures.
    (1) Use of live munitions is restricted in the western part of the 
existing LIA and proposed East LIA such that activities may not occur 
seaward of the setbacks from the 100 m-isobath shown in Table 5.

  Table 4 to Sec.   218.64(b)(1)--Setback Distances To Prevent Permanent Threshold Shift Impacts to the Rice's
                                                      Whale
----------------------------------------------------------------------------------------------------------------
                                                                                                   Setback from
                  User group                          Mission-day category           NEWi (lb)       100-meter
                                                                                                   isobath (km)
----------------------------------------------------------------------------------------------------------------
53 WEG.......................................  A                                         2,413.6           7.323
                                               B                                         2,029.9           6.659
                                               C                                         1,376.2           5.277
                                               D                                          836.22           3.557
                                               E                                           934.9           3.192
AFSOC........................................  F                                           584.6           3.169
                                               I                                            29.6           0.394
96 OG........................................  J                                           946.8           5.188
                                               K                                             350           1.338

[[Page 8198]]

 
                                               L                                           627.1           3.315
                                               M                                           324.9           2.017
                                               N                                           238.1           1.815
                                               O                                           104.6           0.734
                                               P                                           130.8           0.787
                                               Q                                            94.4           0.667
                                               R                                            37.1           0.368
NAVSCOLEOD...................................  S                                             130           1.042
----------------------------------------------------------------------------------------------------------------

    (2) All gunnery missions must be conducted at least 500 meters 
landward of the 100-m isobath.
    (3) Use of live munitions must be restricted to the LIA and East 
LIA and is prohibited from the area between the 100-m and 400-m 
isobaths.
    (4) Use of inert munitions is prohibited between the 100-m and 400-
m isobaths throughout the EGTTR.
    (5) Live Hypersonic Attack Cruise Missiles (HACMs) must be fired 
into the EGTTR inside of the LIAs and outside of the area between 100-m 
to 400-m isobaths
    (6) Live HACMs (Mission-day category K) must have a setback of 
1.338 km from the 100-m isobath.
    (7) Inert HACMs may be fired into portions of the EGTTR outside the 
LIAs but must be outside the area between the 100-m and 400-m isobaths.
    (4) Environmental mitigation.
    (i) Sea state conditions--Missions must be postponed or rescheduled 
if conditions exceed Beaufort sea state 4, which is defined as moderate 
breeze, breaking crests, numerous white caps, wind speed of 11 to 16 
knots, and wave height of 3.3 to 6 feet.
    (ii) Daylight Restrictions--All live missions except for nighttime 
gunnery and hypersonic weapon missions will occur no earlier than 2 
hours after sunrise and no later than 2 hours before sunset.


Sec.  218.65  Monitoring and Reporting

Requirements

    (a) PSO Training. All personnel who conduct protected species 
monitoring must complete Eglin Air Force Base's (AFB) Marine Species 
Observer Training Course.
    (1) Any person who will serve as a PSO for a particular mission 
must have completed the training within a year prior to the mission.
    (2) For missions that require multiple survey platforms to cover a 
large area, a Lead Biologist must be designated to lead the monitoring 
and coordinate sighting information with the Test Director or Safety 
Officer.
    (b) Vessel-based Monitoring.
    (1) Survey vessels must run predetermined line transects, or survey 
routes that will provide sufficient coverage of the survey area.
    (2) Monitoring must be conducted from the highest point feasible on 
the vessels.
    (3) There must be at least two PSOs on each survey vessel.
    (4) For missions that require multiple vessels to cover a large 
survey area, a Lead Biologist must be designated.
    (i) The Lead Biologist must coordinate all survey efforts.
    (ii) The Lead Biologist must compile sightings information from 
other vessels.
    (iii) The Lead Biologist must inform Tower Control if the 
mitigation and monitoring zones are clear or not clear of protected 
species.
    (iv) If the area is not clear, the Lead Biologist must provide 
recommendations on whether the mission should be postponed or canceled.
    (v) Tower Control must relay the Lead Biologist's recommendation to 
the Safety Officer. The Safety Officer and Test Director must 
collaborate regarding range conditions based on the information 
provided.
    (vi) The Safety Officer must have the final authority on decisions 
regarding postponements and cancellations of missions.
    (c) Aerial-based monitoring.
    (1) All mission-day categories require aerial-based monitoring, 
assuming assets are available and when such monitoring does not 
interfere with testing and training parameters required by mission 
proponents.
    (2) Gunnery mission aircraft must also serve as aerial-based 
monitoring platforms.
    (3) Aerial survey teams must consist of Eglin Natural Resources 
Office personnel or their designees aboard a non-mission aircraft or 
the mission aircrew.
    (4) All aircraft personnel on non-mission and mission aircraft who 
are acting in the role of a PSO must have completed Eglin AFB's Marine 
Species Observer Training course.
    (5) One trained PSO in the aircraft must record data and relay 
information on species sightings, including the species (if possible), 
location, direction of movement, and number of animals, to the Lead 
Biologist.
    (6) For gunnery missions, after arriving at the mission site and 
before initiating gun firing, the aircraft must fly at least two 
complete orbits around the target area out to the applicable monitoring 
zone at a minimum safe airspeed and appropriate monitoring altitude.
    (7) Aerial monitoring by aircraft must maintain a minimum ceiling 
of 305 m (1,000 feet) and visibility of 5.6 km (3 nmi) for effective 
monitoring efforts and flight safety as show in Table 5.
    (8) Pre-mission aerial surveys conducted by gunnery aircrews in AC-
130s must extend out 5 nmi (9,260 m) from the target location while 
aerial surveys in CV-22 aircraft must extend out from the target 
location to a range of 3 nmi (5,556 m) as shown in Table 4.
    (9) If the mission is relocated, the pre-mission survey procedures 
must be repeated in the new area.
    (10) If multiple gunnery missions are conducted during the same 
flight, marine species monitoring must be conducted separately for each 
mission;
    (11) During nighttime missions, night-vision goggles must be used.
    (12) During nighttime missions, low-light electro-optical and 
infrared sensor systems on board the aircraft must be used for 
protected species monitoring.
    (13) HACM tests and any other missions that are conducted at 
nighttime must be supported by AC-130 aircraft with night-vision 
instrumentation or other platforms with

[[Page 8199]]

comparable nighttime monitoring capabilities.
    (14) For HACM missions, the pre-mission survey area must extend out 
to, at a minimum, double the Level A harassment (PTS) threshold 
distance for delphinids (0.52 km). A HACM test would correspond to 
mission-day category K, which is estimated to have a PTS threshold 
distance of 0.26 km.
    (d) Video-based monitoring.
    (1) All mission-day categories require video-based monitoring when 
practicable except for gunnery missions.
    (2) A trained PSO (the video camera PSO) must monitor the live 
video feeds from the Gulf Range Armament Test Vessel (GRATV) 
transmitted to the Central Control Facility (CCF).
    (3) The video camera PSO must report any protected marine species 
sightings to the Safety Officer, who will also be at the CCF.
    (4) The video camera PSO must have open lines of communication with 
the PSOs on vessels to facilitate real-time reporting of marine species 
sightings.
    (5) Direct radio communication must be maintained between vessels, 
GRATV personnel, and Tower Control throughout the mission.
    (6) If a protected marine species is detected on the live video by 
a PSO prior to weapon release, the mission must be stopped immediately 
by the Safety Officer.
    (7) Supplemental video monitoring by additional aerial assets must 
be used when practicable (e.g., balloons, unmanned aerial vehicles).
    (e) Post-mission monitoring.
    (1) All marine mammal sightings must be documented on report forms 
that are submitted to the Eglin Natural Resources Office after the 
mission.
    (2) For gunnery missions, following each mission, aircrews must 
conduct a post-mission survey beginning at the operational altitude and 
continuing through an orbiting descent to the designated monitoring 
altitude. The post-mission survey area will be the area covered in 30 
minutes of observation in a direction down-current from the impact site 
or the actual pre-mission survey area, whichever is reached first.
    (3) During post-mission monitoring, PSOs must survey the mission 
site for any dead or injured marine mammals. The post-mission survey 
area will be the area covered in 30 minutes of observation in a 
direction down-current from the impact site or the actual pre-mission 
survey area, whichever is reached first.
    (f) The USAF must submit an annual draft monitoring report to NMFS 
within 90 working days of the completion of each year's activities 
authorized by the LOA as well as a comprehensive summary report at the 
end of the project. The annual reports and final comprehensive report 
must be prepared and submitted within 30 days following resolution of 
any NMFS comments on the draft report. If no comments are received from 
NMFS within 30 days of receipt of the draft report, the report will be 
considered final. If comments are received, a final report addressing 
NMFS comments must be submitted within 30 days after receipt of 
comments. The annual reports must contain the informational elements 
described below, at a minimum. The comprehensive 7-year report must 
include a summary of the monitoring information collected over the 7-
year period (including summary tables), along with a discussion of the 
practicability and effectiveness of the mitigation and monitoring and 
any other important observations or discoveries.
    (1) Dates and times (begin and end) of each EGTTR mission;
    (2) Complete description of mission activities;
    (3) Complete description of pre-and post-monitoring activities 
occurring during each mission;
    (4) Environmental conditions during monitoring periods including 
Beaufort sea state and any other relevant weather conditions such as 
cloud cover, fog, sun glare, and overall visibility to the horizon, and 
estimated observable distance;
    (5) Upon observation of a marine mammal, the following information 
should be collected:
    (i) Observer who sighted the animal and observer location and 
activity at time of sighting;
    (ii) Time of sighting;
    (iii) Identification of the animal (e.g., genus/species, lowest 
possible taxonomic level, or unidentified), observer confidence in 
identification, and the composition of the group if there is a mix of 
species;
    (iv) Distances and bearings of each marine mammal observed in 
relation to the target site;
    (v) Estimated number of animals including the minimum number, 
maximum number, and best estimate);
    (vi) Estimated number of animals by cohort (e.g., adults, 
juveniles, neonates, group composition etc.);
    (vii) Estimated time that the animal(s) spent within the mitigation 
and monitoring zones;
    (viii) Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling);
    (ix) Detailed information about implementation of any mitigation 
(e.g., postponements, relocations and cancellations), and
    (x) All PSO datasheets and/or raw sightings data.
    (6) The final comprehensive report must include a summary of data 
collected as part of the annual reports.
    (g) In the event that personnel involved in the monitoring 
activities discover an injured or dead marine mammal, the USAF must 
report the incident to NMFS Office of Protected Resources (OPR), and to 
the NMFS Southeast Region Marine Mammal Stranding Network Coordinator, 
as soon as feasible. If the death or injury was likely caused by the 
USAF's activity, the USAF must immediately cease the specified 
activities until NMFS OPR is able to review the circumstances of the 
incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of this rule and the 
LOA issued under Sec.  216.106 of this subchapter and Sec.  218.66.
    (1) The USAF will not resume their activities until notified by 
NMFS. The report must include the following information:
    (i) Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    (ii) Species identification (if known) or description of the 
animal(s) involved;
    (iii) Condition of the animal(s) (including carcass condition if 
the animal is dead);
    (iv) Observed behaviors of the animal(s), if alive;
    (v) If available, photographs or video footage of the animal(s); 
and
    (vi) General circumstances under which the animal was discovered.
    (2) [Reserved]


Sec.  218.66  Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to the regulations 
in this subpart, the USAF must apply for and obtain an LOA in 
accordance with Sec.  216.106 of this section.
    (b) An LOA, unless suspended or revoked, may be effective seven 
years from the date of issuance.
    (c) Except for changes made pursuant to the adaptive management 
provision of Sec.  218.67(b)(1), in the event of projected changes to 
the activity or to mitigation, monitoring, or reporting required by an 
LOA issued under this subpart, the USAF must apply for and obtain a 
modification of the LOA as described in Sec.  218.67.
    (d) Each LOA will set forth:
    (1) Permissible methods of incidental taking;

[[Page 8200]]

    (2) Geographic areas for incidental taking;
    (3) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species or stocks of marine mammals and their 
habitat; and
    (4) Requirements for monitoring and reporting.
    (e) Issuance of the LOA(s) must be based on a determination that 
the level of taking is consistent with the findings made for the total 
taking allowable under the regulations in this subpart.
    (f) Notice of issuance or denial of the LOA(s) will be published in 
the Federal Register within 30 days of a determination.


Sec.  218.67  Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec.  216.106 of this subchapter and Sec.  
218.66 for the activity identified in Sec.  218.60(c) may be modified 
upon request by the applicant, consistent with paragraph (b), provided 
that any requested changes to the activity or to the mitigation, 
monitoring, or reporting measures (excluding changes made pursuant to 
the adaptive management provision in paragraph (c)(1) of this section) 
do not change the underlying findings made for the regulations and do 
not result in more than a minor change in the total estimated number of 
takes (or distribution by species or years). NMFS may publish a notice 
of proposed LOA in the Federal Register, including the associated 
analysis of the change, and solicit public comment before issuing the 
LOA.
    (b) An LOA issued under Sec.  216.106 of this section and Sec.  
218.66 may be modified by NMFS under the following circumstances:
    (1) Adaptive management. After consulting with the USAF regarding 
the practicability of the modifications, NMFS may modify (including 
adding or removing measures) the existing mitigation, monitoring, or 
reporting measures if doing so creates a reasonable likelihood of more 
effectively accomplishing the goals of the mitigation and monitoring.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, or reporting measures in an LOA 
include:
    (A) Results from USAF's annual monitoring report and annual 
exercise report from the previous year(s);
    (B) Results from other marine mammal and/or sound research or 
studies;
    (C) Results from specific stranding investigations; or
    (D) Any information that reveals marine mammals may have been taken 
in a manner, extent, or number not authorized by the regulations in 
this subpart or subsequent LOAs.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
will publish a notice of a new proposed LOA in the Federal Register and 
solicit public comment.
    (2) Emergencies. If NMFS determines that an emergency exists that 
poses a significant risk to the well-being of the species of marine 
mammals specified in LOAs issued pursuant to Sec.  216.106 of this 
section and Sec.  218.66, an LOA may be modified without prior public 
notice or opportunity for public comment. Notice will be published in 
the Federal Register within thirty days of the action.


Sec.  218.68  [Reserved]


Sec.  218.69  [Reserved]

[FR Doc. 2023-02242 Filed 2-6-23; 8:45 am]
BILLING CODE 3510-22-P