Proposed Rule2023-02242
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Testing and Training Operations in the Eglin Gulf Test and Training Range
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
February 7, 2023
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the U.S. Department of the Air Force (USAF) to take marine mammals incidental to testing and training military operations proposed to be conducted in the Eglin Gulf Test and Training Range (EGTTR) from 2023 to 2030 in the Gulf of Mexico. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue regulations and subsequent Letter of Authorization (LOA) to the USAF to incidentally take marine mammals during the specified activities. NMFS will consider public comments prior to issuing any final rule and making final decisions on the issuance of the requested LOA. Agency responses to public comments will be summarized in the notice of the final decision in the final rule. The USAF's activities qualify as military readiness activities pursuant to the MMPA, as amended by the National Defense Authorization Act for Fiscal Year 2004 (2004 NDAA).
Full Text
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<title>Federal Register, Volume 88 Issue 25 (Tuesday, February 7, 2023)</title>
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[Federal Register Volume 88, Number 25 (Tuesday, February 7, 2023)]
[Proposed Rules]
[Pages 8146-8200]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-02242]
[[Page 8145]]
Vol. 88
Tuesday,
No. 25
February 7, 2023
Part III
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Part 218
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental
to Testing and Training Operations in the Eglin Gulf Test and Training
Range; Proposed Rule
Federal Register / Vol. 88, No. 25 / Tuesday, February 7, 2023 /
Proposed Rules
[[Page 8146]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 218
[Docket No. 230127-0029]
RIN 0648-BL77
Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to Testing and Training Operations in the Eglin Gulf Test
and Training Range
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; request for comments and information.
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SUMMARY: NMFS has received a request from the U.S. Department of the
Air Force (USAF) to take marine mammals incidental to testing and
training military operations proposed to be conducted in the Eglin Gulf
Test and Training Range (EGTTR) from 2023 to 2030 in the Gulf of
Mexico. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is
requesting comments on its proposal to issue regulations and subsequent
Letter of Authorization (LOA) to the USAF to incidentally take marine
mammals during the specified activities. NMFS will consider public
comments prior to issuing any final rule and making final decisions on
the issuance of the requested LOA. Agency responses to public comments
will be summarized in the notice of the final decision in the final
rule. The USAF's activities qualify as military readiness activities
pursuant to the MMPA, as amended by the National Defense Authorization
Act for Fiscal Year 2004 (2004 NDAA).
DATES: Comments and information must be received no later than March 9,
2023.
ADDRESSES: Submit all electronic public comments via the Federal e-
Rulemaking Portal. Go to <a href="https://www.regulations.gov">https://www.regulations.gov</a> and enter NOAA-
NMFS-2021-0064 in the Search box. Click on the ``Comment'' icon,
complete the required fields, and enter or attach your comments.
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period,
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
<a href="http://www.regulations.gov">www.regulations.gov</a> without change. All personal identifying
information (e.g., name, address), confidential business information,
or otherwise sensitive information submitted voluntarily by the sender
will be publicly accessible. NMFS will accept anonymous comments (enter
``N/A'' in the required fields if you wish to remain anonymous).
Attachments to electronic comments will be accepted in Microsoft Word,
Excel, or Adobe PDF file formats only.
A copy of the USAF's application and other supporting documents and
documents cited herein may be obtained online at: <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>. In case of problems accessing
these documents, please use the contact listed here (see FOR FURTHER
INFORMATION CONTACT).
FOR FURTHER INFORMATION CONTACT: Robert Pauline, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Purpose of Regulatory Action
These proposed regulations, issued under the authority of the MMPA
(16 U.S.C. 1361 et seq.), would provide the framework for authorizing
the take of marine mammals incidental to the USAF's training and
testing activities (which qualify as military readiness activities)
from air-to-surface operations that involve firing live or inert
munitions, including missiles, bombs, and gun ammunition, from aircraft
at various types of targets on the water surface. Live munitions used
in the EGTTR are set to detonate either in the air a few feet above the
water, instantaneously upon contact with the water or target, or
approximately 5 to 10 feet (ft) (1.5 to 3 meters (m)) below the water
surface. There would also be training exercises for Navy divers that
require the placement of small explosive charges by hand to disable
live mines.
Eglin Air Force Base (AFB) would conduct operations in the existing
Live Impact Area (LIA). In addition, the USAF is also proposing to
create and use a new, separate LIA within the EGTTR that would be used
for live missions in addition to the existing LIA. Referred to as the
East LIA, it is located approximately 40 nautical miles (nmi)/(74
kilometers (km)) southeast of the existing LIA. (See Figure 1).
NMFS received an application from the USAF requesting 7-year
regulations and an authorization to incidentally take individuals of
multiple species of marine mammals (``USAF's rulemaking/LOA
application'' or ``USAF's application''). Take is anticipated to occur
by Level A and Level B harassment incidental to the USAF's training and
testing activities, with no serious injury or mortality expected or
proposed for authorization.
Background
The MMPA prohibits the take of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA direct the
Secretary of Commerce (as delegated to NMFS) to allow, upon request,
the incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, a notice of a proposed authorization is
provided to the public for review and the opportunity to submit
comments.
An authorization for incidental takings shall be granted if NMFS
finds that the taking will have a negligible impact on the species or
stocks and will not have an unmitigable adverse impact on the
availability of the species or stocks for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other means of effecting the least practicable adverse
impact on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stocks for
taking for certain subsistence uses (referred to in this rule as
``mitigation measures''). NMFS also must prescribe the requirements
pertaining to the monitoring and reporting of such takings. The MMPA
defines ``take'' to mean to harass, hunt, capture, or kill, or attempt
to harass, hunt, capture, or kill any marine mammal. The Preliminary
Analysis and Negligible Impact Determination section below discusses
the definition of ``negligible impact.''
The NDAA for Fiscal Year 2004 (2004 NDAA) (Pub. L. 108-136) amended
section 101(a)(5) of the MMPA to remove the ``small numbers'' and
``specified geographical region'' provisions indicated above and
amended the definition of ``harassment'' as applied to a ``military
readiness activity.'' The definition of harassment for military
readiness activities (section 3(18)(B) of the MMPA) is: (i) Any act
that injures or has the significant potential to injure a marine mammal
or marine mammal stock in the wild (Level A Harassment); or (ii) Any
act that disturbs or is likely to disturb a marine mammal or marine
mammal stock in the wild by causing disruption of natural
[[Page 8147]]
behavioral patterns, including, but not limited to, migration,
surfacing, nursing, breeding, feeding, or sheltering, to a point where
such behavioral patterns are abandoned or significantly altered (Level
B harassment). In addition, the 2004 NDAA amended the MMPA as it
relates to military readiness activities such that the least
practicable adverse impact analysis shall include consideration of
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
More recently, section 316 of the NDAA for Fiscal Year 2019 (2019
NDAA) (Pub. L. 115-232), signed on August 13, 2018, amended the MMPA to
allow incidental take rules for military readiness activities under
section 101(a)(5)(A) to be issued for up to 7 years. Prior to this
amendment, all incidental take rules under section 101(a)(5)(A) were
limited to 5 years.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must evaluate our USAF's proposed activities and alternatives with
respect to potential impacts on the human environment. Accordingly,
NMFS plans to adopt the Eglin Gulf Test and Training Range
Environmental Assessment (2022 REA) (USAF 2022), provided our
independent evaluation of the document finds that it includes adequate
information analyzing the effects on the human environment of issuing
regulations and LOAs under the MMPA. NMFS is a cooperating agency on
the 2022 REA and has worked with the USAF developing the document. The
draft 2022 REA was made available for public comment on December 13,
2022 through January 28, 2023. We will review all comments submitted in
response to the request for comments on the 2022 REA and in response to
the request for comments on this proposed rule prior to concluding our
NEPA process or making a final decision on this proposed rule for the
issuance of regulations under the MMPA and any subsequent issuance of a
Letter of Authorization (LOA) to the USAF to incidentally take marine
mammals during the specified activities.
Summary of Request
On January 18, 2022, NMFS received an application from the USAF for
authorization to take marine mammals by Level A and Level B harassment
incidental to training and testing activities (categorized as military
readiness activities) in the EGTTR for a period of 7 years. On June 17,
2022 NMFS received an adequate and complete application for missions
that would include air-to-surface operations that involve firing live
or inert munitions, including missiles, bombs, and gun ammunition from
aircraft at targets on the water surface. The types of targets used
vary by mission and primarily include stationary, remotely controlled,
and towed boats, inflatable targets, and marker flares. Live munitions
used in the EGTTR are set to detonate either in the air a few feet
above the water surface (airburst detonation), instantaneously upon
contact with the water or target (surface detonation), or approximately
5 to 10 feet (1.5 to 3 m) below the water surface (subsurface
detonation). On July 17, 2022, we published a notice of receipt (NOR)
of application in the Federal Register (87 FR 42711), requesting
comments and information related to the USAF's request. The public
comment period was open for 30 days. We reviewed and considered all
comments and information received on the NOR in development of this
proposed rule.
On February 8, 2018, NMFS promulgated a rulemaking and issued an
LOA for takes of marine mammals incidental to Eglin AFB's training and
testing operations in the EGTTR (83 FR 5545). Current EGTTR operations
are authorized under the 2018 EGTTR LOA which will expire on February
12, 2023. Under this proposed rulemaking action, the EGTTR would
continue to be used during the next mission period based on the
maritime training and testing requirements of the various military
units that use the EGTTR. The next mission period would span 7 years,
from 2023 to 2030. Most operations during this period would be a
continuation of the same operations conducted by the same military
units during the previous mission period. There would, however, be an
increase in the annual quantities of all general categories of
munitions (bombs, missiles, and gun ammunition) under the USAF's
proposed activities, except for live gun ammunition, which is proposed
to be used less over the next mission period. The highest net explosive
weight (NEW) of the munitions under the USAF's proposed activities
would be 945 pounds (lb) (430 kilograms (kg), which was also the
highest NEW for the previous mission period. Live missions proposed for
the 2023-2030 period would be conducted in the existing Live Impact
Area (LIA) within the EGTTR. Certain missions may also be conducted in
the proposed East LIA, which would be a new, separate area within the
EGTTR where live munitions would be used. The USAF's rulemaking/LOA
application reflects the most up-to-date compilation of training and
testing activities deemed necessary to accomplish military readiness
requirements. EGTTR training and testing operations are critical for
achieving military readiness and the overall goals of the National
Defense Strategy. The regulations proposed in this action, if issued,
would be effective for seven years, beginning from the date of
issuance.
Description of the Proposed Activity
The USAF requests authorization to take marine mammals incidental
to conducting training and testing activities. The USAF has determined
that acoustic and explosives stressors are most likely to result in
impacts on marine mammals that could qualify as take under the MMPA,
and NMFS concurs with this determination. Eglin AFB proposes to conduct
military aircraft missions within the EGTTR that involve the employment
of multiple types of live (explosive) and inert (non-explosive)
munitions (i.e., missiles, bombs, and gun ammunition) against various
surface targets. Munitions may be delivered by multiple types of
aircraft including, but not limited to, fighter jets, bombers, and
gunships.
Detailed descriptions of these activities are described in the
Eglin Gulf Test and Training Range (EGTTR) Range Environmental
Assessment (REA) (USAF 2022), currently under preparation as well as
the USAF's rulemaking/LOA application. (<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>). A summary of the proposed activities and are presented
below.
Dates and Duration
The specified activities would occur at any time during the 7-year
period of validity of the regulations. The proposed amount of training
and testing activities are described in the Detailed Description of the
Specified Activities section.
Geographical Region
The Eglin Military Complex encompasses approximately 724 square
miles (1,825 km\2\ of land in the Florida Panhandle and consists of the
Eglin Reservation in Santa Rosa, Okaloosa, and Walton Counties, and
property on Santa Rosa Island and Cape San Blas. The EGTTR is the
airspace controlled by Eglin AFB over the Gulf of Mexico, beginning 3
nautical miles (nmi) (5.56
[[Page 8148]]
km) from shore, and the underlying Gulf of Mexico waters. The EGTTR
extends southward and westward off the coast of Florida and encompasses
approximately 102,000 nmi (349,850 km\2\). It is subdivided into blocks
of airspace that consist of Warning Areas W-155, W-151, W-470, W-168,
and W-174 and Eglin Water Test Areas 1 through 6 (Figure 1). Most of
the blocks are further subdivided into smaller airspace units for
scheduling purposes (for example, W-151A, B, C, and D). Although Eglin
AFB may use any portion of the EGTTR, the majority of training and
testing operations proposed for the 2023-2030 mission period would
occur in Warning Area W-151. The nearshore boundary of W-151 parallels
much of the coastline of the Florida Panhandle and extends horizontally
from 3 nmi (5.56 km) offshore to approximately 85 to 100 nmi (158 to185
km) to offshore, depending on the specific portion of its outer
boundary. W-151 encompasses approximately 10,247 nmi\2\ (35146 km\2\)
and includes water depths that range from approximately 5 to 720 m. The
existing LIA, which is the portion of the EGTTR where the use of live
munitions is currently authorized, lies mostly within W-151. The
existing LIA encompasses approximately 940 nmi\2\ (3,224 km\2\ and
includes water depths that range from approximately 30 to 145 m (Figure
2). This is where live munitions within the EGTTR are currently used in
the existing LOA (83 FR 5545; February 8, 2018) and where the Gulf
Range Armament Test Vessel (GRATV) is anchored. The GRATV remains
anchored at a specific location during a given mission; however, it is
mobile and relocated within the LIA based on mission needs.
The USAF's proposed activities provide for the creation of a new,
separate area within the EGTTR that would be used for live missions in
addition to the existing LIA. This area, herein referred to as the East
LIA, would be located approximately 40 NM offshore of Eglin AFB
property on Cape San Blas. Cape San Blas is located on St. Joseph
Peninsula in Gulf County, Florida, approximately 90 mi (144 km)
southeast of the Eglin Reservation. Eglin AFB facilities on Cape San
Blas remotely support EGTTR operations via radar tracking, telemetry,
and other functions. The proposed East LIA would be circular-shaped and
have a radius of approximately 10 nmi (18.5 km) and a total area of
approximately 314 NM \2\. Water depths range from approximately 35 to
95 m. The general location of the proposed East LIA is shown in Figure
2. Establishment of the East LIA would allow Eglin AFB to maximize the
flight range for large-footprint weapons and minimize the distance,
time, and cost of deploying support vessels and targets. Based on these
factors, the East LIA would allow testing of weapon systems and flight
profiles that cannot be conducted within the constraints of the
existing LIA.
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Detailed Description of the Specified Activities
This section provides descriptions of each military user group's
proposed EGTTR operations, as well as information regarding munitions
proposed to be used during the operations. This information includes
munition type, category, net explosive weight (NEW), detonation
scenario, and annual quantity proposed to be expended in the EGTTR. NEW
applies only to live munitions and is the total mass of the explosive
substances in a given munition, without packaging, casings, bullets, or
other non-explosive components of the munition. Note that for some
munitions the warhead is removed and replaced with a telemetry package
that tracks the munition's path and/or Flight Termination System (FTS)
that ends the flight of the munition in a controlled manner. These
munitions have been categorized as live munitions with NEWs that range
from 0.30 to 0.70
[[Page 8151]]
lb (0.13 to 0.31 kg) While certain munitions with only FTS may be
considered inert due to negligible NEW, those contained here are
considered to be live with small amounts of NEW. The detonation
scenario applies only to live munitions which are set to detonate in
one of three ways: (1) in the air a few feet above the water surface,
referred to as airburst or height of burst (HOB); (2) instantaneously
upon contact with the water or target on the water surface; or (3)
after a slight delay, up to 10 milliseconds, after impact, which would
correspond to a subsurface detonation at a water depth of approximately
5 to 10 ft (1.5 to 3 m). Estimated take is only modeled for scenarios
(2) and (3). The proposed annual expenditures of munitions are the
quantities determined necessary to meet the mission requirements of the
user groups.
Live missions proposed for the 2023-2030 period would be conducted
in the existing LIA and potentially in the proposed East LIA, depending
on the mission type and objectives. Live missions that involve only
airburst or aerial target detonations would continue to be conducted in
or outside the LIA in any portion of the EGTTR; such detonations have
no appreciable effect on marine mammals because there is negligible
transmission of pressure or acoustic energy across the air-water
interface. Use of inert munitions and live air-to-surface gunnery
operations would also continue to occur in or outside the LIA, subject
to proposed mitigation and monitoring measures.
Eglin AFB proposes the following actions in the EGTTR which would
be conducted in the existing LIA and potentially in the proposed East
LIA, depending on the mission type and objectives:
(1) 53rd Weapons Evaluation Group missions that involve air-to-
ground Weapons System Evaluation Program (WSEP) known as Combat Hammer
which tests various types of munitions against small target boats and
air-to-air missile testing known as Combat Archer;
(2) Continuation of the Air Force Special Operations Command
(AFSOC) training missions in the EGTTR primarily involving air-to-
surface gunnery, bomb, and missile exercises including AC-130 gunnery
training, CV-22 training, and bomb and missile training;
(3) 96th Operations Group missions including AC-130 gunnery testing
against floating marker targets on the water surface, MQ-9 air-to-
surface testing, and 780th Test Squadron Precision Strike Weapons
testing including air-launched cruise missile tests, air-to-air missile
tests, Longbow and Joint Air-to-Ground Missile (JAGM) testing; Spike
Non-Line-of-Sight (NLOS) air-to-surface missile testing, Patriot
missile testing, Hypersonic Weapon Testing, sink at-sea live-fire
training exercises (SINKEX), and testing using live and inert munitions
against targets on the water surface; and
(4) Naval School Explosive Ordnance Disposal (NAVSCOLEOD) training
missions that involve students diving and placing small explosive
charges adjacent to inert mines.
53rd Weapons Evaluation Group
The 53rd Weapons Evaluation Group (53 WEG) conducts the USAF's air-
to-ground Weapons System Evaluation Program (WSEP). The Combat Hammer
program involves testing various types of live and inert munitions
against small target boats. This testing is conducted to develop
tactics, techniques, and procedures (TTP) to be used by USAF aircraft
to counter small, maneuvering, hostile vessels. Combat Hammer missions
proposed in the EGTTR for the 2023-2030 period would involve the use of
several types of aircraft, including F-15, F-16, F-18, F-22, F-35, and
A-10 fighter aircraft, AC-130 gunships, B-1, B-2, and B-52 bomber
aircraft, and MQ-1 and MQ-9 drone aircraft. USAF, Air National Guard,
and U.S. Navy units would support these missions. Live munitions would
be deployed against static (anchored), remotely controlled, and towed
targets. Static and remotely controlled targets would consist of
stripped boat hulls with simulated systems and, in some cases, heat
sources. Various types of live and inert munitions are used during
Combat Hammer missions in the EGTTR, including missiles, bombs, and gun
ammunition. Table 1 presents information on the munitions proposed for
Combat Hammer missions in the EGTTR during the 2023-2030 period.
Table 1--Proposed Munitions for WSEP Combat Hammer Missions in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Destination
Type Category weight (lb)/(kg) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
AGR-20...................... Rocket............. 9.1 (4.1) Surface............ 12
AGM-158D JASSM XR........... Missile............ 240.26 (108.9) Surface............ 4
AGM-158B JASSM ER........... Missile............ 240.26 (108.9) Surface............ 3
AGM-158A JASSM.............. Missile............ 240.26 (108.9) Surface............ 3
AGM-65D..................... Missile............ 150 (68) Surface............ 5
AGM-65G2.................... Missile............ 145 (65.7) Surface............ 5
AGM-65H2.................... Missile............ 150 (68) Surface............ 5
AGM-65K2.................... Missile............ 145 (65.7) Surface............ 4
AGM-65L..................... Missile............ 150 (68) Surface............ 5
AGM-114 N-6D with TM........ Missile............ 29.1 (13.2) Surface............ 4
AGM-114 N-4D with TM........ Missile............ 29.94 (13.6) Surface............ 4
AGM-114 R2 with TM (R10).... Missile............ 27.41 (12.4) Surface............ 4
AGM-114 R-9E with TM (R11).. Missile............ 27.38 (12.4) Surface............ 4
AGM-114Q with TM............ Missile............ 20.16 (9.1) Surface............ 4
CBU-105D.................... Bomb............... 108.6 (49.5) HOB................ 8
GBU-53/B (GTV).............. Bomb............... 0.34(0.1)\a\ HOB/Surface........ 8
GBU-39 SDB (GTV)............ Bomb............... 0.39(0.1)\a\ Surface............ 4
AGM-88C w/FTS............... Missile............ 0.70 (0.31)\a\ Surface............ 2
AGM-88B w/FTS............... Missile............ 0.70 (0.31)\a\ Surface............ 2
AGM-88F w/FTS............... Missile............ 0.70(0.31)\a\ Surface............ 2
AGM-88G w/FTS............... Missile............ 0.70(0.31)\a\ Surface............ 2
AGM-179 JAGM................ Missile............ 27.47(12.5) Surface............ 4
GBU-69...................... Bomb............... 6.88 (3.1) Surface............ 2
GBU-70...................... Bomb............... 6.88 (3.1) Surface............ 4
[[Page 8152]]
AGM-176..................... Missile............ 8.14 (3.7) Surface............ 4
GBU-54 KMU-572C/B........... Bomb............... 193 (87.5) Surface............ 4
GBU-54 KMU-572B/B........... Bomb............... 193 Surface............ 4
PGU-43 (105 mm)............. Gun Ammunition..... 4.7 Surface............ 100
Inert Munitions:
ADM-160B MALD............... Missile............ N/A N/A................ 4
ADM-160C MALD-J............. Missile............ N/A N/A................ 4
ADM-160C-1 MALD-J........... Missile............ N/A N/A................ 4
ADM-160D MALD-J............. Missile............ N/A N/A................ 4
GBU-10...................... Bomb............... N/A N/A................ 8
GBU-12...................... Bomb............... N/A N/A................ 32
GBU-49...................... Bomb............... N/A N/A................ 16
GBU-24/B (84)............... Bomb............... N/A N/A................ 16
GBU-24A/B (109)............. Bomb............... N/A N/A................ 2
GBU-31B(v)1................. Bomb............... N/A N/A................ 16
GBU-31C(v)1................. Bomb............... N/A N/A................ 16
GBU-31B(v)3................. Bomb............... N/A N/A................ 2
GBU-31C(v)3................. Bomb............... N/A N/A................ 2
GBU-32C..................... Bomb............... N/A N/A................ 8
GBU-38B..................... Bomb............... N/A N/A................ 4
GBU-38C w/BDU-50 (No TM).... Bomb............... N/A N/A................ 4
GBU-38C..................... Bomb............... N/A N/A................ 10
GBU-54 KMU-572C/B........... Bomb............... N/A N/A................ 4
GBU-54 KMU-572B/B........... Bomb............... N/A N/A................ 4
GBU-69...................... Bomb............... N/A N/A................ 2
BDU-56A/B................... Bomb............... N/A N/A................ 4
PGU-27 (20 mm).............. Gun Ammunition..... 0.09 (0.04) N/A................ 16,000
PGU-15 (30 mm).............. Gun Ammunition..... N/A N/A................ 16,000
PGU-25 (25 mm).............. Gun Ammunition..... N/A N/A................ 16,000
ALE-50...................... Decoy System....... N/A N/A................ 6
----------------------------------------------------------------------------------------------------------------
\a\ Warhead replaced by FTS/TM. Identified NEW is for the FTS.
ADM = American Decoy Missile; AGM = Air-to-Ground Missile; ALE = Ammunition Loading Equipment; BDU = Bomb Dummy
Unit; CBU = Cluster Bomb Unit; EGTTR = Eglin Gulf Test and Training Range; ER = Extended Range; FTS = Flight
Termination System; GBU = Guided Bomb Unit; GTV = Guided Test Vehicle; HOB = height of burst; JAGM = Joint Air-
to-Ground Missile; JASSM = Joint Air-to-Surface Standoff Missile; lb = pound(s); MALD = Miniature Air-Launched
Decoy; mm = millimeter(s); N/A = not applicable; PGU = Projectile Gun Unit; SDB = Small-Diameter Bomb, TM =
telemetry; WSEP = Weapons System Evaluation Program.
The Combat Archer program involves live air-to-air missile testing
in the EGTTR. Combat Archer missions also include firing inert gun
ammunition and releasing flares and chaff from aircraft. Air-to-air
missile testing during these missions specifically involves firing live
AIM-9 Sidewinder and AIM-120 Advanced Medium-Range Air-to-Air Missiles
(AMRAAMs) at BOM-167 Subscale Aerial Targets and QF-16 Full-Scale
Aerial Targets to evaluate the effectiveness of missile delivery
techniques. Combat Archer missions involve the use of several types of
fighter aircraft, including the F-15, F-16, F-18, F-22, F-35, and A-10.
Table 2 presents information on the munitions proposed to be used
during Combat Archer missions in the EGTTR.
Table 2--Proposed Munitions for Combat Archer Missions in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Type Category weight (lb)/(kg) Detonation scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
AIM-120D.................... Missile............ 113.05 (51.3) HOB................ 24
AIM-120C7................... Missile............ 113.05 (51.3) HOB................ 10
AIM-120C5/6................. Missile............ 113.05 (51.3) HOB................ 8
AIM-120C3................... Missile............ 102.65 (46.5) HOB................ 14
AIM-120C3................... Missile............ 117.94 (63.5) HOB/Surface........ 4
AIM-120B.................... Missile............ 102.65 (46.5) HOB................ 18
AIM-9X Blk I................ Missile............ 60.25 (27.3) HOB................ 7
AIM-9X Blk I................ Missile............ 67.9 (30.8) HOB/Surface........ 10
AIM-9X Blk II............... Missile............ 60.25 (27.3) HOB................ 24
AIM-9M-9.................... Missile............ 60.55 (27.3) HOB................ 90
Inert Munitions:
AIM-260A JATM............... Missile............ N/A N/A................ 4
PGU-27 (20 mm).............. Gun Ammunition..... N/A N/A................ 80,000
PGU-23 (25 mm).............. Gun Ammunition..... N/A N/A................ 6,000
MJU-7A/B Flare.............. Flare.............. N/A N/A................ 1,800
R-188 Chaff................. Chaff.............. N/A N/A................ 6,000
[[Page 8153]]
R-196 (T-1) Chaff........... Chaff.............. N/A N/A................ 1,500
----------------------------------------------------------------------------------------------------------------
AIM = Air Intercept Missile; EGTTR = Eglin Gulf Test and Training Range; HOB = height of burst; JATM = Joint
Advanced Tactical Missile; lb = pound(s); MJU = Mobile Jettison Unit; mm = millimeter(s); N/A = not
applicable; PGU = Projectile Gun Unit; WSEP = Weapons System Evaluation Program.
Air Force Special Operations Command Training
The Air Force Special Operations Command (AFSOC) proposes to
continue conducting training missions during the 2023-2030 period.
These missions primarily involve air-to-surface gunnery, bomb, and
missile exercises. Gunnery training in the EGTTR involves firing live
rounds from AC-130 gunships at targets on the water surface. Gun
ammunition used for this training primarily includes 30-millimeter (mm)
High Explosive (HE) and 105 mm HE rounds. A standard 105 mm HE round
has a NEW of 4.7 lb. The Training Round (TR) variant of the 105 mm HE
round, which has a NEW of 0.35 lb, is used by AFSOC for nighttime
missions. This TR was developed to have less explosive material to
minimize potential impacts to protected marine species, which could not
be adequately surveyed at night by earlier aircraft instrumentation.
Since the development of the 105 mm HE TR, AC-130s have been equipped
with low-light electro-optical and infrared sensor systems that provide
excellent night vision. Targets used for AC-130 gunnery training
include Mark (Mk)-25 marine markers and inflatable targets. During each
gunnery training mission, gun firing can last up to 90 minutes but
typically lasts approximately 30 minutes. Live firing is continuous,
with pauses usually lasting well under 1 minute and rarely up to 5
minutes. Table 3 presents information on the rounds proposed for AC-130
gunnery training by AFSOC.
Table 3--Proposed Rounds for AC-130 Gunnery Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation Number of Rounds per Annual
Type weight (lb)/(kg) scenario missions mission quantity
----------------------------------------------------------------------------------------------------------------
Daytime Missions:
105 mm HE (FU).......... 4.7 (2.1) Surface........ 25 30 750
30 mm HE................ 0.1 (0.04) 500 12,500
Nighttime Missions:
105 mm HE (TR).......... 0.35 (0.2 Surface........ 45 30 1,350
30 mm HE................ 0.1 (0.04) 500 22,500
------------------- -----------------------------------------------
Total............... ................. ............... 70 .............. 37,100
----------------------------------------------------------------------------------------------------------------
EGTTR = Eglin Gulf Test and Training Range; FU = Full Up; HE = High Explosive; mm = millimeter(s); lb =
pound(s); TR = Training Round.
The 8th Special Operations Squadron (8 SOS) under AFSOC conducts
training in the EGTTR using the tiltrotor CV-22 Osprey. This training
involves firing .50 caliber rounds from CV-22s at floating marker
targets on the water surface. The .50 caliber rounds do not contain
explosive material and, therefore, do not detonate. Flight procedures
for CV-22 training are similar to those described for AC-130 gunnery
training, except that CV-22 aircraft typically operate at much lower
altitudes (100 to 1,000 feet (30.48 to 304.8 m) (AGL) than AC-130
gunships (6,000 to 20,000 feet (1,828 to6,96 m) AGL). Like AC-130
gunships, CV-22s are equipped with highly sophisticated electro-optical
and infrared sensor systems that allow advanced detection capability
during day and night. Table 4 presents information on the rounds
proposed for CV-22 training missions.
Table 4--Proposed Rounds for CV-22 Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation Number of Rounds per Annual
Type weight (lb) scenario missions mission quantity
----------------------------------------------------------------------------------------------------------------
Daytime Missions:
.50 Caliber............. N/A Surface........ 25 600 15,000
Nighttime Missions:
.50 Caliber............. N/A Surface........ 25 600 15,000
----------------- -------------------------------
Total............... ................. ............... .............. 50 30,000
----------------------------------------------------------------------------------------------------------------
In addition to AC-130 gunnery and CV-22 training, AFSOC also
conducts other air-to-surface training in the EGTTR using various types
of bombs and missiles as shown in Table 5. This training is conducted
primarily to develop TTPs and train strike aircraft to counter small
moving boats. Munitions used for this training primarily include live
AGM-176 Griffin missiles, live AGM-114 Hellfire missiles, and various
types of live and inert bombs. These
[[Page 8154]]
munitions are launched from various types of aircraft against small
target boats, and they either detonate on impact with the target or at
a programmed HOB.
Table 5--Proposed Munitions for AFSOC Bomb and Missile Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive weight Detonation
Type Category (lb)(kg) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
AGM-176 Griffin.......... Missile........ 4.58 (2.1) HOB............ 100
AGM-114R9E/R2 Hellfire... Missile........ 20.0 (9.07) HOB............ 70
2.75-inch Rocket Rocket......... 2.3 (1.0) Surface........ 400
(including APKWS).
GBU-12................... Bomb........... 198.0 (89.8)/298.0 (135.1) Surface........ 30
Mk-81 (GP 250 lb)........ Bomb........... 151.0 (98.4) Surface........ 30
GBU-39 (SDB I)........... Bomb........... 37.0 (16.7) HOB............ 30
GBU-69................... Bomb........... 36.0 (16.3) HOB............ 40
Inert Munitions:
.50 caliber.............. Gun Ammunition. N/A N/A............ 30,000
GBU-12................... Bomb........... N/A N/A............ 30
MkK-81 (GP 250 lb)....... Bomb........... N/A N/A............ 30
BDU-50................... Bomb........... N/A N/A............ 30
BDU-33................... Bomb........... N/A N/A............ 50
----------------------------------------------------------------------------------------------------------------
AFSOC = Air Force Special Operations Command; AGM = Air-to-Ground Missile; APKWS = Advanced Precision Kill
Weapon System; BDU = Bomb Dummy Unit; EGTTR = Eglin Gulf Test and Training Range; GBU = Guided Bomb Unit; GP =
General Purpose; HOB = height of burst; lb = pound(s); Mk = Mark; N/A = not applicable; SDB = Small-Diameter
Bomb.
96th Operations Group
Three units under the 96th Operations Group (96 OG) propose to
conduct missions in the EGTTR during the 2023-2030 period: the 417th
Flight Test Squadron (417 FLTS), the 96th Operational Support Squadron
(96 OSS), and the 780th Test Squadron (780 TS).
The 417 FLTS proposes to continue conducting AC-130 testing in the
EGTTR to evaluate the capabilities of the Precision Strike Package
(PSP), Stand Off Precision Guided Munitions (SOPGM), and other systems
on AC-13O aircraft. AC-130 gunnery testing is generally similar to
activities previously described for AFSOC AC-130 gunnery training.
Table 6 presents information on the munitions proposed for AC-130
testing in the EGTTR during the 2023-2030 mission period.
Table 6--Proposed Rounds for AC-130 Gunnery Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Type Category weight (lb)/(kg) Detonation scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
AGM-176 Griffin............. Missile............ 4.58 (2.1) Surface............ 10
AGM-114 Hellfire............ Missile............ 20.0 (9.1) Surface............ 10
GBU-39 (SDB I).............. Bomb............... 37.0 (16.8) Surface............ 6
GBU-39 (LSDB)............... Bomb............... 37.0 (16.8) Surface............ 10
105 mm HE (FU).............. Gun Ammunition..... 4.7 (2.1) Surface............ 60
105 mm HE (TR).............. Gun Ammunition..... 0.35 (0.2) Surface............ 60
30 mm HE.................... Gun Ammunition..... 0.1 (0.1) Surface............ 99
----------------------------------------------------------------------------------------------------------------
AGM = Air-to-Ground Missile; EGTTR = Eglin Gulf Test and Training Range; FU = Full Up; GBU = Guided Bomb Unit;
HE = High Explosive; lb = pound(s); mm = millimeter(s); LSDB = Laser Small-Diameter Bomb; SDB = Small-Diameter
Bomb; TR = Training Round.
The 96 OSS proposes to conduct air-to-surface testing in the EGTTR
using assorted live missiles and live and inert precision-guided bombs
to support testing requirements of the MQ-9 Reaper unmanned aerial
vehicle (UAV) program. The proposed munitions would be tested for MQ-9
integration and would include captive carry and munitions employment
tests. During munition employment tests, the proposed munitions would
be launched from MQ-9 aircraft at various types of static and moving
targets on the water surface. Table 7 presents information on the
munitions proposed by the 96 OSS for MQ-9 testing in the EGTTR.
Table 7--Proposed Munitions for MQ-9 Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive
Type Category weight (lb)/(kg) Detonation scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
AGM-114R Hellfire........... Missile............ 20.0 (9.1) Surface............ 36
AIM-9X...................... Missile............ 7.9 (3.6) HOB................ 1
[[Page 8155]]
GBU-39B/B LSDB.............. Bomb............... 37.0 (16.8) Surface............ 2
Inert Munitions:
GBU-39B/B LSDB.............. Bomb............... N/A N/A................ 2
GBU-49...................... Bomb............... N/A N/A................ 10
GBU-48...................... Bomb............... N/A N/A................ 1
----------------------------------------------------------------------------------------------------------------
AGM = Air-to-Ground Missile; AIM = Air Intercept Missile; EGTTR = Eglin Gulf Test and Training Range; GBU =
Guided Bomb Unit; lb = pound(s); LSDB = Laser Small-Diameter Bomb.
The 780 TS, the Air Force Life Cycle Management Center, and the
U.S. Navy jointly conduct Precision Strike Weapons (PSW) test missions
in the EGTTR. These missions use the AGM-158 JASSM and GBU-39 SDB
precision-guided bomb. The JASSM is an air-launched cruise missile with
a range of more than 200 nmi (370 km). During test missions, the JASSM
would be launched from aircraft more than 200 nmi (370 km) from the
target location at altitudes greater than 25,000 ft (7,620 m) km above
ground level (AGL). The JASSM would cruise at altitudes greater than
12,000 ft (3,657 m) AGL for most of the flight profile until its
terminal descent toward the target. The GBU-39 SDB is a precision-
guided glide bomb with a range of more than 50 nmi (92.6 km). This bomb
would be launched from aircraft more than 50 nmi (92.6 km) from the
target location at altitudes greater than 5,000 ft (1,524 m) AGL. The
bomb would travel via a non-powered glide to the intended target.
Instrumentation in the bomb self-controls the bomb's flight path. Live
JASSMs would detonate at a HOB of approximately 5 ft (0.30 m); however,
these detonations are assumed to occur at the surface for the impact
analysis. The SDBs would detonate either at a HOB of approximately 7 to
14 ft (2.1 to 4.2 m) or upon impact with the target (surface). For
simultaneous SDB launches, two SDBs would be launched from the same
aircraft at approximately the same time to strike the same target. The
SDBs would strike the target within approximately 5 seconds or less of
each other. Such detonations would be considered a single event, with
the associated NEW being doubled for a conservative impact analysis.
Two types of targets are typically used for PSW tests: Container
Express (CONEX) targets and hopper barge targets. CONEX targets
typically consist of up to five CONEX containers strapped, braced, and
welded together to form a single structure. A hopper barge is a common
type of barge that cannot move itself; a typical hopper barge measures
approximately 30 ft (9.1 m) by 12 ft (3.6 m) by 125 ft (38.1 m).
Other SDB tests in the EGTTR during the 2023-2030 mission period
may include operational testing of the GBU-53 (SDB II). These tests may
involve live and inert testing of the munition against target boats.
Table 8 presents information on the munitions proposed for PSW
missions in the EGTTR during the 2023-2030 period.
Table 8--Proposed Munitions for Precision Strike Weapon Missions
----------------------------------------------------------------------------------------------------------------
Net explosive
Type Category weight (lb)/(kg) Detonation scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
AGM-158 (JASSM)............. Missile............ 240.26 (108.9) Surface............ 2
GBU-39 (SDB I).............. Bomb............... 37.0 (16.8) HOB/Surface........ 2
GBU-39 (SDB I) Simultaneous Bomb............... 74.0 (33.35) HOB/Surface........ 2
Launch\a\.
GBU-53 (SDB II)............. Bomb............... 22.84 (10.4) HOB/Surface........ 2
Inert Munitions:
AGM-158 (JASSM)............. Missile............ N/A N/A................ 4
GBU-39 (SDB I).............. Bomb............... N/A N/A................ 4
GBU-39 (SDB I) Simultaneous Bomb............... N/A N/A................ 4
Launch.
GBU-53 (SDB II)............. Bomb............... N/A N/A................ 1
----------------------------------------------------------------------------------------------------------------
\a\ NEW is doubled for simultaneous launch.
AGM = Air-to-Ground Missile; EGTTR = Eglin Gulf Test and Training Range; GBU = Guided Bomb Unit; HOB = height of
burst; JASSM = Joint Air-to-Surface Standoff Missile; lb = pound(s); N/A = not applicable; SDB = Small-
Diameter Bomb.
The 780 TS, along with the Air Force Life Cycle Management Center
and U.S. Navy, propose to jointly conduct air-to-air missile testing in
the EGTTR. These missions would involve the use of the AIM-260A Joint
Advanced Tactical Missile (JATM), AIM-9X Sidewinder, and AIM-120 AMRAAM
missiles; all missiles used in these tests would be inert. Table 9
presents information on the munitions proposed for air-to-air missile
testing missions in the EGTTR during the 2023-2030 mission period.
[[Page 8156]]
Table 9--Proposed Munitions for Air-to-Air Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation
Type Category weight (lb) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
AIM-260 JATM--Inert............. Missile............ N/A N/A................ 6
AIM-9X--Inert................... Missile............ N/A N/A................ 10
AIM-120 AMRAAM--Inert........... Missile............ N/A N/A................ 15
----------------------------------------------------------------------------------------------------------------
AIM = Air Intercept Missile; AMRAAM = Advanced Medium-Range Air-to-Air Missile; EGTTR = Eglin Gulf Test and
Training Range; lb = pound(s); JATM = Joint Advanced Tactical Missile; N/A = not applicable.
The 780 TS proposes to test the ability of the AGM-114L Longbow
missile and AGM-179A Joint Air-to-Ground Missile (JAGM) missile to
track and impact moving target boats in the EGTTR as shown in Table 10.
These missiles are typically launched from an AH-64D Apache helicopter.
The test targets would be remotely controlled boats, including the 25-
foot High-Speed Maneuverable Surface Target (HSMST) (foam filled) and
41-foot (12.5 m) Coast Guard Utility Boat (metal hull). The missiles
would be launched approximately 0.9 to 4.3 nmi (1.7 to 7.9 km) from the
targets.
Table 10--Proposed Munitions for Longbow and JAGM Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation
Type Category weight (lb)/(kg) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
AGM-114L Longbow................ Missile............ 35.95 (16.3) HOB................ 6
AGM-179A JAGM................... Missile............ 27.47 (11.1) HOB................ 8
----------------------------------------------------------------------------------------------------------------
AGM = Air-to-Ground Missile; EGTTR = Eglin Gulf Test and Training Range; HOB = height of burst; JAGM = Joint Air-
to-Ground Missile; lb = pound(s).
The 780 TS proposes to test the Spike Non-Line-of-Sight (NLOS) air-
to-surface tactical missile system against static and moving target
boats in the EGTTR in support of the U.S. Army's initiative to
incorporate the Spike NLOS missile system onto the AH-64E Apache
helicopter. These missiles shown in Table 11 would be launched from an
AH-64D Apache helicopter and the test targets would include foam-filled
fiberglass boats approximately 25 ft (7.62 m) in length that are either
anchored or towed by a remotely controlled (HSMST).
Table 11--Proposed Munitions for NLOS Spike Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation
Type Category weight (lb)/(kg) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Spike NLOS...................... Missile........... 34.08 (14.5) Surface........... 3
----------------------------------------------------------------------------------------------------------------
The 780 TS proposes to conduct surface-to-air testing of Patriot
Advanced Capability (PAC)-2 and PAC-3 missiles in the EGTTR. These
missiles are expected to be fired from the A-15 launch site on Santa
Rosa Island at drones in the EGTTR. Detailed operational data for this
testing are not yet available. Standard inventory missiles would be
used and up to eight PAC-2 tests and two PAC-3 tests per year are
proposed as shown in Table 12.
Table 12--Proposed Munitions for Patriot Missile Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation
Type Category weight (lb)/(kg) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
PAC-2........................... Missile............ \a\145.0 (65.7) N/A (drone target). 8
PAC-3........................... Missile............ \a\145.0 (65.7) N/A (drone target). 2
----------------------------------------------------------------------------------------------------------------
\a\ Assumed for impact analysis.
Hypersonic weapons are capable of traveling at least five times the
speed of sound, referred to as Mach 5. While conventional weapons
typically rely on explosive warheads to inflict damage on a target,
hypersonic weapons typically rely on kinetic energy from high-velocity
impact to inflict damage on targets. For the purpose of assessing
impacts, the kinetic energy of a hypersonic weapon may be correlated to
energy release in units of feet-lb or trinitrotoluene (TNT)
equivalency.
The 780 TS supports several hypersonic weapon programs, including
the Hypersonic Attack Cruise Missile (HACM) and Precision Strike
Missile (PrSM) programs, which are presented in Table 13.
HACM is a developmental air-breathing hypersonic cruise missile
that uses scramjet technology for propulsion. This weapon would air-
launched. The 780 TS proposes to conduct HACM
[[Page 8157]]
testing, which would involve air launches through a north-south
corridor within the EGTTR to a target location on the water surface.
The dimensions and orientation of the test flight corridor within the
EGTTR for HACM tests are to be determined; the flight corridor is
preliminarily expected to be 300 to 400 nmi (555 to 740 km) in total
length. Live HACMs would be fired from the southern portion of the
EGTTR into either the existing LIA or proposed East LIA. Up to two live
HACMs per year are proposed to be tested in the EGTTR during the 2023-
2030 mission period.
The PrSM is being developed by the U.S. Army as a surface-to-
surface, long-range, precision-strike guided missile to be fired from
the M270A1 Multiple Launch Rocket System and the M142 High Mobility
Artillery Rocket System. The 780 TS in coordination with the U.S. Army
proposes to conduct PrSM testing in the EGTTR. Some PrSM testing is
expected to involve surface launches of the PrSM from the A-15 launch
site on Santa Rosa Island. The dimensions and orientation of the test
flight corridor within the EGTTR for PrSM tests are to be determined;
the flight corridor is preliminarily expected to be 162 to 270 nmi (300
to 500 km) in total length. For tests that involve a live warhead on
the PrSM, the PrSM would be preset to detonate at a specific height
above the water surface (HOB/airburst) and could occur in any portion
of the EGTTR. Any surface strikes proposed with live PrSMs would be
required to be in the existing LIA or proposed East LIA. Like inert
HACM tests, inert PrSM tests could occur in any portion of the EGTTR,
except between the 100-m and 400-m isobaths to prevent impacts to the
Rice's whale.
Table 13--Proposed Munitions for Hypersonic Weapon Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation
Type Category weight (lb)/(kg) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Live Munitions:
HACM........................ Hypersonic Weapon.. \a\350 (158.7) Surface............ 2
PrSM........................ Hypersonic Weapon.. \a\46 (158.7) HOB................ 2
Inert Munitions:
PrSM--Inert................. Hypersonic Weapon.. N/A N/A................ 2
----------------------------------------------------------------------------------------------------------------
\a\ Net explosive weight at impact/detonation.
The 780 TS, in coordination with the Air Force Research Laboratory,
proposes to conduct SINKEX testing in the EGTTR. SINKEX exercises would
involve the sinking of vessels, typically 200-400 ft (61 -122 m) in
length, in the existing LIA. The types of munitions that would be used
for SINKEX testing is controlled information and, therefore, not
identified (Table 14).
Table 14--Proposed SINKEX Exercises in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation
Type Category weight (lb) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
SINKEX.......................... Vessel Sinking Not Available..... Not Available..... 2
Exercise.
----------------------------------------------------------------------------------------------------------------
The 780 TS plans to lead or support other types of testing in the
EGTTR as shown in Table 15. These missions would primarily include
testing live and inert munitions against targets on the water surface,
such as boats and barges. Some of the tests would involve munitions
with NEWs of up to 945 lb, which is the highest NEW associated with the
munitions analyzed in this LOA application.
Table 15--Proposed Munitions for Other 780 Test Squadron Testing in the EGTTR
--------------------------------------------------------------------------------------------------------------------------------------------------------
Net explosive weight
Type Category (lb)/(kg) Detonation scenario Target type Annual quantity
--------------------------------------------------------------------------------------------------------------------------------------------------------
Live Munitions:
GBU-10, 24, or 31 (QUICKSINK)... Bomb................... 945 (428.5)........... Subsurface............ TBD................... 4 to 8
2,000 lb bomb with JDAM kit..... Bomb................... 945 (428.5) or less... HOB................... TBD................... 2
Inert GBU-39 (LSDB)............. Bomb................... 0.4 (0.2)............. HOB/Surface........... Small Boat............ 4
with live fuze..................
Inert GBU-53 (SDB II)........... Bomb................... 0.4 (0.2)............. HOB/Surface........... Small Boat............ 4
with live fuze..................
Inert Munitions:
SiAW AARGM-ER................... Missile................ N/A................... N/A................... TBD................... 7
Multipurpose Booster................ Booster................ N/A................... N/A................... TBD................... 1
JDAM ER......................... Bomb................... N/A................... N/A................... Water Surface and 3
Barge.
[[Page 8158]]
Navy HAAWC...................... Torpedo................ N/A................... N/A................... Water Surface......... 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
AARGM-ER = Advanced Anti-Radiation Guided Missile--Extended Range; EGTTR = Eglin Gulf Test and Training Range; Guided Bomb Unit; HOB = height of burst;
HAAWC = High Altitude Anti-Submarine Warfare Weapon Capability; JDAM = Joint Direct Attack Munition; lb = pound(s); LSDB = Laser Small-Diameter Bomb;
N/A = not applicable; SDB = Small-Diameter Bomb; SiAW = Stand-in Attack Weapon; TBD = to be determined.
The 96 OG proposes to continue expending approximately nine inert
bombs a year in the EGTTR for testing purposes. The bombs are expected
to be up to 2,000 lb (907 kg) in total weight. For the impact analysis,
the bombs to be used by the 96 OG in the EGTTR during the 2023-2030
mission period are assumed to be Mk-84 2,000 lb (907 kg) General
Purpose (GP) inert bombs (Table 16).
Table 16--Proposed Munitions for Inert Bomb Testing in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net explosive Detonation
Type Category weight (lb) scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Mk-84 (GP 2,000 lb) \a\......... Bomb.............. N/A N/A 9
----------------------------------------------------------------------------------------------------------------
\a\Assumed for impact analysis.
EGTTR = Eglin Gulf Test and Training Range; GP = General Purpose; lb = pound(s); Mk = Mark; N/A = not
applicable.
Naval School Explosive Ordnance Disposal (NAVSCOLEOD)
NAVSCOLEOD proposes to conduct training missions in the EGTTR which
would include Countermeasures (MCM) exercises to teach NAVSCOLEOD
students techniques for neutralizing mines underwater (Table 17).
Underwater MCM training exercises are conducted in nearshore waters and
primarily involve diving and placing small explosive charges adjacent
to inert mines by hand; the detonation of such charges disables live
mines. NAVSCOLEOD training is conducted offshore of Santa Rosa Island
and in other locations and has not yet extended into the EGTTR.
NAVSCOLEOD training proposed for the 2023-2030 mission period would
extend approximately 5 nmi (9.26 km) offshore of Santa Rosa Island, in
the EGTTR. Up to 8 MCM training missions would be conducted annually in
the EGTTR during the 2023-2030 period. Each mission would involve 4
underwater detonations of charges hand placed adjacent to inert mines,
for a total of 32 annual detonations. The MCM neutralization charges
consist of C-4 explosives, detonation cord, non-electric blasting caps,
time fuzes, and fuze igniters; each charge has a NEW of approximately
20 lb. (9.07 kg). During each mission, with a maximum of 4 charges,
would detonate with a delay no greater than 20 minutes between shots.
After the final detonation, or a delay greater than 20 minutes, a 30-
minute environmental observation would be conducted. Additionally,
NAVSCOLEOD proposes to conduct up to 80 floating mine training
missions, which would involve detonations of charges on the water
surface; these charges would have a NEW of approximately 5 lb (2.3 kg).
All NAVSCOLEOD missions would occur only during daylight hours.
Table 17--Proposed Munitions for NAVSCOLEOD Training in the EGTTR
----------------------------------------------------------------------------------------------------------------
Net Explosive
Type Category weight (lb)/(kg) Detonation scenario Annual quantity
----------------------------------------------------------------------------------------------------------------
Underwater Mine Charge.......... Charge............. \a\20 (9.1) Subsurface......... 32
Floating Mine Charge............ Charge............. \a\5 (2.3) Surface............ 80
----------------------------------------------------------------------------------------------------------------
\a\ Estimated
Description of Stressors
The USAF uses the EGTTR for training purposes and for testing of a
variety of weapon systems described in this proposed rule. All of the
weapons systems considered likely to cause the take of marine mammals
involve explosive detonations. Training and testing with these systems
may introduce acoustic (sound) energy or shock waves from explosives
into the environment. The following section describes explosives
detonated at or just below the surface of the water within the EGTTR.
Because of the complexity of analyzing sound propagation in the ocean
environment, the USAF relied on acoustic models in its environmental
analyses and rulemaking/LOA application that considered sound source
characteristics and conditions across the EGTTR.
Explosive detonations at the water surface send a shock wave and
sound energy through the water and can release gaseous by-products,
create an oscillating bubble, or cause a plume of water to shoot up
from the water surface. When an air-to-surface munition impacts the
water, some of the kinetic energy displaces water in the formation of
an impact ``crater'' in the water, some of the kinetic energy is
transmitted from the impact point as underwater acoustic energy in a
pressure impulse, and the remaining kinetic energy is retained by the
munition continuing to move through the water. Following impact, the
warhead of a live munition detonates at or slightly below the water
surface. The warhead detonation converts explosive
[[Page 8159]]
material into gas, further displacing water through the rapid creation
of a gas bubble in the water, and creates a much larger pressure wave
than the pressure wave created by the impact. These impulse pressure
waves radiate from the impact point at the speed of sound in water,
roughly 1,500 m per second. If the detonation is sufficiently deep, the
gas bubble goes through a series of expansions and contractions, with
each cycle being of successively lower energy. When detonations occur
below but near the water surface, the initial gas bubble reaches the
surface and causes venting, which also dissipates energy through the
ejection of water and release of detonation gases into the atmosphere.
When a detonation occurs below the water surface after the impact
crater has fully or partially closed, water can be violently ejected
upward by the pressure impulse and through venting of the gas bubble
formed by the detonation.
With radii of up to 15 m, the gas bubbles that would be generated
by EGTTR munition detonations would be larger than the depth of
detonation but much smaller than the water depth, so all munitions
analyzed are considered to fully vent to the surface without forming
underwater bubble expansion and contraction cycles. When detonations
occur at the water surface, a large portion of the energy and gases
that would otherwise form a detonation bubble are reflected upward from
the water. Likewise, when a shallow detonation occurs below the water
surface but prior to the impact crater closing, considerable energy is
reflected upward from the water. As a conservative assumption, no
energy losses from surface effects are included in the acoustic model.
The impulsive pressure waves generated by munition impact and
warhead detonation radiate spherically and are reflected between the
water surface and the sea bottom. There is generally some attenuation
of the pressure waves by the sea bottom but relatively little
attenuation of the pressure waves by the water surface. As a
conservative assumption, the water surface is assumed to be flat (no
waves) to allow for maximum reflectivity. Additionally, is it assumed
that all detonations occur in the water and none of the detonations
occur above the water surface when a munition impacts a target. This
conservative assumption implies that all munition energy is imparted to
the water rather than the intended targets. The potential impacts of
exposure to explosive detonations are discussed in detail in the
Potential Effects of Specified Activities on Marine Mammals and their
Habitat section.
Description of Marine Mammals in the Area of the Specified Activities
Table 18 lists all species or stocks for which take is expected and
proposed to be authorized for this activity, and summarizes information
related to the population or stock, including regulatory status under
the MMPA and Endangered Species Act (ESA) and potential biological
removal (PBR), where known. PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS'
SARs). While no serious injury or mortality is expected to occur, PBR
and annual serious injury and mortality from anthropogenic sources are
included here as gross indicators of the status of the species or
stocks and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All stocks managed under the MMPA in this region
are assessed in NMFS' 2021 U.S. Atlantic and Gulf of Mexico Marine
Mammal Stock Assessment (Hayes et al. 2022; <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>).
Table 18--Marine Mammals Potentially Present in the Specified Geographical Region
--------------------------------------------------------------------------------------------------------------------------------------------------------
NMFS stock abundance
ESA/MMPA status; (CV, Nmin, most recent Annual M/
Common name Scientific name Stock strategic (Y/N) abundance survey) \2\ PBR SI \3\
\1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals):
Rice's whale \4\................ Balaenoptera ricei..... Gulf of Mexico......... E/D; Y 51 (0.50; 34; 2017-18) 0.1 0.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Common bottlenose dolphin....... Tursiops 939runcates Northern GOM -; N 63,280 (0.11; 57,917; 556 65
truncatus. Continental Shelf. 2018).
Atlantic spotted dolphin........ Stenella frontalis..... GOM.................... -; N 21,506 (0.26; 17,339; 166 36
2017-18).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or designated as depleted under
the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or which is determined to be
declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is automatically designated
under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: <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' SARs, represent annual levels of human-caused mortality (M) plus serious injury (SI) from all sources combined (e.g.,
commercial fisheries, ship strike). These values are generally considered minimums because, among other reasons, not all fisheries that could interact
with a particular stock are observed and/or observer coverage is very low, and, for some stocks (such as the Atlantic spotted dolphin and continental
shelf stock of bottlenose dolphin), no estimate for injury due to the Deepwater Horizon oil spill has been included. See SARs for further discussion.
\4\ The 2021 final rule refers to the Gulf of Mexico (GOM) Bryde's whale (Balaenoptera edeni). These whales were subsequently described as a new
species, Rice's whale (Balaenoptera ricei) (Rosel et al., 2021).
[[Page 8160]]
As indicated above, all three species (with three managed stocks)
in Table 18 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. These species are
generally categorized into those species that occur over the
continental shelf, which is typically considered to extend from shore
to the 200-m (656-ft) isobath, and those species that occur beyond the
continental shelf break in waters deeper than 200 m. Since water depths
range from approximately 30 to 145 m in the existing LIA and from
approximately 35 to 95 m in the proposed new East LIA, most of EGTTR
activities would occur in waters over the continental shelf. Any live
munitions would be set to detonate above the water surface if used
outside the LIA beyond the 200-m isobath. Airburst detonations are not
considered to affect marine mammals because there is little
transmission of pressure or sound energy across the air-water
interface. For these reasons, only cetacean species that predominantly
occur landward of the 200-m isobath are carried forward in the
analysis. These species include common bottlenose dolphin, Atlantic
spotted dolphin, and Rice's whale.
Common Bottlenose Dolphin
The common bottlenose dolphin is abundant in the northeastern Gulf
from inshore to upper continental slope waters less than 1,000 m deep
(Mullin and Fulling 2004). It is the most common cetacean species found
in the coastal waters of the Gulf of Mexico. Genetically distinct
coastal and offshore ecotypes of the bottlenose dolphin occur in the
Gulf of Mexico and in other locations (Hoelzel et al. 1998). A total of
36 common bottlenose dolphin stocks have been identified in the
northern Gulf of Mexico including coastal, continental shelf, and
oceanic stocks, as well as 31 bay, sound, and estuarine stocks (Waring
et al. 2016). Stocks that may be found near or within the EGTTR include
the Gulf of Mexico Northern Coastal, Northern Gulf of Mexico
Continental Shelf, and Northern Gulf of Mexico Oceanic stocks, in
addition to three inshore stocks, which include the Choctawhatchee Bay,
Pensacola/East Bay, and St. Andrew Bay stocks. However, the designated
inshore stock areas are landward of the EGTTR boundary; therefore,
individuals from these stocks are not anticipated to be exposed to or
affected by EGTTR operations. The Gulf of Mexico Northern Coastal Stock
inhabits waters from shore to the 20-m (65-ft) isobath and, therefore,
has potential to occur within the EGTTR, which starts at 3 nmi (5.5 km)
offshore, where water depths can be 20 m or slightly less. However,
given that most EGTTR operations would occur in either the existing
LIA, where water depths range from approximately 30 to 145 m, or in the
proposed East LIA, where water depths range from approximately 35 to 85
m, EGTTR operations are expected to have no appreciable effect on this
stock. The Northern Gulf of Mexico Continental Shelf Stock inhabits
waters that are 20 to 200 m deep and, therefore, is expected to be the
primary bottlenose dolphin stock that occurs in the existing LIA. The
Northern Gulf of Mexico Oceanic Stock inhabits waters deeper than 200 m
and, therefore, is not expected to be exposed to or affected by EGGTR
operations in either LIA.
The bottlenose dolphin reaches a length ranging from about 6 to 13
ft (1.8 to 3.9 m) and a weight ranging from about 300 to 1,400 lb (136
to 635 kg). The diet of bottlenose dolphins consists primarily of fish,
squid, and crustaceans. They hunt for prey using a variety of
techniques individually and cooperatively. For example, they may work
as a group to herd and trap fish as well as use high-frequency
echolocation, to catch prey.
Atlantic Spotted Dolphin
The Atlantic spotted dolphin occurs throughout the Atlantic Ocean
and the Gulf of Mexico. There is a single stock of the Atlantic spotted
dolphin in U.S. Gulf waters, which is the Northern Gulf of Mexico
Stock. Animals occur primarily from continental shelf waters of 10-200
m deep to slope waters <500 m deep and were spotted in all seasons
during aerial and vessel surveys of the northern Gulf of Mexico (i.e.,
U.S. Gulf of Mexico; Hansen et al. 1996; Mullin and Hoggard 2000;
Fulling et al. 2003; Mullin and Fulling 2004; Maze-Foley and Mullin
2006). Atlantic spotted dolphins are about 5 to 7.5 ft (1.5 to 2.3 m)
long and weigh about 220 to 315 lb (99.8 to 142.8 kg). Their diet
consists primarily of small fish, invertebrates, and cephalopods, which
they catch using a variety of techniques including echolocation.
Atlantic spotted dolphins are social animals and form groups of up to
200 individuals. Most groups consist of fewer than 50 individuals, and
in coastal waters groups typically consist of 5 to 15 individuals (NMFS
2021b).
Rice's Whale
The Gulf of Mexico Bryde's whale was listed as endangered
throughout its entire range on April 15, 2019, under the Endangered
Species Act (ESA). Based on genetic analyses and new morphological
information NOAA Fisheries recently revised the common and scientific
names to recognize this new species (Balaenoptera ricei) as being
separate from other Bryde's whale populations (86 FR 47022; August 21,
2021). Rosel and Wilcox (2014) first identified a new, evolutionarily
distinct lineage of whale in the Gulf of Mexico. Genetic analysis of
whales sampled in the northeastern Gulf of Mexico revealed that this
population is evolutionarily distinct from all other whales within the
Bryde's whale complex and all other known balaenopterid species (Rosel
and Wilcox 2014).
The Rice's whale is the only year-round resident baleen whale
species in the Gulf of Mexico. Rosel et.al. (2021) reported that based
on a compilation of sighting and stranding data from 1992 to 2019, the
primary habitat of the Rice's whale is the northeastern Gulf of Mexico,
particularly the De Soto Canyon area, at water depths of 150 to 410 m.
Biologically Important Areas (BIAs) include areas of known
importance for reproduction, feeding, or migration, or areas where
small and resident populations are known to occur (Van Parijs, 2015).
Unlike ESA critical habitat, these areas are not formally designated
pursuant to any statute or law but are a compilation of the best
available science intended to inform impact and mitigation analyses. In
2015, a year round small and resident population BIA for Bryde's whales
(later designated as Rice's whales) was identified from the De Soto
Canyon along the shelf break to the southeast (LaBrecque et al. 2015).
The 23,559 km\2\ BIA covers waters between 100 and 300 m deep from
approximately south of Pensacola to approximately west of Fort Myers,
FL (LaBrecque et al. 2015). The deepest location where a Rice's whale
has been sighted is 408 m (Rosel et al. 2021). Habitat for the Rice's
whale is currently considered by NMFS to be primarily within the depth
range of 100 to 400 m in this part of the Gulf of Mexico (NMFS 2016,
2020a), and in 2019 NMFS delineated a Core Distribution Area (<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.
The Rice's whale is a medium-sized baleen whale. To date, the
largest verified Rice's whale to strand was a lactating female about
12.65 m long; the largest male was 11.26 m (Rosel et al. 2021). Little
is known about their
[[Page 8161]]
foraging ecology and diet. However, data from two Rice's whales suggest
they may mostly forage at or near the seafloor.
Unusual Mortality Events (UMEs)
An UME is defined under Section 410(6) of the MMPA as a stranding
that is unexpected; it involves a significant die-off of any marine
mammal population and demands immediate response. There are currently
no UMEs with ongoing investigations in the EGTTR. There was a UME for
bottlenose dolphins that was active beginning in February 2019 and
closing in November of the same year that included the northern Gulf of
Mexico. Dolphins developed lesions that were thought to be caused by
exposure to low salinity water stemming from extreme freshwater
discharge. This UME is closed.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al.
(2007, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). Note that no direct measurements of
hearing ability have been successfully completed for mysticetes (i.e.,
low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 19.
Table 19--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans......... 7 Hz to 35 kHz.
(baleen whales)......................
Mid-frequency (MF) cetaceans......... 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans........ 275 Hz to 160 kHz.
(true porpoises, Kogia, river
dolphins, Cephalorhynchid,
Lagenorhynchus cruciger & L.
australis).
Phocid pinnipeds (PW) (underwater)... 50 Hz to 86 kHz.
(true seals).........................
Otariid pinnipeds (OW) (underwater).. 60 Hz to 39 kHz.
(sea lions and fur seals)............
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al. 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary of the ways that components of the
specified activity may impact marine mammals and their habitat. The
Estimated Take of Marine Mammals section later in this rule includes a
quantitative analysis of the number of instances of take that could
occur from these activities. The Preliminary Analysis and Negligible
Impact Determination section considers the content of this section, the
Estimated Take of Marine Mammals section, and the Proposed Mitigation
Measures section to draw conclusions regarding the likely impacts of
these activities on the reproductive success or survivorship of
individuals and whether those impacts on individuals are likely to
adversely affect the species through effects on annual rates of
recruitment or survival.
The USAF has requested authorization for the take of marine mammals
that may occur incidental to training and testing activities in the
EGTTR. The USAF analyzed potential impacts to marine mammals from air-
to-surface operations that involve firing live or inert munitions,
including missiles, bombs, and gun ammunition, from aircraft at targets
on the water surface in the LOA application as well as the 2022 REA,
for which NMFS served as a cooperating agency. The proposed training
and testing exercises have the potential to cause take of marine
mammals by exposing them to impulsive noise and pressure waves
generated by explosive detonation at or near the surface of the water.
Exposure to noise or pressure resulting from these detonations could
result in non-lethal injury (Level A harassment) or disturbance (Level
B harassment). As explained in the Estimated Take of Marine Mammals
section, neither mortality nor non-auditory injury are anticipated or
authorized.
A summary of the potential impacts of the pressure waves generated
by explosive detonations is included below. Following, a brief
technical background is provided here on sound, on the characteristics
of certain sound types, and on metrics used in this proposal. Last, a
brief overview of the potential effects (e.g., tolerance, masking,
hearing threshold shift, behavioral disturbance, and stress responses)
to marine mammals associated with the USAF's proposed activities is
included.
[[Page 8162]]
Impacts from Pressure Waves Caused by Explosive Detonations
Exposure to the pressure waves generated by explosive detonations
has the potential to cause injury, serious injury, or mortality,
although those impacts are not anticipated here. (This conclusion is
based on the size, type, depth, and duration of the explosives in
combination with the density of marine mammals, which together predict
a low probability of exposures, as well as the required mitigation
measures, as described in detail the Estimated Take of Marine Mammals
section.) The potential acoustic impacts of explosive detonations
(e.g., permanent threshold shift (PTS), temporary threshold shift
(TTS), and behavioral disturbance) are described in subsequent
sections.
Generally speaking, the pressure from munition detonations have the
potential to cause mortality, injury, hearing impairment, or behavioral
disturbances in marine mammals, depending on the explosive energy
released by the munition and the distance of the animal from the
detonation. The impulsive noise from these detonations may also cause
hearing impairment or behavioral disturbances. The most potentially
severe effects would occur close to the detonation point, including
tissue damage, barotrauma, or even death. Serious injury or mortality
to marine mammals from explosive detonations, if they occurred, which
is not expected here, would consist of primary blast injury, which
refers to those injuries that result from the compression of a body
exposed to a blast wave and which is usually observed as barotrauma of
gas-containing structures (e.g., lung and gut) and structural damage to
the auditory system (Richmond et al. 1973). The near instantaneous high
magnitude pressure change near an explosion can injure an animal where
tissue material properties significantly differ from the surrounding
environment, such as around air-filled cavities in the lungs or
gastrointestinal (GI) tract. The gas-containing organs (lungs and GI
tract) are most vulnerable to primary blast injury. Severe injuries to
these organs are presumed to result in mortality (e.g., severe lung
damage may introduce air into the cardiopulmonary vascular system,
resulting in lethal air emboli). Large pressure changes at tissue-air
interfaces in the lungs and GI tract may cause tissue rupture,
resulting in a range of injuries depending on degree of exposure.
Recoverable injuries would include slight lung injury, such as
capillary interstitial bleeding, and contusions to the GI tract. More
severe injuries, such as tissue lacerations, major hemorrhage, organ
rupture, or air in the chest cavity (pneumothorax), would significantly
reduce fitness and likely cause death in the wild. Rupture of the lung
may also introduce air into the vascular system, producing air emboli
that can cause a stroke or heart attack and restrict oxygen delivery to
critical organs. Susceptibility would increase with depth, until normal
lung collapse (due to increasing hydrostatic pressure) and increasing
ambient pressures again reduce susceptibility.
Exposures to higher levels of impulse and pressure levels would
generally result in greater impacts to an individual animal. However,
the effects of noise on marine mammals are highly variable, often
depending on species and contextual factors (Richardson et al. 1995).
As described in the Estimated Take of Marine Mammals section, the more
serious impacts (i.e., mortality, serious injury, and non-auditory
injury) are not anticipated to result from this action.
The USAF performed a quantitative analysis to estimate the
probability that marine mammals could be exposed to the sound and
energy from explosions during USAF activities and the effects of those
exposures (Appendix A in LOA Application). The effects of underwater
explosions on marine mammals depend on a variety of factors including
animal size and depth; charge size and depth; depth of the water
column; and distance between the animal and the charge. In general, an
animal would be less susceptible to injury near the water surface
because the pressure wave reflected from the water surface would
interfere with the direct path pressure wave, reducing positive
pressure exposure. There are a limited number of explosives that would
detonate just below the water surface as outlined previously in the
section, Description of Stressors. Most explosives would detonate at or
near the surface of the water and are unlikely to transfer energy
underwater sufficient to result in non-auditory injury (GI injury or
lung injury) or mortality. For reasons described in the Estimated Take
of Marine Mammals section, NMFS agrees with USAF's analysis that no
mortality or serious injury from tissue damage in the form of GI injury
or lung injury is anticipated to result from the proposed activities.
The USAF did not request, and NMFS does not propose, mortality or
serious injury for authorization, and therefore this proposed rule will
not discuss it further. For additional details on the criteria for
estimating non-auditory physiological impacts on marine mammals due to
naval underwater explosions, we refer the reader to the report,
Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects
Analysis (Phase III) (U.S. Department of the Navy, 2017e).
Sections 6, 7, and 9 of the USAF's application include summaries of
the ways that components of the specified activity may impact marine
mammals and their habitat, including specific discussion of potential
effects to marine mammals from noise and pressure waves produced
through the use explosives detonating at or near the surface. We have
reviewed the USAF's discussion of potential effects for accuracy and
completeness in its application and refer to that information rather
than repeating it in full here. Below we include a summary of the
potential effects to marine mammals.
Description of Sound Sources
This section contains a brief technical background on sound, on the
characteristics of certain sound types, and on metrics used in this
proposal inasmuch as the information is relevant to the specified
activity and to a discussion of the potential effects of the specified
activity on marine mammals found later in this document. For general
information on sound and its interaction with the marine environment,
please see Au and Hastings (2008); Richardson et al. (1995); and Urick
(1983).
Sound travels in waves, the basic components of which are
frequency, wavelength, velocity, and amplitude. Frequency is the number
of pressure waves that pass by a reference point per unit of time and
is measured in hertz or cycles per second. Wavelength is the distance
between two peaks or corresponding points of a sound wave (length of
one cycle). Higher frequency sounds have shorter wavelengths than lower
frequency sounds, and typically attenuate (decrease) more rapidly,
except in certain cases in shallower water. Amplitude is the height of
the sound pressure wave or the ``loudness'' of a sound and is typically
described using the relative unit of the decibel (dB). A sound pressure
level (SPL) in dB is described as the ratio between a measured pressure
and a reference pressure (for underwater sound, this is 1 microPascal
([mu]Pa)), and is a logarithmic unit that accounts for large variations
in amplitude. Therefore, a relatively small change in dB corresponds to
large changes in sound pressure. The source level (SL) represents the
SPL referenced at a distance of 1 m from the source (referenced to 1
[mu]Pa), while the received level is the SPL at the listener's position
(referenced to 1 [mu]Pa).
[[Page 8163]]
Root mean square (rms) is the quadratic mean sound pressure over
the duration of an impulse. Root mean square is calculated by squaring
all of the sound amplitudes, averaging the squares, and then taking the
square root of the average (Urick 1983). Root mean square accounts for
both positive and negative values; squaring the pressures makes all
values positive so that they may be accounted for in the summation of
pressure levels (Hastings and Popper 2005). This measurement is often
used in the context of discussing behavioral effects, in part because
behavioral effects, which often result from auditory cues, may be
better expressed through averaged units than by peak pressures.
Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s)
represents the total energy in a stated frequency band over a stated
time interval or event and considers both intensity and duration of
exposure. The per-pulse SEL is calculated over the time window
containing the entire pulse (i.e., 100 percent of the acoustic energy).
SEL is a cumulative metric; it can be accumulated over a single pulse,
or calculated over periods containing multiple pulses. Cumulative SEL
represents the total energy accumulated by a receiver over a defined
time window or during an event. Peak sound pressure (also referred to
as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous
sound pressure measurable in the water at a specified distance from the
source and is represented in the same units as the rms sound pressure.
When underwater objects vibrate or activity occurs, sound-pressure
waves are created. These waves alternately compress and decompress the
water as the sound wave travels. Underwater sound waves radiate in a
manner similar to ripples on the surface of a pond and may be either
directed in a beam or beams or may radiate in all directions
(omnidirectional sources). The compressions and decompressions
associated with sound waves are detected as changes in pressure by
aquatic life and man-made sound receptors such as hydrophones.
Even in the absence of sound from the specified activity, the
underwater environment is typically loud due to ambient sound, which is
defined as environmental background sound levels lacking a single
source or point (Richardson et al. 1995). The sound level of a region
is defined by the total acoustical energy being generated by known and
unknown sources. These sources may include physical (e.g., wind and
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds
produced by marine mammals, fish, and invertebrates), and anthropogenic
(e.g., vessels, dredging, construction) sound. A number of sources
contribute to ambient sound, including wind and waves, which are a main
source of naturally occurring ambient sound for frequencies between 200
Hz and 50 kHz (Mitson 1995). In general, ambient sound levels tend to
increase with increasing wind speed and wave height. Precipitation can
become an important component of total sound at frequencies above 500
Hz, and possibly down to 100 Hz during quiet times. Marine mammals can
contribute significantly to ambient sound levels, as can some fish and
snapping shrimp. The frequency band for biological contributions is
from approximately 12 Hz to over 100 kHz. Sources of ambient sound
related to human activity include transportation (surface vessels),
dredging and construction, oil and gas drilling and production,
geophysical surveys, sonar, and explosions. Vessel noise typically
dominates the total ambient sound for frequencies between 20 and 300
Hz. In general, the frequencies of anthropogenic sounds are below 1 kHz
and, if higher frequency sound levels are created, they attenuate
rapidly.
The sum of the various natural and anthropogenic sound sources that
comprise ambient sound at any given location and time depends not only
on the source levels (as determined by current weather conditions and
levels of biological and human activity) but also on the ability of
sound to propagate through the environment. In turn, sound propagation
is dependent on the spatially and temporally varying properties of the
water column and sea floor, and is frequency-dependent. As a result of
the dependence on a large number of varying factors, ambient sound
levels can be expected to vary widely over both coarse and fine spatial
and temporal scales. Sound levels at a given frequency and location can
vary by 10-20 decibels (dB) from day to day (Richardson et al. 1995).
The result is that, depending on the source type and its intensity,
sound from the specified activity may be a negligible addition to the
local environment or could form a distinctive signal that may affect
marine mammals. Details of source types are described in the following
text.
Sounds are often considered to fall into one of two general types:
Pulsed and non-pulsed (defined in the following). The distinction
between these two sound types is important because they have differing
potential to cause physical effects, particularly with regard to
hearing (e.g., Ward 1997 in Southall et al. 2007). Please see Southall
et al. (2007) and NMFS' Technical Guidance for Assessing the Effects of
Anthropogenic Sound on Marine Mammal Hearing (Version 2.0) Underwater
Thresholds for Onset of Permanent and Temporary Threshold Shift
(Acoustic Technical Guidance) (NMFS 2018) for an in-depth discussion of
these concepts. The distinction between these two sound types is not
always obvious, as certain signals share properties of both pulsed and
non-pulsed sounds. A signal near a source could be categorized as a
pulse, but due to propagation effects as it moves farther from the
source, the signal duration becomes longer (e.g., Greene and Richardson
1988).
Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic
booms, impact pile driving) produce signals that are brief (typically
considered to be less than one second), broadband, atonal transients
(ANSI 1986, 2005; Harris 1998; NIOSH 1998; ISO 2003) and occur either
as isolated events or repeated in some succession. Pulsed sounds are
all characterized by a relatively rapid rise from ambient pressure to a
maximal pressure value followed by a rapid decay period that may
include a period of diminishing, oscillating maximal and minimal
pressures, and generally have an increased capacity to induce physical
injury as compared with sounds that lack these features.
Non-pulsed sounds can be tonal, narrowband or broadband, brief or
prolonged, and may be either continuous or intermittent (ANSI, 1995;
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals
of short duration but without the essential properties of pulses (e.g.,
rapid rise time). Examples of non-pulsed sounds include those produced
by vessels, aircraft, machinery operations such as drilling or
dredging, vibratory pile driving, and active sonar systems. The
duration of such sounds, as received at a distance, can be greatly
extended in a highly reverberant environment.
Hearing Loss--Threshold Shift
Marine mammals exposed to high-intensity sound, or to lower-
intensity sound for prolonged periods, can experience hearing threshold
shift, which is the loss of hearing sensitivity at certain frequency
ranges after cessation of sound (Finneran 2015). Threshold shift can be
permanent (PTS), in which case the loss of hearing sensitivity is not
fully recoverable, or temporary (TTS), in which case the animal's
hearing threshold would recover over time (Southall et al. 2007).
[[Page 8164]]
Irreparable damage to the inner or outer cochlear hair cells may cause
PTS; however, other mechanisms are also involved, such as exceeding the
elastic limits of certain tissues and membranes in the middle and inner
ears and resultant changes in the chemical composition of the inner ear
fluids (Southall et al. 2007). PTS is considered an injury and Level A
harassment while TTS is considered to be Level B harassment and not
considered an injury.
Hearing loss, or threshold shift (TS), is typically quantified in
terms of the amount (in decibels) that hearing thresholds at one or
more specified frequencies are elevated, compared to their pre-exposure
values, at some specific time after the noise exposure. The amount of
TS measured usually decreases with increasing recovery time--the amount
of time that has elapsed since a noise exposure. If the TS eventually
returns to zero (i.e., the hearing threshold returns to the pre-
exposure value), the threshold shift is called a TTS. If the TS does
not completely recover (the threshold remains elevated compared to the
pre-exposure value), the remaining TS is a PTS.
Hearing loss has only been studied in a few species of marine
mammals, although hearing studies with terrestrial mammals are also
informative. There are no direct measurements of hearing loss in marine
mammals due to exposure to explosive sources. The sound resulting from
an explosive detonation is considered an impulsive sound and shares
important qualities (i.e., short duration and fast rise time) with
other impulsive sounds such as those produced by air guns. General
research findings regarding TTS and PTS in marine mammals, as well as
findings specific to exposure to other impulsive sound sources, are
discussed below.
Many studies have examined noise-induced hearing loss in marine
mammals (see Finneran (2015) and Southall et al. (2019) for summaries),
however for cetaceans, published data on the onset of TTS are limited
to the captive bottlenose dolphin, beluga, harbor porpoise, and Yangtze
finless porpoise, and, for pinnipeds in water, measurements of TTS are
limited to harbor seals, elephant seals, and California sea lions.
These studies examine hearing thresholds measured in marine mammals
before and after exposure to intense sounds. The difference between the
pre-exposure and post-exposure thresholds can then be used to determine
the amount of threshold shift at various post-exposure times. NMFS has
reviewed the available studies, which are summarized below:
<bullet> The method used to test hearing may affect the resulting
amount of measured TTS, with neurophysiological measures producing
larger amounts of TTS compared to psychophysical measures (Finneran et
al. 2007; Finneran 2015).
<bullet> The amount of TTS varies with the hearing test frequency.
As the exposure SPL increases, the frequency at which the maximum TTS
occurs also increases (Kastelein et al. 2014). For high-level
exposures, the maximum TTS typically occurs one-half to one octave
above the exposure frequency (Finneran et al. 2007; Mooney et al.
2009a; Nachtigall et al. 2004; Popov et al. 2011; Popov et al. 2013;
Schlundt et al. 2000; Kastelein et al. 2021b; Kastelein et al. 2022).
The overall spread of TTS from tonal exposures can therefore extend
over a large frequency range (i.e., narrowband exposures can produce
broadband (greater than one octave) TTS).
<bullet> The amount of TTS increases with exposure SPL and duration
and is correlated with SEL, especially if the range of exposure
durations is relatively small (Kastak et al. 2007; Kastelein et al.
2014b; Popov et al. 2014). As the exposure duration increases, however,
the relationship between TTS and SEL begins to break down.
Specifically, duration has a more significant effect on TTS than would
be predicted on the basis of SEL alone (Finneran et al. 2010a; Kastak
et al. 2005; Mooney et al. 2009a). This means if two exposures have the
same SEL but different durations, the exposure with the longer duration
(thus lower SPL) will tend to produce more TTS than the exposure with
the higher SPL and shorter duration. In most acoustic impact
assessments, the scenarios of interest involve shorter duration
exposures than the marine mammal experimental data from which impact
thresholds are derived; therefore, use of SEL tends to over-estimate
the amount of TTS. Despite this, SEL continues to be used in many
situations because it is relatively simple, more accurate than SPL
alone, and lends itself easily to scenarios involving multiple
exposures with different SPL.
<bullet> Gradual increases of TTS may not be directly observable
with increasing exposure levels before the onset of PTS (Reichmuth et
al. 2019). Similarly, PTS can occur without measurable behavioral
modifications (Reichmuth et al. 2019).
<bullet> The amount of TTS depends on the exposure frequency.
Sounds at low frequencies, well below the region of best sensitivity,
are less hazardous than those at higher frequencies, near the region of
best sensitivity (Finneran and Schlundt, 2013). The onset of TTS--
defined as the exposure level necessary to produce 6 dB of TTS (i.e.,
clearly above the typical variation in threshold measurements)--also
varies with exposure frequency. At low frequencies, onset-TTS exposure
levels are higher compared to those in the region of best sensitivity.
For example, for harbor porpoises exposed to one-sixth octave noise
bands at 16 kHz (Kastelein et al. 2019a), 32 kHz (Kastelein et al.
2019b), 63 kHz (Kastelein et al. 2020a), and 88.4 kHz (Kastelein et al.
2020b), less susceptibility to TTS was found as frequency increased,
whereas exposure frequencies below ~6.5 kHz showed an increase in TTS
susceptibility as frequency increased and approached the region of best
sensitivity. Kastelein et al. (2020b) showed a much higher onset of TTS
for a 88.5 kHz exposure as compared to lower exposure frequencies
(i.e., 16 kHz (Kastelein et al., 2019) 1.5 kHz and 6.5 kHz (Kastelein
et al. 2020a)). For the 88.4 kHz test frequency, a 185 dB re 1
micropascal squared per second ([micro]Pa\2\ -s) exposure resulted in
3.6 dB of TTS, and a 191 dB re 1 [micro]Pa\2\ -s exposure produced 5.2
dB of TTS at 100 kHz and 5.4 dB of TTS at 125 kHz. Together, these new
studies demonstrate that the criteria for high-frequency (HF) cetacean
auditory impacts is likely to be conservative.
<bullet> TTS can accumulate across multiple exposures, but the
resulting TTS will be less than the TTS from a single, continuous
exposure with the same SEL (Finneran et al. 2010a; Kastelein et al.
2014b; Kastelein et al. 2015b; Mooney et al. 2009b). This means that
TTS predictions based on the total, cumulative SEL will overestimate
the amount of TTS from intermittent exposures such as sonars and
impulsive sources. The importance of duty cycle in predicting the
likelihood of TTS is demonstrated further in Kastelein et al. (2021b).
The authors found that reducing the duty cycle of a sound generally
reduced the potential for TTS in California sea lions, and that,
further, California sea lions are more susceptible to TTS than
previously believed at the 2 and 4 kHz frequencies tested.
<bullet> The amount of observed TTS tends to decrease with
increasing time following the exposure; however, the relationship is
not monotonic (i.e., increasing exposure does not always increase TTS).
The time required for complete recovery of hearing depends on the
magnitude of the initial shift; for relatively small shifts recovery
may be complete in a few minutes, while large
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shifts (e.g., approximately 40 dB) may require several days for
recovery. Recovery times are consistent for similar-magnitude TTS,
regardless of the type of fatiguing sound exposure (impulsive,
continuous noise band, or sinusoidal wave; (Kastelein et al. 2019c)).
Under many circumstances TTS recovers linearly with the logarithm of
time (Finneran et al., 2010a, 2010b; Finneran and Schlundt 2013;
Kastelein et al. 2012a; Kastelein et al. 2012b; Kastelein et al. 2014b;
Kastelein et al. 2014c; Popov et al. 2011; Popov et al. 2013; Popov et
al. 2014). This means that for each doubling of recovery time, the
amount of TTS will decrease by the same amount (e.g., 6 dB recovery per
doubling of time).
Nachtigall et al. (2018) and Finneran (2018) describe the
measurements of hearing sensitivity of multiple odontocete species
(bottlenose dolphin, harbor porpoise, beluga, and false killer whale)
when a relatively loud sound was preceded by a warning sound. These
captive animals were shown to reduce hearing sensitivity when warned of
an impending intense sound. Based on these experimental observations of
captive animals, the authors suggest that wild animals may dampen their
hearing during prolonged exposures or if conditioned to anticipate
intense sounds. Another study showed that echolocating animals
(including odontocetes) might have anatomical specializations that
might allow for conditioned hearing reduction and filtering of low-
frequency ambient noise, including increased stiffness and control of
middle ear structures and placement of inner ear structures (Ketten et
al. 2021). Finneran recommends further investigation of the mechanisms
of hearing sensitivity reduction in order to understand the
implications for interpretation of existing TTS data obtained from
captive animals, notably for considering TTS due to short duration,
unpredictable exposures.
Marine mammal TTS data from impulsive sources are limited. Two
studies with measured TTS of 6 dB or more, with Finneran et al. (2002)
reporting behaviorally measured TTSs of 6 and 7 dB in a beluga exposed
to single impulses from a seismic water gun, and with Lucke et al.
(2009) reporting Audio-evoked Potential measured TTS of 7-20 dB in a
harbor porpoise exposed to single impulses from a seismic air gun.
Kastelein et al. (2017) quantified TTS caused by exposure to 10-20
consecutive shots from 2 airguns simultaneously in harbor porpoises.
Statistically significant initial TTS (1-4 min after sound exposure
stopped) of ~4.4 dB occurred. However, recovery occurred within 12 min
post-exposure.
Several impulsive noise exposure studies have also been conducted
without behaviorally measurable TTS. Specifically, Finneran et al.
(2000) exposed dolphins and belugas to single impulses from an
explosion simulator, and Finneran et al. (2015) exposed three dolphins
to sequences of 10 impulses from a seismic air gun (maximum cumulative
SEL = 193-195 dB re 1 [mu]Pa\2\s, peak SPL =196-210 dB re 1 [mu]Pa)
without measurable TTS. The proposed activities include both TTS and a
limited amount of PTS in some marine mammals.
Behavioral Disturbance
Behavioral responses to sound are highly variable and context-
specific. Many different variables can influence an animal's perception
of and response to an acoustic event. An animal's prior experience with
a sound or sound source affects whether it is less likely (habituation)
or more likely (sensitization) to respond to certain sounds in the
future (animals can also be innately predisposed to respond to certain
sounds in certain ways) (Southall et al. 2007). Related to the sound
itself, the perceived nearness of the sound, bearing of the sound
(approaching vs. retreating), the similarity of a sound to biologically
relevant sounds in the animal's environment (i.e., calls of predators,
prey, or conspecifics), and familiarity of the sound may affect the way
an animal responds to the sound (Southall et al.2007, DeRuiter et al.
2013). Individuals (of different age, gender, reproductive status,
etc.) among most populations will have variable hearing capabilities,
and differing behavioral sensitivities to sounds that will be affected
by prior conditioning, experience, and current activities of those
individuals. Often, specific acoustic features of the sound and
contextual variables (i.e., proximity, duration, or recurrence of the
sound or the current behavior that the marine mammal is engaged in or
its prior experience), as well as entirely separate factors such as the
physical presence of a nearby vessel, may be more relevant to the
animal's response than the received level alone.
Controlled experiments with captive marine mammals have shown
pronounced behavioral reactions, including avoidance of loud underwater
sound sources (Ridgway et al. 1997; Finneran et al. 2003). Observed
responses of wild marine mammals to loud pulsed sound sources
(typically seismic guns or acoustic harassment devices) have been
varied but often consist of avoidance behavior or other behavioral
changes suggesting discomfort (Morton and Symonds 2002; Thorson and
Reyff 2006; see also Gordon et al., 2004; Nowacek et al. 2007).
The onset of noise can result in temporary, short-term changes in
an animal's typical behavior and/or avoidance of the affected area.
These behavioral changes may include: reduced/increased vocal
activities; changing/cessation of certain behavioral activities (such
as socializing or feeding); visible startle response or aggressive
behavior; avoidance of areas where sound sources are located; and/or
flight responses (Richardson et al. 1995).
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, the consequences of behavioral
modification could potentially be biologically significant if the
change affects growth, survival, or reproduction. The onset of
behavioral disturbance from anthropogenic sound depends on both
external factors (characteristics of sound sources and their paths) and
the specific characteristics of the receiving animals (hearing,
motivation, experience, demography) and is difficult to predict
(Southall et al. 2007).
Ellison et al. (2011) outlined an approach to assessing the effects
of sound on marine mammals that incorporates contextual-based factors.
The authors recommend considering not just the received level of sound,
but also the activity the animal is engaged in at the time the sound is
received, the nature and novelty of the sound (i.e., is this a new
sound from the animal's perspective), and the distance between the
sound source and the animal. They submit that this ``exposure
context,'' as described, greatly influences the type of behavioral
response exhibited by the animal. Forney et al. (2017) also point out
that an apparent lack of response (e.g., no displacement or avoidance
of a sound source) may not necessarily mean there is no cost to the
individual or population, as some resources or habitats may be of such
high value that animals may choose to stay, even when experiencing
stress or hearing loss. Forney et al. (2017) recommend considering both
the costs of remaining in an area of noise exposure such as TTS, PTS,
or masking, which could lead to an increased risk of predation or other
threats or a decreased capability to forage, and the costs of
displacement,
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including potential increased risk of vessel strike, increased risks of
predation or competition for resources, or decreased habitat suitable
for foraging, resting, or socializing. This sort of contextual
information is challenging to predict with accuracy for ongoing
activities that occur over large spatial and temporal expanses.
However, distance is one contextual factor for which data exist to
quantitatively inform a take estimate, and the method for predicting
Level B harassment in this proposed rule does consider distance to the
source. Other factors are often considered qualitatively in the
analysis of the likely consequences of sound exposure, where supporting
information is available.
Exposure of marine mammals to sound sources can result in, but is
not limited to, no response or any of the following observable
responses: increased alertness; orientation or attraction to a sound
source; vocal modifications; cessation of feeding; cessation of social
interaction; alteration of movement or diving behavior; habitat
abandonment (temporary or permanent); and, in severe cases, panic,
flight, stampede, or stranding, potentially resulting in death
(Southall et al. 2007). A review of marine mammal responses to
anthropogenic sound was first conducted by Richardson (1995). More
recent reviews (Nowacek et al. 2007; DeRuiter et al. 2012 and 2013;
Ellison et al. 2012; Gomez et al. 2016) address studies conducted since
1995 and focused on observations where the received sound level of the
exposed marine mammal(s) was known or could be estimated. Gomez et al.
(2016) conducted a review of the literature considering the contextual
information of exposure in addition to received level and found that
higher received levels were not always associated with more severe
behavioral responses and vice versa. Southall et al. (2016) states that
results demonstrate that some individuals of different species display
clear yet varied responses, some of which have negative implications,
while others appear to tolerate high levels, and that responses may not
be fully predictable with simple acoustic exposure metrics (e.g.,
received sound level). Rather, the authors state that differences among
species and individuals along with contextual aspects of exposure
(e.g., behavioral state) appear to affect response probability.
During an activity with a series of explosions (not concurrent
multiple explosions shown in a burst), an animal is expected to exhibit
a startle reaction to the sound of the first detonation followed by
another behavioral response after multiple detonations. At close ranges
and high sound levels, avoidance of the area around the explosions is
the assumed behavioral response in most cases. In certain
circumstances, exposure to loud sounds can interrupt feeding behaviors
and potentially decrease foraging success, interfere with communication
or migration, or disrupt important reproductive or young-rearing
behaviors, among other effects.
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing, on a diel cycle (24-hour cycle). Behavioral
reactions to noise exposure (such as disruption of critical life
functions, displacement, or avoidance of important habitat) are more
likely to be significant for fitness if they last more than one diel
cycle or recur on subsequent days (Southall et al. 2007). Consequently,
a behavioral response lasting less than one day and not recurring on
subsequent days is not considered particularly severe unless it could
directly affect reproduction or survival (Southall et al. 2007). It is
important to note the difference between behavioral reactions lasting
or recurring over multiple days and anthropogenic activities lasting or
recurring over multiple days. For example, just because a given
anthropogenic activity lasts for multiple days (e.g., a training event)
does not necessarily mean that individual animals will be either
exposed to those activity-related stressors (i.e., explosions) for
multiple days or further exposed at a level would result in sustained
multi-day substantive behavioral responses.
Auditory Masking
Sound can disrupt behavior through masking, or interfering with, an
animal's ability to detect, recognize, or discriminate between acoustic
signals of interest (e.g., those used for intraspecific communication
and social interactions, prey detection, predator avoidance, or
navigation) (Richardson et al. 1995; Erbe and Farmer 2000; Tyack 2000;
Erbe et al. 2016). Masking occurs when the receipt of a sound is
interfered with by another coincident sound at similar frequencies and
at similar or higher intensity, and may occur whether the sound is
natural (e.g., snapping shrimp, wind, waves, precipitation) or
anthropogenic (e.g., shipping, sonar, seismic exploration) in origin.
The ability of a noise source to mask biologically important sounds
depends on the characteristics of both the noise source and the signal
of interest (e.g., signal-to-noise ratio, temporal variability,
direction), in relation to each other and to an animal's hearing
abilities (e.g., sensitivity, frequency range, critical ratios,
frequency discrimination, directional discrimination, age, or TTS
hearing loss), and existing ambient noise and propagation conditions.
Masking these acoustic signals can disturb the behavior of individual
animals, groups of animals, or entire populations. Masking can lead to
behavioral changes including vocal changes (e.g., Lombard effect,
increasing amplitude, or changing frequency), cessation of foraging,
and leaving an area, to both signalers and receivers, in an attempt to
compensate for noise levels (Erbe et al. 2016). Masking only occurs in
the presence of the masking noise and does not persist after the
cessation of the noise. Masking may lead to a change in vocalizations
or a change in behavior (e.g., cessation of foraging, leaving an area).
Masking by explosive detonation sounds would not be expected, given the
short duration, and there are no direct observations of masking in
marine mammals due to exposure to sound from explosive detonations.
Physiological Stress
There is growing interest in monitoring and assessing the impacts
of stress responses to sound in marine animals. Classic stress
responses begin when an animal's central nervous system perceives a
potential threat to its homeostasis. That perception triggers stress
responses regardless of whether a stimulus actually threatens the
animal; the mere perception of a threat is sufficient to trigger a
stress response (Moberg 2000; Sapolsky et al. 2005; Seyle 1950). Once
an animal's central nervous system perceives a threat, it mounts a
biological response or defense that consists of a combination of the
four general biological defense responses: behavioral responses,
autonomic nervous system responses, neuroendocrine responses, or immune
responses.
According to Moberg (2000), in the case of many stressors, an
animal's first and sometimes most economical (in terms of biotic costs)
response is behavioral avoidance of the potential stressor or avoidance
of continued exposure to a stressor. An animal's second line of defense
to stressors involves the sympathetic part of the autonomic nervous
system and the classical ``fight or flight'' response which includes
the cardiovascular system, the gastrointestinal system, the exocrine
glands, and the adrenal medulla to produce changes in heart rate, blood
pressure, and gastrointestinal activity that humans commonly
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associate with ``stress.'' These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's welfare.
An animal's third line of defense to stressors involves its
neuroendocrine systems or sympathetic nervous systems; the system that
has received the most study has been the hypothalamus-pituitary-adrenal
system (also known as the HPA axis in mammals or the hypothalamus-
pituitary-interrenal axis in fish and some reptiles). Unlike stress
responses associated with the autonomic nervous system, virtually all
neuro-endocrine functions that are affected by stress--including immune
competence, reproduction, metabolism, and behavior--are regulated by
pituitary hormones. Stress-induced changes in the secretion of
pituitary hormones have been implicated in failed reproduction (Moberg,
1987; Rivier and Rivest 1991), altered metabolism (Elasser et al.
2000), reduced immune competence (Blecha 2000), and behavioral
disturbance (Moberg 1987; Blecha 2000). Increases in the circulation of
glucocorticosteroids (cortisol, corticosterone, and aldosterone in
marine mammals; see Romano et al. 2004) have been equated with stress
for many years.
Because there are many unknowns regarding the occurrence of
acoustically induced stress responses in marine mammals, it is assumed
that any physiological response (e.g., hearing loss or injury) or
significant behavioral response is also associated with a stress
response.
Munition Strike
Another potential risk to marine mammals is direct strike by
ordnance, in which the ordnance physically hits an animal. Based on the
dispersed distribution of marine mammals in the open ocean, the
relatively short amount of time they spend at the water surface
compared with the time they spend underwater, and the annual quantities
of munitions proposed to be expended, it is highly improbable that a
marine mammal would be directly struck by a munition during EGTTR
operations. This conclusion, which NMFS concurs with, was reached in
the previous 2015 REA (USAF 2015). The Air Force did not request take
of marine mammals by direct munition strikes, as it is not anticipated,
and it is not analyzed further.
Marine Mammal Habitat
Impacts on marine mammal habitat are part of the consideration in
making a finding of negligible impact on the species and stocks of
marine mammals. Habitat includes, but is not necessarily limited to,
rookeries, mating grounds, feeding areas, and areas of similar
significance. We have preliminarily determined USAF's proposed
activities would not result in permanent effects on the habitats used
by the marine mammals in the EGTTR, including the availability of prey
(i.e. fish and invertebrates). While it is anticipated that the
proposed activity may result in marine mammals avoiding certain areas
due to temporary ensonification, any impact to habitat is temporary and
reversible and was considered in further detail earlier in this
document, as behavioral modification. The main impact associated with
the proposed activity will be temporarily elevated noise levels and the
associated direct effects on marine mammals, previously discussed in
this proposed rule.
Sound may affect marine mammals through impacts on the abundance,
behavior, or distribution of prey species (e.g., crustaceans,
cephalopods, fish, zooplankton). Marine mammal prey varies by species,
season, and location and, for some species, is not well documented.
Here, we describe studies regarding the effects of noise on known
marine mammal prey.
Effects on Fish--Fish utilize the soundscape and components of
sound in their environment to perform important functions such as
foraging, predator avoidance, mating, and spawning (e.g., Zelick et al.
1999; Fay 2009). The most likely effects on fishes exposed to loud,
intermittent, low-frequency sounds are behavioral responses (i.e.,
flight or avoidance). Short duration, sharp sounds (such as pile
driving or air guns) can cause overt or subtle changes in fish behavior
and local distribution. The reaction of fish to acoustic sources
depends on the physiological state of the fish, past exposures,
motivation (e.g., feeding, spawning, migration), and other
environmental factors. Key impacts to fishes may include behavioral
responses, hearing damage, barotrauma (pressure-related injuries), and
mortality.
Fishes, like other vertebrates, have a variety of different sensory
systems to glean information from ocean around them (Astrup and Mohl
1993; Astrup 1999; Braun and Grande 2008; Carroll et al. 2017; Hawkins
and Johnstone 1978; Ladich and Popper 2004; Ladich and Schulz-Mirbach
2016; Nedwell et al. 2004; Popper et al. 2003; Popper et al. 2005).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al. 2008) (terrestrial vertebrates generally
only detect pressure). Most marine fishes primarily detect particle
motion using the inner ear and lateral line system, while some fishes
possess additional morphological adaptations or specializations that
can enhance their sensitivity to sound pressure, such as a gas-filled
swim bladder (Braun and Grande 2008; Popper and Fay 2011).
Hearing capabilities vary considerably between different fish
species with data only available for just over 100 species out of the
34,000 marine and freshwater fish species (Eschmeyer and Fong 2016). In
order to better understand acoustic impacts on fishes, fish hearing
groups are defined by species that possess a similar continuum of
anatomical features which result in varying degrees of hearing
sensitivity (Popper and Hastings 2009a). There are four hearing groups
defined for all fish species (modified from Popper et al. 2014) within
this analysis and they include: fishes without a swim bladder (e.g.,
flatfish, sharks, rays, etc.); fishes with a swim bladder not involved
in hearing (e.g., salmon, cod, pollock, etc.); fishes with a swim
bladder involved in hearing (e.g., sardines, anchovy, herring, etc.);
and fishes with a swim bladder involved in hearing and high-frequency
hearing (e.g., shad and menhaden). Currently, less data are available
to estimate the range of best sensitivity for fishes without a swim
bladder.
In terms of behavioral responses of fish, Juanes et al. (2017)
discuss the potential for negative impacts from anthropogenic
soundscapes on fish, but the authors' focus was on broader based
sounds, such as ship and boat noise sources. Occasional behavioral
reactions to intermittent explosions occurring at or near the surface
are unlikely to cause long-term consequences for individual fish or
populations; there are no detonations of explosives occurring
underwater from the proposed activities. Fish that experience hearing
loss as a result of exposure to explosions may have a reduced ability
to detect relevant sounds, such as predators, prey, or social
vocalizations. However, PTS has not been known to occur in fishes and
any hearing loss in fish may be as temporary as the timeframe required
to repair or replace the sensory cells that were damaged or destroyed
(Popper et al. 2005; Popper et al. 2014; Smith et al. 2006). It is not
known if damage to auditory nerve fibers could occur, and if so,
whether fibers would recover during this process. It is also possible
for fish to be injured or killed by an explosion in the immediate
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vicinity of the surface from dropped or fired ordnance. Physical
effects from pressure waves generated by detonations at or near the
surface could potentially affect fish within proximity of training or
testing activities. The shock wave from an explosion occurring at or
near the surface may be lethal to fish at close range, causing massive
organ and tissue damage and internal bleeding (Keevin and Hempen,
1997). At greater distance from the detonation point, the extent of
mortality or injury depends on a number of factors including fish size,
body shape, orientation, and species (Keevin and Hempen, 1997; Wright,
1982). At the same distance from the source, larger fish are generally
less susceptible to death or injury, elongated forms that are round in
cross-section are less at risk than deep-bodied forms, and fish
oriented sideways to the blast suffer the greatest impact (Edds-Walton
and Finneran 2006; Wiley et al. 1981; Yelverton et al. 1975). Species
with gas-filled organs are more susceptible to injury and mortality
than those without them (Gaspin, 1975; Gaspin et al. 1976; Goertner et
al. 1994).
Training and testing exercises involving explosions at or near the
surface are dispersed in space and time; therefore, repeated exposure
of individual fishes are unlikely. Mortality and injury effects to
fishes from explosives would be localized around the area of a given
explosion at or above the water surface, but only if individual fish
and the explosive at the surface were co-located at the same time.
Fishes deeper in the water column or on the bottom would not be
affected by surface explosions. Most acoustic effects, if any, are
expected to be short term and localized. Long-term consequences for
fish populations, including key prey species within the EGTTR Area,
would not be expected.
Effects on Invertebrates--In addition to fish, prey sources such as
marine invertebrates could potentially be impacted by sound stressors
as a result of the proposed activities. However, most marine
invertebrates' ability to sense sounds is very limited. In most cases,
marine invertebrates would not respond to impulsive sounds. Data on
response of invertebrates such as squid, another marine mammal prey
species, to anthropogenic sound has been documented (de Soto 2016; Sole
et al. 2017). Explosions could kill or injure nearby marine
invertebrates. Vessels also have the potential to impact marine
invertebrates by disturbing the water column or sediments, or directly
striking organisms (Bishop 2008). The propeller wash (water displaced
by propellers used for propulsion) from vessel movement and water
displaced from vessel hulls can potentially disturb marine
invertebrates in the water column and are a likely cause of zooplankton
mortality (Bickel et al. 2011). The localized and short-term exposure
to explosions or vessels at or near the surface could displace, injure,
or kill zooplankton, invertebrate eggs or larvae, and macro-
invertebrates. However, mortality or long-term consequences for a few
animals is unlikely to have measurable effects on overall populations.
As with fish, cumulatively individual and population-level impacts from
exposure to explosives at or above the water surface are not
anticipated, and impacts would be short term and localized, and would
likely be inconsequential to invertebrate populations, and to the
marine mammals that use them as prey.
Expended Materials--Military expended materials resulting from
training and testing activities could potentially result in minor long-
term changes to benthic habitat, however the impacts of small amounts
of expended materials are unlikely to have measurable effects on
overall populations. Military expended materials may be colonized over
time by benthic organisms that prefer hard substrate and would provide
structure that could attract some species of fish or invertebrates.
Overall, the combined impacts of explosions and military expended
materials resulting from the proposed activities would not be expected
to have measurable effects on populations of marine mammal prey
species. Prey species exposed to sound might move away from the sound
source or show no obvious direct effects at all, but a rapid return to
normal recruitment, distribution, and behavior is anticipated. Long-
term consequences to fish or marine invertebrate populations would not
be expected as a result of exposure to sounds or vessels in the EGTTR.
Acoustic Habitat--Acoustic habitat is the soundscape which
encompasses all of the sound present in a particular location and time,
as a whole, when considered from the perspective of the animals
experiencing it. Animals produce sound for, or listen for sounds
produced by, conspecifics (communication during feeding, mating, and
other social activities), other animals (finding prey or avoiding
predators), and the physical environment (finding suitable habitats,
navigating). Together, sounds made by animals and the geophysical
environment (e.g., produced by earthquakes, lightning, wind, rain,
waves) make up the natural contributions to the total acoustics of a
place. These acoustic conditions, termed acoustic habitat, are one
attribute of an animal's total habitat.
Soundscapes are also defined by, and acoustic habitat influenced
by, the total contribution of anthropogenic sound. This may include
incidental emissions from sources, such as vessel traffic or may be
intentionally introduced to the marine environment for data acquisition
purposes (e.g., as in the use of air gun arrays) or USAF training and
testing purposes (as in the use of explosives). Anthropogenic noise
varies widely in its frequency, content, duration, and loudness, and
these characteristics greatly influence the potential habitat-mediated
effects to marine mammals, which may range from local effects for brief
periods of time to chronic effects over large areas and for long
durations. Depending on the extent of effects to habitat, animals may
alter their communications signals (thereby potentially expending
additional energy) or miss acoustic cues (either conspecific or
adventitious). Problems arising from a failure to detect cues are more
likely to occur when noise stimuli are chronic and overlap with
biologically relevant cues used for communication, orientation, and
predator/prey detection (Francis and Barber, 2013). For more detail on
these concepts see Pijanowski et al. 2011; Francis and Barber 2013;
Lillis et al. 2014. We do not anticipate these problems arising from at
or near surface explosions during training and testing activities as
they would be either widely dispersed or concentrated in small areas
for shorter periods of time. Sound produced from training and testing
activities in the EGTTR would be temporary and transitory; the affected
area would be expected to immediately return to the original state when
these activities cease.
Marine Water Quality--Training and testing activities may introduce
water quality constituents into the water column. Metals are the
dominant constituent by weight of bombs, missiles, gun ammunition, and
other munitions, including inert munitions, used during EGTTR training
and testing operations. Some targets used during EGTTR missions also
contain metals, including CONEX and hopper barge targets used for PSW
tests and certain components of remotely controlled target boats.
Metals contained in casing fragments of detonated munitions, intact
inert munitions, unexploded ordnance, and other mission-related debris
will corrode from exposure to seawater. The
[[Page 8169]]
rate of corrosion depends on the metal type and the extent to which the
item is directly exposed to seawater, which can be influenced by
existing corrosion on the item, and how much the item may be encrusted
by marine organisms and/or buried in sediments. Aluminum and steel,
which is composed mostly of iron, comprise the bulk of the metal that
enters the marine environment from EGTTR operations. Iron and aluminum
are relatively benign metals in terms of toxicity. Chromium, lead, and
copper, which make up a relatively small percentage of the overall
metal input into the marine environment from EGTTR operations, have
higher toxicity effects. Through its lifetime in the marine
environment, a portion of the overall metal content would dissolve,
depending on the solubility of the material. Dissolved metals would
readily undergo mixing and dilution and would have no appreciable
effect on water quality or marine life within the water column. Metals
in particulate form would be released into sediments through the
corrosion process. Elevated levels of undissolved metals in sediments
would be restricted to a relatively small area around the metal-
containing item and any associated impacts to water quality would be
negligible.
Munitions used for EGTTR training and testing operations contain a
wide variety of explosives, including TNT, RDX, HMX, Composition B,
Tritonal, AFX-757, PBXN, and others. During live missions in the EGTTR,
explosives can enter the marine environment via high-order detonations,
which occur when the munition functions as intended and the vast
majority of explosives are consumed; low-order detonations, which occur
when the munition partially functions and only a portion of the
explosives are consumed; and unexploded munitions, which fail to
detonate with no explosives consumed. During high-order detonations, a
residual amount of the explosive material, typically less than 1
percent, would be unconsumed and released into the environment (Walsh
et al. 2011). The majority of live munitions used during EGTTR
operations are successfully detonated as intended. During low-order
detonations, a residual amount of explosives associated with the
detonation and the remaining unconsumed portion of the explosive fill
would enter the marine environment. If the munition does not explode,
it becomes unexploded ordnance (UXO). In this case, all the explosive
material would remain within the munition casing and enter the marine
environment with explosives potentially being released due to corrosion
or rupture. Explosives and explosives by-products released into the
marine environment can be removed via biodegradation, and expended or
disposed military munitions on the seafloor do not result in excessive
accumulation of explosives in sediments or significant degradation of
sediment quality by explosives. Given that high-order detonations
consume the vast majority of explosive material in the munition,
successful detonations are considered a negligible source of explosives
released into the marine environment.
Estimated Take of Marine Mammals
This section indicates the number of takes that NMFS is proposing
to authorize, which is based on the maximum amount that is reasonably
likely to occur, depending on the type of take and the methods used to
estimate it, as described in detail below. NMFS preliminarily agrees
that the methods the USAF has put forth described herein to estimate
take (including the model, thresholds, and density estimates), and the
resulting numbers estimated for authorization, are appropriate and
based on the best available science.
All takes are by harassment. For a military readiness activity, the
MMPA defines ``harassment'' as (i) Any act that injures or has the
significant potential to injure a marine mammal or marine mammal stock
in the wild (Level A Harassment); or (ii) Any act that disturbs or is
likely to disturb a marine mammal or marine mammal stock in the wild by
causing disruption of natural behavioral patterns, including, but not
limited to, migration, surfacing, nursing, breeding, feeding, or
sheltering, to a point where such behavioral patterns are abandoned or
significantly altered (Level B Harassment). No serious injury or
mortality of marine mammals is expected to occur.
Proposed authorized takes would primarily be in the form of Level B
harassment, as use of the explosive sources may result, either directly
or as result of TTS, in the disruption of natural behavioral patterns
to a point where they are abandoned or significantly altered (as
defined specifically at the beginning of this section, but referred to
generally as behavioral disruption). There is also the potential for
Level A harassment, in the form of auditory injury to result from
exposure to the sound sources utilized in training and testing
activities. As described in this Estimated Take of Marine Mammals
section, no non-auditory injury is anticipated or proposed for
authorization, nor is any serious injury or mortality.
Generally speaking, for acoustic impacts NMFS estimates the amount
and type of harassment by considering: (1) acoustic thresholds above
which NMFS believes the best available science indicates marine mammals
will be taken by Level B harassment or incur some degree of temporary
or permanent hearing impairment; (2) the area or volume of water that
will be ensonified above these levels in a day or event; (3) the
density or occurrence of marine mammals within these ensonified areas;
and (4) the number of days of activities or events. This analysis of
the potential impacts of the proposed activities on marine mammals was
conducted by using the spatial density models developed by NOAA's
Southeast Fisheries Science Center for the species in the Gulf of
Mexico (NOAA 2022). The density model integrated visual observations
from aerial and shipboard surveys conducted in the Gulf of Mexico from
2003 to 2019.
The munitions proposed to be used by each military unit were
grouped into mission-day categories so the acoustic impact analysis
could be based on the total number of detonations conducted during a
given mission to account for the accumulated energy from multiple
detonations over a 24-hour period. A total of 19 mission-day categories
were developed for the munitions proposed to be used. Using the dBSea
underwater acoustic model and associated analyses, the threshold
distances associated with Level A harassment (PTS) and Level B (TTS and
behavioral) harassment zones were estimated for each mission-day
category for each marine mammal species. Takes were estimated based on
the area of the harassment zones, predicted animal density, and annual
number of events for each mission-day category. To assess the potential
impacts of inert munitions on marine mammals, the proposed inert
munitions were categorized into four classes based on their impact
energies, and the threshold distances for each class were modeled and
calculated as described for the mission-day categories.
Acoustic Thresholds
Using the best available science, NMFS has established acoustic
thresholds that identify the most appropriate received level of
underwater sound above which marine mammals exposed to these sound
sources could be reasonably expected to directly experience a
disruption in behavior patterns to a point where they are abandoned or
significantly altered,
[[Page 8170]]
to incur TTS (equated to Level B harassment), or to incur PTS of some
degree (equated to Level A harassment). Thresholds have also been
developed to identify the pressure levels above which animals may incur
non-auditory injury from exposure to pressure waves from explosive
detonation. Refer to the Criteria and Thresholds for U.S. Navy Acoustic
and Explosive Effects Analysis (Phase III) report (U.S. Department of
the Navy 2017c) for detailed information on how the criteria and
thresholds were derived.
Hearing Impairment (TTS/PTS), Tissues Damage, and Mortality
NMFS' Acoustic Technical Guidance (NMFS 2018) identifies dual
criteria to assess auditory injury (Level A harassment) to five
different marine mammal groups (based on hearing sensitivity) as a
result of exposure to noise from two different types of sources
(impulsive or non-impulsive). The Acoustic Technical Guidance also
identifies criteria to predict TTS, which is not considered injury and
falls into the Level B harassment category. The USAF's proposed
activity only includes the use of impulsive (explosives) sources. These
thresholds (Table 20) were developed by compiling and synthesizing the
best available science and soliciting input multiple times from both
the public and peer reviewers. The references, analysis, and
methodology used in the development of the thresholds are described in
Acoustic Technical Guidance, which may be accessed at: <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 20 to predict the
onset of TTS, PTS, tissue damage, and mortality for explosives
(impulsive) and other impulsive sound sources.
Table 20--Onset of TTS, PTS, Tissue Damage, and Mortality Thresholds for Marine Mammals for Explosives and Other Impulsive Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mean onset
Functional hearing group Species Onset TTS Onset PTS Mean onset slight slight lung Mean onset
GI tract injury injury mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans......... Rice's whale....... 168 dB SEL 183 dB SEL 237 dB Peak SPL.... Equation 1 Equation 2
(weighted) or 213 (weighted) or 219
dB Peak SPL. dB Peak SPL.
Mid-frequency cetaceans......... Dolphins........... 170 dB SEL 185 dB SEL 237 dB Peak SPL....
(weighted) or 224 (weighted) or 230
dB Peak SPL. dB Peak SPL.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes: Equation 1: 47.5M\1/3\ (1+[DRm/10.1])\1/6\ Pa-sec. Equation 2: 103M\1/3\ (1+[DRm/10.1])\1/6\ Pa-sec. M = mass of the animals in kg; DRm = depth
of the receiver (animal) in meters; SPL = sound pressure level.
Refer to the Criteria and Thresholds for U.S. Navy Acoustic and
Explosive Effects Analysis (Phase III) report (U.S. Department of the
Navy, 2017c) for detailed information on how the criteria and
thresholds were derived. Non-auditory injury (i.e., other than PTS) and
mortality are so unlikely as to be discountable under normal conditions
and are therefore not considered further in this analysis.
Behavioral Disturbance
Though significantly driven by received level, the onset of Level B
harassment by direct behavioral disturbance from anthropogenic noise
exposure is also informed to varying degrees by other factors related
to the source (e.g., frequency, predictability, duty cycle, distance),
the environment (e.g., bathymetry), and the receiving animals (hearing,
motivation, experience, demography, behavioral context) and can be
difficult to predict (Ellison et al. 2011; Southall et al. 2007). Based
on what the available science indicates and the practical need to use
thresholds based on a factor or factors that are both predictable and
measurable for most activities, NMFS uses generalized acoustic
thresholds based primarily on received level (and distance in some
cases) to estimate the onset of Level B harassment by behavioral
disturbance.
Explosives--Explosive thresholds for Level B harassment by
behavioral disturbance for marine mammals are the hearing groups' TTS
thresholds minus 5 dB (see Table 21 below for the TTS thresholds for
explosives) for events that contain multiple impulses from explosives
underwater. See the Criteria and Thresholds for U.S. Navy Acoustic and
Explosive Effects Analysis (Phase III) report (U.S. Department of the
Navy 2017c) for detailed information on how the criteria and thresholds
were derived. NMFS continues to concur that this approach represents
the best available science for determining behavioral disturbance of
marine mammals from multiple explosives. While marine mammals may also
respond to single explosive detonations, these responses are expected
to more typically be in the form of startle reaction, rather than a
disruption in natural behavioral patterns to the point where they are
abandoned or significantly altered. On the rare occasion that a single
detonation might result in a more severe behavioral response that
qualifies as Level B harassment, it would be expected to be in response
to a comparatively higher received level. Accordingly, NMFS considers
the potential for these responses to be quantitatively accounted for
through the application of the TTS threshold, which, as noted above, is
5 dB higher than the behavioral harassment threshold for multiple
explosives.
Table 21--Thresholds for Level B Harassment by Behavioral Disturbance
for Explosives for Marine Mammals
------------------------------------------------------------------------
SEL
Medium Functional hearing group (weighted)
------------------------------------------------------------------------
Underwater................... LF 163
Underwater................... MF 165
------------------------------------------------------------------------
Note: Weighted SEL thresholds in dB re 1 [mu]Pa\2\s underwater. LF = low-
frequency, MF = mid-frequency, HF = high-frequency.
USAF's Acoustic Effects Model
The USAF's Acoustic Effects Model calculates sound energy
propagation from explosives during UASF activities in the EGTTR. The
net explosive weight (NEW) of a munition at impact can be directly
correlated with the energy in the impulsive pressure wave generated by
the warhead detonation. The NEWs of munitions addressed as part of this
proposed rule range from 0.1 lb (0.04 kg) for small projectiles to 945
lb (428.5kg) for the largest bombs. The explosive materials used in
these munitions also vary considerably with different formulations used
to produce different intended effects. The primary detonation metrics
directly considered and used for modeling analysis are the peak impulse
pressure and duration of the impulse. An integration of the
[[Page 8171]]
pressure of an impulse over the duration (time) of an impulse provides
a measure of the energy in an impulse. Some of the NEWs of certain
types of munitions, such as missiles, are associated with the
propellant used for the flight of the munition. This propellant NEW is
unrelated to the NEW of the warhead, which is the primary source of
explosive energy in most munitions. The propellant of a missile fuels
the flight phase and is mostly consumed prior to impact. Missile
propellant typically has a lower flame speed than warhead explosives
and is relatively insensitive to detonation from impacts but burns
readily. A warhead detonation provides a high-pressure, high-velocity
flame front that may cause burning propellant to detonate; therefore,
this analysis assumes that the unconsumed residual propellant that
remains at impact contributes to the detonation-induced pressure
impulse in the water. The impact analysis assumes that 20 percent of
the propellant remains unconsumed in missiles at impact; this
assumption is based on input from user groups and is considered a
reasonable estimate for the purpose of analysis. The NEW associated
with this unconsumed propellant is added to the NEW of the warhead to
derive the total energy released by the detonation. Absent a warhead
detonation, it is assumed that continued burning or deflagration of
unconsumed residual propellant does not contribute to the pressure
impulse in the water; this applies to inert missiles that lack a
warhead but contain propellant for flight.
In addition to the energy associated with the detonation, energy is
also released by the physical impact of the munition with the water.
This kinetic energy has been calculated and incorporated into the
estimations of munitions energy for both live and inert munitions in
this proposed rule. The kinetic energy of the munition at impact is
calculated as one half of the munition mass times the square of the
munition velocity. The initial impact event contributing to the
pressure impulse in water is assumed to be 1 millisecond in duration.
To calculate the velocity (and kinetic energy) immediately after
impact, the deceleration contributing to the pressure impulse in the
water is assumed for all munitions to be 1,500 g-forces, or 48,300 feet
per square second over 1 millisecond. A substantial portion of the
change in kinetic energy at impact is dissipated as a pressure impulse
in the water, with the remainder being dissipated through structural
deformation of the munition, heat, displacement of water, and other
smaller energy categories. Even with 1,500 g-forces of deceleration,
the change in velocity over this short time period is small and is
proportional to the impact velocity and munition mass. The impact
energy is the portion of the kinetic energy at impact that is
transmitted as an underwater pressure impulse, expressed in units of
trinitrotoluene-equivalent (TNTeq). The impact energies of the proposed
live munitions were calculated and included in their total energy
estimations. The impact energies of the inert munitions proposed to be
used were also calculated. To assess the potential impacts of inert
munitions on marine animals, the inert munitions were categorized based
on their impact energies into the following four classes of 2 lb (0.9
kg), 1 lb (0.45 kg), 0.5 lb (0.22 kg), and 0.15 lb (0.07 kg) TNTeq;
these values correspond closely to the actual or average impact energy
values of the munitions and are rounded for the purpose of analysis.
The 2 lb class represents the largest inert bomb, which includes the
Mark (Mk)-84 General Purpose (GP), Guided Bomb Unit (GBU)-10, and GBU-
31 bombs, whereas the 1 lb class represents the largest inert missile,
which is the Air-to-Ground Missile (AGM)-158 Joint Air-to-Surface
Standoff Missile (JASSM). The JASSM has greater mass but lower impact
energy than the GBU-31; this is because of the JASSM's lower velocity
at impact and associated change in velocity over the deceleration
period, which contributes to the pressure impulse. The 0.5 lb and 0.15
lb impact energy classes each represent the approximate average impact
energy of multiple munitions, with the 0.5 lb class representing
munitions with mid-level energies, and the 0.15 lb class representing
munitions with the lowest energies (Table 22).
Table 22--Impact Energy Classes for Proposed Inert Munitions
----------------------------------------------------------------------------------------------------------------
Impact energy class (lb TNTeq)/ Approximate weight (lb)/ Approximate velocity
(kg) Representative munitions (kg) (mach)
----------------------------------------------------------------------------------------------------------------
2 (0.9)......................... Mk-84, GBU-10, and GBU- 2,000 (907)............. 1.1.
31.
1 (0.45)........................ AGM-158 JASSM........... 2,250 (1020.3).......... 0.9.
0.5 (0.22)...................... GBU-54 and AIM-120...... 250 to 650 (113.4 to Variable.
294.8).
0.15 (0.07)..................... AIM-9, GBU-39, and PGU- 1 to 285 (0.5 to 129.2). Variable.
15.
----------------------------------------------------------------------------------------------------------------
The NEW associated with the physical impact of each munition and
the unconsumed propellant in certain munitions is added to the NEW of
the warhead to derive the NEW at impact (NEWi) for each live munition.
The NEWi of each munition was then used to calculate the peak pressure
and pressure decay for each munition. This results in a more accurate
estimate of the actual energy released by each detonation. Extensive
research since the 1940s has shown that each explosive formulation
produces unique correlations to explosive performance metrics. The peak
pressure and pressure decay constant depend on the NEW, explosive
formulation, and distance from the detonation. The peak pressure and
duration of the impulse for each munition can be calculated empirically
using similitude equations, with constants used in these equations
determined from experimental data (NSWC 2017). The explosive-specific
similitude constants and munition-specific NEWi were used for
calculating the peak pressure and pressure decay for each munition
analyzed. It should be noted that this analysis assumes that all
detonations occur in the water and none of the detonations occur above
the water surface when a munition impacts a target. This exceptionally
conservative assumption implies that all munition energy is imparted to
the water rather than the intended targets. See Appendix A in the LOA
application for detailed explanations of similitude equations.
The following standard metrics are used to assess underwater
pressure and impulsive noise impacts on marine animals:
<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
[[Page 8172]]
the pressure impulse. This metric provides a measure of energy in the
form of time-integrated pressure. Units are typically pascal-seconds
(Pa[middot]s) or pounds per square inch (psi) per millisecond (msec)
(psi[middot]msec). The positive impulse for a given munition can be
explicitly calculated at a given distance using the similitude
equations and integrating the pressure over the initial positive phase
of the pressure impulse.
The munition-specific peak pressure and pressure decay at various
radii were used to determine the species-specific distance to effect
threshold for mortality, non-auditory injury, peak pressure-induced
permanent threshold shift (PTS) in hearing and peak pressure-induced
temporary threshold shift (TTS) in hearing for each species. The
munition-specific peak pressures and decays for all munitions in each
mission-day category were used as a time-series input in the dBSea
underwater acoustic model to determine the distance to effect for
cumulative SEL-based (24-hour) PTS, TTS, and behavioral effects for
each species for each mission day.
The dBSea model was conducted using a constant sound speed profile
(SSP) of 1500 m/s to be both representative of local conditions and to
prevent thermocline induced refractions from distorting the analysis
results. Salinity was assumed to be 35 parts per thousand (ppt) and pH
was 8. The water surface was treated as smooth (no waves) to
conservatively eliminate diffraction induced attenuation of sound.
Currents and tidal flow were treated as zero. Energy expended on the
target and/or on ejecting water or transfer into air was ignored and
all weapon energy was treated as going into underwater acoustic energy
to be conservative. Finally, the bottom was treated as sand with a
sound speed of 1650 m/s and an attenuation of 0.8 dB/wavelength.
The harassment zone is the area or volume of ocean in which marine
animals could be exposed to various pressure and impulsive noise levels
generated by a surface or subsurface detonation that would result in
mortality; non-auditory injury and PTS (Level A harassment impacts);
and TTS and behavioral impacts (Level B harassment impacts). The
harassment zones for the proposed detonations were estimated using
Version 2.3 of the dBSea model for cumulative SEL and using explicit
similitude equations for SPL and positive impulse. The characteristics
of the impulse noise at the source were calculated based on munition-
specific data including munition mass at impact, munition velocity at
impact, NEW of warheads, explosive-specific similitude data, and
propellant data for missiles. Table 23 presents the source-level SPLs
(at r = 1 meter) calculated for the proposed munitions.
Table 23--Calculated Source SPLs for Munitions
--------------------------------------------------------------------------------------------------------------------------------------------------------
Peak pressure and decay values
Warhead NEW Model NEWi -----------------------------------------------
Type (lb)/(kg) Modeled explosive (lm)/(kg) Pmax @1 m SPL @1 m dB re
(psi) 1 mPa [Theta] msec
--------------------------------------------------------------------------------------------------------------------------------------------------------
AGM-158 JASSM All Variants.............. 240.26 (108.9) Tritonal...................... 241.36 (109.5) 45961.4858 290.0 0.320
GBU-54 KMU-572C/B, B/B.................. 192 (87.1) Tritonal...................... 192.3 (87.2) 42101.8577 289.3 0.302
AGM-65 (all variants)................... 85 (38.5) Comp B........................ 98.3 (44.6) 37835.4932 288.3 0.200
AIM-120C3............................... 15 (6.8) PBXN-110...................... 36.18 (13.4) 24704.864 284.6 0.167
AIM-9X Blk I............................ 7.7 (3.5) PBXN-110...................... 20 (9.1) 19617.2833 282.6 0.143
AGM-114 (All ex R2 with TM(R10))........ 9 (4.1) PBXN-110...................... 13.08 (5.9) 16630.2435 281.2 0.128
AGM-179 JAGM............................ 9 (4.1) PBXN-110...................... 13.08 (5.9) 16630.2435 281.2 0.128
AGM-114 R2 with TM (R10)................ 8 (3.6) PBXN-9........................ 13.08 (5.9) 17240.2131 281.5 0.124
AGR-20 (APKWS).......................... 2.3 (1.0) Comp B........................ 3.8 (1.7) 10187.8419 276.9 0.090
PGU-43 (105 mm)......................... 4.7 (2.1) Comp B........................ 4.72 (2.1) 11118.8384 277.7 0.095
GBU-69.................................. 36 (16.3) Tritonal...................... 36.1 (16.4) 22074.1015 283.7 0.198
GBU-70.................................. 36 (16.3) Tritonal...................... 36.1 (19.4) 22074.1015 283.7 0.198
GBU-39 SDB (GTV)........................ 0.39 (0.2) PBXN-9........................ 0.49 (0.2) 4757.6146 270.3 0.054
GBU-53/B (GTV).......................... 0.34 (0.2) PBXN-9........................ 0.44 (0.2) 4561.06062 270.0 0.053
GBU-12.................................. 192 (87.1) Tritonal...................... 192.3 (87.2) 42101.8577 289.3 0.302
Mk-81 (GP 250 lb)....................... 100 (45.4) H-6........................... 100 (45.4) 38017.3815 288.4 0.237
--------------------------------------------------------------------------------------------------------------------------------------------------------
[thgr] = shock wave time constant; AGM = Air-to-Ground Missile; AIM = Air Intercept Missile; APKWS = Advanced Precision Kill Weapon System; dB re 1
[micro]Pa = decibel(s) referenced to 1 micropascal; FU = Full Up; GBU = Guided Bomb Unit; GP = General Purpose; GTV = Guided Test Vehicle; HACM =
Hypersonic Attack Cruise Missile; HE = High Explosive; JASSM = Joint Air-to-Surface Standoff Missile; lb = pound(s); lbm = pound-mass; LSDB = Laser
Small-Diameter Bomb; m = meter(s); Mk = Mark; mm = millimeter(s); msec = millisecond(s); NEW = net explosive weight; NEWi = net explosive weight at
impact; NLOS = Non-Line-of-Sight; PGU = Projectile Gun Unit; Pmax = shock wave peak pressure; psi = pound(s) per square inch; SDB = Small-Diameter
Bomb; SPL = sound pressure level; TM = telemetry.
For SEL analysis, the dBSea model was used with the ray-tracing
option for calculating the underwater transmission of impulsive noise
sources represented in a time series (1,000,000 samples per second) as
calculated using similitude equations (r = 1 meter) for each munition
for each mission day. All surface detonations are assumed to occur at a
depth of 1 m, and all subsurface detonations, which would include the
GBU-10, GBU-24, GBU-31, and subsurface mines, are assumed to occur at a
depth of 3 m. The model used bathymetry for LIA with detonations
occurring at the center of the LIA with a water depth of 70 m. The
seafloor of the LIA is generally sandy, so sandy bottom characteristics
for reflectivity and attenuation were used in the dBSea model, as
previously described. The model was used to calculate impulsive
acoustic noise transmission on one-third octaves from 31.5 hertz to 32
kilohertz. Maximum SELs from all depths projected to the surface were
used for the analyses.
The cumulative SEL is based on multiple parameters including the
acoustic characteristics of the detonation and sound propagation loss
in the marine environment, which is influenced by a number of
environmental factors including water depth and seafloor properties.
Based on integration of these parameters, the dBSea model predicts the
distances at which each marine animal species is estimated to
experience SELs associated with the onset of PTS, TTS, and behavioral
disturbance. As noted previously, thresholds for the onset of TTS and
PTS used in the model and pressure calculations are based on those
presented in Criteria and Thresholds for U.S. Navy Acoustic and
Explosive Effects Analysis (Phase III) (DoN 2017) for cetaceans with
mid- to high-frequency hearing (dolphins) and low-frequency hearing
(Rice's whale). Behavioral thresholds are set 5 dB
[[Page 8173]]
below the SEL-based TTS threshold. Table 24 shows calculated SPLs and
SELs for the designated mission-day categories.
Table 24--Calculated Source SPLs and SELs for Mission-Day Categories
----------------------------------------------------------------------------------------------------------------
Total warhead Source
Mission day NEW, lbm \a\ Modeled NEWi, lbm/ cumulative Source peak
(kg) (kg) SEL, dB SPL, dB
----------------------------------------------------------------------------------------------------------------
A......................................... 2402.6 (108.6) 2413.6 (1094.6) 262.1 290
B......................................... 1961 (889.3) 2029.9 (920.6) 261.4 289.3
C......................................... 1145 (519.2) 1376.2 (624.1) 259.8 288.3
D......................................... 562 (254.8) 836.22 (379.2) 257.6 288.3
E......................................... 817.88 (370.9) 997.62 (452.0) 257.1 281.5
F......................................... 584 (264.8) 584.6 (265.1) 256.2 289.3
G......................................... 191(86.6) 191.6 (86.9) 250.4 277.7
H......................................... 60.5 (24.7) 61.1 (27.7) 245.2 268.8
I......................................... 18.4 (8.3) 30.4 (13.8) 242.5 276.9
J......................................... 945 (428.6) 946.8 (429.4) 258.1 294.6
K......................................... Not available 350 (158.7) 253.4 291.5
L......................................... 624.52 (283.2) 627.12 (284.4) 256.2 290
M......................................... 324 (146.9) 324.9 (147.3) 253.2 283.6
N......................................... 219.92 (99.7) 238.08 (107.9) 252 285.3
O......................................... 72 (36.6) 104.64 (47.5) 248.3 281.2
P......................................... 90 (40.8) 130.8 (59.3) 249.3 281.2
Q......................................... 94 (42.6) 94.4 (42.8) 247.5 277.7
R......................................... 35.12 (15.9) 35.82 (16.2) 241.7 270.3
S......................................... 130 (58.9) 130 (58.9) 249.4 283
----------------------------------------------------------------------------------------------------------------
\a\ lbm = pound-mass.
Mission-Day Categories
The munitions proposed to be used by each military unit were
grouped into mission-day categories so the acoustic impact analysis
could be based on the total number of detonations conducted during a
given mission instead of each individual detonation. This analysis was
done to account for the accumulated energy from multiple detonations
over a 24-hour period.
The estimated number of mission days assigned to each category was
based on historical numbers and projections provided by certain user
groups. Although the mission-day categories may not represent the exact
manner in which munitions would be used, they provide a conservative
range of mission scenarios to account for accumulated energy from
multiple detonations. It is important to note that only acoustic energy
metrics (SEL) are affected by the accumulation of energy over a 24-hour
period. Pressure metrics (e.g., peak SPL and positive impulse) do not
accumulate and are based on the highest impulse pressure value within
the 24-hour period. Based on the categories developed, the total NEWi
per mission day would range from 2,413.6 to 30.4 lb (1,094.6 to 13.8
kg). The highest detonation energy of any single munition used under
the USAF's proposed activities would be 945 lb (428.5 kg) NEW, which
was also the highest NEW for a single munition in the previous LOA
Request. The munitions having this NEW include the GBU-10, GBU-24, and
GBU-31.
Note that the types of munitions that would be used for SINKEX
testing are controlled information and, therefore, not identified in
this LOA Request. For the purpose of analysis, SINKEX exercises are
assigned to mission-day category J, which represents a single
subsurface detonation of 945 lb NEW. SINKEX exercises would not exceed
this NEW. The 2 annual SINKEX exercises are added to the other 8 annual
missions involving subsurface detonations of these bombs, resulting in
10 total annual missions under mission-day category J.
As indicated in Table 25, a total of 19 mission-day categories (A
through S) were developed a part of this LOA application. The table
also contains information on the number of munitions per day, number of
mission days per year, annual quantity of munitions and the NEWi per
mission day.
Table 25--Mission-Day Categories for Acoustic Impact Analysis
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Mission-day Warhead NEW (lb)/ Detonation Munitions Mission days Annual NEWi per mission
User group category Munition type Category (kg) NEWi (lb)/kg scenario per day per year quantity day (lb)/(kg)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
53 WEG....................... A AGM-158D JASSM Missile........ 240.26 (108.9) 241.36 (109.4) Surface........ 4 1 4 2,413.6 (1,095.9)
XR.
AGM-158B JASSM Missile........ 240.26 (108.9) 241.36 (109.4) Surface........ 3 1 3 .................
ER.
AGM-158A JASSM.. Missile........ 240.26 (108.9) 241.36 (109.4) Surface........ 3 1 3 .................
B GBU-54 KMU-572C/ Bomb (Mk-82)... 192 (87.1) 192.3 (87.2) Surface........ 4 1 4 2,029.9 (920.5)
B.
GBU-54 KMU-572B/ Bomb (Mk-82)... 192 (87.1) 192.3 (87.2) Surface........ 4 1 4 .................
B.
AGM-65D......... Missile........ 85 (38.5) 98.3 (44.6) Surface........ 5 1 5 .................
C AGM-65H2........ Missile........ 85 (37.5) 98.3 (44.6) Surface........ 5 1 5 1,376.2 (624.1)
AGM-65G2........ Missile........ 85 (38.5) 98.3 (44.6) Surface........ 5 1 5 .................
AGM-65K2........ Missile........ 85 (38.5) 98.3 (44.6) Surface........ 4 1 4 .................
D AGM-65L......... Missile........ 85 (38.5) 98.3 (44.6) Surface........ 5 1 5 836.22 (379.2)
AIM-120C3....... Missile........ 15 (6.8) 36.18 (16.4) Surface........ 4 1 4 .................
AIM-9X Blk I.... Missile........ 7.7 (4.5) 20 (9.1) Surface........ 10 1 10 .................
E AGM-114 N-4D Missile........ 9 (4.1) 13.08 (5.9) Surface........ 4 1 4 997.62 (452.4)
with TM.
AGM-114 N-6D Missile........ 9 (4.1) 13.08 (5.9) Surface........ 4 1 4 .................
with TM.
[[Page 8174]]
AGM-179 JAGM.... Missile........ 9 (4.1) 13.08 (5.9) Surface........ 4 1 4 .................
AGM-114 R2 with Missile........ 9 (4.1) 13.08 (5.9) Surface........ 4 1 4 .................
TM (R10).
AGM-114 R-9E Missile........ 9 (4.1) 13.08 (5.9) Surface........ 4 1 4 .................
with TM (R11).
AGM-114Q with TM Missile........ 9 (4.1) 13.08 (5.9) Surface........ 4 1 4 .................
AGR-20 (APKWS).. Rocket......... 2.3 (1.0) 3.8 (1.7) Surface........ 12 1 12 .................
AGM-176......... Missile........ 9 (4.1) 13.08 (5.9) Surface........ 4 1 4 .................
PGU-43 (105 mm). Gun Ammunition. 4.7 (2.1) 4.72 (2.1) Surface........ 100 1 100 .................
GBU-69.......... Bomb........... 36 (16.3) 36.1 (13.3) Surface........ 2 1 2 .................
GBU-70.......... Bomb........... 36 (16.3) 36.1 (16.3) Surface........ 1 1 4 .................
AGM-88C w/FTS... Missile........ \a\ 0.70 (0.3) 0 Surface........ 2 1 2 .................
AGM-88B w/FTS... Missile........ \a\ 0.70 (0.3) 0 Surface........ 2 1 2 .................
AGM-88F w/FTS... Missile........ \a\ 0.70 (0.3) 0 Surface........ 2 1 2 .................
AGM-88G w/FTS... Missile........ \a\ 0.70 (0.3) 0 Surface........ 2 1 2 .................
GBU-39 SDB (GTV) Bomb........... \a\ 0.39 (0.2) 0.49 (0.2) Surface........ 4 1 4 .................
GBU-53/B (GTV).. Bomb........... \a\ 0.34 (0.2) 0.44 (0.2) Surface........ 8 1 8 .................
AFSOC........................ F GBU-12.......... Bomb (Mk-82)... 192 (87.1) 192.3 (87.2) Surface........ 2 15 30 584.6 (263.1)
Mk-81 (GP 250 Bomb........... 100 (45.3) 100 (45.3) Surface........ 2 15 30 .................
lb).
AFSOC........................ G 105 mm HE (FU).. Gun Ammunition. 4.7 (2.1) 4.72 (2.1) Surface........ 30 25 (daytime) 750 191.6 (86.8)
30 mm HE........ Gun Ammunition. 0.1 (0.1) 0.1 (0.01) Surface........ 500 12,500 .................
H 105 mm HE (TR).. Gun Ammunition. 0.35 (0.2) 0.37 (0.2) Surface........ 30 45 (nighttime) 1,350 61.1 (27.7)
30 mm HE........ Gun Ammunition. 0.1 (0.1) 0.1 (0.01) Surface........ 500 22,500 .................
I 2.75-inch Rocket Rocket......... 2.3 (1.0) 3.8 (1.7) Surface........ 8 50 400 30.4 (13.8)
(including
APKWS).
96 OG........................ J GBU-10, 24, or Bomb (Mk-84)... 945 (428.6) 946.8 (429.4) Subsurface..... 1 \b\ 10 \b\ 10 946.8 (429.4)
31 (QUICKSINK).
K HACM............ Hypersonic Not available 350 (158.7) Surface........ 1 1 2 350 (158.7)
Weapon.
L AGM-158 (JASSM). Missile........ 240.26 (108.9) 241.36 (109.4) Surface........ 2 1 2 627.12 (284.3)
GBU-39 (SDB I) Bomb........... 72 (32.6) 72.2 (32.7) Surface........ 2 1 2 .................
Simultaneous
Launch \c\.
M GBU-39 (SDB I).. Bomb........... 36 (16.3) 36.1 13.3) Surface........ 4 2 8 324.9 (147.3)
GBU-39 (LSDB)... Bomb........... 36 (16.3) 36.1 (16.3) Surface........ 5 2 10 .................
N GBU-39B/B LSDB.. Bomb........... 36 (16.3) 36.1 (16.3) Surface........ 2 1 2 238.08 (107.9)
Spike NLOS...... Missile........ 34.08 (15.4) 40 (18.1) Surface........ 3 1 3 .................
GBU-53 (SDB II). Bomb........... 22.84 (13.4) 22.94 (10.4) Surface........ 2 1 2 .................
O AGM-114R Missile........ 9 (4.1) 13.08 (5.9) Surface........ 8 4 36 104.64 (47.5)
Hellfire.
P AGM-114 Hellfire Missile........ 9 (4.1) 13.08 (5.9) Surface........ 5 2 10 130.8 (59.3)
AGM-176 Griffin. Missile........ 9 (4.1) 13.08 (5.9) Surface........ 5 2 10 .................
Q 105 mm HE (FU).. Gun Ammunition. 4.7 (2.1) 4.72 (2.1) Surface........ 20 3 60 94.4 (42.8)
R Inert GBU-39 Bomb........... 0.39 (0.2) 0.49 (0.2) Surface........ 4 1 4 35.82 (16.2)
(LSDB) with
live fuze.
Inert GBU-53 Bomb........... 0.34 (0.2) 0.44 (0.2) Surface........ 4 1 4 .................
(SDB II) with
live fuze.
105 mm HE (TR).. Gun Ammunition. 0.35 (0.2) 0.37 (0.2) Surface........ 60 1 60 .................
30 mm HE........ Gun Ammunition. 0.1 (0.1) 0.1 (0.01) Surface........ 99 1 99 .................
NAVSCOL EOD.................. S Underwater Mine Charge......... \d\ 20 (9.07) 20 (9.07) Subsurface..... 4 8 32 130 (58.9)
Charge.
Floating Mine Charge......... \d\ 5 (2.3) 5 (2.3) Surface........ 10 8 80 .................
Charge.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Warhead replaced by FTS/TM. Identified NEW is for the FTS.
\b\ Includes 2 SINKEX exercises.
\c\ NEW is doubled for simultaneous launch.
\d\ Estimated.
Marine Mammal Density
Densities of the common bottlenose dolphin, Atlantic spotted
dolphin, and Rice's whale in the study area are based on habitat-based
density models and spatial density models developed by the NOAA
Southeast Fisheries Science Center for the species in the Gulf of
Mexico (NOAA 2022). The density models, herein referred to as the NOAA
model, integrated visual observations from aerial and shipboard surveys
conducted in the Gulf of Mexico from 2003 to 2019.
The NOAA model was used to predict the average density of the
common bottlenose dolphin and Atlantic spotted dolphin in the existing
LIA and proposed East LIA. The model generates densities for hexagon-
shaped raster grids that are 40 square kilometers (km\2\). The average
annual density of each dolphin species in the existing LIA and proposed
East LIA was computed in a geographic information system (GIS) based on
the densities of the raster grids within the boundaries of each LIA. To
account for portions of the grids outside of the LIA, the species
density value of each grid was area-weighted based on the respective
area of the grid within the LIA. For example, the density of a grid
that is 70 percent within the LIA would be weighted to reflect only the
70 percent grid area, which contributes to the average density of the
entire LIA. The density of the 30 percent grid area outside the LIA
does not contribute to the average LIA density, so it is not included
in the estimation. The resulting area-weighted densities of all the
grids were summed to determine the average annual density of each
dolphin species
[…truncated; see source link]Indexed from Federal Register on February 7, 2023.
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