[Federal Register Volume 86, Number 134 (Friday, July 16, 2021)]
[Proposed Rules]
[Pages 37790-37852]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-14542]



[[Page 37789]]

Vol. 86

Friday,

No. 134

July 16, 2021

Part II





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 the U.S. Navy Training and Testing Activities in the Point Mugu Sea 
Range Study Area; Proposed Rule

  Federal Register / Vol. 86 , No. 134 / Friday, July 16, 2021 / 
Proposed Rules  

[[Page 37790]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 210701-0141]
RIN 0648-BK07


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to the U.S. Navy Training and Testing Activities in the 
Point Mugu Sea Range Study Area

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. Navy (Navy) to take 
marine mammals incidental to training and testing activities conducted 
in the Point Mugu Sea Range (PMSR) Study Area. 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 Navy 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 
Navy'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 August 
30, 2021.

ADDRESSES: Submit all electronic public comments via the Federal e-
Rulemaking Portal. Go to https://www.regulations.gov and enter NOAA-
NMFS-2021-0064 in the Search box. Click on the ``Comment'' icon, 
complete the required fields, and enter or attach your comments.
    Instructions: Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered by NMFS. All comments received are a part of the 
public record and will generally be posted for public viewing on 
www.regulations.gov without change. All personal identifying 
information (e.g., name, address), confidential business information, 
or otherwise sensitive information submitted voluntarily by the sender 
will be publicly accessible. NMFS will accept anonymous comments (enter 
``N/A'' in the required fields if you wish to remain anonymous). 
Attachments to electronic comments will be accepted in Microsoft Word, 
Excel, or Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT: Stephanie Egger, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems accessing these 
documents, or for anyone who is unable to comment via electronic 
submission, please call the contact listed above.

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 Navy's training and 
testing activities (which qualify as military readiness activities) 
from the use of at-surface and near-surface explosive detonations 
throughout the PMSR Study Area, as well as launch events from San 
Nicolas Island (SNI). The Study Area includes 36,000 square miles and 
is located adjacent to Los Angeles, Ventura, Santa Barbara, and San 
Luis Obispo Counties along the Pacific Coast of Southern California 
(see Figure 1.1 of the application). The two primary components of the 
PMSR are the Special Use Airspace (SUA) and the ocean Operating Areas 
(PMSR-controlled sea space). The PMSR-controlled sea space parallels 
the California coast for approximately 225 nautical miles (nmi) and 
extends approximately 180 nmi seaward (see Figure 1-1 of the 
application).
    NMFS received an application from the Navy requesting seven-year 
regulations and an authorization to incidentally take individuals of 
multiple species of marine mammals (``Navy's rulemaking/LOA 
application'' or ``Navy's application''). Take is anticipated to occur 
by Level A and Level B harassment incidental to the Navy'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 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

[[Page 37791]]

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 seven years. Prior to this 
amendment, all incidental take rules under section 101(a)(5)(A) were 
limited to five years.

Summary and Background of Request

    On March 9, 2020, NMFS received an application from the Navy for 
authorization to take marine mammals by Level A and Level B harassment 
incidental to training and testing activities (categorized as military 
readiness activities) from (1) the use of at-surface or near-surface 
explosive detonations in the PMSR Study Area, as well as (2) launch 
events from SNI, over a seven-year period beginning October 2021 
through October 2028. We received a revised application on August 28, 
2020, which provided minor revisions to the mitigation and monitoring 
sections, and upon which the Navy's rulemaking/LOA application was 
found to be adequate and complete. On September 4, 2020, we published a 
notice of receipt (NOR) of application in the Federal Register (85 FR 
55257), requesting comments and information related to the Navy's 
request for 30 days. We reviewed and considered all comments and 
information received on the NOR in development of this proposed rule.
    The following types of training and testing, which are classified 
as military readiness activities pursuant to the MMPA, as amended by 
the 2004 NDAA, will be covered under the regulations and LOA: Air 
warfare (air-to-air, surface-to-air), electronic warfare (directed 
energy--lasers and high-powered microwave systems), and surface warfare 
(surface-to-surface, air-to-surface, and subsurface-to surface). The 
proposed activities will not include any sonar, pile driving/removal, 
or use of air guns.
    The Navy's mission is to organize, train, equip, and maintain 
combat-ready naval forces capable of winning wars, deterring 
aggression, and maintaining freedom of the seas. This mission is 
mandated by Federal law (10 U.S.C. 8062), which requires the readiness 
of the naval forces of the United States. The Navy executes this 
responsibility by training and testing at sea, often in designated 
operating areas (OPAREA) and testing and training ranges. The Navy must 
be able to access and utilize these areas and associated sea space and 
air space in order to develop and maintain skills for conducting naval 
operations. The Navy's testing activities ensure naval forces are 
equipped with well-maintained systems that take advantage of the latest 
technological advances. The Navy's research and acquisition community 
conducts military readiness activities that involve testing. The Navy 
tests ships, aircraft, weapons, combat systems, sensors, and related 
equipment, and conducts scientific research activities to achieve and 
maintain military readiness.
    The Navy has been conducting testing and training activities in the 
PMSR Study Area since the PMSR was established in 1946. The tempo and 
types of training and testing activities fluctuate because of the 
introduction of new technologies, the evolving nature of international 
events, advances in warfighting doctrine and procedures, and changes in 
force structure (e.g., organization of ships, submarines, aircraft, 
weapons, and personnel). Such developments influence the frequency, 
duration, intensity, and location of required training and testing 
activities. The proposed activities include current activities, 
previously analyzed in the 2002 PMSR Environment Impact Statement/
Overseas Environmental Impact Statement (EIS/OEIS), and increases in 
the testing and training activities as described in the 2020 PMSR DEIS/
OEIS. NMFS promulgated MMPA incidental take regulations relating to 
missile launches from SNI from June 3, 2014, through June 3, 2019 (79 
FR 32678; June 6, 2014). Since then, the Navy has been operating under 
IHAs (84 FR 28462, June 19, 2019; 85 FR 38863, June 29, 2020) for those 
similar activities on SNI. For this rulemaking, the Navy is requesting 
authorization for marine mammal take incidental to activities on SNI 
similar to those they have conducted under these and previous 
authorizations, as well as the use of at-surface and near-surface 
explosive detonations throughout the PMSR Study Area. The proposed 
testing and training activities are deemed necessary to accomplish 
Naval Air System Command's mission of providing for the safe and secure 
collection of decision-quality data; and developing, operating, 
managing and sustaining the interoperability of the Major Range Test 
Facility Base at the PMSR into the foreseeable future.
    The Navy's rulemaking/LOA application reflects the most up-to-date 
compilation of training and testing activities deemed necessary to 
accomplish military readiness requirements. The types and numbers of 
activities included in the rule account for fluctuations in training 
and testing in order to meet evolving or emergent military readiness 
requirements. These proposed regulations would cover training and 
testing activities that would occur for a seven-year period beginning 
October 2021.

Description of the Specified Activity

    The Navy requests authorization to take marine mammals incidental 
to conducting training and testing activities. The Navy has determined 
that explosive stressors and missile launch activities are most likely 
to result in impacts on marine mammals that could rise to the level of 
harassment, and NMFS concurs with this determination. Descriptions of 
these activities are provided in section 2 of the 2020 PMSR Draft EIS/
OEIS (DEIS/OEIS) (U.S. Department of the Navy, 2020) and in the Navy's 
rulemaking/LOA application (https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities), and are summarized here.

Dates and Duration

    The specified activities would occur at any time during the seven-
year period of validity of the regulations, with the exception of the 
activity types and time periods for which limitations have explicitly 
been identified (to the maximum extent practicable; see Proposed 
Mitigation Measures section). The proposed amount of training and 
testing activities are described in the Detailed Description of the 
Specified Activities section (Table 3).

Geographical Region

    The PMSR Study Area is located adjacent to Los Angeles, Ventura, 
Santa Barbara, and San Luis Obispo Counties along the Pacific Coast of 
Southern California and includes a 36,000-square-mile sea range (Figure 
1). It is a designated Major Range Test Facility Base and is considered 
a national asset that exists primarily to provide test and evaluation 
information for DoD decision makers and to support the needs of weapon 
system development programs and DoD research needs. The two primary 
components of the PMSR Study Area are Special Use Airspace (SUA) and 
the ocean Operating Areas. Additionally, the Navy is proposing launch 
activities on San Nicolas Island (SNI), California, for testing and 
training activities associated with operations within the PMSR Study 
Area. SNI is one

[[Page 37792]]

of the Channel Islands in the PMSR Study Area.
Special Use Airspace
    The SUA is airspace designated wherein activities must be confined 
because of their nature, or wherein limitations are imposed upon 
aircraft operations that are not a part of those activities, or both. 
SUA consists of both controlled and uncontrolled airspace and has 
defined dimensions. Flight and other activities for non-participating 
aircraft are restricted or prohibited for safety or security reasons. 
The majority of SUA is established for military flight activities and, 
with the exception of prohibited areas, may be used for commercial or 
general aviation when not reserved for military activities. Two area 
components of the PMSR SUA:
    [ssquf] Warning Areas--A Warning Area is airspace of defined 
dimensions, extending from 3 nmi outward from the coast that contains 
activity that may be hazardous to non-participating aircraft. Warning 
areas are established to contain a variety of hazardous aircraft and 
non-aircraft activities, such as aerial gunnery, air and surface 
missile firings, bombing, aircraft carrier operations, surface and 
subsurface operations, and naval gunfire. The 11 Warning Areas within 
the PMSR include W-532N, W-532E, W-532S; W-537; W-289N, W-289 S, W-
289W, W-289E; W-292W, W-292E; and W-412 (see Figure 1).
    [ssquf] Restricted Areas--restricted areas are a type of SUA within 
which the flight of aircraft, while not wholly prohibited, is subject 
to restriction.
Ocean Operating Areas
    The PMSR-controlled sea space (Ocean Operating Areas) parallels the 
California coast for approximately 225 nmi and extends approximately 
180 nmi seaward, aligning with the PMSR Warning Area airspace (Figure 
1). The controlled sea space areas consist of the following:
    [ssquf] Surface Danger Zones--A danger zone is a defined water area 
used for target practice, bombing, rocket firing, or other especially 
hazardous military activities.
    [ssquf] Restricted Area--A restricted area is a defined water area 
for the purpose of prohibiting or limiting public access to the area.
    Additional detail can be found in Chapter 2 of the Navy's 
rulemaking/LOA application.
BILLING CODE 3510-22-P

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[GRAPHIC] [TIFF OMITTED] TP16JY21.002

BILLING CODE 3510-22-C

Overview of Training and Testing Within the PMSR Study Area

    The Navy describes and analyzes the effects of its activities 
within the 2020 PMSR DEIS/OEIS. In its assessment, the Navy concluded 
that at-surface and near-surface explosive detonations were the 
stressors that would result in impacts on marine mammals that could 
rise to the level of harassment as defined under the MMPA. Therefore, 
the Navy's rulemaking/LOA application provides the Navy's assessment of 
potential effects from these stressors in terms of various warfare 
mission areas in which they will be conducted.
Primary Mission Areas
    The Navy categorizes its at-sea activities into functional warfare 
areas called primary mission areas. Each warfare community may train in 
some or all of these primary mission areas. The Navy also categorizes 
most, but not all, of its testing activities under these primary 
mission areas. Activities addressed for the PMSR Study Area are 
categorized under three primary mission areas. Within those three 
primary mission areas, there are more specific categories or activity 
scenarios that reflect testing and training activities, as listed 
below: Air warfare (air-to-air, surface-to-air); Electronic warfare 
(directed energy--lasers and high-powered microwave systems); and 
Surface warfare (surface-to-surface, air-to-surface, and subsurface-to-
surface). A description of the munitions, targets, systems, and other 
material used during training and testing activities within these 
primary mission areas is provided in Appendix A (Training and Testing 
Activities Descriptions) of the 2020 PMSR DEIS/OEIS and summarized 
here.
    Air warfare--The mission of air warfare is to destroy or reduce 
enemy air and missile threats (including unmanned airborne threats) and 
serves two purposes: To protect U.S. forces from attacks from the air 
and to gain air superiority. Air warfare provides U.S. forces with 
adequate attack warnings, while denying hostile forces the ability to 
gather intelligence about U.S. forces.
    Aircraft conduct air warfare through radar search, detection, 
identification,

[[Page 37794]]

and engagement of airborne threats. Surface ships conduct air warfare 
through an array of modern anti-aircraft weapon systems such as 
aircraft-detecting radar, naval guns linked to radar-directed fire-
control systems, surface-to-air missile systems, and radar-controlled 
guns for close-in point defense.
    Testing of air warfare systems is required to ensure the equipment 
is fully functional under the conditions in which it will be used. 
Tests may be conducted on radar and other early-warning detection and 
tracking systems, new guns or gun rounds, and missiles. Testing of 
these systems may be conducted on new ships and aircraft, and on 
existing ships and aircraft following maintenance, repair, or 
modification. For some systems, tests are conducted periodically to 
assess operability. Additionally, tests may be conducted in support of 
scientific research to assess new and emerging technologies. Air-to-air 
scenarios involve the employment of an airborne weapon system against 
airborne targets. Missiles are fired from a fighter aircraft for both 
testing and training events. Surface-to-air scenarios evaluate the 
overall weapon system performance, warhead effectiveness, and software/
hardware modifications or upgrades of ground-based and ship-based 
weapons systems. Missiles are fired from a ship or a land-based 
launcher against a variety of supersonic and subsonic airborne targets.
    Electronic Warfare--The mission of electronic warfare is to degrade 
the enemy's ability to use electronic systems, such as communication 
systems and radar, and to confuse or deny them the ability to defend 
their forces and assets. Electronic warfare is also used to detect 
enemy threats and counter their attempts to degrade the electronic 
capabilities of the Navy. Typical electronic warfare activities include 
threat avoidance training, signals analysis for intelligence purposes, 
and use of airborne and surface electronic jamming devices (that block 
or interfere with other devices) to defeat tracking, navigation, and 
communications systems. Testing of electronic warfare systems is 
conducted to improve the capabilities of systems and ensure 
compatibility with new systems. Testing involves the use of aircraft, 
surface ships, and submarine crews to evaluate the effectiveness of 
electronic systems. Similar to training activities, typical electronic 
warfare testing activities include the use of airborne and surface 
electronic jamming devices (including testing chaff and flares; see 
Appendix A (PMSR Scenario Descriptions) of the 2020 PMSR DEIS/OEIS for 
a description of these devices) to defeat tracking and communications 
systems.
    Surface Warfare--The mission of surface warfare is to obtain 
control of sea space from which naval forces may operate, and entails 
offensive action against other surface, subsurface, and air targets 
while also defending against enemy forces. In surface warfare, aircraft 
use guns, air-launched cruise missiles, or other precision-guided 
munitions; ships employ naval guns, and surface-to-surface missiles; 
and submarines attack surface ships using submarine-launched, anti-ship 
cruise missiles. Surface warfare training includes surface-to-surface 
gunnery and missile exercises, air-to-surface gunnery and missile 
exercises, and submarine missile launch activities, and other munitions 
against surface targets. Testing of weapons used in surface warfare is 
conducted to develop new technologies and to assess weapon performance 
and operability with new systems, such as unmanned systems. Tests 
include various air-to-surface guns and missiles, surface-to-surface 
guns and missiles, and bombing tests. Testing activities may be 
integrated into training activities to test aircraft or aircraft 
systems in the delivery of munitions on a surface target. In most cases 
the tested systems are used in the same manner in which they are used 
for Fleet training activities. Air-to-surface tests evaluate the 
integration of a missile or other weapons system into Department of 
Defense aircraft, or the performance of the missile/system itself. 
Missiles are fired from an aircraft against a variety of mobile 
seaborne targets and fixed aim points.
    Summary Testing--Research, Development, Acquisition, Testing, and 
Evaluation of new technologies by the U.S. Department of Defense occurs 
continually to ensure that the U.S. military can counter new and 
anticipated threats. All new Navy systems and related equipment must be 
tested to ensure proper functioning before delivery to the Fleets for 
use. The PMSR Study Area is the Navy's primary ocean testing area for 
guided missiles and related ordnance. Test operations on the PMSR Study 
Area are conducted under highly controlled conditions, allowing for the 
collection of empirical data to evaluate the performance of a weapon 
system or subsystem. Testing conducted in the PMSR Study Area is 
important for maintaining readiness. Two of the U.S. Navy's Systems 
Commands, Naval Sea Systems Command (NAVSEA) and Naval Air Systems 
Command (NAVAIR), sponsor the majority of the testing within the PMSR 
Study Area. NAVSEA's five affiliated Program Executive Offices (PEOs) 
oversee over a dozen Program Manager, Sea offices that sponsor testing 
activities within the PMSR Study Area. NAVAIR's four affiliated PEOs, 
along with NAVAIR Headquarters-managed programs, oversee approximately 
20 Program Managers and Air offices that also sponsor testing 
activities at PMSR.
    Target and Missile Launches on SNI--The Navy plans to continue a 
target and missile launch program from two launch sites on SNI for 
testing and training activities associated with operations within the 
PMSR Study Area. Missiles vary from tactical and developmental weapons 
to target missiles used to test defensive strategies and other weapons 
systems. Some launch events involve a single missile or target, while 
others involve the launch of multiple missiles or targets in quick 
succession. The missiles or targets are launched from one of several 
fixed locations on the western end of SNI. Missiles or targets launched 
from SNI fly generally west, southwest, and northwest through the PMSR 
Study Area. The primary launch locations are the Alpha Launch Complex, 
located 190 meters (m) above sea level on the west-central part of SNI 
and the Building 807 Launch Complex, which accommodates several fixed 
and mobile launchers, at the western end of SNI at approximately 11 m 
above sea level. The Point Mugu airfield on the mainland, the airfield 
on SNI, and the target sites in the PMSR will be a routine part of 
launch operations.

Description of Stressors

    The Navy uses a variety of platforms, weapons, and other devices, 
including ones used to ensure the safety of Sailors and Marines, to 
meet its mission. Training and testing with these systems may introduce 
acoustic (sound) energy or shock waves from explosives into the 
environment. The following subsections describe explosives detonated at 
or near the surface of the water and launch noise associated with 
missiles launched from SNI for marine mammals and their habitat 
(including prey species) within the PMSR Study Area. Because of the 
complexity of analyzing sound propagation in the ocean environment, the 
Navy relied on acoustic models in its environmental analyses and 
rulemaking/LOA application that considered sound source characteristics 
and varying ocean conditions across the PMSR Study Area. Stressor/
resource interactions that were determined to have de minimis or no 
impacts (i.e., vessel, aircraft, or weapons noise) were

[[Page 37795]]

not carried forward for analysis in the Navy's rulemaking/LOA 
application. NMFS reviewed the Navy's analysis and conclusions on de 
minimis sources and finds them complete and supportable.
    Acoustic stressors include incidental sources of broadband sound 
produced as a byproduct of vessel movement and use of weapons or other 
deployed objects. Explosives also produce broadband sound but are 
characterized separately from other acoustic sources due to their 
unique hazardous characteristics. There are no sonar activities 
proposed in the PMSR Study Area. Characteristics of explosives are 
described below.
    In order to better organize and facilitate the analysis of various 
explosives used for training and testing by the Navy, including sonar 
and other transducers and explosives, a series of source 
classifications, or source bins, was developed by the Navy. The source 
classification bins do not include the broadband sounds produced 
incidental to vessel or aircraft transits, weapons firing, and bow 
shocks.
    The use of source classification bins provides the following 
benefits:
    [ssquf] Provides the ability for new sensors or munitions to be 
covered under existing authorizations, as long as those sources fall 
within the parameters of a bin;
    [ssquf] Improves efficiency of source utilization data collection 
and reporting requirements anticipated under the MMPA authorizations;
    [ssquf] Ensures a conservative approach to all impact estimates, as 
all sources within a given class are modeled as the most impactful 
source (having the largest net explosive weight) within that bin;
    [ssquf] Allows analyses to be conducted in a more efficient manner, 
without any compromise of analytical results; and
    [ssquf] Provides a framework to support the reallocation of source 
usage (number of explosives) between different source bins, as long as 
the total numbers of takes remain within the overall analyzed and 
authorized limits. This flexibility is required to support evolving 
Navy training and testing requirements, which are linked to real world 
events.
Explosives
    This section describes the characteristics of explosions during 
naval training and testing. The activities analyzed in the Navy's 
rulemaking/LOA application that use explosives are described in 
Appendix A (PMSR Scenario Descriptions) of the 2020 PMSR DEIS/OEIS.
    To more completely analyze the results predicted by the Navy's 
acoustic effects model from detonations occurring in-air above the 
ocean surface, it is necessary to consider the transfer of energy 
across the air-water interface.
    Detonation of an explosive in air creates a supersonic high 
pressure shock wave that expands outward from the point of detonation 
(Kinney & Graham, 1985; Swisdak, 1975). The near-instantaneous rise 
from ambient pressure to an extremely high peak pressure is what makes 
the explosive shock wave potentially injurious to an animal 
experiencing the rapid pressure change (U.S. Department of the Navy, 
2017e). Farther from an explosive, the peak pressures decay and the 
explosive waves propagate as an impulsive, broadband sound. As the 
shock wave-front travels away from the point of detonation, it slows 
and begins to behave as an acoustic wave-front travelling at the speed 
of sound. Whereas a shock wave from a detonation in-air has an abrupt 
peak pressure, that same pressure disturbance when transmitted through 
the water surface results in an underwater pressure wave that begins 
and ends more gradually compared with the in-air shock wave, and 
diminishes with increasing depth and distance from the source (Bolghasi 
et al., 2017; Chapman and Godin, 2004; Cheng and Edwards, 2003; Moody, 
2006; Richardson et al., 1995; Sawyers, 1968; Sohn et al., 2000; 
Swisdak, 1975; Waters and Glass, 1970; Woods et al., 2015). The 
propagation of the shock wave in air and then transitioning underwater, 
is very different from a detonation occurring deep underwater where 
there is little interaction with the surface. In the case of an 
underwater detonation occurring just below the surface, a portion of 
the energy from the detonation would be released into the air (referred 
to as surface blow off), and at greater depths a pulsating, air-filled 
cavitation bubble would form, collapse, and reform around the 
detonation point (Urick, 1983). The Navy's acoustic effects model for 
analyzing underwater impacts on marine species does not account for the 
loss of energy due to surface blow-off or cavitation at depth. Both of 
these phenomena would diminish the magnitude of the acoustic energy 
received by an animal under real-world conditions (U.S. Department of 
the Navy, 2018c).
    Propagation of explosive pressure waves in water is highly 
dependent on environmental characteristics such as bathymetry, bottom 
type, water depth, temperature, and salinity, which affect how the 
pressure waves are reflected, refracted, or scattered; the potential 
for reverberation; and interference due to multi-path propagation. In 
addition, absorption greatly affects the distance over which higher-
frequency components of explosive broadband noise can propagate. 
Because of the complexity of analyzing sound propagation in the ocean 
environment, the Navy relies on acoustic models in its environmental 
analyses that consider sound source characteristics and varying ocean 
conditions across the PMSR Study Area (U.S. Department of the Navy, 
2019a).
    Missiles, rockets, bombs, and medium and large-caliber projectiles 
may be explosive or nonexplosive, depending on the objective of the 
testing or training activity in which they are used. The proposed 
activities do not include explosive munitions used underwater. 
Missiles, bombs, and projectiles that detonate at or near (within 10 m 
of) the water's surface are considered for the potential impact they 
may have on marine mammals. All explosives used during testing and 
training activities within the PMSR Study Area would detonate at or 
near the surface or in-air. Several parameters influence the acoustic 
effect of an explosive: The weight of the explosive warhead, the type 
of explosive material, the boundaries and characteristics of the 
propagation medium(s); and the detonation depth underwater and the 
depth of the receiver (i.e., marine mammal). The net explosive weight 
(NEW), which is the explosive power of a charge expressed as the 
equivalent weight of trinitrotoluene (TNT), accounts for the first two 
parameters.
Land-Based Launch Noise on San Nicolas Island
    Noise from target and missile launches on SNI can also occur. These 
ongoing activities affecting pinnipeds hauled out in the vicinity of 
launch sites have been analyzed previously (NMFS 2014, 2019, 2020) and 
are summarized below as part of the Navy's rulemaking/LOA application. 
As part of previous authorizations, the Navy could conduct up to 40 
launch events annually from SNI, but the total may be less than 40 
depending on operational requirements. Launch timing will be determined 
by operational, meteorological, and logistical factors. Up to 10 of the 
40 launches may occur at night, but this is also dependent on 
operational requirements, and night-time launches are only conducted 
when required by test objectives.

[[Page 37796]]

Vessel Strike
    Vessel strikes have the potential to result in incidental take from 
serious injury and/or mortality. Vessel strikes are not specific to any 
particular training or testing activity, but rather are a limited, 
sporadic, and incidental result of Navy vessel movement within a study 
area. Vessel strikes from commercial, recreational, and military 
vessels are known to seriously injure and occasionally kill cetaceans 
(Abramson et al., 2011; Berman-Kowalewski et al., 2010; Calambokidis, 
2012; Douglas et al., 2008; Laggner, 2009; Lammers et al., 2003; Van 
der Hoop et al., 2012; Van der Hoop et al., 2013), although reviews of 
the literature on ship strikes mainly involve collisions between 
commercial vessels and whales (Jensen and Silber, 2003; Laist et al., 
2001). Vessel speed, size, and mass are all important factors in 
determining both the potential likelihood and impacts of a vessel 
strike to marine mammals (Conn and Silber, 2013; Gende et al., 2011; 
Silber et al., 2010; Vanderlaan and Taggart, 2007; Wiley et al., 2016). 
For large vessels, speed and angle of approach can influence the 
severity of a strike.
    The number of Navy vessels in the PMSR Study Area at any given time 
varies and is dependent on scheduled testing and training requirements. 
Most activities include either one or two vessels and may last from a 
few hours to two weeks. Vessel movement as part of the proposed 
activities would be widely dispersed throughout the PMSR Study Area. 
Vessels used include ships (e.g., aircraft carriers, surface 
combatants), support craft, and submarines. Vessel size ranges from 15 
ft to over 1,000 ft, and vessels transit at speeds that are optimal for 
fuel conservation or to meet operational requirements. In comparison, 
commercial ship size can range from very large oil tankers that are 
over 1,000 ft in length to the smaller general cargo ships with lengths 
that can be under 300 ft. Large Navy ships (greater than 18 m in 
length) generally operate at average speeds of 10-15 knots, and 
submarines generally operate at speeds in the range of 8-13 knots. 
Small Navy craft (for purposes of this discussion, less than 18 m in 
length), which are all support craft, have much more variable speeds 
(0-50+ knots, dependent on the mission). While these speeds are 
averages that are representative of most events, some vessels need to 
operate outside of these parameters. For example, to produce the 
required relative wind speed over the flight deck, an aircraft carrier 
engaged in flight operations must adjust its speed through the water 
accordingly. Also, there are other instances, such as launch and 
recovery of a small rigid-hull inflatable boat, or retrieval of a 
target when vessels would be dead in the water, or moving slowly ahead 
to maintain steerage. There are a few specific testing and training 
events that include high-speed requirements for certain systems for 
which vessels would operate at higher speeds.
    Refer to Chapter 3, Affected Environment and Environmental 
Consequences of the 2020 PMSR DEIS/OEIS for additional details on 
vessel use and movement in the PMSR Study Area.

Detailed Description of the Specified Activities

Proposed Training and Testing Activities

    Training and testing activities would be conducted at sea, in 
designated airspace, and on SNI, within the PMSR Study Area.
    The proposed training and testing activities are deemed necessary 
to accomplish Naval Air Systems Command's mission of providing for the 
safe and secure collection of decision-quality data; and developing, 
operating, managing and sustaining the interoperability of the Major 
Range Test Facility Base at the PMSR into the foreseeable future. 
Collectively, the proposed training and testing activities support 
current and projected military readiness requirements into the 
foreseeable future, as shown in Table 1.

 Table 1--Maximum Number of Annual Proposed Activities in the PMSR Study
                                  Area
                       [Inclusive of SNI launches]
------------------------------------------------------------------------
                                                             Proposed
            Activity              Activity sub category     activities
------------------------------------------------------------------------
Aerial Targets (# of targets)..  .......................             176
Surface Targets (# of targets).  .......................             522
Ordnance (# of ordnance).......  Bombs..................              30
                                 Gun Ammunition.........         281,230
                                 Missiles...............             584
                                 Rockets................              40
------------------------------------------------------------------------

    Most of the factors influencing frequency and types of activities 
are fluid in nature (i.e., continually evolving and changing), and the 
annual activity level in the PMSR Study Area will continue to 
fluctuate. The number of events may not be the same year to year, but 
the maximum number of events were predicted annually. Total annual 
events would not exceed what is proposed in Table 1 above. Proposed 
training and testing duration and frequency varies depending on Fleet 
requirements, and funding and does not occur on a predictable annual 
cycle.
    Fleet training activities occur over scheduled continuous and 
uninterrupted blocks of time, focusing on the development of core 
capabilities/skills. Training events in the PMSR Study Area are 
conducted to ensure Navy forces can sustain their training cycle 
requirements. Primarily, changes occur with increases or decreases in 
annual operational tempo of activities, in addition to changes in the 
types of aircraft, vessels, targets, ordnance, and tasks that are 
actions or processes performed as part of Navy operations.
    Future testing depends on scientific and technological developments 
that are not easy to predict, and experimental designs may evolve with 
emerging science and technology. Even with these challenges, the Navy 
makes every effort to forecast all future testing requirements. As a 
result, testing requirements are driven by the need to support Fleet 
readiness based on emerging national security interests, and 
alternatives must have sufficient annual capacity to conduct the 
research, development, and testing of new systems and technologies, 
with upgrades, repairs, and maintenance of existing systems.
Fleet Training
    Fleet training within the PMSR Study Area includes the same types 
of warfare of the primary mission areas. Training conducted in 
conjunction with testing activities provide Fleet operators unique 
opportunities to train with ship and

[[Page 37797]]

aircraft combat weapon systems and personnel in scripted warfare 
environments, including live-fire events. For example, Fleet training 
would occur while testing a weapon system, in which Sailors would 
experience (be trained in) the use of the system being tested. Combat 
ship crews train in conjunction with scheduled ship testing and 
qualification trials, to take advantage of the opportunity to provide 
concurrent training and familiarization for ship personnel in 
maintaining and operating installed equipment, identifying design 
problems, and determining deficiencies in support elements (e.g., 
documentation, logistics, test equipment, or training). Live and inert 
weapons, along with chaff, flares, jammers, and lasers may be used.
    Typically concurrent with testing, surface training available 
within the PMSR Study Area includes tracking events, missile-firing 
events, gun-firing events, high-speed anti-radiation missile events, 
and shipboard self-defense system training, (e.g., Phalanx (Close-in 
Weapons System), Rolling Airframe Missile, and Evolved Sea Sparrow 
Missile). These events are limited in scope and generally focus on one 
or two tasks. Missiles may be fired against subsonic, supersonic, and 
hypersonic targets. Certain training events designed for single ships 
are conducted to utilize unique targets only available for training in 
the PMSR Study Area.
    Aviation warfare training conducted in the PMSR Study Area, 
categorized as unit-level training, is designed for a small number of 
aircraft up to a squadron of aircraft. These training events occur 
within the PMSR Study Area, as it is the only West Coast Navy venue to 
provide powered air-to-air targets. They are limited in scope and 
generally focus on one or two tasks. These scenarios require planning 
and coordination to ensure safe and effective training.
Combat Systems Testing
    The System Command Program Executive Offices are tasked with 
conducting extensive combat systems tests and trials on each new 
platform prior to releasing the platform to the Fleet, to include ships 
that have been in an extended upgrade or overhaul status. The PMSR 
Study Area is the preferred site to conduct these tests, as it offers a 
venue for a thorough evaluation of combat and weapons system 
performance through the actual employment of weapon systems. The 
comprehensive tests are conducted by the responsible Program Manager, 
with close cooperation from the Fleet Type Commanders (Surface Force, 
Air Force, or Submarine Force). Frequent tests conducted in the PMSR 
Study Area are Combat Systems Ship Qualification Trials (CSSQTs). This 
is a series of comprehensive tests and trials designed to show that the 
equipment and systems included in the CSSQT program meet combat system 
requirements. Live and inert weapons, along with chaff, flares, 
jammers, and lasers may be used. Naval Sea Systems Command has recently 
developed two new reporting programs to test and evaluate combat and 
weapons system performance on new classes of ships, resulting in an 
increased tempo in the PMSR Study Area.
Explosives At-Surface or Near the Surface
    Missiles, bombs, and projectiles that detonate at or near (within 
10 m of) the water's surface are considered for the potential that they 
could result in an acoustic impact to marine mammals that may be 
underwater and nearby. The maximum number of explosives and the 
appropriate events modeling bin for the proposed activities are 
provided in Table 2 for the proposed activities in the PMSR Study Area. 
Table 2 describes the maximum number of explosives that could be used 
in any year under the proposed training and testing activities. Under 
the proposed activities, bin use could vary annually (but would not 
exceed the maximum), and the seven-year totals for the proposed 
training and testing activities take into account that annual 
variability.

 Table 2--Explosives Detonating at or Near the Surface by Bins Annually and for a Seven-Year Period for Training
                                and Testing Activities Within the PMSR Study Area
                                           [Inclusive of SNI Launches]
----------------------------------------------------------------------------------------------------------------
                                                                                                  Maximum number
                                                                                  Maximum number      of high
                                                                                      of high       explosives
   Primary mission area activity         Explosive bin         Munition type         explosive    used over a 7-
             scenarios                                                            munitions used    year period
                                                                                     annually        proposed
                                                                                                     activity
----------------------------------------------------------------------------------------------------------------
Surface-Surface....................  E1                    Gunnery..............          22,110         154,770
                                     E3                    Gunnery..............           4,909          34,363
                                     E5                    Gunnery..............           1,666          11,662
Air-Surface........................  E5                    Rockets..............              24             168
Air-Surface; Surface-Air...........  E6                    Missiles.............              72             504
Air-Surface........................  E7                    Missiles, Bombs......              45             315
Air-Surface; Surface-Air...........  E8                    Missiles.............              45             315
Air-Surface; Surface-Surface.......  E9                    Missiles, Bombs,                   58             406
                                                            Rockets.
Surface-Surface; Subsurface-Surface  E10                   Missiles.............              13              91
----------------------------------------------------------------------------------------------------------------
Note: Bins E1-E5 are gunnery events that involve guns with high rates of firing ``clusters'' of munitions (e.g.,
  >80-200 rounds per minute for Bin E1, 500-650 rounds per minute for Bin E3, and 16-20 rounds per minutes for
  Bin E5), hence the high number of HE munitions used during these activities. The numbers above do not reflect
  the actual number of events, which can vary and typically last 1-3 hrs. The increase in tempo under the
  Proposed Action is a result of a proposed increase in Combat Systems Ship Qualification Trials as discussed in
  Section 2.2.1 (Current and Proposed Activities) of the 2020 PMSR DSEIS/OEIS.

    The explosive energy released by detonations in air has been well 
studied, and basic methods are available to estimate the explosive 
energy exposure with distance from the detonation (e.g., U.S. 
Department of the Navy, 1975). In air, the propagation of impulsive 
noise from an explosion is highly influenced by atmospheric conditions, 
including temperature and wind. While basic estimation methods do not 
consider the unique environmental conditions that

[[Page 37798]]

may be present on a given day, they allow for approximation of 
explosive energy propagation under neutral atmospheric conditions. 
Explosions that occur during air warfare would typically be at a 
sufficient altitude that a large portion of the sound refracts upward 
due to cooling temperatures with increased altitude. Based on an 
understanding of the explosive energy released by detonations in air, 
detonations occurring in air at altitudes greater than 10 m are not 
likely to result in acoustic impacts to marine mammals and thus are not 
carried forward in the analysis.
Missile Launch Activities on SNI
    Missiles can be propelled by either liquid-fueled or solid-fueled 
rocket engines; however, solid fuel is preferred for military uses. 
Such engines commonly propel tactical guided missiles (i.e., missiles 
intended for use within the immediate area) toward their targets at 
twice the speed of sound. Cruise or ballistic missiles are designed to 
strike targets far beyond the immediate area, and are therefore also 
known as strategic missiles. Cruise missiles are jet-propelled at 
subsonic speeds throughout their flights, while ballistic missiles are 
rocket-powered only in the initial (boost) phase of flight, after which 
they follow an arcing trajectory to the target. As gravity pulls the 
ballistic warhead back to Earth, speeds of several times the speed of 
sound are reached. Ballistic missiles are most often categorized as 
short-range, medium-range, intermediate-range, and intercontinental 
ballistic missiles. Missile weights range between 54-2,900 kilograms 
(kg), but total weight is dependent on fuel or boosters.
    Table 3 shows the number of launches that have occurred at SNI 
since 2001 and the number of launch events that have occurred during 
the associated comprehensive reporting timeframes. There have not been 
more than 25 launch events conducted in any given year since 2001. 
However, as part of the proposed activities, 40 launch events per year 
from SNI involving various missiles and aerial targets are requested 
for take authorization.

 Table 3--The Total Number of Launches That Have Occurred Since 2001 at
                                   SNI
------------------------------------------------------------------------
                                                             Number of
                       Time period                           launches
------------------------------------------------------------------------
August 2001 to March 2008...............................              77
June 2009 to June 2014..................................              36
June 2014 to June 2019..................................              27
------------------------------------------------------------------------

    A combination of missiles and targets are launched from SNI, 
including aerial targets, surface-to-surface missiles, and surface-to-
air missiles, with aerial targets representing the majority of the 
launches from SNI.
    The following descriptions are representative of some of the types 
of targets and missiles typically launched from SNI. While this list is 
not inclusive of all potential missiles and targets that could be 
launched annually, the descriptions and the sound profiles are 
representative of the diversity of the types of missiles and targets 
typically launched. For information on the sound levels these missiles 
produce please refer to Section 1.2 of the application.
    GQM-163A ``Coyote''--The Coyote, designated GQM-163A, is an 
expendable Supersonic Sea-Skimming Target (SSST) powered by a ducted-
rocket ramjet. This missile is designed to provide a ground-launched, 
aerial target system to simulate a supersonic, sea-skimming Anti-Ship 
Cruise missile threat. Coyote launches are expected to be the primary 
large missile launched from SNI over the next several years. Coyotes 
are launched from previously installed launchers at the inland location 
(Alpha Launch Complex) on SNI.
    Standard Missile (SM-2, SM-3, SM-6)--The Standard family of 
missiles consists of a range of air defense missiles including 
supersonic, medium, and extended range surface-to-air and surface-to-
surface missiles. The Standard Missile 3 Block IIA (SM-3) is a ship-
based missile system used to intercept short- to intermediate-range 
ballistic missiles as a part of the Aegis Ballistic Missile Defense 
System. Although primarily designed as an antiballistic missile 
defensive weapon, the SM-3 has also been employed in an anti-satellite 
capacity against a satellite at the lower end of low Earth orbit. 
Similarly, the SM-6 is a vertically launched, extended range missile 
compatible with the Aegis Weapon System to be used against extended 
range threats. The SM-6 Block I/IA combines the tested legacy of the 
SM-2 propulsion system and warhead with an active radio frequency 
seeker modified from the AIM-120 Advanced Medium Range Air-to-Air 
Missile. The new features allow for over-the-horizon engagements, 
enhanced capability at extended ranges and increased firepower. To 
date, only the SM-3 has been launched from SNI.
    Other Missiles That May Be Used During Launch Events--The Navy may 
also launch other missiles to simulate various types of threat missiles 
and aircraft and to test other systems. For example, Tactical Tomahawks 
were launched from Building 807 Launch Complex in 2018 and 2019. Under 
this proposed rule, missiles launched from SNI would have sound source 
levels the same or lower than missiles described above or previously 
launched from the island.

Vessel Movement

    The number and type of scheduled Navy vessels or Navy support 
vessels operating within the PMSR Study Area depends on the 
requirements for mission-essential activities, such as the test and 
evaluation of new weapon systems or qualification trials for upgraded 
existing ships. The types of Navy vessels or Navy support vessels 
operating within the PMSR are highly variable and range from small work 
boats used for nearshore work to major Navy combatants, up to and 
including aircraft carriers. Navy activities are conducted in large 
subdivisions of the total PMSR Study Area, and blocks of range times 
are allocated based on activity requirements. Most activities include 
either one or two vessels and may last from a few hours to two weeks. 
Vessel movement as part of the proposed activities would be widely 
dispersed throughout the PMSR Study Area.
    The PMSR Study Area military vessel activity can be divided into 
two categories: Project ships and support boats. Project ships are 
larger Navy combatant vessels, such as destroyers, cruisers, or any 
other commissioned Navy or foreign military ship directly involved in 
events. They may operate anywhere within the PMSR Study Area depending 
on activity needs, although most ship operations occur within 60 
nautical miles (nmi) of SNI. Most project ships and scheduled training 
ships operating in the PMSR Study Area transit there from off-range 
(e.g., San Diego). Support boats are smaller vessels directly involved 
in test activities and operate from the Port Hueneme Harbor. While they 
may also operate throughout the PMSR Study Area, support boat 
operations occur mainly within the range areas receiving the most use. 
Smaller support boats have limited range and usually operate close to 
shore near Point Mugu and SNI. The activity level of ships or boats is 
characterized by a ship or boat event.
    The Navy tabulated annual at-sea vessel steaming days for training 
and testing activities projected for the PMSR Study Area. Approximately 
333 annual events of Navy at-sea vessel usage will occur over 2,085 
hours (approximately 87 at-sea days) in the PMSR Study Area (Table 4). 
In comparison to the Southern

[[Page 37799]]

California portion (SOCAL) of the Hawaii-Southern California Training 
and Testing (HSTT) Study Area, the estimated number of annual at-sea 
days in the PMSR Study Area is less than 3 percent of what occurs in 
SOCAL annually.

  Table 4--Annual At-Sea Vessel Steaming Days for Training and Testing Activities Projected for the PMSR Study
                                                      Area
----------------------------------------------------------------------------------------------------------------
                                                                                         Proposed activity
                   Vessel                                 Ship type              -------------------------------
                                                                                      Events           Hours
----------------------------------------------------------------------------------------------------------------
CG.........................................  Guided Missile Cruiser.............              41             275
DDG-51.....................................  Guided Missile Destroyer...........              36             132
LHA........................................  Amphibious Assault Ship............              40             200
SDTS.......................................  Self-Defense Test Ship.............              50             190
WMSL-751/OPC...............................  Coast Guard Cutter.................               6              28
LCS Variant (LCS 1)........................  Littoral Combat Ship...............              40             360
LCS Variant (LCS 2)........................                                                   40             360
FF.........................................  Future Frigate.....................              40             360
DDG 1000 Zumwalt Class.....................  Guided Missile Destroyer...........               3              30
LHD........................................  Amphibious Assault Ship............               4              13
LPD........................................  Amphibious Transport Deck..........               4              13
LSD........................................  Dock Landing Ship..................               4              13
CVN........................................  Nuclear-Powered Aircraft Carrier...               6              16
SSBN.......................................  Ballistic Missile Submarine........              19              95
                                                                                 -------------------------------
    Total..................................                                                  333           2,085
----------------------------------------------------------------------------------------------------------------

    Additional details on Navy at-sea vessel movement are provided in 
the 2020 PMSR DEIS/OEIS.

Standard Operating Procedures

    For training and testing to be effective, personnel must be able to 
safely use their sensors and weapon systems as they are intended to be 
used in military missions and combat operations and to their optimum 
capabilities. Navy publishes or broadcasts standard operating 
procedures via numerous naval instructions and manuals, including but 
not limited to the following:
     Ship, submarine, and aircraft safety manuals;
     Ship, submarine, and aircraft standard operating manuals;
     Fleet Area Control and Surveillance Facility range 
operating instructions;
     Fleet exercise publications and instruction;
     Naval Air Warfare Center Weapons Division (NAWCWD) and 
Naval Sea Systems Command test range safety and standard operating 
instructions;
     Navy instrumented range operating procedures;
     Naval shipyard sea trial agendas;
     Research, development, test, and evaluation plans;
     Naval gunfire safety instructions;
     Navy planned maintenance system instructions and 
requirements;
     Federal Aviation Administration regulations;
     International Regulations for Preventing Collisions at 
Sea;
     Range safety standard operating procedures and 
instructions for explosive munitions; and
     Ammunition and Explosive Operations standard operating 
procedures.
    Because standard operating procedures are essential to safety and 
mission success, the Navy considers them to be part of the proposed 
Specified Activities, and has included them in the environmental 
analysis (see Chapter 3, Affected Environment and Environmental 
Consequences, of the 2020 PMSR DSEIS/OEIS for further details).

Description of Marine Mammals and Their Habitat in the Area of the 
Specified Activities

    Marine mammal species that have the potential to occur in the PMSR 
Study Area are presented in Table 5 along with an abundance estimate, 
an associated coefficient of variation value, and best and minimum 
abundance estimates. The Navy requests authorization to take 
individuals of marine mammal species by Level A and Level B harassment 
incidental to training and testing activities from detonations of 
explosives occurring at or near the surface and launch activities on 
SNI (Table 5).
    Information on the status, distribution, abundance, population 
trends, habitat, and ecology of marine mammals in the PSMR Study Area 
also may be found in Section 4 of the Navy's rulemaking/LOA 
application. NMFS reviewed this information and found it to be accurate 
and complete. Additional information on the general biology and ecology 
of marine mammals is included in the 2020 PMSR DEIS/OEIS. Table 5 
incorporates data from the U.S. Pacific and the Alaska Marine Mammal 
Stock Assessment Reports (SARs; Carretta et al., 2019; Muto et al., 
2019) and the most recent revised data in the draft SARs (see https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports). Table 5 also incorporates the best 
available science, including monitoring data from the Navy's marine 
mammal research efforts.

Species Not Included in the Analysis

    The species carried forward for analysis (and described in Table 5 
below) are those likely to be found in the PMSR Study Area based on the 
most recent data available, and do not include species that may have 
once inhabited or transited the area but have not been sighted in 
recent years (e.g., species which were extirpated from factors such as 
19th and 20th century commercial exploitation). Several species that 
may be present in the northwest Pacific Ocean have a low probability of 
presence in the PMSR Study Area. These species are considered 
extralimital (not anticipated to occur in the Study Area) or rare 
(occur in the Study Area sporadically, but sightings are rare). Species 
unlikely to be present in the PMSR Study Area or that are rare include 
the North Pacific right whale (Eubalaena japonica), rough-toothed 
dolphin (Steno bredanensis), and Steller sea lion

[[Page 37800]]

(Eumetopias jubatus), and these species have all been excluded from 
subsequent analysis for the reasons described below. There have been 
only four sightings, each of a single Northern Pacific right whale, in 
Southern California waters over approximately the last 30 years (in 
1988, 1990, 1992, and 2017) (Brownell et al., 2001; Carretta et al., 
1994; National Marine Fisheries Service, 2017b; WorldNow, 2017). 
Sightings off California are rare, and historically, even during the 
period of U.S. West Coast whaling through the 1800s, right whales were 
considered uncommon to rare off California (Reeves and Smith, 2010; 
Scammon, 1874). The range of the rough-toothed dolphin is known to 
occasionally include the Southern California coast during periods of 
warmer ocean temperatures, but there is no recognized stock for the 
U.S. West Coast (Carretta et al., 2019c). Several strandings were 
documented for this species in central and Southern California between 
1977 and 2002 (Zagzebski et al., 2006), but this species has not been 
observed during seven systematic ship surveys from 1991 to 2014 off the 
U.S. West Coast (Barlow, 2016). During 16 quarterly ship surveys off 
Southern California from 2004 to 2008, there was one encounter with a 
group of nine rough-toothed dolphins, which was considered an 
extralimital occurrence (Douglas et al., 2014). Steller sea lions range 
along the north Pacific from northern Japan to California (Perrin et 
al., 2009b), with centers of abundance and distribution in the Gulf of 
Alaska and Aleutian Islands (Muto et al., 2019). San Miguel Island and 
Santa Rosa Island were, in the past, the southernmost rookeries and 
haulouts for the Steller sea lions, but their range contracted 
northward in the 20th century, and now A[ntilde]o Nuevo Island off 
central California is currently the southernmost rookery (Muto et al., 
2019; National Marine Fisheries Service, 2008; Pitcher et al., 2007). 
Steller sea lions pups were known to be born at San Miguel Island up 
until 1981 (National Marine Fisheries Service, 2008; Pitcher et al., 
2007), and so, as the population continues to increase, it is 
anticipated that the Steller sea lions may re-establish a breeding 
colony on San Miguel Island in the future. In the Channel Islands and 
vicinity, despite the species' general absence from the area, a 
consistent but small number of Steller sea lions (one to two 
individuals at a time) have been sighted in recent years. Aerial 
surveys for pinnipeds in the Channel Islands from 2011 to 2015 
encountered a single Steller sea lion at SNI in 2013 (Lowry et al., 
2017). NMFS agrees with the Navy's assessment that these species are 
unlikely to occur in the PMSR Study Area and they are not discussed 
further.
    Southern sea otter (Enhydra lutris neris) occurs nearshore off the 
coast of central California, ranging from Half Moon Bay in the north to 
Point Conception and at SNI (Tinker et al., 2006; Tinker and Hatfield, 
2016; U.S. Geological Survey, 2014). Southern sea otters are managed by 
the U.S. Fish and Wildlife Service and therefore are not discussed 
further.

                                              Table 5--Marine Mammal Occurrence Within the PMSR Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         Status                   Stock abundance
                                                                        ----------------------------------------  (CV)/Nmin; most
          Common name              Scientific name          Stock                                                 recent abundance   PBR \3\   Annual M/
                                         \1\                                    MMPA                 ESA             survey \2\                  SI \4\
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale.....................  Balaenoptera        Eastern North       Depleted..........  Endangered........  1,496 (0.44)/            1.2     >=19.4
                                  musculus.           Pacific.                                                    1,051; 2014.
Bryde's whale..................  Balaenoptera        Eastern Tropical    ..................  ..................  unk; na..........        unk        unk
                                  brydei/edeni.       Pacific.
Fin whale......................  Balaenoptera        California,         Depleted..........  Endangered........  9,029 (0.12)/             81     >=43.7
                                  physalus.           Oregon, and                                                 8,127; 2014.
                                                      Washington.
Gray whale.....................  Eschrichtius        Eastern North       ..................  ..................  26,960 (0.05)/           801        131
                                  robustus.           Pacific.                                                    25,849; 2016.
                                                     Western North       Depleted..........  Endangered........  290 (na)/271;           0.12        unk
                                                      Pacific.                                                    2016.
Humpback whale.................  Megaptera           California,         Depleted..........  Threatened/         2,900 (0.05)/           16.7     >=42.1
                                  novaeangliae.       Oregon,                                 Endangered \1\.     2,784; 2019.
                                                      Washington.
Minke whale....................  Balaenoptera        California,         ..................  ..................  636 (0.72)/369;          3.5      >=1.3
                                  acutorostrata.      Oregon, and                                                 2014.
                                                      Washington.
Sei whale......................  Balaenoptera        Eastern North       Depleted..........  Endangered........  519 (0.4)/374;          0.75      >=0.2
                                  borealis.           Pacific.                                                    2014.
Baird's beaked whale...........  Berardius bairdii.  California,         ..................  ..................  2,697 (0.6)/              16          0
                                                      Oregon, and                                                 1,633; 2014.
                                                      Washington.
Common Bottlenose dolphin......  Tursiops truncatus  California Coastal  ..................  ..................  453 (0.06)/346;          2.7      >=2.0
                                                                                                                  2011.
                                                     California,         ..................  ..................  1,924 (0.54)/             11      >=1.6
                                                      Oregon, and                                                 1,255; 2014.
                                                      Washington
                                                      Offshore.
Cuvier's beaked whale..........  Ziphius             California,         ..................  ..................  3,274 (0.67)/             21       <0.1
                                  cavirostris.        Oregon, and                                                 2,059; 2014.
                                                      Washington.
Dall's porpoise................  Phocoenoides dalli  California,         ..................  ..................  25,750 (0.45)/           172        0.3
                                                      Oregon, and                                                 17,954; 2014.
                                                      Washington.
Dwarf sperm whale..............  Kogia sima........  California,         ..................  ..................  unk; 2014........        und          0
                                                      Oregon, and
                                                      Washington.
Harbor Porpoise................  Phocoena phocoena.  Morro Bay.........  ..................  ..................  2,917 \5\ (0.41)/     \5\ 66  \5\ >=0.4
                                                                                                                  1,384; 2012.
Killer whale...................  Orcinus orca......  Eastern North       ..................  ..................  300 (0.10)/276;          2.8          0
                                                      Pacific Offshore.                                           2012.
                                                     Eastern North       ..................  ..................  349 na/349; 2018.        3.5        0.4
                                                      Pacific Transient/
                                                      West Coast
                                                      Transient \6\.
Long-beaked common dolphin.....  Delphinus capensis  California........  ..................  ..................  101,305 (0.49)/          657     >=35.4
                                                                                                                  68,432; 2014.
Mesoplodont beaked whales \7\..  Mesoplodon spp....  California,         ..................  ..................  3,044 (0.54)/             20        0.1
                                                      Oregon, and                                                 1,967; 2014.
                                                      Washington.
Northern right whale dolphin...  Lissodelphis        California,         ..................  ..................  26,556 (0.44)/           179        3.8
                                  borealis.           Oregon, and                                                 18,608; 2014.
                                                      Washington.
Pacific white-sided dolphin....  Lagenorhynchus      California,         ..................  ..................  26,814 (0.28)/           191        7.5
                                  obliquidens.        Oregon, and                                                 21,195; 2014.
                                                      Washington.

[[Page 37801]]

 
Pygmy sperm whale..............  Kogia breviceps...  California,         ..................  ..................  4,111 (1.12)/             19          0
                                                      Oregon, and                                                 1,924; 2014.
                                                      Washington.
Risso's dolphins...............  Grampus griseus...  California,         ..................  ..................  6,336 (0.32)/             46      >=3.7
                                                      Oregon, and                                                 4,817; 2014.
                                                      Washington.
Short-beaked common dolphin....  Delphinus delphis.  California,         ..................  ..................  969,861 (0.17)/        8,393       >=40
                                                      Oregon, and                                                 839,325; 2014.
                                                      Washington.
Short-finned pilot whale.......  Globicephala        California,         ..................  ..................  836 (0.79)/466;          4.5        1.2
                                  macrorhynchus.      Oregon, and                                                 2014.
                                                      Washington.
Sperm whale....................  Physeter            California,         Depleted..........  Endangered........  1,997 (0.57)/            2.5        0.6
                                  macrocephalus.      Oregon, and                                                 1,270; 2014.
                                                      Washington.
Striped dolphin................  Stenella            California,         ..................  ..................  29,211 (0.20)/           238      >=0.8
                                  coeruleoalba.       Oregon, and                                                 24,782; 2014.
                                                      Washington.
Harbor seal....................  Phoca vitulina....  California........  ..................  ..................  30,968 na/27,348;      1,641         43
                                                                                                                  2012.
Northern elephant seal.........  Mirounga            California........  ..................  ..................  179,000 na/            4,882        8.8
                                  angustirostris.                                                                 81,368; 2010.
California sea lion............  Zalophus            U.S. Stock........  ..................  ..................  257,606 na/           14,011      >=321
                                  californianus.                                                                  233,515; 2014.
Northern fur seal..............  Callorhinus         California........  ..................  ..................  14,050 na/7,524;         451        1.8
                                  ursinus.                                                                        2013.
Guadalupe fur seal.............  Arctocephalus       Mexico to           Depleted..........  Threatened........  34,187 unk/            1,602      >=3.8
                                  townsendi.          California.                                                 31,109; 2013.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Taxonomy follows Committee on Taxonomy (2018).
\2\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. The most recent abundance survey that is reflected in the abundance
  estimate is presented; there may be more recent surveys that have not yet been incorporated into the estimate.
\3\ PBR is the Potential biological removal, 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 size (OSP).
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a range.
\5\ The abundance number as presented is from the ``fine-scale transects'' as documented in Forney et al. (2014). PBR and M/SI are from draft 2020 SAR
  for the Pacific (Carretta et al., 2020).
\6\ This stock is mentioned briefly in the Pacific Stock Assessment Report and referred to as the ``Eastern North Pacific Transient'' stock, however,
  the Alaska Stock Assessment Report contains assessments of all transient killer whale stocks in the Pacific, and the Alaska Stock Assessment Report
  refers to this same stock as the ``West Coast Transient'' stock (Muto et al., 2019).
\7\ The six Mesoplodont beaked whale species off California are M. densirostris, M. carlhubbsi, M. ginkgodens, M. perrini, M. peruvianus, M. stejnegeri.
Notes: na = not available; unk = unknown ; und = undetermined or not provided in the draft 2020 SAR for the Pacific (Carretta et al., 2020) (Carretta et
  al., 2019b).

    Further, after Navy completed their modeling analysis, the 
following species/stocks had zero calculated estimated takes: Bryde's 
whale (Eastern Tropical Pacific), Gray whale (Western North Pacific), 
Sei whale (Eastern North Pacific), Baird's beaked whale (California, 
Oregon, and Washington), Bottlenose dolphin (California Coastal), 
Cuvier's beaked whale (California, Oregon, and Washington), Harbor 
Porpoise (Morro Bay), Killer whale (Eastern North Pacific Offshore, 
Eastern North Pacific Transient or West Coast Transient), Mesoplodont 
spp. (California, Oregon, and Washington), Short-finned pilot whale 
(California, Oregon, and Washington), and Northern fur seal 
(California). NMFS agrees with the Navy's analysis; therefore, these 
species are excluded from further analysis.
    Below, we include additional information about the marine mammals 
in the area of the Specified Activities that informs our analysis, such 
as identifying known areas of important habitat or behaviors, or where 
Unusual Mortality Events (UME) have been designated.

Critical Habitat

    The statutory definition of occupied critical habitat refers to 
``physical or biological features essential to the conservation of the 
species,'' but the ESA does not specifically define or further describe 
these features. ESA-implementing regulations at 50 CFR 424.02 (as 
amended, 84 FR 45020; August 27, 2019), however, define such features 
as follows: The features that occur in specific areas and that are 
essential to support the life-history needs of the species, including 
but not limited to, water characteristics, soil type, geological 
features, sites, prey, vegetation, symbiotic species, or other 
features. A feature may be a single habitat characteristic, or a more 
complex combination of habitat characteristics. Features may include 
habitat characteristics that support ephemeral or dynamic habitat 
conditions. Features may also be expressed in terms relating to 
principles of conservation biology, such as patch size, distribution 
distances, and connectivity.
    On April 21, 2021, NMFS issued a final rule to designate critical 
habitat in nearshore waters of the North Pacific Ocean for the 
endangered Central America DPS and the threatened Mexico DPS of 
humpback whales (86 FR 21082). Critical habitat for the Central America 
DPS and Mexico DPS was established within the California Current 
Ecosystem (CCE) off the coasts of California, Oregon, and Washington, 
representing areas of key foraging habitat. Prey of sufficient quality, 
abundance, and accessibility within humpback whale feeding areas to 
support feeding and population growth is identified an essential 
feature to the conservation of these whales. Because humpback whales 
only rarely feed on breeding grounds and during migrations, humpback 
whales must have access to adequate prey resources within their feeding 
areas to build up their fat stores and meet the nutritional and energy 
demands associated with individual survival, growth, reproduction, 
lactation, seasonal migrations, and other normal life functions. Given 
that each of three humpback whale DPSs very clearly rely on the feeding 
areas while within U.S. waters, prey has been identified as a 
biological feature that is essential to the conservation of the whales. 
The prey essential feature was specifically defined as follows: Prey 
species, primarily euphausiids and small pelagic schooling fishes of

[[Page 37802]]

sufficient quality, abundance, and accessibility within humpback whale 
feeding areas to support feeding and population growth.
    NMFS considered 19 units of habitat as critical habitat for the 
listed humpback whale DPSs. There is overlap between the PMSR Study 
Area and portions of the habitat designated Units 17 and 18 (see Figure 
3.7-5 of the 2020 PMSR DEIS/OEIS) in the final critical habitat rule 
(86 FR 21082), which are described below.
    Unit 17, referred to as the ``Central California Coast Area,'' 
extends from 36[deg]00' N to a southern boundary at 34[deg]30' N. The 
nearshore boundary is defined by the 30-m isobath, and the seaward 
boundary is drawn along the 3,700-m isobath. This unit includes waters 
off of southern Monterey County, and San Luis Obispo and Santa Barbara 
Counties. Unit 17 covers 6,697 nmi\2\ of marine habitat. This unit 
encompasses Morro Bay to Point Sal Biologically Important Area (BIA; 
see next section) and typically supports high density feeding 
aggregations of humpback whales from April to November (Calambokidis et 
al. 2015). Based on acoustic survey data collected during 2004-2009, 
large krill hotspots, ranging from 700 km\2\ to 2,100 km\2\, occur off 
Big Sur, San Luis Obispo, and Point Sal (Santora et al. 2011). Hotspots 
with persistent, heightened abundance of krill were also reported in 
this unit in association with bathymetric submarine canyons (Santora et 
al. 2018). This is the northernmost portion of humpback whale critical 
habitat that overlaps with the PMSR Study Area.
    Unit 18, referred to as the ``Channel Islands Area,'' extends from 
a northern boundary at 34[deg]30' N to a boundary line that extends 
from Oxnard, CA seaward to the 3,700-m isobath, along which the 
offshore boundary is drawn. The 50-m isobath forms the shoreward 
boundary. This unit includes waters off of Santa Barbara and Ventura 
counties. This unit covers 9,799 nmi\2\ of marine habitat. This unit 
encompasses the Santa Barbara Channel-San Miguel BIA, which supports 
high density feeding aggregations of humpback whales during March 
through September (Calambokidis et al. 2015). Based on acoustic survey 
data collected during 2004-2009, a krill hotspot of about 780 km\2\ has 
been documented off Point Conception (Santora et al. 2011). Some 
additional krill hotspots have also been observed in this unit in 
association with bathymetric submarine canyons (Santora et al. 2018). 
Coastal waters managed by the Navy, as addressed within the Point Mugu 
Integrated Natural Resources Management Plan (INRMP) and SNI INRMP, are 
not included in the proposed designation as these areas were determined 
by NMFS to be ineligible for designation as critical habitat under 
section 4(a)(3)(B)(i) of the ESA (84 FR 54354; October 9, 2019).The 
Navy does not anticipate national security impacts resulting from 
critical habitat designation in the portion of Region/Unit 18 that 
overlaps with the PMSR Study Area.

Biologically Important Areas

    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. An 
interactive map of the BIAs may be found here: https://cetsound.noaa.gov/biologically-important-area-map.
    BIAs off the West Coast of the continental United States with the 
potential to overlap portions of the PMSR Study Area include the 
following feeding and migration areas for blue whales, gray whales, and 
humpback whales and are described in further detail below (Calambokidis 
et al., 2015).
Blue Whale Feeding BIAs
    Three blue whale feeding BIAs overlap with the PMSR Study Area (see 
Figure 3.7-2 of the 2020 PMSR DEIS/OEIS). The Point Conception/Arguello 
to Point Sal Feeding Area and Santa Barbara Channel and San Miguel 
Feeding Area have large portions within the PMSR Study Area, 87 and 61 
percent respectively. The San Nicolas Island Feeding Area is entirely 
within the PMSR Study Area (Calambokidis et al., 2015a). Feeding by 
blue whales occurs from June through October in these BIAs 
(Calambokidis et al., 2015a).
Gray Whale Migration BIAs
    Four gray whale migration BIAs overlap with the PMSR Study Area 
(see Figure 3.7-3 of the 2020 PMSR DEIS/OEIS). The northward migration 
of the Eastern North Pacific stock of gray whales to the feeding 
grounds in Arctic waters, Alaska, the Pacific Northwest, and Northern 
California occurs in two phases: Northbound Phase A and Northbound 
Phase B (Calambokidis et al., 2015). Northbound Phase A migration BIA 
consists mainly of adults and juveniles that lead the beginning of the 
north-bound migration from late January through July, peaking in April 
through July. Newly pregnant females go first to maximize feeding time, 
followed by adult females and males, and then juveniles (Jones and 
Swartz, 2009). The Northbound Phase B migration BIA consists primarily 
of cow-calf pairs that begin their northward migration later (March 
through July), as they remain on the reproductive grounds longer to 
allow calves to strengthen and rapidly increase in size before the 
northward migration (Jones and Swartz, 2009; Urban-Ramirez et al., 
2003). The Potential presence migration BIA (January through July; 
October through December) and the Southbound--All migration BIA 
(October through March) routes pass through the waters of the PMSR 
Study Area.
Humpback Whale Feeding BIAs
    Two humpback whale feeding areas overlap with the PMSR Study Area 
(Calambokidis et al., 2015) (see Figure 3.7-4 of the 2020 PMSR DEIS/
OEIS). These BIAs include the Morro Bay to Point Sal feeding area 
(April through November) and the Santa Barbara Channel-San Miguel 
feeding area (March through September) (Calambokidis et al., 2015). The 
majority of these BIAs overlap with the PMSR Study Area (approximately 
75 percent).

National Marine Sanctuaries

    Under Title III of the Marine Protection, Research, and Sanctuaries 
Act of 1972 (also known as the National Marine Sanctuaries Act (NMSA)), 
NOAA can establish as national marine sanctuaries (NMS), areas of the 
marine environment with special conservation, recreational, ecological, 
historical, cultural, archaeological, scientific, educational, or 
aesthetic qualities. Sanctuary regulations prohibit or regulate 
activities that could destroy, cause the loss of, or injure sanctuary 
resources pursuant to the regulations for that sanctuary and other 
applicable law (15 CFR part 922). NMSs are managed on a site-specific 
basis, and each sanctuary has site-specific regulations. Most, but not 
all, sanctuaries have site-specific regulatory exemptions from the 
prohibitions for certain military activities. Separately, section 
304(d) of the NMSA requires Federal agencies to consult with the Office 
of National Marine Sanctuaries whenever their activities are likely to 
destroy, cause the loss of, or injure a sanctuary resource.
    There are two NMSs managed by the Office of National Marine 
Sanctuaries within the PMSR Study Area: The Channel Islands NMS and a 
small portion of the Monterey Bay NMS. The

[[Page 37803]]

Channel Islands NMS is an ecosystem-based managed sanctuary consisting 
of an area of 1,109 nmi\2\ around Anacapa Island, Santa Cruz Island, 
Santa Rosa Island, San Miguel Island, and Santa Barbara Island to the 
south. It encompasses sensitive habitats (e.g., kelp forest habitat, 
deep benthic habitat) and includes various shipwrecks and maritime 
heritage artifacts. The Channel Islands NMS waters and its remote, 
isolated position at the confluence of two major ocean currents support 
significant biodiversity of marine mammals, fish, and invertebrates. At 
least 33 species of cetaceans have been reported in the Channel Islands 
NMFS region with common species, including: Long-beaked common dolphin, 
short-beaked common dolphin, Bottlenose dolphin, Pacific white-sided 
dolphin, Northern right whale dolphin, Risso's dolphin, California gray 
whale, Blue whale, and Humpback whale. The three species of pinnipeds 
that are commonly found throughout or in part of the Channel Islands 
NMS include: California sea lion, Northern elephant seal, and Pacific 
harbor seal. About 877 nmi\2\, or 79 percent of the Channel Island NMS, 
occurs within the PMSR Study Area (see Chapter 6 of the 2020 PMSR DEIS/
OEIS and Figure 6.1-1). The Monterey Bay NMS is an ecosystem-based 
managed sanctuary consisting of an area of 4,601 nmi\2\ stretching from 
Marin to Cambria and extending an average of 30 miles from shore. The 
Monterey Bay NMS contains extensive kelp forests and one of North 
America's largest underwater canyons and closest-to-shore deep ocean 
environments. Its diverse marine ecosystem also includes rugged rocky 
shores, wave-swept sandy beaches and tranquil estuaries. These habitats 
support a variety of marine life, including 36 species of marine 
mammals, more than 180 species of seabirds and shorebirds, at least 525 
species of fishes, and an abundance of invertebrates and algae. Of the 
36 species of marine mammals, six are pinnipeds with California sea 
lions being the most common, and the remainder are twenty-six species 
of cetaceans. Only 19 nmi\2\, or less than 1 percent of the Monterey 
Bay NMS, occurs within the PMSR Study Area (see Chapter 6 of the 2020 
PMSR DEIS/OEIS and Figure 6.1-1).

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. From 1991 to the 
present, there have been 14 formally recognized UMEs affecting marine 
mammals in California and involving species under NMFS' jurisdiction. 
Three UMEs with ongoing or recently closed investigations in the PMSR 
Study Area that inform our analysis are discussed below. The California 
sea lion UME in California was closed on May 6, 2020. The Guadalupe fur 
seal UME in California and the gray whale UME along the west coast of 
North America are active and involve ongoing investigations.
California Sea Lion UME
    From January 2013 through September 2016, a greater than expected 
number of young malnourished California sea lions (Zalophus 
californianus) stranded along the coast of California. Sea lions 
stranding from an early age (6-8 months old) through two years of age 
(hereafter referred to as juveniles) were consistently underweight 
without other disease processes detected. Of the 8,122 stranded 
juveniles attributed to the UME, 93 percent stranded alive (n = 7,587, 
with 3,418 of these released after rehabilitation) and 7 percent (n = 
531) stranded dead. Several factors are hypothesized to have impacted 
the ability of nursing females and young sea lions to acquire adequate 
nutrition for successful pup rearing and juvenile growth. In late 2012, 
decreased anchovy and sardine recruitment (CalCOFI data, July 2013) may 
have led to nutritionally stressed adult females. Biotoxins were 
present at various times throughout the UME, and while they were not 
detected in the stranded juvenile sea lions (whose stomachs were empty 
at the time of stranding), biotoxins may have impacted the adult 
females' ability to support their dependent pups by affecting their 
cognitive function (e.g., navigation, behavior towards their 
offspring). Therefore, the role of biotoxins in this UME, via its 
possible impact on adult females' ability to support their pups, is 
unclear. The proposed primary cause of the UME was malnutrition of sea 
lion pups and yearlings due to ecological factors. These factors 
included shifts in distribution, abundance and/or quality of sea lion 
prey items around the Channel Island rookeries during critical sea lion 
life history events (nursing by adult females, and transitioning from 
milk to prey by young sea lions). These prey shifts were most likely 
driven by unusual oceanographic conditions at the time due to the event 
known as the ``Warm Water Blob'' and El Ni[ntilde]o. This investigation 
closed on May 6, 2020. Please refer to: https://www.fisheries.noaa.gov/national/marine-life-distress/2013-2016-california-sea-lion-unusual-mortality-event-california for more information on this UME.
Guadalupe Fur Seal UME
    Increased strandings of Guadalupe fur seals began along the entire 
coast of California in January 2015 and were eight times higher than 
the historical average (approximately 10 seals/yr). Strandings have 
continued since 2015 and remained well above average through 2020. 
Numbers by year are as follows: 2015 (98), 2016 (76), 2017 (62), 2018 
(45), 2019 (116), 2020 (95 as of December 17, 2020). The total number 
of Guadalupe fur seals stranding in California from January 1, 2015, 
through December 17, 2020, in the UME is 492. Strandings of Guadalupe 
fur seals became elevated in the spring of 2019 in Washington and 
Oregon, and strandings for seals in these two states subsequently 
(starting from January 1, 2019) have been added to the UME. The current 
total number of strandings in Washington and Oregon is 133 seals, 
including 91 in 2019 and 42 in 2020 as of December 17, 2020. Strandings 
are seasonal and generally peak in April through June of each year. The 
Guadalupe fur seal strandings involved the stranding of mostly weaned 
pups and juveniles (1-2 years old), with both live and dead strandings 
occurring. Current studies of this UME find that the majority of 
stranded animals experienced primary malnutrition with secondary 
bacterial and parasitic infections. The California portion of this UME 
was occurring in the same area where the 2013-2016 California sea lion 
UME occurred. This investigation is ongoing. Please refer to: https://www.fisheries.noaa.gov/national/marine-life-distress/2015-2020-guadalupe-fur-seal-unusual-mortality-event-california for more 
information on this UME.
Gray Whale UME
    Since January 1, 2019, elevated levels of gray whale strandings 
have occurred along the west coast of North America, from Mexico to 
Canada. As of December 17, 2020, there have been a total of 385 
strandings along the coasts of the United States, Canada, and Mexico, 
with 201 of those strandings occurring along the U.S. coast. Of the 
strandings on the U.S. coast, 93 have occurred in Alaska, 47 in 
Washington, 9 in Oregon, and 52 in California. Partial necropsy 
examinations conducted on a subset of stranded whales have shown 
evidence of poor to thin body condition, killer whale predation, and 
human

[[Page 37804]]

interactions. As part of the UME investigation process, NOAA is 
assembling an independent team of scientists to coordinate with the 
Working Group on Marine Mammal UMEs to review the data collected, 
sample stranded whales, and determine the next steps for the 
investigation. Please refer to: https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2020-gray-whale-unusual-mortality-event-along-west-coast.

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 Navy has requested authorization for the take of marine mammals 
that may occur incidental to training and testing activities in the 
PMSR Study Area. The Navy analyzed potential impacts to marine mammals 
from explosive sources, target and missile launches from SNI, and from 
vessel use in its rulemaking/LOA application. NMFS carefully reviewed 
the information provided by the Navy along with independently reviewing 
applicable scientific research and literature and other information to 
evaluate the potential effects of the Navy's activities on marine 
mammals.
    Other potential impacts to marine mammals from training and testing 
activities in the PMSR Study Area were analyzed in the 2020 PMSR DEIS/
OEIS, in consultation with NMFS as a cooperating agency. In particular, 
the Navy determined that these activities were unlikely to result in 
any incidental take from vessel strike or in any serious injury or 
mortality from explosive detonations (discussed in this section below), 
and the Navy has not requested authorizations of any such incidental 
take. NMFS agrees with these determinations by the Navy. Accordingly, 
in this proposed rule NMFS' analysis focuses on the potential effects 
on marine mammals from the activity components that may cause the take 
of marine mammals: Exposure to explosive stressors and launches.
    For the purpose of MMPA incidental take authorizations, NMFS' 
effects assessments serve four primary purposes: (1) To determine 
whether the specified activities would have a negligible impact on the 
affected species or stocks of marine mammals (based on whether it is 
likely that the activities would adversely affect the species or stocks 
through effects on annual rates of recruitment or survival); (2) to 
determine whether the specified activities would have an unmitigable 
adverse impact on the availability of the species or stocks for 
subsistence uses; (3) to prescribe the permissible methods of taking 
(i.e., Level B harassment (behavioral disturbance, incurred directly or 
as a result of temporary threshold shift (TTS)), and Level A harassment 
(permanent threshold shift (PTS) and non-auditory injury)), including 
identification of the number and types of take that could occur by 
harassment, serious injury, or mortality, and to prescribe other means 
of effecting the least practicable adverse impact on the species or 
stocks and their habitat (i.e., mitigation measures); and (4) to 
prescribe requirements pertaining to monitoring and reporting.
    Marine mammals may be affected by Navy activities by sensory 
impairment (permanent and temporary threshold shifts and acoustic 
masking), physiological responses (particular stress responses), direct 
behavioral disturbance, or habitat effects. The Estimated Take of 
Marine Mammals section discusses how the potential effects on marine 
mammals from the impulsive acoustic sources considered in this rule 
relate to the MMPA definitions of Level A harassment and Level B 
harassment, and quantifies those effects that rise to the level of a 
take. The Preliminary Analysis and Negligible Impact Determination 
section assesses whether the proposed authorized take would have a 
negligible impact on the affected species and stocks.
    Sections 6, 7, and 9 of the Navy'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 other stressors produced 
through the use explosives detonating at or near the surface and noise 
from launch events on SNI. We have reviewed the Navy'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.
    Additionally, NMFS has included a comprehensive discussion of the 
potential effects of similar activities on marine mammals, including 
specifically from Navy testing and training exercises that use 
explosives, in other Federal Register notices. For additional detail, 
we refer the reader to these notices; please see, 85 FR 72312 (November 
9, 2020) (Navy testing and training, including explosives); 84 FR 28462 
(June 12, 2019) (Navy IHA on target and missile launches from SNI); and 
79 FR 32678 (June 6, 2014) (Navy previous rule on target and missile 
launches from SNI), or view documents available online at 
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
    Below we provide a brief technical background on sound, on the 
characteristics of certain sound types, and on metrics used in this 
proposal, as well as a brief overview of the potential effects to 
marine mammals associated with the Navy's proposed activities. 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 as well as by impulsive noise target and missile launches from 
SNI. Exposure to noise or pressure resulting from these detonations and 
launches could result in non-lethal injury (Level A harassment) or 
disturbance (Level B harassment). The potential effects of impulsive 
sound and pressure from the proposed training and testing activities 
may include one or more of the following: Tolerance, masking, 
disturbance, hearing threshold shift, and stress responses. In 
addition, NMFS also considered the potential for harassment from 
vessels and serious injury and mortality from explosive detonations.

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, e.g., Au and

[[Page 37805]]

Hastings (2008); Richardson et al. (1995); 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).
    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), as is the case for sound produced by the 
pile driving activity considered here. 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,

[[Page 37806]]

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.

Serious Injury or Mortality From Explosive Detonations

    Serious injury or mortality to marine mammals from explosive 
detonations 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 is usually observed as barotrauma of gas-containing 
structures (e.g., lung and gut) and structural damage to the auditory 
system (Greaves et al., 1943; Office of the Surgeon General, 1991; 
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 by restricting 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.
    The Navy performed a quantitative analysis (refer to the Navy's 
Acoustic Effects Model section) to estimate the probability that marine 
mammals could be exposed to the sound and energy from explosions during 
Navy testing and training activities and the effects of those 
exposures. 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 no explosives 
detonated underwater for the proposed activities, and those that 
detonate at or near the surface of the water are unlikely to transfer 
energy underwater sufficient to result in non-auditory injury (GI 
injury or lung injury) or mortality. NMFS agrees with the Navy'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 Navy did not request and NMFS does not propose 
it for authorization or discuss 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).

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). 
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 [dB]) 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 in Section 6.4.1.2, (Loss of Hearing Sensitivity and Auditory 
Injury) of the Navy's application.
    Marine mammal TTS data from impulsive sources are limited to two 
studies with measured TTS of 6 dB or more: Finneran et al. (2002) 
reported behaviorally measured TTSs of 6 and 7 dB in a beluga exposed 
to single impulses from a seismic water gun, and Lucke et al. (2009) 
reported Audio-evoked Potential measured TTS of 7-20 dB in a harbor 
porpoise exposed to single impulses from a seismic air gun.
    In addition to these data, Kastelein et al. (2015a) reported 
behaviorally measured mean TTS of 4 dB at 8 kHz and 2 dB at 4 kHz after 
a harbor porpoise was exposed to a series of impulsive sounds produced 
by broadcasting underwater recordings of impact pile driving strikes 
through underwater sound projectors. The cumulative SEL was 
approximately 180 decibels referenced to 1 micropascal squared seconds 
(dB re 1 [mu]Pa\2\s). The pressure waveforms for the simulated pile 
strikes exhibited significant

[[Page 37807]]

``ringing'' not present in the original recordings, and most of the 
energy in the broadcasts was between 500 and 800 Hz. As a result, some 
questions exist regarding whether the fatiguing signals were 
representative of underwater pressure signatures from impact pile 
driving.
    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. Finneran et al. (2003) exposed two sea 
lions to single impulses from an arc-gap transducer with no measurable 
TTS (maximum unweighted SEL = 163 dB re 1 [mu]Pa\2\s, peak SPL = 183 dB 
re 1 [mu]Pa).
    Numerous studies have directly examined noise-induced hearing loss 
in marine mammals from non-impulsive sources (see Finneran, 2015). In 
these studies, hearing thresholds were measured in marine mammals 
before and after exposure to intense sounds. The difference between the 
pre-exposure and post-exposure thresholds was then used to determine 
the amount of TTS at various post-exposure times. The major findings 
from these studies, which include the following, highlight general 
concepts that are thought to be applicable across all types of sounds:
     The amount of TTS varies with the hearing test frequency. 
As the exposure SPL increases, the frequency at which the maximum TTS 
occurs also increases (Kastelein et al., 2014b). For high-level 
exposures, the maximum TTS typically occurs one-half to one octave 
above the exposure frequency (Finneran et al., 2007; Mooney et al., 
2009a; Nachtigall et al., 2004; Popov et al., 2011; Popov et al., 2013; 
Schlundt et al., 2000). The overall spread of TTS from tonal exposures 
can therefore extend over a large frequency range (i.e., narrowband 
exposures can produce broadband [greater than one octave] TTS).
     The amount of TTS increases with exposure SPL and duration 
and is correlated with sound exposure level (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, 2010b; 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 
overestimate 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.
     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.
     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., 
2014a; 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 amount of observed TTS tends to decrease with 
increasing time following the exposure; however, the relationship is 
not monotonic (i.e., increasing exposure does not always increase TTS). 
The time required for complete recovery of hearing depends on the 
magnitude of the initial shift; for relatively small shifts recovery 
may be complete in a few minutes, while large shifts (e.g., ~40 dB) may 
require several days for recovery. Under many circumstances TTS 
recovers linearly with the logarithm of time (Finneran et al., 2010a, 
2010b; Finneran and Schlundt, 2013; Kastelein et al., 2012a; Kastelein 
et al., 2012b; Kastelein et al., 2013a; Kastelein et al., 2014a, 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).
    The proposed activities include both TTS and a limited amount of 
PTS on some marine mammals.
    Hearing Loss from SNI Target and Missile Launches--Missile launches 
are characterized by sudden onset of sound, moderate to high peak sound 
levels (depending on the type of missile and distance), and short sound 
duration. Although it is possible that some pinnipeds may incur TTS 
during launches from SNI, hearing impairment has not been measured for 
pinniped species exposed to launch sounds. Auditory brainstem response 
(i.e., hearing assessment using measurements of electrical responses of 
the brain) was used to demonstrate that harbor seals did not exhibit 
loss in hearing sensitivity following launches of large rockets at 
Vandenberg Air Force Base (VAFB) (Thorson et al., 1999; Thorson et al., 
1998). However, the hearing tests did not begin until at least 45 
minutes after the launch; therefore, harbor seals may have incurred TTS 
which was undetectable by the time testing was begun. There was no sign 
of PTS in any of the harbor seals tested (Thorson et al., 1999; Thorson 
et al., 1998). Since 2001, no launch events at SNI have exposed 
pinnipeds to noise levels at or exceeding those where PTS could be 
incurred.
    Based on measurements of received sound levels during previous 
launches at SNI (Burke 2017; Holst et al., 2010; Holst et al., 2005a; 
Holst et al., 2008; Holst et al., 2011; Ugoretz 2016; Ugoretz and 
Greene Jr. 2012), the Navy expects that there is a very limited 
potential of TTS for a few of the pinnipeds present, particularly for 
phocids. Available evidence from launch monitoring at SNI in 2001-2017 
suggests that only a small number of launch events produced sound 
levels that could elicit TTS for some pinnipeds (Burke 2017; Holst et 
al., 2008; Holst et al., 2011; Ugoretz 2016; Ugoretz and Greene Jr. 
2012). In general, if any TTS were to occur to pinnipeds, it is 
expected to be mild and reversible. It is possible that some launch 
sounds as measured close to the launchers may exceed the permanent 
threshold shift (PTS) criteria, but it is not expected that any 
pinnipeds would be close enough to the launchers to be exposed to 
sounds strong enough to cause PTS. Due to the expected sound levels of 
the activities proposed and the distance of the activity from marine 
mammal habitat, the effects of sounds from the proposed activities are 
unlikely to result in PTS.

[[Page 37808]]

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 associate 
with ``stress.'' These responses have a relatively short duration and 
may or may not have 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 hypothalmus-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.

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. 
As described in detail in the 2020 PMSR DSEIS/OEIS, 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). There are 
no direct observations of masking in marine mammals due to exposure to 
sound from explosive detonations or launches and nor would they be 
predicted given the shorter duration of these sounds.

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 (nature and magnitude) 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). These may 
be of limited relevance to the proposed activities given that airborne 
sound, and not underwater sound, may result in harassment of marine 
mammals as a result of the proposed activities; however we present this 
information as background on the potential impacts of sound on marine 
mammals. 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; Wartzok et al., 2003; 
Nowacek et al., 2007).
    The onset of noise can result in temporary, short-term changes in 
an animal's typical behavior and/or

[[Page 37809]]

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. (2012) outlined an approach to assessing the effects 
of sound on marine mammals that incorporates contextual-based factors. 
The authors recommend considering not just the received level of sound, 
but also the activity the animal is engaged in at the time the sound is 
received, the nature and novelty of the sound (i.e., is this a new 
sound from the animal's perspective), and the distance between the 
sound source and the animal. They submit that this ``exposure 
context,'' as described, greatly influences the type of behavioral 
response exhibited by the animal. Forney et al. (2017) also point out 
that an apparent lack of response (e.g., no displacement or avoidance 
of a sound source) may not necessarily mean there is no cost to the 
individual or population, as some resources or habitats may be of such 
high value that animals may choose to stay, even when experiencing 
stress or hearing loss. Forney et al. (2017) recommend considering both 
the costs of remaining in an area of noise exposure such as TTS, PTS, 
or masking, which could lead to an increased risk of predation or other 
threats or a decreased capability to forage, and the costs of 
displacement, including potential increased risk of vessel strike, 
increased risks of predation or competition for resources, or decreased 
habitat suitable for foraging, resting, or socializing. This sort of 
contextual information is challenging to predict with accuracy for 
ongoing activities that occur over large spatial and temporal expanses. 
However, distance is one contextual factor for which data exist to 
quantitatively inform a take estimate, and the method for predicting 
Level B harassment in this 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.
    Behavioral Disturbance from SNI Target and Missile Launches--
Pinnipeds may be exposed to airborne sounds that have the potential to 
result in behavioral harassment, depending on an animal's distance from 
the sound and the type of missile being launched. Sound could cause 
hauled out pinnipeds to exhibit changes in their normal behavior, such 
as temporarily abandoning their habitat.
    Responses of pinnipeds on beaches exposed to acoustic disturbance 
arising from launches are highly variable. Harbor seals can be more 
reactive when hauled out compared to other species, such as northern 
elephant seals. Northern elephant seals generally exhibit no reaction 
at all, except perhaps a heads-up response or some stirring. If 
northern elephant seals do react, it may occur if California sea lions 
are in the same area mingled with the northern elephant seals and the 
sea lions react strongly. Responsiveness also varies with time of year 
and age class, with juvenile pinnipeds being more likely to react by 
leaving the haulout site. The probability and type of behavioral 
response will also depend on the season, the group composition of the 
pinnipeds, and the type of activity in which they are engaged. For 
example, in some cases, harbor seals at SNI appear to be more 
responsive during the pupping/breeding season (Holst et al. 2005a; 
Holst et al. 2008), while in others, mothers and pups seem to react 
less to launches than lone individuals (Ugoretz and Greene Jr. 2012), 
and California sea lions seem to be consistently less responsive during 
the pupping season (Holst et al. 2010; Holst et al. 2005a; Holst et al. 
2008; Holst et al. 2011; Holst et al. 2005b; Ugoretz and Greene Jr. 
2012). Though pup abandonment could theoretically result from these 
reactions, site-specific monitoring data indicate that pup abandonment 
is not likely to occur as a result of the specified activity because it 
has not been previously observed. While the reactions are variable, and 
can involve abrupt movements by some individuals, biological impacts of 
these responses appear to be limited. The responses are not expected to 
result in significant injury or mortality, or long-term negative 
consequences to individuals or pinniped populations on SNI.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are

[[Page 37810]]

predictable and unvarying. The opposite process is sensitization, when 
an unpleasant experience leads to subsequent responses, often in the 
form of avoidance, at a lower level of exposure. Behavioral state may 
affect the type of response as well. For example, animals that are 
resting may show greater behavioral change in response to disturbing 
sound levels than animals that are highly motivated to remain in an 
area for feeding (Richardson et al., 1995; NRC, 2003; Wartzok et al., 
2003).
    It is possible that launch-induced flushing or stampedes could have 
adverse impacts on individual pinnipeds on the west end of SNI. Bowles 
and Stewart (1980) reported that harbor seals on San Miguel Island 
reacted to low-altitude jet overflights with alert postures and often 
with rapid movement across the haulout sites, especially when aircraft 
were visible. However, on SNI during missile launches in 2001-2017, 
there was no evidence of launch noise-related injuries or deaths (Burke 
2017; Holst et al. 2010; Holst et al. 2005a; Holst et al. 2008; Holst 
et al. 2011; Ugoretz 2016; Ugoretz and Greene Jr. 2012). On several 
occasions, harbor seals and California sea lion adults moved near and 
sometimes over older pups (i.e., greater than four months old) as the 
animals moved in response to the launch noises, but the pups were not 
injured (Holst et al., 2010; Holst et al., 2005a; Holst et al., 2008; 
Holst et al., 2011; Ugoretz and Greene Jr. 2012).

Vessel Strike

    Vessel strikes from commercial, recreational, and military vessels 
are known to affect large whales and have resulted in serious injury 
and occasional fatalities to cetaceans (Berman-Kowalewski et al., 2010; 
Calambokidis, 2012; Douglas et al., 2008; Laggner 2009; Lammers et al., 
2003). Records of collisions date back to the early 17th century, and 
the worldwide number of collisions appears to have increased steadily 
during recent decades (Laist et al., 2001; Ritter 2012).
    Numerous studies of interactions between surface vessels and marine 
mammals have demonstrated that free-ranging marine mammals often, but 
not always (e.g., McKenna et al., 2015), engage in avoidance behavior 
when surface vessels move toward them. It is not clear whether these 
responses are caused by the physical presence of a surface vessel, the 
underwater noise generated by the vessel, or an interaction between the 
two (Amaral and Carlson, 2005; Au and Green, 2000; Bain et al., 2006; 
Bauer 1986; Bejder et al., 1999; Bejder and Lusseau, 2008; Bejder et 
al., 2009; Bryant et al., 1984; Corkeron, 1995; Erbe, 2002; 
F[eacute]lix, 2001; Goodwin and Cotton, 2004; Lemon et al., 2006; 
Lusseau, 2003; Lusseau, 2006; Magalhaes et al., 2002; Nowacek et al., 
2001; Richter et al., 2003; Scheidat et al., 2004; Simmonds, 2005; 
Watkins, 1986; Williams et al., 2002; Wursig et al., 1998). Several 
authors suggest that the noise generated during motion is probably an 
important factor (Blane and Jaakson, 1994; Evans et al., 1992; Evans et 
al., 1994). Water disturbance may also be a factor. These studies 
suggest that the behavioral responses of marine mammals to surface 
vessels are similar to their behavioral responses to predators. 
Avoidance behavior is expected to be even stronger in the subset of 
instances during which the Navy is conducting training or testing 
activities using explosives.
    The marine mammals most vulnerable to vessel strikes are those that 
spend extended periods of time at the surface in order to restore 
oxygen levels within their tissues after deep dives (e.g., sperm 
whales). In addition, some baleen whales seem generally unresponsive to 
vessel sound, making them more susceptible to vessel collisions 
(Nowacek et al., 2004). These species are primarily large, slow moving 
whales.
    Some researchers have suggested the relative risk of a vessel 
strike can be assessed as a function of animal density and the 
magnitude of vessel traffic (e.g., Fonnesbeck et al., 2008; Vanderlaan 
et al., 2008). Differences among vessel types also influence the 
probability of a vessel strike. The ability of any ship to detect a 
marine mammal and avoid a collision depends on a variety of factors, 
including environmental conditions, ship design, size, speed, and 
ability and number of personnel observing, as well as the behavior of 
the animal. Vessel speed, size, and mass are all important factors in 
determining if injury or death of a marine mammal is likely due to a 
vessel strike. For large vessels, speed and angle of approach can 
influence the severity of a strike. For example, Vanderlaan and Taggart 
(2007) found that, between vessel speeds of 8.6 and 15 knots, the 
probability that a vessel strike is lethal increases from 0.21 to 0.79. 
Large whales also do not have to be at the water's surface to be 
struck. Silber et al. (2010) found when a whale is below the surface 
(about one to two times the vessel draft), under certain circumstances 
(vessel speed and location of the whale relative to the ship's 
centerline), there is likely to be a pronounced propeller suction 
effect. This suction effect may draw the whale into the hull of the 
ship, increasing the probability of propeller strikes.
    There are some key differences between the operation of military 
and non-military vessels, which make the likelihood of a military 
vessel striking a whale lower than some other vessels (e.g., commercial 
merchant vessels). Key differences include:
     Many military ships have their bridges positioned closer 
to the bow, offering better visibility ahead of the ship (compared to a 
commercial merchant vessel);
     There are often aircraft associated with the training or 
testing activity (which can serve as Lookouts), which can more readily 
detect cetaceans in the vicinity of a vessel or ahead of a vessel's 
present course before crew on the vessel would be able to detect them;
     Military ships are generally more maneuverable than 
commercial merchant vessels, and if cetaceans are spotted in the path 
of the ship, could be capable of changing course more quickly;
     The crew size on military vessels is generally larger than 
merchant ships, allowing for stationing more trained Lookouts on the 
bridge. At all times when Navy vessels are underway, trained Lookouts 
and bridge navigation teams are used to detect objects on the surface 
of the water ahead of the ship, including cetaceans. Additional 
Lookouts, beyond those already stationed on the bridge and on 
navigation teams, are positioned as Lookouts during some training 
events; and
     When submerged, submarines are generally slow moving (to 
avoid detection) and therefore marine mammals at depth with a submarine 
are likely able to avoid collision with the submarine. When a submarine 
is transiting on the surface, there are Lookouts serving the same 
function as they do on surface ships.
    While there have been vessel strikes documented with commercial 
vessels, NMFS has no documented vessel strikes of marine mammals by the 
Navy in the PMSR Study Area since the Navy started keeping records of 
ship strike in 1995. The only large Navy vessels homebased in the PMSR 
local area (Port Hueneme) are the Self Defense Test Ship and the Mobile 
Ship Target, which are both greater than 200 ft in length. There are 
smaller vessels used either as targets or for target recovery as well. 
The majority of Navy vessels (e.g., LCS, destroyers) used during 
testing and training on the PMSR Study Area transit from San Diego Navy 
bases and typically transit further offshore and enter/exit the PMSR 
Study Area from

[[Page 37811]]

the southwestern boundaries to avoid commercial vessel traffic in and 
out of the Ports or Los Angeles/Long Beach via the Santa Barbara 
Channel.
    The Navy transits at safer speeds and has other protective measures 
in place during transits, such as using Lookouts and maintaining safe 
distances from marine mammals (e.g., 500 yd (457.2 m) for whales and 
200 yd (182.88 m) around other marine mammals except bow-riding 
dolphins and pinnipeds hauled out on man-made navigational structures, 
port structures, and vessels). A DoD funded study (Mintz, 2016) on 
commercial and military vessel traffic in Southern California found 
that median vessel speed for Navy vessels in the Santa Barbara Channel 
and nearshore areas of the PMSR Study Area and SOCAL (part of the HSTT 
Study Area) was between 3 to 8 knots. Speed increased as vessels 
transited further offshore, between 10-16 knots, with the higher value 
on the furthest offshore areas of the PMSR Study Area. Commercial 
tankers and cargo median vessel speeds were between 8-14 knots for the 
same nearshore areas. Mintz (2016) indicated that Navy vessels make up 
only 4 percent of the overall vessel traffic off Southern California 
(PMSR/SOCAL). The data collected for Mintz (2016) was collected via AIS 
for commercial vessel data and SeaLink for military vessels (a 
classified Navy/Coast Guard database maintained by the Office of Naval 
Intelligence). The median surface speed of two of the classes of 
vessels used on the PMSR Study Area from 2011 through 2015 was below 12 
knots. This median speed includes those training and testing operations 
that require elevated speeds, and being slightly above 10 knots, 
indicates that Naval vessels typically operate at speeds that would be 
expected to reduce the potential of vessel strike of a marine mammal.
    The Navy has several standard operating procedures for vessel 
safety that could result in a secondary benefit to marine mammals 
through a reduction in the potential for vessel strike. For example, 
ships operated by or for the Navy have personnel assigned to stand 
watch at all times, day and night, when moving through the water (i.e., 
when the vessel is underway). Watch personnel undertake extensive 
training in accordance with the U.S. Navy Lookout Training Handbook or 
civilian equivalent. A primary duty of watch personnel is to ensure 
safety of the ship, which includes the requirement to detect and report 
all objects and disturbances sighted in the water that may be 
indicative of a threat to the ship and its crew, such as debris, a 
periscope, surfaced submarine, or surface disturbance. Per safety 
requirements, watch personnel also report any marine mammals sighted 
that have the potential to be in the direct path of the ship, as a 
standard collision avoidance procedure. Navy vessels are required to 
operate in accordance with applicable navigation rules. These rules 
require that vessels proceed at a safer speed so proper and effective 
action can be taken to avoid collision and so vessels can be stopped 
within a distance appropriate to the prevailing circumstances and 
conditions. In addition to complying with navigation requirements, Navy 
ships transit at speeds that are optimal for fuel conservation, to 
maintain ship schedules, and to meet mission requirements. Vessel 
captains use the totality of the circumstances to ensure the vessel is 
traveling at appropriate speeds in accordance with navigation. This 
Navy message is also consistent with a message issued by the U.S. Coast 
Guard for vessels operating in the 11th district (covering the waters 
in and around the PMSR) as a Notice to Mariners that also informs 
operators about the presence of populations of blue, humpback, and fin 
whales in the area (see U.S. Coast Guard (2019) for further details).
    For more information, please see section 3.7.1.1.1 Vessels as a 
Strike Stressor in the 2020 PMSR DEIS/OEIS. Additionally, the Navy has 
fewer vessel transits than commercial entities in the PMSR Study Area. 
To put the PMSR Navy vessel operations level in perspective, Table 6 
includes an estimate of annual commercial shipping activity compared 
with vessel use in the PMSR Study Area. These annual estimates are 
representable of any given year as proposed for this rule. Navy vessels 
account for only about nine percent of the vessel traffic within the 
PMSR Study Area.
[GRAPHIC] [TIFF OMITTED] TP16JY21.003

    In addition, large Navy vessels (greater than 18 m in length) 
within the offshore areas of range complexes and testing ranges operate 
differently from commercial vessels in ways that may reduce potential 
for whale collisions. Surface ships operated by or for the Navy have 
multiple personnel assigned to stand watch at all times, when a ship or 
surfaced submarine is moving through the water (underway). A primary 
duty of personnel standing watch on surface ships is to detect and 
report all objects and disturbances sighted in the water that may 
indicate a threat to the vessel and its crew, such as debris, a 
periscope, surfaced submarine, or surface disturbance. Per vessel 
safety requirements, personnel standing watch also report any marine 
mammals sighted in the path of the vessel as a standard collision 
avoidance procedure. All vessels proceed at a safer speed so they can 
take proper and effective action to avoid a collision with any sighted 
object or disturbance, and can be stopped within a distance appropriate 
to the prevailing circumstances and conditions.
    Between 2007 and 2009, the Navy developed and distributed 
additional training, mitigation, and reporting tools to Navy operators 
to improve marine

[[Page 37812]]

mammal protection and to ensure compliance with LOA requirements. In 
2009, the Navy implemented Marine Species Awareness Training designed 
to improve effectiveness of visual observation for marine resources, 
including marine mammals. For over a decade, the Navy has implemented 
the Protective Measures Assessment Protocol software tool, which 
provides operators with notification of the required mitigation and a 
visual display of the planned training or testing activity location 
overlaid with relevant environmental data.
    The Navy does not anticipate vessel strikes and has not requested 
authorization to take marine mammals by serious injury or mortality 
within the PMSR Study Area during training and testing activities. NMFS 
agrees with the Navy's conclusions based on this qualitative analysis; 
therefore, NMFS has preliminarily determined that the Navy's decision 
not to request take authorization for vessel strike of large whales is 
supported by multiple factors, including no previous instances of 
strikes by Navy vessels in the PMSR Study Area, relatively low at-sea 
days compared to other Navy training and testing study areas, fewer 
vessels used compared to other Navy training and testing study areas, 
ways in which the larger vessels operate in the PMSR Study Area, and 
the mitigation measures that would be in place to further minimize 
potential vessel strike.
    In addition to the reasons listed above that make it unlikely that 
the Navy will hit a large whale (more maneuverable ships, larger crew, 
etc.), the following are additional reasons that vessel strike of 
dolphins and small whales is very unlikely. Dating back more than 20 
years and for as long as it has kept records, the Navy has no records 
of individuals of these groups being struck by a vessel as a result of 
Navy activities and, further, their smaller size and maneuverability 
make a strike unlikely. Also, NMFS has never received any reports from 
other authorized activities indicating that these species have been 
struck by vessels. Worldwide ship strike records show little evidence 
of strikes of these groups from the shipping sector and larger vessels, 
and the majority of the Navy's activities involving faster-moving 
vessels (that could be considered more likely to hit a marine mammal) 
are located in offshore areas where smaller delphinid densities are 
lower. Based on this information, NMFS concurs with the Navy's 
assessment that vessel strike is not likely to occur for either large 
whales or smaller marine mammals.

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 do not anticipate that the Navy's proposed activities 
would result in permanent effects on the habitats used by the marine 
mammals in the PMSR Study Area, 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, this 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 notice.
    Effects to Prey--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.
    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; Mann, 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 author's 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

[[Page 37813]]

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 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 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; O'Keeffe, 1984; 
O'Keeffe and Young, 1984; 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).
    Fish not killed or driven from a location by an explosion might 
change their behavior, feeding pattern, or distribution. Changes in 
behavior of fish have been observed as a result of sound produced by 
explosives, with effect intensified in areas of hard substrate (Wright, 
1982). However, Navy would avoid hard substrate to the best extent 
practical in the course of their activities. 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, 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. Long-term consequences for fish 
populations, including key prey species within the PMSR Study Area, 
would not be expected.
    Vessels and in-water devices do not normally collide with adult 
fish, most of which can detect and avoid them. Exposure of fishes to 
vessel strike stressors is limited to those fish groups that are large, 
slow-moving, and may occur near the surface, such as ocean sunfish, 
whale sharks, basking sharks, and manta rays. These species are 
distributed widely in offshore portions of the PMSR Study Area. Any 
isolated cases of a Navy vessel striking an individual could injure 
that individual, impacting the fitness of an individual fish. Vessel 
strikes would not pose a risk to most of the other marine fish groups, 
because many fish can detect and avoid vessel movements, making strikes 
rare and allowing the fish to return to their normal behavior after the 
ship or device passes. As a vessel approaches a fish, they could have a 
detectable behavioral or physiological response (e.g., swimming away 
and increased heart rate) as the passing vessel displaces them. 
However, such reactions are not expected to have lasting effects on the 
survival, growth, recruitment, or reproduction of these marine fish 
groups at the population level and therefore would not have an impact 
on marine mammal species as prey items.
    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., 2017b). 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 is a likely cause 
of zooplankton mortality (Bickel et al., 2011). The localized and 
short-term exposure to at or near the surface explosions or vessels 
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. Long-term consequences to marine invertebrate 
populations would not be expected as a result of exposure to sounds of 
vessels in the PMSR Study Area.
    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 sound exposure, explosions, vessel 
strikes, 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 PMSR Study Area.
    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 for Navy training 
and testing purposes (as in the use of explosives, and target and 
missile launches on SNI). 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

[[Page 37814]]

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, e.g., Barber et al., 2009; 
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 or from launched targets and missiles produced during 
training and testing activities as they would be more widely dispersed 
or concentrated in small areas for shorter periods of time. 
Anthropogenic noise attributable to Navy testing and training 
activities in the PMSR Study Area emanates from multiple sources 
including explosives, vessels, and launched targets and missiles 
occurring in the vicinity of pinniped haul out sites. Sound produced 
from training and testing activities in the PMSR Study Area would be 
temporary and transitory; the affected area would be expected to 
immediately return to the original state when these activities cease.
    Water Quality--Training and testing activities may introduce water 
quality constituents into the water column. Based on the analysis of 
the 2020 PMSR DSEIS/OEIS, military expended materials (e.g., 
undetonated explosive materials) would be released in quantities and at 
rates that would not result in a violation of any water quality 
standard or criteria. NMFS has reviewed this analysis and concurs that 
it reflects the best available science. High-order explosions consume 
most of the explosive material, creating typical combustion products. 
For example, in the case of the Royal Demolition Explosive, 98 percent 
of the products are common seawater constituents and the remainder is 
rapidly diluted below threshold effect level. Explosion by-products 
associated with high order detonations present no secondary stressors 
to marine mammals through sediment or water. However, low order 
detonations and unexploded ordnance present elevated likelihood of 
impacts on marine mammals.
    Indirect effects of explosives and unexploded ordnance to marine 
mammals via sediment is possible in the immediate vicinity of the 
ordnance. Degradation products of the Royal Demolition Explosive are 
not toxic to marine organisms at realistic exposure levels (Rosen and 
Lotufo, 2010). Relatively low solubility of most explosives and their 
degradation products means that concentrations of these contaminants in 
the marine environment are relatively low and readily diluted. 
Furthermore, while explosives and their degradation products were 
detectable in marine sediment approximately 6-12 in (0.15-0.3 m) away 
from degrading ordnance, the concentrations of these compounds were not 
statistically distinguishable from background beyond 3-6 ft (1-2 m) 
from the degrading ordnance. Taken together, it is possible that marine 
mammals could be exposed to degrading explosives, but it would be 
within a very small radius of the explosive (1-6 ft (0.3-2 m)).
    Equipment used by the Navy within the PMSR Study Area, including 
ships and other marine vessels, aircraft, and other equipment, are also 
potential sources of by-products. All equipment is properly maintained 
in accordance with applicable Navy and legal requirements. All such 
operating equipment meets Federal water quality standards, where 
applicable.
    Airborne Launch Sounds on SNI--Various beaches around SNI are used 
by pinnipeds as places to rest, molt, and breed. These beaches consist 
of sand (e.g., Red Eye Beach), rock ledges (e.g., Phoca Reef), and 
rocky cobble (e.g., Bachelor Beach). Pinnipeds continue to use beaches 
around the western end of SNI, and indeed are expanding their use of 
some beaches despite ongoing launch activities for many years. 
Similarly, it appears that sounds from prior launches have not affected 
pinniped use of coastal areas at VAFB.
    Pinnipeds forage in the open ocean and in the waters near SNI; 
however, the airborne launch sounds would not persist in the water near 
SNI. Therefore, it is not expected that the launch activities would 
impact prey resources, Essential Fish Habitat (EFH), or feeding success 
of pinnipeds. Three types of EFH are present in the activity area: 
Groundfish, coastal pelagic species, and highly migratory species, as 
well as canopy kelp Habitat Areas of Particular Concern (HAPC). 
However, none of these types of EFH or HAPC will be impacted by the 
proposed activity.
    Boosters from missiles (e.g., jet-assisted take off rocket bottles 
for BQM drone missiles) may be jettisoned shortly after launch and fall 
on the island and would be collected, but are not expected to impact 
beaches. Fuel contained in these boosters is consumed rapidly and 
completely, so there would be no risk of contamination even in the very 
unlikely event that a booster did land on a beach or nearshore waters. 
Overall, the proposed missile launch activity is not expected to cause 
significant impacts or have permanent, adverse effects on pinniped 
habitats or on their foraging habitats and prey.

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 coordinated closely 
with the Navy in the development of their incidental take application, 
and preliminarily agrees that the methods the Navy 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 and 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.
    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;

[[Page 37815]]

and (4) the number of days of activities or events.

Acoustic Thresholds

    Using the best available science, NMFS, in coordination with the 
Navy, has established acoustic thresholds that identify the most 
appropriate received level of underwater sound above which marine 
mammals exposed to these sound sources could be reasonably expected to 
directly experience a disruption in behavior patterns to a point where 
they are abandoned or significantly altered, to incur TTS (equated to 
Level B harassment), or to incur PTS of some degree (equated to Level A 
harassment). Thresholds have also been developed to identify the 
pressure levels above which animals may incur non-auditory injury from 
exposure to pressure waves from explosive detonation. Refer to the 
Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects 
Analysis (Phase III) report (U.S. Department of the Navy, 2017c) for 
detailed information on how the criteria and thresholds were derived.
    Despite the quickly evolving science, there are still challenges in 
quantifying expected behavioral responses that qualify as take by Level 
B harassment, especially where the goal is to use one or two 
predictable indicators (e.g., received level and distance) to predict 
responses that are also driven by additional factors that cannot be 
easily incorporated into the thresholds (e.g., context). So, while the 
behavioral harassment thresholds have been refined here to better 
consider the best available science (e.g., incorporating both received 
level and distance), they also still have some built-in conservative 
factors to address the challenge noted. For example, while duration of 
observed responses in the data are now considered in the thresholds, 
many of the responses that are informing take thresholds are of a very 
short duration, such that it is possible that responses will not rise 
to the level of disrupting behavior patterns to a point where they are 
abandoned or significantly altered. We describe the application of this 
behavioral harassment threshold as identifying the maximum number of 
instances in which marine mammals could be reasonably expected to 
experience a disruption in behavior patterns to a point where they are 
abandoned or significantly altered. In summary, we believe these 
behavioral harassment thresholds are the most appropriate method for 
predicting Level B harassment by behavioral disturbance given the best 
available science and the associated uncertainty.
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 Navy's proposed 
activity only includes the use of impulsive (explosives) sources. These 
thresholds (Table 7) were developed by compiling and synthesizing the 
best available science and soliciting input multiple times from both 
the public and peer reviewers. The references, analysis, and 
methodology used in the development of the thresholds are described in 
Acoustic Technical Guidance, which may be accessed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
    Based on the best available science, the Navy (in coordination with 
NMFS) used the acoustic and pressure thresholds indicated in Table 7 to 
predict the onset of TTS, PTS, tissue damage, and mortality for 
explosives (impulsive) and other impulsive sound sources.

            Table 7--Onset of TTS, PTS, Tissue Damage, and Mortality Thresholds for Marine Mammals for Explosives and Other Impulsive Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                               Mean onset slight   Mean onset slight      Mean onset
    Functional hearing group            Species            Onset TTS           Onset PTS        GI tract injury       lung injury          mortality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans.........  All mysticetes....  168 dB SEL          183 dB SEL          237 dB Peak SPL...  Equation 1........  Equation 2
                                                       (weighted) or 213   (weighted). or
                                                       dB Peak SPL.        219 dB Peak SPL.
Mid-frequency cetaceans.........  Most delphinids,    170 dB SEL          185 dB SEL          237 dB Peak SPL...
                                   medium and large    (weighted) or 224   (weighted) or 230
                                   toothed whales.     dB Peak SPL.        dB Peak SPL.
High-frequency cetaceans........  Porpoises and       140 dB SEL          155 dB SEL          237 dB Peak SPL...
                                   Kogia spp.          (weighted) or 196   (weighted) or 202
                                                       dB Peak SPL.        dB Peak SPL.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
Equation 1: 47.5M1/3 (1+[DRm/10.1])1/6 Pa-sec.
Equation 2: 103M1/3 (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.
    The mitigation measures associated with explosives are expected to 
be effective in preventing non-auditory tissue damage to any 
potentially affected species, and when considered in combination with 
the modeled

[[Page 37816]]

exposure results, no species are anticipated to incur non-auditory 
tissue damage during the period of this rule. Table 16 indicates the 
range of effects for tissue damage for different explosive types. The 
Navy will implement mitigation measures (described in the Proposed 
Mitigation Measures section) during explosive activities, including 
delaying detonations when a marine mammal is observed in the mitigation 
zone. Nearly all explosive events will occur during daylight hours to 
improve the sightability of marine mammals and thereby improve 
mitigation effectiveness. Observing for marine mammals during the 
explosive activities will include visual methods before the activity 
begins, in order to cover the mitigation zone (e.g., 2,500 yds (2,286 
m) for explosive bombs).
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 8 below and Table 7 for the TTS 
thresholds for explosives) for events that contain multiple impulses 
from explosives underwater. This was the same approach as taken in 
Phase II and Phase III for explosive analysis in other Navy training 
and testing Study Areas. 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 5dB higher than the 
behavioral harassment threshold for multiple explosives.

Table 8--Thresholds for Level B Harassment by Behavioral Disturbance for
                      Explosives for Marine Mammals
------------------------------------------------------------------------
                                     Functional hearing
              Medium                        group         SEL (weighted)
------------------------------------------------------------------------
Underwater........................  LF..................             163
Underwater........................  MF..................             165
Underwater........................  HF..................             135
Underwater........................  Otariids............             183
Underwater........................  Phocids.............             165
------------------------------------------------------------------------
Note: Weighted SEL thresholds in dB re 1 [mu]Pa\2\s underwater. LF = low-
  frequency, MF = mid-frequency, HF = high-frequency.

Navy's Acoustic Effects Model

    The Navy's Acoustic Effects Model calculates sound energy 
propagation from sonar and other transducers and explosives during 
naval activities and the sound received by animat dosimeters. Animat 
dosimeters are virtual representations of marine mammals distributed in 
the area around the modeled naval activity and each dosimeter records 
its individual sound ``dose.'' The model bases the distribution of 
animats over the PMSR Study Area on the density values in the Navy 
Marine Species Density Database and distributes animats in the water 
column proportional to the known time that species spend at varying 
depths.
    The model accounts for environmental variability of sound 
propagation in both distance and depth when computing the received 
sound level received by the animats. The model conducts a statistical 
analysis based on multiple model runs to compute the estimated effects 
on animals. The number of animats that exceed the thresholds for 
effects is tallied to provide an estimate of the number of marine 
mammals that could be affected.
    Assumptions in the Navy model intentionally err on the side of 
overestimation when there are unknowns. Naval activities are modeled as 
though they would occur regardless of proximity to marine mammals, 
meaning that no mitigation is considered and without any avoidance of 
the activity by the animal. The final step of the quantitative analysis 
of acoustic effects is to consider the implementation of mitigation and 
the possibility that marine mammals would avoid continued or repeated 
sound exposures. For more information on this process, see the 
discussion in the Take Estimation subsection below. Many explosions 
from ordnance such as bombs and missiles actually occur upon impact 
with above-water targets. However, for this analysis, sources such as 
these were modeled as exploding underwater, which overestimates the 
amount of explosive and acoustic energy entering the water.
    The model estimates the impacts caused by individual training and 
testing exercises. During any individual modeled event, impacts to 
individual animats are considered over 24-hour periods. The animats do 
not represent actual animals, but rather a distribution of animals 
based on density and abundance data, which allows for a statistical 
analysis of the number of instances that marine mammals may be exposed 
to sound levels resulting in an effect. Therefore, the model estimates 
the number of instances in which an effect threshold was exceeded over 
the course of a year, but does not estimate the number of individual 
marine mammals that may be impacted over a year (i.e., some marine 
mammals could be impacted several times, while others would not 
experience any impact). A detailed explanation of the Navy's Acoustic 
Effects Model is provided in the technical report Quantifying Acoustic 
Impacts on Marine Species: Methods and Analytical Approach for 
Activities at the Point Mugu Sea Range (U.S. Department of the Navy, 
2020).

Range to Effects

    The following section provides range (distance) to effects for 
explosives, to specific acoustic thresholds determined using the Navy 
Acoustic Effects Model. Marine mammals exposed within these ranges for 
the shown duration are predicted to experience the associated effect. 
Range to effects is important information in not only predicting 
acoustic impacts, but also in verifying the accuracy of model results 
against real-world situations and determining adequate mitigation 
ranges to avoid higher level effects, especially

[[Page 37817]]

physiological effects to marine mammals.

Explosives

    The following section provides the range (distance) over which 
specific physiological or behavioral effects are expected to occur 
based on the explosive criteria (see Section 6, Section 6.5.2.1.1 of 
the Navy's rulemaking/LOA application and the Criteria and Thresholds 
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III) 
report (U.S. Department of the Navy, 2017c)) and the explosive 
propagation calculations from the Navy Acoustic Effects Model (see 
Section 6, Section 6.5.2.1.3, Navy Acoustic Effects Model of the Navy's 
rulemaking/LOA application). The range to effects is shown for a range 
of explosive bins, from E1 (up to 0.25 lb net explosive weight) to E10 
(up to 500 lb net explosive weight) (Tables 11 through 17). Explosive 
bins not shown on these tables include E2, E4, E7, E11, and E12, as 
they are not used in the PMSR Study Area and therefore not included in 
Tables 11 through 17. Ranges are determined by modeling the distance 
that noise from an explosion would need to propagate to reach exposure 
level thresholds specific to a hearing group that would cause 
behavioral response (to the degree of Level B harassment), TTS, PTS, 
and non-auditory injury. Ranges are provided for a representative 
source depth and cluster size for each bin. For events with multiple 
explosions, sound from successive explosions can be expected to 
accumulate and increase the range to the onset of an impact based on 
SEL thresholds. Ranges to non-auditory injury and mortality are shown 
in Tables 16 and 17, respectively. NMFS has reviewed the range distance 
to effect data provided by the Navy and concurs with the analysis. For 
additional information on how ranges to impacts from explosions were 
estimated, see the technical report Quantifying Acoustic Impacts on 
Marine Species: Methods and Analytical Approach for Activities at the 
Point Mugu Sea Range (U.S. Department of the Navy, 2020).
    Table 11 shows the minimum, average, and maximum ranges to onset of 
auditory and behavioral effects that likely rise to the level of Level 
B harassment for high-frequency cetaceans based on the developed 
thresholds.

  Table 11--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance
                                          for High-Frequency Cetaceans
----------------------------------------------------------------------------------------------------------------
              Bin                Cluster size            PTS                   TTS               Behavioral
----------------------------------------------------------------------------------------------------------------
E1............................               1         353 (130-825)     1,234 (290-3,025)     2,141 (340-4,775)
                                            25     1,188 (280-3,025)     3,752 (490-8,525)    5,196 (675-12,275)
E3............................               1       654 (220-1,525)     2,294 (350-4,775)     3,483 (490-7,775)
                                            12     1,581 (300-3,525)    4,573 (650-10,275)    6,188 (725-14,775)
E5............................              25     2,892 (440-6,275)    6,633 (725-16,025)    8,925 (800-22,775)
E6............................               1     1,017 (280-2,525)     3,550 (490-7,775)    4,908 (675-12,275)
E8............................               1     1,646 (775-2,525)   4,322 (1,525-9,775)  5,710 (1,525-14,275)
E9............................               1     2,105 (850-4,025)  4,901 (1,525-12,525)  6,700 (1,525-16,775)
E10...........................               1     2,629 (875-5,275)  5,905 (1,525-13,775)  7,996 (1,525-20,025)
----------------------------------------------------------------------------------------------------------------
\1\Average distance in meters is depicted above the minimum and maximum distances, which are in parentheses.
Notes: SEL = Sound Exposure Level, PTS = permanent threshold shift, TTS = temporary threshold shift.

    Table 12 shows the minimum, average, and maximum ranges to onset of 
auditory and behavioral effects that likely rise to the level of Level 
B harassment for mid-frequency cetaceans based on the developed 
thresholds.

  Table 12--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance
                                           for Mid-Frequency Cetaceans
----------------------------------------------------------------------------------------------------------------
              Bin                Cluster Size            PTS                   TTS               Behavioral
----------------------------------------------------------------------------------------------------------------
E1............................               1            25 (25-25)          118 (80-210)         178 (100-320)
                                            25          107 (75-170)       476 (150-1,275)       676 (240-1,525)
E3............................               1            50 (45-65)         233 (110-430)         345 (130-600)
                                            12          153 (90-250)       642 (220-1,525)       897 (270-2,025)
E5............................              25         318 (130-625)     1,138 (280-3,025)     1,556 (310-3,775)
E6............................               1           98 (70-170)         428 (150-800)       615 (210-1,525)
E8............................               1         160 (150-170)         676 (500-725)       942 (600-1,025)
E9............................               1         215 (200-220)         861 (575-950)     1,147 (650-1,525)
E10...........................               1         275 (250-480)     1,015 (525-2,275)     1,424 (675-3,275)
----------------------------------------------------------------------------------------------------------------
\1\Average distance in meters to mortality is depicted above the minimum and maximum distances, which are in
  parentheses.
Notes: SEL = Sound Exposure Level, PTS = permanent threshold shift, TTS = temporary threshold shift.

    Table 13 shows the minimum, average, and maximum ranges to onset of 
auditory and behavioral effects that likely rise to the level of Level 
B harassment for low-frequency cetaceans based on the developed 
thresholds.

  Table 13--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance
                                           for Low-Frequency Cetaceans
----------------------------------------------------------------------------------------------------------------
              Bin                Cluster size            PTS                   TTS               Behavioral
----------------------------------------------------------------------------------------------------------------
E1............................               1            51 (40-70)         227 (100-320)          124 (70-160)
                                            25          205 (95-270)       772 (270-1,275)         476 (190-725)

[[Page 37818]]

 
E3............................               1          109 (65-150)       503 (190-1,000)         284 (120-430)
                                            12         338 (130-525)     1,122 (320-7,775)       761 (240-6,025)
E5............................              25       740 (220-6,025)    2,731 (460-22,275)    1,414 (350-14,275)
E6............................               1         250 (100-420)       963 (260-7,275)       617 (200-1,275)
E8............................               1         460 (170-950)     1,146 (380-7,025)       873 (280-3,025)
E9............................               1       616 (200-1,275)    1,560 (450-12,025)     1,014 (330-5,025)
E10...........................               1       787 (210-2,525)    2,608 (440-18,275)     1,330 (330-9,025)
----------------------------------------------------------------------------------------------------------------
\1\Average distance in meters to mortality is depicted above the minimum and maximum distances, which are in
  parentheses.
Notes: SEL = Sound Exposure Level, PTS = permanent threshold shift, TTS = temporary threshold shift.


  Table 14--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance
                                                  for Otariids
----------------------------------------------------------------------------------------------------------------
              Bin                Cluster size            PTS                   TTS               Behavioral
----------------------------------------------------------------------------------------------------------------
E1............................               1               7 (7-7)            34 (30-40)            56 (45-70)
                                            25            30 (25-35)          136 (80-180)         225 (100-320)
                                            10            25 (25-30)          115 (70-150)          189 (95-250)
E3............................               1            16 (15-19)            70 (50-95)          115 (70-150)
                                            12            45 (35-65)         206 (100-290)         333 (130-450)
                                            12            55 (50-60)         333 (280-750)       544 (440-1,025)
E5............................              25           98 (60-120)         418 (160-575)       626 (240-1,000)
E6............................               1            30 (25-35)          134 (75-180)         220 (100-320)
E8............................               1            50 (50-50)         235 (220-250)         385 (330-450)
E9............................               1            68 (65-70)         316 (280-360)         494 (390-625)
E10...........................               1            86 (80-95)         385 (240-460)         582 (390-800)
----------------------------------------------------------------------------------------------------------------
\1\Average distance in meters to mortality is depicted above the minimum and maximum distances, which are in
  parentheses.
Notes: SEL = Sound Exposure Level, PTS = permanent threshold shift, TTS = temporary threshold shift.


  Table 15--SEL-Based Ranges (Meters) to Onset PTS, Onset TTS, and Level B Harassment by Behavioral Disturbance
                                                   for Phocids
----------------------------------------------------------------------------------------------------------------
              Bin                Cluster size            PTS                   TTS               Behavioral
----------------------------------------------------------------------------------------------------------------
E1............................               1            45 (40-65)         210 (100-290)         312 (130-430)
                                            25          190 (95-260)       798 (280-1,275)     1,050 (360-2,275)
E2............................               1            58 (45-75)         258 (110-360)         383 (150-550)
                                            10          157 (85-240)       672 (240-1,275)       934 (310-1,525)
E3............................               1           96 (60-120)         419 (160-625)         607 (220-900)
                                            12         277 (120-390)     1,040 (370-2,025)     1,509 (525-6,275)
E5............................              25         569 (200-850)     2,104 (725-9,275)    2,895 (825-11,025)
E6............................               1          182 (90-250)       767 (270-1,275)     1,011 (370-1,775)
E8............................               1         311 (290-330)     1,154 (625-1,275)     1,548 (725-2,275)
E9............................               1         416 (350-470)     1,443 (675-2,025)     1,911 (800-3,525)
E10...........................               1         507 (340-675)     1,734 (725-3,525)     2,412 (800-5,025)
----------------------------------------------------------------------------------------------------------------
\1\ Average distance (in meters) to PTS, TTS, and behavioral thresholds are depicted above the minimum and
  maximum distances, which are in parentheses. Values depict the range produced by SEL hearing threshold
  criteria levels.
Notes: SEL = Sound Exposure Level, PTS = permanent threshold shift, TTS = temporary threshold shift.

    Table 16 shows the minimum, average, and maximum ranges due to 
varying propagation conditions to non-auditory injury as a function of 
animal mass and explosive bin (i.e., net explosive weight). Ranges to 
gastrointestinal tract injury typically exceed ranges to slight lung 
injury; therefore, the maximum range to effect is not mass-dependent. 
Animals within these water volumes would be expected to receive minor 
injuries at the outer ranges, increasing to more substantial injuries, 
and finally mortality as an animal approaches the detonation point.

Table 16--Ranges 1 to 50 Percent Non-Auditory Injury Risk for All Marine
                          Mammal Hearing Groups
------------------------------------------------------------------------
                                                         Range (m) (min-
                          Bin                                 max)
------------------------------------------------------------------------
E1....................................................        12 (11-13)
E3....................................................        25 (25-30)
E5....................................................       40 (35-140)
E6....................................................       52 (40-120)
E8....................................................      117 (75-400)
E9....................................................      120 (90-290)
E10...................................................     174 (100-480)
------------------------------------------------------------------------
Note: All ranges to non-auditory injury within this table are driven by
  the gastrointestinal (GI) tract injury threshold regardless of animal
  mass.

    Ranges to mortality, based on animal mass, are shown in Table 17 
below.

[[Page 37819]]



                    Table 17--Ranges 1 to 50 Percent Mortality Risk for All Marine Mammal Hearing Groups as a Function of Animal Mass
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Animal mass intervals (kg) \1\
                           Bin                           -----------------------------------------------------------------------------------------------
                                                                10              250            1,000           5,000          25,000          72,000
--------------------------------------------------------------------------------------------------------------------------------------------------------
E1......................................................         3 (2-3)         0 (0-3)         0 (0-0)         0 (0-0)         0 (0-0)         0 (0-0)
E3......................................................        8 (6-10)         4 (2-8)         1 (0-2)         0 (0-0)         0 (0-0)         0 (0-0)
E5......................................................      13 (11-45)        7 (4-35)        3 (3-12)         2 (0-8)         0 (0-2)         0 (0-2)
E6......................................................      18 (14-55)       10 (5-45)        5 (3-15)        3 (2-10)         0 (0-3)         0 (0-2)
E8......................................................     50 (24-110)       27 (9-55)       13 (0-20)        9 (4-13)         4 (0-6)         3 (0-5)
E9......................................................      32 (30-35)      20 (13-30)       10 (8-12)         7 (6-9)         4 (3-4)         3 (2-3)
E10.....................................................     56 (40-190)     25 (16-130)      13 (11-16)        9 (7-11)         5 (4-5)         4 (3-4)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Average distance (m) to mortality is depicted above the minimum and maximum distances, which are in parentheses.

Marine Mammal Density

    A quantitative analysis of impacts on a species or stock requires 
data on their abundance and distribution that may be affected by 
anthropogenic activities in the potentially impacted area. The most 
appropriate metric for this type of analysis is density, which is the 
number of animals present per unit area. Marine species density 
estimation requires a significant amount of effort to both collect and 
analyze data to produce a reasonable estimate. Unlike surveys for 
terrestrial wildlife, many marine species spend much of their time 
submerged, and are not easily observed. In order to collect enough 
sighting data to make reasonable density estimates, multiple 
observations are required, often in areas that are not easily 
accessible (e.g., far offshore). Ideally, marine mammal species 
sighting data would be collected for the specific area and time period 
(e.g., season) of interest and density estimates derived accordingly. 
However, in many places, poor weather conditions and high sea states 
prohibit the completion of comprehensive visual surveys.
    For most cetacean species, abundance is estimated using line-
transect surveys or mark-recapture studies (e.g., Barlow, 2016, 2010; 
Barlow and Forney, 2007; Calambokidis et al., 2008; Calambokidis and 
Barlow, 2020; Cooke, 2019; Forney et al., 2014; Trickey et al., 2020). 
The result provides one single density estimate value for each species 
across broad geographic areas. This is the general approach applied in 
estimating cetacean abundance in NMFS' SARs. Although the single value 
provides a good average estimate of abundance (total number of 
individuals) for a specified area, it does not provide information on 
the species distribution or concentrations within that area, and it 
does not estimate density for other timeframes or seasons that were not 
surveyed. More recently, spatial habitat modeling developed by NMFS' 
Southwest Fisheries Science Center has been used to estimate cetacean 
densities (Barlow et al., 2009, 2020; Becker et al., 2010, 2012a, b, c, 
2014, 2016; Ferguson et al., 2006a; Forney et al., 2012, 2015; Redfern 
et al., 2006; Rockwood et al., 2020). These models estimate cetacean 
density as a continuous function of habitat variables (e.g., sea 
surface temperature, seafloor depth, etc.) and thus allow predictions 
of cetacean densities on finer spatial scales than traditional line-
transect or mark recapture analyses and for areas that have not been 
surveyed. Within the geographic area that was modeled, densities can be 
predicted wherever these habitat variables can be measured or 
estimated.
    To characterize marine species density for large oceanic regions, 
the Navy reviews, critically assesses, and prioritizes existing density 
estimates from multiple sources, requiring the development of a 
systematic method for selecting the most appropriate density estimate 
for each combination of species, area, and season. The selection and 
compilation of the best available marine species density data resulted 
in the Navy Marine Species Density Database (NMSDD) (U.S. Department of 
the Navy, 2017). The finest temporal resolution (seasonal) for the 
NMSDD data for the HSTT Study Area was also used for the PMSR Study 
Area. The Navy vetted all cetacean densities with NMFS prior to use in 
the Navy's acoustic analysis for this proposed rulemaking.
    A variety of density data and density models are needed in order to 
develop a density database that encompasses the entirety of the PMSR 
Study Area. Because these data are collected using different methods 
with varying amounts of accuracy and uncertainty, the Navy has 
developed a hierarchy to ensure the most accurate data is used when 
available. The technical report titled Quantifying Acoustic Impacts on 
Marine Species: Methods and Analytical Approach for Activities at the 
Point Mugu Sea Range (U.S. Department of the Navy, 2020), hereafter 
referred to as the Density Technical Report, describes these models in 
detail and provides detailed explanations of the models applied to each 
species density estimate. The list below describes models in order of 
preference.
    1. Spatial density models are preferred and used when available 
because they provide an estimate with the least amount of uncertainty 
by deriving estimates for divided segments of the sampling area. These 
models (see Becker et al., 2016; Forney et al., 2015) predict spatial 
variability of animal presence as a function of habitat variables 
(e.g., sea surface temperature, seafloor depth, etc.). This model is 
developed for areas, species, and, when available, specific timeframes 
(months or seasons) with sufficient survey data; therefore, this model 
cannot be used for species with low numbers of sightings.
    2. Stratified design-based density estimates use line-transect 
survey data with the sampling area divided (stratified) into sub-
regions, and a density is predicted for each sub-region (see Barlow, 
2016; Becker et al., 2016; Bradford et al., 2017; Campbell et al., 
2014; Jefferson et al., 2014). While geographically stratified density 
estimates provide a better indication of a species' distribution within 
the study area, the uncertainty is typically high because each sub-
region estimate is based on a smaller stratified segment of the overall 
survey effort.
    3. Design-based density estimations use line-transect survey data 
from land and aerial surveys designed to cover a specific geographic 
area (see Carretta et al., 2015). These estimates use the same survey 
data as stratified design-based estimates, but are not segmented into 
sub-regions and instead provide one estimate for a large surveyed area. 
Although relative environmental suitability (RES) models provide 
estimates for areas of the oceans that have not been surveyed using

[[Page 37820]]

information on species occurrence and inferred habitat associations and 
have been used in past density databases, these models were not used in 
the current quantitative analysis.
    Below we describe how densities were determined for the species in 
the PMSR Study Area.
    The Navy developed a protocol and database to select the best 
available data sources based on species, area, and time (season). The 
resulting Geographic Information System database, used in the NMSDD, 
includes seasonal density values for every marine mammal species 
present within the PMSR Study Area. This database is described in the 
Quantifying Acoustic Impacts on Marine Species: Methods and Analytical 
Approach for Activities at the Point Mugu Sea Range (U.S. Department of 
the Navy, 2020) (also referred to as the Density Technical Report in 
this rule).
    The Navy describes some of the challenges of interpreting the 
results of the quantitative analysis summarized above and described in 
the Density Technical Report: ``It is important to consider that even 
the best estimate of marine species density is really a model 
representation of the values of concentration where these animals might 
occur. Each model is limited to the variables and assumptions 
considered by the original data source provider. No mathematical model 
representation of any biological population is perfect, and with 
regards to marine mammal density, any single model method will not 
completely explain the actual distribution and abundance of marine 
mammal species. It is expected that there would be anomalies in the 
results that need to be evaluated, with independent information for 
each case, to support if we might accept or reject a model or portions 
of the model (U.S. Department of the Navy, 2017a).'' There was only one 
species, the harbor porpoise, where there was no density estimate 
available within the PMSR Study Area so a new density layer was 
developed for harbor porpoise. Forney et al. (2014) provided uniform 
density for harbor porpoise for the species as a whole in California 
(Figure 7-25 in the Density Technical Report). Although these density 
estimates may not fully describe PMSR interannual variability, 
fluctuations in population size, or spatial distributions, they 
represent the best available science due to the paucity of other data.
    NMFS coordinated with the Navy in the development of its take 
estimates and concurs that the Navy's approach for density 
appropriately utilizes the best available science. Later, in the 
Preliminary Analysis and Negligible Impact Determination section, we 
assess how the estimated take numbers compare to abundance in order to 
better understand the potential number of individuals impacted.

Take Estimation

    The 2020 PMSR DEIS/OEIS considered all training and testing 
activities proposed to occur in the PMSR Study Area that have the 
potential to result in the MMPA-defined take of marine mammals. The 
Navy determined that the three stressors below could result in the 
incidental taking of marine mammals. NMFS has reviewed the Navy's data 
and analysis and determined that it is complete and accurate and agrees 
that the following stressors from the Navy's proposed activities have 
the potential to result in takes by harassment.
    [ssquf] Acoustics (weapons firing noise; Explosions at or near the 
water surface can introduce loud, impulsive, broadband sounds into the 
marine environment);
    [ssquf] Explosives (explosive shock wave and sound at or near the 
water surface (<10 m)); and
    [ssquf] Land-based launch noise on SNI from missiles and rocket 
launches.
    To predict marine mammal exposures to explosives, and because there 
is currently no means to model impacts on marine mammals from in-air 
detonations, the Navy's analysis conservatively models all detonations 
occurring within 10 m above the water's surface, as a point source 
located 10 centimeters underwater (U.S. Department of the Navy, 2019a). 
The model also assumes that all acoustic energy from the detonation 
remains underwater with no sound transmitted into the air. Important 
considerations must be factored into the analysis of results with these 
modeling assumptions, given that the peak pressure and sound from a 
detonation in air significantly decreases as it is partially reflected 
by the water's surface and partially transmitted underwater, as 
detailed in the following paragraphs. The Navy performed a quantitative 
analysis to estimate the probability that marine mammals could be 
exposed to the sound and energy from explosions during Navy testing and 
training activities and the effects of those exposures. 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 near the water surface would be less susceptible to 
injury because the pressure wave reflected from the water surface would 
interfere with the direct path pressure wave, reducing positive 
pressure exposure.
    The quantitative analysis process (used for the 2020 PMSR DEIS/OEIS 
and the Navy's take request in the rulemaking/LOA application) to 
estimate potential exposures to marine mammals resulting from acoustic 
and explosive stressors is detailed in the technical report titled 
Quantifying Acoustic Impacts on Marine Species: Methods and Analytical 
Approach for Activities at the Point Mugu Sea Range (U.S. Department of 
the Navy, 2020). The Navy Acoustic Effects Model (NAEMO) brings 
together scenario simulations of the Navy's activities, sound 
propagation modeling, and marine mammal distribution (based on density 
and group size) by species to model and quantify the exposure of marine 
mammals above identified thresholds for behavioral harassment, TTS, 
PTS, non-auditory injury (lung and GI), and serious injury and 
mortality.
    NAEMO estimates acoustic and explosive effects without taking 
mitigation or avoidance into account; therefore, the model 
overestimates predicted impacts on marine mammals within mitigation 
zones. The NAEMO (animal movement) model overestimates the number of 
marine mammals that would be exposed to sound sources that could cause 
PTS because the model does not consider horizontal movement of animats, 
including avoidance of high intensity sound exposures. As a general 
matter, NMFS does not prescribe the methods for estimating take for any 
applicant, but we review and ensure that applicants use the best 
available science, and methodologies that are logical and technically 
sound. Applicants may use different methods of calculating take 
(especially when using models) and still get to a result that is 
representative of the best available science and that allows for a 
rigorous and accurate evaluation of the effects on the affected 
populations. There are multiple aspects of the Navy's take estimation 
methods--propagation models, animat movement models, and behavioral 
thresholds, for example. NMFS evaluates the acceptability of these 
aspects as they evolve and are used in different rules and impact 
analyses. Some of the aspects of the Navy's take estimation process 
have been used in Navy incidental take rules since 2009 and have 
undergone multiple public comment processes; all of them have undergone 
extensive internal Navy review, and all of them have undergone 
comprehensive review by NMFS, has sometimes resulted in

[[Page 37821]]

modifications to methods or models. The Navy uses rigorous review 
processes (verification, validation, and accreditation processes, peer 
and public review) to ensure the data and methodology it uses represent 
the best available science. For instance, the NAEMO model is the result 
of a NMFS-led Center for Independent Experts (CIE) review of the 
components used in earlier models. The acoustic propagation component 
of the NAEMO model (CASS/GRAB) is accredited by the Oceanographic and 
Atmospheric Master Library (OAML), and many of the environmental 
variables used in the NAEMO model come from approved OAML databases and 
are based on in-situ data collection. The animal density components of 
the NAEMO model are base products of the NMSDD, which includes animal 
density components that have been validated and reviewed by a variety 
of scientists from NMFS Science Centers and academic institutions. 
Finally the NAEMO model simulation components underwent QA/QC review 
and validation for model parts such as the scenario builder, acoustic 
builder, scenario simulator, etc., conducted by qualified statisticians 
and modelers to ensure accuracy. Other models and methodologies have 
gone through similar review processes.
    In summary, we believe the Navy's methods, including the underlying 
NAEMO modeling, are the most appropriate methods for predicting non-
auditory injury, PTS, TTS, and behavioral disturbance. We would 
describe the application of these methods as identifying the maximum 
number of instances in which marine mammals would be reasonably 
expected to be taken through PTS, TTS, or behavioral disturbance.

Summary of Estimated Take Request From Training and Testing Activities

    Based on the methods discussed in the previous sections and the 
Navy's model, the Navy provided its take estimate and request for 
authorization of takes incidental to the use of explosive sources and 
target/missile launches for training and testing activities both 
annually (based on the maximum number of activities that could occur 
per year) and over the seven-year period covered by the Navy's 
rulemaking/LOA application. NMFS has reviewed the Navy's data, 
methodology, and analysis and determined that it is complete and 
accurate. NMFS agrees that the estimates for incidental takes by 
harassment from all sources requested for authorization are the maximum 
number of instances in which marine mammals are reasonably expected to 
be taken.
Estimated Harassment Take From Training and Testing Activities
    Tables 18 and 19 summarize the Navy's take estimate, which NMFS 
concurs with, and includes the maximum amount of Level A harassment and 
Level B harassment reasonably expected to occur by species and stock 
for explosives and missile launch activities on SNI expected annually 
and for the seven-year period.

Table 18--Proposed Annual and Seven-Year Total Species-Specific Take Estimates From Explosives for All Training and Testing Activities in the PMSR Study
                                                      Area (not inclusive of launch events on SNI)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Proposed annual take by Level A and   Proposed 7-year total take by Level A
                                                                                      Level B harassment                 and Level B harassment **
                Common name                            Stock/DPS           -----------------------------------------------------------------------------
                                                                             Behavioral                             Behavioral
                                                                              response       TTS          PTS        response       TTS          PTS
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale *...............................  Eastern North Pacific........            7            4            0           52           27            0
Bryde's whale..............................  Eastern Tropical Pacific.....            0            0            0            0            0            0
Fin whale *................................  California, Oregon, and                 14            7            1          101           46            7
                                              Washington.
Gray whale.................................  Eastern North Pacific........            9            5            0           65           37            0
                                             Western North Pacific                    0            0            0            0            0            0
                                              [dagger].
Humpback whale *...........................  California, Oregon, and                  7            4            0           52           29            0
                                              Washington/Mexico DPS.
                                             California, Oregon, and                  1            0            0            6            0            0
                                              Washington/Central America
                                              DPS.
Minke whale................................  California, Oregon, and                  2            1            0           15            6            0
                                              Washington.
Sei whale *................................  Eastern North Pacific........            0            0            0            0            0            0
Baird's beaked whale.......................  California, Oregon, and                  0            0            0            0            0            0
                                              Washington.
Bottlenose dolphin.........................  California Coastal...........            0            0            0            0            0            0
                                             California, Oregon, and                  5            5            1           37           36            4
                                              Washington Offshore.
Cuvier's beaked whale......................  California, Oregon, and                  0            0            0            0            0            0
                                              Washington.
Dall's porpoise............................  California, Oregon, and                261          406           49        1,824        2,845          341
                                              Washington.
Dwarf sperm whale..........................  California, Oregon, and                 20           31            6          142          217           43
                                              Washington.
Harbor Porpoise............................  Morro Bay....................            0            0            0            0            0            0
Killer whale...............................  Eastern North Pacific                    0            0            0            0            0            0
                                              Offshore.
                                             Eastern North Pacific                    0            0            0            0            0            0
                                              Transient or West Coast
                                              Transient \6\.
Long-beaked common dolphin.................  California...................           66           44            9          454          310           65

[[Page 37822]]

 
Mesoplodont spp............................  California, Oregon, and                  0            0            0            0            0            0
                                              Washington.
Northern right whale dolphin...............  California, Oregon, and                  3            2            1           22           16            4
                                              Washington.
Pacific white-sided dolphin................  California, Oregon, and                 11            8            2           76           58           14
                                              Washington.
Pygmy killer whale.........................  NSD..........................            0            0            0            0            0            0
Pygmy sperm whale..........................  California, Oregon, and                 20           31            6          141          219           44
                                              Washington.
Risso's dolphins...........................  California, Oregon, and                  6            3            1           39           24            6
                                              Washington.
Short-beaked common dolphin................  California, Oregon, and                 90           65           15          630          456          103
                                              Washington.
Short-finned pilot whale...................  California, Oregon, and                  0            0            0            0            0            0
                                              Washington.
Sperm whale*...............................  California, Oregon, and                  1            1            0            7            8            0
                                              Washington.
Striped dolphin............................  California, Oregon, and                  1            1            0            5            4            0
                                              Washington.
Harbor seal................................  California...................          202          120           14        1,415          842           99
Northern elephant seal.....................  California...................           37           63           22          258          444          152
California sea lion........................  U.S. Stock...................            8           12            2           58           81           16
Guadalupe fur seal*........................  Mexico to California.........            1            1            0            5            7            0
Northern fur seal..........................  California...................            0            0            0            0            0            0
--------------------------------------------------------------------------------------------------------------------------------------------------------
* ESA-listed species in PMSR.
** 7-year total impacts may differ from the annual total times seven as a result of standard rounding.
[dagger] Only the indicated DPS is ESA-listed.
Note: NSD = No stock designation.


  Table 19--Annual and Seven-Year Total Species-Specific Take Estimates Proposed From Target and Missile Launch
                                    Activities on SNI in the PMSR Study Area
----------------------------------------------------------------------------------------------------------------
                                                                                     Proposed       Proposed 7-
                                                                                  annual take by    year total
                    Species                                   Stock                   Level B      take by Level
                                                                                    harassment     B harassment
----------------------------------------------------------------------------------------------------------------
California sea lion...........................  U.S.............................          11,000          77,000
Harbor seal...................................  California......................             480           3,360
Northern elephant seal........................  California......................              40             280
----------------------------------------------------------------------------------------------------------------

Proposed Mitigation Measures

    Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the 
permissible methods of taking pursuant to the activity, and other means 
of effecting the least practicable adverse impact on the species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of the species or stocks for subsistence uses (``least 
practicable adverse impact''). NMFS does not have a regulatory 
definition for least practicable adverse impact. The 2004 NDAA amended 
the MMPA as it relates to military readiness activities and the 
incidental take authorization process such that a determination of 
``least practicable adverse impact'' shall include consideration of 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors. (1) The first factor is the 
manner in which, and the degree to which, the successful implementation 
of the measure(s) is expected to reduce impacts to marine mammal 
species or stocks, and their habitat. This analysis considers the 
nature of the potential adverse impact (likelihood, scope, and range). 
It further considers the likelihood that the measure will be effective 
if implemented (probability of accomplishing the mitigating result if 
implemented as planned), the likelihood of effective implementation 
(probability implemented as planned). (2) The second factor is the 
practicability of the measures for applicant implementation, which may 
consider such things as cost, impact on operations, and, in the case of 
a military readiness activity, specifically considers personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
military readiness activity.
    We refer the reader to the Navy's Northwest Training and Testing 
(NWTT) rule (85 FR 72312; November 12, 2020) for further explanation of 
our interpretation of least practicable

[[Page 37823]]

adverse impact, and what distinguishes it from the negligible impact 
standard.

Assessment of Mitigation Measures for the PMSR Study Area

    Section 216.104(a)(11) of NMFS' implementing regulations requires 
an applicant for incidental take authorization to include in its 
request, among other things, ``the availability and feasibility 
(economic and technological) of equipment, methods, and manner of 
conducting such activity or other means of effecting the least 
practicable adverse impact upon the affected species or stocks, their 
habitat, and [where applicable] on their availability for subsistence 
uses, paying particular attention to rookeries, mating grounds, and 
areas of similar significance.'' Thus NMFS' analysis of the sufficiency 
and appropriateness of an applicant's measures under the least 
practicable adverse impact standard will always begin with evaluation 
of the mitigation measures presented in the application.
    NMFS has fully reviewed the specified activities and the mitigation 
measures included in the Navy's rulemaking/LOA application and the 2020 
PMSR DEIS/OEIS to determine if the mitigation measures would result in 
the least practicable adverse impact on marine mammals and their 
habitat. NMFS worked with the Navy in the development of the Navy's 
initially proposed measures, which were informed by years of 
implementation and monitoring. A complete discussion of the Navy's 
evaluation process used to develop, assess, and select mitigation, 
which was informed by input from NMFS, can be found in Section 5 
(Standing Operating Procedures and Mitigation) of the 2020 PMSR DEIS/
OEIS. The process described in Section 5 (Standing Operating Procedures 
and Mitigation) of the 2020 PMSR DEIS/OEIS robustly supported NMFS' 
independent evaluation of whether the mitigation measures meet the 
least practicable adverse impact standard. The Navy would be required 
to implement the mitigation measures identified in this rule for the 
full seven years to avoid or reduce potential impacts from explosives, 
launch activities, and physical disturbance and vessel strike 
stressors.
    As a general matter, where an applicant proposes measures that are 
likely to reduce impacts to marine mammals, the fact that they are 
included in the application indicates that the measures are 
practicable, and it is not necessary for NMFS to conduct a detailed 
analysis of the measures the applicant proposed (rather, they are 
simply included). However, it is still necessary for NMFS to consider 
whether there are additional practicable measures that would 
meaningfully reduce the probability or severity of impacts that could 
affect reproductive success or survivorship.
    Overall, the Navy has agreed to procedural mitigation measures that 
would reduce the probability and/or severity of impacts expected to 
result from acute exposure to explosives and launch activities, vessel 
strike, and impacts to marine mammal habitat. Specifically, the Navy 
would use a combination of delayed starts, and cease firing to avoid 
mortality or serious injury, minimize the likelihood or severity of PTS 
or other injury, and reduce instances of TTS or more severe behavioral 
disruption caused by explosives and launch activities.
    The Navy assessed the practicability of the proposed measures in 
the context of personnel safety, practicality of implementation, and 
their impacts on the Navy's ability to meet their Title 10 requirements 
and found that the measures are supportable. As described in more 
detail below, NMFS has independently evaluated the measures the Navy 
proposed in consideration of their ability to reduce adverse impacts on 
marine mammal species and their habitat and their practicability for 
implementation. We have preliminarily determined that the measures will 
significantly and adequately reduce impacts on the affected marine 
mammal species and stocks and their habitat and, further, be 
practicable for Navy implementation. Therefore, the mitigation measures 
assure that the Navy's activities will have the least practicable 
adverse impact on the species or stocks and their habitat.
    The Navy also evaluated numerous measures in the 2020 PMSR DEIS/
OEIS that were not included in the Navy's rulemaking/LOA application, 
and NMFS independently reviewed and preliminarily concurs with the 
Navy's analysis that their inclusion was not appropriate under the 
least practicable adverse impact standard based on our assessment. The 
Navy considered these additional potential mitigation measures in two 
groups. First, Chapter 5 (Standing Operating Procedures and Mitigation) 
of the 2020 PMSR DEIS/OEIS, in the Measures Considered but Eliminated 
section, includes an analysis of an array of different types of 
mitigation that have been recommended over the years by non-
governmental organizations or the public, through scoping or public 
comment on environmental compliance documents. As described in Chapter 
5 (Standing Operating Procedures and Mitigation) of the 2020 PMSR DEIS/
OEIS, commenters sometimes recommend that the Navy reduce explosive 
use, or include area restrictions. Many of these mitigation measures 
could potentially reduce the number of marine mammals taken, via direct 
reduction of the activities or amounts. However, as described in 
Chapter 5 (Standing Operating Procedures and Mitigation) of the 2020 
PMSR DEIS/OEIS, the Navy needs to train and test in the conditions in 
which it conducts warfare, and these types of modifications 
fundamentally change the activity in a manner that would not support 
the purpose and need for the training and testing (i.e., are entirely 
impracticable) and therefore are not considered further. NMFS finds the 
Navy's explanation for why adoption of these recommendations would 
unacceptably undermine the purpose of the testing and training 
persuasive. After independent review, NMFS finds Navy's judgment on the 
impacts of potential mitigation measures to personnel safety, 
practicality of implementation, and the effectiveness of training and 
testing within the PMSR Study Area persuasive, and for these reasons, 
NMFS finds that these measures do not meet the least practicable 
adverse impact standard because they are not practicable.
    Second, in Chapter 5 (Standing Operating Procedures and Mitigation) 
of the 2020 PMSR DEIS/OEIS, the Navy evaluated an additional potential 
procedural mitigation measure, the use of thermal detection. The use of 
thermal detection had the potential to incrementally reduce take to 
some degree in certain circumstances, though the degree to which this 
would occur is typically low or uncertain. However, as described in the 
Navy's analysis, the measures would have significant direct negative 
effects on mission effectiveness and are considered impracticable (see 
Section 5 Standing Operating Procedures and Mitigation of 2020 PMSR 
DEIS/OEIS). NMFS independently reviewed the Navy's evaluation and 
concurs with this assessment, which supports NMFS' preliminary findings 
that the impracticability of this additional mitigation measure would 
greatly outweigh any potential minor reduction in marine mammal impacts 
that might result; therefore, this additional mitigation measure is not 
warranted.
    Section 5 (Standing Operating Procedures and Mitigation) of the 
2020 PMSR DEIS/OEIS also describes a comprehensive method for analyzing 
potential geographic mitigation that includes consideration of both a

[[Page 37824]]

biological assessment of how the potential time/area limitation would 
benefit the species and its habitat (e.g., is a key area of biological 
importance or would result in avoidance or reduction of impacts) in the 
context of the stressors of concern in the specific area and an 
operational assessment of the practicability of implementation (e.g., 
including an assessment of the specific importance of that area for 
training, considering proximity to training ranges and emergency 
landing fields and other issues). For most of the areas that were 
considered in the 2020 PMSR DEIS/OEIS but not included in this rule, 
the Navy found that geographic mitigation was not warranted because the 
anticipated reduction of adverse impacts on marine mammal species and 
their habitat was not sufficient to offset the impracticability of 
implementation.
    The Navy considered that moving activities farther from SNI and 
outside of the SNI Feeding Area would not be practicable, because the 
added distance would substantially limit the capabilities of ground-
based telemetry systems, antennas, surveillance, and metric radar 
systems, as well as command transmitter systems located at Point Mugu, 
Laguna Peak, Santa Cruz Island, and SNI. These systems are required to 
measure, monitor, and control various test platforms in real time; 
collect transmitted data for post event analysis; and enable 
surveillance of the area to ensure the safety of the public. Optimal 
functional distance for some of the ground-based radar systems is 10-
200 nmi and may be limited by line-of-sight for some systems. Ground-
based telemetry systems rely on using in-place fiber optic cables 
directly linked to remote locations or microwave to transmit signals. 
The ground-based command transmitter system provides safe, controlled 
testing of unmanned targets, platforms, and missiles, including 
unmanned aircraft, boat or ship targets, ballistic missiles, and other 
long-range vehicles, all within a 40-mi radius of the transmitter. The 
command transmitter system also provides flight termination capability 
for weapons and targets that are considered too hazardous for test 
flights. Relocating ground-based instrumentation to other locations 
would result in an extensive cost to the Navy, or potentially reduce 
military readiness.
    NMFS has reviewed the Navy's analysis in Section 5 Standing 
Operating Procedures and Mitigation of the 2020 PMSR DEIS/OEIS, which 
considers the same factors that NMFS considers to satisfy the least 
practicable adverse impact standard, and preliminarily concurs with the 
analysis and conclusions. Therefore, NMFS is not proposing to include 
any of the measures that the Navy ruled out in the 2020 PMSR DEIS/OEIS. 
Below are the mitigation measures that NMFS determined will ensure the 
least practicable adverse impact on all affected species and their 
habitat, including the specific considerations for military readiness 
activities. The following sections describe the mitigation measures 
that would be implemented in association with the training and testing 
activities analyzed in this document. The mitigation measures all 
consist of procedural mitigation.

Procedural Mitigation

    Procedural mitigation is mitigation that the Navy would implement 
whenever and wherever an applicable training or testing activity takes 
place within the PMSR Study Area. Procedural mitigation generally 
involves: (1) The use of one or more trained Lookouts to diligently 
observe for specific biological resources (including marine mammals) 
within a mitigation zone, (2) requirements for Lookouts to immediately 
communicate sightings of specific biological resources to the 
appropriate watch station for information dissemination, and (3) 
requirements for the watch station to implement mitigation (e.g., halt 
an activity) until certain recommencement conditions have been met. The 
first procedural mitigation (Table 20) is designed to aid Lookouts and 
other applicable Navy personnel with their observation, environmental 
compliance, and reporting responsibilities. The remainder of the 
procedural mitigation measures (Tables 21 through 29) are organized by 
stressor type and activity category and include acoustic stressors 
(i.e., weapons firing noise), explosive stressors (i.e., medium-caliber 
and large-caliber projectiles, missiles and rockets, bombs), and 
physical disturbance and strike stressors (i.e., vessel movement, 
small-, medium-, and large-caliber non-explosive practice munitions, 
non-explosive missiles, and non-explosive bombs).

     Table 20--Mitigation for Environmental Awareness and Education
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity:
     All testing and training activities, as applicable.
Mitigation Zone Size and Mitigation Requirements:
     Appropriate personnel involved in mitigation and training
     or testing activity reporting under the Proposed Action will
     complete one or more modules of the U.S Navy Afloat Environmental
     Compliance Training Series, as identified in their career path
     training plan. Modules include:
        [cir] Introduction to the U.S. Navy Afloat Environmental
         Compliance Training Series. The introductory module provides
         information on environmental laws (e.g., ESA, MMPA) and the
         corresponding responsibilities relevant to Navy testing and
         training. The material explains why environmental compliance is
         important in supporting the Navy's commitment to environmental
         stewardship.
        [cir] Marine Species Awareness Training. All bridge watch
         personnel, Commanding Officers, Executive Officers, maritime
         patrol aircraft aircrews, anti-submarine warfare and mine
         warfare rotary-wing aircrews, Lookouts, and equivalent civilian
         personnel must successfully complete the Marine Species
         Awareness Training prior to standing watch or serving as a
         Lookout. The Marine Species Awareness Training provides
         information on sighting cues, visual observation tools and
         techniques, and sighting notification procedures. Navy
         biologists developed Marine Species Awareness Training to
         improve the effectiveness of visual observations for biological
         resources, focusing on marine mammals and sea turtles, and
         including floating vegetation, jellyfish aggregations, and
         flocks of seabirds.
        [cir] U.S. Navy Protective Measures Assessment Protocol. This
         module provides the necessary instruction for accessing
         mitigation requirements during the event planning phase using
         the Protective Measures Assessment Protocol software tool.
------------------------------------------------------------------------


[[Page 37825]]

    Mitigation measures for weapons firing noise as an acoustic 
stressor is provided below in Table 21.

              Table 21--Mitigation for Weapons Firing Noise
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity Mitigation Applies to:
     Weapons firing noise associated with large-caliber gunnery
     activities.
Number of Lookouts and Observation Platform:
     1 Lookout positioned on the ship conducting the firing.
        --Depending on the activity, the Lookout could be the same as
         the one described in Table 22 (Mitigation for Small-, Medium-,
         and Large-Caliber Non-Explosive Practice Munitions).
Mitigation Requirements:
     Mitigation zone:
        --30[deg] on either side of the firing line out to 70 yd. from
         the muzzle of the weapon being fired.
     Prior to the initial start of the activity:
        --Observe the mitigation zone for floating vegetation; if
         observed, relocate or delay the start until the mitigation zone
         is clear.
        --Observe the mitigation zone for marine mammals if observed,
         relocate or delay the start of weapons firing.
     During the activity:
        --Observe the mitigation zone for floating vegetation and marine
         mammals; if observed, cease weapons firing.
     Conditions for commencing/recommencing the activity after a
     marine mammal before or during the activity:
        --The Navy will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         weapons firing) until one of the following conditions has been
         met: (1) The animal is observed exiting the mitigation zone;
         (2) the animal is thought to have exited the mitigation zone
         based on a determination of its course, speed, and movement
         relative to the firing ship; (3) the mitigation zone has been
         clear from any additional sightings for 30 min.; or (4) for
         mobile activities, the firing ship has transited a distance
         equal to double that of the mitigation zone size beyond the
         location of the last sighting and there have been no new
         sightings.
------------------------------------------------------------------------

    The Navy will implement mitigation measures to avoid or reduce 
potential impacts on marine mammals from the explosive stressors 
occurring at or near the surface resulting in underwater noise and 
energy. Mitigation measures for explosive stressors are provided in 
Table 22 through Table 24.

   Table 22--Mitigation for Explosive Medium-Caliber and Large-Caliber
                               Projectiles
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity Mitigation Applies to:
     Gunnery activities using explosive medium-caliber and large-
     caliber projectiles.
     Activities using a maritime surface target.
Number of Lookouts and Observation Platform:
     1 Lookout on the vessel or aircraft conducting the
     activity.
        --For activities using explosive large-caliber projectiles,
         depending on the activity, the Lookout could be the same as the
         one described in Table 21 (Mitigation for Weapons Firing
         Noise).
     If additional platforms are participating in the activity,
     personnel positioned in those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for
     applicable biological resources while performing their regular
     duties.
Mitigation Requirements:
     Mitigation zones:
        --200 yd (182.88 m) around the intended impact location for air-
         to-surface activities using explosive medium-caliber
         projectiles, or
        --600 yd (548.64 m) around the intended impact location for
         surface-to-surface activities using explosive medium-caliber
         projectiles, or
        --1,000 yd (914.4 m) around the intended impact location for
         surface-to-surface activities using explosive large-caliber
         projectiles.
     Prior to the start of the activity (e.g., when maneuvering
     on station):
        --Observe for floating vegetation and marine mammals; if
         observed, relocate or delay the start until the mitigation zone
         is clear.
        --During the activity, observe for floating vegetation and
         marine mammals; if resource is observed, cease firing.
     Conditions for commencing/recommencing the activity after a
     marine mammal sighting before or during the activity:
        --The Navy will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met
         until one of the recommencement conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the intended impact location; (3) the mitigation zone has been
         clear from any additional sightings for 10 min. for aircraft-
         based firing or 30 min. for vessel-based firing; or (4) for
         activities using mobile targets, the intended impact location
         has transited a distance equal to double that of the mitigation
         zone size beyond the location of the last sighting and there
         have been no new sightings .
     After completion of the activity (e.g., prior to
     maneuvering off station):
        --When practical (e.g., when platforms are not constrained by
         fuel restrictions or mission-essential follow-on commitments),
         observe the vicinity of where detonations occurred; if any
         injured or dead marine mammals, follow established incident
         reporting procedures.
If additional platforms are supporting this activity (e.g., providing
 range clearance), these assets will assist in the visual observation of
 the area where detonations occurred.
------------------------------------------------------------------------


[[Page 37826]]


         Table 23--Mitigation for Explosive Missiles and Rockets
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity Mitigation Applies to:
     Aircraft-deployed explosive missiles and rockets.
     Activities using a maritime surface target at ranges up to
     75 nmi.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in an aircraft.
     If additional platforms are participating in the activity,
     personnel positioned in those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for
     applicable biological resources while performing their regular
     duties.
Mitigation Requirements:
     Mitigation zones:
        --900 yd (822.96 m) around the intended impact location for
         missiles or rockets with 0.6-20 lb net explosive weight.
        --2,000 yd (1,828.8 m) around the intended impact location for
         missiles with 21-500 lb net explosive weight.
     Prior to the initial start of the activity (e.g., during a
     fly-over of the mitigation zone):
        --Observe the mitigation zone for floating vegetation; if
         observed, relocate or delay the start until the mitigation zone
         is clear.
        --Observe the mitigation zone for marine mammals; if observed,
         relocate or delay the start of firing.
     During the activity:
        --Observe the mitigation zone for floating vegetation and marine
         mammals; if observed, cease firing.
     Conditions for commencing/recommencing the activity after a
     marine mammal sighting before or during the activity:
        --The Navy will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the intended impact location; or (3) the mitigation zone has
         been clear from any additional sightings for 10 min. when the
         activity involves aircraft that have fuel constraints, or 30
         min. when the activity involves aircraft that are not typically
         fuel constrained.
     After completion of the activity (e.g., prior to
     maneuvering off station):
        --When practical (e.g., when platforms are not constrained by
         fuel restrictions or mission-essential follow-on commitments),
         observe the vicinity of where detonations occurred; if any
         injured or dead marine mammals or ESA-listed species are
         observed, follow established incident reporting procedures.
If additional platforms are supporting this activity (e.g., providing
 range clearance), these assets will assist in the visual observation of
 the area where detonations occurred.
------------------------------------------------------------------------


                Table 24--Mitigation for Explosive Bombs
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity Mitigation Applies to:
     Explosive bombs.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in the aircraft conducting the
     activity.
     If additional platforms are participating in the activity,
     personnel positioned in those assets (e.g., safety observers,
     evaluators) will support observing the mitigation zone for
     applicable biological resources while performing their regular
     duties.
Mitigation Requirements:
     Mitigation zone:
        --2,500 yd (2,286 m) around the intended target.
     Prior to the start of the activity (e.g., when arriving on
     station):
        --Observe the mitigation zone for floating vegetation and marine
         mammals; If floating vegetation or marine mammals are observed,
         Navy personnel must relocate or delay the start of bomb
         deployment.
     During the activity (e.g., during target approach):
        --Observe the mitigation zone for floating vegetation and marine
         mammals; if observed, cease bomb deployment.
     Conditions for commencing/recommencing of the activity
     after a marine mammal sighting before or during the activity:
        --The Navy will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         bomb deployment) until one of the recommencement conditions has
         been met: (1) The animal is observed exiting the mitigation
         zone; (2) the animal is thought to have exited the mitigation
         zone based on a determination of its course, speed, and
         movement relative to the intended target; (3) the mitigation
         zone has been clear from any additional sightings for 10 min.;
         or (4) for activities using mobile targets, the intended target
         has transited a distance equal to double that of the mitigation
         zone size beyond the location of the last sighting and there
         have been no new sightings.
     After completion of the activity (e.g., prior to
     maneuvering off station):
        --When practical (e.g., when platforms are not constrained by
         fuel restrictions or mission-essential follow-on commitments),
         observe the vicinity of where detonations occurred; if any
         injured or dead marine mammals or ESA-listed species are
         observed, follow established incident reporting procedures.
        --If additional platforms are supporting this activity (e.g.,
         providing range clearance), these assets will assist in the
         visual observation of the area where detonations occurred.
------------------------------------------------------------------------

    Mitigation for physical disturbance and strike stressors are 
provided in Table 25 through Table 29.

[[Page 37827]]



                Table 25--Mitigation for Vessel Movement
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity Mitigation Applies to:
     Vessel movement.
     The mitigation will not be required if (1) the vessel's
     safety is threatened, (2) the vessel is restricted in its ability
     to maneuver (e.g., during launching and recovery of aircraft or
     landing craft, during towing activities, when mooring, etc.), (3)
     the vessel is operated autonomously, or (4) when impracticable
     based on mission requirements (e.g., There are a few specific
     testing and training events that include requirements for certain
     systems where vessels would operate at higher speeds. As an
     example, some tests involve using the High-Speed Maneuvering
     Surface Target (HSMST). During these events, ships must operate
     across the full spectrum of capable speeds to accomplish the
     primary testing objectives).
Number of Lookouts and Observation Platform:
     1 Lookout on the vessel that is underway.
Mitigation Requirements:
     Mitigation zone:
        --500 yd (457.2 m) around whales.
        --200 yd (182.88 m) around all other marine mammals (except bow-
         riding dolphins and pinnipeds hauled out on man-made
         navigational structures, port structures, and vessels).
     During the activity:
        --When underway, observe the mitigation zone for marine mammals;
         if observed, maneuver to maintain distance.
     Additional requirements:
        --If a marine mammal vessel strike occurs, the Navy will follow
         the established incident reporting procedures.
------------------------------------------------------------------------


    Table 26--Mitigation for Small-, Medium-, and Large-Caliber Non-
                      Explosive Practice Munitions
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity Mitigation Applies to:
     Gunnery activities using small-, medium-, and large-caliber
     non-explosive practice munitions.
     Activities using a maritime surface target.
Number of Lookouts and Observation Platform:
     1 Lookout positioned on the platform conducting the
     activity.
     Depending on the activity, the Lookout could be the same as
     the one described in Table 21 (Mitigation for Weapons Firing
     Noise).
Mitigation Requirements:
     Mitigation zone:
        --200 yd (182.88 m) around the intended impact location.
     Prior to the initial start of the activity (e.g., when
     maneuvering on station):
        --Observe the mitigation zone for floating vegetation; if
         observed, relocate or delay the start until the mitigation zone
         is clear.
        --Observe the mitigation zone for marine mammals; if observed,
         relocate or delay the start of firing.
     During the activity:
        --Observe the mitigation zone for floating vegetation and marine
         mammals; if observed, cease firing.
     Conditions for commencing/recommencing the activity after a
     marine mammal sighting before or during the activity:
        --The Navy will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the intended impact location; (3) the mitigation zone has been
         clear from any additional sightings for 10 min. for aircraft-
         based firing or 30 min. for vessel-based firing; or (4) for
         activities using a mobile target, the intended impact location
         has transited a distance equal to double that of the mitigation
         zone size beyond the location of the last sighting and there
         have been no new sightings.
------------------------------------------------------------------------


       Table 27--Mitigation for Non-Explosive Missiles and Rockets
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity Mitigation Applies to:
     Aircraft-deployed non-explosive missiles and rockets.
     Activities using a maritime surface target at ranges of up
     to 75 nmi.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in an aircraft.
Mitigation Requirements:
     Mitigation zone:
        --900 yd (822.96 m) around the intended impact location.
     Prior to the initial start of the activity (e.g., during a
     fly-over of the mitigation zone):
        --Observe the mitigation zone for floating vegetation; if
         observed, relocate or delay the start until the mitigation zone
         is clear.
        --Observe the mitigation zone for marine mammals; if observed,
         relocate or delay the start of firing.
     During the activity:
        --Observe the mitigation zone for floating vegetation and marine
         mammals; if observed, cease firing.
     Conditions for commencing/recommencing the activity after a
     marine mammal sighting prior to or during the activity:

[[Page 37828]]

 
        --The Navy will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         firing) until one of the following conditions has been met: (1)
         The animal is observed exiting the mitigation zone; (2) the
         animal is thought to have exited the mitigation zone based on a
         determination of its course, speed, and movement relative to
         the intended impact location; or (3) the mitigation zone has
         been clear from any additional sightings for 10 min. when the
         activity involves aircraft that have fuel constraints, or 30
         min. when the activity involves aircraft that are not typically
         fuel constrained.
------------------------------------------------------------------------


              Table 28--Mitigation for Non-Explosive Bombs
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity Mitigation Applies to:
     Non-explosive bombs.
Number of Lookouts and Observation Platform:
     1 Lookout positioned in an aircraft.
Mitigation Requirements:
     Mitigation zone:
        --900 yd (822.96 m) around the intended impact location.
     Prior to the start of the activity (e.g., when arriving on
     station):
        --Observe the mitigation zone for floating vegetation; if
         observed, relocate or delay the start of bomb deployment until
         the mitigation zone is clear.
        --Observe the mitigation zone for marine mammals; if observed,
         relocate or delay the start of bomb deployment.
     During the activity (e.g., during approach of the target):
        --Observe the mitigation zone for floating vegetation and marine
         mammals; if observed, cease bomb deployment.
     Conditions for commencing/recommencing the activity after a
     marine mammal sighting prior to or during the activity:
        The Navy will allow a sighted marine mammal to leave the
         mitigation zone prior to the initial start of the activity (by
         delaying the start) or during the activity (by not recommencing
         bomb deployment or mine laying) until one of the following
         conditions has been met: (1) The animal is observed exiting the
         mitigation zone; (2) the animal is thought to have exited the
         mitigation zone based on a determination of its course, speed,
         and movement relative to the intended target or minefield
         location; (3) the mitigation zone has been clear from any
         additional sightings for 10 min.; or (4) for activities using
         mobile targets, the intended target has transited a distance
         equal to double that of the mitigation zone size beyond the
         location of the last sighting and there have been no new
         sightings.
------------------------------------------------------------------------

Target and Missile Launches from SNI

    Mitigation for target and missile launch activities from SNI are 
provided below in Table 29.

      Table 29--Mitigation for Target and Missile Launches From SNI
------------------------------------------------------------------------
                         Mitigation description
-------------------------------------------------------------------------
Stressor or Activity Mitigation Applies to:
     Target and Missile launches from SNI.
Mitigation Requirements:
     Navy personnel shall not enter pinniped haulouts or
     rookeries. Personnel may be adjacent to pinniped haulouts and
     rookeries prior to and following a launch for monitoring purposes.
     Missiles shall not cross over pinniped haulouts at
     elevations less than 305 m (1,000 ft) above the haulout.
     The Navy must not conduct more than 40 launch events
     annually.
     The Navy must not conduct more than 10 launch events at
     night of the 40 annual launch events.
     Launches shall be scheduled to avoid peak pinniped pupping
     periods between January and July, to the maximum extent
     practicable.
     All manned aircraft and helicopter flight paths must
     maintain a minimum distance of 305 m (1,000 ft) from recognized
     pinniped haulouts and rookeries, except in emergencies or for real-
     time security incidents.
     For unmanned aircraft systems (UAS), the following minimum
     altitudes must be maintained over pinniped haulout areas and
     rookeries: Class 0-2 UAS must maintain a minimum altitude of 300
     ft; Class 3 UAS must maintain a minimum altitude of 500 ft; Class 4
     or 5 UAS must not be flown below 1,000 ft.
     If a species for which authorization has not been granted
     is taken, or a species for which authorization has been granted but
     the authorized takes are met, the Navy must consult with NMFS to
     determine how to proceed.
     The Navy must review the launch procedure and monitoring
     methods, in cooperation with NMFS, if any incidents of injury or
     mortality of a pinniped are discovered during post-launch surveys,
     or if surveys indicate possible effects to the distribution, size,
     or productivity of the affected pinniped populations as a result of
     the specified activities. If necessary, appropriate changes must be
     made through modification to this Authorization prior to conducting
     the next launch of the same vehicle.
------------------------------------------------------------------------

    In addition, the Navy proposes to issue awareness notification 
messages seasonally to alert ships and aircraft to the possible 
presence of concentrations of large whales in the PMSR Study Area. In 
order to maintain safety of navigation and to avoid interactions with 
large whales during transit, vessels will be instructed to remain 
vigilant to the presence of certain large whale species, which, 
especially when concentrated seasonally, may become vulnerable to

[[Page 37829]]

vessel strikes. Lookouts will use the information from the awareness 
notification messages to assist their visual observations of mitigation 
zones and to aid in implementing mitigation. The Navy anticipates that 
providing Lookouts additional information about the possible presence 
of concentrations of large whales in certain locations seasonally will 
likely help the Navy further avoid interactions with these animals 
during vessel transits and when training and testing activities are 
conducted in the PMSR Study Area. The Navy would follow reporting 
requirements should a vessel strike occur. The Navy would issue 
awareness notification messages (Table 30) for the following species 
and seasons.

          Table 30--Large Whale Awareness Notification Messages
------------------------------------------------------------------------
 
-------------------------------------------------------------------------
Blue Whale Awareness Notification Message (June 1-October 31), Gray
 Whale Awareness Notification Message (November 1-March 31), and Fin
 Whale Awareness Notification Message (November 1-May 31):
     The Navy will issue a seasonal awareness notification
     message to alert ships and aircraft operating in the area to the
     possible presence of concentrations of large whales, including blue
     whales (June 1 through October 31), gray whales (November 1 through
     March 31) and fin whales (November 1 through May 31).
     To maintain safety of navigation and to avoid interactions
     with large whales during transits, the Navy will instruct vessels
     to remain vigilant to the presence of large whale species
     (including blue whales), that when concentrated seasonally, may
     become vulnerable to vessel strikes.
     Lookouts will use the information from the awareness
     notification messages to assist their visual observation of
     applicable mitigation zones during testing and training activities
     and to aid in the implementation of mitigation observation of
     applicable mitigation zones during testing and training activities
     and to aid in the implementation of mitigation.
------------------------------------------------------------------------

Mitigation Conclusions

    NMFS has carefully evaluated the Navy's proposed mitigation 
measures--many of which were developed with NMFS' input during the 
previous phases of Navy training and testing authorizations--and 
considered a broad range of other measures (i.e., the measures 
considered but eliminated in the 2020 PMSR DEIS/OEIS, which reflect 
many of the comments that have arisen via NMFS or public input in past 
years) in the context of ensuring that NMFS prescribes the means of 
effecting the least practicable adverse impact on the affected marine 
mammal species and their habitat. Our evaluation of potential measures 
included consideration of the following factors in relation to one 
another: The manner in which, and the degree to which, the successful 
implementation of the mitigation measures is expected to reduce the 
likelihood and/or magnitude of adverse impacts to marine mammal species 
and their habitat; the proven or likely efficacy of the measures; and 
the practicability of the measures for applicant implementation, 
including consideration of personnel safety, practicality of 
implementation, and impact on the effectiveness of the military 
readiness activity.
    Based on our evaluation of the Navy's proposed measures, as well as 
other measures considered by the Navy and NMFS, NMFS has preliminarily 
determined that these proposed mitigation measures are the appropriate 
means of effecting the least practicable adverse impact on the marine 
mammal species and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and 
considering specifically personnel safety, practicality of 
implementation, and impact on the effectiveness of the military 
readiness activity. Additionally, an adaptive management provision 
ensures that mitigation is regularly assessed and provides a mechanism 
to improve the mitigation, based on the factors above, through 
modification as appropriate.
    The proposed rule comment period provides the public an opportunity 
to submit recommendations, views, and/or concerns regarding the Navy's 
activities and the proposed mitigation measures. While NMFS has 
preliminarily determined that the Navy's proposed mitigation measures 
would effect the least practicable adverse impact on the affected 
species and their habitat, NMFS will consider all public comments to 
help inform our final determination. Consequently, the proposed 
mitigation measures may be refined, modified, removed, or added to 
prior to the issuance of the final rule, based on public comments 
received, and, as appropriate, analysis of additional potential 
mitigation measures.

Proposed Monitoring

    Section 101(a)(5)(A) of the MMPA states that in order to authorize 
incidental take for an activity, NMFS must set forth requirements 
pertaining to the monitoring and reporting of such taking. The MMPA 
implementing regulations at 50 CFR 216.104(a)(13) indicate that 
requests for incidental take authorizations must include the suggested 
means of accomplishing the necessary monitoring and reporting that will 
result in increased knowledge of the species and of the level of taking 
or impacts on populations of marine mammals that are expected to be 
present.
    In the PMSR, the Navy has been monitoring missile launches at SNI 
in accordance with the MMPA under IHAs or LOAs since 2001 (NMFS, 2014a, 
2019a). Associated with those authorizations, monitoring reports 
submitted to NMFS in various periodic reports have included sound 
levels measurements from the launches and have documented the behavior 
of hauled out pinnipeds before, during, and after those launches by 
direct observation and in video recordings (Burke, 2017; Holst and 
Lawson, 2002; Holst and Greene Jr., 2005, 2006; Holst and Greene Jr., 
2008; Holst and Greene Jr., 2010; Holst et al., 2011; Holst et al., 
2003; Ugoretz and Greene Jr., 2012; Ugoretz, 2014, 2015, 2016).
    In other locations where Navy testing and training activities 
occur, the Navy has also been conducting marine mammal research and 
monitoring in the Pacific Ocean for decades. A formal coordinated 
marine species monitoring program in support of the MMPA and ESA 
authorizations for the Navy Range Complexes worldwide was first 
implemented in 2009. This robust program has resulted in hundreds of 
technical reports and publications on marine mammals that have informed 
Navy and NMFS analyses in environmental planning documents, rules, and 
ESA Biological Opinions. The reports are made available to the public 
on the Navy's marine species monitoring website 
(www.navymarinespeciesmonitoring.us), and the data on the Ocean 
Biogeographic Information System Spatial Ecological Analysis of 
Megavertebrate Populations (OBIS-SEAMAP) (http://seamap.env.duke.edu/).

[[Page 37830]]

    The Navy will continue collecting monitoring data to inform our 
understanding of the occurrence of, and impacts of the Navy's 
activities on, marine mammals on SNI in the PMSR Study Area. NMFS and 
the Navy will coordinate and discuss how monitoring in the PMSR Study 
Area could contribute to the Navy's Marine Species Monitoring Program. 
Taken together, mitigation and monitoring comprise the Navy's 
integrated approach for reducing environmental impacts from the 
specified activities. The Navy's overall monitoring approach seeks to 
leverage and build on existing research efforts whenever possible.
    As agreed upon between the Navy and NMFS, the monitoring measures 
presented here, as well as the mitigation measures described above, 
focus on the protection and management of potentially affected marine 
mammals. A well-designed monitoring program can provide important 
feedback for validating assumptions made in analyses and allow for 
adaptive management of marine resources. Monitoring is required under 
the MMPA, and details of the monitoring program for the specified 
activities have been developed through coordination between NMFS and 
the Navy through the regulatory process for previous Navy at-sea 
training and testing activities.

Required Monitoring on SNI

    In consultation with NMFS, the Navy shall implement a monitoring 
plan for beaches exposed to missile launch noise with the goal of 
assessing baseline pinniped distribution/abundance and potential 
changes in pinniped use of these beaches after launch events. Marine 
mammal monitoring shall include:
     Multiple surveys (e.g., time-lapse photography) during the 
year that record the species, number of animals, general behavior, 
presence of pups, age class, gender and reactions to launch noise or 
other natural or human caused disturbances, in addition to 
environmental conditions that may include tide, wind speed, air 
temperature, and swell.
     In addition, video and acoustic monitoring of up to three 
pinniped haulout areas and rookeries must be conducted during launch 
events that include missiles or targets that have not been previously 
monitored using video and acoustic recorders for at least three launch 
events.

Integrated Comprehensive Monitoring Program (ICMP)

    The Navy's ICMP is intended to coordinate marine species monitoring 
efforts across all regions and to allocate the most appropriate level 
and type of effort for each range complex based on a set of 
standardized objectives, and in acknowledgement of regional expertise 
and resource availability. The ICMP is designed to be flexible, 
scalable, and adaptable through the adaptive management and strategic 
planning processes to periodically assess progress and reevaluate 
objectives. This process includes conducting an annual adaptive 
management review meeting, at which the Navy and NMFS jointly consider 
the prior-year goals, monitoring results, and related scientific 
advances to determine if monitoring plan modifications are warranted to 
more effectively address program goals. Although the ICMP does not 
specify actual monitoring field work or individual projects, it does 
establish a matrix of goals and objectives that have been developed in 
coordination with NMFS. As the ICMP is implemented through the 
Strategic Planning Process for Marine Species Monitoring, detailed and 
specific studies are developed which support the Navy's and NMFS' top-
level monitoring goals. In essence, the ICMP directs that monitoring 
activities relating to the effects of Navy training and testing 
activities on marine species should be designed to contribute towards 
one or more of the following top-level goals:
    [square] An increase in our understanding of the likely occurrence 
of marine mammals and/or ESA-listed marine species in the vicinity of 
the action (i.e., presence, abundance, distribution, and/or density of 
species);
    [square] An increase in our understanding of the nature, scope, or 
context of the likely exposure of marine mammals and/or ESA-listed 
species to any of the potential stressor(s) associated with the action 
(e.g., sound, explosive detonation, or military expended materials) 
through better understanding of the following: (1) The action and the 
environment in which it occurs (e.g., sound source characterization, 
propagation, and ambient noise levels); (2) the affected species (e.g., 
life history or dive patterns); (3) the likely co-occurrence of marine 
mammals and/or ESA-listed marine species with the action (in whole or 
part); and/or (4) the likely biological or behavioral context of 
exposure to the stressor for the marine mammal and/or ESA-listed marine 
species (e.g., age class of exposed animals or known pupping, calving 
or feeding areas);
    [square] An increase in our understanding of how individual marine 
mammals or ESA-listed marine species respond (behaviorally or 
physiologically) to the specific stressors associated with the action 
(in specific contexts, where possible, e.g., at what distance or 
received level);
    [square] An increase in our understanding of how anticipated 
individual responses, to individual stressors or anticipated 
combinations of stressors, may impact either: (1) The long-term fitness 
and survival of an individual or (2) the population, species, or stock 
(e.g., through effects on annual rates of recruitment or survival);
    [square] An increase in our understanding of the effectiveness of 
mitigation and monitoring measures;
    [square] A better understanding and record of the manner in which 
the Navy complies with the incidental take regulations and LOAs and the 
ESA Incidental Take Statement;
    [square] An increase in the probability of detecting marine mammals 
(through improved technology or methods), both specifically within the 
mitigation zone (thus allowing for more effective implementation of the 
mitigation), and in general, to better achieve the above goals; and
    [square] Ensuring that adverse impact of activities remains at the 
least practicable level.

Strategic Planning Process for Marine Species Monitoring

    The Navy also developed the Strategic Planning Process for Marine 
Species Monitoring, which establishes the guidelines and processes 
necessary to develop, evaluate, and fund individual projects based on 
objective scientific study questions. The process uses an underlying 
framework designed around intermediate scientific objectives and a 
conceptual framework incorporating a progression of knowledge spanning 
occurrence, exposure, response, and consequence. The Strategic Planning 
Process for Marine Species Monitoring is used to set overarching 
intermediate scientific objectives; develop individual monitoring 
project concepts; identify potential species of interest at a regional 
scale; evaluate, prioritize and select specific monitoring projects to 
fund or continue supporting for a given fiscal year; execute and manage 
selected monitoring projects; and report and evaluate progress and 
results. This process addresses relative investments to different range 
complexes based on goals across all range complexes, and monitoring 
will leverage multiple techniques for data acquisition and analysis 
whenever possible. The Strategic Planning Process for Marine Species 
Monitoring is also available online (http://www.navymarinespeciesmonitoring.us/).

[[Page 37831]]

NMFS and the Navy will coordinate and discuss how monitoring in the 
PMSR Study Area could contribute to the Navy's Marine Species 
Monitoring Program in addition to the monitoring that would be 
conducted on SNI.

Past and Current Monitoring in the PMSR Study Area

    NMFS has received multiple years' worth of annual monitoring 
reports addressing launch activities on SNI within the PMSR Study Area 
and other Navy range complexes. The data and information contained in 
these reports have been considered in developing mitigation and 
monitoring measures for the training and testing activities on SNI 
within the PMSR Study Area. The Navy's annual exercise and monitoring 
reports may be viewed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities and http://www.navymarinespeciesmonitoring.us.
    Numerous publications, dissertations, and conference presentations 
have resulted from research conducted under the Navy's marine species 
monitoring program (https://www.navymarinespeciesmonitoring.us/reading-room/publications/), resulting in a significant contribution to the 
body of marine mammal science. Publications on occurrence, 
distribution, and density have fed the modeling input, and publications 
on exposure and response have informed Navy and NMFS analyses of 
behavioral response and consideration of mitigation measures.
    Furthermore, collaboration between the monitoring program and the 
Navy's research and development (e.g., the Office of Naval Research) 
and demonstration-validation (e.g., Living Marine Resources) programs 
has been strengthened, leading to research tools and products that have 
already transitioned to the monitoring program. These include Marine 
Mammal Monitoring on Ranges (M3R), controlled exposure experiment 
behavioral response studies (CEE BRS), acoustic sea glider surveys, and 
global positioning system-enabled satellite tags. Recent progress has 
been made with better integration of monitoring across all Navy at-sea 
study areas, including study areas in the Pacific and the Atlantic 
Oceans, and various testing ranges. Publications from the Living Marine 
Resources and the Office of Naval Research programs have also resulted 
in significant contributions to information on hearing ranges and 
acoustic criteria used in effects modeling, exposure, and response, as 
well as developing tools to assess biological significance (e.g., 
population-level consequences).
    NMFS and the Navy also consider data collected during mitigations 
as monitoring. Data are collected by shipboard personnel on hours spent 
training, hours of observation, and marine mammals observed within the 
mitigation zones when mitigations are implemented. These data are 
provided to NMFS in both classified and unclassified annual exercise 
reports, which will continue under this rule.
    Research funded by the Navy that has included the PMSR Study Area 
includes, but is not limited to the following efforts:
     The Navy has funded a number of passive acoustic 
monitoring efforts in the PMSR Study Area as well as locations farther 
to the south in the SOCAL Range Complex. These studies have helped to 
characterize the soundscape resulting from general anthropogenic sound 
as well as the Navy testing and training sound energy contributions 
(Baumann-Pickering et al., 2013; Baumann-Pickering et al., 2015a; 
Baumann-Pickering et al., 2018; Curtis et al., 2020; Debich et al., 
2015a; Debich et al., 2015b; Hildebrand et al., 2012; Rice et al., 
2018a; Rice et al., 2017; Rice et al., 2018b; Sirovic et al., 2016; 
Sirovic et al., 2017; Sirovic et al., 2015b; Wiggins et al., 2018).
     Fieldwork involving photo-ID, biopsy, visual survey, and 
satellite tagging of blue, fin, and humpback whales were undertaken by 
Oregon State University. This research provided seasonal movement 
tracks, distribution, and behavior of these species in addition to 
biopsy samples used for sex determination and individual 
identifications (Mate et al., 2016; Mate et al., 2018b, 2018c; Mate et 
al., 2015b). The findings from this work have been instrumental in 
supplementing our understanding of the use of BIAs in the PMSR Study 
Area for these species.
     The Navy has been collecting abundance data and behavioral 
reactions of pinnipeds during target and missile launch on SNI since 
2001. The marine mammals monitoring reports for SNI can be found here 
https://www.navymarinespeciesmonitoring.us/reporting/pacific/.
    Additional details on the scientific objectives for the Navy's 
marine species monitoring program in the Pacific (and elsewhere) can be 
found at https://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/. Projects can be either major multi-year efforts, or 
one to two-year special studies.
    The majority of the testing and training activities Navy is 
proposing for the foreseeable future in the PMSR Study Area are similar 
if not nearly identical to activities that have been occurring in the 
same locations for decades. In the PMSR Study Area, there are no Major 
Exercises, testing and training events are, by comparison to other Navy 
areas, less frequent and are in general small in scope, so as a result 
the majority of Navy's research effort has been focused elsewhere. For 
this reason, the vast majority of scientific fieldwork, research, and 
monitoring efforts have been expended in the SOCAL Range Complex and 
Hawaii, where Navy training and testing activities have been more 
concentrated. Since 2006, the Navy has been submitting exercise reports 
and monitoring reports to NMFS for the Navy's range complexes in the 
Pacific and the Atlantic. These publicly available exercise reports, 
monitoring reports, and the associated research findings have been 
integrated into adaptive management decisions regarding the focus for 
subsequent research and monitoring as determined in collaborations 
between Navy, NMFS, Marine Mammal Commission, and other marine resource 
subject matter experts using an adaptive management approach. For 
example, see the 2019 U.S. Navy Annual Marine Species Monitoring Report 
for the Pacific that was made available to the public in September 
2020.

Adaptive Management

    The proposed regulations governing the take of marine mammals 
incidental to Navy training and testing activities in the PMSR Study 
Area contain an adaptive management component. Our understanding of the 
effects of Navy training and testing activities on marine mammals 
continues to evolve, which makes the inclusion of an adaptive 
management component both valuable and necessary within the context of 
seven-year regulations.
    The reporting requirements associated with this proposed rule are 
designed to provide NMFS with monitoring data from the previous year to 
allow NMFS to consider whether any changes to existing mitigation and 
monitoring requirements are appropriate. The use of adaptive management 
allows NMFS to consider new information from different sources to 
determine (with input from the Navy regarding practicability) on an 
annual or biennial basis if mitigation or monitoring measures should be 
modified (including additions or deletions). Mitigation or monitoring 
measures could be modified if new data suggests that such modifications 
will have a reasonable likelihood of more

[[Page 37832]]

effectively accomplishing the goals of the mitigation and monitoring 
and if the measures are practicable. If the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
will publish a notice of the proposed LOA in the Federal Register and 
solicit public comment.
    The following are some of the possible sources of applicable data 
to be considered through the adaptive management process: (1) Results 
from monitoring and exercises reports, as required by MMPA 
authorizations; (2) results from specific stranding investigations; (3) 
results from general marine mammal and sound research; and (4) any 
information which reveals that marine mammals may have been taken in a 
manner, extent, or number not authorized by these regulations or 
subsequent LOA. The results from monitoring reports and other studies 
may be viewed at https://www.navymarinespeciesmonitoring.us.

Proposed Reporting

    In order to issue incidental take authorization for an activity, 
section 101(a)(5)(A) of the MMPA states that NMFS must set forth 
requirements pertaining to the monitoring and reporting of such taking. 
Effective reporting is critical both to compliance as well as ensuring 
that the most value is obtained from the required monitoring. Reports 
from individual monitoring events, results of analyses, publications, 
and periodic progress reports for specific monitoring projects will be 
posted to the Navy's Marine Species Monitoring web portal: http://www.navymarinespeciesmonitoring.us.

Notification of Injured, Live Stranded or Dead Marine Mammals

    The Navy will consult the Notification and Reporting Plan, which 
sets out notification, reporting, and other requirements when injured, 
live stranded, or dead marine mammals are detected. The Notification 
and Reporting Plan is available at https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-testing-and-training-activities-point-mugu-sea-range.

Annual SNI Monitoring Report

    The Navy would submit an annual report to NMFS of the SNI rocket 
and missile launch activities. The draft annual monitoring report must 
be submitted to the Director, Office of Protected Resources, NMFS, 
within three months after the end of the reporting year. NMFS will 
submit comments or questions on the draft monitoring report, if any, 
within three months of receipt. The report will be considered final 
after the Navy has addressed NMFS' comments, or three months after the 
submission of the draft if NMFS does not provide comments on the draft 
report. The report would summarize the launch events conducted during 
the year; assess any direct impacts to pinnipeds from launch events; 
assess any cumulative impacts on pinnipeds from launch events; and 
summarize pinniped monitoring and research activities conducted on SNI 
and any findings related to effects of launch noise on pinniped 
populations.

Annual PMSR Training and Testing Exercise Report

    Each year the Navy will submit a detailed report (Annual PMSR 
Training and Testing Activity Report) to NMFS within three months after 
the one-year anniversary of the date of issuance of the LOA. NMFS will 
submit comments or questions on the report, if any, within one month of 
receipt. The report will be considered final after the Navy has 
addressed NMFS' comments, or one month after submission of the draft if 
NMFS does not provide comments on the draft report. The annual report 
will contain information on all explosives used, total annual number of 
each type of explosive exercises; and total annual expended/detonated 
rounds (missiles, bombs etc.) for each explosive bin. The annual report 
will also specifically include information on sound sources used. The 
annual report will also contain the current year's explosive use data 
as well as the cumulative sonar and explosive use quantity from 
previous years' reports. Additionally, if there were any changes to the 
explosives allowance in the reporting year or cumulatively, the report 
will include a discussion of why the change was made and include 
analysis to support how the change did or did not affect the analysis 
in the 2021 PMSR FEIS/OEIS and MMPA final rule. See the regulatory text 
below for detail on the content of the annual report.
    The final annual/close-out report at the conclusion of the 
authorization period (year seven) will also serve as the comprehensive 
close-out report, and will include both the final year annual use 
compared to annual authorization and a cumulative seven-year annual use 
compared to seven-year authorization. NMFS must submit comments on the 
draft close-out report, if any, within three months of receipt. The 
report will be considered final after the Navy has addressed NMFS' 
comments, or three months after the submission of the draft if NMFS 
does not provide comments.
    Information included in the annual reports may be used to inform 
future adaptive management of activities within the PMSR Study Area.

Other Reporting and Coordination

    The Navy will continue to report and coordinate with NMFS for the 
following:
     Annual marine species monitoring technical review meetings 
that also include researchers and the Marine Mammal Commission. Every 
two years a joint Pacific-Atlantic meeting is held); and
     Annual Adaptive Management meetings that also include the 
Marine Mammal Commission (recently modified to occur in conjunction 
with the annual monitoring technical review meeting).

Preliminary Analysis and Negligible Impact Determination

General Negligible Impact Analysis

Introduction
    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (i.e., population-
level effects) (50 CFR 216.103). An estimate of the number of takes 
alone is not enough information on which to base an impact 
determination. In considering how Level A harassment or Level B 
harassment factor into the negligible impact analysis, in addition to 
considering the number of estimated takes, NMFS considers other 
factors, such as the likely nature of any responses (e.g., intensity, 
duration), the context of any responses (e.g., critical reproductive 
time or location, migration), as well as effects on habitat, and the 
likely effectiveness of the mitigation. Consistent with the 1989 
preamble for NMFS' implementing regulations (54 FR 40338; September 29, 
1989), the impacts from other past and ongoing anthropogenic activities 
are incorporated into this analysis via their impacts on the baseline 
(e.g., as reflected in the regulatory status of the species, population 
size and growth rate where known).
    In the Estimated Take of Marine Mammals section of this proposed 
rule, we identified the subset of potential effects that are reasonably 
expected to occur and rise to the level of takes based on the methods 
described. The impact that any given take will have on an individual, 
and ultimately the species or stock, is dependent on many case-

[[Page 37833]]

specific factors that need to be considered in the negligible impact 
analysis (e.g., the context of behavioral exposures such as duration or 
intensity of a disturbance, the health of impacted animals, the status 
of a species that incurs fitness-level impacts to individuals, etc.). 
For this proposed rule, we evaluated the likely impacts of the number 
of harassment takes reasonably expected to occur, and proposed for 
authorization, in the context of the specific circumstances surrounding 
these predicted takes. Last, we collectively evaluated this 
information, as well as other more taxa-specific information and 
mitigation measure effectiveness, in group-specific assessments that 
support our negligible impact conclusions for each species and stock.
    As explained in the Estimated Take of Marine Mammals section, no 
take by serious injury or mortality is proposed for authorization or 
anticipated to occur.
    The Specified Activities reflect maximum levels of training and 
testing activities. The Description of the Specified Activity section 
describes annual activities. There may be some flexibility in the exact 
number of detonations that may vary from year to year, but take totals 
will not exceed the seven-year totals indicated in Table 18 as well as 
take annual and seven-year totals described for missile launch 
activities on SNI in Table 19. We base our analysis and negligible 
impact determination on the maximum number of takes that are reasonably 
expected to occur and proposed for authorization, although, as stated 
before, the number of takes are only a part of the analysis, which 
includes qualitative consideration of other contextual factors that 
influence the degree of impact of the takes on the affected 
individuals. To avoid repetition, we provide some general analysis in 
this General Negligible Impact Analysis section that applies to all the 
species and stocks listed in Tables 18 and 19, given that some of the 
anticipated effects of the Navy's training and testing activities on 
marine mammals are expected to be relatively similar in nature. Then, 
in the Group and Species-Specific Analyses section, we subdivide into 
discussions of Mysticetes, Odontocetes, and Pinnipeds as there are 
broad life history traits that support an overarching discussion of 
some factors considered within the analysis for those groups (e.g., 
high-level differences in feeding strategies). Last, we break our 
analysis into species and stock, or groups of species where relevant 
similarities exist, to provide more specific information related to the 
anticipated effects on individuals of that species or where there is 
information about the status or structure of any species that would 
lead to a differing assessment of the effects on the species. 
Organizing our analysis by grouping species that share common traits or 
that will respond similarly to effects of the Navy's activities and 
then providing species-specific information allows us to avoid 
duplication while assuring that we have analyzed the effects of the 
specified activities on each affected species and stock.
    The Navy's take request, which, as described above, is for 
harassment only, is based on its acoustic model. The model calculates 
sound energy propagation from explosives during naval activities; the 
sound or impulse received by animat dosimeters representing marine 
mammals distributed in the area around the modeled activity; and 
whether the sound or impulse energy received by a marine mammal exceeds 
the thresholds for effects. Assumptions in the Navy model intentionally 
err on the side of overestimation when there are unknowns. Naval 
activities are modeled as though they would occur regardless of 
proximity to marine mammals, meaning that no mitigation is considered 
and without any avoidance of the activity by the animal. NMFS provided 
input to, independently reviewed, and concurred with the Navy on this 
process and the Navy's analysis, which is described in detail in 
Section 6 of the Navy's rulemaking/LOA application, and which was used 
to quantify harassment takes for this proposed rule.
    Generally speaking, the Navy and NMFS anticipate more severe 
effects from takes resulting from exposure to higher received levels 
(though this is in no way a strictly linear relationship for behavioral 
effects throughout species, individuals, or circumstances), and less 
severe effects from takes resulting from exposure to lower received 
levels. However, there is also growing evidence of the importance of 
distance in predicting marine mammal behavioral response to sound--
i.e., sounds of a similar level emanating from a more distant source 
have been shown to be less likely to evoke a response of equal 
magnitude (DeRuiter 2012, Falcone et al. 2017). The estimated number of 
Level A harassment and Level B harassment takes does not equate to the 
number of individual animals the Navy expects to harass (which is 
lower), but rather to the instances of take (i.e., exposures above the 
Level A harassment and Level B harassment threshold) that are 
anticipated to occur annually and over the seven-year period. These 
instances may represent either brief exposures (seconds) or, in some 
cases, several exposures within a day. Most explosives detonating at or 
near the surface, especially those involving the larger explosive bins 
such as a MISSILEX, have brief exposures lasting only a few 
milliseconds to minutes for the entire event. Explosive events may be a 
single event involving one explosion (single exposure) or a series of 
intermittent explosives (multiple explosives) occurring over the course 
of a day. Gunnery events, in some cases, may have longer durations of 
exposure to intermittent sound. In general, gunnery events can last 
intermittently over 1-3 hrs in total; however the actual exposure 
during the event would be of a much shorter duration (seconds to 
minutes).
Behavioral Response
    Behavioral reactions from explosive sounds are likely to be similar 
to reactions studied for other impulsive sounds such as those produced 
by air guns. Impulsive signals, particularly at close range, have a 
rapid rise time and higher instantaneous peak pressure than other 
signal types, making them more likely to cause startle responses or 
avoidance responses. Most data has come from seismic surveys that occur 
over long durations (e.g., on the order of days to weeks), and 
typically utilize large multi-air gun arrays that fire repeatedly. 
While seismic air gun data provides the best available science for 
assessing behavioral responses to impulsive sounds (i.e., sounds from 
explosives) by marine mammals, it is likely that these responses 
represent a worst-case scenario compared to most Navy explosive noise 
sources. There are no explosives proposed to detonate underwater, only 
those that detonate at or near the surface of the water. For explosives 
detonating at or near the surface, an animal is considered exposed to a 
sound if the received sound level at the animal's location is above the 
background ambient noise level within a similar frequency band. For 
launches of targets and missiles from SNI, years of monitoring have 
demonstrated that sound levels at the nearest pinniped haulout site 
would produce short-term, localized changes in behavior, including 
temporarily vacating haul-outs.
    As described in the Navy's application, the Navy identified (with 
NMFS' input) the types of behaviors that would be considered a take 
(moderate behavioral responses as characterized in Southall et al. 
(2007) (e.g., altered migration paths or dive profiles, interrupted 
nursing, breeding

[[Page 37834]]

or feeding, or avoidance) that also would be expected to continue for 
the duration of an exposure). The Navy then compiled the available data 
indicating the received sound levels and distances from the sources 
when those responses have occurred to predict how many instances of 
Level B harassment by behavioral disturbance occur in a day. Take 
estimates alone do not provide information regarding the potential 
fitness or other biological consequences of the reactions on the 
affected individuals. NMFS therefore considers the available activity-
specific, environmental, and species-specific information to determine 
the likely nature of the modeled behavioral responses and the potential 
fitness consequences for affected individuals.
    In the range of potential behavioral effects that might be expected 
to be part of a response that qualifies as an instance of Level B 
harassment by behavioral disturbance (which by nature of the way it is 
modeled/counted, occurs within one day), the less severe end might 
include exposure to comparatively lower levels of a sound, at a 
detectably greater distance from the animal, for a few or several 
minutes. A less severe exposure of this nature could result in a 
behavioral response such as avoiding an area that an animal would 
otherwise have chosen to move through or feed in for some amount of 
time or breaking off one or a few feeding bouts. More severe effects 
could occur when the animal gets close enough to the source to receive 
a comparatively higher level, or is exposed intermittently to different 
sources throughout a day. Such effects might result in an animal having 
a more severe flight response and leaving a larger area for a day or 
more or potentially losing feeding opportunities for a day. However, 
such severe behavioral effects are expected to occur infrequently.
    The majority of Level B harassment takes are expected to be in the 
form of milder responses (i.e., lower-level exposures that still rise 
to the level of take) of a generally shorter duration. We anticipate 
more severe effects from takes when animals are exposed to higher 
received levels or at closer proximity to the source. However, 
depending on the context of an exposure (e.g., depth, distance, if an 
animal is engaged in important behavior such as feeding), a behavioral 
response can vary across species and individuals within a species. 
Specifically, given a range of behavioral responses that may be 
classified as Level B harassment, to the degree that higher received 
levels are expected to result in more severe behavioral responses, only 
a smaller percentage of the anticipated Level B harassment from Navy 
activities would be expected to potentially result in more severe 
responses (see the Group and Species-Specific Analyses section below 
for more detailed information). To fully understand the likely impacts 
of the predicted/authorized take on an individual (i.e., what is the 
likelihood or degree of fitness impacts), one must look closely at the 
available contextual information, such as the duration of likely 
exposures and the likely severity of the exposures (e.g., whether they 
will occur for a longer duration over sequential days or the 
comparative sound level that will be received). Ellison et al. (2012) 
and Moore and Barlow (2013), among others, emphasize the importance of 
context (e.g., behavioral state of the animals, distance from the sound 
source) in evaluating behavioral responses of marine mammals to 
acoustic sources.
Diel Cycle
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing on a diel cycle (24-hour cycle). Behavioral 
reactions to noise exposure, when taking place in a biologically 
important context, such as disruption of critical life functions, 
displacement, or avoidance of important habitat, are more likely to be 
significant if they last more than one diel cycle or recur on 
subsequent days (Southall et al., 2007). For example, Henderson et al. 
(2016) found that ongoing smaller scale events had little to no impact 
on foraging dives for Blainville's beaked whale, while multi-day 
training events may decrease foraging behavior for Blainville's beaked 
whale (Manzano-Roth et al., 2016). There are very few multi-day 
training events proposed for PMSR.
    Durations of Navy activities utilizing explosives vary and are 
fully described in Appendix A (PMSR Scenarios Descriptions) of the 2020 
PMSR DEIS/OEIS. The PMSR has activity occurring daily, but tests range 
from just a single missile launch or multiple launches, or may only be 
a captive carry where no munitions are air launched but the test is to 
determine the aircraft's ability to function properly with a missile on 
board, to a single or dual target launch from SNI, or a CSSQT where the 
ship's capability is tested by how it performs with a multiple weapons 
systems against a target. Also, while some tests are planned well in 
advance, some portions of or the entire test may be cancelled due to 
weather or atmospheric conditions, sea state, a particular system or 
support infrastructure dysfunction, or many other factors. Most 
proposed explosive detonation events are scheduled to occur over a 
short duration (one to a few hours); however, the explosive detonation 
component of the activity only lasts for seconds. Although explosive 
detonation events may sometimes be conducted in the same general areas 
repeatedly, because of their short duration and the fact that they are 
in the open ocean and animals can easily move away, it is similarly 
unlikely that animals would be exposed for long, continuous amounts of 
time, or demonstrate sustained behavioral responses. All of these 
factors make it unlikely that individuals would be exposed to the 
exercise for extended periods or on consecutive days.
Assessing the Number of Individuals Taken and the Likelihood of 
Repeated Takes
    As described previously, Navy modeling uses the best available 
science to predict the instances of exposure above certain acoustic 
thresholds, which are quantified as harassment takes. However, these 
numbers from the model do not identify whether and when the enumerated 
instances occur to the same individual marine mammal on different days, 
or how any such repeated takes may impact those individuals. One method 
that NMFS can use to help better understand the overall scope of the 
impacts is to compare the total instances of take against the abundance 
of that species (or stock if applicable). For example, if there are 100 
estimated harassment takes in a population of 100, one can assume 
either that every individual will be exposed above acoustic thresholds 
in no more than one day, or that some smaller number will be exposed in 
one day but a few individuals will be exposed multiple days within a 
year and a few not exposed at all. However, in this proposed rule the 
percentage of takes relative to abundance is under five percent for all 
species and in most cases less than one percent, meaning that it is 
less likely that individuals of most species will be taken multiple 
times, although we note that pinnipeds that haul out regularly in areas 
where activities are regularly conducted are more likely to be taken on 
multiple days.
Temporary Threshold Shift
    NMFS and the Navy have estimated that some species and stocks of 
marine mammals may sustain some level of TTS from explosive 
detonations. In general, TTS can last from a few minutes to days, be of 
varying degree, and occur across various frequency bandwidths, all of 
which determine the

[[Page 37835]]

severity of the impacts on the affected individual, which can range 
from minor to more severe. Explosives are generally referenced as 
broadband because of the various frequencies. Table 31 indicates the 
number of takes by TTS that may be incurred by different species from 
exposure to explosives. The TTS sustained by an animal is primarily 
classified by three characteristics:
    1. Frequency--Available data (of mid-frequency hearing specialists 
exposed to mid- or high-frequency sounds; Southall et al., 2007) 
suggest that most TTS occurs in the frequency range of the source up to 
one octave higher than the source (with the maximum TTS at \1/2\ octave 
above). TTS from explosives would be broadband.
    2. Degree of the shift (i.e., by how many dB the sensitivity of the 
hearing is reduced)--Generally, both the degree of TTS and the duration 
of TTS will be greater if the marine mammal is exposed to a higher 
level of energy (which would occur when the peak dB level is higher or 
the duration is longer). The threshold for the onset of TTS was 
discussed previously in this proposed rule. An animal would have to 
approach closer to the source or remain in the vicinity of the sound 
source appreciably longer to increase the received SEL. The sound 
resulting from an explosive detonation is considered an impulsive sound 
and shares important qualities (i.e., short duration and fast rise 
time) with other impulsive sounds such as those produced by air guns. 
Given the anticipated duration and levels of sound exposure, we would 
not expect marine mammals to incur more than relatively low levels of 
TTS (i.e., single digits of sensitivity loss).
    3. Duration of TTS (recovery time)--In the TTS laboratory studies 
(as discussed in the Potential Effects of Specified Activities on 
Marine Mammals and their Habitat section of the proposed rule), some 
using exposures of almost an hour in duration or up to 217 SEL, almost 
all individuals recovered within 1 day (or less, often in minutes), 
although in one study (Finneran et al., 2007) recovery took 4 days. For 
the same reasons discussed in the Preliminary Analysis and Negligible 
Impact Determination--Diel Cycle section, and because of the short 
distance animals would need to be from the sound source, it is unlikely 
that animals would be exposed to the levels necessary to induce TTS in 
subsequent time periods such that their recovery is impeded.
    The TTS takes would be the result of exposure to explosive 
detonations (broad-band). As described above, we expect the majority of 
these takes to be in the form of mild (single-digit), short-term 
(minutes to hours) TTS. This means that for one time a year, for 
several minutes, a taken individual will have slightly diminished 
hearing sensitivity (slightly more than natural variation, but nowhere 
near total deafness). The expected results of any one of these small 
number of mild TTS occurrences could be that (1) it does not overlap 
signals that are pertinent to that animal in the given time period, (2) 
it overlaps parts of signals that are important to the animal, but not 
in a manner that impairs interpretation, or (3) it reduces 
detectability of an important signal to a small degree for a short 
amount of time--in which case the animal may be aware and be able to 
compensate (but there may be slight energetic cost), or the animal may 
have some reduced opportunities (e.g., to detect prey) or reduced 
capabilities to react with maximum effectiveness (e.g., to detect a 
predator or navigate optimally). However, given the small number of 
times that any individual might incur TTS, the low degree of TTS and 
the short anticipated duration, and the low likelihood that one of 
these instances would occur across a time period in which the specific 
TTS overlapped the entirety of a critical signal, it is unlikely that 
TTS of the nature expected to result from the Navy activities would 
result in behavioral changes or other impacts that would impact any 
individual's (of any hearing sensitivity) reproduction or survival.
Auditory Masking or Communication Impairment
    The ultimate potential impacts of masking on an individual (if it 
were to occur) are similar to those discussed for TTS, but an important 
difference is that masking only occurs during the time of the signal, 
versus TTS, which continues beyond the duration of the signal. 
Fundamentally, masking is referred to as a chronic effect because one 
of the key potential harmful components of masking is its duration--the 
fact that an animal would have reduced ability to hear or interpret 
critical cues becomes much more likely to cause a problem the longer it 
is occurring. Also inherent in the concept of masking is the fact that 
the potential for the effect is only present during the times that the 
animal and the source are in close enough proximity for the effect to 
occur (and further, this time period would need to coincide with a time 
that the animal was utilizing sounds at the masked frequency). As our 
analysis has indicated, because of the sound sources primarily involved 
in this rule, we do not expect the exposures with the potential for 
masking to be of a long duration. Masking is fundamentally more of a 
concern at lower frequencies, because low frequency signals propagate 
significantly further than higher frequencies and because they are more 
likely to overlap both the narrower low-frequency calls of mysticetes, 
as well as many non-communication cues, such as sounds from fish and 
invertebrate prey and geologic sounds that inform navigation. Masking 
is also more of a concern from continuous sources (versus intermittent) 
where there is no quiet time between a sound source within which 
auditory signals can be detected and interpreted. Explosions introduce 
low-frequency, broadband sounds into the environment, which could 
momentarily mask hearing thresholds in animals that are nearby, 
although sounds from explosions last for only a few seconds at most. 
Masking due to these short duration detonations would not be 
significant. Activities that have multiple, repeated detonations, such 
as some naval gunfire activities, could result in masking for 
mysticetes near the target impact area over the duration of the event. 
Effects of masking are only present when the sound from the explosion 
is present, and the effect is over the moment the sound is no longer 
detectable. Therefore, short-term exposure to the predominantly 
intermittent explosions are not expected to result in a meaningful 
amount of masking. For the reasons described here, any limited masking 
that could potentially occur from explosives would be minor and short-
term and intermittent. Long-term consequences from physiological stress 
due to the sound of explosives would not be expected. In conclusion, 
masking is more likely to occur in the presence of broadband, 
relatively continuous noise sources such as from vessels; however, the 
duration of temporal and spatial overlap with any individual animal and 
the spatially separated sources that the Navy uses would not be 
expected to result in more than short-term, low impact masking that 
would not affect reproduction or survival of individuals.
Auditory Injury (Permanent Threshold Shift)
    Table 31 indicates the number of individuals of each species for 
which Level A harassment in the form of PTS resulting from exposure to 
or explosives is estimated to occur. The number of individuals to 
potentially incur PTS annually (from explosives) for each species 
ranges from 0 to 49 (49 is for Dall's porpoise), but is more typically 
0 or 1. As described previously, no

[[Page 37836]]

species are expected to incur non-auditory injury from explosives.
    As discussed previously, the Navy utilizes aerial monitoring in 
addition to Lookouts on vessels to detect marine mammals for mitigation 
implementation. These Level A harassment take numbers represent the 
maximum number of instances in which marine mammals would be reasonably 
expected to incur PTS, and we have analyzed them accordingly. In 
relation to TTS, the likely consequences to the health of an individual 
that incurs PTS can range from mild to more serious depending upon the 
degree of PTS and the frequency band it is in. Any PTS accrued as a 
result of exposure to Navy activities would be expected to be of a 
small amount. Permanent loss of some degree of hearing is a normal 
occurrence for older animals, and many animals are able to compensate 
for the shift, both in old age or at younger ages as the result of 
stressor exposure (Green et al., 1987; Houser et al., 2008; Ketten 
2012; Mann et al., 2010; McGfown et al., 2020). While a small loss of 
hearing sensitivity may include some degree of energetic costs for 
compensating or may mean some small loss of opportunities or detection 
capabilities, at the expected scale it would be unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
would interfere with reproductive success or survival of any 
individuals.
Physiological Stress Response
    Some of the lower level physiological stress responses (e.g., 
orientation or startle response, change in respiration, change in heart 
rate) discussed in the Potential Effects of Specified Activities on 
Marine Mammals and their Habitat would likely co-occur with the 
predicted harassments, although these responses are more difficult to 
detect and fewer data exist relating these responses to specific 
received levels of sound. However, we would not expect the Navy's 
generally short-term and intermittent activities to create conditions 
of long-term, continuous noise leading to long-term physiological 
stress responses in marine mammals that could affect reproduction or 
survival.

Group and Species-Specific Analyses

    In this section, we build on the general analysis that applies to 
all marine mammals in the PMSR Study Area from the previous section, 
and include first information and analysis that applies to mysticetes 
or, separately, odontocetes, and pinnipeds and then within those three 
sections, more specific information that applies to smaller groups, 
where applicable, and the affected species and stocks. The specific 
take numbers proposed for authorization are discussed in Tables 31 and 
32, and here we provide some additional context and discussion 
regarding how we consider the proposed take numbers in those analyses. 
The maximum amount and type of incidental take of marine mammals 
reasonably likely to occur from explosive detonations and target and 
missile launch activities and therefore authorized during the seven-
year training and testing period are shown in Tables 31 and 32 below. 
The vast majority of predicted exposures are expected to be Level B 
harassment (TTS and behavioral disturbance) from explosive sources 
during training and testing activities and missile launch activities on 
SNI.

 Table 31-- Annual Estimated Takes by Level A and Level B Harassment for Marine Mammals in the PMSR Study Area (Excluding SNI) and the Number Indicating
                                             the Instances of Total Take as a Percentage of Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Proposed annual take by Level A and Level B
                                                                            harassment                                       Abundance
            Common name                   Stock/DPS      ------------------------------------------------   Total take      (2020 draft    Percent taken
                                                            Behavioral                                                         SARS)       by abundance
                                                             response           TTS             PTS
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale *......................  Eastern North                      7               4               0              11           1,496            0.74
                                     Pacific.
Fin whale *.......................  California, Oregon,               14               7               1              22           9,029            0.24
                                     and Washington.
Gray whale........................  Eastern North                      9               5               0              14          26,960            0.05
                                     Pacific.
Humpback whale *..................  California, Oregon,                7               4               0              11           2,900            0.38
                                     and Washington/
                                     Mexico DPS.
                                    California, Oregon,                1               0               0               1           2,900            0.03
                                     and Washington/
                                     Central America DPS.
Minke whale.......................  California, Oregon,                2               1               0               3             636            0.47
                                     and Washington.
Bottlenose dolphin................  California, Oregon,                5               5               1              11            1924            0.57
                                     and Washington
                                     Offshore.
Dall's porpoise...................  California, Oregon,              261             406              49             716          25,750            2.78
                                     and Washington.
Dwarf sperm whale.................  California, Oregon,               20              31               6              57           4,111            1.39
                                     and Washington.
Long-beaked common dolphin........  California..........              66              44               9             119         101,305            0.12
Northern right whale dolphin......  California, Oregon,                3               2               1               6          26,556            0.02
                                     and Washington.
Pacific white-sided dolphin.......  California, Oregon,               11               8               2              21          26,814            0.08
                                     and Washington.
Pygmy sperm whale.................  California, Oregon,               20              31               6              57           4,111            1.39
                                     and Washington.

[[Page 37837]]

 
Risso's dolphins..................  California, Oregon,                6               3               1              10           6,336            0.16
                                     and Washington.
Short-beaked common dolphin.......  California, Oregon,               90              65              15             170         969,861            0.02
                                     and Washington.
Sperm whale *.....................  California, Oregon,                1               1               0               2           1,997            0.10
                                     and Washington.
Striped dolphin...................  California, Oregon,                1               1               0               2          29,211            0.01
                                     and Washington.
Harbor seal.......................  California..........             202             120              14             336          30,968            1.08
Northern elephant seal............  California..........              37              63              22             122         179,000            0.07
California sea lion...............  U.S. Stock..........               8              12               2              22         257,606            0.01
Guadalupe fur seal *..............  Mexico to California               1               1               0               2          34,187            0.01
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Percentages taken by abundance may be less for some stocks as the abundance would be less in the PMSR Study Area depending on the range of a
  particular stock.
* ESA-listed species in PMSR Study Area.


Table 32--Annual Estimated Takes by Level A and Level B Harassment for Pinniped on SNI and the Number Indicating
                         the Instances of Total Take as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
                                                     Proposed                                       Proposed 7-
                                                  annual take by     Abundance     Percent taken    year total
             Species                   Stock          Level B       (2020 draft    by abundance    take by Level
                                                    harassment         SARS)                       B harassment
----------------------------------------------------------------------------------------------------------------
California sea lion.............            U.S.          11,000         257,606            4.27          77,000
Harbor seal.....................      California             480          30,968            1.55           3,360
Northern elephant seal..........      California              40         179,000            0.02             280
----------------------------------------------------------------------------------------------------------------

    In the discussions below, the estimated takes by Level B harassment 
represent instances of take, not the number of individuals taken (the 
much lower and less frequent takes by Level A harassment are far more 
likely to be associated with separate individuals). The total take 
numbers (by any method of taking) for species are compared to their 
associated abundance estimates to evaluate the magnitude of impacts 
across the species and to individuals. Abundance percentage comparisons 
are less than three percent for all species and stocks and nearly all 
are one percent or less and zero in many cases for explosives and less 
than five percent for all species on SNI from target and missile launch 
activities. This means that: (1) Not all of the individuals will be 
taken, and many will not be taken at all; (2) barring specific 
circumstances suggesting repeated takes of individuals (such as in 
circumstances where all activities resulting in take are focused in one 
area and time where the same individual marine mammals are known to 
congregate, such as pinnipeds on SNI), the average or expected number 
of days taken for those individuals taken is one per year; and (3) we 
would not expect any individuals to be taken more than a few times in a 
year, or for those days to be sequential.
    To assist in understanding what this analysis means, we clarify a 
few issues related to estimated takes and the analysis here. An 
individual that incurs PTS or TTS may sometimes, for example, also be 
subject to direct behavioral disturbance at the same time. As described 
above in this section, the degree of PTS, and the degree and duration 
of TTS, expected to be incurred from the Navy's activities are not 
expected to impact marine mammals such that their reproduction or 
survival could be affected. Similarly, data do not suggest that a 
single instance in which an animal incurs PTS or TTS and also has an 
additional direct behavioral response would result in impacts to 
reproduction or survival. Accordingly, in analyzing the numbers of 
takes and the likelihood of repeated and sequential takes, we consider 
all the types of take, so that individuals potentially experiencing 
both threshold shift and direct behavioral responses are appropriately 
considered. The number of Level A harassment takes by PTS are so low 
(and zero in most cases) compared to abundance numbers that it is 
considered highly unlikely that any individual would be taken at those 
levels more than once.
    On the less severe end, exposure to comparatively lower levels of 
sound at a detectably greater distance from the animal, for a few or 
several minutes, could result in a behavioral response such as avoiding 
an area that an animal would otherwise have moved through or fed in, or 
breaking off one or a few feeding bouts. More severe behavioral effects 
could occur when an animal gets close enough to the source to receive a 
comparatively higher level of sound, is exposed continuously to one 
source for a longer time, or is exposed intermittently to different 
sources throughout a day. Such effects might result in an animal having 
a more severe flight response and leaving a larger area for a day or 
more, or potentially losing feeding opportunities for a day. However, 
such severe behavioral effects are not expected to occur.
    Occasional, milder behavioral reactions are unlikely to cause long-
term

[[Page 37838]]

consequences for individual animals or populations, and even if some 
smaller subset of the takes are in the form of a longer (several hours 
or a day) and more severe responses, if they are not expected to be 
repeated over sequential days, impacts to individual fitness are not 
anticipated. Nearly all studies and experts agree that infrequent 
exposures of a single day or less are unlikely to impact an 
individual's overall energy budget (Farmer et al., 2018; Harris et al., 
2017; King et al., 2015; NAS 2017; New et al., 2014; Southall et al., 
2007; Villegas-Amtmann et al., 2015).
    The analyses below in some cases address species and stocks 
collectively if they occupy the same functional hearing group (i.e., 
low, mid, and high-frequency cetaceans and pinnipeds), share similar 
life history strategies, and/or are known to behaviorally respond 
similarly to stressors. Because some of these groups or species share 
characteristics that inform the impact analysis similarly, it would be 
duplicative to repeat the same analysis for each species. In addition, 
similar species typically have the same hearing capabilities and 
behaviorally respond in the same manner.
    Thus, our analysis below considers the effects of the Navy's 
activities on each affected species even where discussion is organized 
by functional hearing group and/or information is evaluated at the 
group level. Where there are meaningful differences between species 
that would further differentiate the analysis, they are either 
described within the section or the discussion for those species is 
included as a separate subsection. Specifically, below we first give 
broad descriptions of the mysticete, odontocete, and pinniped groups 
and then differentiate into further groups and species as appropriate.
Mysticetes
    This section builds on the broader discussion above and brings 
together the discussion of the different types and amounts of take that 
different species are likely to incur, the applicable mitigation, and 
the status of the species to support the negligible impact 
determinations for each species. We have described (above in the 
General Negligible Impact Analysis section) the unlikelihood of any 
masking having effects that would impact the reproduction or survival 
of any of the individual marine mammals affected by the Navy's 
activities. We also described in the Potential Effects of Specified 
Activities on Marine Mammals and their Habitat section of the proposed 
rule the unlikelihood of any habitat impacts having effects that would 
impact the reproduction or survival of any of the individual marine 
mammals affected by the Navy's activities. There is no predicted non-
auditory tissue damage from explosives for any species, and only one 
take by PTS of any mysticete (fin whale) annually. Much of the 
discussion below focuses on the behavioral effects and the mitigation 
measures that reduce the probability or severity of effects. Because 
there are species-specific considerations, at the end of the section we 
break out our findings on a species-specific basis.
    In Table 31 above, we indicate for each species the total annual 
numbers of take by Level A and Level B harassment for mysticetes, and a 
number indicating the instances of total take as a percentage of 
abundance in the PMSR Study Area. Note also that for mysticetes, the 
abundance within the PMSR Study Area represents only a portion of the 
species or stock abundance.
    No Bryde's whales, gray whales (Western North Pacific stock), or 
sei whales would be taken by Level A harassment or Level B harassment 
and therefore are not discussed further. For other mysticetes, exposure 
to explosives will result in small numbers of take: 1-14 Takes by Level 
B harassment by behavioral disturbance per species, and 4-7 by TTS per 
species. One take by PTS will result for fin whales and 0 for all other 
mysticetes. Based on this information, the majority of the Level B 
harassment by behavioral disturbance is expected to be of low severity 
and of shorter duration. No non-auditory tissue damage from training 
and testing activities is anticipated or authorized for any species.
    Research and observations show that if mysticetes are exposed to 
impulsive sounds such as those from explosives, they may react in a 
variety of ways, which may include alerting, startling, breaking off 
feeding dives and surfacing, diving or swimming away, changing 
vocalization, or showing no response at all (DOD, 2017; Nowacek, 2007; 
Richardson, 1995; Southall et al., 2007). Overall and in consideration 
of the context for an exposure, mysticetes have been observed to be 
more reactive to acoustic disturbance when a noise source is located 
directly in their path or the source is nearby (somewhat independent of 
the sound level) (Dunlop et al., 2016; Dunlop et al., 2018; Ellison et 
al., 2011; Friedlaender et al., 2016; Henderson et al., 2019; Malme et 
al., 1985; Richardson et al., 1995; Southall et al., 2007a). Mysticetes 
have been observed to be more reactive to acoustic disturbance when a 
noise source is located directly on their migration route. Mysticetes 
disturbed while migrating could pause their migration or route around 
the disturbance, while males en route to breeding grounds have been 
shown to be less responsive to disturbances. Although some may pause 
temporarily, they will resume migration shortly after the exposure 
ends. Animals disturbed while engaged in other activities such as 
feeding or reproductive behaviors may be more likely to ignore or 
tolerate the disturbance and continue their natural behavior patterns. 
Because noise from most activities using explosives is short term and 
intermittent, and because detonations usually occur within a small 
area, behavioral reactions from mysticetes, if they occur at all, are 
likely to be short term and of little to no significance.
    Noise from explosions is broadband with most energy below a few 
hundred Hz; therefore, any reduction in hearing sensitivity from 
exposure to explosive sounds is likely to be broadband with effects 
predominantly at lower frequencies. Mysticetes that do experience 
threshold shift (i.e., TTS or the one instance of PTS for fin whale) 
from exposure to explosives may have reduced ability to detect 
biologically important sounds (e.g., social vocalizations). For 
example, during the short period that a mysticete experiences TTS, 
social calls from conspecifics could be more difficult to detect or 
interpret, the ability to detect predators may be reduced, and the 
ability to detect and avoid sounds from approaching vessels or other 
stressors might be reduced. Any TTS that would occur would be of short 
duration.
    While NMFS can make a negligible impact determination on Navy's 
estimated take numbers, the implementation of mitigation and the 
sightability of mysticetes (especially given their large size) reduces 
the potential for, and severity of, any threshold shift for mysticetes. 
When we look in ocean areas where the Navy has been intensively 
training and testing with explosive and other active acoustic sources 
for decades, there are no data suggesting any long-term consequences to 
reproduction or survival rates of mysticetes from explosives and other 
active acoustic sources. All the mysticete species discussed in this 
section will benefit from the mitigation measures described earlier in 
the Proposed Mitigation Measures section. Below we compile and 
summarize the information that supports our determination that the 
Navy's activities will not adversely affect any species through effects 
on annual rates of

[[Page 37839]]

recruitment or survival for any of the affected mysticete species.
    Humpback whale--As noted in the Description of Marine Mammals and 
Their Habitat in the Area of the Specified Activities section, humpback 
whales in the PMSR Study Area are part of the ESA-threatened Mexico DPS 
and ESA-endangered Central America DPS of the CA/OR/WA stock with an 
increasing population trend. ESA Critical Habitat has been proposed in 
the PMSR Study Area. There are two biologically important areas for 
humpback whale feeding that overlap with a portion of the PMSR Study 
Area--the Morro Bay to Point Sal Feeding Area (designated from April to 
November) and the Santa Barbara Channel-San Miguel Feeding Area 
(designated from March to September) (Calambokidis et al., 2015). Navy 
testing and training activities that use explosives could occur year 
round within the PMSR Study Area, although they generally would not 
occur in these relatively nearshore feeding areas, because both areas 
are close to the northern Channel Islands NMS, oil production 
platforms, and major vessel routes leading to and from the ports of Los 
Angeles and Long Beach. Further, even if some small number of humpback 
whale takes occurred in these BIAs and were to disrupt feeding 
behaviors, the short-term nature of the anticipated takes from these 
activities, combined with the likelihood that they would not occur on 
more than one day for any individual within a year, means that they are 
not expected to impact the reproduction or survival of any individuals.
    NMFS proposes 12 takes by Level B harassment would occur (see Table 
31): 7 takes by behavioral disturbance and 4 takes by TTS for Mexico 
DPS humpback whales and 1 take by behavioral disturbance and 0 takes by 
TTS for Central America DPS humpback whales (Table 31). Regarding the 
magnitude of takes by Level B harassment (TTS and behavioral 
disruption), the number of estimated total instances of take compared 
to the abundance is less than 1 percent (Table 31). Regarding the 
severity of those individual takes by Level B harassment by behavioral 
disturbance, we have explained that the duration of any exposure is 
expected to be between seconds and minutes (i.e., short duration) 
(i.e., of a low level and unlikely to evoke a severe response). 
Regarding the severity of takes by TTS, they are expected to be low-
level, of short duration not at a level that will impact reproduction 
or survival.
    Altogether, the CA/OR/WA stock includes the ESA-listed Mexico DPS 
(threatened) and Central America (endangered) DPS of humpback whales 
and has an increasing population trend. There is proposed critical 
habitat for humpback whales in the PMSR Study Area. Our analysis 
suggests only a very small portion of the stock will be taken and 
disturbed at a low-level with those individuals disturbed on likely one 
day within a year. The proposed takes are not expected to result in 
impacts on the reproduction or survival of any individuals, let alone 
have impacts on annual rates of recruitment or survival. No Level A 
harassment, serious injury, or mortality is anticipated or proposed for 
authorization. This low magnitude and severity of harassment effects is 
not expected to result in impacts on the reproduction or survival of 
any individuals, let alone have impacts on annual rates of recruitment 
or survival. Therefore, the total take will not adversely affect this 
species through impacts on annual rates of recruitment or survival. For 
these reasons, we have preliminarily determined, in consideration of 
all of the effects of the Navy's activities combined, that the proposed 
take will have a negligible impact on humpback whales.
    Blue whale--Blue whales are listed as endangered under the ESA 
throughout their range. The Eastern North Pacific stock occurs in the 
PMSR Study Area with a stable population trend (NMFS 2019; Calambokidis 
and Barlow, 2020). There is no ESA-designated critical habitat, but 
there are three biologically important areas (BIAs) for feeding 
identified for blue whales in the PMSR Study Area. The feeding areas 
overlap (one wholly and two partially) with the PMSR Study Area (June 
through October). Navy testing and training activities that use 
explosives could occur year round within the PMSR Study Area. However, 
activities using explosives generally would not take place in the Point 
Conception/Arguello to Point Sal Feeding Area or the Santa Barbara 
Channel and San Miguel Feeding Area, because both areas are close to 
the northern Channel Islands NMS, oil production platforms, and major 
vessel routes leading to and from the ports of Los Angeles and Long 
Beach. The SNI feeding area overlaps a part of the PMSR Study Area that 
has been in high use for Navy testing and training activities for 
decades. Over the years, there has been very little change in Navy 
testing and training off SNI, and the waters within Warning Area 289, 
which overlap with the SNI Feeding Area, are essential for testing and 
training given their proximity to SNI. The area is used during 
activities requiring an aerial target impact area, missile launches 
from SNI, aerial and ship-based gunnery events, and sea surface missile 
launches. Even if some small number of blue whale takes occurred in 
these BIAs and were to disrupt feeding behaviors, the short-term nature 
of the anticipated takes from these activities, combined with the 
likelihood that they would not occur on more than one day for any 
individual within a year, means that they are not expected to impact 
the reproduction or survival of any individuals.
    NMFS proposes to authorize 11 takes by Level B harassment, 7 takes 
by behavioral disturbance and 4 takes by TTS for blue whales (Table 
31). Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance is less than 1 percent (Table 31). Regarding 
the severity of those individual takes by Level B harassment by 
behavioral disturbance, we have explained that the duration of any 
exposure is expected to be between seconds and minutes (i.e., short 
duration) (i.e., of a low- level). Regarding the severity of takes by 
TTS, they are expected to be low-level, of short duration not at a 
level that will impact reproduction or survival.
    Altogether, blue whales are listed as endangered, though the 
Eastern North Pacific stock is stable, and has a very large range. Our 
analysis suggests that a very small portion of the stock will be taken 
and disturbed at a low-level, with those individuals disturbed on 
likely one day within a year. No Level A harassment, serious injury, or 
mortality is anticipated or proposed for authorization. This low 
magnitude and severity of harassment effects is not expected to result 
in impacts on the reproduction or survival of any individuals, let 
alone have impacts on annual rates of recruitment or survival. 
Therefore, the total take will not adversely affect this species 
through impacts on annual rates of recruitment or survival. For these 
reasons, we have preliminarily determined, in consideration of all of 
the effects of the Navy's activities combined, that the proposed take 
will have a negligible impact on blue whales.
    Fin whale--Fin whales are listed as endangered under the ESA 
throughout their range, with no ESA designated critical habitat or 
known biologically important areas identified for this species in the 
PMSR Study Area. The population trend for the CA/OR/WA stock, found in 
the PMSR Study Area, is increasing (NMFS 2019).

[[Page 37840]]

    NMFS proposes to authorize 22 takes by Level B harassment, 14 takes 
by behavioral disturbance, 7 takes by TTS, and 1 take by PTS for fin 
whales (Table 31). Regarding the magnitude of takes by Level B 
harassment (TTS and behavioral disruption), the number of estimated 
total instances of take compared to the abundance is less than 1 
percent (Table 31). Regarding the severity of those individual takes by 
Level B harassment by behavioral disturbance, we have explained that 
the duration of any exposure is expected to be between seconds and 
minutes (i.e., short) (i.e., of a low level). Regarding the severity of 
takes by TTS, they are expected to be low-level, of short duration not 
at a level that will impact reproduction or survival.
    Altogether, fin whales are listed as endangered, with no designated 
critical habitat or biologically important areas in the PMSR Study 
Area, and the CA/OR/WA stock is increasing. Our analysis suggests that 
a very small portion of the stock will be taken and disturbed at a low 
level, with those individuals disturbed on likely one day within a 
year. No serious injury or mortality is anticipated or proposed for 
authorization. This low magnitude and severity of harassment effects is 
not expected to result in impacts on the reproduction or survival of 
any individuals, let alone have impacts on annual rates of recruitment 
or survival. Therefore, the total take will not adversely affect this 
species through impacts on annual rates of recruitment or survival. For 
these reasons, we have preliminarily determined, in consideration of 
all of the effects of the Navy's activities combined, that the proposed 
take will have a negligible impact on fin whales.
    Gray whale (Eastern North Pacific stock)--The Gray whale (Eastern 
North Pacific stock) is not listed as endangered or threatened under 
the ESA and has an increasing population trend. There is an active UME 
for gray whales off the West Coast. The Eastern North Pacific 
population of gray whales that migrate along the West Coast has 
declined about 24 percent since 2016. It now stands at an estimated 
20,580 whales (Stellar and Weller 2021). That is similar to previous 
fluctuations in the Eastern North Pacific population that has since 
recovered from the days of whaling. The decline coincides with the UME 
declared in 2019 and resembles a similar 23 percent decline documented 
after a UME 20 years earlier, in 1999-2000. The gray whale population 
rebounded following that previous UME to greater numbers than before. 
The continuing change in gray whale numbers suggests that large-scale 
fluctuations of this nature are not rare. The observed declines in 
abundance appear to represent short-term events that have not resulted 
in any detectable longer-term impacts on the population. We do not 
anticipate any mortality or impacts on reproduction or survival of any 
individuals, and given the low magnitude and severity of effects from 
Level B harassment only, even with the UME, they will not result in 
impacts on individual reproduction or survival, much less annual rates 
of recruitment or survival. Therefore, population-level effects to gray 
whales from the Navy's activities despite the UME are not anticipated.
    Four designated biologically important areas for migration for gray 
whales (Calambokidis et al., 2015) overlap with the PMSR Study Area and 
are active migration areas from October through July, although each 
individual area has its own specific date range depending on what 
portion of the northbound or southbound migration it is meant to cover. 
Gray whales would cross the PMSR Study Area twice a year during their 
annual southbound and northbound migrations. Navy testing and training 
activities that use explosives could occur year round within the PMSR 
Study Area, but generally they would occur farther offshore than the 
shallow-water, nearshore habitat generally preferred by gray whales 
during their migration. In an early study investigating the behavior of 
migrating gray whales exposed to an impulsive source in their migration 
path, a startle response was observed in 42 percent of the cases, but 
the change in behavior, when it occurred, did not persist (Malme et 
al., 1984; Malme et al., 1988; Richardson, 1995). If a gray whale were 
to react to sound from an explosion, it may pause its migration until 
the noise ceases or moves, or it may choose an alternate route around 
the location of the sound source if the source was directly in the 
whale's migratory path. Even if some small number of gray whale takes 
occurred in these BIAs in the form of disrupted feeding behaviors or 
traveling for migration, the short-term nature of the anticipated takes 
from these activities, combined with the likelihood that they would not 
occur on more than one day for any individual within a year, mean that 
they are not expected to impact the reproduction or survival of any 
individuals.
    NMFS proposes to authorize 14 takes by Level B harassment, 9 takes 
by behavioral disturbance and 5 takes by TTS for gray whales (Table 
31). Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance is less than 1 percent (Table 31). Regarding 
the severity of those individual takes by Level B harassment by 
behavioral disturbance, we have explained that the duration of any 
exposure is expected to be between minutes and hours (i.e., relatively 
short) (i.e., of a moderate or lower level, less likely to evoke a 
severe response). Regarding the severity of takes by TTS, they are 
expected to be low-level, of short duration not at a level that will 
impact reproduction or survival.
    Altogether, gray whales (Eastern North Pacific stock) are not 
listed under the ESA and the population is increasing. Our analysis 
suggests that a very small portion of the stock will be taken and 
disturbed at a low level, with those individuals disturbed on likely 
one day within a year. No Level A harassment, serious injury, or 
mortality is anticipated or proposed for authorization. This low 
magnitude and severity of harassment effects is not expected to result 
in impacts on the reproduction or survival of any individuals, either 
alone or in combination with the effects of the UME, let alone have 
impacts on annual rates of recruitment or survival. Therefore, the 
total take will not adversely affect this species through impacts on 
annual rates of recruitment or survival. For these reasons, we have 
preliminarily determined, in consideration of all of the effects of the 
Navy's activities combined, that the proposed take will have a 
negligible impact on gray whales.
    Minke whale--Minke whale is not listed as endangered or threatened 
under the ESA and there are no known biologically important areas 
identified for these species in the PMSR Study Area. The CA/OR/WA stock 
occurs in the PMSR Study Area with no known population trend.
    NMFS proposes to authorize 3 takes by Level B harassment, 2 takes 
by behavioral disturbance and 1 take by TTS for minke whales (Table 
31). Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance is less than 1 percent (Table 31). Regarding 
the severity of those individual takes by Level B harassment by 
behavioral disturbance, we have explained that the duration of any 
exposure is expected to be between minutes and hours (i.e., relatively 
short) (i.e., of a moderate or lower level, less likely to evoke a 
severe response). Regarding the severity of takes by TTS,

[[Page 37841]]

they are expected to be low-level, of short duration not at a level 
that will impact reproduction or survival.
    Altogether, minke whales are not listed under the ESA and with no 
known population trend. Our analysis suggests that a very small portion 
of the stock will be taken and disturbed at a low level, with those 
individuals disturbed likely one day within a year. No Level A 
harassment, serious injury, or mortality is anticipated or proposed for 
authorization. This low magnitude and severity of harassment effects is 
not expected to result in impacts on the reproduction or survival of 
any individuals, let alone have impacts on annual rates of recruitment 
or survival. Therefore, the total take will not adversely affect this 
species through impacts on annual rates of recruitment or survival. For 
these reasons, we have preliminarily determined, in consideration of 
all of the effects of the Navy's activities combined, that the proposed 
take will have a negligible impact on minke whales.
Odontocetes
    This section builds on the broader discussion above and brings 
together the discussion of the different types and amounts of take that 
different species are likely to incur, the applicable mitigation for 
each species, and the status of the species to support the negligible 
impact determinations for each species. We have described (above in the 
General Negligible Impact Analysis section) the unlikelihood of any 
masking having effects that would impact the reproduction or survival 
of any of the individual marine mammals affected by the Navy's 
activities. We also described in the Potential Effects of Specified 
Activities on Marine Mammals and their Habitat section of this proposed 
rule the unlikelihood of any habitat impacts having effects that would 
impact the reproduction or survival of any of the individual marine 
mammals affected by the Navy's activities. There is no predicted PTS 
from explosives for most odontocetes, with the exception of a few 
species, which is discussed below. There is no predicted non-auditory 
tissue damage from explosives for any species. Much of the discussion 
below focuses on the behavioral effects and the mitigation measures 
that reduce the probability or severity of effects. Here, we include 
information that applies to all of the odontocete species, which are 
then further divided and discussed in more detail in the following 
subsections: Kogia whales; sperm whales; beaked whales; porpoise, and 
dolphins and small whales. These subsections include more specific 
information about the groups, as well as conclusions for each species 
represented.
    In Table 31 above, we indicate for each species the total annual 
numbers of take by Level A and Level B harassment for odontocetes, and 
a number indicating the instances of total take as a percentage of 
abundance in the PMSR Study Area. Note also that, for all odontocetes 
where estimated take is requested, their abundance within the PMSR 
Study Area represents only a portion of their respective species 
population.
    No Baird's beaked whale, Cuvier's beaked whale, Mesoplodont spp. 
harbor porpoise, bottlenose dolphin (California coastal stock), killer 
whale, or short-finned pilot whale will be taken by Level A harassment 
or Level B harassment and therefore are not discussed further.
    Odontocete echolocation occurs predominantly at frequencies 
significantly higher than 20 kHz, though there may be some small 
overlap at the lower part of their echolocating range for some species, 
which means that there is little likelihood that threshold shift, 
either temporary or permanent would interfere with feeding behaviors. 
Many of the other critical sounds that serve as cues for navigation and 
prey (e.g., waves, fish, invertebrates) occur below a few kHz and the 
threshold shift that might be incurred by individuals exposed to 
explosives would likely be lower frequency (5 kHz or less) and spanning 
a wider frequency range, which could slightly lower an individual's 
sensitivity to navigational or prey cues, or a small portion of 
communication calls, for several minutes to hours (if temporary) or 
permanently. There is no reason to think that any of the individual 
odontocetes taken by TTS would incur these types of takes over more 
than one day, and therefore they are unlikely to result in impacts on 
reproduction or survival. The number of PTS takes from these activities 
are very low (0 annually for most, 1-15 for a few species, and 49 for 
Dall's porpoise), and as discussed previously because of the low degree 
of PTS (i.e., low amount of hearing sensitivity loss), it is unlikely 
to affect reproduction or survival of any individuals.
    The range of potential behavioral effects of sound exposure on 
marine mammals generally, and odontocetes specifically, has been 
discussed in detail previously. There are behavioral patterns that 
differentiate the likely impacts on odontocetes as compared to 
mysticetes. First, odontocetes echolocate to find prey, which means 
that they actively send out sounds to detect their prey. While there 
are many strategies for hunting, one common pattern, especially for 
deeper diving species, is many repeated deep dives within a bout, and 
multiple bouts within a day, to find and catch prey. As discussed 
above, studies demonstrate that odontocetes may cease their foraging 
dives in response to sound exposure. If enough foraging interruptions 
occur over multiple sequential days, and the individual either does not 
take in the necessary food, or must exert significant effort to find 
necessary food elsewhere, energy budget deficits can occur that could 
potentially result in impacts to reproductive success, such as 
increased cow/calf intervals (the time between successive calving). 
Second, while many mysticetes rely on seasonal migratory patterns that 
position them in a geographic location at a specific time of the year 
to take advantage of ephemeral large abundances of prey (i.e., 
invertebrates or small fish, which they eat by the thousands), 
odontocetes forage more homogeneously on one fish or squid at a time. 
Therefore, if odontocetes are interrupted while feeding, it is often 
possible to find more prey relatively nearby.
    Dwarf Sperm Whales and Pygmy Sperm Whales (Kogia species)--This 
section builds on the broader odontocete discussion above and brings 
together the discussion of the different types and amounts of take that 
these two species are likely to incur, the applicable mitigation, and 
the status of the species to support the negligible impact 
determinations for each species. Some Level A harassment by PTS is 
anticipated annually (6 takes for Dwarf and pygmy whale, see Table 31).
    In Table 31 above, we indicate for each species the total annual 
numbers of take by Level A and Level B harassment above for dwarf sperm 
whales and pygmy sperm whales, and a number indicating the instances of 
total take as a percentage of the abundance within the PMSR Study Area. 
Note also that, for dwarf and pygmy sperm whales (and all odontocetes), 
the abundance within the PMSR Study Area represents only a portion of 
the species abundance.
    As discussed above, the majority of takes by Level B harassment by 
behavioral disturbance of odontocetes, and thereby dwarf and pygmy 
sperm whales, is expected to be in the form of low severity of a 
shorter duration. As discussed earlier in this section, we anticipate 
more severe effects from takes when animals are exposed to higher 
received levels or for longer durations. Occasional milder Level B 
harassment

[[Page 37842]]

by behavioral disturbance, as is expected here, is unlikely to cause 
long-term consequences for either individual animals or populations.
    We note that dwarf and pygmy sperm whales, as HF-sensitive species, 
have a lower PTS threshold than all other groups and therefore are 
generally likely to experience larger amounts of TTS and PTS. NMFS 
accordingly has evaluated slightly higher numbers of take for these 
species than most odontocetes (some of which would have zero takes of 
TTS/PTS). Even though the number of TTS and PTS takes are higher than 
for other odontocetes, any TTS and PTS is expected to be at a low to 
moderate level and for all of the reasons described above, TTS and PTS 
takes are not expected to impact reproduction or survival of any 
individual.
    Neither pygmy sperm whales nor dwarf sperm whales are listed under 
the ESA, and there are no known biologically important areas identified 
for these species in the PMSR Study Area. The CA/OR/WA stocks specified 
for pygmy sperm whales and dwarf sperm whales are found in the PMSR 
Study Area. There is no information on trends for these species within 
the PMSR Study Area. Both pygmy and dwarf sperm whales will benefit 
from the mitigation measures described earlier in the Proposed 
Mitigation Measures section.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance is less than 2 percent for both dwarf and 
pygmy sperm whales in the PMSR Study Area (Table 31). Regarding the 
severity of those individual Level B harassment takes by behavioral 
disruption, we have explained that the duration of any exposure is 
expected to be between seconds and minutes (i.e., short duration). 
Regarding the severity of TTS takes, they are expected to be low to 
moderate level, of short duration, and are broadband that would be 
expected to interfere with dwarf or pygmy sperm whale communication or 
other important cues. Therefore, the associated lost opportunities and 
capabilities are not at a level that will impact reproduction or 
survival. Dwarf sperm whales and pygmy sperm whales could be taken by a 
small amount of PTS annually, of likely low to moderate severity as 
described previously. A small permanent loss of hearing sensitivity 
(PTS) may include some degree of energetic costs for compensating or 
may mean some small loss of opportunities or detection capabilities, 
but at the expected degree the estimated takes by Level A harassment 
takes by PTS for dwarf sperm whales and pygmy sperm whales are unlikely 
to impact behaviors, opportunities, or detection capabilities to a 
degree that will interfere with reproductive success or survival of any 
individuals, let alone affect annual rates of recruitment or survival 
for the species.
    Altogether, dwarf and pygmy sperm whales are not listed under the 
ESA and there are no known population trends. Our analysis suggests 
that a small portion of the stock in the PMSR Study Area will be taken, 
and disturbed at a low to moderate level, with those individuals likely 
not disturbed on more than one day a year. No serious injury or 
mortality is anticipated or proposed for authorization. The low 
magnitude and low to moderate severity of harassment effects is not 
expected to result in impacts on the reproduction or survival of any 
individuals, let alone have impacts on annual rates of recruitment or 
survival. Therefore, the total take will not adversely affect this 
species through impacts on annual rates of recruitment or survival. 
Some individuals are estimated to be taken by PTS of likely low to 
moderate severity. A small permanent loss of hearing sensitivity (PTS) 
may include some degree of energetic costs for compensating or may mean 
some small loss of opportunities or detection capabilities, but at the 
expected scale the estimated takes by Level A harassment by PTS are 
unlikely to impact behaviors, opportunities, or detection capabilities 
to a degree that would interfere with reproductive success or survival 
of any individuals, let alone affect annual rates of recruitment or 
survival. For these reasons, we have preliminarily determined, in 
consideration of all of the effects of the Navy's activities combined, 
that the proposed take will have a negligible impact on both dwarf and 
pygmy sperm whales.
    Sperm whale--This section brings together the broader discussion 
above with the discussion of the different types and amounts of take 
that sperm whales could potentially incur, the applicable mitigation, 
and the status of the species to support the negligible impact 
determination.
    In Table 31 above, we indicate the total annual numbers of take by 
Level A and Level B harassment for sperm whales, and a number 
indicating the instances of total take as a percentage of the abundance 
within the PMSR Study Area. Note also that, for sperm whales, the 
abundance within the PMSR Study represents only a portion of the 
species abundance.
    As discussed above, the majority of take by Level B harassment by 
behavioral disturbance of odontocetes, and thereby sperm whales, is 
expected to be in the form of low severity of a generally shorter 
duration and is unlikely to cause long-term consequences for either 
individual animals or populations.
    Sperm whales are listed as endangered under the ESA throughout 
their range, but there is no ESA designated critical habitat or known 
biologically important areas identified for this species within the 
PMSR Study Area. The CA/OR/WA stock occurs in the PMSR Study with a 
stable population trend (NMFS 2019). Sperm whales will benefit from the 
mitigation measures described earlier in the Proposed Mitigation 
Measures section.
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance is less than 1 percent in the PMSR Study Area 
(Table 31). Regarding the severity of those individual takes by Level B 
harassment by behavioral disturbance, we have explained that the 
duration of any exposure is expected to be between seconds and minutes 
(i.e., short duration) and of a low level. Regarding the severity of 
TTS takes, they are expected to be low-level, of short duration, and 
mostly not in a frequency band that would be expected to interfere with 
important low-frequency cues, and would not be at a level that will 
impact reproduction or survival.
    Altogether, sperm whales are listed as endangered under the ESA and 
have a stable population trend. Our analysis suggests that very few 
individuals within the PMSR Study Area will be taken and disturbed at a 
low level, with those individuals disturbed on likely one day within a 
year. No Level A harassment, serious injury, or mortality is 
anticipated or proposed for authorization. This low magnitude and 
severity of harassment effects is not expected to result in impacts on 
the reproduction or survival of any individuals, let alone have impacts 
on annual rates of recruitment or survival. Therefore, the total take 
will not adversely affect this species through impacts on annual rates 
of recruitment or survival. For these reasons, we have preliminarily 
determined, in consideration of all of the effects of the Navy's 
activities combined, that the proposed take will have a negligible 
impact on sperm whales.

[[Page 37843]]

    Porpoise (Dall's Porpoise)--This section builds on the broader 
odontocete discussion above and brings together the discussion of the 
different types and amounts of take that Dall's porpoise are likely to 
incur, the applicable mitigation, and the status of the species to 
support the negligible impact determinations for each species. Some 
Level A harassment by PTS is anticipated annually (49 takes, see Table 
31).
    In Table 31 above, we indicate the total annual numbers of take by 
Level A and Level B harassment for Dall's porpoise, and a number 
indicating the instances of total take as a percentage of the abundance 
within the PMSR Study Area. Note also that, for Dall's porpoise (and 
all odontocetes), the abundance within the PMSR Study Area represents 
only a portion of the species abundance.
    As discussed above, the majority of takes by Level B harassment by 
behavioral disturbance of odontocetes, and thereby Dall's porpoise, is 
expected to be in the form of low to moderate severity of a shorter 
duration. As discussed earlier in this section, we anticipate more 
severe effects from takes when animals are exposed to higher received 
levels or for longer durations. Occasional milder Level B harassment by 
behavioral disturbance, as is expected here, is unlikely to cause long-
term consequences for either individual animals or populations.
    We note that Dall's porpoise, as HF-sensitive species, have a lower 
PTS threshold than all other groups and therefore are generally likely 
to experience larger amounts of TTS and PTS. NMFS accordingly has 
evaluated slightly higher numbers of take for these species than most 
odontocetes (some of which would have zero takes of TTS/PTS). 
Therefore, even though the number of TTS and PTS takes are higher than 
for other odontocetes, any TTS or PTS is expected to be at a low to 
moderate level and for all of the reasons described above, TTS and PTS 
takes are not expected to impact reproduction or survival of any 
individual.
    Dall's porpoise are not listed under the ESA, and there are no 
known biologically important areas identified for these species in the 
PMSR Study Area. The CA/OR/WA stock is found in the PMSR Study Area. 
There is no information on trends for this species within the PMSR 
Study Area. Dall's porpoise will benefit from the mitigation measures 
described earlier in the Proposed Mitigation Measures section.
    Regarding the magnitude of Level B harassment takes (TTS and 
behavioral disruption), the number of estimated total instances of take 
compared to the abundance is less than 3 percent for Dall' porpoise in 
the PMSR Study Area (Table 31). Regarding the severity of those 
individual Level B harassment takes by behavioral disruption, we have 
explained that the duration of any exposure is expected to be between 
seconds and minutes (i.e., relatively short duration). Regarding the 
severity of TTS takes, they are expected to be low to moderate level, 
of short duration, and mostly not in a frequency band that would be 
expected to interfere with communication and, therefore, the associated 
lost opportunities and capabilities are not at a level that will impact 
reproduction or survival. Dall's porpoise could be taken by a small 
amount of PTS annually, of likely low to moderate severity as described 
previously. A small permanent loss of hearing sensitivity (PTS) may 
include some degree of energetic costs for compensating or may mean 
some small loss of opportunities or detection capabilities, but at the 
expected degree the estimated takes by Level A harassment takes by PTS 
for Dall's porpoise are unlikely to impact behaviors, opportunities, or 
detection capabilities to a degree that will interfere with 
reproductive success or survival of any individuals, let alone affect 
annual rates of recruitment or survival.
    Altogether, Dall's porpoise are not listed under the ESA and there 
are no known population trends for the CA/OR/WA stock. Our analysis 
suggests that a small portion of the stock will be taken, and disturbed 
at a low to moderate level, with those individuals likely not disturbed 
on more than one day or so a year. No serious injury or mortality is 
anticipated or proposed for authorization. The low magnitude and low to 
moderate severity of harassment effects is not expected to result in 
impacts on the reproduction or survival of any individuals, let alone 
have impacts on annual rates of recruitment or survival. Therefore, the 
total take will not adversely affect this species through impacts on 
annual rates of recruitment or survival. Some individuals are estimated 
to be taken by PTS of likely low to moderate severity. A small 
permanent loss of hearing sensitivity (PTS) may include some degree of 
energetic costs for compensating or may mean some small loss of 
opportunities or detection capabilities, but at the expected scale the 
estimated takes by Level A harassment by PTS are unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
would interfere with reproductive success or survival of any 
individuals, let alone affect annual rates of recruitment or survival. 
For these reasons, we have preliminarily determined, in consideration 
of all of the effects of the Navy's activities combined, that the 
proposed take will have a negligible impact on Dall's porpoise.
    Small Whales and Dolphins--This section builds on the broader 
discussion above and brings together the discussion of the different 
types and amounts of take that different small whale and dolphin 
species are likely to incur, the applicable mitigation, and the status 
of the species to support the negligible impact determinations for each 
species.
    In Table 31 above, we indicate for each species the total annual 
numbers of take by Level A and Level B harassment for dolphins and 
small whales, and a number indicating the instances of total take as a 
percentage of abundance in the PMSR Study Area. Note also that, for 
dolphins and small whales, the abundance within the PMSR Study Area 
represents only a portion of the respective species abundance.
    The majority of takes by Level B harassment are expected to be in 
the form of low severity of a shorter duration. Occasional milder Level 
B harassment by behavioral disturbance, as is expected here, is 
unlikely to cause long-term consequences for either individual animals 
or populations that have any effect on reproduction or survival. 
Limited Level A harassment (PTS) is anticipated and proposed for six 
species (Long and short-beaked common dolphins, bottlenose dolphin, 
Risso's dolphin, Pacific white-sided dolphin, and Northern right whale 
dolphin).
    Research and observations show that if delphinids are exposed to 
sounds they may react in a number of ways depending on their experience 
with the sound source and what activity they are engaged in at the time 
of the acoustic exposure. Delphinids may not react at all until the 
sound source is approaching within a few hundred meters, such as with a 
ship with hull-mounted sonar, to within a few kilometers, depending on 
the environmental conditions and species. Some dolphin species (the 
more surface-dwelling taxa--typically those with ``dolphin'' in the 
common name, such as bottlenose dolphins, spotted dolphins, spinner 
dolphins, rough-toothed dolphins, etc., but not Risso's dolphins), 
especially those residing in more industrialized or busy areas, have 
demonstrated more tolerance for disturbance and loud sounds and many of 
these species are known to approach

[[Page 37844]]

vessels to bow-ride. These species are often considered generally less 
sensitive to disturbance. Dolphins and small whales that reside in 
deeper waters and generally have fewer interactions with human 
activities are more likely to demonstrate more typical avoidance 
reactions and foraging interruptions as described above in the 
odontocete overview.
    All the dolphin and small whale species discussed in this section 
will benefit from the mitigation measures described earlier in the 
Proposed Mitigation Measures section.
    None of the small whale and dolphin species are listed as 
endangered or threatened species under the ESA. There are CA/OR/WA 
stocks for most of the small whales and dolphins found in the PMSR 
Study Area and most have unknown population trends, with the exception 
of the Short-beaked common dolphin that has a stable population trend 
and the Long-beaked common dolphin (California stock) that has an 
increasing population trend.
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disturbance), the number of estimated total instances of 
take compared to the abundance is less than one percent for the 
dolphins and small whales in the PMSR Study Area (Table 31). Regarding 
the severity of those individual takes by Level B harassment by 
behavioral disturbance, we have explained the duration of any exposure 
is expected to be between seconds and minutes (i.e., short duration). 
Regarding the severity of takes by TTS, they are expected to be low-
level, of short duration and not at a level that will impact 
reproduction or survival. One to two individuals each of four species 
(Bottlenose dolphin, Northern right whale dolphin, Pacific white-
dolphin, Risso's dolphin) are estimated to be taken by one to two PTS 
annually, of likely low severity as described previously. Slightly more 
takes by PTS for short-beaked common dolphin and long-beaked common 
dolphin are proposed for authorization, 15 and 9 takes, respectively. A 
small permanent loss of hearing sensitivity may include some degree of 
energetic costs for compensating or may mean some small loss of 
opportunities or detection capabilities, but at the expected scale the 
estimated takes by Level A harassment by PTS are unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
will interfere with reproductive success or survival of any 
individuals, let alone affect annual rates of recruitment or survival.
    Altogether, none of the small whale or dolphin species are listed 
under the ESA and there are no known population trends for most 
species. No serious injury or mortality is anticipated or proposed for 
authorization. Our analysis suggests that only a small portion of the 
individuals of any of these species in the PMSR Study Area will be 
taken and disturbed at a low level, with those individuals likely 
disturbed no more than a day a year. Some take by PTS for five dolphin 
species is anticipated and proposed for authorization, but at the 
expected scale the estimated take by Level A harassment by PTS is 
unlikely to impact behaviors, opportunities, or detection capabilities 
to a degree that would interfere with reproductive success or survival 
of any individuals, let alone annual rates of recruitment or survival. 
This low magnitude and severity of harassment effects is not expected 
to result in impacts on the reproduction or survival of any 
individuals, let alone have impacts on annual rates of recruitment or 
survival. Therefore, the total take will not adversely affect these 
species through impacts on annual rates of recruitment or survival. For 
these reasons, we have preliminarily determined, in consideration of 
all of the effects of the Navy's activities combined, that the 
authorized take will have a negligible impact on all of these species 
of small whales and dolphins.

Pinnipeds

    This section builds on the broader discussion above and brings 
together the discussion of the different types and amounts of take that 
different species and stocks of pinnipeds will likely incur, the 
applicable mitigation, and the status of the species and stocks to 
support the negligible impact determinations for each species or stock. 
We have described (above in the General Negligible Impact Analysis 
section) the unlikelihood of any masking having effects that will 
impact the reproduction or survival of any of the individual marine 
mammals affected by the Navy's activities. We have also described in 
the Potential Effects of Specified Activities on Marine Mammals and 
their Habitat section of this proposed rule that the specified 
activities would not have adverse or long-term impacts on marine mammal 
habitat, and therefore the unlikelihood of any habitat impacts 
affecting the reproduction or survival of any individual marine mammals 
affected by the Navy's activities. For pinnipeds, no serious injury or 
mortality is anticipated or proposed for authorization. Here, we 
include information that applies to all of the pinniped species and 
stocks.
    In Table 31 and 32 above, we indicate the total annual numbers of 
take by Level A and Level B harassment for pinnipeds, and a number 
indicating the instances of total take as a percentage of the abundance 
within the PMSR Study Area by explosives and also by missile and rocket 
launch activities on SNI. Note also that, for pinniped species and 
stocks, the abundance within the PMSR Study Area represents only a 
portion of the species abundance.
    The majority of take by Level B harassment by behavioral 
disturbance of pinnipeds, is expected to be in the form of low severity 
of short duration for explosives and low to moderate severity of short 
duration for target and missile launches on SNI and is unlikely to 
cause long-term consequences for either individual animals or 
populations.
    Pinnipeds in the PMSR Study Area are not listed under the ESA with 
the exception of the threatened Guadalupe fur seal (Mexico stock), but 
there is no ESA designated critical habitat for the Guadalupe fur seal. 
Pupping does occur on SNI beaches, January through July. The Guadalupe 
fur seal has an increasing population trend. Nevertheless, there is an 
active UME for Guadalupe fur seal. Since 2015, there have been 492 
strandings of Guadalupe fur seals (including live and dead seals). 
However, we do not anticipate any mortality or impacts on reproduction 
or survival of any individuals, and, given the low magnitude and 
severity of effects from Level B harassment only (2 Level B harassment 
takes annually), even with the UME they will not result in impacts on 
individual reproduction or survival, much less annual rates of 
recruitment or survival. Therefore, population-level effects to 
Guadalupe fur seal from the Navy's activities despite the UME are not 
anticipated. The California sea lion UME was recently closed, as 
elevated strandings occurred from 2013-2016. The U.S. stock of 
California sea lions has an increasing population trend. The California 
stocks of Northern Elephant seal and Northern fur seals also have an 
increasing population trend. The California stock of harbor seals has a 
stable population trend. Pinnipeds will benefit from the mitigation 
measures described earlier in the Proposed Mitigation Measures section.
    Regarding the magnitude of takes by Level B harassment (TTS and 
behavioral disruption) for explosives, the number of estimated total 
instances of take compared to the abundance is approximately 1 percent 
or less in the PMSR Study Area (Table 31). Regarding the magnitude of 
takes by Level B harassment (TTS and behavioral

[[Page 37845]]

disruption) for target and missile launches, the number of estimated 
total instances of take compared to the abundance is less than five 
percent in the PMSR Study Area (Table 32). Given this information and 
the ranges of these stocks (i.e., large ranges, but with individuals 
often staying in the vicinity of haulouts), only a small portion of 
individuals in these stocks are likely impacted and repeated exposures 
of individuals are not anticipated during explosives (i.e., individuals 
are not expected to be taken on more than a few days within a year). 
Regarding the severity of those individual takes by Level B harassment 
by behavioral disturbance for explosives, the duration of any exposure 
is expected to be between seconds and minutes (i.e., short duration). 
Regarding the severity of TTS takes from explosives, they are expected 
to be of low-level and short duration, and any associated lost 
opportunities and capabilities would not be at a level that will impact 
reproduction or survival.
    Three species of pinnipeds (harbor seals, Northern elephant seal, 
and California sea lions) are estimated to be taken by PTS from 
explosives, 14, 22, and 2 takes, respectively, of likely low severity. 
A small permanent loss of hearing sensitivity (PTS) may include some 
degree of energetic costs for compensating or may mean some small loss 
of opportunities or detection capabilities, but at the expected scale 
the estimated takes by Level A harassment by PTS are unlikely to impact 
behaviors, opportunities, or detection capabilities to a degree that 
will interfere with reproductive success or survival of any 
individuals, let alone affect annual rates of recruitment or survival.
    For missile launch activities on SNI, the proposed activities may 
result in take, in the form of Level B harassment only, from airborne 
sounds of missile launch activities (Table 32). A portion of 
individuals in these stocks are likely impacted and repeated exposures 
of individuals are anticipated during missile and target launches for 
pinnipeds hauled out on SNI (i.e., individuals are expected to be taken 
on up to several days within a year), however, there is no reason to 
expect that these disturbances would occur on sequential days.
    Regarding the magnitude of takes by Level B harassment, the number 
of estimated total instances of take compared to the abundance is less 
than 5 percent on SNI for all pinniped species (Table 32). Based on the 
best available information, including monitoring reports from similar 
activities that have been authorized by NMFS, Level B harassment will 
likely be limited behavioral reactions such as alerting to the noise, 
with some animals possibly moving toward or entering the water (i.e., 
movements of more than 10 m and occasional flushing into the water with 
return to haulouts), depending on the species and the intensity of the 
launch noise. Regarding the severity of those individual takes by Level 
B harassment, any exposure is expected to be low to moderate and of 
relatively short duration and are unlikely to result in hearing 
impairment or to significantly disrupt foraging behavior. Given the 
launch acceleration and flight speed of the missiles, most launch 
events are of extremely short duration. Strong launch sounds are 
typically detectable near the beaches at western SNI for no more than a 
few seconds per launch (Holst et al., 2010; Holst et al., 2005a; Holst 
et al., 2008; Holst et al., 2005b). Pinnipeds hauled out on beaches 
where missiles fly over launched from the Alpha Launch Complex 
routinely haul out and continue to use these beaches in large numbers, 
but at the Building 807 Launch Complex few pinnipeds are known to haul 
out on the shoreline immediately adjacent to this launch site. We do 
not expect repeated exposures to occur on sequential days as it can 
take up to several weeks of planning between launch events. Responses 
of pinnipeds on beaches during launches are highly variable. Harbor 
seals can be more reactive when hauled out compared to other species, 
such as northern elephant seals. Northern elephant seals generally 
exhibit no reaction at all, except perhaps a heads-up response or some 
stirring. However, stronger reactions may occur if California sea lions 
are in the same area mingled with the northern elephant seals and the 
sea lions react strongly. While the reactions are variable, and can 
involve abrupt movements by some individuals, biological impacts of 
these responses appear to be limited. Even some number of repeated 
instances of Level B harassment (with no particular likelihood of 
sequential days or more sustained effect) of some small subset of an 
overall stock is unlikely to result in any decrease in fitness to those 
individuals, and thus would not result in any adverse impact to a stock 
as a whole. Flushing of pinnipeds into the water has the potential to 
result in mother-pup separation, or a stampede, either of which could 
potentially result in serious injury or mortality. For example, in some 
cases, harbor seals at SNI appear to be more responsive during the 
pupping/breeding season (Holst et al. 2005a; Holst et al. 2008), while 
in others, mothers and pups seem to react less to launches than lone 
individuals (Ugoretz and Greene Jr. 2012), and California sea lions 
seem to be consistently less responsive during the pupping season 
(Holst et al. 2010; Holst et al. 2005a; Holst et al. 2008; Holst et al. 
2011; Holst et al. 2005b; Ugoretz and Greene Jr. 2012). Though pup 
abandonment could theoretically result from these reactions, site-
specific monitoring data indicate that pup abandonment is not likely to 
occur as a result of the target and missile launches, as it has not 
been previously observed. As part of mitigation the Navy would avoid 
target and missile launches during the peak pinniped pupping season to 
the maximum extent practicable, and missiles would not cross over 
pinniped haulouts at elevations less than 305 m (1,000 ft). Based on 
the best available information, including reports from almost 20 years 
of marine mammal monitoring during launch events, no injury, serious 
injury, or mortality of marine mammals has occurred from any flushing 
events or is anticipated or proposed for authorization.
    Altogether, pinnipeds are not listed under the ESA (except for 
Guadalupe fur seal that are threatened) and all pinniped stocks have 
increasing, stable, or unknown population trends. Our analysis suggests 
that a small portion of the stocks will be taken and disturbed at a 
low-moderate level, with those individuals disturbed on likely one day 
within a year from explosives and some individuals on SNI likely 
disturbed a few days a year within a year from target and missile 
launches. No serious injury or mortality is anticipated or proposed for 
authorization. No more than 22 individuals from three pinniped stocks 
are estimated to be taken by PTS, of likely low severity, annually. 
Additionally, no PTS is expected for Guadalupe fur seal. This low to 
moderate magnitude and severity of harassment effects is not expected 
to result in impacts on the reproduction or survival of any individuals 
(either alone or in combination with the effects of the UME for 
Guadulupe fur seal), let alone have impacts on annual rates of 
recruitment or survival, and therefore the total take will not 
adversely affect this species through impacts on annual rates of 
recruitment or survival. For these reasons, we have preliminarily 
determined, in consideration of all of the effects of the Navy's 
activities combined, that the proposed take will have a negligible 
impact on pinnipeds.

[[Page 37846]]

Determination

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

Subsistence Harvest of Marine Mammals

    In order to issue an incidental take authorization, NMFS must find 
that the specified activity will not have an ``unmitigable adverse 
impact'' on the subsistence uses of the affected marine mammal species 
or stocks by Alaskan Natives. NMFS has defined ``unmitigable adverse 
impact'' in 50 CFR 216.103 as an impact resulting from the specified 
activity: (1) That is likely to reduce the availability of the species 
to a level insufficient for a harvest to meet subsistence needs by: (i) 
Causing the marine mammals to abandon or avoid hunting areas; (ii) 
Directly displacing subsistence users; or (iii) Placing physical 
barriers between the marine mammals and the subsistence hunters; and 
(2) That cannot be sufficiently mitigated by other measures to increase 
the availability of marine mammals to allow subsistence needs to be 
met.
    To our knowledge there are no relevant subsistence uses of the 
affected marine mammal stocks or species implicated by this action. 
Therefore, NMFS has preliminarily determined that the total taking of 
affected species or stocks would not have an unmitigable adverse impact 
on the availability of the species or stocks for taking for subsistence 
purposes.

Classification

Endangered Species Act

    There are six marine mammal species under NMFS jurisdiction that 
are listed as endangered or threatened under the ESA with confirmed or 
possible occurrence in the PMSR Study Area: Blue whale, fin whale, gray 
whale, humpback whale, sei whale, and sperm whale. NMFS published a 
proposed rule on ESA-designated critical habitat for humpback whales 
(84 FR 54354; October 9, 2019).
    The Navy will consult with NMFS pursuant to section 7 of the ESA 
for PMSR Study Area activities. NMFS will also consult internally on 
the issuance of the regulations and LOA under section 101(a)(5)(A) of 
the MMPA.

National Marine Sanctuaries Act

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

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 proposed actions and alternatives with respect 
to potential impacts on the human environment. Accordingly, NMFS plans 
to adopt the PMSR FEIS/OEIS for the PMSR Study Area, 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 2020 PMSR DEIS/OEIS and has worked extensively with the Navy in 
developing the document. The 2020 PMSR DEIS/OEIS was made available for 
public comment (85 FR 55257, April 24, 2020) (Also see https://pmsr-eis.com). We will review all comments submitted in response to the 
request for comments on the 2020 PMSR DEIS/OEIS 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 Navy to incidentally take marine 
mammals during the specified activities.

Executive Order 12866

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

Regulatory Flexibility Act

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

List of Subjects in 50 CFR Part 218

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

    Dated: July 1, 2021.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.

    For the reasons set out in the preamble, 50 CFR part 648 is 
proposed to be amended as follows:

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

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

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

0
2. Revise subpart B to read as follows:
Subpart B--Taking and Importing Marine Mammals; U.S. Navy's Point Mugu 
Sea Range (PMSR) Training and Testing (PMSR) Study Area
Sec.
218.10 Specified activity and geographical region.
218.11 Effective dates.
218.12 Permissible methods of taking.
218.13 Prohibitions.
218.14 Mitigation requirements.
218.15 Requirements for monitoring and reporting.
218.16 Letters of Authorization.
218.17 Renewals and modifications of Letters of Authorization.
218.18 Reserved
218.19 Reserved

[[Page 37847]]

Subpart B--Taking and Importing Marine Mammals; U.S. Navy's Point 
Mugu Sea Range (PMSR) Training and Testing (PMSR) Study Area


Sec.  218.10  Specified activity and geographical region.

    (a) Regulations in this subpart apply only to the U.S. Navy for the 
taking of marine mammals that occurs in the area described in paragraph 
(b) of this section and that occurs incidental to the activities listed 
in paragraph (c) of this section.
    (b) The taking of marine mammals by the Navy under this subpart may 
be authorized in a Letter of Authorization (LOA) only if it occurs 
within the Point Mugu Sea Range (PMSR) Training and Testing Study Area. 
The PMSR Study Area is located adjacent to Los Angeles, Ventura, Santa 
Barbara, and San Luis Obispo Counties along the Pacific Coast of 
Southern California and includes a 36,000-square-mile sea range. The 
two primary components of the PMSR Complex are Special Use Airspace and 
the ocean Operating Areas.
    (c) The taking of marine mammals by the Navy is only authorized if 
it occurs incidental to the Navy conducting training and testing 
activities, including:
    (1) Training.
    (i) Air warfare;
    (ii) Electronic warfare; and
    (iii) Surface warfare.
    (2) Testing.
    (i) Air warfare;
    (ii) Electronic warfare; and
    (iii) Surface warfare.


Sec.  218.11  Effective dates.

    Regulations in this subpart are effective from October 31, 2021, 
through October 30, 2028.


Sec.  218.12  Permissible methods of taking.

    (a) Under an LOA issued pursuant to Sec. Sec.  216.106 of this 
chapter and Sec.  218.16, the Holder of the LOA (hereinafter ``Navy'') 
may incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  218.10(b) by Level A harassment and Level B 
harassment associated with the use of explosives and missile launch 
activities, provided the activity is in compliance with all terms, 
conditions, and requirements of the regulations in this subpart and the 
applicable LOA.
    (b) The incidental take of marine mammals by the activities listed 
in Sec.  218.10(c) is limited to the species and stocks listed in Table 
1 of this section.

                       Table 1 to Sec.   218.12(b)
------------------------------------------------------------------------
         Common name             Scientific name            Stock
------------------------------------------------------------------------
Blue whale..................  Balaenoptera          Eastern North
                               musculus.             Pacific.
Fin whale...................  Balaenoptera          California, Oregon,
                               physalus.             and Washington.
Gray whale..................  Eschrichtius          Eastern North
                               robustus.             Pacific.
Humpback whale..............  Megaptera             California, Oregon,
                               novaeangliae.         Washington.
Minke whale.................  Balaenoptera          California, Oregon,
                               acutorostrata.        and Washington.
Common Bottlenose dolphin...  Tursiops truncatus..  California, Oregon,
                                                     and Washington
                                                     Offshore.
Dall's porpoise.............  Phocoenoides dalli..  California, Oregon,
                                                     and Washington.
Dwarf sperm whale...........  Kogia sima..........  California, Oregon,
                                                     and Washington.
Long-beaked common dolphin..  Delphinus capensis..  California.
Mesoplodont beaked whales     Mesoplodon spp......  California, Oregon,
 \4\.                                                and Washington.
Northern right whale dolphin  Lissodelphis          California, Oregon,
                               borealis.             and Washington.
Pacific white-sided dolphin.  Lagenorhynchus        California, Oregon,
                               obliquidens.          and Washington.
Pygmy killer whale..........  Feresa attenuata....
Pygmy sperm whale...........  Kogia breviceps.....  California, Oregon,
                                                     and Washington.
Risso's dolphins............  Grampus griseus.....  California, Oregon,
                                                     and Washington.
Short-beaked common dolphin.  Delphinus delphis...  California, Oregon,
                                                     and Washington.
Sperm whale.................  Physeter              California, Oregon,
                               macrocephalus.        and Washington.
Striped dolphin.............  Stenella              California, Oregon,
                               coeruleoalba.         and Washington.
Harbor seal.................  Phoca vitulina......  California.
Northern elephant seal......  Mirounga              California.
                               angustirostris.
California sea lion.........  Zalophus              U.S. Stock.
                               californianus.
Guadalupe fur seal..........  Arctocephalus         Mexico to
                               townsendi.            California.
------------------------------------------------------------------------

Sec.  218.13  Prohibitions.

    Notwithstanding incidental takings contemplated in Sec.  218.12(a) 
and authorized by an LOA issued under Sec. Sec.  216.106 of this 
chapter and 218.16, no person in connection with the activities listed 
in Sec.  218.10(c) may:
    (a) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or an LOA issued under Sec. Sec.  216.106 
of this chapter and 218.16;
    (b) Take any marine mammal not specified in Sec.  218.12(b);
    (c) Take any marine mammal specified in Sec.  218.12(b) in any 
manner other than as specified in the LOA issued under Sec. Sec.  
216.106 of this chapter and 218.16;
    (d) Take a marine mammal specified in Sec.  218.12(b) if NMFS 
determines such taking results in more than a negligible impact on the 
species or stock of such marine mammal.


Sec.  218.14  Mitigation requirements.

    When conducting the activities identified in Sec.  218.10(c), the 
mitigation measures contained in any LOA issued under Sec. Sec.  
216.106 of this chapter and 218.16 must be implemented. These 
mitigation measures include, but are not limited to:
    (a) Procedural mitigation. Procedural mitigation is mitigation that 
the Navy must implement whenever and wherever an applicable training or 
testing activity takes place within the PMSR Study Area for each 
applicable activity category or stressor category and includes acoustic 
stressors (i.e., weapons firing noise), explosive stressors (i.e., 
medium-caliber and large-caliber projectiles, missiles and rockets, 
bombs), and physical disturbance and strike stressors (i.e., vessel 
movement; towed in-water devices; small-, medium-, and large-caliber 
non-explosive practice munitions; non-explosive missiles and rockets; 
and non-explosive bombs).
    (1) Environmental awareness and education. Appropriate Navy 
personnel (including civilian personnel) involved in mitigation and 
training or testing reporting under the specified activities will 
complete one or more modules of the U.S Navy Afloat Environmental 
Compliance Training Series, as identified in their career path training

[[Page 37848]]

plan. Modules include: Introduction to the U.S. Navy Afloat 
Environmental Compliance Training Series, Marine Species Awareness 
Training; and U.S. Navy Protective Measures Assessment Protocol.
    (2) Weapons firing noise. Weapons firing noise associated with 
large-caliber gunnery activities.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned on the ship conducting the firing. Depending on the 
activity, the Lookout could be the same as the one provided for under 
``Small-, medium-, and large-caliber non-explosive practice munitions'' 
in paragraph (a)(7)(i) of this section.
    (ii) Mitigation zone and requirements. The mitigation zone must be 
thirty degrees on either side of the firing line out to 70 yd from the 
muzzle of the weapon being fired.
    (A) Prior to the initial start of the activity. Navy personnel must 
observe the mitigation zone for floating vegetation and marine mammals; 
if floating vegetation or marine mammals are observed, Navy personnel 
must relocate or delay the start of weapons firing.
    (B) During the activity. Navy personnel must observe the mitigation 
zone for floating vegetation and marine mammals; if floating vegetation 
or marine mammals are observed, Navy personnel must cease weapons 
firing.
    (C) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing weapons firing) until one of the following 
conditions has been met: The animal is observed exiting the mitigation 
zone; the animal is thought to have exited the mitigation zone based on 
a determination of its course, speed, and movement relative to the 
firing ship; the mitigation zone has been clear from any additional 
sightings for 30 minutes (min); or for mobile activities, the firing 
ship has transited a distance equal to double that of the mitigation 
zone size beyond the location of the last sighting.
    (3) Explosive medium-caliber and large-caliber projectiles. Gunnery 
activities using explosive medium-caliber and large-caliber 
projectiles. Mitigation applies to activities using a surface target.
    (i) Number of Lookouts and observation platform. One Lookout must 
be on the vessel or aircraft conducting the activity. For activities 
using explosive large-caliber projectiles, depending on the activity, 
the Lookout could be the same as the one described in ``Weapons firing 
noise'' in paragraph (a)(2)(i) of this section. If additional platforms 
are participating in the activity, Navy personnel positioned on those 
assets (e.g., safety observers, evaluators) must support observing the 
relevant mitigation zone for marine mammals and other applicable 
biological resources while performing their regular duties.
    (ii) Mitigation zone and requirements. The relevant mitigation 
zones are as follows: 200 yd (182.88 m) around the intended impact 
location for air-to-surface activities using explosive medium-caliber 
projectiles; 600 yd (548.64 m) around the intended impact location for 
surface-to-surface activities using explosive medium-caliber 
projectiles; and 1,000 yd (914.4 m) around the intended impact location 
for surface-to-surface activities using explosive large-caliber 
projectiles.
    (A) Prior to the initial start of the activity (e.g., when 
maneuvering on station). Navy personnel must observe the mitigation 
zone for floating vegetation and marine mammals; if floating vegetation 
or marine mammals are observed, Navy personnel must relocate or delay 
the start of firing.
    (B) During the activity. Navy personnel must observe the mitigation 
zone for floating vegetation and marine mammals; if floating vegetation 
or marine mammals are observed, Navy personnel must cease firing.
    (C) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been met: The animal is observed exiting the mitigation zone; the 
animal is thought to have exited the mitigation zone based on a 
determination of its course, speed, and movement relative to the 
intended impact location; the mitigation zone has been clear from any 
additional sightings for 10 min for aircraft-based firing or 30 min for 
vessel-based firing; or for activities using mobile targets, the 
intended impact location has transited a distance equal to double that 
of the mitigation zone size beyond the location of the last sighting.
    (D) After completion of the activity (e.g., prior to maneuvering 
off station). Navy personnel must, when practical (e.g., when platforms 
are not constrained by fuel restrictions or mission-essential follow-on 
commitments), observe for marine mammals in the vicinity of where 
detonations occurred; if any injured or dead marine mammals are 
observed, Navy personnel must follow established incident reporting 
procedures. If additional platforms are supporting this activity (e.g., 
providing range clearance), Navy personnel on these assets must assist 
in the visual observation of the area where detonations occurred.
    (4) Explosive missiles and rockets. Aircraft-deployed explosive 
missiles and rockets. Mitigation applies to activities using a maritime 
surface target at ranges up to 75 nmi.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned in an aircraft. If additional platforms are participating 
in the activity, Navy personnel positioned on those assets (e.g., 
safety observers, evaluators) must support observing the relevant 
mitigation zone for marine mammals and other applicable biological 
resources while performing their regular duties.
    (ii) Mitigation zone and requirements. The relevant mitigation 
zones are as follows: 900 yd (822.96 m) around the intended impact 
location for missiles or rockets with 0.6-20 lb net explosive weight; 
and 2,000 yd (1,828.8 m) around the intended impact location for 
missiles with 21-500 lb net explosive weight.
    (A) Prior to the initial start of the activity (e.g., during a fly-
over of the mitigation zone). Navy personnel must observe the 
mitigation zone for floating vegetation and marine mammals; if floating 
vegetation or marine mammals are observed, Navy personnel must relocate 
or delay the start of firing.
    (B) During the activity. Navy personnel must observe the mitigation 
zone for floating vegetation and marine mammals; if floating vegetation 
or marine mammals are observed, Navy personnel must cease firing.
    (C) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been met: The animal is observed exiting the mitigation zone; the 
animal is thought to have exited the mitigation zone based on a 
determination of its course, speed, and movement relative to the 
intended impact location; or the mitigation zone has been clear from 
any additional sightings for 10 min when the activity

[[Page 37849]]

involves aircraft that have fuel constraints, or 30 min when the 
activity involves aircraft that are not typically fuel constrained.
    (D) After completion of the activity (e.g., prior to maneuvering 
off station). Navy personnel must, when practical (e.g., when platforms 
are not constrained by fuel restrictions or mission-essential follow-on 
commitments), observe for marine mammals in the vicinity of where 
detonations occurred; if any injured or dead marine mammals are 
observed, Navy personnel must follow established incident reporting 
procedures. If additional platforms are supporting this activity (e.g., 
providing range clearance), Navy personnel on these assets will assist 
in the visual observation of the area where detonations occurred.
    (5) Explosive bombs.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned in an aircraft conducting the activity. If additional 
platforms are participating in the activity, Navy personnel positioned 
on those assets (e.g., safety observers, evaluators) must support 
observing the relevant mitigation zone for marine mammals and other 
applicable biological resources while performing their regular duties.
    (ii) Mitigation zone and requirements. The relevant mitigation 
zones is 2,500 yd (2,286 m) around the intended target.
    (A) Prior to the initial start of the activity (e.g., when arriving 
on station). Navy personnel must observe the mitigation zone for 
floating vegetation and marine mammals; if floating vegetation or 
marine mammals are observed, Navy personnel must relocate or delay the 
start of bomb deployment.
    (B) During the activity (e.g., during target approach). Navy 
personnel must observe the mitigation zone for floating vegetation and 
marine mammals; if floating vegetation or marine mammals are observed, 
Navy personnel must cease bomb deployment.
    (C) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing bomb deployment) until one of the following 
conditions has been met: The animal is observed exiting the mitigation 
zone; the animal is thought to have exited the mitigation zone based on 
a determination of its course, speed, and movement relative to the 
intended target; the mitigation zone has been clear from any additional 
sightings for 10 min; or for activities using mobile targets, the 
intended target has transited a distance equal to double that of the 
mitigation zone size beyond the location of the last sighting.
    (D) After completion of the activity (e.g., prior to maneuvering 
off station). Navy personnel must, when practical (e.g., when platforms 
are not constrained by fuel restrictions or mission-essential follow-on 
commitments), observe for marine mammals in the vicinity of where 
detonations occurred; if any injured or dead marine mammals are 
observed, Navy personnel must follow established incident reporting 
procedures. If additional platforms are supporting this activity (e.g., 
providing range clearance), Navy personnel on these assets must assist 
in the visual observation of the area where detonations occurred.
    (6) Vessel movement. The mitigation will not be required if: The 
vessel's safety is threatened; the vessel is restricted in its ability 
to maneuver (e.g., during launching and recovery of aircraft or landing 
craft, during towing activities, when mooring); the vessel is submerged 
or operated autonomously; or if impracticable based on mission 
requirements (e.g., during Amphibious Assault and Amphibious Raid 
exercises).
    (i) Number of Lookouts and observation platform. One Lookout must 
be on the vessel that is underway.
    (ii) Mitigation zone and requirements. The relevant mitigation 
zones are as follows: 500 yd (457.2 m) around whales; and 200 yd 
(182.88 m) around all other marine mammals (except bow-riding dolphins 
and pinnipeds hauled out on man-made navigational structures, port 
structures, and vessels).
    (A) During the activity. When underway Navy personnel must observe 
the mitigation zone for marine mammals; if marine mammals are observed, 
Navy personnel must maneuver to maintain distance.
    (B) [Reserved]
    (iii) Reporting. If a marine mammal vessel strike occurs, Navy 
personnel must follow the established incident reporting procedures.
    (7) Small-, medium-, and large-caliber non-explosive practice 
munitions. Mitigation applies to activities using a surface target.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned on the platform conducting the activity. Depending on the 
activity, the Lookout could be the same as the one described for 
``Weapons firing noise'' in paragraph (a)(2)(i) of this section.
    (ii) Mitigation zone and requirements. The relevant mitigation zone 
is 200 yd (182.88 m) around the intended impact location.
    (A) Prior to the initial start of the activity (e.g., when 
maneuvering on station). Navy personnel must observe the mitigation 
zone for floating vegetation and marine mammals; if floating vegetation 
or marine mammals are observed, Navy personnel must relocate or delay 
the start of firing.
    (B) During the activity. Navy personnel must observe the mitigation 
zone for floating vegetation and marine mammals; if floating vegetation 
or marine mammals are observed, Navy personnel must cease firing.
    (C) Commencement/recommencement conditions after a marine mammal 
sighting before or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been met: The animal is observed exiting the mitigation zone; the 
animal is thought to have exited the mitigation zone based on a 
determination of its course, speed, and movement relative to the 
intended impact location; the mitigation zone has been clear from any 
additional sightings for 10 min for aircraft-based firing or 30 min for 
vessel-based firing; or for activities using a mobile target, the 
intended impact location has transited a distance equal to double that 
of the mitigation zone size beyond the location of the last sighting.
    (8) Non-explosive missiles and rockets. Aircraft-deployed non-
explosive missiles and rockets. Mitigation applies to activities using 
a maritime surface target at ranges of up to 75 nmi.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned in an aircraft.
    (ii) Mitigation zone and requirements. The relevant mitigation zone 
is 900 yd (822.96 m) around the intended impact location.
    (A) Prior to the initial start of the activity (e.g., during a fly-
over of the mitigation zone). Navy personnel must observe the 
mitigation zone for floating vegetation and marine mammals; if floating 
vegetation or marine mammals are observed, Navy personnel must relocate 
or delay the start of firing.
    (B) During the activity. Navy personnel must observe the mitigation 
zone for floating vegetation and marine mammals; if floating vegetation 
or marine mammals are observed, Navy personnel must cease firing.

[[Page 37850]]

    (C) Commencement/recommencement conditions after a marine mammal 
sighting prior to or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing firing) until one of the following conditions has 
been met: The animal is observed exiting the mitigation zone; the 
animal is thought to have exited the mitigation zone based on a 
determination of its course, speed, and movement relative to the 
intended impact location; or the mitigation zone has been clear from 
any additional sightings for 10 min when the activity involves aircraft 
that have fuel constraints, or 30 min when the activity involves 
aircraft that are not typically fuel constrained.
    (9) Non-explosive bombs. Non-explosive bombs.
    (i) Number of Lookouts and observation platform. One Lookout must 
be positioned in an aircraft.
    (ii) Mitigation zone and requirements. The relevant mitigation zone 
is 900 yd (822.96 m) around the intended target.
    (A) Prior to the initial start of the activity (e.g., when arriving 
on station). Navy personnel must observe the mitigation zone for 
floating vegetation and marine mammals; if floating vegetation or 
marine mammals are observed, Navy personnel must relocate or delay the 
start of bomb deployment.
    (B) During the activity (e.g., during approach of the target or 
intended minefield location). Navy personnel must observe the 
mitigation zone for floating vegetation and marine mammals and, if 
floating vegetation or marine mammals are observed, Navy personnel must 
cease bomb deployment.
    (C) Commencement/recommencement conditions after a marine mammal 
sighting prior to or during the activity. Navy personnel must allow a 
sighted marine mammal to leave the mitigation zone prior to the initial 
start of the activity (by delaying the start) or during the activity 
(by not recommencing bomb deployment) until one of the following 
conditions has been met: The animal is observed exiting the mitigation 
zone; the animal is thought to have exited the mitigation zone based on 
a determination of its course, speed, and movement relative to the 
intended target or minefield location; the mitigation zone has been 
clear from any additional sightings for 10 min; or for activities using 
mobile targets, the intended target has transited a distance equal to 
double that of the mitigation zone size beyond the location of the last 
sighting.
    (10) Target and Missile Launches from San Nicolas Islands (SNI). 
Target and missile launch activities from SNI.
    (i) Mitigation zone and requirements. 305 m (1,000 ft) over 
pinniped haulouts. Missiles must not cross over pinniped haulouts at 
elevations less than 305 m (1,000 ft) above the haulout. All manned 
aircraft and helicopter flight paths must maintain a minimum distance 
of 305 m (1,000 ft) from recognized seal haulouts and rookeries, except 
in emergencies or for real-time security incidents. For unmanned 
aircraft systems (UAS), the following minimum altitudes must be 
maintained over pinniped haulout areas and rookeries: Class 0-2 UAS 
must maintain a minimum altitude of 300 ft; Class 3 UAS must maintain a 
minimum altitude of 500 ft; Class 4 or 5 UAS must not be flown below 
1,000 ft.
    (A) Pinniped haulouts. Navy personnel must not enter pinniped 
haulouts or rookeries. Personnel may be adjacent to pinniped haulouts 
and rookeries prior to and following a launch for monitoring purposes.
    (B) Number of Launch events. Navy must not conduct more than 40 
launch events annually. Up to 10 launch events of the 40 annual launch 
events may occur at night.
    (C) Launches during the peak pinniped pupping season. Launches must 
be scheduled to avoid peak pinniped pupping periods between January and 
July, to the maximum extent practicable.
    (D) Unauthorized species. If a species for which authorization has 
not been granted is taken, or a species for which authorization has 
been granted but the authorized takes are met, the Navy must consult 
with NMFS to determine how to proceed.
    (E) Review of launch procedures. The Navy must review the launch 
procedure and monitoring methods, in cooperation with NMFS, if any 
incidents of injury or mortality of a pinniped are discovered during 
post-launch surveys, or if surveys indicate possible effects to the 
distribution, size, or productivity of the affected pinniped 
populations as a result of the specified activities. If necessary, 
appropriate changes must be made through modification to this LOA prior 
to conducting the next launch of the same vehicle.
    (ii) [Reserved]
    (b) Seasonal awareness messages. In addition to procedural 
mitigation, Navy personnel must implement seasonal awareness 
notification messages throughout the PMSR Study Area to avoid 
interaction with large whales during transit.
    (1) Blue Whale Awareness Notification Message.
    (i) Navy personnel must issue a seasonal awareness notification 
message to alert Navy ships and aircraft operating throughout the PMSR 
Study Area to the possible presence of increased concentrations of blue 
whales June 1 through October 31.
    (ii) To maintain safety of navigation and to avoid interactions 
with large whales during transits, Navy personnel must instruct vessels 
to remain vigilant to the presence of blue whales that, when 
concentrated seasonally, may become vulnerable to vessel strikes.
    (iii) Navy personnel must use the information from the awareness 
notification message to assist their visual observation of applicable 
mitigation zones during training and testing activities and to aid in 
the implementation of procedural mitigation.
    (2) Gray Whale Awareness Notification Message.
    (i) Navy personnel must issue a seasonal awareness notification 
message to alert Navy ships and aircraft operating through the PMSR 
Study Area to the possible presence of increased concentrations of gray 
whales November 1 through March 31.
    (ii) To maintain safety of navigation and to avoid interactions 
with large whales during transits, Navy personnel must instruct vessels 
to remain vigilant to the presence of gray whales that, when 
concentrated seasonally, may become vulnerable to vessel strikes.
    (iii) Navy personnel must use the information from the awareness 
notification message to assist their visual observation of applicable 
mitigation zones during training and testing activities and to aid in 
the implementation of procedural mitigation.
    (3) Fin Whale Awareness Notification Message.
    (i) Navy personnel must issue a seasonal awareness notification 
message to alert Navy ships and aircraft operating throughout the PMSR 
Study Area to the possible presence of increased concentrations of fin 
whales November 1 through May 31.
    (ii) To maintain safety of navigation and to avoid interactions 
with large whales during transits, Navy personnel must instruct vessels 
to remain vigilant to the presence of fin whales that, when 
concentrated seasonally, may become vulnerable to vessel strikes.
    (iii) Navy personnel must use the information from the awareness 
notification message to assist their visual observation of applicable 
mitigation zones during training and testing activities and to aid in 
the

[[Page 37851]]

implementation of procedural mitigation.


Sec.  218.15  Requirements for monitoring and reporting.

    (a) Unauthorized take. Navy personnel must notify NMFS immediately 
(or as soon as operational security considerations allow) if the 
specified activity identified in Sec.  218.10 is thought to have 
resulted in the serious injury or mortality of any marine mammals, or 
in any Level A harassment or Level B harassment of marine mammals not 
identified in this subpart.
    (b) Monitoring and reporting under the LOA. The Navy must conduct 
all monitoring and reporting required under the LOA. The Navy will 
coordinate and discuss with NMFS how monitoring in the PMSR Study Area 
could contribute to the Navy's Marine Species Monitoring Program.
    (c) Notification of injured, live stranded, or dead marine mammals. 
Navy personnel must consult the Notification and Reporting Plan, which 
sets out notification, reporting, and other requirements when dead, 
injured, or live stranded marine mammals are detected. The Notification 
and Reporting Plan is available at https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-testing-and-training-activities-point-mugu-sea-range.
    (d) Pinniped Monitoring Plan on SNI. In consultation with NMFS, the 
Navy will implement a monitoring plan for beaches exposed to missile 
launch noise with the goal of assessing baseline pinniped distribution/
abundance and potential changes in pinniped use of these beaches after 
launch events. Marine mammal monitoring shall include multiple surveys 
(e.g. time-lapse photography) during the year that record the species, 
number of animals, general behavior, presence of pups, age class, 
gender and reactions to launch noise or other natural or human caused 
disturbances, in addition to environmental conditions that may include 
tide, wind speed, air temperature, and swell. In addition, video and 
acoustic monitoring of up to three pinniped haulout areas and rookeries 
must be conducted during launch events that include missiles or targets 
that have not been previously monitored using video and acoustic 
recorders for at least three launch events.
    (e) Annual Pinniped Monitoring Report on SNI. The Navy must submit 
an annual report to NMFS of the SNI rocket and missile launch 
activities. The draft annual monitoring report must be submitted to the 
Director, Office of Protected Resources, NMFS, within three months 
after the end of the calendar year. NMFS will submit comments or 
questions on the draft monitoring report, if any, within three months 
of receipt. The report will be considered final after the Navy has 
addressed NMFS' comments, or three months after the submission of the 
draft if NMFS does not provide comments on the draft report. The report 
will summarize the launch events conducted during the year; assess any 
direct impacts to pinnipeds from launch events; assess any cumulative 
impacts on pinnipeds from launch events; and, summarize pinniped 
monitoring and research activities conducted on SNI and any findings 
related to effects of launch noise on pinniped populations.
    (f) Annual PMSR Study Area Training and Testing Activity Report. 
Each year, the Navy must submit a detailed report PMSR (Annual Training 
and Testing Activity Report) to the Director, Office of Protected 
Resources, NMFS, within three months after the one-year anniversary of 
the date of issuance of the LOA. NMFS will submit comments or questions 
on the report, if any, within one month of receipt. The report will be 
considered final after the Navy has addressed NMFS' comments, or one 
month after submission of the draft if NMFS does not provide comments 
on the draft report. The annual report will contain information on all 
sound sources used (total hours or quantity of each bin; total annual 
number of each type of explosive events; and total annual expended/
detonated rounds (missiles, bombs, etc.) for each explosive bin). The 
annual report will also contain both the current year's data as well as 
explosive use quantity from previous years' reports. Additionally, if 
there were any changes to the explosive allowance in a given year, or 
cumulatively, the report will include a discussion of why the change 
was made and include analysis to support how the change did or did not 
affect the analysis in the 2021 PMSR FEIS/OEIS and MMPA final rule. The 
annual report will also include the details regarding specific 
requirements associated with monitoring on SNI. The final annual/close-
out report at the conclusion of the authorization period (year seven) 
will serve as the comprehensive close-out report and include both the 
final year annual use compared to annual authorization as well as a 
cumulative seven-year annual use compared to seven-year authorization. 
The detailed reports must contain the information identified in 
paragraphs (e)(1) through (6) of this section.
    (1) Explosives. This section of the report must include the 
following information for explosive activities completed that year.
    (i) Activity information gathered for each explosive event.
    (A) Location by Special Use Airspace (e.g., Warning Area).
    (B) Date and time exercise began and ended.
    (C) Total hours of observation by Lookouts before, during, and 
after exercise.
    (D) Total annual expended/detonated ordnance (i.e., missile, bombs 
etc.) number and types of explosive source bins detonated.
    (E) Wave height in feet (high, low, and average) during exercise.
    (F) Narrative description of sensors and platforms utilized for 
marine mammal detection and timeline illustrating how marine mammal 
detection was conducted.
    (ii) Individual marine mammal observation (by Navy Lookouts) 
information for each sighting where mitigation was implemented.
    (A) Date/Time/Location of sighting.
    (B) Species (if not possible, indicate whale or dolphin).
    (C) Number of individuals.
    (D) Initial detection sensor (e.g., sonar or Lookout).
    (E) Length of time observers maintained visual contact with marine 
mammal.
    (F) Sea state.
    (G) Visibility.
    (H) Whether sighting was before, during, or after detonations/
exercise, and how many minutes before or after.
    (I) Distance of marine mammal from actual detonations (or target 
spot if not yet detonated): Less than 200 yd, 200 to 500 yd, 500 to 
1,000 yd, 1,000 to 2,000 yd, or greater than 2,000 yd.
    (J) Lookouts must report, in plain language and without trying to 
categorize in any way, the observed behavior of the animal(s) (such as 
animal closing to bow ride, paralleling course/speed, floating on 
surface and not swimming etc.), including speed and direction and if 
any calves were present.
    (K) The report must indicate whether explosive detonations were 
delayed, ceased, modified, or not modified due to marine mammal 
presence and for how long.
    (L) If observation occurred while explosives were detonating in the 
water, indicate munition type in use at time of marine mammal 
detection.
    (2) Summary of sources used. This section of the report must 
include the following information summarized from the authorized sound 
sources used in all training and testing events:

[[Page 37852]]

    (i) Total annual quantity (per the LOA) of each explosive bin; and
    (ii) Total annual expended/detonated ordnance (missiles, bombs, 
etc.) for each explosive bin.
    (h) Final Close-Out Report. The final (year seven) draft annual/
close-out report must be submitted within three months after the 
expiration of this subpart to the Director, Office of Protected 
Resources, NMFS. NMFS must submit comments on the draft close-out 
report, if any, within three months of receipt. The report will be 
considered final after the Navy has addressed NMFS' comments, or three 
months after the submittal of the draft if NMFS does not provide 
comments.


Sec.  218.16  Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to the regulations 
in this subpart, the Navy must apply for and obtain an LOA in 
accordance with Sec.  216.106 of this chapter.
    (b) An LOA, unless suspended or revoked, may be effective for a 
period of time not to exceed between October 31, 2021, and October 30, 
2028.
    (c) If an LOA expires prior to October 30, 2028, the Navy may apply 
for and obtain a renewal of the LOA.
    (d) In the event of projected changes to the activity or to 
mitigation, monitoring, or reporting (excluding changes made pursuant 
to the adaptive management provision of Sec.  218.17(c)(1)) required by 
an LOA issued under this subpart, the Navy must apply for and obtain a 
modification of the LOA as described in Sec.  218.17.
    (e) Each LOA will set forth:
    (1) Permissible methods of incidental taking;
    (2) Geographic areas for incidental taking;
    (3) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species or stocks of marine mammals and their 
habitat; and
    (4) Requirements for monitoring and reporting.
    (f) Issuance of the LOA(s) must be based on a determination that 
the level of taking is consistent with the findings made for the total 
taking allowable under the regulations in this subpart.
    (g) Notice of issuance or denial of the LOA(s) will be published in 
the Federal Register within 30 days of a determination.


Sec.  218.17  Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec. Sec.  216.106 of this chapter and 
218.16 for the activity identified in Sec.  218.10(c) may be renewed or 
modified upon request by the applicant, provided that:
    (1) The proposed specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as 
those described and analyzed for the regulations in this subpart 
(excluding changes made pursuant to the adaptive management provision 
in paragraph (c)(1) of this section); and
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA(s) were implemented.
    (b) For LOA modification or renewal requests by the applicant that 
include changes to the activity or to the mitigation, monitoring, or 
reporting measures (excluding changes made pursuant to the adaptive 
management provision in paragraph (c)(1) of this section) that do not 
change the findings made for the regulations or result in no more than 
a minor change in the total estimated number of takes (or distribution 
by species or years), NMFS may publish a notice of proposed LOA in the 
Federal Register, including the associated analysis of the change, and 
solicit public comment before issuing the LOA.
    (c) An LOA issued under Sec. Sec.  216.106 of this chapter and 
218.16 may be modified by NMFS under the following circumstances:
    (1) Adaptive management. After consulting with the Navy regarding 
the practicability of the modifications, NMFS may modify (including 
adding or removing measures) the existing mitigation, monitoring, or 
reporting measures if doing so creates a reasonable likelihood of more 
effectively accomplishing the goals of the mitigation and monitoring.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, or reporting measures in an LOA 
include:
    (A) Results from the Navy's annual monitoring report and annual 
exercise report from the previous year(s);
    (B) Results from other marine mammal and/or sound research or 
studies;
    (C) Results from specific stranding investigations; or
    (D) Any information that reveals marine mammals may have been taken 
in a manner, extent, or number not authorized by the regulations in 
this subpart or subsequent LOAs.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
will publish a notice of a new proposed LOA in the Federal Register and 
solicit public comment.
    (2) Emergencies. If NMFS determines that an emergency exists that 
poses a significant risk to the well-being of the species of marine 
mammals specified in LOAs issued pursuant to Sec. Sec.  216.106 of this 
chapter and 218.16, an LOA may be modified without prior notice or 
opportunity for public comment. Notice will be published in the Federal 
Register within thirty days of the action.


Sec.  218.18  [Reserved]


Sec.  218.19  [Reserved]

[FR Doc. 2021-14542 Filed 7-15-21; 8:45 am]
BILLING CODE 3510-22-P