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Rule2023-07939

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

Primary source

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Published

April 18, 2023

Effective

April 13, 2023

Issuing agencies

Commerce DepartmentNational Oceanic and Atmospheric Administration

Abstract

NMFS, upon request from the U.S. Department of the Air Force (USAF), issues these regulations pursuant to the Marine Mammal Protection Act (MMPA) to govern the taking of marine mammals incidental to testing and training activities to be conducted in the Eglin Gulf Test and Training Range (EGTTR) from 2023 to 2030 in the Gulf of Mexico. 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). These regulations, which allow for the issuance of Letters of Authorization (LOA) for the incidental take of marine mammals during the described activities and timeframes, prescribe the permissible methods of taking and other means of effecting the least practicable adverse impact on marine mammal species and their habitat, and establish requirements pertaining to the monitoring and reporting of such taking.

Full Text

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[Federal Register Volume 88, Number 74 (Tuesday, April 18, 2023)]
[Rules and Regulations]
[Pages 24058-24106]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-07939]

[[Page 24057]]

Vol. 88

Tuesday,

No. 74

April 18, 2023

Part IV

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; Final Rule

Federal Register / Vol. 88 , No. 74 / Tuesday, April 18, 2023 / Rules
and Regulations

[[Page 24058]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 230410-0096]
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: Final rule; notification of issuance of Letters of
Authorization.

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SUMMARY: NMFS, upon request from the U.S. Department of the Air Force
(USAF), issues these regulations pursuant to the Marine Mammal
Protection Act (MMPA) to govern the taking of marine mammals incidental
to testing and training activities to be conducted in the Eglin Gulf
Test and Training Range (EGTTR) from 2023 to 2030 in the Gulf of
Mexico. 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). These regulations, which allow
for the issuance of Letters of Authorization (LOA) for the incidental
take of marine mammals during the described activities and timeframes,
prescribe the permissible methods of taking and other means of
effecting the least practicable adverse impact on marine mammal species
and their habitat, and establish requirements pertaining to the
monitoring and reporting of such taking.

DATES:
Effective dates: Amendatory instruction 1 is effective April 13,
2023, and amendatory instruction 2 is effective from April 13, 2023,
through April 13, 2030.
Applicability dates: This rule is applicable to the USAF on April
13, 2023, through April 13, 2030.

ADDRESSES: A copy of the USAF's application, NMFS' proposed and final
rules and subsequent LOA for the existing regulations, and other
supporting documents and documents cited herein may be obtained online
at <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities">www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities</a>. 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 regulations, issued under the authority of the MMPA (16
U.S.C. 1361 et seq.), provide the framework for authorizing the take of
marine mammals incidental to the USAF's testing and training 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
will 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) will conduct operations in the existing
Live Impact Area (LIA). In addition, the USAF will also 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.
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
authorized.
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs
the Secretary of Commerce (as delegated to NMFS) to allow, upon
request, the incidental, but not intentional taking of small numbers of
marine mammals by U.S. citizens who engage in a specified activity
(other than commercial fishing) within a specified geographical region
if, after notice and public comment, the agency makes certain findings
and issues regulations that set forth permissible methods of taking
pursuant to that activity, as well as monitoring and reporting
requirements. Section 101(a)(5)(A) of the MMPA and the implementing
regulations at 50 CFR part 216, subpart I, provide the legal basis for
issuing this final rule and the subsequent LOAs. As directed by this
legal authority, this final rule contains mitigation, monitoring, and
reporting requirements.
The 2004 NDAA (Pub. L. 108-136) removed the ``small numbers'' and
``specified geographical region'' limitations indicated above and
amended the definition of ``harassment'' as applied to a ``military
readiness activity.'' The activity for which incidental take of marine
mammals is being requested addressed here qualifies as a 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.

Summary of Major Provisions Within the Final Rule

The following is a summary of the primary provisions of this final
rule regarding the USAF's activities. These provisions include, but are
not limited to:
<bullet> Use of live munitions with surface or subsurface
detonations is restricted to the existing Live Impact Area (LIA) and
the new East LIA;
<bullet> Use of live munitions in the western part of the existing
LIA and new East LIA is restricted based on specified setbacks from the
100-meter isobath. The 100-m isobath is the minimum depth at which the
majority of Rice's whale detections have occurred. The setbacks are
equivalent to the modeled threshold distances where each mission-day
category would cause the onset of permanent threshold shift (PTS) in
the Rice's whale;
<bullet> Use of inert munitions is prohibited between the 100-meter
to 400-meter isobaths throughout the EGTTR, which encompasses the area
in which the vast majority of Rice's whale detections have occurred;
<bullet> Gunnery missions must be conducted at least 500 meters
landward of the 100-meter isobath; and
<bullet> Use of 105 mm Training Rounds (TR) containing decreased
explosive material is required during live nighttime gunnery missions.
<bullet> Use of vessel-based, aerial-based and video-based
monitoring platforms for mission activities;

[[Page 24059]]

<bullet> Employment of protected species observers (PSOs) who have
completed Eglin's Marine Species Observer Training Course developed in
cooperation with NMFS;
<bullet> Implementing two passive acoustic monitoring (PAM) studies
(pending availability of funding); and
<bullet> Submission of annual and final comprehensive monitoring
reports that will record all occurrences of marine mammals and any
behavior or behavioral reactions observed, any observed incidents of
injury or behavioral harassment, and any required mission delays,
relocations or cancellations.
Additionally, the rule includes an adaptive management component
that allows for timely modification of mitigation or monitoring
measures based on new information, when appropriate.

Background

The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA direct the
Secretary of Commerce (as delegated to NMFS) to allow, upon request,
the incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, a notice of 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, including by Alaska Natives. 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 the species or stocks for taking for certain
subsistence uses (referred to in this rule as ``mitigation measures'');
and requirements pertaining to the monitoring and reporting of such
takings. The MMPA defines ``take'' to mean to harass, hunt, capture, or
kill, or attempt to harass, hunt, capture, or kill any marine mammal.
The Analysis and Negligible Impact Determination section below
discusses the definition of ``negligible impact.''
The NDAA for Fiscal Year 2004 (2004 NDAA) (Pub. L. 108-136) amended
section 101(a)(5) of the MMPA to remove the ``small numbers'' and
``specified geographical region'' provisions indicated above and
amended the definition of ``harassment'' as applied to a ``military
readiness activity.'' The definition of harassment for military
readiness activities (section 3(18)(B) of the MMPA) is (i) Any act that
injures or has the significant potential to injure a marine mammal or
marine mammal stock in the wild (Level A Harassment); or (ii) Any act
that disturbs or is likely to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of natural behavioral patterns,
including, but not limited to, migration, surfacing, nursing, breeding,
feeding, or sheltering, to a point where such behavioral patterns are
abandoned or significantly altered (Level B harassment). In addition,
the 2004 NDAA amended the MMPA as it relates to military readiness
activities such that 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.

Summary and Background 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
final rule. On February 7, 2023, we published a notice of proposed
rulemaking (88 FR 8146) and requested comments and information related
to the USAF's request for 30 days. All substantive comments received
during the NOR and the proposed rulemaking comment periods were
considered in developing this final rule. Comments received on the
proposed rule are addressed in this final rule in the Comments and
Responses section.
This is the second time NMFS has promulgated incidental take
regulations pursuant to the MMPA relating to similar military readiness
activities in the EGTTR. 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).
Most operations during the current effective period are a
continuation of the same operations conducted by the same military
units during the previous mission period. There will, however, be an
increase in the annual quantities of all general categories of
munitions (bombs, missiles, and gun ammunition) under the USAF's
planned activities, except for live gun ammunition, which will be used
less over the next mission period. The highest net explosive weight
(NEW) of the munitions under the USAF's activities will be 945 pounds
(lb) (430 kilograms (kg)), which was also the highest NEW for the
previous mission period. Live missions planned for the 2023-2030 period
will be conducted in the existing Live Impact Area (LIA) within the
EGTTR. Certain missions may also be conducted in the East LIA, which is
a new, separate area within the EGTTR where live and inert munitions
will 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 cover
testing

[[Page 24060]]

and training activities in the EGTTR and will be effective for seven
years, beginning from the date of issuance.

Description of the Specified Activity

A detailed description of the specified activity was provided in
our Federal Register notice of proposed rulemaking (88 FR 8146;
February 7, 2023); please see that notice of proposed rulemaking or the
USAF's application for more information. The USAF requested
authorization to take marine mammals incidental to conducting training
and testing activities in the EGTTR. The USAF has determined that
acoustic and explosives stressors are most likely to result in impacts
on marine mammals that could rise to the level of harassment, qualify
as take under the MMPA, and NMFS concurs with this determination. Eglin
plans 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 rulemaking/LOA
application (<a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-air-force-eglin-gulf-testing-and-training">https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-air-force-eglin-gulf-testing-and-training</a>) and are
summarized here.

Dates and Duration

The specified activities will occur at any time during the 7-year
period of validity of the regulations. The planned 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 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 planned 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. 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 planned activities provide for the creation of a new,
separate area within the EGTTR that will be used for live missions in
addition to the existing LIA. This area, herein referred to as the East
LIA, is located approximately 40 nmi 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 East LIA is circular-shaped and has a radius of approximately 10
nmi (18.5 km) and a total area of approximately 314 nmi\2\. Water
depths range from approximately 35 to 95 m. The East LIA will 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 will allow testing of
weapon systems and flight profiles that cannot be conducted within the
constraints of the existing LIA.

Detailed Description of the Specified Activities

This section provides descriptions of each military user group's
planned EGTTR operations, as well as information regarding munitions
planned to be used during the operations. This information includes
munition type, category, net explosive weight (NEW), detonation
scenario, and annual quantity planned 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 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 planned annual expenditures of
munitions are the quantities determined necessary to meet the mission
requirements of the user groups.
Live missions planned for the 2023-2030 period would be conducted
in the existing LIA and the 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 required mitigation and monitoring
measures.
Eglin AFB plans to implement the following actions in the EGTTR
which would be conducted in the existing LIA

[[Page 24061]]

and the East LIA, depending on the mission type and objectives:
(1) 53rd Weapons Evaluation Group missions that involve air-to-
surface tests various types of munitions against small target boats,
and air-to-air missile testing;
(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, and other
aircraft air-to-surface testing; and 780th Test Squadron weapons
testing of air-launched cruise missiles, air-to-air missiles, air-to-
surface missiles, and surface-to-air missiles 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) for 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. Missions planned in the EGTTR for the 2023-2030 period
would involve the use of several types of 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 53
WEG missions in the EGTTR, including missiles, bombs, and gun
ammunition. Table 1 presents information on the munitions planned for
53 WEG air-to-surface missions in the EGTTR during the 2023-2030
period.

Table 1--Planned Munitions for 53 WEG Air-to-Surface Missions in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb)/ Destination scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
Rocket.................................... 9.1 (4.1) Surface......................... 12
Missile................................... 240.26 (108.9) Surface......................... 4
Missile................................... 240.26 (108.9) Surface......................... 3
Missile................................... 240.26 (108.9) Surface......................... 3
Missile................................... 150 (68) Surface......................... 5
Missile................................... 145 (65.7) Surface......................... 5
Missile................................... 150 (68) Surface......................... 5
Missile................................... 145 (65.7) Surface......................... 4
Missile................................... 150 (68) Surface......................... 5
Missile................................... 29.1 (13.2) Surface......................... 4
Missile................................... 29.94 (13.6) Surface......................... 4
Missile................................... 27.41 (12.4) Surface......................... 4
Missile................................... 27.38 (12.4) Surface......................... 4
Missile................................... 20.16 (9.1) Surface......................... 4
Bomb...................................... 108.6 (49.5) HOB............................. 8
Bomb...................................... \a\ 0.34(0.1) HOB/Surface..................... 8
Bomb...................................... \a\ 0.39(0.1) Surface......................... 4
Missile................................... \a\ 0.70 Surface......................... 2
(0.31)
Missile................................... \a\ 0.70 Surface......................... 2
(0.31)
Missile................................... \a\ 0.70(0.31) Surface......................... 2
Missile................................... \a\ 0.70(0.31) Surface......................... 2
Missile................................... 27.47(12.5) Surface......................... 4
Bomb...................................... 6.88 (3.1) Surface......................... 2
Bomb...................................... 6.88 (3.1) Surface......................... 4
Missile................................... 8.14 (3.7) Surface......................... 4
Bomb...................................... 193 (87.5) Surface......................... 4
Bomb...................................... 193 Surface......................... 4
Gun Ammunition............................ 4.7 Surface......................... 100
Inert Munitions:
Missile................................... N/A N/A............................. 4
Missile................................... N/A N/A............................. 4
Missile................................... N/A N/A............................. 4
Missile................................... N/A N/A............................. 4
Bomb...................................... N/A N/A............................. 8
Bomb...................................... N/A N/A............................. 32
Bomb...................................... N/A N/A............................. 16
Bomb...................................... N/A N/A............................. 16
Bomb...................................... N/A N/A............................. 2
Bomb...................................... N/A N/A............................. 16
Bomb...................................... N/A N/A............................. 16
Bomb...................................... N/A N/A............................. 2
Bomb...................................... N/A N/A............................. 2
Bomb...................................... N/A N/A............................. 8
Bomb...................................... N/A N/A............................. 4
Bomb...................................... N/A N/A............................. 4

[[Page 24062]]

Bomb...................................... N/A N/A............................. 10
Bomb...................................... N/A N/A............................. 4
Bomb...................................... N/A N/A............................. 4
Bomb...................................... N/A N/A............................. 2
Bomb...................................... N/A N/A............................. 4
Gun Ammunition............................ 0.09 (0.04) N/A............................. 16,000
Gun Ammunition............................ N/A N/A............................. 16,000
Gun Ammunition............................ N/A N/A............................. 16,000
Decoy System.............................. N/A N/A............................. 6
----------------------------------------------------------------------------------------------------------------
\a\ Warhead replaced by FTS/Tactical Missile (TM). Identified NEW is for the FTS.
EGTTR = Eglin Gulf Test and Training Range.

The 53 WEG also conducts live air-to-air missile testing in the
EGTTR. These 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 missiles at
sub-and full-scale Aerial Targets to evaluate the effectiveness of
missile delivery techniques. These missions involve the use of several
types of fighter aircraft. Table 2 presents information on the
munitions planned to be used during 53 WEG missions in the EGTTR.

Table 2--Planned Munitions for 53 WEG Air-to-Air Missions in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb)/ Detonation scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
Missile................................... 113.05 (51.3) HOB............................. 24
Missile................................... 113.05 (51.3) HOB............................. 10
Missile................................... 113.05 (51.3) HOB............................. 8
Missile................................... 102.65 (46.5) HOB............................. 14
Missile................................... 117.94 (63.5) HOB/Surface..................... 4
Missile................................... 102.65 (46.5) HOB............................. 18
Missile................................... 60.25 (27.3) HOB............................. 7
Missile................................... 67.9 (30.8) HOB/Surface..................... 10
Missile................................... 60.25 (27.3) HOB............................. 24
Missile................................... 60.55 (27.3) HOB............................. 90
Inert Munitions:
Missile................................... N/A N/A............................. 4
Gun Ammunition............................ N/A N/A............................. 80,000
Gun Ammunition............................ N/A N/A............................. 6,000
Flare..................................... N/A N/A............................. 1,800
Chaff..................................... N/A N/A............................. 6,000
Chaff..................................... N/A N/A............................. 1,500
----------------------------------------------------------------------------------------------------------------
EGTTR = Eglin Gulf Test and Training Range; HOB = height of burst; lb = pound(s); mm = millimeter(s); N/A = not
applicable.

Air Force Special Operations Command Training
The Air Force Special Operations Command (AFSOC) plans 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 planned for AC-130
gunnery training by AFSOC.

[[Page 24063]]

Table 3--Planned Rounds for AC-130 Gunnery Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
Number of Rounds per Annual
Net explosive weight (lb)/(kg) Detonation scenario missions mission quantity
----------------------------------------------------------------------------------------------------------------
Daytime Missions:
4.7 (2.1)......................... Surface................. 25 30 750
0.1 (0.04)........................ 500 12,500
Nighttime Missions:
0.35 (0.2)........................ Surface................. 45 30 1,350
0.1 (0.04)........................ 500 22,500
-----------------------------------------------
Total......................... 70 37,100
----------------------------------------------------------------------------------------------------------------
EGTTR = Eglin Gulf Test and Training Range.

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
planned for CV-22 training missions.

Table 4--Planned Rounds for CV-22 Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
Number of Rounds per Annual
Net explosive weight (lb) Detonation scenario missions mission quantity
----------------------------------------------------------------------------------------------------------------
Daytime Missions:
N/A............................... Surface................. 25 600 15,000
Nighttime Missions:
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 live and inert bombs and missiles as shown in Table 5. These
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--Planned Munitions for AFSOC Bomb and Missile Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb) Detonation scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
Missile................................... 4.58 (2.1) HOB............................. 100
Missile................................... 20.0 (9.07) HOB............................. 70
Rocket.................................... 2.3 (1.0) Surface......................... 400
Bomb...................................... 198.0 (89.8)/ Surface......................... 30
298.0 (135.1)
Bomb...................................... 151.0 (98.4) Surface......................... 30
Bomb...................................... 37.0 (16.7) HOB............................. 30
Bomb...................................... 36.0 (16.3) HOB............................. 40
Inert Munitions:
Gun Ammunition............................ N/A N/A............................. 30,000
Bomb...................................... N/A N/A............................. 30
Bomb...................................... N/A N/A............................. 30
Bomb...................................... N/A N/A............................. 30
Bomb...................................... N/A N/A............................. 50
----------------------------------------------------------------------------------------------------------------
AFSOC = Air Force Special Operations Command; height of burst; lb = pound(s); Mk = Mark; N/A = not applicable.

96th Operations Group
Three units under the 96th Operations Group (96 OG) plan 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 plans to continue conducting AC-130 systems and
munitions testing in the EGTTR. AC-130 gunnery testing is generally
similar to activities previously described for AFSOC AC-130 gunnery
training.

[[Page 24064]]

Table 6 presents information on the munitions planned for AC-130
testing in the EGTTR during the 2023-2030 mission period.

Table 6--Planned Rounds for AC-130 Gunnery Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb)/ Detonation scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
Missile....................................... 4.58 (2.1) Surface......................... 10
Missile................................... 20.0 (9.1) Surface......................... 10
Bomb...................................... 37.0 (16.8) Surface......................... 6
Bomb...................................... 37.0 (16.8) Surface......................... 10
Gun Ammunition............................ 4.7 (2.1) Surface......................... 60
Gun Ammunition............................ 0.35 (0.2) Surface......................... 60
Gun Ammunition............................ 0.1 (0.1) Surface......................... 99
----------------------------------------------------------------------------------------------------------------
EGTTR = Eglin Gulf Test and Training Range.

The 96 OSS plans to conduct air-to-surface testing in the EGTTR
using assorted live missiles and live and inert precision-guided bombs
to support testing requirements for multiple programs. The planned
munitions would include captive carry and munitions employment tests.
During munition employment tests, the planned munitions would be
launched from aircraft at various types of static and moving targets on
the water surface. Table 7 presents information on the munitions
planned by the 96 OSS for testing in the EGTTR.

Table 7--Planned Munitions for 95 OSS Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb)/ Detonation scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
Missile................................... 20.0 (9.1) Surface......................... 36
Missile................................... 7.9 (3.6) HOB............................. 1
Bomb...................................... 37.0 (16.8) Surface......................... 2
Inert Munitions:
Bomb...................................... N/A N/A............................. 2
Bomb...................................... N/A N/A............................. 10
Bomb...................................... N/A N/A............................. 1
----------------------------------------------------------------------------------------------------------------
EGTTR = Eglin Gulf Test and Training Range.

The 780 TS, the Air Force Life Cycle Management Center, and the
U.S. Navy jointly conduct some test missions in the EGTTR. These
missions use precision-guided bombs. Some munitions 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. Other
munitions 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 munition launches, two munitions would be launched from
the same aircraft at approximately the same time to strike the same
target. These simultaneously launched munitions 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 780 TS 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 780 TS tests in the EGTTR during the 2023-2030 mission period
may include operational testing of a third bomb munition. These tests
may involve live and inert testing of the munition against target
boats.
Table 8 presents information on the munitions planned for these 780
TS missions in the EGTTR during the 2023-2030 period.

Table 8--Planned Munitions for Precision Strike Weapon Missions
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb)/ Detonation scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
Missile................................... 240.26 (108.9) Surface......................... 2
Bomb...................................... 37.0 (16.8) HOB/Surface..................... 2
Bomb \a\.................................. 74.0 (33.35) HOB/Surface..................... 2
Bomb...................................... 22.84 (10.4) HOB/Surface..................... 2
Inert Munitions:
Missile................................... N/A N/A............................. 4
Bomb...................................... N/A N/A............................. 4

[[Page 24065]]

Bomb...................................... N/A N/A............................. 4
Bomb...................................... N/A N/A............................. 1
----------------------------------------------------------------------------------------------------------------
\a\ NEW is doubled for simultaneous launch.
EGTTR = Eglin Gulf Test and Training Range; lb = pound(s); N/A = not applicable.

The 780 TS, along with the Air Force Life Cycle Management Center
and U.S. Navy, plans to jointly conduct air-to-air missile testing in
the EGTTR. These missions would involve the use of missiles; all
missiles used in these tests would be inert. Table 9 presents
information on the munitions planned for air-to-air missile testing
missions in the EGTTR during the 2023-2030 mission period.

Table 9--Planned Munitions for 780 TS Air-to-Air Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Annual
Category weight (lb) Detonation scenario quantity
----------------------------------------------------------------------------------------------------------------
Missile................................... N/A N/A............................. 6
Missile................................... N/A N/A............................. 10
Missile................................... N/A N/A............................. 15
----------------------------------------------------------------------------------------------------------------
EGTTR = Eglin Gulf Test and Training Range; lb = pound(s); N/A = not applicable.

The 780 TS plans to test the ability of other missiles to track and
impact moving target boats in the EGTTR as shown in Table 10. 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).

Table 10--Planned Munitions for 780 TS Other Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb)/ Detonation scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Missile................................... 35.95 (16.3) HOB............................. 6
Missile................................... 27.47 (11.1) HOB............................. 8
----------------------------------------------------------------------------------------------------------------
EGTTR = Eglin Gulf Test and Training Range; HOB = height of burst; lb = pound(s).

The 780 TS plans to test an air-to-surface tactical missile system
against static and moving target boats in the EGTTR. These missiles
shown in Table 11 would target 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--Planned Munitions for 780 TS Other Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb)/ Detonation scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Missile................................... 34.08 (14.5) Surface......................... 3
----------------------------------------------------------------------------------------------------------------

The 780 TS plans to conduct surface-to-air testing of missiles in
the EGTTR. These missiles are expected to be fired from the A-15 launch
site on Santa Rosa Island in the EGTTR. Detailed operational data for
this testing are not yet available. Standard inventory missiles would
be used and up to eight tests of one type and two tests of another type
per year are planned as shown in Table 12.

Table 12--Planned Munitions for 780 TS Surface-to-Air Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb)/ Detonation scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Missile....................................... \a\ 145.0 N/A (drone target).............. 8
(65.7)
Missile....................................... \a\ 145.0 N/A (drone target).............. 2
(65.7)
----------------------------------------------------------------------------------------------------------------
\a\ Assumed for impact analysis.

[[Page 24066]]

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 hypersonic weapon programs which are presented
in Table 13.
780 TS plans to conduct testing of one type of hypersonic missile,
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 these
tests are to be determined; the flight corridor is expected to be 300
to 400 nmi (555 to 740 km) in total length. Live types of missiles
would be fired from the southern portion of the EGTTR into either the
existing LIA or planned East LIA. Up to two live of these live missiles
per year are planned to be tested in the EGTTR during the 2023-2030
mission period.
The 780 TS in coordination with the U.S. Army plans to conduct
testing of another type of hypersonic missile in the EGTTR. Some
testing of these missiles is expected to involve surface launches from
the A-15 launch site on Santa Rosa Island. The dimensions and
orientation of the test flight corridor within the EGTTR for these
tests are to be determined; the flight corridor is expected to be 162
to 270 nmi (300 to 500 km) in total length. For tests that involve a
live warhead on these missiles, they 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 planned with these
live missiles would be required to be in the existing LIA or East LIA.
Like inert of the previously mentioned missile type, inerts of this
type 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--Planned Munitions for 780 TS Hypersonic Weapon Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Category weight (lb)/ Detonation scenario Annual
(kg) quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
Hypersonic Weapon......................... \a\ 350 Surface......................... 2
(158.7)
Hypersonic Weapon......................... \a\ 46 (158.7) HOB............................. 2
Inert Munitions:
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,
plans to conduct sink at-sea live-fire training exercises (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--Planned 780 TS SINKEX Exercises in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Type Category weight (lb) Detonation 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--Planned Munitions for Other 780 Test Squadron Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Annual
Category weight (lb)/(kg) Detonation scenario Target type quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
Bomb......................... 945 (428.5)........ Subsurface......... TBD................ 4 to 8
Bomb......................... 945 (428.5) or less HOB................ TBD................ 2
Bomb......................... 0.4 (0.2).......... HOB/Surface........ Small Boat......... 4
Bomb......................... 0.4 (0.2).......... HOB/Surface........ Small Boat......... 4
Inert Munitions:
Missile...................... N/A................ N/A................ TBD................ 7
Booster...................... N/A................ N/A................ TBD................ 1
Bomb......................... N/A................ N/A................ Water Surface and 3
Barge.
Torpedo...................... N/A................ N/A................ Water Surface...... 2
----------------------------------------------------------------------------------------------------------------
EGTTR = Eglin Gulf Test and Training Range; HOB = height of burst; lb = pound; (N/A = not applicable; TBD = to
be determined.

[[Page 24067]]

The 96 OG plans to continue expanding 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 2,000 lb (907 kg) General Purpose (GP)
inert bombs (Table 16).

Table 16--Planned Munitions for Other 96 OG Inert Bomb Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation
Category weight (lb) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Bomb \a\..................................................... N/A N/A 9
----------------------------------------------------------------------------------------------------------------
\a\ Assumed for impact analysis.
EGTTR = Eglin Gulf Test and Training Range; N/A = not applicable.

Naval School Explosive Ordnance Disposal (NAVSCOLEOD)
NAVSCOLEOD plans 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 planned 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 plans 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--Planned Munitions for NAVSCOLEOD Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Type Category weight (lb)/ Detonation scenario Annual
(kg) 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 planned 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 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 gasses 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,

[[Page 24068]]

a large portion of the energy and gasses 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 of the notice of proposed rulemaking published in the
Federal Register (88 FR 8146; February 7, 2023).

Comments and Responses

We published the proposed rule in the Federal Register on February
7, 2023 (88 FR 8146), with a 30-day comment period. With that proposed
rule, we requested public input on our analyses, our preliminary
findings, and the proposed regulations, and requested that interested
persons submit relevant information and comments. During the 30-day
comment period, we received 10 comment submissions: one from the Marine
Mammal Commission (Commission) and nine from private citizens. NMFS has
reviewed and considered all public comments received on the proposed
rule and issuance of the LOA. The private citizens' comments generally
expressed disapproval of the action due to perceived potential impact
to the Endangered Species Act (ESA)-listed Rice's whale. Our responses
to all comments that are pertinent to this action are described below.
Comment 1: The Commission wrote that the proposed rule implied that
behavioral takes were not estimated for exercises that included only
one detonation per day. NMFS had noted that the potential for
behavioral response from a single detonation was quantitatively
accounted for by using the temporary threshold shift (TTS) threshold.
Since the Commission believes that behavioral takes should be
authorized for activities involving single detonations, it recommended
that NMFS authorize the Level B harassment behavior takes of marine
mammals, in addition to TTS takes, for mission-day categories J and K
in the final rule or any LOA issued thereunder and ensure that the
preamble to the final rule is clear regarding the fact that behavior
takes were authorized for single-detonation missions.
Response: NMFS inadvertently conveyed in the proposed rule that the
potential for behavioral response for single detonations was accounted
for within the TTS thresholds/takes (5 dB sound exposure level (SEL)
less than the TTS threshold), which is how NMFS typically recommends
considering behavioral harassment from single detonations. However, the
USAF computed behavioral threshold distances and takes for Missions J
and K (both single detonation) using the underwater acoustic model.
These model runs were done specifically to estimate behavioral effects,
just like other model runs were done to estimate SEL-based TTS and PTS.
Behavioral takes were actually estimated based on the species density
within the area exposed to sound levels from 170 dB SEL to 165 dB SEL,
where 170 dB SEL represents the TTS threshold. This language has been
revised and clarified in the preamble to this final rule. As a general
matter, NMFS continues to find that take by behavioral harassment from
single explosive detonations is unlikely to result from exposures below
the TTS threshold; however, at Eglin Air Force Base's request, we have
authorized these takes to provide coverage in the unlikely event they
should occur.
Comment 2: The Commission notes that to minimize impacts on Rice's
whales, NMFS has prohibited the use of live-fire munitions between the
100- and 400-m isobaths in the existing and new live impact areas
(LIAs) and seaward of the setbacks from the 100-m isobath. The
Commission recommended that NMFS prohibit use of live-fire munitions in
the existing and new LIAs both within the core distribution area (CDA)
and seaward of the setbacks from shallowest depths of the CDA.
Response: Within the LIAs, the CDA boundaries are comprised of
straight lines that generally track along the 100-meter isobath
boundary. The isobath is not a straight line but meanders back and
forth across the CDA boundary. In some areas, the CDA boundary
traverses areas of less depth than the 100-m isobath. Rice's whale
densities are extremely low at the 100-meter isobath boundary and would
be statistically meaningless in shallower waters (also no Rice's whale
or other baleanopterid has been sighted by NMFS' aerial surveys in
waters less than 100-m depth in this area, despite extensive coverage
out to the 200-m isobath). The setbacks from the 100-meter isobath
range from 7.323 km (mission-day A) to 0.368 km (mission-day R)
landward. In some portions of both LIAs, the shallowest boundary of the
CDA covers an area that is greater than the given setback distance
landward of the 100-meter isobath. Therefore, using the CDA boundary
would result in additional loss of LIA area for USAF, based on the CDA
boundary itself, which is landward of some of the current setbacks and
based on any new setbacks from the CDA boundary, most of which would be
greater than the current setbacks. Currently, there are no other
suitable locations to conduct live missions in the EGTTR outside the
existing LIA and proposed East LIA. USAF has given up significant
amounts of area within each LIA to reduce potential Level B harassment
to the Rice's whale to the lowest levels practicable. These setbacks
impact all USAF EGTTR missions. Any additional loss of LIA would not be
practicable as it would have a negative disproportionate impact on the
ability of the USAF to conduct missions and on national security
preparedness. Further, as indicated, such an additional setback would
provide little, if any, additional reduction of impacts to Rice's
whales and, accordingly, NMFS has not included this recommendation.
Comment 3: The Commission does not believe that the USAF would be
able to visually monitor effectively for marine mammals entering the
mortality and injury zones, particularly during the time between when
the smaller mission area has been cleared during pre-mission surveys
with vessels exiting beyond the larger human safety zone (up to 13 nmi/
24 km) and the time of detonation(s) which would be a minimum of 30
minutes. The Commission also notes that the USAF video cameras
available to assist with visual monitoring are not always used or
operational when intended to be used. The Commission also noted that
due to high altitudes of aircraft used during aerial surveillance,
effective monitoring is not possible.
Response: NMFS disagrees with the Commission's assertions for
several reasons. The 24 km (12.9 nmi) distance is for the largest, and
less frequent, net-

[[Page 24069]]

explosive weight (NEW) mission days when the detonation would be 945
lbs. This would occur on a maximum of 10 days per year. The Commission
fails to note that the number of vessels employed would be
proportionate to the size of the NEW used on a given mission. Up to 25
vessels would be used on days when the largest NEWs are planned.
Further, the vessels will continue to monitor for marine mammals in or
approaching the smaller mitigation zone both as they move outward
towards the human safety zone, and from the edge of the human safety
zone--if the mission area/mitigation zone is clear when they move out
to the human safety zone, it is unlikely that a marine mammal would
pass by the monitors to the inner mitigation zone in the next 30
minutes without being seen.
NMFS notes that video cameras are planned/required for use in all
regular situations, and might not be used in situations of unplanned
circumstances, such as in cases of equipment malfunction. In such
situations, the test engineer and other staff can make a decision to
delay, cancel, or postpone a mission due to asset status (i.e., if
video cameras are also unavailable or malfunctioning).
Regarding the effectiveness of aerial monitoring, NMFS notes that
the electro-optical sensors employed by the USAF were specifically
designed to detect targets on the electromagnetic spectrum under such
areal and altitudinal parameters. NMFS is confident in the USAF's
ability to effectively monitor for marine mammals from aircraft and
marine vessels.
Comment 4: The Commission has previously recommended that the
USAF's mitigation measures be supplemented with passive acoustic
monitoring (PAM). As part of the previous 2018 rulemaking and issued
LOA, NMFS required the USAF to: (1) conduct a PAM study as an initial
step toward understanding acoustic impacts of underwater detonations,
if funding was approved, and (2) conduct a follow-up PAM study to
investigate marine mammal vocalizations before, during and after live
missions in the EGTTR. The Commission recommended as part of this final
rule that NMFS require the USAF to prioritize (1) completing both
aspects of its PAM study and (2) further investigate ways to supplement
its mitigation measures with the use of real-time PAM devices (i.e.,
sonobuoys or hydrophones) in any final rule issued, similar to the
previous final rule.
Response: The USAF conducted a single PAM study (Leidos 2020) on
underwater detonations which was the first of the two-part condition of
the 2018-2023 LOA. The study determined that inert underwater
detonations were generally louder than expected. As a result of these
findings, the USAF included analyses of impacts of inert munitions in
the LOA application and NMFS is requiring appropriate mitigation
measures for inert munitions.
As of this writing, funding has been requested from near-term
funding sources but has not yet been approved by the USAF for the
second part of the study, which was to follow up on the results of the
initial PAM study. NMFS and the USAF have reviewed the findings from
the initial study and will discuss specific next steps. Furthermore,
NMFS has included language in this final rule and the LOA requiring the
USAF to prioritize studies to (1) follow up on the results of the
initial PAM study by investigating marine mammal vocalizations before,
during, and after live missions in the EGTTR, pending the availability
of funding; and (2) investigate ways to supplement its mitigation
measures with the use of real-time PAM devices, pending the
availability of funding.
The Commission recommended that NMFS and the USAF investigate the
possible use of sonobuoys for the second part of the study. NMFS and
the USAF appreciate the Commission's recommendations regarding possible
use of various types of sonobuoys.
Comment 5: The Commission recommended that NMFS require the USAF to
implement mitigation measures for SINKEX activities that are similar to
those required by NMFS for incidental take regulations for the U.S.
Navy.
Response: Below, NMFS addresses each of the specific mitigation
measures recommended by the Commission (i.e., mitigation measures for
SINKEX activities that are similar to those required by NMFS for U.S.
Navy incidental take regulations.
(1) The Commission recommended that the USAF establish two
platforms (aerial and vessel) for conducting visual monitoring of a
4.6-km mitigation zone from 90 minutes before the first firing.
NMFS will require all range clearing vessels to be on site 90
minutes before the mission to clear the prescribed human safety zone
and survey the mitigation zone for the given mission-day category. Up
to 25 vessels will be used depending upon the size of the NEW. Not all
of these vessels will contain PSOs, but these will also be looking for
marine mammals in addition to range-clearing exercises. PSOs will be
stationed on all vessels that are required to monitor the mitigation
zones for the given mission-day category for a minimum of 30 minutes or
until the entirety of the mitigation zone has been surveyed, whichever
takes longer. Furthermore, 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.
While the aerial platforms may not always be onsite 90 minutes
before the mission, the measures required in these regulations provide
similar equivalent protection, as the entirety of the mitigation zone
will have been monitored by PSOs on vessels and aircraft a short time
before the mission commences.
(2) The Commission recommended that the USAF should conduct both
visual monitoring from a vessel and passive acoustic monitoring of the
mitigation zone during the exercise.
Real-time visual monitoring from a vessel would pose a safety
threat to both the PSO as well as crew of the vessel. All vessels must
have exited the human safety zone prior to the commencement of SINKEX
activities. The large size of the human safety zone means that extended
distance from a vessel to the SINKEX target area would not allow for
effective monitoring from a vessel. However, video-based monitoring
will be employed during SINKEX missions, which provides real-time
observation data for the mitigation zone.
NMFS has engaged in multiple discussions with the USAF about the
implementation of PAM. However, human safety concerns and the inability
to make mission go/no-go decisions in a timely manner are the most
immediate obstacles for the USAF implementing PAM as part of the suite
of mitigation measures during live weapon missions in the EGTTR. For
safety purposes during live air-to-surface missions in the EGTTR and
during SINKEX exercises portions of the Gulf of Mexico are closed off
to human activity. The human safety zone corresponds to the weapon
safety footprint. The size of the closure area varies depending on the
weapons being dropped, the type of aircraft being used, and the
specific release parameters (direction, altitude, airspeed, etc.)
requested by the mission group, but it always encompasses the area
occupied by the instrumentation barge (GRATV). Typically, this
footprint is where personnel are restricted to ranges between a 9-
nautical mile (nmi) radius up to a 12-nmi radius around the GRATV from
the target and the GRATV that is usually within hundreds of meters of
the target. As part of PAM, biologists generally deploy an array of
hydrophones, listen for vocalizations

[[Page 24070]]

from a nearby boat, and use software to triangulate an animal's general
location. The ability to execute this requires multiple hydrophones
lined up in a carefully determined array or fence configuration with a
trained biologist in close proximity to the hydrophones. Alternatively,
the biologist could be stationed in a remote location but would require
a direct line-of-sight for radio links to transmit the data from the
hydrophones. The maximum distance that a remote link could be
established is estimated to be about 5 nmi. This would fall inside the
human safety zone. Therefore, real-time monitoring for marine mammal
vocalizations during a SINKEX mission is not considered feasible for
human safety concerns.
The USAF is supportive of PAM and has conducted a NMFS-approved PAM
study in 2020 to increase our understanding of acoustic impacts
associated with underwater detonations. Given the need for additional
research as recommended by the Commission, additional studies have been
established as conditions of these regulations and LOA. Development,
testing and full implementation of a real-time PAM system is not likely
feasible during the effective period of the new LOA due to human safety
concerns and the need for additional investigations of efficacious
protocols. Considering all of this, the use of PAM as a real-time
mitigation measure is not practicable at this time.
(3) The Commission recommended that the USAF observe marine mammals
in the vicinity of where detonations occurred for 2 hr after sinking
the vessel or until sunset (whichever comes first).
The post-mission survey area will be the area covered in 30 minutes
of observation by both aerial crews and vessels in a direction down-
current from the impact site or the actual pre-mission survey area,
whichever is reached first. PSOs must survey the mission site for any
dead or injured marine mammals. Additionally, post-mission cleanup
operations will recover as much target-related debris as possible from
the water surface by hand and by using dip nets. The USAF reports that
typical post-cleanup operations involve the use of up to 10 vessels for
up to 2 to 3 hours depending on the size of the NEW, and personnel on
these vessels will be instructed to report any dead or injured marine
mammals to the Lead Biologist. NMFS is not requiring a minimum time
limit or specifying the number of vessels that must be employed post
mission since it is difficult, if not impossible, to predict how much
debris will occur at or near a given SINKEX mission location.
Furthermore, it is inefficient and costly to require multiple vessels
primarily engaged in cleanup activities to continue monitoring for
extended periods after cleanup is complete. For single-detonation
SINKEX actions, the USAF has committed to survey the entirety of the
mission area or survey for 30 minutes, whichever comes first.
(4) The Commission recommended that any additional platforms
supporting the primary mission activity (e.g., providing range
clearance) must assist in visual observation of the area where
detonations occurred.
As noted above, up to 10 USAF support vessels primarily focused on
collecting debris will spend several hours in the mission area
collecting debris from damaged targets. All vessels will be instructed
to report any dead or injured marine mammals to the Lead Biologist.
In summary, with the exception of PAM, which NMFS concurs with the
USAF is not practicable at this time, the USAF's required mitigation
and monitoring measures are either similar to those employed by the
Navy or provide comparable protection. Further, as noted, a requirement
to investigate ways to supplement the USAF's mitigation measures with
the use of real-time PAM devices has been included in these
regulations. Monitoring reports under the LOA effective from 2018
through 2021 have not recorded take of any marine mammals. Only
bottlenose dolphins have been observed and there have not been
sightings of whales of any species. Based on the information above,
NMFS has determined that the mandated mitigation and monitoring
measures required for SINKEX activities in the EGTTR effect the least
practicable adverse impact on the affected species and their habitat.
Therefore, NMFS is not adopting the Commission's recommendation that
the USAF measures be changed to mirror the Navy's protocols.
Comment 6: Several commenters wrote that the USAF should not be
permitted to take marine mammals in the EGTTR since they are protected
by the Marine Mammal Protection act and the Endangered Species Act;
therefore, all activities that may harm the species are required to be
banned.
Response: Both the MMPA and the ESA allow for the take of marine
mammals or ESA-listed species, respectively, provided certain findings
are made. Further, the MMPA states that NMFS ``shall issue'' incidental
take authorizations provided the necessary findings are made. As
described in this final rule, NMFS' analysis supports our determination
that the authorized takes will have a negligible impact on the affected
species or stocks. Further, we have included required mitigation
measures that ensure that the testing and training activities in the
EGTTR will have the least practicable adverse impact on affected marine
mammal species or stocks.
Comment 7: One commenter wrote that the activities proposed by the
USAF in the EGTTR would exacerbate threats to the Rice's whale, leading
the species to its eventual demise. Therefore, NMFS is unable to make a
negligible impact determination regarding the species. As such, the
requested incidental take should not be authorized. A separate
commenter wrote that changes in marine mammal behavior have been found
to directly impact health, including immunological changes in marine
mammals, making individuals more susceptible to infection and making
populations more susceptible to disease exposure. The commenter stated
that this level of impact could have serious repercussions for the
species as a whole and cannot be considered negligible.
Response: There is no evidence to support the statement that the
USAF's planned activities in the EGTTR would lead to the extinction of
the species. As indicated in our analysis and by the authorization of a
low number of takes by Level B harassment (no more than 6 in any year),
NMFS acknowledges that some level of impact, in the form of behavioral
disturbance, is likely to occur in the Rice's whale. However, as
required to allow for incidental take, we further determined that such
impacts resulting from the specified activity are not reasonably
expected to, or not reasonably likely to, adversely affect the species
or stock through effects on annual rates of recruitment or survival
(i.e., population-level effects). As discussed in the proposed rule and
this final rule, NMFS made a negligible impact determination. Since
NMFS did arrive at a negligible impact determination and satisfied the
MMPA requirements, there are no legal grounds for prohibiting
authorized take.
Comment 8: One commenter wrote that testing explosives in the EGTTR
could affect marine mammals even if they are not present since sources
of food could be disturbed for the mammals, changing their hunting
patterns, and disrupting the ecosystem.
Response: The Potential Effects of Specified Activities on Marine
Mammals and Their Habitat section of the proposed rule (88 FR 8146,
February 7, 2023) described the potential impacts of EGTTR activities
on marine mammal habitat and prey sources. NMFS

[[Page 24071]]

acknowledges that explosive detonations can impact both fish and
invertebrate prey sources in manners ranging from behavioral
disturbance to mortality for animals that are very close to the source.
However, as described in the analysis, these impacts are expected to be
short term and localized, and would be inconsequential to the fish and
invertebrate populations, and to the marine mammals that use them as
prey.
Comment 9: One commenter mistakenly wrote that the USAF anticipated
take resulting from Level A and Level B harassment of Rice's whales
with authorized Level A harassment of 2 Rice's whale, permanent
threshold shifts (PTS) of 4 individuals, temporary threshold shifts
(TTS) of 14 individuals, and behavior disturbance of 28 individuals
over the 7-year analysis period (NMFS 2023). The commenter further
suggested that since the species abundance is 51 individuals, the
anticipated take numbers are proportionally significant, particularly
when it comes to behavioral impacts, which are anticipated to affect
the majority of the population (56 percent) over a seven-year period.
Response: The commenter is incorrect regarding the number of PTS
and TTS takes. NMFS has authorized 6 takes by Level B harassment per
year (2 by TTS and 4 behavioral harassment). NMFS does not expect and
has not authorized take of Rice's whale by Level A harassment.
Further, if one assumes that each of the 6 annual exposures is
incurred by a different whale, these authorized takes affect 11.8
percent (6/51) of the population during any given year. Importantly,
each of those instances of take represents exposure within 1 day of the
year. This represents low magnitude, short duration impacts to a
relatively small portion of the total population.
Comment 10: One commenter wrote that the Rice's whale is highly
sensitive to any anthropogenic forces and, therefore, authorization of
the proposed activities would result in significant impacts and violate
section 101 of the MMPA. They wrote that it was time for NMFS to
fulfill their duty to conserve and protect this important marine
resource by denying the USAF's request to take Rice's whales. Another
commenter asked if it is necessary to test these weapons in the water.
They stated that this represents a risk to ocean life and that there
should be other options for locations to test military weapons. Another
commenter asked why these military testing activities must take place
where species stocks are struggling.
Response: NMFS acknowledges the comments and refers back to the
response to comment 6 above. Assuming that the requirements of the MMPA
are met, e.g., findings of negligible impact and least practicable
adverse impact, NMFS does not have discretion as to whether it may
issue incidental take regulations (ITRs) and LOAs under those ITRs and
shall prescribe mitigation measures that ensure the least practicable
adverse impact on marine mammals and their habitat as defined in the
military readiness provisions of the MMPA.
Comment 11: A commenter noted that the USAF entirely ignores
potential impacts resulting from increased vessel traffic in Rice's
whale habitat. The LOA Request details that EGTTR missions require up
to 25 mission-support boats to establish a ``safety zone'' prior to and
throughout the missions; as well as vessels for post-mission surveys
and debris cleanup. For an endangered marine mammal whose primary
habitat is already overlapping with high-traffic channels, the
commenter wrote that recognition of the potential for vessel strikes is
warranted.
Response: NMFS has considered the number of vessels involved in the
activity and the potential for vessel strike. The number of USAF
vessels required for any given mission day category will vary depending
on the mission-day category and the size of the NEW. The use of 25
vessels would occur infrequently when explosives with the largest NEWs
would be deployed, and their entire purpose would be to detect and
minimize impacts to marine mammals. Furthermore, all USAF vessels must
adhere to required vessel strike avoidance measures that are expected
to avoid strikes of marine mammals. Specifically, measures require
vessels to stay 500 m away from any sighted 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. Additionally, vessels must avoid transit in the Rice's
whale 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. The LIAs themselves overlay only a
portion of the Rice's whale CDA.
No Air Force vessels have ever struck a whale in the EGTTR. Given
the required vessel strike avoidance measures, the infrequency of
vessel strikes more broadly, and the comparatively low numbers of
vessels used in EGTTR activities, the potential for strike by a USAF
vessel of any marine mammal is considered so low as to be discountable,
and this is especially true for the Rice's whale, given their low
density. NMFS does not anticipate, and has not authorized, vessel
strike of Rice's whales or any other marine mammal.
Comment 12: A commenter stated that the proposed regulation fails
to provide for long-term environmental monitoring plans, and cleanup
initiatives, in response to the contamination associated with the
disposal of ordnance and target vessels in the sea. The commenter urged
NMFS to expand the proposed rule to include such items. They referred
to the Military Munitions Response Program, which addresses munitions-
related concerns, such as environmental and health hazards from
releases of unexploded ordnance (UXO) and discarded military munitions
(DDM), and prioritizes sites for cleanup based on risks to the
environment.
Response: There is no evidence that USAF activities in the EGTTR
result in contamination from UXOs, target vessels or any other mission-
related activities. USAF post-mission cleanup procedures minimize the
amount of mission-related debris that remains on the water surface and
in the water column. Post-mission cleanup crews recover as much target-
related debris as possible from the water surface by hand and by using
dip nets; typical post-cleanup operations involve the use of several
boats for up to 2 to 3 hours. Target-related debris that is not
recovered by cleanup crews is dispersed by ocean currents, and much of
it is expected to eventually settle on the seafloor. Based on the
amount of target-related debris that would be deposited into the marine
environment, post-mission cleanup of the debris, and dispersion of the
unrecoverable debris by ocean currents, we conclude that any associated
impacts on marine mammal habitat would be minimal.
After being deposited on the seafloor, debris items may become
partially or entirely buried in sediments over time, depending on the
item's size, shape, and density, and environmental factors such as
sediment characteristics, water depth, and the occurrence of strong
storms that may move sediments. Munitions that become buried deep in
sediments may experience less corrosion because of low oxygen levels
and may remain intact for longer periods of time. Inert munitions and
UXO that settle on the seafloor would displace the habitat provided by
the affected sediments to benthic epifauna and infauna but, like other
sunken artificial structures, would also provide substrate that could
be used as habitat by marine organisms. The

[[Page 24072]]

overall level of disturbance to marine sediments in the EGTTR from
mission-related debris is expected to be minor based on the quantity of
debris that would be deposited on the seafloor and the expected
behavior of the debris in the marine environment over time. Based on
the analysis conducted in the current EGTTR Range Environmental
Assessment (REA) regarding metals, explosives, and other materials
associated with EGTTR operations, USAF activities would have been
unlikely to adversely impact water or sediment quality. The analyses of
these potential impacts are discussed in detail in the current EGTTR
REA (USAF 2022).
The MMPA requires that NMFS include marine mammal monitoring and
reporting measures 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. Monitoring for EGTTR activities is described in the
Monitoring section and requires PSOs to provide description of observed
behaviors (in both the presence and absence of test activities), which
will help us better understand the impacts of EGTTR activities on
marine mammals. There are no MMPA requirements regarding wide-spread
environmental or ecological monitoring beyond what has just been
described. Long-term environmental monitoring and additional cleanup
initiatives are beyond the scope of this action.
Comment 13: One commenter was concerned that explosives compounds
containing carcinogens and toxins can accumulate in coastal
environments and marine organisms, which can cause sub-lethal genetic
and metabolic effects. Furthermore, there is also a risk that chemical
agents will be spread through the food chain.
Response: See the response to comment 12 above.
Comment 14: The commenter wrote that no critical habitat has been
designated for the Rice's whale as is required under the Endangered
Species Act. Therefore, NMFS should make designating critical habitat
for Rice's whales a priority before approving authorizations for the
USAF to participate in military activities that threaten the species'
survival.
Response: Critical habitat is defined as habitat needed to support
recovery of species listed under the Endangered Species Act and NMFS
Fisheries is required to determine whether there are areas that meet
the definition of critical habitat. Currently, NMFS is working on an
ESA rulemaking to propose designation of critical habitat for the
Rice's whale which contains: (1) the biological information used to
determine the specific areas containing the features essential to the
conservation of the species requiring special management, and (2)
consideration of the national security, economic, and other relevant
impacts of designating critical habitat.
The designation of critical habitat for an ESA-listed species, in
this case the Rice's whale, is a separate action and not a prerequisite
to fulfilling our statutory mandate under section 101(a)(5)(A) of the
MMPA.

Changes From the Proposed Rule to the Final Rule

This final rule includes no substantive changes from the proposed
rule. Minor typographical errors were included in several tables in the
proposed rule (i.e., Tables 25, 36, and 37 in the preamble and Table 1
in the regulatory text). The values have been corrected in this final
rule. The exposure analysis and take estimations in the proposed rule
were based on the correct numbers so were not affected by this
typographical error. They remain unchanged as part of this final rule.
The preamble text in the Pre-Mission Surveys section and Sec.
218.64(a)(1)(iii) in the proposed rule stated that ``For all live
missions except gunnery missions, USAF 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.'' This has been revised in the
final rule to read ``. . . for a minimum of 30 minutes or until the
entirety of the mitigation zone has been surveyed, whichever takes
longer.'' NMFS and the USAF believe that this revision ensures that the
entirety of all of the mitigation zones will be monitored. NMFS revised
the language in the preamble pertaining to behavioral harassment
thresholds for single detonations as explained in the response to
Comment 1. Finally, NMFS will require the USAF to conduct two passive
acoustic monitoring (PAM) studies, pending approval of funding. These
studies are described in the response to comment 4 and have been
included in the regulatory text in a new paragraph (f) on acoustic
monitoring within Sec. 218.65, entitled ``Requirements for monitoring
and reporting''.

Description of Marine Mammals in the Area of the Specified Activities

Marine mammal species and their associated stocks that have the
potential to occur in the project are presented in Table 18. The USAF
anticipates the take of individuals of three marine mammal species by
Level B harassment and two of those species by Level A harassment. The
USAF does not request authorization for any serious injuries or
mortalities of marine mammals, and NMFS agrees that serious injury and
mortality is unlikely to occur from the USAF's activities.
The proposed rule included additional information about the species
in this rule, all of which remains valid and applicable but has not
been reprinted in this final rule, including a subsection entitled
Marine Mammal Hearing that described the importance of sound to marine
mammals and characterized the different groups of marine mammals based
on their hearing sensitivity. Therefore, we refer the reader to our
Federal Register notice of proposed rulemaking (88 FR 8146; February 7,
2023) for more information.
Information on the status, distribution, abundance, population
trends, habitat, and ecology of marine mammals in the EGTTR may be
found in Chapter 4 of the USAF's rulemaking/LOA application. NMFS
reviewed this information and found it to be accurate and complete. 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; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports</a>). All values
presented in Table 18 are the most recent available at the time of
publication and are available online at: <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.

[[Page 24073]]

Table 18--Marine Mammals Potentially Present in the Specified Geographical Region
--------------------------------------------------------------------------------------------------------------------------------------------------------
NMFS stock abundance Potential
ESA/MMPA status; (CV, Nmin, most recent biological Annual M/
Common name Scientific name Stock strategic (Y/N) abundance survey) \2\ removal SI \3\
\1\ (PBR)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals):
Rice's whale \4\................ Balaenoptera ricei..... Gulf of Mexico (GOM)... 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 36runcates 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: <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>. CV
is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS' Stock Assessment Reports (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).

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

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 balaenopteridae 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 (<a href="https://www.fisheries.noaa.gov/resource/map/rices-whale-core-distribution-area-map-gis-data">https://www.fisheries.noaa.gov/resource/map/rices-whale-core-distribution-area-map-gis-data</a>) 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.

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.

Potential Effects of Specified Activities on Marine Mammals and Their
Habitat

We provided a detailed discussion of the potential effects of the
specified activities on marine mammals and their habitat in our Federal
Register notice of proposed rulemaking (88 FR 8146; February 7, 2023).
In the Potential Effects of Specified Activities on Marine Mammals and
Their Habitat section of the proposed rule, NMFS provided a description
of the ways marine mammals may be affected by these activities in the
form of sensory impairment (permanent and temporary threshold shift and
acoustic masking), physiological responses (particularly stress
responses), behavioral disturbance, or habitat effects. All of this
information remains valid and applicable. Therefore, we do not reprint
the information here but refer the reader to that document.
Having considered the new information, along with information

[[Page 24074]]

provided in public comments on the proposed rule, we have determined
that there is no new information that substantively affects our
analysis of potential impacts on marine mammals and their habitat that
appeared in the proposed rule, all of which remains applicable and
valid for our assessment of the effects of the USAF's activities during
the seven-year period of this rule.

Estimated Take of Marine Mammals

This section indicates the number of takes that NMFS is proposing
to authorize, which 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 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.
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 authorized, 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 planned 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 planned 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 planned 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 planned 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, 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 planned activity
only includes the use of impulsive (explosives) sources. These
thresholds (Table 19) 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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Additionally, based on the best available science, NMFS uses the
acoustic and pressure thresholds indicated in Table 19 to predict the
onset of TTS, PTS, tissue damage, and mortality for explosives
(impulsive) and other impulsive sound sources.

[[Page 24075]]

Table 19--Onset of TTS, PTS, Tissue Damage, and Mortality Thresholds for Marine Mammals for Explosives and Other Impulsive Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mean onset slight Mean onset
Functional hearing group Species Onset TTS Onset PTS gastrointestinal 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 20 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. However, the USAF computed behavioral threshold distance
and takes for Missions J and K, which are single detonation mission day
categories, by using the underwater acoustic model. These model runs
were done specifically to estimate behavioral effects (just like other
model runs were done to estimate SEL-based TTS and PTS). Behavioral
takes were estimated based on the species density within the area
exposed to sound levels from 170 dB to 165 dB, where 170 dB SEL is the
threshold for TTS. While NMFS considers behavioral harassment at these
lower levels unlikely, we have analyzed and authorized these lower-
level takes as requested by the USAF to provide coverage in the
unlikely event they should occur.

Table 20--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 USAF 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
final 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 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

[[Page 24076]]

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 final 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 planned
live munitions were calculated and included in their total energy
estimations. The impact energies of the inert munitions planned 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, whereas the 1 lb
class represents the largest inert missile. The inert missile has
greater mass but lower impact energy than the bomb; this is because the
bomb'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 21).

Table 21--Impact Energy Classes for Inert Munitions
------------------------------------------------------------------------
Impact energy class (lb TNTeq)/ Approximate weight Approximate
(kg) (lb)/(kg) velocity (Mach)
------------------------------------------------------------------------
2 (0.9)......................... 2,000 (907)....... 1.1.
1 (0.45)........................ 2,250 (1020.3).... 0.9.
0.5 (0.22)...................... 250 to 650 (113.4 Variable.
to 294.8).
0.15 (0.07)..................... 1 to 285 (0.5 to Variable.
129.2).
------------------------------------------------------------------------

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 (Naval Surface Warfare Center (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:
<bullet> SPL: The SPL for a given munition can be explicitly
calculated at a radial distance using the similitude equations.
<bullet> SEL: A commercially available software package, dBSea
(version 2.3), was used to calculate the SEL for each mission day.
<bullet> Positive Impulse: This is the time integral of the initial
positive phase of 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

[[Page 24077]]

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 planned 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 22 presents the source-level SPLs
(at r = 1 meter) calculated for the planned munitions.

Table 22--Calculated Source SPLs for Munitions
----------------------------------------------------------------------------------------------------------------
Peak pressure and decay values
Model NEWi -----------------------------------------------
Modeled explosive (lm)/(kg) Pmax @1 m SPL @1 m dB re
(psi) 1 mPa [Theta] msec
----------------------------------------------------------------------------------------------------------------
Tritonal........................................ 241.36 (109.5) 45961.4858 290.0 0.320
Tritonal........................................ 192.3 (87.2) 42101.8577 289.3 0.302
Comp B.......................................... 98.3 (44.6) 37835.4932 288.3 0.200
PBXN-110........................................ 36.18 (13.4) 24704.864 284.6 0.167
PBXN-110........................................ 20 (9.1) 19617.2833 282.6 0.143
PBXN-110........................................ 13.08 (5.9) 16630.2435 281.2 0.128
PBXN-110........................................ 13.08 (5.9) 16630.2435 281.2 0.128
PBXN-9.......................................... 13.08 (5.9) 17240.2131 281.5 0.124
Comp B.......................................... 3.8 (1.7) 10187.8419 276.9 0.090
Comp B.......................................... 4.72 (2.1) 11118.8384 277.7 0.095
Tritonal........................................ 36.1 (16.4) 22074.1015 283.7 0.198
Tritonal........................................ 36.1 (19.4) 22074.1015 283.7 0.198
PBXN-9.......................................... 0.49 (0.2) 4757.6146 270.3 0.054
PBXN-9.......................................... 0.44 (0.2) 4561.06062 270.0 0.053
Tritonal........................................ 192.3 (87.2) 42101.8577 289.3 0.302
H-6............................................. 100 (45.4) 38017.3815 288.4 0.237
----------------------------------------------------------------------------------------------------------------
[thgr] = shock wave time constant; dB re 1 [mu]Pa = decibel(s) referenced to 1 micropascal; lb = pound(s); lbm =
pound-mass; m = meter(s); mm = millimeter(s); msec = millisecond(s); NEWi = net explosive weight at impact;
Pmax = shock wave peak pressure; psi = pound(s) per square inch; SPL = sound pressure level;

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
largest bombs 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) (Department of the Navy (DoN)
2017) for cetaceans with mid- to high-frequency hearing (dolphins) and
low-frequency hearing (Rice's whale). Behavioral thresholds are set 5
dB below the SEL-based TTS threshold. Table 23 shows calculated SPLs
and SELs for the designated mission-day categories.

Table 23--Calculated Source SPLs and SELs for Mission-Day Categories
----------------------------------------------------------------------------------------------------------------
Source
Mission day Total warhead Modeled NEWi, lbm/ cumulative Source peak
NEW, lbm \a\ (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

[[Page 24078]]

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 planned 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 planned 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 largest bombs.
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 24, a total of 19 mission-day categories (A
through S) were developed as 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 24--Mission-Day Categories for Acoustic Impact Analysis
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Munitions Annual NEWi per mission
User group Mission-day category Category NEWi (lb)/kg Detonation scenario per day Mission days per year quantity day (lb)/(kg)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
53 WEG............................. A Missile............... 241.36 (109.4) Surface............... 4 1.................... 4 2,413.6 (1,095.9)
Missile............... 241.36 (109.4) Surface............... 3 1.................... 3
Missile............... 241.36 (109.4) Surface............... 3 1.................... 3
B Bomb (Mk-82).......... 192.3 (87.2) Surface............... 4 1.................... 4 2,029.9 (920.5)
Bomb (Mk-82).......... 192.3 (87.2) Surface............... 4 1.................... 4
Missile............... 98.3 (44.6) Surface............... 5 1.................... 5
C Missile............... 98.3 (44.6) Surface............... 5 1.................... 5 1,376.2 (624.1)
Missile............... 98.3 (44.6) Surface............... 5 1.................... 5
Missile............... 98.3 (44.6) Surface............... 4 1.................... 4
D Missile............... 98.3 (44.6) Surface............... 5 1.................... 5 836.22 (379.2)
Missile............... 36.18 (16.4) Surface............... 4 1.................... 4
Missile............... 20 (9.1) Surface............... 10 1.................... 10
E Missile............... 13.08 (5.9) Surface............... 4 1.................... 4 997.62 (452.4)
Missile............... 13.08 (5.9) Surface............... 4 1.................... 4
Missile............... 13.08 (5.9) Surface............... 4 1.................... 4
Missile............... 13.08 (5.9) Surface............... 4 1.................... 4
Missile............... 13.08 (5.9) Surface............... 4 1.................... 4
Missile............... 13.08 (5.9) Surface............... 4 1.................... 4
Rocket................ 3.8 (1.7) Surface............... 12 1.................... 12
Missile............... 13.08 (5.9) Surface............... 4 1.................... 4
Gun Ammunition........ 4.72 (2.1) Surface............... 100 1.................... 100
Bomb.................. 36.1 (13.3) Surface............... 2 1.................... 2
Bomb.................. 36.1 (16.3) Surface............... 4 1.................... 4
Missile............... \a\ 0 Surface............... 2 1.................... 2
Missile............... \a\ 0 Surface............... 2 1.................... 2
Missile............... \a\ 0 Surface............... 2 1.................... 2
Missile............... \a\ 0 Surface............... 2 1.................... 2
Bomb.................. 0.49 (0.2) Surface............... 4 1.................... 4

[[Page 24079]]

Bomb.................. 0.44 (0.2) Surface............... 8 1.................... 8
AFSOC.............................. F Bomb (Mk-82).......... 192.3 (87.2) Surface............... 2 15................... 30 584.6 (263.1
Bomb.................. 100 (45.3) Surface............... 2 15................... 30
AFSOC.............................. G Gun Ammunition........ 4.72 (2.1) Surface............... 30 25 (daytime)......... 750 191.6 (86.8)
Gun Ammunition........ 0.1 (0.01) Surface............... 500 12,500
H Gun Ammunition........ 0.37 (0.2) Surface............... 30 45 (nighttime)....... 1,350 61.1 (27.7)
Gun Ammunition........ 0.1 (0.01) Surface............... 500 22,500
I Rocket................ 3.8 (1.7) Surface............... 8 50................... 400 30.4 (13.8)
96 OG.............................. J Bomb (Mk-84).......... 946.8 (429.4) Subsurface............ 1 \b\ 10............... \b\ 10 946.8 (429.4)
K Hypersonic Weapon..... 350 (158.7) Surface............... 1 2.................... 2 350 (158.7)
L Missile............... 241.36 (109.4) Surface............... 2 1.................... 2 627.12 (284.3)
Bomb.................. \c\ 72.2 (32.7) Surface............... 2 1.................... 2
M Bomb.................. 36.1 13.3) Surface............... 4 2.................... 8 324.9 (147.3)
Bomb.................. 36.1 (16.3) Surface............... 5 2.................... 10
N Bomb.................. 36.1 (16.3) Surface............... 2 1.................... 2 238.08 (107.9)
Missile............... 40 (18.1) Surface............... 3 1.................... 3
Bomb.................. 22.94 (10.4) Surface............... 2 1.................... 2
O Missile............... 13.08 (5.9) Surface............... 8 4.................... 36 104.64 (47.5)
P Missile............... 13.08 (5.9) Surface............... 5 2.................... 10 130.8 (59.3)
Missile............... 13.08 (5.9) Surface............... 5 2.................... 10
Q Gun Ammunition........ 4.72 (2.1) Surface............... 20 3.................... 60 94.4 (42.8)
R Bomb.................. 0.49 (0.2) Surface............... 4 1.................... 4 35.82 (16.2)
Bomb.................. 0.44 (0.2) Surface............... 4 1.................... 4
Gun Ammunition........ 0.37 (0.2) Surface............... 60 1.................... 60
Gun Ammunition........ 0.1 (0.01) Surface............... 99 1.................... 99
NAVSCOLEOD......................... S Charge................ \d\ 20 (9.07) Subsurface............ 4 8.................... 32 130 (58.9)
Charge................ \d\ 5 (2.3) Surface............... 10 8.................... 80
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\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 planned 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 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 25.

Table 25--Predicted Dolphin Densities in the Existing LIA and New East
LIA
------------------------------------------------------------------------
Density estimate (animals per
km\2\) \a\
Species -------------------------------
Existing LIA East 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

[[Page 24080]]

of the existing LIA, the SEL threshold distances are the same for the
East LIA, and all missions are conducted in either the existing LIA or
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. Tables 26, 27,
and 28 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 26 and 27, while Table 28 contains
threshold distances for Rice's whale.

Table 26--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
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 27--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

[[Page 24081]]

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 28--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 -------------------------------------------------------------------------------
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
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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.

As discussed previously and shown in Table 21, a portion of the
kinetic energy released by an inert munition at impact is transmitted
as underwater acoustic energy in a pressure impulse. The planned 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 29
presents the impact energy classes developed for the inert munitions.
The four impact energy classes represent the entire suite of inert
munitions planned 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 29 and 30 present the
threshold distances estimated for the dolphins and Rice's whale,
respectively, for inert munitions in the existing LIA.

[[Page 24082]]

Table 29--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 TNTeq) 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
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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 30--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\
injury injury -------------------------------------------------------------------------------
Inert impact class (lb 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 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 East LIA. Should the usage ratio change 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 31--Calculated Annual Exposures of Dolphins Under the USAF's Planned 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.......................
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
-------------------------------------------------------------------------------

[[Page 24083]]

Total....................... 0.14 0.4 0.98 39.06 99.89
-------------------------------------------------------------------------------
Total Takes............. 0 0 1 39 100
----------------------------------------------------------------------------------------------------------------
\a\ Slight lung and/or gastrointestinal tract injury.

The annual exposures of dolphins requested by the USAF and
authorized by NMFS are presented in Table 31. 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 planned 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 25-
29 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 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
mitig

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