[Federal Register Volume 90, Number 214 (Friday, November 7, 2025)]
[Rules and Regulations]
[Pages 50504-50722]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-19806]
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Vol. 90
Friday,
No. 214
November 7, 2025
Part II
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Part 218
Takes of Marine Mammals Incidental to Specified Activities; Taking
Marine Mammals Incidental to Military Readiness Activities in the
Atlantic Fleet Training and Testing Study Area; Final Rule
Federal Register / Vol. 90, No. 214 / Friday, November 7, 2025 /
Rules and Regulations
[[Page 50504]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 218
[Docket No. 251030-0166]
RIN 0648-BN17
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Military Readiness Activities in
the Atlantic Fleet Training and Testing Study Area
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Final rule; notification of issuance of letters of
authorization.
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SUMMARY: NMFS, upon request from the U.S. Department of the Navy
(including the U.S. Navy and the U.S. Marine Corps (Navy)) and on
behalf of the U.S. Coast Guard (Coast Guard; hereafter, Navy and Coast
Guard are collectively referred to as Action Proponents), issues these
regulations pursuant to the Marine Mammal Protection Act (MMPA) to
govern the taking of marine mammals incidental to training and testing
activities conducted in the Atlantic Fleet Training and Testing (AFTT)
Study Area over the course of 7 years from November 2025 through
November 2032. These regulations, which allow for the issuance of
letters of authorization (LOAs) for the incidental take of marine
mammals during specified activities and timeframes, prescribe the
permissible methods of taking and other means of effecting the least
practicable adverse impact on marine mammal species and their habitat,
and establish requirements pertaining to the monitoring and reporting
of such taking. The Action Proponents' activities are considered
military readiness activities pursuant to the MMPA, as amended by the
National Defense Authorization Act for Fiscal Year 2004 (2004 NDAA) and
the NDAA for Fiscal Year 2019 (2019 NDAA).
DATES: Effective from November 14, 2025, through November 13, 2032.
ADDRESSES: A copy of the Action Proponents' incidental take
authorization (ITA) application and supporting documents, NMFS'
proposed and final rules and subsequent LOAs for these regulations, as
well as a list of the references cited in this document, may be
obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. In case of problems accessing these documents, please call
the contact listed below (see FOR FURTHER INFORMATION CONTACT).
FOR FURTHER INFORMATION CONTACT: Alyssa Clevenstine, Office of
Protected Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Purpose and Need for Regulatory Action
These regulations, issued under the authority of the MMPA (16
U.S.C. 1361 et seq.), allow for the authorization of take of marine
mammals incidental to the Action Proponents' training and testing
activities (which qualify as military readiness activities) involving
the use of active sonar and other transducers, air guns, and explosives
(including in-water explosives and underwater detonations); pile
driving and vibratory extraction; and vessel movement in the AFTT Study
Area. The AFTT Study Area includes air and water space of the western
Atlantic Ocean along the east coast of North America, the Gulf of
America (formerly Gulf of Mexico), and portions of the Caribbean Sea,
covering approximately 2.6 million square nautical miles (nmi\2\; 8.9
million square kilometers (km\2\)) of ocean area (see figure 1.1-1 of
the application). Please see the Legal Authority for the Final Action
section for relevant definitions.
Legal Authority for the Final Action
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Section 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et
seq.) directs the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are proposed 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 comment.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking; other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the monitoring and
reporting of the takings. The MMPA defines ``take'' to mean to harass,
hunt, capture, or kill, or attempt to harass, hunt, capture, or kill
any marine mammal. The Analysis and Negligible Impact Determination
section discusses the definition of ``negligible impact.''
The 2004 NDAA (Pub. L. 108-136) amended section 101(a)(5) of the
MMPA to remove the ``small numbers'' and ``specified geographical
region'' provisions and amended the definition of ``harassment'' as
applied to a ``military readiness activity'' to read as follows
(section 3(18)(B) of the MMPA): (i) Any act that injures or has the
significant potential to injure a marine mammal or marine mammal stock
in the wild (Level A Harassment); or (ii) Any act that disturbs or is
likely to disturb a marine mammal or marine mammal stock in the wild by
causing disruption of natural behavioral patterns, including, but not
limited to, migration, surfacing, nursing, breeding, feeding, or
sheltering, to a point where such behavioral patterns are abandoned or
significantly altered (Level B Harassment). The 2004 NDAA also amended
section 101(a)(5)(A)(iii) of the MMPA, establishing that ``[f]or
military readiness activity . . . , a determination of `least
practicable adverse impact' . . . shall include consideration of
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.'' On August 13, 2018,
the 2019 NDAA (Pub. L. 115-232) amended section 101(a)(5)(A)(ii) of the
MMPA to allow incidental take regulations for military readiness
activities to be issued for up to 7 years.
Summary of Major Provisions Within the Final Rule
The major provisions of this rule are:
Take of marine mammals by Level A harassment and/or Level
B harassment;
Take of marine mammals by mortality or serious injury (M/
SI);
Use of defined powerdown and shutdown zones (based on
activity);
Measures to reduce the likelihood of vessel strikes;
Activity limitations in certain areas and times that are
biologically important (i.e., for foraging, migration, reproduction)
for marine mammals;
Implementation of a Notification and Reporting Plan (for
dead, live
[[Page 50505]]
stranded, or marine mammals struck by any vessel engaged in military
readiness activities); and
Implementation of a robust monitoring plan to improve our
understanding of the environmental effects resulting from the Action
Proponents' training and testing activities.
This rule includes an adaptive management component that allows for
timely modification of mitigation, monitoring, and/or reporting
measures based on new information, when appropriate.
Summary of Request
On May 28, 2024, NMFS received an application from the Action
Proponents requesting authorization to take marine mammals, by Level A
and Level B harassment, incidental to training and testing
(characterized as military readiness activities) including the use of
sonar and other transducers, explosives, air guns, and impact and
vibratory pile driving and extraction conducted within the AFTT Study
Area. In addition, the Action Proponents requested authorization to
take, by serious injury or mortality, a limited number of several
marine mammal species incidental to use of explosives, ship shock
trials, and vessel movement during military readiness activities
conducted within the AFTT Study Area over the 7-year period of the
LOAs. In response to our comments and following information exchange,
the Action Proponents submitted a final revised application on August
16, 2024, that we determined was adequate and complete on August 19,
2024. On September 20, 2024, we published a notice of receipt (NOR) of
application in the Federal Register (89 FR 77106), requesting comments
and information related to the Action Proponents' specified activities.
During the 30-day public comment period, we did not receive any public
comments. On October 8, 2024, the Action Proponents submitted an
updated application to revise take estimates for a subset of Navy
activities. On January 21, 2025, the Action Proponents submitted an
updated application which removed ship shock trials and estimated take
associated with that activity within the Virginia Capes (VACAPES) Range
Complex. On February 13, 2025, the Action Proponents submitted an
updated application containing minor revisions. On May 9, 2025, we
published a proposed rule (90 FR 19858) and requested comments and
information related to the Action Proponents' request for 30 days. All
relevant comments received during the proposed rulemaking comment
period were considered in this final rule. Comments received on the
proposed rule are addressed in this final rule in the Comments and
Responses section.
NMFS has previously promulgated incidental take regulations
pursuant to the MMPA relating to similar military readiness activities
in the AFTT Study Area. NMFS published the first rule effective from
January 22, 2009 through January 22, 2014 (74 FR 4844, January 27,
2009), the second rule effective from November 14, 2013 through
November 13, 2018 (78 FR 73009, December 4, 2013), and the third rule
effective from November 14, 2018 through November 13, 2023 (83 FR
57076, November 14, 2018), which was subsequently amended, extending
the effective date through November 13, 2025 (84 FR 70712, December 23,
2019) pursuant to the 2019 NDAA. For this rulemaking, the Action
Proponents plan to conduct substantially similar training and testing
activities within the AFTT Study Area that were conducted under
previous rules.
The Action Proponents' 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 this rule account for interannual variability in
training and testing to meet evolving or emergent military readiness
requirements. These regulations cover military readiness activities in
the AFTT Study Area that will occur for a 7-year period following the
expiration of the pre-existing MMPA authorization after November 13,
2025.
Description of Specified Activity
The Action Proponents requested authorization to take marine
mammals incidental to conducting military readiness activities. The
Action Proponents have determined that acoustic and explosives
stressors are most likely to result in take of marine mammals in the
form of Level A and B harassment, and a limited number of takes by
serious injury or mortality may result from vessel movement and
explosive use including ship shock trials. NMFS concurs with these
determinations. Detailed descriptions of these activities are provided
in chapter 2 of the 2025 AFTT Supplemental Environmental Impact
Statement (EIS)/Overseas EIS (OEIS) (2025 AFTT Supplemental EIS/OEIS)
(https://www.nepa.navy.mil/aftteis/) and in the Action Proponents'
application (https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities).
A detailed description of the specified activities was provided in
our proposed rule (90 FR 19858, May 9, 2025). NMFS hereby refers to the
information and analysis provided in the proposed rule which continue
to apply to this final rule. Since that time, no changes have been made
to the planned activities. Therefore, a detailed description is not
provided here. Please refer to the proposed rulemaking for the complete
description of the specified activity.
Foreign Navies
In furtherance of national security objectives, foreign militaries
may participate in multinational training and testing events in the
AFTT Study Area. Foreign military activities that are planned by and
under the substantial control and responsibility of the Action
Proponents are included in the specified activity. These participants
could be in various training or testing events described in appendix A
of the 2025 AFTT Supplemental EIS/OEIS, and their effects are analyzed
in this final rule. However, when foreign military vessels and aircraft
operate independently within the study area as sovereign vessels
outside the planning, control, and responsibility of the Action
Proponents, those activities are not considered part of the specified
activity. There are many reasons why foreign military vessels may
traverse U.S. waters or come into a U.S. port, not all of which are at
the request of any of the Action Proponents. Foreign military vessels
and aircraft operate pursuant to their own national authorities and
have independent rights under customary international law, embodied in
the principle of sovereign immunity, to engage in various activities on
the world's oceans and seas.
When foreign militaries are participating in a U.S. Navy-led
exercise or event, foreign military use of sonar and explosives, when
combined with the Action Proponents' use of sonar and explosives, would
not result in exceedance of the analyzed levels (within each Navy
Acoustic Effects Model (NAEMO) modeled sonar and explosive bin) used
for estimating predicted impacts, which formed the basis of our
acoustic impacts effects analysis that was used to estimate take in
this final rule. Please see the Mitigation Measures section and
Reporting section of this final rule for information about mitigation
and reporting related to foreign navy activities in the AFTT Study
Area.
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Comments and Responses
We published the proposed rule in the Federal Register on May 9,
2025 (90 FR 19858) with a 30-day comment period. In that proposed rule,
we requested public input on our analyses, our preliminary findings,
and the proposed regulations, and requested that interested persons
submit relevant information and comments. During the 30-day comment
period, we received 1,216 comments. Of this total, one submission was
from the Marine Mammal Commission (Commission), two were from non-
governmental organizations Natural Resources Defense Council and Turtle
Island Restoration Network, and the remaining comments were from
private citizens. The majority of these comments were form letter
submissions containing identical or nearly identical content expressing
general opposition toward the Action Proponents' proposed training and
testing activities and requesting that NMFS not issue the regulations
and LOAs, but the commenters provided no specific recommendations or
supporting information. These general comments have been noted, but
because they did not include information pertinent to NMFS' decision,
they are not addressed further.
NMFS has reviewed and considered all relevant public comments
received on the proposed rule and issuance of the LOAs. All
substantive, relevant comments and our responses are described below.
We organize our comment responses by major categories.
Impact Analysis and Thresholds
Comment 1: The Commission stated that a 5-minute accumulation time
for an entire day of pile driving is insufficient, particularly because
of the Commission's assertion that the Navy does not implement, and
NMFS has not proposed to require, soft-start procedures during pile-
driving training activities. The Commission also noted differences in
pile driving between the proposed rule and another recent military
readiness activity involving pile driving (90 FR 20283, May 13, 2025).
The Commission recommended that NMFS revise: (1) the range to effects
for pile driving for temporary threshold shift (TTS) and auditory
injury (AUD INJ) based on the number of piles of each pile type and
installation method that would be installed on a given day, the number
of minutes or strikes needed to install each pile to depth, and the
correct source levels, including for vibratory installation of 24-inch
(0.61 meter (m)) sheet piles; (2) the range to effects for pile driving
for behavioral response for vibratory installation of 24-inch (0.61 m)
sheet piles based on a source level of 159 decibel referenced to 1
microPascal (dB re 1 [mu]Pa) at 11 m; and (3) the numbers of takes
accordingly for the final rule.
Response: NMFS disagrees with the Commission's assertion that the
source levels used for vibratory installation of 24-inch (0.61 m) sheet
piles are incorrect. As indicated in the proposed rule and the
technical report ``Quantifying Acoustic Impacts on Marine Mammals and
Sea Turtles: Methods and Analytical Approach for Phase IV Training and
Testing'' (U.S. Department of the Navy, 2024b), hereafter referred to
as the Acoustic Impacts Technical Report, a source level of 159 dB
root-means-square (RMS) for vibratory driving of 24-inch (0.61 m) steel
sheet piles measured at 10 m (32.8 feet (ft)) (NAVFAC, 2020) is a
reasonable representation of likely sound levels.
The Navy assumed, and NMFS concurred, that most animals in the area
of pile driving activities would avoid higher sound levels that could
cause injury over periods of time shorter than 5 minutes. The Navy is
required to shut down pile driving if a bottlenose dolphin occurs
within 100 yards (yd) (91.4 m) of the pile driving site. Since pile
driving occurs in relatively calm, shallow, coastal waters, and
Lookouts are on stationary platforms (e.g., elevated piers, bulkhead
walls), there is a high likelihood that marine mammals would be sighted
within or approaching the 100 yd (91.4 m) shutdown zone and mitigation
would be implemented, therefore preventing potential TTS or AUD INJ, as
all the predicted ranges for these effects are significantly smaller
than 100 yd (91.4 m). As such, Level A harassment from pile driving
activities is neither anticipated nor authorized, consistent with the
proposed rule.
Navy considers soft-start procedures for impact pile driving to be
part of its standard operating procedures. As such, neither the 2024
AFTT Draft Supplemental EIS/OEIS, application, nor the AFTT proposed
rule (90 FR 19858, May 9, 2025) listed soft start as a mitigation
measure. Navy states that its standard operating procedures are
essential to safety and mission success and are implemented regardless
of their secondary benefits, whereas its mitigation measures are
designed entirely for the purpose of avoiding or reducing impacts on
marine mammals. As such, the Action Proponents did not include a
description of the soft-start procedure in the mitigation section of
the application, and NMFS did not propose to include soft start as a
mitigation measure in the proposed rule. However, NMFS agrees with the
Commission that it is appropriate to require soft-start procedures as a
mitigation measure, and this final rule clarifies that the Navy must
implement soft start techniques for impact pile driving. Of note, Navy
continues to consider soft-start procedures as part of their standard
operating procedures, and as such, they are not listed as a mitigation
measure in the 2025 AFTT Supplemental EIS/OEIS.
Comment 2: The Commission recommended that NMFS work with the Navy
to use an avoidance swim speed of no more than 2 meters per second (m/
second) for harbor porpoises and 1 m/second for pinnipeds, and to
revise the NAEMO modeling and take estimates appropriately for the
final rule. The Commission further recommended that NMFS work with the
Navy to incorporate moving animats (i.e., a virtual animal) into NAEMO
that can actively avoid sound sources based on species-specific dive
profiles and swim speeds for Phase V activities (which would occur in
AFTT from 2032 to 2039) and, if that is not feasible, incorporate
species-specific swim speeds and the actual modeled sound propagation
into NAEMO to simulate avoidance for a given event. The Commission
stated that both creating an emulator and running simulation studies
outside of NAEMO, as recommended by Simmons et al. (2025), should
inform how best to deal with moving animats and implementing avoidance
within NAEMO.
Response: NMFS and the Navy acknowledge the importance of using
appropriate swim speeds in the avoidance analysis in NAEMO, which
assesses the potential for marine mammals to mitigate high-intensity
sound exposures that could lead to auditory injury. While baseline swim
speeds can be informative, the Navy prioritized data on swim behavior
observed near and during anthropogenic disturbance because these data
were considered more representative of how animals might respond to
acoustic stimuli and potentially reduce injury risk. NMFS concurs with
this approach.
The Commission referenced a study by Kastelein et al. (2018) as
support for a lower harbor porpoise swim speed. However, the cited
speed of 7.1 kilometers per hour (km/hr) represents the sustained
average speed of a single captive harbor porpoise in a relatively small
pool during a pile driving playback study at exposures below those
causing auditory injury. This specific observation does not accurately
reflect the full range of harbor porpoise swim capabilities. As
documented in
[[Page 50507]]
table 8 of the appendix to the Acoustic Impacts Technical Report, data
from free-swimming harbor porpoises indicate swim speeds up to and
exceeding 3 m/second, supporting the Navy's chosen value for modeling
avoidance.
For pinnipeds, the avoidance analysis used a reasonable swim speed
of 2 m/second for a limited duration (10 minutes), acknowledging the
lack of observed data on their swim behavior during acoustic exposures.
This assumption balances the need for a realistic representation of
potential avoidance behavior with the limited data availability,
contributing to a conservative assessment of potential impacts.
The Navy's approach to modeling impacts is described in the
Acoustic Impacts Technical Report. NMFS has reviewed the Acoustic
Impacts Technical Report and concurs with Navy that the approach is
based on the best available science. In early NAEMO development, the
Navy compared the number of exposures (i.e., >120 dB) using the Marine
Mammal Movement and Behavior (3MB) model versus horizontally stationary
animats and concluded that there was no significant difference in
behavioral exposures between the two distribution methods. Thus,
horizontally stationary animats were selected for computational
efficiency.
NMFS and the Navy recognize the evolving nature of modeling
techniques and acknowledge the Commission's desire for more dynamic and
species-specific avoidance behaviors in future iterations of NAEMO.
NMFS has encouraged the Navy to continue to explore NAEMO enhancements,
and the Navy has indicated that it will consider species-specific swim
speeds and potentially more complex movement models, as data
availability and computational capabilities allow. Currently, however,
detailed avoidance data for many species are limited, necessitating the
use of surrogate data and generalized approaches, as is also the case
with dive profiles.
The Navy states that it will continue to prioritize research and
development efforts to enhance the accuracy of its impact modeling
tools, ensuring the best available science informs its environmental
assessments.
Comment 3: The Commission recommended that NMFS work with the Navy
to use NAEMO to conduct modeling of both multi-day events and multiple
single-day events to estimate the number of repeated exposures an
individual is expected to incur and to better assess repeated exposures
of individuals and population-level consequences, rather than rely on
what it called a qualitative assessment. The Commission cited Simmons
et al. (2025) recommendation of ways that NAEMO and results from NAEMO
could be better used to estimate repeated takes and population-level
impacts.
Response: NMFS and the Navy have had ongoing discussions about how
to better assess and characterize the number of repeated takes of
individuals from training and testing activities, including whether
NAEMO could be used to generate estimates of repeated takes of
individuals. A credible assessment of the repeated takes due to the
specified activities per the approach suggested in the comment would
require treating animats as unique individuals over the course of a
year's activity and across a large study area, while incorporating
migration patterns and nomadic movement. Such an effort would be
computationally intensive and Navy anticipates that it is likely
infeasible given reasonable resources. In contrast, the action analyzed
by Zeddies et al. (2017) and referenced by the Commission in supporting
statements was less complex than the specified activities. Thus,
Zeddies et al. (2017) could assess repeated takes within spatially and
temporally limited areas with undirected animal ingress/egress. NMFS
will continue to work with the Navy to better assess and characterize
the number of repeated takes of individuals. Of note, Simmons et al.
(2025), referenced by the Commission, was written after a joint
workshop with the Navy and SMRU Consulting. Recommendations from the
workshop and associated report are being considered for future modeling
improvements.
While NMFS and the Action Proponents' analyses could be further
refined, the information in NMFS' analysis is sufficient for assessing
whether the authorized take would have a negligible impact on the
species or stocks of marine mammals, and it is not necessary to have
exact number of times that an animal is estimated to be repeatedly
taken in order to make the determination. As described in the
Preliminary Analysis and Negligible Impact Determination section of the
proposed rule (90 FR 19858, May 9, 2025) and this final rule, generally
speaking, the higher the number of takes as compared to the population
abundance, the more repeated takes of individuals are likely, and the
higher the actual percentage of individuals in the population that are
likely taken at least once in a year. We look at this comparative
metric (number of takes to population abundance) to give us a relative
sense of where a larger portion of a species is being taken by the
specified activities, where there is a likelihood that the same
individuals are being taken across multiple days, and whether the
number of days might be higher or more likely sequential. Where the
number of instances of take is less than 100 percent of the abundance,
and there is no information to specifically suggest that some subset of
animals is known to congregate in an area in which activities are
regularly occurring (e.g., a small resident population, takes occurring
in a known important area such as a Biologically Important Area (BIA),
or a large portion of the takes occurring in a certain region and
season), the overall likelihood and number of repeated takes is
generally considered low, as it could, on one extreme, mean that every
take represents a separate individual in the population being taken on
1 day (a minimal impact to an individual) or, more likely, that some
smaller number of individuals are taken on 1 day annually and some are
taken on a few, not likely sequential, days annually, and of course
some are not taken at all.
In the ocean, the use of sonar and other active acoustic sources is
often transient and is unlikely to repeatedly expose the same
individual animals within a short period, for example, within one
specific exercise. However, for some individuals of some species,
repeated exposures across different activities could occur over the
year, especially where events occur in generally the same area with
more resident species. In short, for some species, we expect that the
total anticipated takes represent exposures of a smaller number of
individuals of which some would be exposed multiple times, but based on
the nature of the specified activities and the movement patterns of
marine mammals, it is unlikely that individuals from most stocks would
be taken over more than a few days within a given year. This means that
even where repeated takes of individuals are likely to occur, they are
more likely to result from non-sequential exposures from different
activities, and, even if sequential, individual animals are not
predicted to be taken for more than several days in a row, at most. As
described elsewhere, the nature of the majority of the exposures would
be expected to be of a less severe nature, and based on the numbers, it
is likely that any individual exposed multiple times is still taken on
only a small percentage of the days of the year. The greater likelihood
is that
[[Page 50508]]
not every individual is taken, or perhaps a smaller subset is taken
with a slightly higher average and larger variability of highs and
lows, but still with no reason to think that, for most species or
stocks, any individuals would be taken a significant portion of the
days of the year.
Of note, the Commission identified an error related to potential
impacts to goose-beaked whales (Western North Atlantic stock) in the
Preliminary Assessment and Negligible Impact Determination section of
the proposed rule. This final rule includes a correction to that
language to indicate that the impacts to the Western North Atlantic
stock of goose-beaked whales could cause a limited number of females to
forego reproduction for a year.
Comment 4: The Commission recommended that NMFS work with the Navy
to use its Range-Dependent Acoustic Model and the Navy's Standard
Parabolic Equation (RAM/PE) model for non-impulsive sources to model
all underwater detonations (i.e., impulsive sources) for Phase IV
activities for which modeling has not been completed and for all Phase
V activities, until such time that Comprehensive Acoustic Simulation
System/Gaussian Ray Bundle (CASS/GRAB) and the similitude equation have
been validated for the range of detonation sizes and environmental
parameters (i.e., water depth and receiver range) in which it would be
used. They supported this recommendation by stating that, given the
comparability of the modeled zones from the Peregrine version of RAM/PE
to the measured values and that RAM/PE is already used by the Navy for
modeling non-impulsive sources that operate at less than 100 Hertz (Hz)
and in shallow water, the Navy has the data to conduct a rigorous
comparison of CASS/GRAB and the similitude equation and the in situ
measurements of the USS Ford ship shock trial from Seger et al. (2023)
to fulfill the project's intent and to inform future rulemakings.
Response: Navy has indicated that it plans to conduct a
verification of the impulsive propagation methods in NAEMO using the
Seger et al. (2023) data, which was published by Madhusudhana et al.
(2024).
The NAEMO impulsive modeling methods, as described in the Acoustic
Impacts Technical Report, require arrival times, sound levels, and
phases to be output from the propagation model. RAM/PE does not output
the time information necessary for simulation and is thus not a
suitable option for impulsive modeling in NAEMO. The limitations of the
similitude equation are discussed in section 4.1.3.2 of the Acoustic
Impacts Technical Report and comparisons between the peak pressure
computed at various ranges against the theoretical value based on the
similitude equation showed agreement, providing confidence that the
similitude equation was appropriate for use in NAEMO.
The Navy states that it is committed to ensuring the accuracy of
its impulsive propagation models and recognizes the importance of
ongoing validation efforts. While the similitude equation has been
evaluated and demonstrated good agreement with measured data, as
detailed in section 4.1.3.2 of the Acoustic Impacts Technical Report,
the Navy is open to exploring alternative approaches to meet NAEMO's
requirements.
Comment 5: The Commission highlighted multiple points regarding the
behavioral response functions (BRF) following its review of the
technical report ``Criteria and Thresholds for U.S. Navy Acoustic and
Explosive Effects Analysis (Phase 4)'' (U.S. Department of the Navy,
2024a), which was revised to include updates to the version published
in September 2024 and is hereafter referred to as the revised Criteria
and Thresholds Technical Report (U.S. Department of the Navy, 2025).
These points generally relate to the upper bound of the BRFs, Southall
et al. data, odontocete BRFs, sensitive species BRFs, harbor porpoise
data, pinniped BRFs, response severity denotation, and inconsistencies
in some tables and figures. Please see the Commission's letter for a
detailed discussion of its recommendation.
The Commission recommended that NMFS require the Navy to revise
their criteria and thresholds to clarify and address these points, as
that document underpins the current and future Phase IV rulemakings.
The Commission also states that to increase efficiency for all of the
agencies involved and to ensure accurate information is being provided
for public comment, the Commission would welcome the opportunity to
informally review future versions of the Navy's criteria and threshold
documents. The Commission further recommends that NMFS work with the
Navy to use the dose-response functions that were developed from all of
the raw data rather than those that were regenerated for only moderate
and severe responses and to refrain from extrapolating beyond the
bounds of the underlying data when revising the BRFs.
In a related comment, a commenter stated that NMFS has not
incorporated recent behavioral response data on common dolphins
(Southall et al., 2024), and other important studies highlighted by the
Commission, into its biphasic risk functions. The commenter references
a fuller description of its concern in a comment on the 2024 Hawaii-
California Training and Testing (HCTT) Draft EIS/OEIS.
Response: Regarding the upper bound of the BRFs, the Navy adjusted
the upper bound of the BRFs in Phase IV to more accurately reflect
observed behavioral data, particularly at higher received levels. For
example, sonar received levels between 170 and 182 dB re 1 [micro]Pa
for humpback whales during 3S2 study (the second phase of the Sea
Mammals, Sonar, Safety (3S) project) and between 175 and 186 dB re 1
[micro]Pa for sperm whales during 3S3 study (the third phase of the 3S
project) did not elicit observable responses. See section 3.1.6.1.2 of
the Criteria and Thresholds Technical Report for discussion of the 3S
and 3S2 study, and section and 3.1.6.1.3 for discussion of the 3S3
study. Please see table E-1 in the revised Criteria and Thresholds
Technical Report for details of all individual responses documented
during studies in conjunction with received levels of sonar and sonar
like sources.
Extending the upper bound to 200 dB re 1 [micro]Pa allows the BRFs
to account for this lack of response at higher received levels. This
adjustment does not arbitrarily shift the entire curve to the right, as
the Commission suggests. For groups like pinnipeds, where responses are
consistently observed at lower received levels, the BRF approaches 100
percent response probability at 185 dB re 1 [micro]Pa. Therefore, the
upper bound adjustment primarily impacts the odontocete and mysticete
BRFs, reflecting the observed data at higher exposures. It is also
important to note that the lower bound of the BRFs were extended to 90
dB re 1 [micro]Pa in Phase IV (compared to the 100 dB re 1 [micro]Pa
lower limit used in Phase III), further demonstrating that the
adjustments were not solely focused on increasing the upper bound.
The Commission's observation of a flat slope between 185 and 200 dB
re 1 [micro]Pa for the Phase III BRFs shown in figure 42 (Department of
the Navy, 2024a) was a result of anchoring the Phase III BRFs at 185 dB
re 1 [micro]Pa and then extending them to 200 dB re 1 [micro]Pa for
plotting purposes.
Finally, regarding the point that the upper level of the mysticete
BRF exceeds the TTS onset, it is important to emphasize that auditory
and behavioral criteria are not directly linked. The Navy recognizes
the evolving nature of acoustic science and
[[Page 50509]]
will continue to refine its effects criteria as new data and
understanding become available.
The descriptions of responses in appendix E (Behavioral Responses
to Sonar and Sonar-Like Sources: All Individuals Included) of the
revised Criteria and Thresholds Technical Report have been updated to
include additional information on the observed responses.
Regarding data from Southall et al. (2024), the Navy develops its
BRFs using the best available scientific data. While data from the
Atlantic behavioral response study (BRS) cited by the Commission and
Southall et al. (2024) cited by the commenter were collected during the
timeframe referenced, these data were not available for use in the
development of the BRFs for Phase IV. These functions are always
developed in close consultation with scientists conducting BRS/
controlled exposure experiment (CEE) studies, but when the data are not
yet published, the researchers determine the appropriate time at which
to share data with the Navy. In this case, Atlantic BRS behavioral
response results and Southall et al. (2024) were not shared in time to
be considered and/or included in the development of the Navy risk
thresholds. The Navy did consider data from Southall et al. (2024) in
appendix D of the 2025 AFTT Supplemental EIS/OEIS, indicating the
potential responses observed in this study occurred at received levels
and distances assessed for potentially significant behavioral responses
in the analysis of Phase IV; however, the findings of this study do not
change the conclusions made by the Navy nor NMFS' determination. The
Navy remains committed to incorporating the best available scientific
data into its impact assessments and will revisit its BRFs as new
information, including the published results of the Atlantic BRS,
becomes available.
Regarding the odontocete BRF, all the data from Houser et al.
(2013a, 2013b) were included in the modified risk functions developed
for subsampling in the Navy's BRFs. However, low-severity responses
were classified as ``non-responses'' when deriving the BRFs (see also
Southall et al. (2021) for a description of severity scoring). This
approach, consistent with Phase III, reflects that low-severity
behavioral responses are not typically considered ``harassment'' under
the MMPA during military readiness activities. To balance field and
captive study data, a subsampling method was used. This involved
creating modified risk functions incorporating the new scoring values
(classifying low-severity responses as non-responses) at different
received levels. Thirty data points were then randomly selected from
the bottlenose dolphin risk function generated using this method. This
subsampling approach, similar to that used for beaked whale data in
both Phase III and Phase IV, ensures each individual animal from the
captive study receives equal weight, comparable to individuals from
field studies. This allows for a more comprehensive consideration of
exposures and responses for each species, unlike Phase III's selection
of a single response level per individual. The Navy has clarified this
methodology in the revised Criteria and Thresholds Technical Report.
Further, the Navy's current odontocete BRF considers the potential for
behavioral responses that may qualify as ``harassment'' under the MMPA
for military readiness activities at the estimated received levels in
Southall et al. (2024).
Regarding the sensitive species BRF, while the generalized additive
model (GAM) published in Jacobson et al. (2022) only extended to 165
dB, the Navy requested that authors rerun their model to 200 dB to
create a new curve that could be subsampled for the Navy Phase IV risk
function; the same was done for the Moretti et al. (2014) data.
Therefore, the two beaked whale range-based risk functions extended to
the same bandwidth as the Navy BRF and the subsampling matched the rest
of the data. The Navy has updated the Criteria and Thresholds Technical
Report to reflect that the published GAMs were rerun with the broader
bandwidth. Both Moretti et al. (2014) and Jacobson et al. (2022) were
subsampled 10 times each.
To be included in the BRF, data sets needed to relate known or
estimable received levels to observations of individual or group
behavior. The data in Falcone et al. (2017) is not included in the
development of the BRFs because it is not possible to reasonably
estimate the received levels in this study; however, this data was
considered in developing the distance conditions for the application of
the sensitive species BRF.
The Navy is committed to ensuring scientific integrity in datasets
used for BRF development. Using data that do not meet these criteria
could result in unreliable or misleading risk assessments. A risk
function has not yet been fit to Southern California Anti-Submarine
Warfare Range (SOAR) data for beaked whales, nor has one been fit for
minke whales at PMRF. The BRFs in Phase IV utilized only individual
response-received level data outside of the four pre-existing risk
functions that were subsampled. There were no individual response-
received level data available for beaked whales at SOAR nor for minke
whales at PMRF, therefore those data were not used in the Phase IV
BRFs. As science continues to evolve, the Navy will continue to refine
its effects criteria. The Navy remains committed to incorporating new
data and analyses, including those from SOAR and PMRF, as they become
available and meet the rigorous standards required for robust BRF
development.
Regarding the Kastelein harbor porpoise data, when the same
individuals were tested at multiple received levels for the same source
within a single study, only the lowest received level eliciting a
response was included in the data used for BRF development. However, in
some studies, Kastelein tested the same sources using different
parameters, such as an upsweep versus a downsweep signal (e.g.,
Kastelein et al. (2014b), where both low frequency and mid frequency
active sonar signals were tested as both a downsweep and upsweep), or
as a continuous versus pulsed active sonar signal (e.g., Kastelein et
al., 2018). In that case, the response to both signal parameters would
have been used in the BRF as those would be considered different
signals. The citations for the relevant Kastelein studies, previously
provided in tables 19 and 20, have been added to table E-1 in the
revised Criteria and Thresholds Technical Report.
Regarding the pinniped BRFs, the Navy confirms that all data from
the Houser et al. (2013a) California sea lion controlled exposure
experiment were considered in developing the Phase IV BRFs. However, as
with the odontocete BRF, low-severity responses were classified as
``non-responses'' when deriving the BRF. This decision aligns with the
Navy's approach to assessing potential harassment under the MMPA during
military readiness activities, where low-severity responses are not
typically considered indicative of harassment. The original curves
developed by Houser et al. (2013a) were not used because they included
the low-severity responses as responses. The Navy has clarified this
approach in the revised Criteria and Thresholds Technical Report.
Regarding the identified inconsistencies in some data, tables, and
figures, NMFS and the Navy have carefully reviewed those identified in
the Commission's comments and the Navy has made the necessary
corrections to the revised Criteria and
[[Page 50510]]
Thresholds Technical Report. These revisions ensure consistency in the
reported ranges of received levels, distances, and significant
responses across the executive summary, tables, figures, and
accompanying text. Specifically, the Navy updated table E-1 in the
revised Criteria and Thresholds Technical Report to include data for
Blainville's beaked whales from Tyack et al. (2011). The studies by
Moretti et al. (2014) and Jacobson et al. (2022) involved aggregated
and modeled data rather than individual animal responses and were
therefore incorporated into the BRFs through a random subsampling
process, as described in the Criteria and Thresholds Technical Report,
rather than being presented directly in table E-1, which focuses on
individual-level data. The Navy also addressed inconsistencies between
Cur[eacute] et al. (2025) and table E-1 of U.S. Department of the Navy
(2025) identified by the Commission. The Navy updated the closest
points of approach so that the onset closest point of approach is given
for signals that elicited significant responses, while the closest
point of approach of the overall exposure session is given for signals
that did not elicit a significant response. These corrections only
affect the way data was presented in table E-1 and do not change the
BRFs.
Finally, the Navy has confirmed to NMFS that it used the data from
Houser et al. (2013a) and Houser et al. (2013b) to develop the new risk
functions. As noted previously, low-severity responses were scored as
``non-responses'' within these functions to align with the Navy's
approach to assessing potential harassment under the MMPA. These new
risk functions were then subsampled using the same method applied to
the beaked whale range risk functions in both Phase III and Phase IV,
ensuring consistency in the Navy's treatment of such data. This
subsampling approach, described in detail within those reports, ensures
appropriate weighting of individual responses and contributes to the
robustness of the Navy's BRFs.
Regarding the Commissions' offer to informally review future
versions of the criteria and threshold reports, NMFS recommends that
the Commission coordinate directly with the Navy for any potential
early reviews as the Navy is the primary author.
Comment 6: The Commission recommended that NMFS work with the Navy
in a concerted manner to incorporate data that support criteria and
threshold development more often than on a decadal cycle and to revise
NAEMO to implement the relevant criteria and thresholds at a true post-
processing stage so that animat dosimeter data can be re-queried if
thresholds change, rather than needing to remodel the animat-portion of
NAEMO.
Response: The criteria and thresholds are typically updated at the
beginning of each at-sea phase. This is a significant effort that
involves collecting published data, working with marine mammal
researchers to collect and understand emergent data, developing methods
to incorporate the data, writing and publishing the technical report,
and seeking approvals from Navy leadership and NMFS. Nevertheless,
emergent data is continuously assessed against the current criteria and
thresholds to ascertain whether it would create significant changes to
the Navy's analysis. If so, the analysis would be altered to reflect
this emergent data.
The Navy is continuously reassessing and evolving its analysis
methods including the need to more frequently update criteria and
threshold and the feasibility for NAEMO to more rapidly incorporate
such changes. For example, the Navy has undertaken efforts to
investigate the feasibility of moving the weighting functions to the
post-processor for impulsive modeling, which would allow added
flexibility to the modeling process when new data emerges outside of
the normal criteria and threshold timeline. NMFS supports such efforts.
Comment 7: The Commission recommended that NMFS determine whether
inclusion of data from Kastelein et al. (2024a, 2025a, 2025b) would
alter the weighting functions and/or thresholds for the functional
hearing groups and, if so, whether those modifications would be
sufficient to warrant revision of the weighting functions and
associated thresholds for non-impulsive sources as stipulated in their
criteria and thresholds.
Response: Whether and when to share data for ongoing research is at
the discretion of the researchers and funding agencies. Because the
specific data from Kastelein et al. (2024) were not shared with the
Navy prior to peer review and publication, these data could not be
incorporated into the development of the Phase IV Criteria and
Thresholds. However, the Navy's current approach using the existing
Phase IV criteria remains protective even when compared to the findings
of Kastelein et al. (2024a). Specifically, incorporating the TTS onset
value of 169 dB sound exposure level (SEL) reported by Kastelein et al.
(2024a) would raise the very high frequency (VHF) non-impulse exposure
function by 4 dB. The impact on other impulsive and non-impulsive
exposure functions is negligible (1 dB or less).
NMFS has also reviewed the data from Kastelein et al. (2024b,
2025a, 2025b). Kastelein et al. (2025a) evaluated the effect of one-
sixth octave band noise centered at 40 kilohertz (kHz) on TTS in two
California sea lions (Zalophus californianus). Results indicate that
TTS onset (6 dB threshold shift) occurred at approximately 169 dB
cumulative SEL, which is lower than predicted by the current Phase IV
TTS threshold and weighting function. Interestingly, this TTS onset
level is lower than what was measured during exposure to 32 kHz in a
previous study (179 dB cumulative SEL; Kastelein et al. (2024b)). So,
despite hearing sensitivity decreasing at higher frequencies, Kastelein
et al. (2025a) indicate that TTS onset occurs at a lower level than
predicted, which contradicts typical trends in TTS onset previously
measured in marine mammals. Thus, these data suggest a need to evaluate
exposures at potentially higher frequencies to examine whether this
disparate trend continues.
Kastelein et al. (2025b) examined TTS in two harbor seals (Phoca
vitulina) exposed to one-sixth octave band noise centered at 8 kHz. In
this study, TTS onset (6 dB threshold shift) occurred at approximately
181 dB cumulative SEL, which is higher than what is predicted with the
current Navy Phase IV criteria.
In consideration of the information discussed above, NMFS and Navy
have concluded that revisions to the Phase IV Criteria and Thresholds
are not warranted at this time.
Comment 8: The Commission recommended that NMFS determine whether
the low-frequency (LF) cetacean weighting function has been shifted far
enough to the higher frequencies to reflect that 32 kHz was the most
sensitive frequency tested in minke whales, determine whether use of
the phocid carnivore in water (PCW) composite audiogram, weighting
function, and threshold parameters are more representative of very low-
frequency (VLF) and LF cetaceans than medians and means of the five
other functional hearing groups, and work with the Navy to revise the
VLF and LF cetacean composite audiograms, weighting functions, and
thresholds as needed for impulsive and non-impulsive sources for the
final rule and 2025 AFTT Supplemental EIS/OEIS.
In a related comment, a commenter stated that NMFS has applied a
patently unrealistic, non-conservative auditory weighting scheme for
``low frequency cetaceans'' and references a similar
[[Page 50511]]
comment on the 2024 HCTT Draft EIS/OEIS.
Response: The lack of data on mysticete hearing, especially in
terms of the impacts of noise on hearing, has made this a challenging
group for which to develop acoustic criteria. The Navy has split the
mysticetes into two hearing groups for its Phase IV analyses: VLF and
LF cetaceans (see appendix B of the Criteria and Thresholds Technical
Report). This decision is outlined in detail within the documentation
and includes the best available science including the recommendations
of Southall et al. (2019a) and the minke whale study by Houser et al.
(2024). The Navy was given access to pre-published data on the 2023/
2024 minke whale field season and was able to incorporate into their
Phase IV criteria (noting, as the commenter did that the 2023 field
season data was published in November 2024). In their Phase IV
criteria, the Navy separated VLF cetaceans (i.e., blue, fin, right, and
bowhead whales) from LF cetaceans (all other mysticetes). Thus, they
are acknowledging differences among mysticetes species.
NMFS and the Navy disagree that wholesale adoption of the PCW
parameters or shifting the LF weighting function solely based on the 32
kHz sensitivity of minke whales is scientifically justified. There is
no scientific evidence to support the exclusive use of the PCW
composite audiogram and weighting function parameters for the LF and
VLF groups. Adolescent minke whales were tested by Houser et al. (2024)
specifically because of their small size compared to other baleen
whales. Smaller head size generally facilitates hearing at higher
frequencies, so a shift of the entire LF curve (intended to represent
all species within the hearing group) to a center frequency of 32 kHz
is not likely representative of most baleen whales, which are larger in
size compared to adolescent minke whales.
Therefore, the Navy maintains, and NMFS concurs, that, based on the
weight of the evidence, the existing LF weighting function and the use
of medians and means from multiple functional hearing groups provide a
more representative and protective approach for assessing acoustic
impacts on VLF and LF cetaceans. This approach incorporates data from a
broader range of species and avoids overreliance on data from a single
species or functional hearing group. NMFS' approach has remained
consistent throughout our technical guidance development (2016, 2018,
2024), and we have addressed comments on the LF cetacean weighting
function in our previous Federal Register notices finalizing these
documents (81 FR 51693, August 4, 2016; 89 FR 84872, October 24, 2024).
NMFS' 2024 Technical Acoustic Guidance does not incorporate the recent
data on minke whale hearing. However, NMFS has committed to
incorporating this data into future versions, as indicated in our 2024
Updated Technical Guidance. NMFS is awaiting the publication from the
2024 field season to be published and made publicly available before
re-evaluating our acoustic criteria for mysticetes.
Comment 9: A commenter stated that NMFS has relied improperly on
means and medians in establishing its thresholds for auditory impacts
and references a similar comment on the 2024 HCTT Draft EIS/OEIS. In
that comment, the commenter recommends implementation of a 6 dB
reduction to its TTS and PTS thresholds in line with the suggestions by
Tougaard et al. (2015). The commenter states that a 6 dB adjustment
would accord with the minimum level of ``non-trivial'' TTS required to
evaluate onset, effectively adjusting the exposure functions to more
closely match the point where TTS begins.
Response: The technical guidance appropriately uses measures of
central tendency based on an onset level of 6 dB TTS. No reduction is
necessary or supported by the scientific literature, especially
considering numerous other conservative methods in the auditory
criteria. For example, the Navy, and subsequently NMFS, assumes no
recovery of hearing during time intervals between intermittent
exposures. However, multiple studies from humans, terrestrial mammals,
and marine mammals have demonstrated less TTS from intermittent
exposures compared to continuous exposures with the same total energy
because hearing is known to experience some recovery in between noise
exposures. Therefore, the Navy's approach, as relied upon in NMFS'
proposed and final rules, is known to overestimate the effects of
intermittent noise sources such as tactical sonars. Further, marine
mammal TTS data have shown that, for two exposures with equal energy,
the longer duration exposure tends to produce a larger amount of TTS.
Since most marine mammal TTS data have been obtained using exposure
durations up to an hour, much longer than the durations of many
tactical sources, the use of the existing marine mammal TTS data tends
to over-estimate the effects of sonars with shorter duration signals.
Comment 10: A commenter stated that NMFS wholly discounted gas-
bubble pathology as a mechanism of harm to marine mammals due to the
specified activities, and that the Action Proponents must assume that a
number of beaked whales are subject to injury and mortality from gas-
bubble formation.
Response: The commenter's characterization of NMFS' analysis is
incorrect. NMFS does not disregard the fact that it is possible for
naval activities using hull-mounted tactical sonar to contribute to the
death of marine mammals in certain circumstances (that are not present
in the AFTT Study Area) via strandings resulting from behaviorally
mediated physiological impacts or other gas-related injuries. In the
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat section of the proposed rule, NMFS discusses these potential
causes and outlines the few cases where active naval sonar (in the U.S.
or, largely, elsewhere) has either potentially contributed to or, as
with the Bahamas example, been more definitively causally linked with
marine mammal strandings. As noted, there are a suite of factors that
have been associated with these specific cases of strandings directly
associated with sonar (steep bathymetry, multiple hull-mounted
platforms using sonar simultaneously, constricted channels, strong
surface ducts, etc.). These factors are not present together in the
AFTT Study Area during the specified activities (and the Navy takes
care across the world not to operate under these circumstances without
additional monitoring). Further, there have never been any strandings
associated with Navy sonar use in the AFTT Study Area. For these
reasons, NMFS does not anticipate that the Action Proponents' training
or testing activities will result in marine mammal strandings, and none
are authorized. Furthermore, ongoing Navy funded beaked whale
monitoring at a heavily used training and testing area in the SOCAL
Range Complex has not documented mortality or habitat abandonment by
beaked whales. Passive acoustic detections of beaked whales have not
significantly changed over 10 years of monitoring (DiMarzio et al.,
2018; DiMarzio et al., 2019; DiMarzio et al., 2020). From visual
surveys in the area since 2006 there have been repeated sightings of
the same individual beaked whales, beaked whale mother-calf pairs, and
beaked whale mother-calf pairs with mothers on their second calf
(Schorr et al., 2018; Schorr et al., 2020). Satellite tracking studies
of beaked whales documented high site fidelity to this area even though
the
[[Page 50512]]
study area is located in one of the most used Navy areas in the Pacific
(Schorr et al., 2018; Schorr et al., 2020).
Comment 11: A commenter stated that NMFS failed to present a
meaningful analysis of the Navy's aggregate effects on marine mammal
populations and refers to its comment on the 2024 HCTT Draft EIS/OEIS.
Response: The commenter's supporting rationale for their comment is
in reference to the 2024 HCTT Draft EIS/OEIS. While some of the
information considered in the AFTT proposed rule and this final rule is
generally similar, the commenter has not provided recommendations
specific to how NMFS' analysis of the Action Proponents activities in
the proposed rule fails to consider the Action Proponents' aggregate
effects on marine mammal populations. NMFS fully analyzed and
considered the potential for aggregate effects from all of the Action
Proponents' specified activities, and has applied a reasoned and
comprehensive approach to evaluating the effects of these activities on
marine mammal species or stocks and their habitat. This analysis was
detailed in the Preliminary Analysis and Negligible Impact
Determination section of the proposed rule and is repeated here in the
Analysis and Negligible Impact Determination section of the final rule.
Our analysis includes consideration of unusual mortality events
(UMEs) and previous environmental impacts, where appropriate, to inform
the baseline levels of both individual health and susceptibility to
additional stressors, as well as stock status. Further, the species and
stock-specific assessments in the Analysis and Negligible Impact
Determination section (which have been updated and expanded since the
previous AFTT rulemaking to consider additional species- and stock-
specific factors) present and address the combined mortality, injury,
behavioral harassment, and other effects of the aggregate activities,
including impacts anticipated in important habitats such as Endangered
Species Act (ESA)-designated critical habitat and known BIAs (and in
consideration of applicable mitigation), as well as other information
that supports our determinations that the Action Proponents' activities
will not adversely affect any species or stocks via impacts on annual
rates of recruitment or survival. We refer the reader to the Analysis
and Negligible Impact Determination section for this analysis.
Further, widespread, extensive monitoring since 2006 on Navy ranges
that have been used for training and testing for decades has
demonstrated no evidence of population-level impacts (see https://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/
for results, e.g., ``Cuvier's Beaked Whale and Fin Whale Population
Dynamics and Impact Assessment at the Southern California Offshore
Antisubmarine Warfare Range (SOAR)''). Based on the best available
research from NMFS and Navy-funded marine mammal studies, there is no
evidence that ``population-level harm'' to marine mammals, including
beaked whales, is occurring in the AFTT Study Area.
Comment 12: The Commission recommended that NMFS work with the Navy
to reprogram NAEMO to implement densities at a post-processing stage so
that densities can be easily revised rather than needing to remodel the
animat-portion of NAEMO when density estimates change. The Commission
states that such an improvement was recommended by Simmons et al.
(2025) to be addressed through modifications to animat seeding and
investigating runs by hearing group within NAEMO.
Response: NMFS concurs that it is appropriate to explore whether
NAEMO can be reprogrammed to implement densities at a post-processing
stage so that densities can be easily revised rather than needing to
remodel the animat-portion of NAEMO when density estimates change. The
Navy has undertaken work in Fiscal Year 2025 to explore standardization
of animat distributions and statistical considerations of applying
species' densities after the NAEMO post-processor to scale results. If
the Navy, in coordination with NMFS, finds that this proves feasible
and appropriate, the Navy hopes to implement this for Phase V.
Comment 13: The Commission recommended that NMFS refrain from using
cut-off distances in conjunction with the Bayesian BRFs and re-estimate
the numbers of marine mammal takes based solely on the Bayesian BRFs
for the final rule.
In a related comment, a commenter stated that NMFS reduces the
Navy's modeled take estimates through the application of cut-off
distances that do not make sense conceptually, that are based on little
or no data from the behavioral response literature, and that contradict
data that are available, including Falcone et al. (2017) and
Melc[oacute]n et al. (2012). The commenter refers to a description of
their concern in a comment on the 2024 HCTT Draft EIS/OEIS, in which
they state that they agree with the Commission's recommendation that
the Navy refrain from using cut-off distances and rely instead on the
take estimates produced through its response functions.
Response: The consideration of proximity (cut-off distances) was
part of the criteria developed in consultation between the Navy and
NMFS, and is appropriate based on the best available science, which
shows that marine mammal responses to sound vary based on both sound
level and distance. Therefore, these cut-off distances were applied
within NAEMO. The derivation of the BRFs and associated cut-off
distances is provided in the revised Criteria and Thresholds Technical
Report.
The Phase IV approach represents a refinement in assessing
potential behavioral impacts. It employs a probability of response
condition for high source level exposures, addressing previous concerns
from the Commission about potentially cutting off responses when the
probability remained above 50 percent. This approach, combined with the
distance cut-off, provides a more nuanced and protective assessment
compared to the Phase III methodology, which relied solely on distance
cut-offs. Therefore, directly comparing Phase III and Phase IV cut-off
distances is not appropriate.
NMFS and the Navy are confident that this combined distance and
probability threshold approach is well-substantiated by available data
and effectively avoids underestimating potential behavioral responses
to acoustic sources.
To clarify, section 3.1.4 (Dose and Contextual Responses) of the
Criteria and Thresholds Technical Report explains that at low received
levels, distance to the sound source factors into the likelihood of a
behavioral response. Although distance was investigated as a covariate
in the Bayesian BRF model, most BRFs to date have used similar source
levels making received level and source-receiver distance tightly
correlated (see section 3.1.9 (Behavioral Cut-off Conditions) of the
Criteria and Thresholds Technical Report). Therefore, including
distance in the BRF model using the available response-received level
data did not improve the BRFs. Still, NMFS and the Navy agree that
distance is an important contextual factor. Since it was not possible
to directly account for distance in the Bayesian model at this time,
the Navy incorporated the behavioral cut-off conditions, beyond which
significant behavioral reactions are assumed to be unlikely. As
described in section 3.1.9 of the Criteria and Thresholds Technical
Report, the distance cut-off conditions were conservatively estimated
based on
[[Page 50513]]
observations from multiple cited studies. Applying the distance cut-off
condition is appropriate to reasonably estimate significant impacts.
In addition, high source level exposures are addressed by also
using a probability of response condition rather than the dual distance
cut-off applied in Phase III. This method was devised in part to
address public comments, including those from the Commission received
in Phase III that were focused on cutting off behavioral responses, in
some cases, where the probability of response was still above 50
percent. The probability of response cut-off condition in Phase IV
allows for prediction of significant impacts beyond the distance cut-
off.
Regarding the studies cited by a commenter, Melc[oacute]n et al.
(2012) found that the probability of recording blue whale ``D calls''
decreased with higher received levels at the high-frequency acoustic
recording package (HARP) buoy averaged over many hours; however, this
study does not provide any information about the distance between the
sound source and any animals and cannot be used to derive cut-off
distances. Falcone et al. (2017) was reviewed by the Navy and discussed
in the Criteria and Threshold Technical Report: ``. . . Falcone et al.
(2017) modeled apparent responses to mid-powered sources out to 50 km
(27 nmi) and responses to high-powered sources at distances as great as
100 km (54 nmi). However, the models were not developed to estimate
distances to response, and care needs to be taken when interpreting the
results in that context.'' Responses at 100 km (54 nmi) were generally
mild, such as a slight (i.e., less than 2 minute) increase in the
duration of shallow dives that was similar to the range of duration
variability found in dives when no mid-frequency active sonar was
present. The inter-deep dive interval duration also increased for both
mid- and high-powered mid-frequency active sonar (MFAS) sources
starting at 100 km (54 nmi); however, the inter-deep dive interval
duration exhibited the strongest increase only within 20 km (10.8 nmi)
of the source.
As described in section 3.1.9 of the Criteria and Thresholds
Technical Report, the cut-off conditions are applied to predict
significant behavioral responses. The data used to inform the BRFs
includes observations beyond 10 km (5.4 nmi) and studies cited in
section 3.1.9 of the Criteria and Thresholds Technical Report. This
includes data on exposures to other sound sources which is informative
when data on exposure to sonars is limited. All the identified
significant behavioral responses that were used to develop the BRFs are
within the cut-offs (either by distance or sound pressure level (SPL)).
Although behavioral responses are predicted beyond the cut-off
conditions, these are not expected to qualify as harassment under the
MMPA as defined for military readiness activities.
NMFS and the Navy acknowledge the Commission's perspective but
maintain that the combined use of cut-off distances and BRFs provides a
more accurate and realistic assessment of potential behavioral impacts,
particularly for military readiness activities. While Tyack and Thomas
(2019) cautioned against using step functions anchored to the 50
percent response level of dose-response curves, the Navy's methodology
does not employ such an approach. Instead, the cut-off distances,
informed by the farthest observed distances of significant behavioral
reactions in the available data (including those exceeding 10 km (5.4
nmi)), serve as a threshold for identifying responses reasonably likely
to qualify as harassment under the MMPA. This approach prevents
underestimating significant impacts while acknowledging that responses
occurring beyond these distances, while possible, are less likely to
reach this level of concern.
The Navy's Phase IV approach, incorporating both BRFs and
scientifically informed cut-off distances, offers a more realistic
assessment of potential behavioral impacts compared to relying solely
on BRFs. This approach balances the statistical probabilities derived
from the BRFs with empirical observations of behavioral responses in
the field. NMFS and the Navy are confident that this combined approach,
while still incorporating conservatism to account for uncertainty, does
not underestimate potential take by Level B harassment under the MMPA
during military readiness activities and provides a more accurate
representation of potential impacts.
NMFS has independently assessed the thresholds used by the Navy to
identify Level B harassment by behavioral disturbance and finds that
they appropriately apply the best available science and it is not
necessary to recalculate take estimates. As the science related to
marine mammal behavior advances, NMFS and the Navy will continue to
refine consideration of contextual factors, such as distance, in its
assessment of behavioral responses.
Comment 14: The Commission continues to maintain that NMFS has not
provided adequate justification for dismissing the possibility that
single underwater detonations can cause a behavioral response, and,
therefore, again recommended that it estimate and authorize takes by
Level B harassment of marine mammals during all explosive activities,
including those that involve single detonations and gunnery exercises
that have several detonations occurring within a few seconds. The
Commission further recommends that NMFS encourage the Navy to invest
resources in conducting BRSs on marine mammals' responses, including
pinniped responses, to underwater detonations for the derivation of
explosive BRFs, or at the very least a source-specific step-function
threshold, noting that the Navy's Living Marine Resources program has
provided funding for a few opportunistic studies involving behavioral
response of cetaceans exposed to underwater detonations.
Response: NMFS acknowledges the possibility that single underwater
detonations (including some multiple explosive events, such as certain
naval gunnery exercises, that may be treated as a single event because
a few explosions occur closely spaced within a very short time (a few
seconds)) can cause a behavioral response. The current take estimate
framework allows for the consideration of animals exhibiting behavioral
disturbance during single explosions as they are counted as ``taken by
Level B harassment'' if they are exposed above the TTS threshold, which
is 5 dB higher than the behavioral harassment threshold for multiple
detonations. We acknowledge in our analysis that individuals exposed
above the TTS threshold may also be harassed by behavioral disruption
and those potential impacts are considered in the Analysis and
Negligible Impact Determination section. Neither NMFS nor the Navy are
aware of evidence to support the assertion that animals will have
multiple significant behavioral responses (i.e., those that would
qualify as take) to temporally and spatially isolated explosions at
received levels below the TTS threshold. However, if any such responses
were to occur, they would be expected to be rare and since separated in
space and time, would most likely result only in isolated startle
responses (i.e., additional behavioral responses would not be expected
to add cumulatively or in severity). Furthermore, these rare responses
would not be expected to occur at received levels below TTS onset.
Thus, they would occur at received levels already bounded by the single
[[Page 50514]]
detonation criteria (i.e., TTS is used as the Level B harassment
criteria for single detonations) and would therefore already be
accounted for in the current take estimates.
The derivation of the explosive injury criteria is provided in the
Criteria and Thresholds Technical Report. There is limited information
upon which to estimate behavioral response thresholds specific to
explosives. Therefore, as described in the Criteria and Thresholds
Technical Report, the behaviors exhibited by animals exposed to brief
intense tones in the Schlundt et al. (2000) study continue to inform
the behavioral response threshold for explosives. Some of the observed
behaviors in that study would be considered moderate severity for
captive animals with trained behaviors and thus may be potentially
significant in the context of wild animals. Appropriate threshold
metrics are applied for this criterion given the supporting data.
Additionally, RMS SPLs are not a preferred metric for explosives due to
the challenge of identifying the appropriate time window.
Most explosive activities, including all explosive gunnery
activities, analyzed in the rule and the 2025 AFTT SEIS/OEIS include
multiple detonations. For these activities, significant behavioral
responses are assumed to occur if the cumulative SELs are greater than
or equal to 5 dB less than the threshold for onset of TTS. For single
detonations, the analysis in appendix E of the 2025 AFTT Supplemental
EIS/OEIS assumes that any auditory impact (TTS or AUD INJ) may have a
concurrent significant behavioral response. This assumption for single
detonations has been clarified in the revised Criteria and Thresholds
Technical Report.
BRSs on marine mammal responses to underwater detonations would
support future analyses, and NMFS will consider such a recommendation
to Navy relative to other new and ongoing research priorities. The Navy
supports a wide range of research to inform the development of
criteria. The Navy is supporting new research into marine mammal
behavioral responses to detonations through its Living Marine Resources
program (https://exwc.navfac.navy.mil/Products-and-Services/Environmental-Security/LMR/). The findings of this research will be
incorporated into the behavioral response criteria when available. To
clarify, the Navy has specifically monitored shock trial detonations
since the 1990s. Madhusudhana et al. (2024) present data on pre- and
post-detonation vocalizations at monitoring sites in the vicinity of
the 2021 full ship shock trial. Most sites showed no significant
changes in vocalization activity for the timeframes analyzed.
Mitigation and Monitoring
Comment 15: The Commission strongly recommended that NMFS require
the Navy to use passive acoustic monitoring (PAM) prior to and during
activities involving ship shock trials in the final rule, consistent
with explosive sonobuoys, explosive torpedoes, and sinking exercises.
The Commission notes that since mission effectiveness would not be
impacted, the measures are considered practicable, and their
implementation would reduce the potential for the most lethal marine
mammal impacts.
Response: As detailed in table 38, the time and location of ship
shock trials are chosen specifically to avoid impacts to large whales
and, further, Naval Sea Systems Command (NAVSEA) will develop an
extensive mitigation plan for NMFS review and concurrence prior to a
ship shock trial. While use of sonobuoys would not affect the ship
shock trial, PAM from a 2001 ship shock trial for the Churchill full
ship shock trial indicated limited efficacy of the PAM (Clarke and
Norman, 2005). As such, and given the significant expense associated
with implementing PAM for ship shock trials, NMFS is not requiring the
Navy to conduct PAM prior to and during ship shock trials.
Comment 16: The Commission strongly recommended that NMFS require
the Navy to use passive acoustic devices (i.e., directional frequency
analysis and recording (DIFAR) and other types of passive sonobuoys,
operational hydrophones) prior to explosive bombing exercises and air-
to-surface and surface-to-surface explosive missile and rocket
exercises to detect marine mammals and implement the necessary
mitigation measures in the final rule.
Response: The Navy employs PAM to supplement visual monitoring when
practicable to do so (i.e., when assets that have PAM capabilities are
already participating in the activity). For explosive events in which
there are no platforms participating that have PAM capabilities, adding
PAM capability for mitigation, either by adding a PAM device (e.g.,
hydrophone) to a platform already participating in the activity or by
adding a platform with integrated PAM capabilities to the activity
(e.g., a sonobuoy), is not practicable.
The type of aircraft that conduct these bombing, missile, and
rocket exercises do not have the capability to deploy and employ
sonobuoys. The Action Proponents state that diverting platforms that
have PAM capabilities would impact their ability to meet their Title 10
requirements and reduce the service life of those systems. The Action
Proponents additionally state that there are significant manpower and
logistical constraints that make constructing and maintaining
additional PAM systems or platforms for additional training and testing
activities impracticable. Given the impracticality of such a measure,
NMFS has found that this measure is not warranted, and it is not
required in this final rule.
Comment 17: The Commission recommended that NMFS prohibit
detonation of explosive sonobuoys within 3 nmi (5.6 km) of the
Southeast North Atlantic Right Whale Mitigation Area from 15 November
through 15 April and the Rice's Whale Mitigation Area year-round in the
final rule consistent with the Northeast North Atlantic Right Whale
Mitigation Area.
Response: NMFS concurs with the Commission's recommendation, and
the Action Proponents have indicated that such a measure is
practicable. Therefore, this final rule includes requirements that
prohibit detonation of explosive sonobuoys within 3 nmi (5.6 km) of the
Southeast North Atlantic Right Whale Mitigation Area from 15 November
through 15 April and in the Rice's Whale Mitigation Area year-round.
Comment 18: The Commission recommended that NMFS require the Navy
to use its instrumented ranges and sonobuoys to localize marine mammals
and implement the relevant mitigation measures during active acoustic
events and to take a harder look at the technologies that the Canadian
Department of National Defense (DND) uses during its at-sea activities
and incorporate those technologies accordingly for other Phase IV LOA
applications. The Commission cites the Lookout Effectiveness Study
(Oedekoven and Thomas, 2022) in support of its recommendation. In a
related comment, a commenter stated that to maximize the probability of
detecting one or more North Atlantic right whales (NARWs) and further
reduce risk to the species, the Action Proponents should use both
visual observations and passive acoustic detections to inform
mitigation decisions and raise the awareness of Lookouts.
Response: The Action Proponents intend to continue to use PAM prior
to activities involving explosive sonobuoys and explosive torpedoes,
and during sinking exercises (SINKEX). During the use of active
acoustics, Navy assets with
[[Page 50515]]
PAM capabilities (e.g., sonobuoys) that are already participating in an
activity will continue to monitor for marine mammals, as described in
section 5.6 (Activity-based Mitigations) of the 2025 AFTT Supplemental
EIS/OEIS. However, the fluidity and nature of military readiness
activities (e.g., fast-paced and mobile readiness evolutions), as well
as the limitations of these monitoring capabilities, make it
impractical for passive acoustic devices to be used as precise real-
time indicators of marine mammal location for mitigation (e.g., active
sonar power downs or shutdowns, ceasing use of explosives) without an
accompanying visual sighting. While we acknowledge that the Lookout
Effectiveness Study suggests that detection of marine mammals is less
certain than previously assumed at certain distances, we disagree with
the assertion that the use of Lookouts has been shown to be wholly
ineffective. Lookouts remain an important component of the Action
Proponents' mitigation strategy, especially as it relates to minimizing
exposure to the more harmful impacts that may occur within closer
proximity to the source, where Lookouts are most effective. Further,
this final rule requires that in the Northeast North Atlantic Right
Whale Mitigation Area and the Dynamic North Atlantic Right Whale
Mitigation Area, the Action Proponents must provide the WhaleMap web
address (https://whalemap.org) and advise that risk of whale strike is
increased: (1) after observing a NARW; (2) when operating within 5 nmi
(9.3 km) of a known sighting reported within the past 24 hours; (3)
within a NMFS-designated Seasonal Management Area, Dynamic Management
Area, or Slow Zone; and (4) when transiting at night or during periods
of reduced visibility. This final rule also requires that sightings
data must be used when planning propulsion testing event details (e.g.,
timing, location, duration) in the Dynamic North Atlantic Right Whale
Mitigation Area to minimize impacts to NARW to the maximum extent
practical, and during propulsion testing, to the maximum extent
practical, Lookouts must be provided recent WhaleMap (https://whalemap.org/) sightings data to help inform visual observations. Last,
in the Northeast North Atlantic Right Whale Mitigation Area, the Action
Proponents must conduct a web query or email inquiry to the North
Atlantic Right Whale Sighting Advisory System or WhaleMap (https://whalemap.org/) to obtain the latest NARW sightings data prior to
transiting the mitigation area. The Action Proponents must provide the
sightings data to Lookouts prior to them standing watch. Lookouts must
use that data to help inform visual observations during vessel
transits.
In the AFTT Study Area, a small subset of Navy training and testing
takes place on the only instrumented range within the study area. The
Navy's instrumented ranges do not have the capabilities to be used
effectively for mitigation (see section 5.5.3 (Active and Passive
Acoustic Monitoring Devices) of the 2018 AFTT EIS/OEIS). As such, NMFS
disagrees with the Commission's assertion that real time localization
of marine mammals using the Navy's instrumented ranges and sonobuoys is
an appropriate requirement, beyond what the Action Proponents are
currently doing.
The Action Proponents and NMFS have considered and will continue to
study the Canadian DND project, including the technologies used during
at-sea activities; however, NMFS disagrees that such a requirement is
warranted in this final rule. As more information from the Canadian DND
project becomes available, the Action Proponents and NMFS may
reconsider whether additional requirements are needed.
Comment 19: The Commission recommends that the NMFS final rule
require the Action Proponents to follow established incident reporting
procedures and halt any active acoustic, explosive, pile-driving, or
air gun activity if a marine mammal is injured or killed during or
immediately after the activity and require the Action Proponents to
consult with NMFS to review or adapt the mitigation measures, as
necessary.
Response: The proposed rule and this final rule include a
requirement for the Action Proponents to follow established incident
reporting procedures if the specified activity is thought to have
resulted in the mortality or serious injury of any marine mammals, as
recommended by the Commission as outlined in the Notification and
Reporting Plan. Note that the Notification and Reporting Plan also
requires the Action Proponents to follow established incident reporting
protocols for cetacean live strandings. Regarding the Commission's
recommendation to require that the Action Proponents halt any active
acoustic, explosive, pile driving, or air gun activity if a marine
mammal is injured or killed during or immediately after the activity,
and require the Action Proponents to consult with NMFS to review or
adapt the mitigation measures, as necessary, NMFS agrees with the
recommendation to suspend the use of explosives in an event if a marine
mammal is injured or killed during or immediately after the activity.
Neither NMFS nor the Action Proponents anticipate serious injury or
mortality from any activity other than the use of explosives or vessel
movement. For all activities involving explosives, the final rule
expressly requires that, if a marine mammal is visibly injured or
killed as a result of detonation, use of explosives in the event must
be suspended immediately (see Mitigation Measures section). While
similar language is not included for active acoustics, pile driving,
and air gun activity, the proposed rule and this final rule require the
Action Proponents to power down or shut down these sources if a marine
mammal is observed within the applicable mitigation zone. The Action
Proponents will also continue to follow incident reporting procedures
(including for vessel strike, should it occur) and consult with NMFS to
review or adapt the mitigation measures, as necessary, through the
adaptive management process.
Comment 20: The Commission recommended that NMFS--
Clearly separate its application of the least practicable
adverse impact requirement from its negligible impact determination;
Adopt a clear decision-making framework that recognizes
the species and stock component and the marine mammal habitat component
of the least practicable adverse impact provision and always consider
whether there are potentially adverse impacts on marine mammal habitat
and whether it is practicable to minimize them;
Rework its evaluation criteria for applying the least
practicable adverse impact standard to separate the factors used to
determine whether a potential impact on marine mammals or their habitat
is adverse and whether possible mitigation measures would be effective;
Address these concerns by adopting a simple, two-step
analysis that more closely tracks the statutory provisions being
implemented and, if NMFS is using some other legal standard to
implement the least practicable adverse impact requirements, provide a
clear and concise description of that standard and explain why it
believes it to be ``sufficient'' to meet the statutory legal
requirements; and
Apply these basic steps and criteria consistently for
least practicable adverse impact determinations across incidental take
authorizations.
The Commission references previous letters in which it has included
its
[[Page 50516]]
complete rationale for these recommendations.
Response: NMFS has made clear in this and other rules that the
agency separates its application of the least practicable adverse
impact requirement in the Mitigation Measures section from its
negligible impact analyses and determinations for each species or stock
in the Analysis and Negligible Impact Determination section. Further,
NMFS has made this separation clear in practice for years by requiring
mitigation measures to reduce impacts to marine mammal species and
stocks and their habitat for all projects, even those for which the
anticipated take would clearly have a negligible impact, even in the
absence of mitigation.
In the Mitigation Measures section of this rule, NMFS has explained
in detail our interpretation of the least practicable adverse impact
standard, the rationale for our interpretation, and how we implement
the standard. The method the agency uses addresses all of the necessary
components of the standard and produces effective mitigation measures
that result in the least practicable adverse impact on both the species
or stocks and their habitat. The commenter has failed to illustrate why
NMFS' approach is inadequate or why the commenter's proposed approach
would be better, and we therefore decline to accept the recommendation.
Also in the Mitigation Measures section, NMFS has explained in
detail our application of the least practicable adverse impact
standard. The commenter has recommended an alternate way of
interpreting and implementing the least practicable adverse impact
standard, in which NMFS would consider the effectiveness of a measure
in our evaluation of its practicability. The commenter erroneously
asserts that NMFS currently considers the effectiveness of a measure in
a determination of whether the potential effects of an activity are
adverse, but the commenter has misunderstood NMFS' application of the
standard--rather, NMFS appropriately considers the effectiveness of a
measure in the evaluation of the degree to which a measure will reduce
adverse impacts on marine mammal species or stocks and their habitat,
as a less effective measure will less successfully reduce these impacts
on marine mammals. Further, the commenter has not provided information
that shows that their proposed approach would more successfully
evaluate mitigation under the least practicable adverse impact
standard, and we decline to accept it.
Further, NMFS disagrees with the commenter's assertion that
analysis of the rule's mitigation measures under the least practicable
adverse impact standard remains unclear or that the suggested
shortcomings exist. The commenter provides no rationale as to why the
two-step process they describe is better than the process that NMFS
uses to evaluate the least practicable adverse impact that is described
in the rule, and therefore we decline to accept the recommendation.
Regarding the assertion that the standard shifts on a case-by-case
basis, the commenter misunderstands NMFS' process. Neither the least
practicable adverse impact standard nor NMFS' process for evaluating it
shifts on a case-by-case basis. Rather, as the commenter suggests
should be the case, the evaluation itself is case-specific to the
proposed activity, the predicted impacts, and the mitigation under
consideration.
Regarding the recommendation to apply the recommended steps and
criteria for least practicable adverse impact determinations across
incidental take authorizations, as outlined above, NMFS disagrees with
these recommendations and therefore does not intend to apply them
across incidental take authorizations.
Comment 21: A commenter stated that to adequately protect NARW, the
boundaries of the Southeast North Atlantic Right Whale Mitigation Area,
and its requirements, should be extended north to Cape Fear, North
Carolina. The commenter said this extension would limit the use of
active sonar, prohibit in-water explosives and non-explosive ordnance,
and impose several measures to reduce the risk of vessel strike in the
entirety of the species' calving habitat from November 15 to April 15,
reflecting the duration of the calving season.
Response: Expansion of the Southeast North Atlantic Right Whale
Mitigation Area northward to encompass all areas of potential
occurrence would require training activities to move farther north or
farther out to sea, which the Action Proponents indicate is
impracticable due to implications for safety and sustainability, as
detailed in section 5.4.3 (Mitigation Areas off the Mid-Atlantic and
Southeastern United States) of the 2018 AFTT Final EIS/OEIS.
Additionally, that section explains why further limitations on
activities, including limitations on active sonar, in-water explosives
and non-explosive ordnance, and imposition of additional measures to
reduce the risk of vessel strike, within this area would be
impracticable. NMFS reviewed and concurs with the Action Proponents'
assessment of practicability, effects on mission effectiveness, and
personnel safety, and as such, has not required expansion of the
Southeast North Atlantic Right Whale Mitigation Area beyond that
included in the proposed rule.
The best available density data for the AFTT Study Area shows that
the Southeast North Atlantic Right Whale Mitigation Area encompasses
the areas of highest density in the region (Roberts et al., 2023; U.S.
Department of the Navy, 2025). Although NARW have been sighted on rare
occasions east of the mitigation area, these animals were located
outside of the higher use habitats that represent the primary
occurrence of the population. Overall, most NARW sightings made during
Navy and NMFS surveys have occurred in, or very close to, the Southeast
North Atlantic Right Whale Mitigation Area, which further indicates
that the mitigation area may have the highest seasonal abundance of
NARW in waters off the mid-Atlantic and southeastern United States.
Though the spatial extent of the Southeast North Atlantic Right
Whale Mitigation Area cannot be extended, this final rule includes
additional mitigations in that area and in the Dynamic North Atlantic
Right Whale Mitigation Area, which encompasses the U.S. Exclusive
Economic Zone (EEZ) off the East Coast. In the Southeast North Atlantic
Right Whale Mitigation Area, this final rule includes two new
requirements. First, from November 15 to April 15, the Action
Proponents must not detonate explosive sonobuoys within 3 nmi (5.6 km)
of the Southeast North Atlantic Right Whale Mitigation Area. Second,
during the same time period, the Action Proponents must not conduct
vessel propulsion testing. In the Dynamic North Atlantic Right Whale
Mitigation Area, in Protective Measures Assessment Protocol (PMAP)-
generated reports, Action Proponents will provide the WhaleMap web
address (https://whalemap.org); advise that risk of whale strike is
increased after observing a NARW; when operating within 5 nmi (9.3 km)
of a known sighting reported within the past 24 hours; within a NMFS-
designated Seasonal Management Area, Dynamic Management Area, or Slow
Zone; and when transiting at night or during periods of reduced
visibility; and reinforce the requirement of the International
Regulations for Preventing Collisions at Sea (COLREGS) for vessels to
proceed at a safe speed, appropriate to the prevailing circumstances
and conditions, to avoid a collision with any
[[Page 50517]]
sighted object or disturbance, including any marine mammal.
Additionally, during propulsion testing in the mitigation area, to the
maximum extent practical, Lookouts will be provided recent https://www.whalemap.org sightings data to help inform visual observations.
Further, this final rule requires that within the first year of
AFTT Phase IV implementation, the Action Proponents must work
collaboratively with the NMFS ESA Interagency Cooperation Division and
the NMFS Permits and Conservation Division to: (1) analyze and discuss
the application of new information from the NMFS North Atlantic Right
Whale Persistence Modelling Efforts toward AFTT mitigation measures;
(2) evaluate the practicability and conservation benefits of newly
proposed mitigation measures and/or changes to existing measures based
on information from the model; and (3) implement any new mitigation
measures or changes to existing measures that meet the Action
Proponents' Practicability Criteria and Sufficiently Beneficial
requirements.
Comment 22: The Commission stated that under the Gulf biological
opinion (commonly referred to as BiOp) for oil and gas activities, the
Bureau of Ocean Energy Management (BOEM) and the Bureau of
Environmental Safety and Enforcement (BSEE) would be required to
identify a near real-time platform (e.g., WhaleAlert) to help oil- and
gas-related vessels avoid strikes of Rice's whales. BOEM and BSEE, in
collaboration with NMFS, also must work to ensure additional devices
and near real-time detection data systems are integrated into the near
real-time sightings platform to establish an integrated platform for
all Rice's whale detections in the Gulf (e.g., WhaleMap). The
Commission recommends that NMFS require the Action Proponents to
conduct a query of the aforementioned platform (e.g., WhaleAlert,
WhaleMap) that houses the Rice's whale sightings once it is established
and prior to transiting the Rice's Whale Mitigation Area, provide those
sightings data to the Lookouts prior to them standing watch, use the
data to inform the Lookouts' visual observations during vessel
transits, and implement speed reductions to 10 knots (kn) (18.5 km/hr)
for surface ships transiting within 5 nmi (9.3 km) of a sighting
reported in the platform within the previous 24 hours. Any
modifications to the mitigation requirements for the Rice's Whale
Mitigation Area can be addressed during the Navy's Annual Adaptive
Management Meetings.
In a related comment, a commenter stated that protections must be
afforded to Rice's whale throughout the entirety of their known
habitat, and that NMFS and the Action Proponents should revise the
boundaries of the Rice's Whale Mitigation Area westwards to include all
U.S. waters between the 100-m and 400-m isobaths, to reflect best
available scientific information on the species. The commenter also
recommended that the requirements in the Rice's Whale Mitigation Area
be expanded to include the following mitigation requirements that
emulate a subset of those required for NARW in other proposed
mitigation areas. The commenter stated that the recommendations account
for the fact that an Early Warning System for Rice's whales does not
yet exist. These include:
(1) Year-round within the mitigation area, surface ships must
minimize transits and transit distances through Rice's whale habitat to
the maximum extent practicable, and must implement speed reductions:
(a) after they observe a Rice's whale, if they are within 5 nmi (9.3
km) of a sighting of a Rice's whale reported in the previous 12 hours,
and (b) at minimum, at night and in restricted visibility; and
(2) The Action Proponents must provide Lookouts the sightings data
prior to standing watch to help inform visual observations.
Response: This rulemaking includes a Rice's Whale Mitigation Area
that overlaps the Rice's whale small and resident population area
identified by NMFS in its 2016 status review (Rosel et al., 2016) and
most of the eastern portion of proposed critical habitat (88 FR 47453,
July 24, 2023). Within this area, the Action Proponents must not use
more than 200 hours of surface ship hull-mounted MFAS annually and must
not detonate in-water explosives (including underwater explosives and
explosives deployed against surface targets) except during mine warfare
activities. Additionally, the Ship Shock Trial Mitigation Area would
ensure that the northern Gulf of America ship shock trial box is
situated outside of the Rice's whale core distribution area identified
in 2019 (84 FR 15446, April 15, 2019). These restrictions will reduce
the severity of impacts to Rice's whales by reducing their exposure to
levels of sound from sonar or explosives that would have the potential
to cause injury or mortality, thereby further supporting NMFS'
determination that non-auditory injury and mortality are not expected
to occur, reducing the likelihood of auditory injury, and, further,
minimizing the severity of behavioral disturbance. Further, as
described in the Changes from the Proposed Rule to the Final Rule
section of this final rule, we have added three new measures in the
Rice's Whale Mitigation Area since publication of the proposed rule.
This final rule includes a requirement that the Action Proponents must
not detonate explosive sonobuoys within 3 nmi (5.6 km) of the Rice's
Whale Mitigation Area as well as two new measures to further reduce the
risk of vessel strike of Rice's whale. The Action Proponents must avoid
conducting vessel propulsion testing events in the Rice's Whale
Mitigation Area to the maximum extent practical and the Action
Proponents must issue an annual awareness message to Navy vessels that
routinely train or test in the vicinity of the Rice's whale proposed
critical habitat and Coast Guard vessels that routinely train anywhere
in the Gulf of America.
While it is not practicable for the Action Proponents to issue
speed restrictions (see section 5 (Mitigation Considered but
Eliminated) of the 2025 AFTT SEIS/OEIS), as suggested by the commenter,
this annual awareness message will advise that risk of whale strike is
increased when transiting through Rice's whale proposed critical
habitat (i.e., within the 100 to 400 m isobaths), particularly at night
or during periods of reduced visibility, and reinforce the requirement
of the COLREGS (https://www.imo.org/en/about/conventions/pages/colreg.aspx) for vessels to proceed at a safe speed, appropriate for
the prevailing circumstances and conditions, to avoid a collision with
any sighted object or disturbance, including any marine mammal.
Regarding the recommendation for surface ships to minimize transits
and transit distances through Rice's whale habitat to the maximum
extent practicable, Navy asserts that it does not have many training
events in the area, and vessel traffic in the area is already limited.
As such, transits through this area are already minimized, as
recommended by the commenter.
Regarding the commenter's recommendation to revise the boundaries
of the Rice's Whale Mitigation Area westwards to include all U.S.
waters between the 100-m and 400-m isobaths, the majority of the Navy's
activities do not occur within the central/western portion of Rice's
whale habitat. The potential for impacts in that area is very low due
to infrequent use of Navy surface ship hull-mounted MFAS or explosives
in the central/western portion of the habitat. The Coast Guard does
train in this area but
[[Page 50518]]
their training activities do not include the use of sonar and other
transducers or explosives (of note, the Coast Guard is not planning any
testing activities as part of the specified activity in the AFTT Study
Area). As such, the only applicable mitigation requirement for the
waters west of the Rice's Whale Mitigation Area between the 100-m and
400-m isobaths is for the Action Proponents to issue an annual
awareness message to Navy vessels that routinely train or test in the
vicinity of the Rice's whale proposed critical habitat and for the
Coast Guard to send the awareness messages required in the Rice's Whale
Mitigation Area to all Coast Guard vessels that routinely train
anywhere in the Gulf of America, and this final rule includes a
requirement for the Action Proponents to do so.
Regarding the Commission's recommendation related to a future
Rice's whale sightings platform (e.g., WhaleAlert, WhaleMap), when such
a platform is established, NMFS and the Action Proponents will evaluate
its potential use for mitigating potential impacts to Rice's whale,
including providing sightings data to the Lookouts prior to them
standing watch, use of the data to inform the Lookouts' visual
observations during vessel transits, and potential speed restrictions
in a defined time and area relative to sightings. In the public comment
related to the Commission's, the commenter stated that its
recommendations account for the fact that an Early Warning System for
Rice's whale does not yet exist, but it is unclear what the commenter
is referring to regarding providing Lookouts the sightings data prior
to standing watch to help inform visual observations absent a sighting
platform such as WhaleMap, and as such, this final rule does not
incorporate this recommendation.
Comment 23: A commenter stated that while it provisionally supports
aspects of the proposed rule, the least practicable adverse impact
standard has not yet been met. The commenter provided specific
mitigation recommendations in support of their assertion.
Response: NMFS has described our well-reasoned process for
identifying the measures needed to meet the least practicable adverse
impact standard in the Mitigation Measures section in this rule, and we
have followed the approach described there when analyzing potential
mitigation for the Action Proponents' activities in the AFTT Study
Area. Responses to specific recommendations for mitigation measures
provided by the commenters are discussed separately.
Comment 24: A commenter recommended that NMFS incorporate new
scientific information into design of its mitigation areas,
specifically referencing Houser et al. (2024) and Southall et al.
(2024). The commenter recommended that NMFS use the data to inform
which types of acoustic sources to limit in mitigation areas important
to particular species, and the size of the stand-off distances to apply
to those areas.
Response: The mitigation measures in this rule are informed by
multiple factors, including the sensitivity of certain hearing groups
to certain sound sources (informed by the Phase IV criteria and
thresholds) and vulnerability to other threats (e.g., vessel strike).
The Phase IV criteria and thresholds incorporate data from Houser et
al. (2024), and as such, the mitigation areas in the proposed rule and
final rule inherently consider those data. While the Phase IV criteria
and thresholds do not incorporate data from Southall et al. (2024),
they include delphinid response data from other studies, and the
potential responses observed in Southall et al. (2024) occurred at
received levels and distances assessed for potentially significant
behavioral responses in the AFTT analysis. The commenter did not
provide specific mitigation recommendations that may stem from the
publications they reference. However, NMFS has responded to other
mitigation recommendations from the commenter in separate responses
herein and has explained that it has determined that the Action
Proponents' planned mitigation measures would effect the least
practicable adverse impact on the affected species and their habitat.
Comment 25: A commenter stated that the proposed measure to
minimize the use of helicopter dipping sonar to the maximum extent
practicable in the Southeast North Atlantic Right Whale Mitigation Area
is a step toward mitigation of impacts from dipping sonar. However, the
commenter states that the available scientific evidence on the impacts
of dipping sonar on deep-dive rates in beaked whales (family
Ziphiidae), indicates that management of this acoustic source should be
expanded, including to areas within the AFTT Study Area representing
important habitat for beaked whale populations.
Response: As stated in the Analysis and Negligible Impact
Determination section of the proposed rule and this final rule, there
are no known BIAs for beaked whales in the AFTT Study Area, though
these stocks generally occur in higher densities year-round in deep
waters over the Atlantic continental shelf margins. The Western North
Atlantic stocks of goose-beaked whales and Blainville's beaked whales
generally congregate over continental shelf margins from Canada to
North Carolina, with goose-beaked whales reported as far south as the
Caribbean and Blainville's beaked whales as far south as the Bahamas.
The Western North Atlantic stock of Gervais' beaked whales generally
congregate over continental shelf margins from New York to North
Carolina. The Western North Atlantic stock of Sowerby's beaked whales
is the most northerly distributed stock of deep-diving mesoplodonts,
and they generally congregate over continental shelf margins from
Labrador to Massachusetts. The Western North Atlantic stock of True's
beaked whales generally congregate over continental shelf margins from
Nova Scotia to Cape Hatteras, with northern occurrence likely relating
to the Gulf Stream. The Western North Atlantic stock of northern
bottlenose whales is uncommon in U.S. waters and generally congregates
in areas of high relief, including shelf breaks and submarine canyons
from the Davis Strait to New England, although strandings have occurred
as far south as North Carolina.
The commenter provided a general recommendation for expansion of
dipping sonar mitigation in important habitat for beaked whales but did
not specify particular areas or beaked whale species to prioritize for
such mitigation. As noted above, while beaked whales generally occur in
higher densities year-round in deep waters over the Atlantic
continental shelf margins, the latitudinal ranges vary depending on the
species. If the entire shelf break were considered important habitat
for beaked whales, that would limit the bathymetric scope of areas
available for the training and testing of dipping sonar and would not
be practical.
As the commenter notes, the proposed rule and this final rule
include a Southeast North Atlantic Right Whale Mitigation Area in which
the Action Proponents must minimize the use of helicopter dipping sonar
to the maximum extent practical. This measure would benefit the Western
North Atlantic stocks of goose-beaked whales and Blainville's beaked
whales in the most southern portion of their range. The proposed rule
and this final rule also include Major Training Exercise Planning
Awareness Mitigation Areas across multiple areas along the Atlantic
continental shelf break in which the Action Proponents must either
limit major training exercises
[[Page 50519]]
(MTEs) or not conduct MTEs. These restrictions would benefit multiple
beaked whale species, and would inherently limit or prohibit dipping
sonar, as the majority of dipping sonar used during training activities
in the mid-Atlantic is used during MTEs (unit-level training mostly
occurs in the Jacksonville Operating Area (OPAREA)). Also of note, the
Action Proponents already do not conduct much sonar in some beaked
whale habitats, such as the Cape Hatteras area where goose-beaked
whales are known to occur. This location was chosen for the Atlantic
BRS on beaked whales specifically because those beaked whales are not
frequently exposed to mid-frequency active sonar. Additional
restrictions on the use of dipping sonar in the Atlantic is not
practicable, and as such, is not required by this final rule.
Comment 26: A commenter stated that, to reflect the best available
scientific information and achieve the least practicable adverse impact
to NARW, the boundaries of the Northeast North Atlantic Right Whale
Mitigation Area should be extended to include the established foraging
habitat south of Martha's Vineyard and Nantucket, Massachusetts.
Response: NMFS concurs with the commenter that additional
mitigation is warranted in the NARW feeding area south of Martha's
Vineyard and Nantucket. As such, this final rule includes a new
Martha's Vineyard North Atlantic Right Whale Mitigation Area in which
the Action Proponents must avoid conducting vessel propulsion testing
events to the maximum extent practical. In addition to the new Martha's
Vineyard North Atlantic Right Whale Mitigation Area, this final rule
includes multiple new mitigation measures for NARW, as described in
response to Comment 21, including new measures in the Dynamic North
Atlantic Right Whale Mitigation Area, which overlaps the new Martha's
Vineyard North Atlantic Right Whale Mitigation Area. In this area, the
Action Proponents will provide North Atlantic Right Whale Dynamic
Management Area information (e.g., location and dates) to applicable
assets transiting and training or testing in the vicinity of the
Dynamic Management Area. Further, in PMAP reports generated in the
Dynamic North Atlantic Right Whale Mitigation Area, Action Proponents
will provide the WhaleMap web address (https://www.whalemap.org),
advise situations in which risk of vessel strike is increased, and
reinforce the requirement for vessels to proceed at a safe speed.
Additional details on the above can be found in the response to Comment
21. Additionally, in the Dynamic North Atlantic Right Whale Mitigation
Area, during propulsion testing in the mitigation area, to the maximum
extent practical, Lookouts will be provided recent https://www.whalemap.org sightings data to help inform visual observations.
Further, the Action Proponents follow NARW sighting and avoidance
measures regardless of location, including one or more Lookouts on
manned underway surface vessels in accordance with the most recent
navigation safety instruction and underway manned surface vessels
maneuver themselves (which may include reducing speed) to maintain 500
yd (457.2 m) distance from whales, as mission and circumstances allow.
Within the northeast portion of the Study Area, the Northeast North
Atlantic Right Whale Mitigation Area represents the largest area that
is practical for the Navy to implement that full suite of mitigation.
As such, this final rule does not require that the Action Proponents
extend the boundary of the Northeast North Atlantic Right Whale
Mitigation Area (and the mitigation required in that area) south of
Martha's Vineyard and Nantucket for the reasons described below.
Expanding the full suite of mitigation measures of the Northeast North
Atlantic Right Whale Mitigation Area to the area south of Nantucket and
Martha's Vineyard would encroach upon the primary water space where
training and testing activities are planned to occur. Such
modifications of training and testing activities would have a
significant impact on safety, sustainability, and the Navy's ability to
meet its mission requirements.
The Navy does not typically schedule MTEs in the Northeast Range
Complexes, though MTEs originally planned for other locations may have
to change during an exercise, or in exercise planning, based on an
assessment of the performance of the units, or due to other conditions
such as weather and mechanical issues. These contingency requirements
preclude the Navy from completely eliminating MTEs from occurring in
this area. For training and testing that does occur here, this area
provides a wide range of bathymetric and topographic opportunities that
support critical smaller scale training and testing necessary to meet
mission requirements.
The area is important to the Navy's acoustic and oceanographic
research. Specifically, having access to waterspace within 20 nmi (37
km) of Woods Hole Oceanographic Institute and in the vicinity of the
New England Mud Patch is important to these research activities.
Restricting the area would result in a reduced ability to conduct
accurate oceanographic or acoustic research to meet research
objectives, validate acoustic models, and conduct accurate engineering
tests of acoustic sources, signal processing algorithms, and acoustic
interactions.
Additionally, NAVSEA needs full access and flexibility to conduct
testing in this area. Testing locations are typically located near
systems command support facilities, which provide critical safety,
platform, and infrastructure support and technical expertise necessary
to conduct testing. Restricting the area would result in: (1) reduced
ability to ensure the safety, functionality, and accuracy of systems,
platforms, and components through maintenance, repairs, or testing
prior to use at sea as needed or required by acquisition milestones,
and (2) reduced ability to effectively test systems, platforms, and
components before full-scale production or delivery in order to
validate whether they perform as expected and determine whether they
are operationally effective, suitable, survivable, and safe for their
intended use by the fleet.
Comment 27: A commenter recommended further research and
exploration of the feasibility of signal modification, including
converting upsweeps to downsweeps, reducing the level of the side
bands, or lengthening the rise time. The 2024 AFTT Draft Supplemental
EIS/OEIS considered, but rejected, modification of active sonar sources
for training as part of a potential mitigation measure (``26. Reducing
annual active sonar hours, replacing active sonar, with passive sonar
or modifying active sonar sources for training''), deeming it
impractical for achieving the mission. The commenter stated that the
rationale provided in the 2024 AFTT Draft Supplemental EIS/OEIS does
not clearly justify why signal modifications alone would be
impractical. The commenter states that some of those modifications,
such as converting up-sweeps to down-sweeps, would not alter the
system's spectral output in any way. The commenter stated that it
believes source modification requires greater validation across species
and in more behavioral contexts before any decisions are made to alter
signals--but, given the preliminary data, and given the potential of
this measure to reduce the instances and severity of behavioral
harassment, it urges NMFS to require or otherwise stimulate
investigation of this potentially significant mitigation measure and
provide a schedule for completion.
[[Page 50520]]
Another commenter stated that NMFS and Navy should prioritize
identifying and implementing alternative training methods,
technologies, and locations that do not place vulnerable marine life at
such extreme risk, stating that this would not only fulfill legal
obligations, but also demonstrate a commitment to sustainable
stewardship of our ocean ecosystems.
Response: Active sonar signals are designed explicitly to provide
optimum performance at detecting underwater objects (e.g., submarines)
in a variety of acoustic environments. The Action Proponents train with
various active sonar signals, including up-sweeps and down-sweeps, to
accurately replicate operational scenarios. Reducing training realism
by restricting the signal used would ultimately prevent units from
deploying with the required level of readiness necessary to accomplish
their missions and impede the Action Proponents' ability to certify
forces to deploy to meet national security tasking. Likewise, testing
program requirements include test parameters designed to accurately
determine whether a system is meeting its operational and performance
requirements. Reducing realism by restricting the signal used would
impact the ability of researchers, program managers, and weapons system
acquisition programs to effectively test systems and platforms (and
components of these systems and platforms) before full-scale production
or delivery to the fleet. For these reasons, the Navy has determined,
and NMFS concurs, that modifying or limiting the sonar signal as
mitigation is impractical to implement as it would result in degraded
realism of training and testing.
NMFS and the Navy will explore whether future studies on the
efficacy and practicality of signal modification are appropriate in
consideration of other ongoing research efforts, including some
recommended by the commenter (e.g., thermal detection). However, at
this time, given the numerous other research priorities and established
impracticality, NMFS is not requiring the Action Proponents to
investigate the efficacy of signal modification.
Comment 28: The Commission recommended that NMFS require Action
Proponents' surface ships to maintain a speed of no more than 10 kn
(18.5 km/hr) during transits when a NARW is observed, if the vessels
are within 5 nmi (9.3 km) of a reported sighting, at night, and during
periods of reduced visibility in the Northeast North Atlantic Right
Whale Mitigation Area year-round and the Southeast North Atlantic Right
Whale Mitigation Area from November 15 to April 15. The Commission also
recommended that NMFS require Action Proponents' surface ships to
maintain a speed of no more than 10 kn (18.5 km/hr) during transits
when a Rice's whale is observed, at night, and during periods of
reduced visibility in the Rice's Whale Mitigation Area year-round.
In a related comment, a commenter stated that according to the
current vessel speed rule that was put into place to protect NARWs,
military vessels are exempt from the speed restrictions. The commenter
states that increasing naval vessel traffic in these same regions,
especially when military vessels are exempt from civilian speed
restrictions, will only heighten the risk of fatal interactions.
Response: The proposed rule included multiple requirements to
minimize the risk of vessel strike to NARW and Rice's whales, including
a requirement within the Northeast North Atlantic Right Whale
Mitigation Area requiring surface ships to implement speed reductions
after observing a NARW, if transiting within 5 nmi (9.3 km) of a
sighting reported to the North Atlantic Right Whale Sighting Advisory
System within the past week, and when transiting at night or during
periods of reduced visibility. It also included a requirement in the
Southeast North Atlantic Right Whale Mitigation Area that from November
15 to April 15 requiring surface ships to minimize north-south transits
to the maximum extent practical, and implement speed reductions after
they observe a NARW, if they are within 5 nmi (9.3 km) of an Early
Warning System sighting reported within the past 12 hours, and at night
and in poor visibility. This final rule includes several additional
measures to reduce the risk of vessel strike, as described below.
Within the Southeast North Atlantic Right Whale Mitigation Area,
from November 15 to April 15, the Action Proponents must not conduct
vessel propulsion testing. Further, this final rule includes a new
Martha's Vineyard North Atlantic Right Whale Mitigation Area in which
the Action Proponents must avoid conducting vessel propulsion testing
events to the maximum extent practical. Additionally, in the Dynamic
North Atlantic Right Whale Mitigation Area, the extent of which matches
the boundary of the U.S. EEZ on the East Coast, the Action Proponents
must provide North Atlantic Right Whale Dynamic Management Area
information (e.g., location and dates) to applicable assets transiting
and training or testing in the vicinity of the Dynamic Management Area.
The information must alert assets (and their Lookouts) to the possible
presence of NARW in their vicinity. Lookouts must use the information
to help inform visual observations during military readiness activities
that involve vessel movements, active sonar, in-water explosives
(including underwater explosives and explosives deployed against
surface targets), or non-explosive ordnance deployed against surface
targets in the mitigation area.
In PMAP reports generated in the Dynamic North Atlantic Right Whale
Mitigation Area, this final rule requires that Action Proponents must
provide the WhaleMap web address (https://whalemap.org) and advise that
risk of whale strike is increased after: (1) observing a NARW; (2) when
operating within 5 nmi (6.5 km) of a known sighting reported within the
past 24 hours; (3) within a NMFS-designated Seasonal Management Area,
Dynamic Management Area, or Slow Zone; and (4) when transiting at night
or during periods of reduced visibility. The PMAP report must also
reinforce the requirement of the COLREGS for vessels to proceed at a
safe speed, appropriate for the prevailing circumstances and
conditions, to avoid a collision with any sighted object or
disturbance, including any marine mammal. Additionally, this final rule
requires that during propulsion testing in the Dynamic North Atlantic
Right Whale Mitigation Area, to the maximum extent practical, Lookouts
must be provided recent https://whalemap.org sightings data to help
inform visual observations.
This final rule also requires that within the first year of AFTT
Phase IV implementation, the Action Proponents must work
collaboratively with the NMFS ESA Interagency Cooperation Division and
the NMFS Permits and Conservation Division to: (1) analyze and discuss
the application of new information from the NMFS North Atlantic Right
Whale Persistence Modelling Efforts toward AFTT mitigation measures;
(2) evaluate the practicability and conservation benefits of newly
proposed mitigation measures and/or changes to existing measures based
on information from the model; and (3) implement any new mitigation
measures or changes to existing measures that meet the Action
Proponents' Practicability Criteria and Sufficiently Beneficial
requirements.
This final rule also includes two new measures to reduce the risk
of vessel strike of Rice's whale. The Action Proponents must avoid
conducting vessel propulsion testing events in the Rice's Whale
Mitigation Area, to the maximum extent practical. The Action
[[Page 50521]]
Proponents must also issue an annual awareness message to Navy and
Coast Guard vessels that routinely train or test in the vicinity of the
proposed Rice's whale proposed critical habitat. The message will
advise that risk of whale strike is increased when transiting through
proposed Rice's whale proposed critical habitat (i.e., within the 100-
400 m isobaths), particularly at night or during periods of reduced
visibility, and reinforce the requirement of the COLREGS for vessels to
proceed at a safe speed, appropriate for the prevailing circumstances
and conditions, to avoid a collision with any sighted object or
disturbance, including any marine mammal.
The Action Proponents require flexibility in use of variable ship
speeds for training, testing, operational, safety, and engineering
qualification requirements. Action Proponent vessels typically use the
lowest speed practical given individual mission needs. NMFS has
reviewed the analysis of these additional suggested restrictions and
the impacts they would have on military readiness and concurs with the
Navy's assessment that they are impracticable (see section 5.3.4.1
Vessel Movement and section 5.5 Measures Considered but Eliminated in
the 2020 NWTT FSEIS/OEIS). Therefore, the Action Proponents are already
planning to engage in the lowest practicable speed in biologically
important habitats, including in designated critical habitat for NARW
and proposed critical habitat for Rice's whales and other biologically
important habitat for vulnerable species, as well as in all mitigation
areas and other areas. As such, additional restrictions on vessel speed
are not practicable and therefore, are not required.
The commenter did not provide a citation for the statement that
naval vessel traffic is increasing in the AFTT Study Area. The Navy
states that there has not been an increase in vessel traffic related to
AFTT activities since the 2018 analysis. Rather, there has been a
decrease in most areas and a decrease in the AFTT Study Area as a whole
(see table 3.0-9 of the 2025 AFTT Supplemental EIS/OEIS).
Comment 29: A commenter asserted that mitigation measures based on
visual observation (i.e., by Lookouts), such as safety zone
maintenance, results in highly limited risk reduction for most species
and under most conditions. The commenter stated that NMFS should
require infrared and thermal detection technologies as alternative
detection measures for mitigation and monitoring, stating that these
technologies have achieved a readiness level that is capable of
supporting monitoring and mitigation during Phase IV military readiness
activities.
Response: Lookouts remain an important component of the Action
Proponents' mitigation strategy, especially as it relates to minimizing
exposure to the more harmful impacts that may occur within closer
proximity to the source, where Lookouts are most effective. As stated
by the commenter, thermal detection technologies have advanced in
recent years. However, significant limitations still exist, and the
technology has not yet reached the level of performance needed for
deployment during military readiness activities for mitigation uses.
Current technologies are limited by: (1) low sensor resolution and a
narrow field of view; (2) reduced performance in certain environmental
conditions; and (3) high cost and uncertain long-term reliability.
Thermal detection systems are more useful for detecting marine
mammals in some marine environments than others. Current technologies
have limitations regarding water temperature and survey conditions
(e.g., rain, fog, sea state, glare, ambient brightness), for which
further effectiveness studies are required. Thermal detection systems
are generally thought to be most effective in cold environments, which
have a large temperature differential between an animal's temperature
and the environment. Current thermal detection systems have proven more
effective at detecting large whale blows than the bodies of small
animals, particularly at a distance. The effectiveness of current
technologies has not been demonstrated for small marine mammals at-sea
(noting that Richter et al. (2023) demonstrated efficacy in detecting
killer whales in the Salish Sea using land-based thermal imaging
systems). Thermal detection systems exhibit varying degrees of false
positive detections (i.e., incorrect notifications) due in part to
their low sensor resolution and reduced performance in certain
environmental conditions. False positive detections may incorrectly
identify other features (e.g., birds, waves, boats) as marine mammals
(Boebel and Zitterbart, 2017; Zitterbart et al., 2020).
Thermal detection systems for military applications are deployed on
various Department of Defense (DoD) platforms. These systems were
initially developed for nighttime targeting and object detection such
as a boat, vehicle, or people and are not optimized for marine mammal
detections versus object detection, nor do these systems have the
automated marine mammal detection algorithms the Navy is testing via
its ongoing research program. The Action Proponents do not have
available personnel to add Lookouts to use thermal detection systems in
tandem with existing Lookouts who are using traditional observation
techniques.
Existing specialized DoD infrared/thermal capabilities on Navy
aircraft and surface ships are designed for fine-scale targeting.
Viewing arcs of these thermal systems are narrow and focused on a
target area. Furthermore, sensors are typically used only in select
training events and have a limited lifespan before requiring expensive
replacement. Some sensor elements can cost upward of $300,000 to
$500,000 per device, so their use is predicated on a distinct military
need.
The Office of Naval Research sponsored a project from 2019 to 2023
titled ``Development of the Next Generation Automatic Surface Whale
Detection System for Marine Mammal Mitigation and Distribution
Estimation.'' The aim of the project was to develop a system to be used
by non-experts, with minimal installation requirements, applying
algorithms to reliably detect, localize, and identify surfaced marine
mammals from a vessel, while minimizing false detections. In 2024, the
project transitioned to the Navy's Living Marine Resources Program, the
applied research, development, test, and evaluation program that funds
Navy driven research needs to support at-sea compliance and permitting.
Thermal Imaging for Vessel Strike Mitigation on Autonomous Vessels
(Project #LMR-68) will focus on adapting and testing two existing and
proven thermal imaging-based whale detection systems to reduce the
potential for vessel strike during navigation of unmanned Navy surface
vessels.
When infrared and thermal mitigation technologies mature to the
state where they are determined to be sufficiently effective at
mitigating marine mammal impacts when considering the range of
environmental conditions analogous to where the Action Proponents train
and test and the species that could co-occur in space and time with the
activities, then the Action Proponents will assess their compatibility
with military readiness applications on both manned and unmanned
vessels. This would include a practicality assessment of the budget and
acquisition process (including costs associated with designing,
building, installing, maintaining, and manning equipment), the
logistical and physical considerations for retrofitting platforms with
the appropriate equipment and their associated maintenance, repairs, or
replacements (e.g., conducting
[[Page 50522]]
engineering studies to ensure compatibility with existing shipboard
systems), the resource considerations for training personnel to
effectively operate the equipment, and the potential security and
classification issues. New system integration on Action Proponents'
assets can entail up to 5-10 years of effort to account for
acquisition, engineering studies, and development and execution of
systems training.
Given the assessment above, this final rule does not require the
Action Proponents to utilize thermal detection for mitigating training
and testing impacts on marine mammals. As thermal detection technology
improves and practicability of applying the technology for training and
testing activities is further assessed, NMFS will consider whether
requirements to utilize thermal detection for mitigating impacts to
marine mammals is appropriate.
Negligible Impact Determination
Comment 30: A commenter stated that NMFS has not met the negligible
impact standard based on current scientific understanding and
population status of species like the Rice's whale and NARW. The
commenter states that authorizing incidental takes in areas that are
biologically sensitive, federally protected, and home to critically
endangered species sets a dangerous precedent.
In a related comment, a commenter identified six points that they
described as methodological problems that require addressing to ensure
the negligible impact determinations are valid under the MMPA and
Administrative Procedure Act (APA). The six points were: (1) improper
reliance on means and medians in establishing thresholds for auditory
impacts; (2) application of an unrealistic non-conservative auditory
weighting scheme for low-frequency cetaceans; (3) lack of incorporation
of recent behavioral response data into biphasic risk functions; (4)
reduction of modeled take estimates through the application of cut-off
distances; (5) discounting gas-bubble pathology as a mechanism of harm
to marine mammals; and (6) failure to present a meaningful analysis of
the aggregate effects on marine mammal populations.
Response: NMFS disagrees with the commenter's assertion that the
negligible impact standard has not been satisfied for each species or
stock. The commenter has not provided sufficient information to support
their assertion.
As described in the proposed rule and this final rule, serious
injury or mortality of NARW and Rice's whale is neither anticipated nor
authorized, nor is any non-auditory injury. The maximum allowable take
is limited to Level A and B harassment in the form of AUD INJ (table
16). As described in the Auditory Injury from Sonar Acoustic Sources
and Explosives and Non-Auditory Injury from Explosives section of the
proposed rule, any take that occurs in the form of TTS is expected to
be lower-level, of short duration (from minutes to, at most, several
hours or less than a day), and mostly not in a frequency band that
would be expected to interfere with NARW or Rice's whale communication
or other important low-frequency cues. Any associated lost
opportunities or capabilities individuals might experience as a result
of TTS would not be at a level or duration that would be expected to
impact reproductive success or survival.
NMFS carefully considered the population status and best scientific
evidence available for Rice's whale, NARW, and all other marine mammal
species and stocks in making its negligible impact determinations. NMFS
has worked with the Navy over the years to increase the spatio-temporal
specificity of the descriptions of activities planned in or near areas
of biological importance, when possible (i.e., in NARW ESA-designated
critical habitat). NMFS' analysis includes explicit consideration of
takes occurring in important areas, as included in appendix A of the
application, and inclusion of mitigation measures in areas of
biological importance, where appropriate. NMFS may still find that the
impacts of a specified activity are negligible even where take occurs
in BIAs, critical habitat, or other important areas, and even though
impacts in these protected areas warrant additional consideration,
including potential mitigation.
As described in the Analysis and Negligible Impact Determination
section and the Mitigation Measures section of the proposed rule and
this final rule, mitigation measures, several of which are designed
specifically to reduce impacts to NARW and Rice's whale, are expected
to further reduce the potential severity of impacts through real-time
operational measures that minimize higher level/longer duration
exposures and time/area measures that reduce impacts in high value
habitat. Specifically, this rule includes several geographic mitigation
areas for NARW: Northeast North Atlantic Right Whale Mitigation Area,
Gulf of Maine Mitigation Area, Martha's Vineyard North Atlantic Right
Whale Mitigation Area, Jacksonville Operating Area North Atlantic Right
Whale Mitigation Area, Southeast North Atlantic Right Whale Mitigation
Area, Dynamic North Atlantic Right Whale Mitigation Area, Major
Training Exercise Planning Awareness Mitigation Areas in the northeast
and mid-Atlantic, and ship shock trial mitigation areas. The Northeast
North Atlantic Right Whale Mitigation Area and Southeast North Atlantic
Right Whale Mitigation Area in particular would reduce exposures in
times and areas where impacts would be more likely to affect feeding
and energetics, or important cow/calf interactions that could lead to
reduced reproductive success or survival, including those in areas
known to be biologically important, and such impacts are not
anticipated. For example, any impacts predicted in the NARW migratory
corridor BIA along the East Coast are less likely to impact individuals
during feeding or breeding behaviors.
For Rice's whale, this rulemaking includes a Rice's Whale
Mitigation Area that overlaps the Rice's whale small and resident
population area identified by NMFS in its 2016 status review (Rosel et
al., 2016) and most of the eastern portion of proposed critical habitat
(88 FR 47453, July 24, 2023). Within this area, the Action Proponents
must not use more than 200 hours of surface ship hull-mounted MFAS
annually and must not detonate in-water explosives (including
underwater explosives and explosives deployed against surface targets)
except during mine warfare activities. Additionally, the Ship Shock
Trial Mitigation Area would ensure the northern Gulf of America ship
shock trial box is situated outside of the Rice's whale core
distribution area identified in 2019 (84 FR 15446). These restrictions
would reduce the severity of impacts to Rice's whales by reducing their
exposure to levels of sound from sonar or explosives that would have
the potential to cause injury or mortality, thereby reducing the
likelihood of those effects and, further, minimizing the severity of
behavioral disturbance.
Responses to the six ``methodological problems'' are included in
NMFS response to Comments 5, 8-11, and 13.
Comment 31: The Commission recommended that NMFS use the two-tiered
approach from NMFS' 2020 Criteria for Determining Negligible Impact
under MMPA Section 101(a)(5)(E) (NMFS, 2020), including using single
negligible impact threshold (NITs) instead of 10 percent of
potential biological removal (PBR), for informing its negligible impact
determinations that involve M/SI for the final rule and other
incidental take authorizations involving M/SI. The Commission asserts
that this
[[Page 50523]]
would provide consistency within NMFS' own policy directive.
Response: As stated in the proposed rule (90 FR 19858, May 9,
2025), on June 17, 2020, NMFS finalized new Criteria for Determining
Negligible Impact under MMPA section 101(a)(5)(E). The guidance
explicitly notes the differences in the negligible impact
determinations required under section 101(a)(5)(E), as compared to
sections 101(a)(5)(A) and 101(a)(5)(D). As stated in the guidance,
first, they differ in terms of the types of take being considered and
consequently, the effects of the takes on population dynamics. In
paragraphs (a)(5)(A) and (D) of section 101, NMFS must determine if the
taking by harassment, injury, or mortality (or a combination of these)
incidental to specified activities will have a negligible impact. In
section 101(a)(5)(E), NMFS must determine if M/SI incidental to
commercial fisheries will have a negligible impact. NMFS considers
mortalities and serious injuries to be removals from the population
that can be evaluated using well-documented models of population
dynamics, whereas harassment and non-serious injury (sub-lethal taking)
are not considered to be removals from the population. Second, they
differ in whether they apply to all marine mammal stocks or only those
stocks or species listed under the ESA: paragraphs (a)(5)(A) and (D) of
section 101 apply to all marine mammal stocks (regardless of ESA
listing status or MMPA depleted status), while paragraph (a)(5)(E)
applies only to stocks designated as depleted because of their listing
under the ESA. The guidance further specifies that the procedure in
that document is limited to how the agency conducts negligible impact
analyses for commercial fisheries under section 101(a)(5)(E) (i.e., it
is not intended to be a broad policy directive for M/SI analyses for
all activities). As described in the Serious Injury and Mortality
section of this final rule, when considering PBR during evaluation of
effects of M/SI under section 101(a)(5)(A), we utilize a two-tiered
analysis for each stock for which M/SI is proposed for authorization:
Tier 1: Compare the total human-caused average annual M/SI estimate
from all sources, including the M/SI proposed for authorization from
the specific activity, to PBR. If the total M/SI estimate is less than
or equal to PBR, then the specific activity is considered to have a
negligible impact on that stock. If the total M/SI estimate (including
from the specific activity) exceeds PBR, conduct the Tier 2 analysis.
Tier 2: Evaluate the estimated M/SI from the specified activity
relative to the stock's PBR. If the M/SI from the specified activity is
less than or equal to 10 percent of PBR and other major sources of
human-caused mortality have mitigation in place, then the individual
specified activity is considered to have a negligible impact on that
stock. If the estimate exceeds 10 percent of PBR, then, absent other
mitigating factors, the specified activity could be considered likely
to have a non-negligible impact on that stock.
In this final rule, NMFS has described its method for considering
PBR to evaluate the effects of potential mortality in the negligible
impact analysis. NMFS has reviewed the 2020 guidance and determined
that our consideration of PBR in the evaluation of mortality, as
described in the Serious Injury and Mortality section of the proposed
rule and in this final rule, remains appropriate for use in the
negligible impact analysis for the Action Proponents' activities under
section 101(a)(5)(A). As such, NMFS disagrees with Commission's
recommendation to use NMFS (2020) to inform its negligible impact
determinations that involve M/SI.
Other Comments
Comment 32: A commenter stated that the manuscripts for the East
Coast and Gulf of America region BIAs have not yet been published;
however, to the best of the commenter's knowledge, the scientific
analysis has been completed and is available to NMFS for decision-
making purposes. This scientific analysis represents the best available
scientific information and should be incorporated into NMFS' impact
analysis.
Response: NMFS and the Action Proponents considered the best
available science in developing the proposed rule and this final rule,
including as it relates to BIAs for marine mammals. While the
manuscripts for updated East Coast and Gulf of America region BIAs have
not yet been published, NMFS and the Navy coordinated with the authors
in development of the proposed rule to understand likely updates to the
BIAs and consider the updated science they would rely upon.
Changes From the Proposed Rule to the Final Rule
Between publication of the proposed rule and development of the
final rule, additional mitigation measures have been added in response
to public comments and further proposals by the Action Proponents.
New mitigation measures were added in the following mitigation
areas: (1) Southeast North Atlantic Right Whale Mitigation Area, (2)
Dynamic North Atlantic Right Whale Mitigation Area, (3) Rice's Whale
Mitigation Area, and (4) Major Training Exercise Planning Awareness
Mitigation Areas.
In the Southeast North Atlantic Right Whale Mitigation Area, this
final rule includes two new requirements. First, from November 15 to
April 15, the Action Proponents must not detonate explosive sonobuoys
within 3 nmi (5.6 km) of the Southeast North Atlantic Right Whale
Mitigation Area. Second, during the same time period, the Action
Proponents must not conduct vessel propulsion testing.
In PMAP reports generated in the Dynamic North Atlantic Right Whale
Mitigation Area, this final rule requires that Action Proponents must
provide the WhaleMap web address (https://whalemap.org) and advise that
risk of whale strike is increased after: (1) observing a NARW; (2) when
operating within 5 nmi (6.5 km) of a known sighting reported within the
past 24 hours; (3) within a NMFS-designated Seasonal Management Area,
Dynamic Management Area, or Slow Zone; and (4) when transiting at night
or during periods of restricted visibility. The PMAP report must also
reinforce the requirement of the COLREGS for vessels to proceed at a
safe speed, appropriate for the prevailing circumstances and
conditions, to avoid a collision with any sighted object or
disturbance, including any marine mammal. Further, this final rule
requires that sightings data must be used when planning propulsion
testing event details (e.g., timing, location, duration) to minimize
impacts to NARW to the maximum extent practical. During propulsion
testing in the Dynamic North Atlantic Right Whale Mitigation Area, to
the maximum extent practical, Lookouts must be provided recent https://whalemap.org sightings data to help inform visual observations. Last,
this final rule clarifies that the extent of the mitigation area
matches the boundary of the U.S. EEZ on the East Coast (i.e., the full
extent of where NMFS could potentially establish Dynamic Management
Areas).
In the Rice's Whale Mitigation Area, this final rule includes a
requirement that the Action Proponents must not detonate explosive
sonobuoys within 3 nmi (5.6 km) of the Rice's Whale Mitigation Area as
well as two new measures to further reduce the risk of vessel strike of
Rice's whale. The Action Proponents must avoid conducting vessel
propulsion testing events in the Rice's Whale Mitigation Area, to the
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maximum extent practical. The Action Proponents must also issue an
annual awareness message to Navy vessels that routinely train or test
in the vicinity of the Rice's Whale proposed critical habitat, and
Coast Guard vessels that routinely train anywhere in the Gulf of
America. The message will advise that risk of whale strike is increased
when transiting through Rice's whale proposed critical habitat (i.e.,
within the 100-400 m (328-1,312 ft) isobaths), particularly at night or
during periods of restricted visibility, and reinforce the requirement
of the COLREGS for vessels to proceed at a safe speed, appropriate for
the prevailing circumstances and conditions, to avoid a collision with
any sighted object or disturbance, including any marine mammal.
In the combined Major Training Exercise Planning Awareness
Mitigation Areas located in the Gulf of America, this final rule
includes a requirement that the Action Proponents must not conduct any
MTEs in the mitigation area.
In the Dynamic North Atlantic Right Whale Mitigation Area,
Northeast North Atlantic Right Whale Mitigation Area, Southeast North
Atlantic Right Whale Mitigation Area, and Rice's Whale Mitigation Area,
the term ``reduced visibility'' and ``poor visibility'' were updated to
``restricted visibility'' to align with the COLREGS used by the Action
Proponents to train and test Lookouts.
In addition to the new measures within the existing mitigation
areas, this final rule includes a new Martha's Vineyard North Atlantic
Right Whale Mitigation Area in which the Action Proponents must avoid
conducting vessel propulsion testing events to the maximum extent
practical.
Regarding activity-based mitigation, this final rule clarifies that
the Navy must implement soft start techniques for impact pile driving.
Of note, Navy continues to consider soft-start procedures as part of
their standard operating procedures, and as such, they are not listed
as a mitigation measure in the 2025 AFTT Supplemental EIS/OEIS.
Additionally, a new measure requires that for all activities involving
explosives, if a marine mammal is visibly injured or killed as a result
of detonation, explosives use in the event must be suspended
immediately. This final rule also includes language that describes
instances when activity-based mitigation for physical disturbance and
strike stressors will not be implemented. These are listed in the
Activity-Based Mitigation for Physical Disturbance and Strike Stressors
section of this final rule.
Further, within the first year of AFTT Phase IV implementation, the
Action Proponents must work collaboratively with the NMFS ESA
Interagency Cooperation Division and the NMFS Permits and Conservation
Division to: (1) analyze and discuss the application of new information
from the NMFS North Atlantic Right Whale Persistence Modelling Efforts
toward AFTT mitigation measures; (2) evaluate the practicability and
conservation benefits of newly proposed mitigation measures and/or
changes to existing measures based on information from the model; and
(3) implement any new mitigation measures or changes to existing
measures that meet the Action Proponents' Practicability Criteria and
Sufficiently Beneficial requirements.
This final rule also includes a requirement for cetacean live-
stranding or near-shore atypical milling events. These requirements
have previously been included in the Notification and Reporting Plan
only. In the event of a cetacean live stranding (or near-shore atypical
milling) event within the AFTT Study Area or within 50 km (27 nmi) of
the boundary of the AFTT Study Area, where the NMFS Stranding Network
is engaged in herding or other interventions to return animals to the
water, NMFS Office of Protected Resources (OPR) will advise the Action
Proponents of the need to implement shutdown procedures for all active
acoustic sources or explosive devices within 50 km of the stranding.
Following this initial shutdown, NMFS will communicate with the Action
Proponents to determine whether circumstances support modification of
the shutdown zone. The Action Proponents may decline to implement all
or part of the shutdown if the holder of the LOA, or his/her designee,
determines that it is necessary for national security. Shutdown
procedures for live stranding or milling cetaceans include the
following:
If at any time, the marine mammal(s) die or are
euthanized, or if herding/intervention efforts are stopped, NMFS will
immediately advise that the shutdown around the animals' location is no
longer needed;
Otherwise, shutdown procedures will remain in effect until
NMFS determines and advises that all live animals involved have left
the area (either of their own volition or following an intervention);
and
If further observations of the marine mammals indicate the
potential for re-stranding, additional coordination will be required to
determine what measures are necessary to minimize that likelihood
(e.g., extending the shutdown or moving operations farther away) and to
implement those measures as appropriate.
Regarding reporting requirements, in addition to those included in
the proposed rule, this final rule requires that in the Annual AFTT
Training and Testing Reports, Navy personnel must confirm that foreign
military use of sonar and explosives, when such militaries are
participating in a U.S. Navy-led exercise or event, combined with the
Action Proponents' use of sonar and explosives, would not cause
exceedance of the analyzed levels within each NAEMO modeled sonar and
explosive bin used for estimating predicted impacts.
NMFS also made several updates to its analysis in this final rule.
Since publication of the proposed rule, the Society for Marine
Mammalogy revised the taxonomy for Atlantic white-sided dolphin
(Lagenorhynchus acutus) by reassigning the species to the genus
Leucopleurus. The scientific name of the species is now Leucopleurus
acutus, which has been updated in table 1. Further, in the Group and
Species-Specific Analyses section, NMFS has updated the reproductive
strategy of Bryde's-like whales (i.e., Bryde's whales, Rice's whales)
to ``income'' rather than capital, the movement ecology of Rice's
whales to ``resident'' rather than nomadic, based on Constantine et al.
(2018) and Izadi et al. (2018), as summarized in Garrison et al.
(2024). Additionally, the Commission identified an error related to
potential impacts to goose-beaked whales (Western North Atlantic stock)
in the Preliminary Assessment and Negligible Impact Determination
section of the proposed rule. This final rule includes a correction to
that language to indicate that the impacts to the Western North
Atlantic stock of goose-beaked whales could cause a limited number of
females to forego reproduction for a year.
Description of Marine Mammals and Their Habitat in the Area of
Specified Activities
Marine mammal species and their associated stocks that have the
potential to occur in the AFTT Study Area are presented in table 1
along with each stock's ESA and MMPA statuses, abundance estimate and
associated coefficient of variation (CV) value, minimum abundance
estimate (Nmin), PBR, annual M/SI, and potential occurrence
in the AFTT Study Area. The Action Proponents anticipate take of
individuals of 41 marine mammal species (81 stocks) by Level A and
Level B harassment incidental to military readiness activities from the
use of
[[Page 50525]]
sonar and other transducers, in-water explosives, air guns, pile
driving/extraction, and vessel movement in the AFTT Study Area. The
AFTT proposed rule included additional information about the species in
this rule, marine mammal species for which take is not authorized,
marine mammal species which could occur in the area but are not managed
by NMFS, marine mammal hearing, National Marine Sanctuaries, and the
2010 Deepwater Horizon (DWH) oil spill, all of which remains valid and
applicable but has not been reprinted in this final rule. NMFS hereby
refers to the information and analysis provided in the proposed rule
(90 FR 19858, May 9, 2025) which continue to apply to this final rule.
Information on the status, distribution, abundance, population
trends, habitat, and ecology of marine mammals in the AFTT Study Area
may be found in section 4 of the 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 2025 AFTT Supplemental EIS/OEIS. Table 1 incorporates
the best available science, including data from the U.S. Atlantic and
Gulf of Mexico Marine Mammal Stock Assessment Report (SAR; Hayes et
al., 2024) (now referred to as the Gulf of America; see https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments), and 2024 draft SAR, as well as monitoring data from
the Navy's marine mammal research efforts. NMFS has also reviewed
scientific literature published since publication of the proposed rule
and determined that none of this new information nor any other new
information available changes our determination of which species have
the potential to be affected by the Action Proponents' activities or
the information pertinent to status, distribution, abundance,
population trends, habitat, or ecology of the species in this final
rulemaking, except as noted below.
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Below, we consider additional information about the marine mammals
in the area of the specified activities that informs our analysis, such
as identifying known areas of important habitat or behaviors, or where
unusual mortality events (UME) have been designated.
Critical Habitat
Currently, only the NARW has ESA-designated critical habitat in the
AFTT Study Area. However, NMFS recently published a proposed rule
proposing new ESA-designated critical habitat for the Rice's whale (88
FR 47453, July 24, 2023).
North Atlantic Right Whale
On February 26, 2016, NMFS issued a final rule (81 FR 4838) to
replace the critical habitat for NARW with two new critical habitat
areas. The areas now designated as critical habitat contain
approximately 29,763 nmi\2\ (102,084 km\2\) of marine habitat in the
Gulf of Maine and Georges Bank region (Unit 1), essential for NARW
foraging and off the Southeast U.S. coast (Unit 2), including the coast
of North Carolina, South Carolina, Georgia, and Florida, which are key
areas essential for calving. These two ESA-designated critical habitats
were established to replace three smaller previously ESA-designated
critical habitats (Cape Cod Bay/Massachusetts Bay/Stellwagen Bank,
Great South Channel, and the coastal waters of Georgia and Florida in
the southeastern United States) that had been designated by NMFS in
1994 (59 FR 28805, June 3, 1994). Two additional areas in Canadian
waters, Grand Manan Basin and Roseway Basin, were identified and
designated as critical habitat under Canada's endangered species law
(section 58 (5) of the Species at Risk Act (SARA), S. C. 2002, c. 29)
and identified in Final Recovery Strategy for the NARW, posted June
2009 on the SARA Public Registry.
Unit 1 encompasses the Gulf of Maine and Georges Bank region
including the large embayments of Cape Cod Bay and Massachusetts Bay
and deep underwater basins, as well as state waters, except for inshore
areas, bays, harbors, and inlets, from Maine through Massachusetts in
addition to Federal waters, all of which are key areas (see figure 4.1-
1 of the application). It also does not include waters landward of the
72 COLREGS lines (33 CFR part 80). The essential physical and
biological features of foraging habitat for NARW are: (1) the physical
oceanographic conditions and structures of the Gulf of Maine and
Georges Bank region that combine to distribute and aggregate Calanus
finmarchicus for right whale foraging, namely prevailing currents and
circulation patterns, bathymetric features (basins, banks, and
channels), oceanic fronts, density gradients, and temperature regimes;
(2) low flow velocities in Jordan, Wilkinson, and Georges Basins that
allow diapausing C. finmarchicus to aggregate passively below the
convective layer so that the copepods are retained in the basins; (3)
late stage C. finmarchicus in dense aggregations in the Gulf of Maine
and Georges Bank region; and (4) diapausing C. finmarchicus in
aggregations in the Gulf of Maine and Georges Bank region.
Unit 2 consists of all marine waters from Cape Fear, North
Carolina, southward to approximately 27 nmi (50 km) below Cape
Canaveral, Florida, within the area bounded on the west by the
shoreline and the 72 COLREGS lines, and on the east by rhumb lines
connecting the specific points described below (see figure 4.1-2 of the
application). The essential physical and biological features correlated
with the distribution of NARW in the southern critical habitat area
provide an optimum environment for calving. These essential physical
and biological features are: (1) calm sea surface conditions of Force 4
or less on the Beaufort Wind Scale; (2) sea surface temperatures from a
minimum of 44.6 degrees Fahrenheit ([deg]F) (7 [deg]Celsius (C)), and
never more than 62.6 [deg]F (17 [deg]C); and (3) water depths of 19.7
to 91.9 ft (6 to 28 m), where these features simultaneously co-occur
over contiguous areas of at least 231 nmi\2\ (792.3 km\2\) of ocean
waters during the months of November through April. For example, the
bathymetry of the inner and nearshore middle shelf area minimizes the
effect of strong winds and offshore waves, limiting the formation of
large waves and rough water. The average temperature of critical
habitat waters is cooler during the time right whales are present due
to a lack of influence by the Gulf Stream and cool freshwater runoff
from coastal areas. The water temperatures may provide an optimal
balance between offshore waters that are too warm for nursing mothers
to tolerate, yet not too cool for calves that may have only minimal
fatty insulation. Reproductive females and calves are expected to be
concentrated in the critical habitat from December through April.
Rice's Whale
On August 23, 2021, NMFS published a final rule that revised the
listing of Rice's whales under the ESA to reflect the change in the
scientifically accepted taxonomy and nomenclature of this species (86
FR 47022). Prior to this revision, the Rice's whale was listed in 2019
under the ESA as an endangered subspecies of the Bryde's whale (Gulf of
America subspecies (referred to as the Gulf of Mexico subspecies in 86
FR 47022)). The 2019 listing rule indicated that, with a total
abundance of approximately 100 individuals, small population size and
restricted range are the most serious threats to this species (84 FR
15446, April 15, 2019). However, other threats such as energy
exploration, development, and production; oil spills and oil spill
responses; vessel collision; fishing gear entanglement; and
anthropogenic noise were also identified as threats that contribute to
the risk of extinction.
The specific occupied areas proposed for designation as critical
habitat for the Rice's whale contain approximately 28,270.65 mi\2\
(73,220.65 km\2\) of continental shelf and slope associated waters
between the 100-400 m (328-1,312 ft) isobaths within the Gulf of
America spanning from the U.S. EEZ boundary off the southwestern coast
of Texas, to the boundary between the South Atlantic Fishery Management
Council and the Gulf Fishery Management Council off the southeastern
coast of Florida.
In the final listing rule, NMFS stated that critical habitat was
not determinable at the time of the listing, because sufficient
information was not currently available on the geographical area
occupied by the species (84 FR 15446, April 15, 2019). On July 24,
2023, NMFS published a proposed rule describing the proposed critical
habitat designation, including supporting information on Rice's whale
biology, distribution, and habitat use, and the methods used to develop
the proposed designation (88 FR 47453). The physical and biological
features essential to the conservation of the species identified in the
proposed rule are: (1) sufficient density, quality, abundance, and
accessibility of small demersal and vertically migrating prey species,
including scombriformes, stomiiformes, myctophiformes, and myopsida;
(2) marine water with (i) elevated productivity, (ii) bottom
temperatures of 50-66.2 [deg]F (10-19 [deg]C), and (iii) levels of
pollutants that do not preclude or inhibit any demographic function;
and (3) sufficiently quiet conditions for normal use and occupancy,
including intraspecific communication, navigation, and detection of
prey, predators, and other threats.
Biologically Important Areas
LaBrecque et al. (2015) identified BIAs within U.S. waters of the
East Coast and Gulf of America (referred to as the Gulf of Mexico in
the LaBrecque
[[Page 50545]]
et al. (2015)), which represent areas and times in which cetaceans are
known to concentrate in areas of known importance for activities
related to reproduction, feeding, and migration, or areas where small
and resident populations are known to occur. Unlike ESA critical
habitat, these areas are not formally designated pursuant to any
statute or law but are a compilation of the best available science
intended to inform impact and mitigation analyses. An interactive map
of the BIAs is available here: https://oceannoise.noaa.gov/biologically-important-areas. In some cases, additional, or newer,
information regarding known feeding, breeding, or migratory areas may
be available, and is included below.
On the East Coast, 19 of the 24 identified BIAs fall within or
overlap with the AFTT Study Area: 10 feeding (2 for minke whale, 1 for
sei whale, 3 for fin whale, 3 for NARW, and 1 for humpback), 1
migration (NARW), 2 reproduction (NARW), and 6 small and resident
population (1 for harbor porpoise and 5 for bottlenose dolphin).
Figures 4.1-1 through 4.1-14 of the application illustrate how these
BIAs overlap with OPAREAs on the East Coast. In the Gulf of America, 4
of the 12 identified BIAs for small and resident populations overlap
the AFTT Study Area (1 for Rice's (Bryde's) whale and 3 for bottlenose
dolphin). Figures 4.1-9 through 4.1-13 of the application illustrates
how these BIAs overlap with OPAREAs in the Gulf of America.
Large Whales Feeding BIAs--East Coast
Two minke whale feeding BIAs are located in the northeast Atlantic
from March through November in waters less than 200 m (656 ft) in the
southern and southwestern section of the Gulf of Maine including
Georges Bank, the Great South Channel, Cape Cod Bay and Massachusetts
Bay, Stellwagen Bank, Cape Anne, and Jeffreys Ledge (LaBrecque et al.,
2015a; LaBrecque et al., 2015b). LaBrecque et al. (2015b) delineated a
feeding area for sei whales in the northeast Atlantic between the 25-m
(82-ft) contour off coastal Maine and Massachusetts to the 200-m (656-
ft) contour in central Gulf of Maine, including the northern shelf
break area of Georges Bank. The feeding area also includes the southern
shelf break area of Georges Bank from 100 m to 2,000 m (328 ft to 6,562
ft) and the Great South Channel. Feeding activity is concentrated from
May through November with a peak in July and August. LaBrecque et al.
(2015b) identified three feeding areas for fin whales in the North
Atlantic within the AFTT Study Area: (1) June to October in the
northern Gulf of Maine; (2) year-round in the southern Gulf of Maine,
and (3) March to October east of Montauk Point. LaBrecque et al.
(2015b) delineated a humpback whale feeding area in the Gulf of Maine,
Stellwagen Bank, and Great South Channel.
North Atlantic Right Whale BIAs--East Coast and Additional Information
LaBrecque et al. (2015b) identified three seasonal NARW feeding
areas BIAs located in or near the AFTT Study Area: (1) February to
April on Cape Cod Bay and Massachusetts Bay; (2) April to June in the
Great South Channel and on the northern edge of Georges Bank; and (3)
June to July and October to December on Jeffreys Ledge in the western
Gulf of Maine. A mating BIA was identified in the central Gulf of Maine
(from November through January), a calving BIA in the southeast
Atlantic (from mid-November to late April) and the migratory corridor
area BIA along the U.S. East Coast between the NARW southern calving
grounds and northern feeding areas (see figures 4.1-1 through 4.1-14 of
the application for how these BIAs overlap with Navy OPAREAs).
In addition to the BIAs described above, an area south of Martha's
Vineyard and Nantucket, primarily along the western side of Nantucket
Shoals, was recently described as an important feeding area (Kraus et
al., 2016; O'Brien et al., 2022, Quintano-Rizzo et al., 2021). Its
importance as a foraging habitat is well established (Leiter et al.,
2017; Estabrook et al., 2022; O'Brien et al., 2022). Nantucket Shoals'
unique oceanographic and bathymetric features, including a persistent
tidal front, help sustain year-round elevated phytoplankton biomass and
aggregate zooplankton prey for NARW (White et al., 2020; Quintana-Rizzo
et al., 2021). O'Brien et al. (2022) hypothesize that NARW southern New
England habitat use has increased in recent years (i.e., over the last
decade) as a result of either, or a combination of, a northward shift
in prey distribution (thus increasing local prey availability) or a
decline in prey in other abandoned feeding areas (e.g., Gulf of Maine).
Pendleton et al. (2022) characterize southern New England as a
``waiting room'' for NARW in the spring, providing sufficient, although
sub-optimal, prey choices while NARW wait for C. finmarchicus supplies
in Cape Cod Bay (and other primary foraging grounds like the Great
South Channel) to optimize as seasonal primary and secondary production
progresses. Throughout the year, southern New England provides
opportunities for NARW to capitalize on C. finmarchicus blooms or
alternative prey (e.g., Pseudocalanus elongatus and Centropages
species, found in greater concentrations than C. finmarchicus in
winter), although likely not to the extent provided seasonally in more
well-understood feeding habitats like Cape Cod Bay in late spring or
the Great South Channel (O'Brien et al., 2022). Although extensive data
gaps, highlighted in a recent report by the National Academy of
Sciences (NAS) (2023), have prevented development of a thorough
understanding of NARW foraging ecology in the Nantucket Shoals region,
it is clear that the habitat was historically valuable to the species
given historic whaling activity there. It has become increasingly
valuable over the last decade.
Harbor Porpoise BIA--East Coast
LaBrecque et al. (2015b) identified a small and resident population
BIA for harbor porpoise in the Gulf of Maine (see figure 4.1-14 of the
application). From July to September, harbor porpoises are concentrated
in waters less than 150 m (492 ft) deep in the northern Gulf of Maine
and southern Bay of Fundy. During fall (October to December) and spring
(April to June), harbor porpoises are widely dispersed from New Jersey
to Maine, with lower densities farther north and south (LaBrecque et
al., 2015b).
Bottlenose Dolphin BIA--East Coast
LaBrecque et al. (2015b) identified nine small and resident
bottlenose dolphin population areas within estuarine areas along the
east coast of the U.S. (see figure 4.1-11 of the application). These
areas include estuarine and nearshore areas extending from Pamlico
Sound, North Carolina down to Florida Bay, Florida (LaBrecque et al.,
2015b). The Northern North Carolina Estuarine System, Southern North
Carolina Estuarine System, and Charleston Estuarine System populations
partially overlap with nearshore portions of the Navy Cherry Point
Range Complex, and Jacksonville Estuarine System Populations partially
overlap with nearshore portions of the Jacksonville Range Complex. The
Southern Georgia Estuarine System Population area also overlaps with
the Jacksonville Range Complex, specifically within Naval Submarine
Base Kings Bay, Kings Bay, Georgia and includes estuarine and
intercoastal waterways from Altamaha Sound to the Cumberland River
(LaBrecque et al., 2015b). The remaining
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four BIAs are outside but adjacent to the AFTT Study Area boundaries.
Bottlenose Dolphin BIA--Gulf of America
LaBrecque et al. (2015) also described 11 year-round BIAs for small
and resident estuarine stocks of bottlenose dolphin that primarily
inhabit inshore waters of bays, sounds, and estuaries (BSE) in the Gulf
of America (see figures 4.1-12 and 4.1-13 in the application). Of the
11 BIAs identified for the BSE bottlenose dolphins in the Gulf of
America, 3 overlap with the Gulf Range Complex (Aransas Pass Area,
Texas; Mississippi Sound Area, Mississippi; and St. Joseph Bay Area,
Florida), while 8 are located adjacent to the AFTT Study Area
boundaries.
Rice's (Previously Bryde's) Whale BIA--Gulf of America
The Rice's (previously Bryde's) whale is a very small population
that is genetically distinct from Bryde's whales and not genetically
diverse within the Gulf of America (Rosel and Wilcox, 2014; Rosel et
al., 2021). Further, the species is typically observed only within a
narrowly circumscribed area within the eastern Gulf of America.
Therefore, this area is described as a year-round BIA by LaBrecque et
al. (2015). Previous survey effort covered all oceanic waters of the
U.S. Gulf of America, and whales were observed only between
approximately the 100- and 300-m (328- and 984-ft) isobaths in the
eastern Gulf of America from the head of the De Soto Canyon (south of
Pensacola, Florida) to northwest of Tampa Bay, Florida (Maze-Foley and
Mullin, 2006; Waring et al., 2016; Rosel and Wilcox, 2014; Rosel et
al., 2016). Rosel et al. (2016) expanded this description by stating
that, due to the depth of some sightings, the area is more
appropriately defined to the 400-m (1,312-ft) isobath and westward to
Mobile Bay, Alabama, in order to provide some buffer around the deeper
sightings and to include all sightings in the northeastern Gulf of
America. Since then, passive acoustic detections of Rice's whale have
occurred in the north central and western Gulf of America (Soldevilla
et al., 2022; Soldevilla et al., 2024), although the highest densities
of Rice's whales have been confined to the northeastern Gulf of America
core habitat. The number of individuals that occur in the central and
western Gulf of America and nature of their use of this area is poorly
understood. Soldevilla et al. (2022) suggest that more than one
individual was present on at least one occasion, as overlapping calls
of different call subtypes were recorded in that instance, but also
state that call detection rates suggest that either multiple
individuals are typically calling or that individual whales are
producing calls at higher rates in the central and western Gulf of
America. Soldevilla et al. (2024) provide further evidence that Rice's
whale habitat encompasses all 100-400 m (328-1,312 ft) depth waters
encircling the entire Gulf of America, including Mexican waters (as
described in the proposed critical habitat designation (88 FR 47453,
July 24, 2023)), but they also note that further research is needed to
understand the density of whales in these areas, seasonal changes in
whale density, and other aspects of habitat usage.
Unusual Mortality Events
A UME is defined under section 410(9) of the MMPA as a stranding
that is unexpected; involves a significant die-off of any marine mammal
population; and demands immediate response. Three UMEs with ongoing
investigations in the AFTT Study Area that inform our analysis are
discussed below. The 2022 Maine Pinniped UME has closed and the 2018
Northeast Pinniped UME is non-active and pending closure.
North Atlantic Right Whale (2017-Present)
Beginning in 2017, elevated mortalities in NARW were documented in
Canada and the United States and necessitated a UME be declared. The
whales impacted by the UME include dead, injured, and sick individuals,
who represent more than 20 percent of the population, which is a
significant impact on an endangered species where deaths are outpacing
births. Additionally, research demonstrates that only about one-third
of right whale deaths are documented. The preliminary cause of
mortality, serious injury, and morbidity (sublethal injury and illness)
in most of these whales is from entanglements or vessel strikes.
Endangered NARW are approaching extinction. There are approximately 372
individuals remaining, including fewer than 70 reproductively active
females. Human impacts continue to threaten the survival of this
species. The many individual whales involved in the UME are a
significant setback to the recovery of this endangered species.
Since 2017, dead, seriously injured, sublethally injured, or ill
NARW along the U.S. and Canadian coasts have been documented,
necessitating a UME declaration and investigation. The leading category
for the cause of death for this ongoing UME is ``human interaction,''
specifically from entanglements or vessel strikes. As of September 4,
2025, there have been 41 confirmed mortalities (dead, stranded, or
floating) and 39 seriously injured free-swimming whales for a total of
80 whales. The UME also considers animals with sublethal injury or
illness (i.e., ``morbidity''; n = 76) bringing the total number of
whales in the UME to 156. More information about the NARW UME is
available online at: https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2025-north-atlantic-right-whale-unusual-mortality-event.
Humpback Whale (2017-Present)
Since January 2016, elevated humpback whale mortalities have
occurred along the Atlantic coast from Maine to Florida. This event was
declared a UME in April 2017. Partial or full necropsy examinations
have been conducted on approximately half of the 257 known cases (as of
September 4, 2025). Of the whales examined (approximately 90), about 40
percent had evidence of human interaction either from vessel strike or
entanglement. While a portion of the whales have shown evidence of pre-
mortem vessel strike, this finding is not consistent across all whales
examined and more research is needed. NOAA is consulting with
researchers that are conducting studies on the humpback whale
populations, and these efforts may provide information on changes in
whale distribution and habitat use that could provide additional
insight into how these vessel interactions occurred. More information
is available at: https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2025-humpback-whale-unusual-mortality-event-along-atlantic-coast.
Minke Whale (2017-Present)
Elevated minke whale mortalities detected along the Atlantic coast
from Maine through South Carolina resulted in the declaration of an on-
going UME in 2017. As of September 4, 2025, a total of 205 minke whales
have stranded during this UME. Full or partial necropsy examinations
were conducted on more than 60 percent of the whales. Preliminary
findings show evidence of human interactions or infectious disease, but
these findings are not consistent across all of the minke whales
examined, so more research is needed. More information is available at:
https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2025-minke-whale-unusual-mortality-event-along-atlantic-coast.
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Phocid Seals (2018-2020, 2022)
Harbor and gray seals have experienced two UMEs since 2018,
although one was recently closed (2022 Pinniped UME in Maine) and
closure of the other, described here, is pending. Beginning in July
2018, elevated numbers of harbor seal and gray seal mortalities
occurred across Maine, New Hampshire, and Massachusetts. Additionally,
stranded seals have shown clinical signs as far south as Virginia,
although not in elevated numbers, therefore the UME investigation
encompassed all seal strandings from Maine to Virginia. A total of
3,152 reported strandings (of all species) occurred from July 1, 2018,
through March 13, 2020. Full or partial necropsy examinations were
conducted on some of the seals and samples were collected for testing.
Based on tests conducted thus far, the main pathogen found in the seals
is phocine distemper virus. NMFS is performing additional testing to
identify any other factors that may be involved in this UME, which is
pending closure. Information on this UME is available online at:
https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
We provided a detailed discussion of the potential effects of the
specified activities on marine mammals and their habitat in our
proposed rule (90 FR 19858, May 9, 2025). NMFS hereby refers to the
information and analysis provided in the proposed rule which continue
to apply to this final rule. In the Potential Effects of Specified
Activities on Marine Mammals and Their Habitat section of the proposed
rule, NMFS provided a description of the ways marine mammals may be
affected by these activities in the form of, among other things,
serious injury or mortality, physical trauma, sensory impairment
(permanent and TTS and acoustic masking), physiological responses
(particularly stress responses), behavioral disturbance, or habitat
effects. All of this information remains valid and applicable.
Therefore, we do not reprint the information here but refer the reader
to that document.
NMFS has also reviewed new relevant information from the scientific
literature since publication of the proposed rule. Summaries of the new
key scientific literature reviewed since publication of the proposed
rule are presented below.
Cur[eacute] et al. (2025) examined the effects of MFAS received
level and source distance on the behavioral responses of 14 tagged male
sperm whales off northern Norway. Behavioral responses were scored
using the severity scale from Southall et al. (2021), with probability
and severity of behavioral responses (e.g., changes in vocal and dive
behaviors, avoidance, cessation of feeding or resting, locomotion or
orientation changes) increasing with higher received levels (maximum
sound exposure level) and closer source proximities. From observations,
modeling indicates that beyond 14 km (7.6 nmi) no significant
behavioral responses are predicted regardless of received level.
Wensveen et al. (2025), using the same animals from Cur[eacute] et
al. (2025), concluded that source proximity (close: vessels
transmitting MFAS starting at 7.4 km (4 nmi) while approaching focal
whale vs. distant: vessels transmitting MFAS starting 14.8 km (8 nmi)
while approaching focal whale) influenced sperm whale behavioral
responses by resulting in decreased foraging time with increased
received levels and decreased source proximity, as well as short-term
sensitization with subsequent exposure sessions. Specifically, sperm
whales were found to increase time in a non-foraging behavioral state
or produced a decrease in buzzes (indicative of reduced prey capture)
when foraging with MFAS exposure.
Henderson et al. (2025) examined the potential behavioral effects
of Navy Submarine Command Courses (SCC) involving MFAS (i.e., hull-
mounted; sonobuoys; helicopter-dipping) off the Pacific Islands Missile
Range Facility (PMRF) on three satellite-tagged Blainville's beaked
whales (there was a fourth tagged individual but it did not remain on
the range during MFAS exposure). Behavioral responses showed individual
variation but short-term changes in dive behavior and horizontal
movements were detected. However, only temporary horizontal avoidance
was observed, with animals remaining near PMRF (within 10s of
kilometers) throughout the SCC and in two situations returning to PMRF
after the SCC was completed. Received levels were up to 150 dB, with
sources closest points of approach (CPAs) at 18 km (9.7 nmi).
Previous marine mammal TTS studies have followed the trend that
susceptibility to noise-induced hearing loss reflects baseline hearing
thresholds by frequency (i.e., audiogram; where frequencies with lower
baseline thresholds (lowest point in audiogram) being more susceptible
to threshold shifts from noise than frequencies with higher baseline
thresholds (at edges of hearing range)). Kastelein et al. (2025a)
examined this trend using three species (harbor porpoise, California
sea lion, and harbor seal) with similar baseline hearing thresholds
(59-61 dB) at 8 kHz. Despite similar baseline thresholds at 8 kHz, TTS
onset (6 dB threshold shift) varied among the species: 169 dB
cumulative SEL for harbor porpoise, 176 dB cumulative SEL for
California sea lion, and 182 dB cumulative SEL for harbor seal. Thus,
despite similar baseline thresholds at 8 kHz, susceptibility varies
among species and confirms it is not appropriate extrapolated data
between species.
Kastelein et al. (2025b) examined TTS in two harbor seals exposed
to one-sixth octave band noise centered 8 kHz. In this study, TTS onset
(6 dB threshold shift) occurred at approximately 181 dB cumulative SEL,
which is 6 dB higher than what is predicted with the current Navy Phase
IV criteria (i.e., current Navy Phase IV criteria is considered more
protective). Furthermore, the equal energy hypothesis is supported
based on the noise exposure scenarios (e.g., frequency, duration, sound
pressure levels) used in this study.
Having considered the new information, along with information
provided in public comments on the proposed rule, we have determined
that there is no new information that substantively affects our
analysis of potential impacts on marine mammals and their habitat that
appeared in the proposed rule, all of which remains applicable and
valid for our assessment of the effects of the Action Proponents'
activities during the 7-year period of this rule.
Estimated Take of Marine Mammals
This section indicates the number of takes NMFS is authorizing,
which is based on the amount of take NMFS anticipates is reasonably
likely to occur. NMFS coordinated closely with the Action Proponents in
the development of their incidental take application and agrees that
the methods the Action Proponents have put forth described herein to
estimate take (including the model, thresholds, and density estimates),
and the resulting numbers are based on the best available science and
appropriate for authorization.
The 2025 AFTT Supplemental EIS/OEIS considered all military
readiness activities planned to occur in the AFTT Study Area that have
the potential to result in the MMPA defined take of marine mammals. The
Action Proponents determined that the three stressors below could
result in the incidental taking of marine mammals.
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NMFS has reviewed the Action Proponents' data and analysis and
determined that it is complete and accurate, and agrees that the
following stressors have the potential to result in takes by harassment
of marine mammals from the specified activities:
Acoustics (sonars and other transducers, air guns, pile
driving/extraction);
Explosives (explosive shock wave and sound, assumed to
encompass the risk due to fragmentation); and
Vessel strike.
Acoustic and explosive sources are likely to result in incidental
takes of marine mammals by harassment. Explosive sources and vessel
strikes have the potential to result in incidental take by injury,
serious injury, and/or mortality.
For this military readiness activity, section 3(18)(B) of the MMPA
(16 U.S.C. 1362(18)(B)) defines ``harassment'' as: (1) 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 (2) 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 the behavioral patterns are
abandoned or significantly altered (Level B harassment).
Authorized takes are primarily in the form of Level B harassment,
as use of the acoustic (e.g., active sonar, pile driving, and air guns)
and explosive sources is most likely to result in 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 disturbance) for
marine mammals, either via direct behavioral disturbance or TTS. There
is also the potential for Level A harassment, in the form of AUD INJ to
result from exposure to the sound sources utilized in military
readiness activities. Lastly, no more than 6 serious injuries or
mortalities total (over the 7-year period) of large whales could
potentially occur through vessel strikes, and 13 serious injuries or
mortalities (over the 7-year period) from explosive use. Although we
analyze the impacts of these potential serious injuries or mortalities
that are authorized, the required mitigation and monitoring measures
are expected to minimize the likelihood (i.e., further lower the
already low probability) that vessel strike (and the associated serious
injury or mortality) would occur, as well as the severity of other
takes (including serious injury or mortality from use of explosives).
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
would experience behavioral disturbance or incur some degree of
temporary or permanent hearing impairment; (2) the area or volume of
water that would be ensonified above these levels in a day or event;
(3) the density or occurrence of marine mammals within these ensonified
areas; and (4) the number of days of activities or events.
We provided a detailed discussion of the acoustic thresholds,
acoustic effects modeling and estimation, range to effects for
stressors, and marine mammal density information in our proposed rule
(90 FR 19858, May 9, 2025). NMFS hereby refers to the information and
analysis provided in the proposed rule which continue to apply to this
final rule. In the Estimated Take of Marine Mammals section of the
proposed rule, we identified the subset of potential effects that would
be expected to qualify as take both annually and over the 7-year period
covered by the rule, then identified the maximum number of takes we
believe could occur (mortality) or are reasonably expected to occur
(harassment) based on the methods described. All of this information
remains valid and applicable. Therefore, we do not repeat the
information here, but refer the reader to the proposed rule.
Estimated Take From Acoustic Stressors
The quantitative analysis process used for the 2025 AFTT
Supplemental EIS/OEIS and the application to estimate potential
exposures to marine mammals resulting from acoustic and explosive
stressors is detailed in the Acoustic Impacts Technical Report.
Regarding how avoidance of loud sources is considered in the take
estimation, NAEMO does not simulate horizontal animat movement during
an event. However, NAEMO approximates marine mammal avoidance of high
sound levels due to exposure to sonars in a one-dimensional calculation
that scales how far an animat would be from a sound source based on
sensitivity to disturbance, swim speed, and avoidance duration. This
process reduces the SEL, defined as the accumulation for a given
animat, by reducing the received SPL of individual exposures based on a
spherical spreading calculation from sources on each unique platform in
an event. The onset of avoidance was based on the BRFs. Avoidance
speeds and durations were informed by a review of available exposure
and baseline data. This method captures a more accurate representation
of avoidance by using the received sound levels, distance to platform,
and species-specific criteria to calculate potential avoidance for each
animat than the approach used in Phase III. However, this avoidance
method may underestimate avoidance of long-duration sources with lower
sound levels because it triggers avoidance calculations based on the
highest modeled SPL received level exceeding p(0.5) on the BRF, rather
than on cumulative exposure. This is because initiation of the
avoidance calculation is based on the highest modeled SPL received
level over p(0.5) on the BRF. Please see section 4.4.2.2 of the
Acoustic Impacts Technical Report.
Regarding the consideration of mitigation effectiveness in the take
estimation, during military readiness activities, there is typically at
least one, if not numerous, support personnel involved in the activity
(e.g., range support personnel aboard a torpedo retrieval boat or
support aircraft). In addition to the Lookout posted for the purpose of
mitigation, these additional personnel observe and disseminate marine
species sighting information amongst the units participating in the
activity whenever possible as they conduct their primary mission
responsibilities. However, the quantitative analysis does not reduce
model-estimated impacts to account for activity-based mitigation, as
was done in previous phases of AFTT. While the activity-based
mitigation is not quantitatively included in the take estimates, table
2.3-1 of appendix A of the application indicates the percentage of the
modeled instances of take where an animal's closest point of approach
was within a mitigation zone and, therefore, AUD INJ could potentially
be mitigated. Note that these percentages do not account for other
factors, such as the sightability of a given species or viewing
conditions.
Unlike activity-based mitigation, in some cases, implementation of
the geographic mitigation areas is reflected in the quantitative
analysis. The extent to which the mitigation areas reduce impacts on
the affected species is addressed in the Analysis and Negligible Impact
Determination section.
For additional information on the quantitative analysis process,
refer to the Acoustic Impacts Technical Report and sections 6 and 11 of
the application.
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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 pieces of the Navy's take
estimation methods (e.g., propagation models, animat movement models,
and behavioral thresholds). NMFS evaluates the acceptability of these
pieces as they evolve and are used in different rules and impact
analyses. Some of the pieces of the Action Proponents' take estimation
process have been used in Navy incidental take rules since 2009 and
undergone multiple public comment processes; all of them have undergone
extensive internal Navy review, and all of them have undergone
comprehensive review by NMFS, which has sometimes resulted in
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, NAEMO is the result of a NMFS-led Center for Independent
Experts review of the components used in earlier models. The acoustic
propagation component of NAEMO (titled CASS/GRAB) is accredited by the
Oceanographic and Atmospheric Master Library (OAML), and many of the
environmental variables used in NAEMO come from approved OAML databases
and are based on in-situ data collection. The animal density components
of NAEMO are base products of the Navy Marine Species Density Database
(NMSDD), which includes animal density components that have been
validated and reviewed by a variety of scientists from NMFS science
centers and academic institutions. Several components of the model, for
example the Duke University habitat-based density models, have been
published in peer reviewed literature. Additionally, NAEMO simulation
components underwent quality assurance and quality control (commonly
referred to as 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.
In summary, we believe the Action Proponents' methods, including
the method for incorporating avoidance, are the most appropriate
methods for predicting AUD INJ, non-auditory injury, TTS, and
behavioral disturbance. But even with the consideration of avoidance,
given some of the more conservative components of the methodology
(e.g., the thresholds do not consider auditory threshold shift recovery
between pulses), 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 AUD INJ, non-auditory
injury, TTS, or behavioral disturbance.
Based on the methods discussed in the previous sections and NAEMO,
the Action Proponents provided their take estimate and request for
authorization of takes incidental to the use of acoustic and explosive
sources for military readiness activities annually (based on the
maximum number of activities that could occur per 12-month period) and
over the 7-year period, as well as the Navy's take request for ship
shock trials, covered by the application. The following species/stocks
present in the AFTT Study Area were modeled by the Navy and estimated
to have zero takes of any type from any activity source: Barataria Bay
Estuarine, Calcasieu Lake, Central Georgia Estuarine System,
Chokoloskee Bay Ten Thousand Islands Gullivan Bay, Charleston
Estuarine, Copano Bay Aransas Bay San Antonio Bay Redfish Bay Espiritu,
Mississippi River Delta, and Northern South Carolina Estuarine System
stocks of bottlenose dolphin. Further, modeled activities did not
overlap the Puerto Rico and U.S. Virgin Islands stock of sperm whale,
and therefore these stocks are estimated to have zero takes of any
type. NMFS has reviewed the Action Proponents' 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 and that the
takes by mortality requested for authorization are for the maximum
number of instances mortality or serious injury could occur, as in the
case of ship shock trials and vessel strikes.
Table 2, table 3, and table 4 summarize the maximum annual and 7-
year total amount and type of Level A harassment and Level B harassment
that NMFS concurs is reasonably expected to occur by species and stock
for Navy training activities, Navy testing activities, and Coast Guard
training activities, respectively.
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Estimated Take From Sonar and Other Transducers
Table 5, table 6, and table 7 provide estimated effects from sonar
and other transducers, including the comparative amounts of TTS and
behavioral disturbance for each species and stock annually, noting that
if a modeled marine mammal was ``taken'' through exposure to both TTS
and behavioral disturbance in the model, it was recorded as a TTS. Of
note, a higher proportion of the takes by Level B harassment of
mysticetes include the potential for TTS (as compared to other taxa and
prior rules) due to a combination of the fact that mysticetes are
relatively less sensitive to behavioral disturbance and the number of
auditory impacts from sonar (both TTS and AUD INJ) have increased for
some species since the Phase III analysis (84 FR 70712, December 23,
2019) largely due to changes in how avoidance was modeled; for some
stocks, changes in densities in areas that overlap activities have also
contributed to increased or decreased impacts compared to those modeled
in Phase III.
Additionally, although the Navy proposes to use substantially fewer
hours of hull-mounted sonars in this action compared to the Phase III
analysis, the updated high-frequency (HF) cetacean criteria reflect
greater susceptibility to auditory effects at low and mid-frequencies
than previously analyzed. Consequently, the predicted auditory effects
due to sources under 10 kHz, including but not limited to MF1 hull-
mounted sonar and other anti-submarine warfare sonars, are
substantially higher for this auditory group than in prior analyses of
the same activities. Thus, for activities with sonars, some modeled
exposures that would previously have been categorized as significant
behavioral responses may now instead be counted as auditory effects
(TTS and AUD INJ). Similarly, the updated HF cetacean criteria reflect
greater susceptibility to auditory effects at low and mid-frequencies
in impulsive sounds. For VHF cetaceans, susceptibility to auditory
effects has not changed substantially since the prior analysis.
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Estimated Take From Air Guns and Pile Driving
Table 8 provides estimated effects from air guns, including the
comparative amounts of TTS and behavioral disturbance for each species
and stock annually, noting that if a modeled marine mammal was
``taken'' through exposure to both TTS and behavioral disturbance in
the model, it was recorded as a TTS.
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Table 9 provides the estimated effects from pile driving and
extraction, including the comparative amounts of TTS and behavioral
disturbance for each species and stock annually, noting that if a
modeled marine mammal was
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``taken'' through exposure to both TTS and behavioral disturbance in
the model, it was recorded as a TTS.
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Estimated Take From Explosives
Table 10 provides estimated effects from explosives during Navy
training activities and table 11 provides estimated effects from
explosives including small ship shock trials from Navy testing
activities. Table 12 provides estimated effects from small ship shock
trials over a maximum year (two events) of Navy testing activities,
which is a subset of the information included in table 11. Table 13
provides estimated effects from explosives during Coast Guard training
activities.
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Estimated Take From Vessel Strike by Serious Injury or Mortality
Vessel strikes from commercial, recreational, and military vessels
are known to affect large whales and have resulted in serious injury
and fatalities to cetaceans (Abramson et al., 2011; Berman-Kowalewski
et al., 2010a; Calambokidis, 2012; Douglas et al., 2008; Laggner, 2009;
Lammers et al., 2003; Van der Hoop et al., 2013; Van der Hoop et al.,
2012). Records of vessel strikes of large whales date back to the early
17th century, and the worldwide number of vessel strikes of large
whales 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; Greig et al., 2020;
Guilpin et al., 2020; Keen et al., 2019; Lemon et al., 2006; Lusseau,
2003; Lusseau, 2006; Magalhaes et al., 2002; Nowacek et al., 2001;
Redfern et al., 2020; Richter et al., 2003; Scheidat et al., 2004;
Simmonds, 2005; Szesciorka et al., 2019; 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). 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 Action Proponents are conducting military
readiness activities using active sonar or 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 strikes (Nowacek
et al., 2004). These species are primarily large, slow-moving whales.
There are 9 species (15 stocks) of large whales that are known to occur
within the AFTT Study Area (table 1): blue whale, Bryde's whale, fin
whale, humpback whale, minke whale, NARW, Rice's whale, sei whale, and
sperm whale.
Some researchers have suggested that 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 vessel to detect a
marine mammal and avoid a collision depends on a variety of factors,
including environmental conditions, vessel 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. Large whales also do not have to be
at the water's surface to be struck. Silber et al. (2010) found that
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:
Military vessels 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 and
are certified to stand watch only after demonstrating competency in all
necessary skills. While on watch, personnel employ visual search and
reporting procedures in accordance with the U.S. Navy Lookout Training
Handbook, the Coast Guard's Shipboard Lookout Manual, or civilian
equivalent.
The bridges of many military vessels are positioned closer
to the bow, offering better visibility ahead of the vessel (compared to
a commercial merchant vessel);
Military readiness activities often involve aircraft
(which can serve as part of the Lookout team), that can more readily
detect cetaceans in the vicinity of a vessel or ahead of a vessel's
present course, often before crew on the vessel would be able to detect
them;
Military vessels are generally more maneuverable than
commercial merchant vessels, and are therefore capable of changing
course more quickly in the event cetaceans are spotted in the vessel's
path;
Military vessels operate at the slowest speed practical
consistent with operational requirements. While minimum speed is
intended as a fuel conservation measure particular to a certain ship
class, secondary benefits include a better ability to detect and avoid
objects in the water, including marine mammals;
Military ships often operate within a defined area for a
period of time, in contrast to point-to-point commercial shipping over
greater distances;
The crew size on military vessels is generally larger than
merchant vessels, allowing for stationing more trained Lookouts on the
bridge. At all times when the Action Proponents' 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.
Some events may have additional personnel (beyond the minimum number of
required Lookouts) who are already standing watch in or on the platform
conducting the event or additional participating platforms and would
have eyes on the water for all or part of an event. These additional
personnel serve as members of the Lookout team; and
When submerged, submarines are generally slow moving (to
avoid detection); as a result, marine mammals at depth with a submarine
are likely able to avoid collision with the submarine. When a submarine
is transiting on the surface, the Navy posts Lookouts serving the same
function as they do on surface vessels.
Vessel strike to marine mammals is not associated with any specific
military readiness activity. Rather, vessel strike is a limited and
sporadic, but possible, accidental result of military vessel movement
within the AFTT Study Area or while in transit.
Prior to 2009, there is limited information on vessel strikes from
military readiness activities in the AFTT Study Area. One known
incident of vessel strike in the AFTT Study Area occurred in 2001, when
a 505 ft (154 m) Navy vessel struck and killed a sperm whale 17.4 nmi
(32.2 km) south of Puerto Rico (Jensen and Silber, 2004). Of note, at
the time of the strike, the Navy still used the Vieques Naval Training
Range; activities in this area ceased in 2003, and since then, vessel
traffic has significantly decreased, and
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there are currently no plans to increase activity in that area. A
second known incident of vessel strike occurred in VACAPES on May 15,
2005, when a Navy vessel was involved in a strike with ``reasonable
potential'' to have been a sperm whale.
Since 2009, there have been six recorded vessel strikes of large
whales by the Action Proponents in the AFTT Study Area: three by the
Navy and three by the Coast Guard. The Navy struck one whale in 2011
(species unknown), two whales in 2012 (species unknown), and has not
struck a large whale in the AFTT Study Area since 2012. All strikes
during this timeframe occurred in the VACAPES OPAREA: one strike in the
VACAPES Range Complex in 2011, one strike in the VACAPES Range Complex
in 2012, and one strike in the Lower Chesapeake Bay in 2012. The Coast
Guard struck two whales in 2009 (both reported as NARW), and one whale
in May 2024 (species unknown), all in the mid-Atlantic. On December 14,
2009, an 87-ft (26.5-m) Coast Guard patrol boat traveling at a speed of
9.2 kn (17 km/hr) struck two whales (reported as NARW) at the same time
near Cape Henry, Virginia, and observed the animals swimming away
without apparent injuries, though it is important to note that not all
injuries are evident when a whale is struck and the fate of these two
NARW is unknown. It is also important to note that not all whale
strikes result in mortality; however, given the potential for non-
visible injuries, NMFS conservatively assumes that these strikes
resulted in mortality of both whales.
In light of the key differences between the operation of military
and non-military vessels discussed above, it is highly unlikely that a
military vessel would strike any type of marine mammal without
detecting it. Specifically, Lookouts posted on or near the ship's bow
can visually detect a strike in the absence of other indications that a
strike has occurred. The Action Proponents' internal procedures and
mitigation requirements include reporting of any vessel strikes of
marine mammals, and the Action Proponents' discipline, extensive
training (not only for detecting marine mammals, but for detecting and
reporting any potential navigational obstruction), and strict chain of
command give NMFS a high level of confidence that all strikes are
reported. Accordingly, NMFS is confident that the Navy and Coast
Guard's reported strikes are accurate and appropriate for use in the
analysis.
Neither NMFS, nor the Action Proponents anticipate vessel strike of
dolphins, small whales (not including large whale calves), porpoises,
or pinnipeds from the specified activity. For as long as records have
been kept, neither the Navy nor the Coast Guard have any record of any
small whales or pinnipeds being struck by a vessel as a result of
military readiness activities. Over the same time period, NMFS, the
Navy, and the Coast Guard have only one record of a dolphin being
struck by a vessel as a result of Navy or Coast Guard activities. The
dolphin was accidentally struck by a Navy small boat in fall 2021 in
Saint Andrew's Pass, Florida. Except for the single reported strike of
a dolphin in 2021, NMFS has never received any reports from other LOA
or Incidental Harassment Authorization holders indicating that these
species have been struck by vessels. Further, the majority of the
Action Proponents' activities involving faster-moving vessels (that
could be considered more likely to hit a marine mammal) are located in
offshore areas where smaller delphinid, porpoise, and pinniped
densities are lower.
In order to account for the accidental nature of vessel strike to
large whales in general, and the potential risk from vessel movement
within the AFTT Study Area within the 7-year period of this
authorization, the Action Proponents requested incidental takes based
on probabilities derived from a Poisson distribution. A Poisson
distribution is often used to describe random occurrences when the
probability of an occurrence is small. Count data, such as cetacean
sighting data, or in this case strike data, are often described as a
Poisson or over-dispersed Poisson distribution. The Poisson
distribution was calculated using vessel strike data between 2009 and
2024 in the AFTT Study Area, historical at-sea days in the AFTT Study
Area for the Navy and the Coast Guard (described in detail in section 6
of the application) and estimated potential at-sea days for both Action
Proponents during the 7-year period from 2025 to 2032 covered by the
requested regulations. The Navy evaluated data beginning in 2009, as
that year was the start of the Navy's Marine Species Awareness Training
and adoption of additional mitigation measures to address vessel
strike, which will remain in place along with additional and modified
mitigation measures during the 7 years of this rulemaking. Navy vessel
strike data only accounts for vessels larger than 65 ft (19.8 m) and
does not include unmanned surface vehicles (USVs) or unmanned
underwater vehicles (UUVs) as the Navy does not yet have data on their
use in the AFTT Study Area. The Poisson vessel strike calculations do
not include any specific number of at-sea days for USVs. Historically,
the USVs used in the AFTT Study Area were equivalent to small boats.
While it is anticipated that larger USVs will begin testing in the AFTT
Study Area during the 7-year period, it was assessed that the addition
of any at-sea days associated with the limited number of medium or
large USVs being tested in AFTT would not be large enough to change the
results of the analysis. In addition, there is no historical strike
data for USVs. The analysis for the period of 2025 to 2032 is described
in detail below and in section 6.3.2 (Probability of Vessel Strike of
Large Whale Species) of the application.
Between 2009 and early 2024, there were a total of 42,748 Navy at-
sea days and 26,756 Coast Guard at-sea days in the AFTT Study Area.
During that same time, there were three Navy vessel strikes of large
whales and three Coast Guard vessel strikes of large whales. From 2025
through 2032, the Navy anticipates 18,702 at-sea days, and the Coast
Guard anticipates 11,706 at-sea days.
To calculate a vessel strike rate for each Action Proponent for the
period of 2009 through 2024, the Action Proponents used the respective
number of past vessel strikes of large whales and the respective number
of at-sea days. Navy at-sea days (for vessels greater than 65 ft (19.8
m)) from 2009 through 2024 was estimated to be 42,748 days. Dividing
the 3 known Navy strikes during that period by the at-sea days (i.e., 3
strikes/42,748 at-sea days) results in a strike rate of 0.000070
strikes per at-sea day. Coast Guard at-sea days (for vessels greater
than 65 ft (19.8 m)) from 2009 through 2024 was estimated to be 26,756
days. Dividing the 3 known Coast Guard strikes during that period by
the at-sea days (i.e., 3 strikes/26,756 at-sea days) results in a
strike rate of 0.000112 strikes per day.
Based on the average annual at-sea days from 2009 to early 2024,
the Action Proponents estimated that 18,702 Navy and 11,706 Coast Guard
at-sea days would occur over the 7-year period associated with the
requested authorization. Given a strike rate of 0.000070 Navy strikes
per at-sea day, and 0.000112 Coast Guard strikes per at-sea day, the
predicted number of vessel strikes over a 7-year period would be 1.31
strikes by the Navy and 1.31 strikes by the Coast Guard.
Using this predicted number of strikes, the Poisson distribution
predicted the probabilities of a specific number of strikes (n = 0, 1,
2, etc.) from 2025 through 2032. The probability
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analysis concluded that, for each Action Proponent, there is a 27
percent chance that zero whales would be struck by the Action
Proponents' vessels over the 7-year period, and a 35, 23, 10, and 4
percent chance that one, two, three, or four whales, respectively,
would be struck by each Action Proponent over the 7-year period (with a
73 percent chance that at least one whale would be struck by each
Action Proponent over the entire 7-year period). Based on this
analysis, the Navy requested authorization to take three large whales
by serious injury or mortality by vessel strike incidental to Navy
training and testing activities, and the Coast Guard is requesting
authorization to take three large whales by serious injury or mortality
by vessel strike incidental to Coast Guard training activities. NMFS
concurs that take by serious injury or mortality by vessel strike of up
to three large whales by each Action Proponent (six whales total) could
occur over the 7-year regulations and, based on the information
provided earlier in this section, NMFS concurs with the Action
Proponents' assessment and recognizes the potential for incidental take
by vessel strike of large whales only (i.e., no dolphins, small whales
(not including large whale calves), porpoises, or pinnipeds) over the
course of the 7-year regulations from military readiness activities.
While the Poisson distribution allows the Action Proponents and
NMFS to determine the likelihood of vessel strike of all large whales,
it does not indicate the likelihood of each strike occurring to a
particular species or stock. As described above, the Action Proponents
have not always been able to identify the species of large whale struck
during previous known vessel strikes. Therefore, the Action Proponents
requested authorization for take by serious injury or mortality by
vessel strike of any combination of the following stocks in the AFTT
Study Area, with no more than two takes total from any of the following
single stocks: humpback whale (Gulf of Maine stock), fin whale (Western
North Atlantic stock), sei whale (Nova Scotia stock), minke whale
(Canadian East Coast stock), blue whale (Western North Atlantic stock),
and sperm whale (North Atlantic stock).
After concurring that take of up to six large whales could occur
(three takes by each Action Proponent), and in consideration of the
Navy's request, NMFS considered which species could be among the six
large whales struck. NMFS conducted an analysis that considered several
factors: (1) the relative likelihood of striking one stock versus
another based on available strike data from all vessel types as denoted
in the SARs; (2) whether each Action Proponent has ever struck an
individual from a particular species or stock in the AFTT Study Area,
and if so, how many times; and (3) whether implementation of the
proposed mitigation measures (i.e., specific measures to reduce the
potential for vessel strike) would be expected to successfully prevent
vessel strikes of certain species or stocks (noting that, for all
stocks, activity-based mitigation would reduce the potential of vessel
strike).
To address number (1) above, NMFS compiled information from the
SARs (Hayes et al., 2024) on detected annual rates of large whale M/SI
from vessel strike (table 14). The annual rates of large whale serious
injury or mortality from vessel strike reported in the SARs help inform
the relative susceptibility of large whale species to vessel strike in
AFTT Study Area as recorded systematically over the 5-year period used
for the SARs. We summed the annual rates of serious injury or mortality
from vessel strikes as reported in the SARs and then divided each
species' annual rate by this sum to get the percentage of total annual
strikes for each species/stock (table 14).
To inform the likelihood of a single Action Proponent striking a
particular species of large whale, we multiplied the percent of total
annual strikes for a given species in table 14 by the total percent
likelihood of a single Action Proponent striking at least one whale
(i.e., 73 percent, as described by the probability analysis above). We
also calculated the percent likelihood of a single Action Proponent
striking a particular species of large whale two or three times by
squaring or cubing, respectively, the value estimated for the
probability of striking a particular species of whale once (i.e., to
calculate the probability of an event occurring twice, multiply the
probability of the first event by the second). The results of these
calculations are reflected in the last two columns of table 14. We note
that these probabilities vary from year to year as the average annual
mortality changes depending on the specific range of time considered;
however, over the years and through updated data in the SARs, stocks
tend to consistently maintain a relatively higher or relatively lower
likelihood of being struck.
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The percent likelihood calculated (as described above) are then
considered in combination with the information indicating the known
species that the Navy or Coast Guard has struck in the AFTT Study Area
since 2000 (table 15). We note that for the lethal take of species
specifically denoted in table 15 below, most of those struck by the
Navy or Coast Guard remained unidentified. However, given the
information on known stocks struck, the analysis below remains
appropriate.
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Accordingly, stocks that have no record of ever having been struck
by any vessel are considered to have a zero percent likelihood of being
struck by the Navy in the 7-year period of the rule. While the Western
North Atlantic stock of blue whales, Northern Gulf of America stock of
Rice's whale, Nova Scotia stock of sei whales, and North Atlantic stock
of sperm whales have a reported annual rate of M/SI from vessel strike
of zero, each of these stocks have records of strikes prior to the
period reported in the SAR (Hayes et al. 2024). There is record of a
vessel strike in 1996 of a Western North Atlantic blue whale (Hayes et
al. 2024), two records of vessel strike of Rice's whale (one in 2009
and one in 2019), several records of vessel strikes in the 1990s and
early 2000s of North Atlantic sperm whales, and a record of a probable
sperm whale (Northern Gulf of America stock) strike in 1990. For the
Nova Scotia stock of sei whale, several sei whale strandings during the
time period analyzed for the SAR (i.e., 2017-2021) had an undetermined
cause of death (Garron, 2022), and M/SI by vessel strike for sei whales
along the U.S. East Coast were a more common occurrence in previous SAR
5-year periods (i.e., four from 2012 to 2016, three from 2007 to 2011,
and two from 2002 to 2006). Therefore, NMFS included each of these
stocks for further analysis, and considered the historical strikes, but
lack of recent strikes to inform the relative likelihood that the Navy
or Coast Guard would strike these stocks.
While Bryde's whales in the Atlantic are not a NMFS-managed stock,
the low number of estimated takes by harassment (11 takes by Level B
harassment) indicates very low overlap of this stock with the Action
Proponents' activities. As such, and given that there are no records of
either Action Proponent having struck Bryde's whale in the Atlantic in
the past, NMFS neither anticipates, nor proposes to authorize, serious
injury or mortality by vessel strike of Bryde's whale.
To address number (2) above (whether each Action Proponent has ever
struck an individual from a particular species or stock in the AFTT
Study Area, and if so, how many times), the percent likelihoods of a
certain number of strikes of each stock are then considered in
combination with the information indicating the species that the Action
Proponents have definitively struck in the AFTT Study Area since 2009.
As noted above, since 2009, the U.S. Navy and Coast Guard have each
struck three whales in the AFTT Study Area. The Navy struck one
unidentified species in June 2011, one unidentified species (thought to
likely be a humpback) in February 2012, and one unidentified species in
October 2012. The USCG struck two whales (reported as NARW) in December
2009, and one unidentified large whale (thought to likely be a
humpback) in 2024.
Stocks that have never been struck by the Navy, have rarely been
struck by other vessels, and have a low percent likelihood based on the
historical vessel strike calculation are also considered to have a zero
percent likelihood to be struck by the Navy during the 7-year rule. As
noted in table 15, in 2001, the Navy struck an unidentified whale in
the Gulf of America, and given the stocks that occur there, this strike
was of either a sperm whale or Rice's whale. Given the relative
abundance of these two stocks, NMFS expects that this strike was likely
of a sperm whale (Northern Gulf of America stock). Therefore, this step
in the analysis rules out take by vessel strike of blue whale and
Rice's whale. Even if the 2001 strike had been of a Rice's whale,
consideration of the proposed geographic mitigation for Rice's whale
(see Mitigation Measures section below) and the low stock abundance
further supports the conclusion that vessel strike of Rice's whale is
unlikely. This leaves the following stocks for further analysis: fin
whale (Western North Atlantic stock), humpback whale (Gulf of Maine
stock), minke whale (Canadian Eastern Coastal stock), NARW (Western
stock), sei whale (Nova Scotia stock), and sperm whale (North Atlantic
and Northern Gulf of America stocks).
Based on the information summarized in table 14, and the fact that
there is potential for up to six large whales to be struck over the 7-
year duration of this rulemaking, NMFS anticipates that each Action
Proponent could strike one of each of the following stocks (two total
per stock across both Action Proponents): fin whales (Western North
Atlantic stock), minke whales (Canadian Eastern Coastal stock), sei
whales (Nova Scotia stock), and sperm whales (North Atlantic stock).
NMFS also anticipates that the Navy may strike up to one sperm whale
(Northern Gulf of America stock) given the 2001 likely sperm whale
strike. Given the already lower likelihood of striking this stock given
the relatively lower vessel activity in the Gulf of America portion of
the AFTT Study Area, and the relatively lower Coast Guard vessel
traffic compared to Navy vessel traffic, NMFS neither anticipates, nor
proposes to authorize, a Coast Guard strike of this stock. NMFS
anticipates that each Action Proponent could strike up to two humpback
whales (Gulf of Maine stock) given the
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higher relative strike likelihood indicated in table 14, and the Action
Proponents' conclusion that several previous Navy and Coast Guard
strikes of unidentified species were likely humpback whales.
Following the conclusion for the stocks above, NARW is the only
remaining stock. NARW are known to be particularly susceptible to
vessel strike, and vessel strike is one of the greatest threats to this
stock. NMFS' quantitative analysis (table 14) indicates a 15 percent
likelihood of one strike of NARW over the 7-year duration of this rule.
However, for the reasons described below, NMFS does not anticipate
vessel strike of NARW by either Action Proponent. As stated previously,
in 2009, the Coast Guard struck two whales (reported as NARW). Since
2009, the Navy has had no known strikes of NARW, and it has been
implementing extensive mitigation measures to avoid vessel strike of
NARW. The lack of known strikes of NARWs indicates that the mitigation
used by the Navy since 2009 and included here for the Action Proponents
has likely been successful. Given that the Navy will continue to
implement this mitigation for NARW, and the Coast Guard will continue/
begin implementing mitigation also, (e.g., funding of and communication
with sightings systems, awareness of slow zones and dynamic management
areas for NARW) we neither anticipate nor authorize take by serious
injury or mortality by vessel strike of NARW. Please see the Mitigation
Measures section of this rulemaking and section 11 of the application
for additional detail.
In conclusion, although it is generally unlikely that any whales
will be struck in a year, based on the information and analysis above,
NMFS anticipates that no more than six takes of large whales by serious
injury or mortality could occur over the 7-year period of the rule,
with no more than three by each Action Proponent. Of those six whales
over the 7 years: no more than four may come from the Gulf of Maine
stock of humpback whale; no more than two may come from the Western
North Atlantic stock of fin whale, the Canadian East Coast stock of
minke whale, the Nova Scotia stock of sei whale, and the North Atlantic
stock of sperm whale; and no more than one strike by the Navy may come
from the Northern Gulf of America stock of sperm whale. Accordingly,
NMFS has evaluated under the negligible impact standard the M/SI of
0.14, 0.29, or 0.57 whales annually from each of these species or
stocks (i.e., 1, 2, or 4 takes, respectively, divided by 7 years to get
the annual value), along with the expected incidental takes by
harassment.
Summary of Requested Take From Military Readiness Activities
Table 16 and table 17 summarize the authorized take by Level B
harassment, Level A harassment, or mortality and by effect type,
respectively.
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BILLING CODE 3510-22-C
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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. For additional
discussion of NMFS' interpretation of the least practicable adverse
impact standard, see the Mitigation Measures section of the Gulf of
Alaska Study Area final rule (88 FR 604, January 4, 2023).
The mitigation measures described in the following section were
proposed by the Action Proponents in their adequate and complete
application or are the result of subsequent coordination between NMFS
and the Action Proponent. Pursuant to the 2004 NDAA, NMFS coordinated
with the Action Proponents, and the Action Proponents have agreed that
all of the mitigation measures are practicable. NMFS has fully reviewed
the specified activities and the mitigation measures included in the
application to determine if the mitigation measures will result in the
least practicable adverse impact on marine mammals and their habitat,
as required by the MMPA, and has determined the measures are
appropriate. NMFS describes these below as mitigation requirements and
has included them in the final regulations.
As noted in the Changes from the Proposed to Final Rule section,
NMFS has added new mitigation requirements and clarified a few others
in this final rule. These changes are described in detail in the
sections below. Besides these changes, the required measures remain the
same as those described in the proposed rule.
Implementation of Least Practicable Adverse Impact Standard
Here, we discuss how we determine whether a measure or set of
measures meets the ``least practicable adverse impact'' standard. Our
separate analysis of whether the take anticipated to result from the
Action Proponents' activities meets the ``negligible impact'' standard
appears in the Analysis and Negligible Impact Determination section.
Our evaluation of potential mitigation measures includes
consideration of two primary factors:
1. The manner in which, and the degree to which, implementation of
the potential measure(s) is expected to reduce adverse impacts to
marine mammal species or stocks, their habitat, or their availability
for subsistence uses (where relevant). This analysis considers such
things as the nature of the potential adverse impact (e.g., likelihood,
scope, and range), the likelihood that the measure will be effective if
implemented, and the likelihood of successful implementation; and
2. The practicability of the measure(s) for applicant
implementation. Practicability of implementation may consider such
things as cost, impact on activities, 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.
While the language of the least practicable adverse impact standard
calls for minimizing impacts to affected species or stocks, we
recognize that the reduction of impacts to those species or stocks
accrues through the application of mitigation measures that limit
impacts to individual animals. Accordingly, NMFS' analysis focuses on
measures that are designed to avoid or minimize impacts on individual
marine mammals that are more likely to increase the probability or
severity of population-level effects.
While direct evidence of impacts to species or stocks from a
specified activity is rarely available, and additional study is still
needed to understand how specific disturbance events affect the fitness
of individuals of certain species, there have been improvements in
understanding the process by which disturbance effects are translated
to the population. With recent scientific advancements (both marine
mammal energetic research and the development of energetic frameworks),
the relative likelihood or degree of impacts on species or stocks may
often be inferred given a detailed understanding of the activity, the
environment, and the affected species or stocks--and the best available
science has been used here. This same information is used in the
development of mitigation measures and helps us understand how
mitigation measures contribute to lessening effects (or the risk
thereof) to species or stocks. We also acknowledge that there is always
the potential that new information, or a new recommendation, could
become available in the future and necessitate reevaluation of
mitigation measures (which may be addressed through adaptive
management) to see if further reductions of population impacts are
possible and practicable.
In the evaluation of specific measures, the details of the
specified activity will necessarily inform each of the two primary
factors discussed above (expected reduction of impacts and
practicability) and are carefully considered to determine the types of
mitigation that are appropriate under the least practicable adverse
impact standard. Analysis of how a potential mitigation measure may
reduce adverse impacts on a marine mammal stock or species,
consideration of personnel safety, practicality of implementation, and
consideration of the impact on effectiveness of military readiness
activities are not issues that can be meaningfully evaluated through a
yes/no lens. The manner in which, and the degree to which,
implementation of a measure is expected to reduce impacts, as well as
its practicability in terms of these considerations, can vary widely.
For example, a time/area restriction could be of very high value for
decreasing population-level impacts (e.g., avoiding disturbance of
feeding females in an area of established biological importance) or it
could be of lower value (e.g., decreased disturbance in an area of high
productivity but of less biological importance). Regarding
practicability, a measure might involve restrictions in an area or time
that impede the Navy's ability to certify a strike group (higher impact
on mission effectiveness), or it could mean delaying a small in-port
training event by 30 minutes to avoid exposure of a marine mammal to
injurious levels of sound (lower impact). A responsible evaluation of
``least practicable adverse impact'' will consider the factors along
these realistic scales. Accordingly, the greater the likelihood that a
measure will contribute to reducing the probability or severity of
adverse impacts to the species or stock or its habitat, the greater the
weight that measure is given when considered in combination with
practicability to determine the appropriateness of the mitigation
measure, and vice versa. We discuss consideration of these factors in
greater detail below.
[[Page 50605]]
1. Reduction of Adverse Impacts to Marine Mammal Species or Stocks and
Their Habitat
The emphasis given to a measure's ability to reduce the impacts on
a species or stock considers the degree, likelihood, and context of the
anticipated reduction of impacts to individuals (and how many
individuals) as well as the status of the species or stock.
The ultimate impact on any individual from a disturbance event
(which informs the likelihood of adverse species- or stock-level
effects) is dependent on the circumstances and associated contextual
factors, such as duration of exposure to stressors. Though any proposed
mitigation needs to be evaluated in the context of the specific
activity and the species or stocks affected, measures with the
following types of effects have greater value in reducing the
likelihood or severity of adverse species- or stock-level impacts:
avoiding or minimizing injury or mortality; limiting interruption of
known feeding, breeding, mother/young, or resting behaviors; minimizing
the abandonment of important habitat (temporally and spatially);
minimizing the number of individuals subjected to these types of
disruptions; and limiting degradation of habitat. Mitigating these
types of effects is intended to reduce the likelihood that the activity
will result in energetic or other types of impacts that are more likely
to result in reduced reproductive success or survivorship. It is also
important to consider the degree of impacts that is expected in the
absence of mitigation in order to assess the added value of any
potential measures. Finally, because the least practicable adverse
impact standard gives NMFS discretion to weigh a variety of factors
when determining appropriate mitigation measures and because the focus
of the standard is on reducing impacts at the species or stock level,
the least practicable adverse impact standard does not compel
mitigation for every kind of take, or every individual taken, if that
mitigation is unlikely to meaningfully contribute to the reduction of
adverse impacts on the species or stock and its habitat, even when
practicable for implementation by the applicant.
The status of the species or stock is also relevant in evaluating
the appropriateness of potential mitigation measures in the context of
least practicable adverse impact. The following are examples of factors
that may (either alone, or in combination) result in greater emphasis
on the importance of a mitigation measure in reducing impacts on a
species or stock: the stock is known to be decreasing or status is
unknown, but believed to be declining; the known annual mortality (from
any source) is approaching or exceeding the PBR level, as defined in
section 3(20) of the MMPA (16 U.S.C. 1362); the affected species or
stock is a small, resident population; or the stock is involved in a
UME or has other known vulnerabilities, such as recovering from an oil
spill.
Habitat mitigation, particularly as it relates to rookeries, mating
grounds, and areas of similar significance, is also relevant to
achieving the standard and can include measures such as reducing
impacts of the activity on known prey utilized in the activity area or
reducing impacts on physical habitat. As with species- or stock-related
mitigation, the emphasis given to a measure's ability to reduce impacts
on a species or stock's habitat considers the degree, likelihood, and
context of the anticipated reduction of impacts to habitat. Because
habitat value is informed by marine mammal presence and use, in some
cases there may be overlap in measures for the species or stock and for
use of habitat.
We consider available information indicating the likelihood of any
measure to accomplish its objective. If evidence shows that a measure
has not typically been effective nor successful, then either that
measure should be modified or the potential value of the measure to
reduce effects should be lowered.
2. Practicability
Factors considered may include cost, impact on activities, and, in
the case of a military readiness activity, will include personnel
safety, practicality of implementation, and impact on the effectiveness
of the military readiness activity (see MMPA section 101(a)(5)(A)(ii)).
Assessment of Mitigation Measures for the AFTT Study Area
NMFS has fully reviewed the specified activities and the mitigation
measures included in the application and the 2025 AFTT Supplemental
EIS/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 Action Proponents in the development of their
initially proposed measures, which are informed by years of
implementation and monitoring. A complete discussion of the Action
Proponents' evaluation process used to develop, assess, and select
mitigation measures, which was informed by input from NMFS, can be
found in chapter 5 (Mitigation) of the 2025 AFTT Supplemental EIS/OEIS.
The process described in chapter 5 (Mitigation) and appendix A
(Activity Descriptions) of the 2025 AFTT Supplemental EIS/OEIS robustly
supported NMFS' independent evaluation of whether the mitigation
measures would meet the least practicable adverse impact standard. The
Action Proponents are required to implement the mitigation measures
identified in this rule for the full 7 years to avoid or reduce
potential impacts from acoustic, explosive, and physical disturbance
and 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.
Since publication of the proposed rule, and in consideration of
public comments received, additional mitigation requirements have been
added that will further reduce the likelihood and/or severity of
adverse impacts on marine mammal species and their habitat. Pursuant to
the 2004 NDAA, NMFS coordinated with the Action Proponents, and the
Action Proponents have agreed the additional mitigation measures are
practicable for implementation, as previously described in the Changes
from the Proposed Rule to the Final Rule section. Below we describe the
added measures that the Action Proponents will implement and explain
the manner in which they are expected to reduce the likelihood or
severity of adverse impacts on marine mammals and their habitats.
Overall, the Action Proponents have agreed to mitigation measures
that would reduce the probability and/or severity of impacts expected
to result from acute exposure to acoustic sources or explosives, vessel
strike, and impacts to marine mammal habitat. Specifically, the Action
Proponents must use a combination of delayed starts, powerdowns, and
shutdowns to avoid mortality or serious injury, minimize the likelihood
or severity of AUD INJ or non-auditory injury, and reduce instances of
TTS or more severe behavioral disturbance caused by acoustic sources or
explosives. The Action Proponents must also implement
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multiple time/area restrictions that will reduce take of marine mammals
in areas or at times where they are known to engage in important
behaviors, such as calving, where the disruption of those behaviors
would have a higher probability of resulting in impacts on reproduction
or survival of individuals that could lead to population-level impacts.
The Action Proponents assessed the practicability of these measures
in the context of personnel safety, practicality of implementation, and
their impacts on the Action Proponents' ability to meet their
congressionally mandated requirements and found that the measures are
supportable. NMFS has independently evaluated the measures the Action
Proponents proposed in the manner described earlier in this section
(i.e., in consideration of their ability to reduce adverse impacts on
marine mammal species and their habitat and their practicability for
implementation). We have determined that the measures will
significantly reduce impacts on the affected marine mammal species and
stocks and their habitat and, further, be practicable for
implementation by the Action Proponents. We have determined that the
mitigation measures ensure that the Action Proponents' activities will
have the least practicable adverse impact on the species or stocks and
their habitat.
The Action Proponents also evaluated numerous measures in the 2025
AFTT Supplemental EIS/OEIS that were not included in the application,
and NMFS independently reviewed and concurs with the Action Proponents'
analysis that their inclusion was not appropriate under the least
practicable adverse impact standard based on our assessment. The Action
Proponents considered these additional potential mitigation measures in
the context of the potential benefits to marine mammals and whether
they are practical or impractical.
Section 5.9 (Measures Considered but Eliminated) of chapter 5
(Mitigation) of the 2025 AFTT Supplemental EIS/OEIS, 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. These recommendations generally fall into three categories,
discussed below: (1) reduction of activity; (2) activity-based
operational measures; and (3) time/area limitations.
As described in section 5.9 (Measures Considered but Eliminated) of
the 2025 AFTT Supplemental EIS/OEIS, the Action Proponents considered
reducing the overall amount of training, reducing explosive use,
modifying sound sources, completely replacing live training with
computer simulation, and including time of day restrictions. Many of
these mitigation measures could potentially reduce the number of marine
mammals taken via direct reduction of the activities or amount of sound
energy put in the water. However, as described in chapter 5
(Mitigation) of the 2025 AFTT Supplemental EIS/OEIS, the Action
Proponents need to train in the conditions in which they fight--and
these types of modifications fundamentally change the activity in a
manner that would not support the purpose and need for the training
(i.e., are entirely impracticable) and therefore are not considered
further. NMFS finds the Action Proponents' explanation of why adoption
of these recommendations would unacceptably undermine the purpose of
the training persuasive. After independent review, NMFS finds the
Action Proponents' judgment on the impacts of these potential
mitigation measures to personnel safety, practicality of
implementation, and the effectiveness of training persuasive, and for
these reasons, NMFS finds that these measures do not meet the least
practicable adverse impact standard because they are not practicable.
In chapter 5 (Mitigation) of the 2025 AFTT Supplemental EIS/OEIS,
the Action Proponents evaluated additional potential activity-based
mitigation measures, including increased mitigation zones, ramp-up
measures, additional passive acoustic and visual monitoring, and
decreased vessel speeds. Some of these measures have 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 Action Proponents' analysis,
the measures would have significant direct negative effects on mission
effectiveness and are considered impracticable (see chapter 5 of the
2025 AFTT Supplemental EIS/OEIS). NMFS independently reviewed the
Action Proponents' evaluation and concurs with this assessment, which
supports NMFS' findings that the impracticability of this additional
mitigation would greatly outweigh any potential minor reduction in
marine mammal impacts that might result; therefore, these additional
mitigation measures are not warranted.
Last, chapter 5 (Mitigation) of the 2025 AFTT Supplemental EIS/OEIS
also describes a comprehensive analysis of potential geographic
mitigation that includes consideration of both a 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 an area for training, considering
proximity to training ranges and emergency landing fields and other
issues). In some cases, potential benefits to marine mammals were non-
existent, while in others the consequences on mission effectiveness
were too great.
NMFS has reviewed the Action Proponents' analysis in chapter 5
(Mitigation) and appendix A (Activity Descriptions) of the 2025 AFTT
Supplemental EIS/OEIS, which consider the same factors that NMFS
considers to satisfy the least practicable adverse impact standard, and
concurs with the analysis and conclusions. Therefore, NMFS is not
requiring any of the measures that the Action Proponents ruled out in
the 2025 AFTT Supplemental EIS/OEIS. Below are the mitigation measures
that NMFS has determined would ensure the least practicable adverse
impact on all affected species and their habitat, including the
specific considerations for military readiness activities. Table 18
describes the information designed to aid Lookouts and other applicable
personnel with their observation, environmental compliance, and
reporting responsibilities. The following sections describe the
mitigation measures that must be implemented in association with the
activities analyzed in this document. The mitigation measures are
organized into two categories: (1) activity-based mitigation; and (2)
geographic mitigation areas.
Of note, according to the U.S. Navy, consistent with customary
international law, when a foreign military vessel participates in a
U.S. Navy exercise within the U.S. territorial sea (i.e., 0 to 12 nmi
(0 to 22.2 km) from shore), the U.S. Navy will request that the foreign
vessel follow the U.S. Navy's mitigation measures for that particular
event. When a foreign military vessel participates in a U.S. Navy
exercise beyond the U.S. territorial sea but within the U.S. EEZ, the
U.S. Navy will encourage the foreign vessel to follow the U.S. Navy's
mitigation measures for that particular event (Navy 2022a; Navy 2022b).
In either scenario (i.e., both within and beyond the territorial sea),
U.S. Navy personnel must provide the foreign vessels participating with
a
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description of the mitigation measures to follow.
This final rule requires that in the event of a cetacean live
stranding (or near-shore atypical milling) event within the AFTT Study
Area or within 50 km (27 nmi) of the boundary of the AFTT Study Area,
where the NMFS Stranding Network is engaged in herding or other
interventions to return animals to the water, NMFS OPR will advise the
Action Proponents of the need to implement shutdown procedures for all
active acoustic sources or explosive devices within 50 km of the
stranding. Following this initial shutdown, NMFS will communicate with
the Action Proponents to determine whether circumstances support
modification of the shutdown zone. The Action Proponents may decline to
implement all or part of the shutdown if the holder of the LOA, or his/
her designee, determines that it is necessary for national security.
Shutdown procedures for live stranding or milling cetaceans include the
following:
If at any time, the marine mammal(s) die or are
euthanized, or if herding/intervention efforts are stopped, NMFS will
immediately advise that the shutdown around the animals' location is no
longer needed;
Otherwise, shutdown procedures will remain in effect until
NMFS determines and advises that all live animals involved have left
the area (either of their own volition or following an intervention);
and
If further observations of the marine mammals indicate the
potential for re-stranding, additional coordination will be required to
determine what measures are necessary to minimize that likelihood
(e.g., extending the shutdown or moving operations farther away) and to
implement those measures as appropriate.
Further, this final rule requires that within the first year of
AFTT Phase IV implementation, the Action Proponents shall work
collaboratively with the NMFS ESA Interagency Cooperation Division and
the NMFS Permits and Conservation Division to: (1) analyze and discuss
the application of new information from the NMFS North Atlantic Right
Whale Persistence Modelling Efforts toward AFTT mitigation measures;
(2) evaluate the practicability and conservation benefits of newly
proposed mitigation measure and/or changes to existing measures based
on information from the model; and (3) implement any new mitigation
measures or changes to existing measures that meet the Action
Proponents' Practicability Criteria and Sufficiently Beneficial
requirements.
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Activity-Based Mitigation
Activity-based mitigation is mitigation that the Action Proponents
must implement whenever and wherever an applicable military readiness
activity takes place within the AFTT Study Area. The primary objective
of activity-based mitigation is to reduce overlap of marine mammals
with stressors that have the potential to cause injury or mortality in
real time. Activity-based mitigations are fundamentally consistent
across stressor activity, although specific variations account for
differences in platform configuration, event characteristics, and
stressor types. The Action Proponents customize mitigation for each
applicable activity category or stressor. Activity-based mitigation
generally involves: (1) the use of one or more trained Lookouts to
diligently observe for marine mammals and other specific biological
resources (e.g., indicator species like floating vegetation, jelly
aggregations, large schools of fish, and flocks of seabirds) within a
mitigation zone; (2) requirements for Lookouts to immediately
communicate sightings of marine mammals and other specific biological
resources to the appropriate watch station for information
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dissemination; and (3) requirements for the watch station to implement
mitigation (e.g., halt an activity) until certain recommencement
conditions have been met. The remainder of the mitigation measures are
activity-based mitigation measures (table 19 through table 37)
organized by stressor type and activity category and include acoustic
stressors (i.e., active sonar, air guns, pile driving, weapons firing
noise), explosive stressors (i.e., sonobuoys, torpedoes, medium-caliber
and large-caliber projectiles, missiles and rockets, bombs, SINKEX,
mine counter-measure and neutralization activities, mine neutralization
involving Navy divers, line charge testing, ship shock trials), 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, non-explosive
bombs, mine shapes).
The Action Proponents must implement the mitigation measures
described in table 19 through table 37, as appropriate, in response to
an applicable sighting within, or entering into, the relevant
mitigation zone for acoustic stressors, explosives, and non-explosive
munitions. Each table describes the activities that the requirements
apply to, the required mitigation zones in which the Action Proponents
must take a mitigation action, the required number of Lookouts and
observation platform, the required mitigation actions that the Action
Proponents must take before, during, and/or after an activity, and a
required wait period prior to commencing or recommencing an activity
after a delay, power down, or shutdown of an activity.
The Action Proponents proposed wait periods because events cannot
be delayed or ceased indefinitely for the purpose of mitigation due to
impacts on safety, sustainability, and the ability to meet mission
requirements. Wait periods are designed to allow animals the maximum
amount of time practical to resurface (i.e., become available to be
observed) before activities resume. The Action Proponents factored in
an assumption that mitigation may need to be implemented more than once
when developing wait period durations. Wait periods are 15 minutes for
pile driving events, 10 minutes when events involve aircraft that are
typically fuel constrained, or 30 minutes when events involve only
vessels or aircraft that are not typically fuel constrained. NMFS
concurs with these wait periods.
If an applicable species (identified in relevant mitigation table)
is observed within a required mitigation zone prior to the initial
start of the activity, the Action Proponents must: (1) relocate the
event to a location where applicable species are not observed; or (2)
delay the initial start of the event (or stressor use) until one of the
``Mitigation Zone All-Clear Conditions'' (defined below) has been met.
If an applicable stressor is observed within a required mitigation zone
during the event (i.e., during use of the indicated source) the Action
Proponents must take the action described in the ``Mitigation Zones''
section of the table until one of the Mitigation Zone All-Clear
Conditions has been met.
For all activities, an activity may not commence or recommence
until one of the following ``Mitigation Zone All-Clear Conditions''
have been met: (1) a Lookout observes the applicable species exiting
the mitigation zone; (2) a Lookout concludes that the animal has exited
the mitigation zone based on its observed course, speed, and movement
relative to the mitigation zone; (3) a Lookout affirms the mitigation
zone has been clear from additional sightings for a designated ``wait
period''; or (4) for mobile events, the stressor has transited a
distance equal to double the mitigation zone size beyond the location
of the last sighting.
Activity-Based Mitigation for Active Acoustic Stressors
Mitigation measures for acoustic stressors are provided below and
include active acoustic sources (table 19), pile driving and extraction
(table 20), and weapons firing noise (table 21). Activity-based
mitigation for acoustic stressors does not apply to:
Sources not operated under positive control (i.e., sources
not actively controlled by a crewmember, e.g., unmanned platforms
performing predetermined operations);
Sources used for safety of navigation;
Sources used or deployed by aircraft operating at high
altitudes;
Sources used, deployed, or towed by unmanned platforms
except when escort vessels are already participating in the event and
have positive control over the source;
Sources used by submerged submarines;
De minimis sources;
Unattended sources, such as moored buoys used for acoustic
and oceanographic research; and
Vessel-based, unmanned vehicle-based, or towed in-water
sources when marine mammals (e.g., dolphins) are determined to be
intentionally swimming at the bow or alongside or directly behind the
vessel, vehicle, or device (e.g., to bow-ride or wake-ride).
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Activity-Based Mitigation for Explosive Stressors
Mitigation measures for explosive stressors are provided below and
include explosive bombs (table 22), explosive gunnery (table 23),
explosive line charges (table 24), explosive mine countermeasure and
neutralization without divers (table 25), explosive mine neutralization
with divers (table 26), explosive missiles and rockets (table 27),
explosive sonobuoys and research-based sub-surface explosives (table
28), explosive torpedoes (table 29), ship shock trials (table 30), and
SINKEX (table 31). After the event, the Action Proponents must observe
the area for marine mammals. Post-event observations are intended to
aid incident reporting requirements for marine mammals. Practicality
and the duration of post-event observations will be determined on site
by fuel restrictions and mission-essential follow-on commitments. For
example, it is more challenging to remain on-site for extended periods
of time for some activities due to factors such as range from the
target or altitude of an aircraft. This final rule requires that for
all activities involving explosives, if a marine mammal is visibly
injured or killed as a result of detonation, the use of explosives in
the event must be suspended immediately.
Activity-based mitigation for explosive stressors does not apply to
explosives:
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Deployed by aircraft operating at high altitudes;
Deployed by submerged submarines, except for explosive
torpedoes;
Deployed against aerial targets;
During vessel-launched missile or rocket events;
Used at or below the de minimis threshold; and
Deployed by unmanned platforms except when escort vessels
are already participating in the event and have positive control over
the explosive.
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Activity-Based Mitigation for Non-Explosive Ordnance
Mitigation measures for non-explosive ordnance are provided below
and include non-explosive aerial-deployed mines and bombs (table 32),
non-explosive gunnery (table 33), and non-explosive missiles and
rockets (table 34). Explosive aerial-deployed mines do not detonate
upon contact with the water surface and are therefore considered non-
explosive when mitigating the potential for a mine shape to strike a
marine mammal at the water surface. Activity-based mitigation for non-
explosive ordnance does not apply to non-explosive ordnance deployed:
By aircraft operating at high altitudes;
Against aerial targets;
During vessel-launched missile or rocket events; and
By unmanned platforms except when escort vessels are
already participating in the event and have positive control over
ordnance deployment.
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Activity-Based Mitigation for Physical Disturbance and Strike Stressors
Mitigation measures for physical disturbance and strike stressors
are provided below and include manned surface vessels (table 35),
unmanned vehicles (table 36), and towed in-water devices (table 37).
This final rule clarifies that activity-based mitigation for physical
disturbance and strike stressors will not be implemented:
By submerged submarines;
By unmanned vehicles except when escort vessels are
already participating in the event and have positive control over the
unmanned vehicle movements;
When marine mammals (e.g., dolphins) are determined to be
intentionally swimming at the bow, alongside the vessel or vehicle, or
directly behind the vessel or vehicle (e.g., to bow-ride or wake-ride);
When pinnipeds are hauled out on man-made navigational
structures, port structures, and vessels; and
When impractical based on mission requirements (e.g.,
during certain aspects of amphibious exercises).
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[[Page 50618]]
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Geographic Mitigation Areas
In addition to activity-based mitigation, the Action Proponents
must implement mitigation measures within mitigation areas to avoid or
minimize potential impacts on marine mammals. A full technical analysis
of the mitigation areas that the Action Proponents considered for
marine mammals is provided in section 5.7 (Geographic Mitigation) of
the 2025 AFTT Supplemental EIS/OEIS. The Action Proponents took into
account public comments received on the 2018 AFTT Draft EIS/OEIS, the
best available science, and the practicability of implementing
additional mitigation measures and has enhanced its mitigation areas
and mitigation measures beyond those that were included in the 2018-
2025 regulations to further reduce impacts on marine mammals.
Descriptions of the mitigation measures that the Action Proponents
must implement within mitigation areas are provided in table 38 through
table 46. The mitigation applies year-round unless specified otherwise
in the tables. The Changes from the Proposed Rule to the Final Rule
section summarizes the mitigation area changes that have occurred since
the proposed rule and the changes are further detailed in the
descriptions of each mitigation area.
NMFS conducted an independent analysis of the mitigation areas that
the Action Proponent must implement and are included in this rule.
NMFS' analysis indicates the measures in these geographic mitigation
areas are both practicable and will reduce the likelihood, magnitude,
or severity of adverse impacts to marine mammals or their habitat in
the manner described in the Action Proponents' analysis and this rule.
NMFS is heavily reliant on the Action Proponents' description of
operational practicability, since the Action Proponents are best
equipped to describe the degree to which a given mitigation measure
affects personnel safety or mission effectiveness, and is practical to
implement. The Action Proponents consider the required measures in this
rule to be practicable, and NMFS concurs. We further discuss the manner
in which the geographic mitigation areas will reduce the likelihood,
magnitude, or severity of adverse impacts to marine mammal species or
their habitat in the Analysis and Negligible Impact Determination
section.
Should national security require the Action Proponents to exceed
the requirements within the Geographic Mitigation Areas, Action
Proponent personnel must provide NMFS with advance notification and
include the information (e.g., sonar hours, explosives usage, or
restricted area use)
[[Page 50619]]
in its annual activity reports submitted to NMFS.
Table 38 details geographic mitigation related to ship shock
trials, which involve the use of explosives. Ship shock trials are
conducted only within two established ship shock trial boxes: one
within the Gulf of America and one that overlaps the Jacksonville
OPAREA. The boundaries of the mitigation areas match the boundaries of
each ship shock trial box.
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Table 39 details geographic mitigation related to MTEs (i.e.,
Composite Training Unit Exercises and Sustainment Exercises).
[[Page 50621]]
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Table 40 details geographic mitigation related to active sonar and
explosives (and special reporting for their use), and physical
disturbance and strike stressors off the northeastern United States.
The mitigation area extent matches that of
[[Page 50622]]
the NARW foraging critical habitat designated in 2016 (81 FR 4838,
February 26, 2016). Mitigation is designed to protect individual NARWs
within their foraging critical habitat. Mitigation will also protect
individuals of other species whose biologically significant habitats
overlap the mitigation area, including harbor porpoises and humpback,
minke, sei, and fin whales. Special reporting for the use of acoustics
and explosives is also required for this area (see Reporting section
for details).
[[Page 50623]]
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[[Page 50624]]
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[[Page 50625]]
Table 41 details geographic mitigation related to active sonar and
special reporting for the use of active sonar and in-water explosives
within the Gulf of Maine. Special reporting for the use of acoustics
and explosives is also required for this area (see Reporting section
for details).
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Table 42 details geographic mitigation related to propulsion
testing in the area south of Martha's Vineyard and Nantucket Islands.
This mitigation area is new to this final rule.
[GRAPHIC] [TIFF OMITTED] TR07NO25.090
Table 43 details geographic mitigation related to active sonar and
explosives (and special reporting for their use), and physical
disturbance and strike stressors in the Jacksonville OPAREA. Mitigation
is a continuation of existing measures, with clarification that
requirements pertain to in-water stressors (i.e., not activities with
no potential marine mammal impacts, such as air-to-air activities).
[[Page 50626]]
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Table 44 details geographic mitigation related to active sonar and
explosives (and special reporting for their use), and physical
disturbance and strike stressors off the southeastern U.S. The
mitigation area is the largest area practical to implement within the
NARW reproduction critical habitat designated by NMFS in 2016 (81 FR
4838, February 26, 2016). Mitigation is designed to protect
reproductive mothers, calves, and mother-calf pairs within the only
known NARW calving habitat. Mitigation benefits would be substantial
because the mitigation area encompasses the Georgia and northeastern
Florida coastlines (where the highest seasonal concentrations occur)
and coastal extent of the Jacksonville OPAREA (an Action Proponent
concentration area). Special reporting for the use of acoustics and
explosives is also required for this area (see Reporting section for
details).
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[[Page 50628]]
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Table 45 details geographic mitigation related to active sonar,
explosives, and physical disturbance and strike stressors within the
boundary of the U.S. EEZ on the East Coast (i.e., the full extent of
where NMFS could potentially establish Dynamic Management Areas).
[[Page 50629]]
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Table 46 details geographic mitigation related to active sonar and
explosives (and special reporting for their use) in the northeastern
Gulf of America. The mitigation area extent aligns with this species'
small and resident population
[[Page 50630]]
area identified by NMFS in its 2016 status review (Rosel et al., 2016).
Special reporting for the use of acoustics and explosives is also
required for this area (see Reporting section for details).
[[Page 50631]]
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[[Page 50632]]
Mitigation Conclusions
NMFS has carefully evaluated the Action Proponents' proposed
mitigation measures--many of which were developed with NMFS' input
during the previous phases of AFTT authorizations but several of which
are new since implementation of the 2018 to 2025 regulations, including
some recommendations from public comments on the 2025 proposed rule--
and considered a broad range of other measures (i.e., the measures
considered but eliminated in the 2018 AFTT Final EIS/OEIS, which
reflect many of the comments that have arisen from public input or
through discussion with NMFS 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: (1) 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; (2) the proven or likely efficacy of the measures; and (3) 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 Action Proponents' proposed
measures, as well as other measures considered by the Action Proponents
and NMFS, NMFS has determined the mitigation measures included in this
rule are the appropriate means of effecting the least practicable
adverse impact on 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
component helps further ensure that mitigation is regularly assessed
and provides a mechanism to improve the mitigation, based on the
factors above, through modification as appropriate. Thus, NMFS
concludes the mitigation measures required in this rule satisfy the
statutory standard and that any adverse impacts that remain cannot be
practicably further mitigated.
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.
We provided a detailed discussion of monitoring in our proposed
rule (90 FR 19858, May 9, 2025). In the Proposed Monitoring section of
the proposed rule, NMFS provided a description of the Navy Marine
Species Research and Monitoring Strategic Framework, and past and
current Navy monitoring in the AFTT Study Area. All of this information
remains valid and applicable and is not repeated here.
The Navy's marine species monitoring program supports several
monitoring projects in the AFTT Study Area at any given time.
Additional details on the scientific objectives for each project can be
found at: https://www.navymarinespeciesmonitoring.us/regions/atlantic/current-projects/. Future monitoring efforts by the Action Proponents
in the AFTT Study Area are anticipated to continue along the same
objectives: establish the baseline habitat uses and movement patterns;
establish the baseline behavior (foraging, dive patterns, etc.);
evaluate potential exposure and behavioral responses of marine mammals
exposed to training and testing activities; and support conservation
and management of NARWs.
Adaptive Management
The regulations governing the take of marine mammals incidental to
military readiness activities in the AFTT Study Area contain an
adaptive management component. Our understanding of the effects of
military readiness activities (e.g., acoustic and explosive stressors)
on marine mammals continues to evolve, which makes the inclusion of an
adaptive management component both valuable and necessary within the
context of 7-year regulations.
The reporting requirements associated with this 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 Action Proponents regarding
practicability) on an annual or biennial basis if mitigation or
monitoring measures should be modified (including additions or
deletions). Mitigation measures could be modified if new data suggests
that such modifications would have a reasonable likelihood of more
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
would publish a notice of the planned LOAs 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 exercise reports, as required by MMPA
authorizations; (2) compiled results of Navy-funded research and
development studies; (3) results from specific stranding
investigations; (4) results from general marine mammal and sound
research; and (5) any information which reveals that marine mammals may
have been taken in a manner, extent, or number not authorized by these
regulations or subsequent LOAs. The results from monitoring reports and
other studies may be viewed at https://www.navymarinespeciesmonitoring.us.
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 at: https://www.navymarinespeciesmonitoring.us.
We provided a detailed discussion of reporting in our proposed rule
(90 FR 19858, May 9, 2025). In the Proposed Reporting section of the
proposed rule, NMFS provided descriptions of: special reporting for
geographic mitigation areas; the Notification and Reporting Plan for
injured, live stranded, or dead marine mammals; annual AFTT Study Area
marine species monitoring report;
[[Page 50633]]
annual AFTT training and testing reports; and other reporting and
coordination. All of this information remains valid and applicable and
is not repeated here.
In addition to the reporting requirements included in the proposed
rule, this final rule requires that in the annual AFTT training and
testing reports Navy personnel must confirm that foreign military use
of sonar and explosives, when such militaries are participating in a
U.S. Navy-led exercise or event, combined with the Action Proponents'
use of sonar and explosives, would not cause exceedance of the analyzed
levels within each NAEMO modeled sonar and explosive bin used for
estimating predicted impacts.
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 (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
taken by Level A harassment or Level B harassment (as presented in
table 16), NMFS considers other factors, such as the likely nature of
any responses (e.g., intensity, duration) and 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. We also assess the number, intensity, and context of
estimated takes by evaluating this information relative to population
status. 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 environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, other ongoing sources of human-caused
mortality, and ambient noise levels).
In the Estimated Take of Marine Mammals section, we identified the
subset of potential effects that would be expected to qualify as take
both annually and over the 7-year period covered by this rule and then
identified the maximum number of takes we believe could occur
(mortality) or are reasonably expected to occur (harassment) based on
the methods described. The impact that any given take will have is
dependent on many case-specific factors that need to be considered in
the negligible impact analysis (e.g., the context of behavioral
exposures such as duration or intensity of a disturbance, the health of
impacted animals, the status of a species that incurs fitness-level
impacts to individuals). For this rule, we evaluated the likely impacts
of the enumerated maximum number of harassment takes that are
authorized and reasonably expected to occur, in the context of the
specific circumstances surrounding these predicted takes. We also
include a specific assessment of serious injury or mortality (M/SI)
takes that could occur, as well as consideration of the traits and
statuses of the affected species and stocks. 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
stock or species. Because all of the Action Proponents' specified
activities would occur within the ranges of the marine mammal stocks
identified in the rule, all negligible impact analyses and
determinations are at the stock level (i.e., additional species-level
determinations are not needed).
Harassment
The specified activities reflect representative levels of military
readiness activities. The Description of Specified Activity section
describes annual activities. There may be some flexibility in the exact
number of hours, items, or detonations that may vary from year to year,
but take totals would not exceed the maximum annual totals and 7-year
totals indicated in table 16. We base our analysis and negligible
impact determination on the maximum number of takes that would be
reasonably expected to occur annually and are authorized, although, as
stated before, the number of takes is only one part of the analysis,
which includes extensive 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 immediately below that applies to all the species listed in
table 16, given that some of the anticipated effects of the Action
Proponents' military readiness activities on marine mammals are
expected to be relatively similar in nature. Below that, we provide
additional information specific to mysticetes, odontocetes, and
pinnipeds and, finally, break our analysis into species (and/or
stocks), or groups of species (and the associated stocks) where
relevant similarities exist, to provide more specific information
related to the anticipated effects on individuals of a specific stock
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 or stock. Organizing our analysis by grouping species or stocks
that share common traits or that will respond similarly to effects of
the Action Proponents' activities and then providing species- or stock-
specific information allows us to avoid duplication while assuring that
we have analyzed the effects of the specified activities on each
affected species or stock.
The Action Proponents' harassment take request is based on one
model for pile driving and a second model (NAEMO) for all other
acoustic stressors, which NMFS reviewed and concurs does appropriately
estimate the maximum amount of harassment that is reasonably likely to
occur. As described in more detail in the Navy Acoustics Effects Model
section of the proposed rule (90 FR 19858, May 9, 2025), NAEMO
calculates: (1) sound energy propagation from sonar and other
transducers, air guns, and explosives during military readiness
activities; (2) the sound or impulse received by animat dosimeters
representing marine mammals distributed in the area around the modeled
activity; and (3) whether the sound or impulse energy received by a
marine mammal exceeds the thresholds for effects. Assumptions in the
Navy models intentionally err on the side of overestimation when there
are unknowns. The effects of the specified activities are modeled as
though they would occur regardless of proximity to marine mammals,
meaning that no activity-based mitigation is considered (e.g., no power
down or shut down). However, the modeling does quantitatively consider
the possibility that marine mammals would avoid continued or repeated
sound exposures to some degree, based on a species' sensitivity to
behavioral disturbance. Additionally, the sonar modeling reflects some,
but not all, of the geographic mitigation measures. NMFS provided input
to, independently reviewed, and concurred with the Action Proponents on
this process and
[[Page 50634]]
the Action Proponents' analysis, which is described in detail in
section 6 of the application, was used to quantify harassment takes for
this rule.
The Action Proponents 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 elicit a response of equal magnitude (DeRuiter,
2012)). The estimated number of takes by Level A harassment and Level B
harassment does not equate to the number of individual animals the
Action Proponents expect 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 over the 7-
year period. These instances may represent either brief exposures
(seconds or minutes) or, in some cases, longer durations of exposure
within a day. In some cases, an animal that incurs a single take by AUD
INJ or TTS may also experience a direct behavioral harassment from the
same exposure. Some individuals may experience multiple instances of
take (meaning over multiple days) over the course of the year, which
means that the number of individuals taken is smaller than the total
estimated takes. Generally speaking, the higher the number of takes as
compared to the population abundance, the more repeated takes of
individuals are likely, and the higher the actual percentage of
individuals in the population that are likely taken at least once in a
year. We look at this comparative metric (number of takes to population
abundance) to give us a relative sense of where a larger portion of a
species is being taken by the specified activities, where there is a
likelihood that the same individuals are being taken across multiple
days, and whether the number of days might be higher or more likely
sequential. Where the number of instances of take is less than 100
percent of the abundance, and there is no information to specifically
suggest that some subset of animals is known to congregate in an area
in which activities are regularly occurring (e.g., a small resident
population, takes occurring in a known important area such as a BIA, or
a large portion of the takes occurring in a certain region and season),
the overall likelihood and number of repeated takes is generally
considered low, as it could, on one extreme, mean that every take
represents a separate individual in the population being taken on one
day (a minimal impact to an individual) or, more likely, that some
smaller number of individuals are taken on one day annually and some
are taken on a few, not likely sequential, days annually, and of course
some are not taken at all.
In the ocean, the use of sonar and other active acoustic sources is
often transient and is unlikely to repeatedly expose the same
individual animals within a short period, for example within one
specific exercise. However, for some individuals of some species,
repeated exposures across different activities could occur over the
year, especially where events occur in generally the same area with
more resident species. In short, for some species, we expect that the
total anticipated takes represent exposures of a smaller number of
individuals of which some would be exposed multiple times, but, based
on the nature of the specified activities and the movement patterns of
marine mammals, it is unlikely that individuals from most stocks would
be taken over more than a few days within a given year. This means that
even where repeated takes of individuals are likely to occur, they are
more likely to result from non-sequential exposures from different
activities, and, even if sequential, individual animals are not
predicted to be taken for more than several days in a row, at most. As
described elsewhere, the nature of the majority of the exposures would
be expected to be of a less severe nature, and based on the numbers, it
is likely that any individual exposed multiple times is still taken on
only a small percentage of the days of the year. It is more likely that
not every individual is taken, or perhaps a smaller subset is taken
with a slightly higher average and larger variability of highs and
lows, but still with no reason to think that, for most species or
stocks, any individuals would be taken a significant portion of the
days of the year.
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 Underwater Sound on Marine
Mammals section of the proposed rule (90 FR 19858, May 9, 2025), 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. Takes by Level B
harassment, then, may have a stress-related physiological component as
well; however, we would not expect the Action Proponents' generally
short-term, intermittent, and (typically in the case of sonar)
transitory 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.
Behavioral Response
The estimates calculated using the BRF do not differentiate between
the different types of behavioral responses that qualify as Level B
harassment. As described in the application, the Action Proponents
identified (with NMFS' input) that moderate behavioral responses, as
characterized in Southall et al. (2021), would be considered a take.
The behavioral responses predicted by the BRFs are assumed to be
moderate severity exposures (e.g., altered migration paths or dive
profiles, interrupted nursing, breeding or feeding, or avoidance) that
may last for the duration of an exposure. The Action Proponents then
compiled the available data indicating at what received levels and
distances those responses have occurred and used the indicated
literature to build biphasic behavioral response curves and cut-off
conditions that are used to predict how many instances of Level B
behavioral harassment occur in a day (see the Criteria and Thresholds
Technical Report). Take estimates alone do not provide information
regarding the potential fitness or other biological consequences of the
responses on the affected individuals. We therefore consider 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.
Use of sonar and other transducers would typically be transient and
temporary. The majority of acoustic effects to individual animals from
sonar and other active sound sources during military readiness
activities would be primarily from anti-submarine warfare events. It is
important to note that, although anti-submarine warfare is one of the
warfare areas of focus during MTEs, there are significant periods when
active anti-submarine warfare sonars are not in use. Nevertheless,
behavioral responses are assumed more
[[Page 50635]]
likely to be significant during MTEs than during other anti-submarine
warfare activities due to the duration (i.e., multiple days), scale
(i.e., multiple sonar platforms), and use of high-power hull-mounted
sonar in the MTEs. In other words, in the range of potential behavioral
effects that might be expected as part of a response that qualifies as
an instance of Level B behavioral harassment (which by nature of the
way it is modeled/counted, occurs within 1 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, and that 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, 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
expected to occur infrequently.
To help assess this, for sonar (LFAS/MFAS/high-frequency active
sonar (HFAS)) used in the AFTT Study Area, the Action Proponents
provided information estimating the instances of take by Level B
harassment by behavioral disturbance under each BRF that would occur
within 6-dB increments (discussed in the Group and Species-Specific
Analyses section), and by distance in 5-km (2.7-nmi) bins in section
2.3.3 of appendix A to the application. As mentioned above, all else
being equal, an animal's exposure to a higher received level is more
likely to result in a behavioral response that is more likely to lead
to adverse effects, which could more likely accumulate to impacts on
reproductive success or survivorship of the animal, but other
contextual factors (e.g., distance, duration of exposure, and
behavioral state of the animals) are also important (Di Clemente et
al., 2018; Ellison et al., 2012; Moore and Barlow, 2013, Southall et
al., 2019, Wensveen et al., 2017, etc.). The majority of takes by Level
B harassment are expected to be in the form of comparatively milder
responses (i.e., lower-level exposures that still qualify as take, but
would likely be less severe along the continuum of responses that
qualify as take) of a generally shorter duration. We anticipate more
severe effects from takes when animals are exposed to higher received
levels of sound or at closer proximity to the source. Because species
belonging to taxa that share common characteristics are likely to
respond and be affected in similar ways, these discussions are
presented within each species group below in the Group and Species-
Specific Analyses section. As discussed in the Behavioral Responses
section of the proposed rule (90 FR 19858, May 9, 2025), behavioral
response is likely highly variable between species, individuals within
a species, and context of the exposure. Specifically, given a range of
behavioral responses that may be classified as Level B harassment, to
the degree that higher received levels of sound are expected to result
in more severe behavioral responses, only a smaller percentage of the
anticipated Level B harassment from the specified activities might
result in more severe responses (see the Group and Species-Specific
Analyses section below for more detailed information).
Diel Cycle
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing on a diel cycle (i.e., 24-hour cycle).
Behavioral responses 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). 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). Consequently, a behavioral response
lasting less than 1 day and not recurring on subsequent days is not
considered severe unless it could directly affect reproduction or
survival (Southall et al., 2007). Note that there is a difference
between multiple-day substantive behavioral responses and multiple-day
anthropogenic activities. For example, just because an at-sea exercise
lasts for multiple days does not necessarily mean that individual
animals are either exposed to those exercises for multiple days or,
further, exposed in a manner resulting in a sustained multiple day
substantive behavioral response. Large multi-day Navy exercises, such
as anti-submarine warfare activities, typically include vessels moving
faster than while in transit (typically 10-15 kn (18.5-27.8 km/hr) or
higher) and generally cover large areas that are relatively far from
shore (typically more than 3 nmi (5.6 km) from shore) and in waters
greater than 600 ft (182.9 m) deep. Marine mammals are moving as well,
which would make it unlikely that the same animal could remain in the
immediate vicinity of the ship for the entire duration of the exercise.
Further, the Action Proponents do not necessarily operate active sonar
the entire time during an exercise. While it is certainly possible that
these sorts of exercises could overlap with individual marine mammals
multiple days in a row at levels above those anticipated to result in a
take, because of the factors mentioned above, it is considered unlikely
for the majority of takes. However, it is also worth noting that the
Action Proponents conduct many different types of noise-producing
activities over the course of the year and it is likely that some
marine mammals will be exposed to more than one activity and taken on
multiple days, even if they are not sequential.
Durations of Navy activities utilizing tactical sonar sources and
explosives vary and are fully described in chapter 2 of the 2024 AFTT
Draft Supplemental EIS/OEIS. Sonar used during anti-submarine warfare
would impart the greatest amount of acoustic energy of any category of
sonar and other transducers analyzed in the application and include
hull-mounted, towed, line array, sonobuoy, helicopter dipping, and
torpedo sonars. Most anti-submarine warfare sonars are MFAS (1-10 kHz);
however, some sources may use higher or lower frequencies. Anti-
submarine warfare training activities using hull-mounted sonar planned
for the AFTT Study Area generally last for only a few hours. However,
anti-submarine warfare testing activities range from several hours, to
a single or more than 1 day but less than 10 days, to more than 10 days
for large integrated anti-submarine warfare MTEs (see section 1 of the
application). For these multi-day exercises there will typically be
extended intervals of non-activity in between active sonar periods.
Because of the need to train in a large variety of situations, the Navy
conducts anti-submarine warfare training exercises in varying
locations. Given the average length and dynamic nature of anti-
submarine warfare exercises (times of sonar use) and typical vessel
speed, combined with the fact that the majority of the cetaceans would
not likely remain in proximity to the sound source, it is unlikely that
an animal would be exposed to LFAS/MFAS/HFAS at levels
[[Page 50636]]
or durations likely to result in a substantive response that would then
be carried on for more than 1 day or on successive days.
Most planned explosive events are instantaneous or scheduled to
occur over a short duration (less than 2 hours) and the explosive
component of these activities lasts only for minutes. Although
explosive exercises 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.
Although SINKEXs may last for up to 48 hours (4-8 hours typically,
possibly 1-2 days), they are almost always completed in a single day
and only one event is planned annually for the AFTT Study Area (see
section 1 of the application). They are stationary and conducted in
deep, open water (where fewer marine mammals would typically be
expected to be randomly encountered), and they have rigorous monitoring
(see table 31) and shutdown procedures all of which make it unlikely
that individuals would be exposed to the exercise for extended periods
or on consecutive days, though some individuals may be exposed on
multiple 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 equated, as appropriate, to harassment takes. As
further noted, for active acoustics it is more challenging to parse out
the number of individuals taken by Level B harassment and the number of
times those individuals are taken from this larger number of instances,
though factors such as movement ecology (e.g., is the species resident
and more likely to remain in closer proximity to ongoing activities,
versus nomadic or migratory; Keen et al. 2021) or whether there are
known BIAs where animals are known to congregate can help inform this.
One method that NMFS uses to help better understand the overall scope
of the impacts is to compare these total instances of take against the
abundance of that species (or stock if applicable). For example, if
there are 100 harassment takes in a population of 100, one can assume
either that every individual was exposed above acoustic thresholds once
per year, or that some smaller number were exposed a few times per
year, and a few were not exposed at all. Where the instances of take
exceed 100 percent of the population, multiple takes of some
individuals are predicted and expected to occur within a year.
Generally speaking, the higher the number of takes as compared to the
population abundance, the more multiple takes of individuals are
likely, and the higher the actual percentage of individuals in the
population that are likely taken at least once in a year. We look at
this comparative metric to give us a relative sense of where larger
portions of the species are being taken by the Action Proponents'
activities and where there is a higher likelihood that the same
individuals are being taken across multiple days and where that number
of days might be higher. It also provides a relative picture of the
scale of impacts on each species.
In the ocean, unlike a modeling simulation with static animals, the
transient nature of sonar use makes it unlikely to repeatedly expose
the same individual animals within a short period, for example, within
one specific exercise. However, some repeated exposures across
different activities could occur over the year with more resident
species. In short, we expect the total anticipated takes represent
exposures of a smaller number of individuals of which some could be
exposed multiple times, but, based on the nature of the Action
Proponents' activities and the movement patterns of marine mammals, it
is unlikely that any particular subset would be taken over more than
several sequential days (with a few possible exceptions discussed in
the species-specific conclusions). In other cases, such as during
pierside sonar testing at Naval Station Norfolk, repeated exposures of
the same individuals may be more likely given the concentrated area
within which the operations occur and the likelihood that a smaller
number of animals would routinely use the affected habitat.
When calculating the proportion of a population taken (e.g., the
number of takes divided by population abundance), which can also be
helpful in estimating the number of days over which some individuals
may be taken, it is important to choose an appropriate population
estimate against which to make the comparison. Herein, NMFS considers
two potential abundance estimates, the SARs and the NMSDD abundance
estimates. The SARs, where available, provide the official population
estimate for a given species or stock in U.S. waters in a given year.
These estimates are typically generated from the most recent shipboard
and/or aerial surveys conducted, and in some cases, the estimates show
substantial year-to-year variability. When the stock is known to range
well outside of U.S. EEZ boundaries, population estimates based on
surveys conducted only within the U.S. EEZ are known to be
underestimates. The NMSDD-derived abundance estimates are abundances
for within the U.S. EEZ boundaries only and, therefore, differ from
some SAR abundance estimates.
The SAR and NMSDD abundance estimates can differ substantially
because these estimates may be based on different methods and data
sources. For example, the SARs consider data only from the past 8 year
period, whereas the NMSDD considers a longer data history. Further, the
SARs estimate the number of animals in a population but not spatial
densities. NMSDD uses predictive density models to estimate species
presence, even where sighting data is limited or lacking altogether.
Thus, NMSDD density models beyond the U.S. EEZ have greater uncertainty
than those within the U.S. EEZ, where most proposed activities would
occur. Each density model is limited to the variables and assumptions
considered by the original data source provider. NMFS considered these
factors and others described in the technical report ``U.S. Navy Marine
Species Density Database Phase IV for the Atlantic Fleet Training and
Testing Study Area'' (U.S. Department of the Navy, 2024c), hereafter
referred to as the Density Technical Report, when comparing the
estimated takes to current population abundances for each species or
stock.
In consideration of the factors described above, to estimate
repeated impacts across large areas relative to species geographic
distributions, comparing the impacts predicted in NAEMO to abundances
predicted using the NMSDD models is usually preferable. By comparing
estimated take to the NMSDD abundance estimates, impacts and abundance
estimates are based on the same underlying assumptions about a species'
presence. NMFS has compared the estimated take to the NMSDD abundance
estimates herein for all stocks, with the exception of stocks where the
abundance information fits into one of the following scenarios, in
which case NMFS concluded that comparison to the SAR abundance estimate
is more appropriate: (1) a species' or stocks' range extends beyond the
U.S. EEZ and the SAR abundance estimate is greater than the NMSDD
abundance. For highly migratory species (e.g., large whales) or those
whose geographic distribution extends beyond the boundaries of the
[[Page 50637]]
AFTT Study Area (e.g., populations with distribution along the entire
western Atlantic Ocean rather than just the AFTT Study Area),
comparisons to the SAR are appropriate. Many of the stocks present in
the AFTT Study Area have ranges significantly larger than the AFTT
Study Area, and that abundance is captured by the SAR. A good
descriptive example is migrating large whales, which occur seasonally
in the AFTT Study Area. Therefore, at any one time there may be a
stable number of animals, but over the course of the entire year the
entire population may pass through the AFTT Study Area. Thus,: (1)
comparing the estimated takes to an abundance, in this case the SAR
abundance, which represents the total population, may be more
appropriate than modeled abundances for only the AFTT Study Area; and
(2) when the current minimum population estimate in the SAR is greater
than the NMSDD abundance, regardless of whether the stock range extends
beyond the EEZ. The NMSDD and SAR abundance estimates are both included
in table 50 (mysticetes), table 52 (sperm whales, dwarf sperm whales,
and pygmy sperm whales), table 54 (beaked whales), table 56 (dolphins
and small whales), table 58 (porpoises), and table 60 (pinnipeds), and
each table indicates which stock abundance estimate was selected for
comparison to the take estimate for each species or stock.
Temporary Threshold Shift
NMFS and the Navy have estimated that all species of marine mammals
may incur some level of TTS from active sonar. As mentioned previously,
in general, TTS can last from a few minutes to days, be of varying
degree, and occur across various frequency bandwidths, all of which
determine the severity of the impacts on the affected individual, which
can range from minor to more severe. Table 5 through table 13 indicate
the number of takes by TTS that may be incurred by different species
from exposure to active sonar, air guns, pile driving, and explosives.
The TTS incurred by an animal is primarily characterized by three
characteristics:
(1) Frequency--Available data suggest that most TTS occurs in the
frequency range of the source up to one octave higher than the source
(with the maximum TTS at one-half octave above) (Finneran, 2015;
Southall et al., 2019). The Navy's MF anti-submarine warfare sources,
which are the highest power and most numerous sources and the ones that
cause the most take by TTS, utilize the 1-10 kHz frequency band, which
suggests that if TTS were to be induced by any of these MF sources it
would be in a frequency band somewhere between approximately 1 and 20
kHz, which is in the range of communication calls for many odontocetes
but below the range of the echolocation signals used for foraging.
There are fewer hours of HF source use and the sounds would attenuate
more quickly, plus they have lower source levels, but if an animal were
to incur TTS from these sources, it would cover a higher frequency
range (sources are between 10 and 100 kHz, which means that TTS could
range up to the highest frequencies audible to VHF cetaceans,
approaching 200 kHz), which could overlap with the range in which some
odontocetes communicate or echolocate. However, HF systems are
typically used less frequently and for shorter time periods than
surface ship and aircraft MF systems, so TTS from HF sources is less
likely than from MF sources. There are fewer LF sources and the
majority are used in the more readily mitigated testing environment,
and TTS from LF sources would most likely occur below 2 kHz, which is
in the range where many mysticetes communicate and also where other
auditory cues are located (e.g., waves, snapping shrimp, fish prey).
Also of note, the majority of sonar sources from which TTS may be
incurred occupy a narrow frequency band, which means that the TTS
incurred would also be across a narrower band (i.e., not affecting the
majority of an animal's hearing range).
(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 SPL is higher
or the duration is longer). The threshold for the onset of TTS was
discussed in the Hearing Loss and Auditory Injury section of the
proposed rule (90 FR 19858, May 9, 2025). 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, which would be
difficult considering the Lookouts and the nominal speed of an active
sonar vessel (10-15 kn (18.5-27.8 km/hr)) and the relative motion
between the sonar vessel and the animal. In the TTS studies discussed
in the Potential Effects of Specified Activities on Marine Mammals and
Their Habitat section of the proposed rule (90 FR 19858, May 9, 2025),
some using exposures of almost an hour in duration or up to 217 SEL,
most of the TTS induced was 15 dB or less, though Finneran et al.
(2007) induced 43 dB of TTS with a 64-second exposure to a 20 kHz
source. The SQS-53 (MFAS) hull-mounted sonar (MF1) nominally emits a
short (1-second) ping typically every 50 seconds, incurring those
levels of TTS due to this source is highly unlikely. Sources with
higher duty cycles produce longer ranges to effects and contribute to
auditory effects from this action. Since any hull-mounted sonar, such
as the SQS-53, engaged in anti-submarine warfare training would be
moving at between 10 and 15 kn (18.5 and 27.8 km/hr) and nominally
pinging every 50 seconds, the vessel will have traveled a minimum
distance of approximately 843.2 ft (257 m) during the time between
those pings. For a Navy vessel moving at a nominal 10 kn (18.5 km/hr),
it is unlikely a marine mammal would track with the ship and could
maintain speed parallel to the ship to receive adequate energy over
successive pings to suffer TTS. In short, given the anticipated
duration and levels of sound exposure, we would not expect marine
mammals to incur more than relatively low levels of TTS in most cases
for sonar exposure. To add context to this degree of TTS, individual
marine mammals may regularly experience variations of 6 dB differences
in hearing sensitivity in their lifetime (Finneran et al., 2000;
Finneran et al., 2002; Schlundt et al., 2000).
(3) Duration of TTS (recovery time)--As discussed in the Potential
Effects of Specified Activities on Marine Mammals and Their Habitat
section of the proposed rule (90 FR 19858, May 9, 2025), in the TTS
laboratory studies using exposures of up to an hour in duration or up
to 217 dB SEL, most individuals recovered within 1 day (or less, often
in minutes) (Kastelein, 2020b). One study resulted in a recovery that
took 4 days (Finneran et al., 2015; Southall et al. 2019). However,
there is evidence that repeated exposures resulting in TTS could
potentially lead to residual threshold shifts that persist for longer
durations and can result in PTS (Reichmuth et al., 2019).
Compared to laboratory studies, marine mammals are likely to
experience lower SELs from sonar used in the AFTT Study Area due to
movement of the source and animals, and because of the lower duty
cycles typical of higher power sources (though some of the Navy MF1C
sources have higher duty cycles). Therefore, TTS resulting from MFAS
would likely be of lesser magnitude and duration compared to laboratory
studies. Also, for the same reasons discussed above in the Diel Cycle
section, and because of the short distance between the source
[[Page 50638]]
and animals needed to reach high SELs, it is unlikely that animals
would be exposed to the levels necessary to induce TTS in subsequent
time periods such that hearing recovery is impeded. Additionally,
though the frequency range of TTS that marine mammals might incur would
overlap with some of the frequency ranges of their vocalization types,
the frequency range of TTS from MFAS would not usually span the entire
frequency range of one vocalization type, much less span all types of
vocalizations or other critical auditory cues.
As a general point, the majority of the TTS takes are the result of
exposure to hull-mounted MFAS (MF narrower band sources), with fewer
from explosives (broad-band lower frequency sources), and even fewer
from LFAS or HFAS sources (narrower band). As described above, we
expect the majority of these takes to be in the form of mild, short-
term (minutes to hours), narrower band (affecting only a portion of the
animal's hearing range) TTS. This means that for one to several times
per year, for several minutes, maybe a few hours, or at most in limited
circumstances a few days, a taken individual will have diminished
hearing sensitivity (more than natural variation, but nowhere near
total deafness). More often than not, such an exposure would occur
within a narrower mid- to higher frequency band that may overlap part
(but not all) of a communication, echolocation, or predator range, but
sometimes across a lower or broader bandwidth. The significance of TTS
is also related to the auditory cues that are germane within the time
period that the animal incurs the TTS. For example, if an odontocete
has TTS at echolocation frequencies, but incurs it at night when it is
resting and not feeding, it is not impactful. In short, the expected
results of any one of these limited 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, it is unlikely that individuals would experience repeated or
high degree TTS overlapping in frequency and time with signals critical
for behaviors that would impact overall fitness.
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 occurs only 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 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 occurs. Also
inherent in the concept of masking is the fact that the potential for
the effect is present only 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 relative movement of vessels and 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 farther than
higher frequencies and because they are more likely to overlap both the
narrower LF calls of mysticetes, as well as many non-communication cues
such as fish and invertebrate prey, and geologic sounds that inform
navigation. Masking is also more of a concern from continuous sources
(versus intermittent sonar signals) where there is no quiet time
between pulses and detection and interpretation of auditory signals is
likely more challenging. For these reasons, dense aggregations of, and
long exposure to, continuous LF activity are much more of a concern for
masking, whereas comparatively short-term exposure to the predominantly
intermittent pulses of often narrow frequency range MFAS or HFAS, or
explosions are not expected to result in a meaningful amount of
masking. While the Action Proponents occasionally use LF and more
continuous sources, it is not in the contemporaneous aggregate amounts
that would be expected to accrue to degrees that would have the
potential to affect reproductive success or survival. Additional detail
is provided below.
Standard hull-mounted MFAS typically pings every 50 seconds. Some
hull-mounted anti-submarine sonars can also be used in an object
detection mode known as ``Kingfisher'' mode (e.g., used on vessels when
transiting to and from port) where pulse length is shorter but pings
are much closer together in both time and space since the vessel goes
slower when operating in this mode, and during which an increased
likelihood of masking in the vicinity of vessel could be expected. For
the majority of other sources, the pulse length is significantly
shorter than hull-mounted active sonar, on the order of several
microseconds to tens of milliseconds. Some of the vocalizations that
many marine mammals make are less than 1 second long so, for example,
with hull-mounted sonar, there would be a 1 in 50 chance (only if the
source was in close enough proximity for the sound to exceed the signal
that is being detected) that a single vocalization might be masked by a
ping. However, when vocalizations (or series of vocalizations) are
longer than the 1 second pulse of hull-mounted sonar, or when the
pulses are only several microseconds long, the majority of most
animals' vocalizations would not be masked.
Most anti-submarine warfare sonars and countermeasures use MF
frequencies and a few use LF and HF frequencies. Most of these sonar
signals are limited in the temporal, frequency, and spatial domains.
The duration of most individual sounds is short, lasting up to a few
seconds each. A few systems operate with higher duty cycles or nearly
continuously, but they typically use lower power, which means that an
animal would have to be closer, or in the vicinity for a longer time,
to be masked to the same degree as by a higher level source.
Nevertheless, masking could occasionally occur at closer ranges to
these high-duty cycle and continuous active sonar systems, but as
described previously, it would be expected to be of a short duration.
While data are lacking on behavioral responses of marine mammals to
continuously active sonars, mysticete species are known to habituate to
novel and continuous sounds (Nowacek et al., 2004), suggesting that
they are likely to have similar responses to high-duty cycle sonars.
Furthermore, most of these systems are hull-mounted on surface ships
with the ships moving at least 10 kn (18.5 km/hr), and it is unlikely
that the ship and the marine mammal would continue to move in the same
direction and the marine mammal subjected to the same exposure due to
that
[[Page 50639]]
movement. Most anti-submarine warfare activities are geographically
dispersed and last for only a few hours, often with intermittent sonar
use even within this period. Most anti-submarine warfare sonars also
have a narrow frequency band (typically less than one-third octave).
These factors reduce the likelihood of sources causing significant
masking. HF signals (above 10 kHz) attenuate more rapidly in the water
due to absorption than do lower frequency signals, thus producing only
a very small area of potential masking. If masking or communication
impairment were to occur briefly, it would more likely be in the
frequency range of MFAS (the more powerful source), which overlaps with
some odontocete vocalizations (but few mysticete vocalizations);
however, it would likely not mask the entirety of any particular
vocalization, communication series, or other critical auditory cue,
because the signal length, frequency, and duty cycle of the MFAS/HFAS
signal does not perfectly resemble the characteristics of any single
marine mammal species' vocalizations.
Other sources used in the Action Proponents' training and testing
that are not explicitly addressed above, many of either higher
frequencies (meaning that the sounds generated attenuate even closer to
the source) or used less frequently, would be expected to contribute to
masking over far smaller areas and/or times. For the reasons described
here, any limited masking that could potentially occur would be minor
and short-term.
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 Action
Proponents use are not expected to result in more than short-term, low
impact masking that will not affect reproduction or survival.
Auditory Injury From Sonar Acoustic Sources and Explosives and Non-
Auditory Injury From Explosives
Table 5 through table 13 indicate the number of takes of each
species by Level A harassment in the form of auditory injury resulting
from exposure to active sonar and/or explosives is estimated to occur,
and table 17 indicates the totals across all activities. The number of
takes estimated to result from auditory injury annually from sonar, air
guns, and explosives for each species/stock from all activities
combined ranges from 0 to 180 (the 180 is for the Western North
Atlantic stock of dwarf sperm whale). Nineteen stocks (all odontocetes)
have the potential to incur non-auditory injury from explosives, and
the number of individuals from any given stock from all activities
combined ranges from 1 to 3 (the 3 is for the Northern Gulf of America
stock of pantropical spotted dolphin). As described previously, the
Navy's model likely overestimates the number of injurious takes to some
degree. Nonetheless, these Level A harassment take numbers represent
the maximum number of instances in which marine mammals would be
reasonably expected to incur auditory and/or non-auditory injury, and
we have analyzed them accordingly.
If a marine mammal is able to approach a surface vessel within the
distance necessary to incur auditory injury in spite of the mitigation
measures, the likely speed of the vessel (nominally 10-15 kn (18.5-27.8
km/hr)) and relative motion of the vessel would make it very difficult
for the animal to remain in range long enough to accumulate enough
energy to result in more than a mild case of auditory injury. As
discussed previously in relation to TTS, the likely consequences to the
health of an individual that incurs auditory injury can range from mild
to more serious and is dependent upon the degree of auditory injury and
the frequency band associated with auditory injury. The majority of any
auditory injury incurred as a result of exposure to Navy sources would
be expected to be in the 2-20 kHz range (resulting from the most
powerful hull-mounted sonar) and could overlap a small portion of the
communication frequency range of many odontocetes, whereas other marine
mammal groups have communication calls at lower frequencies. Because of
the broadband nature of explosives, auditory injury incurred from
exposure to explosives would occur over a lower, but wider, frequency
range. Regardless of the frequency band, the more important point in
this case is that any auditory injury accrued as a result of exposure
to Navy activities would be expected to be of a small amount (single
digits). 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. 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.
The Action Proponents implement mitigation measures (described in
the 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
thereby improving the sightability of marine mammals and mitigation
effectiveness. Observing for marine mammals during the explosive
activities will include visual and passive acoustic detection methods
(the latter when they are available and part of the activity) before
the activity begins, in order to cover the mitigation zones that can
range from 200 yd (183 m) to 2,500 yd (2,286 m) depending on the source
(e.g., explosive sonobuoy, explosive torpedo, explosive bombs), and 2.5
nmi (4.6 km) for sinking exercises (see table 22 through table 31).
The type and amount of take by Level A harassment are indicated for
all species and species groups in table 50, table 52, table 54, table
56, table 58, and table 60. Generally speaking, non-auditory injuries
from explosives could range from minor lung injuries (the most
sensitive organ and first to be affected) that consist of some short-
term reduction of health and fitness immediately following the injury
that heals quickly and will not have any discernible long-term effects,
up to more impactful permanent injuries across multiple organs that may
cause health problems and negatively impact reproductive success (i.e.,
increase the time between pregnancies or even render reproduction
unlikely) but fall just short of a ``serious injury'' by virtue of the
fact that the animal is not expected to die. Nonetheless, due to the
Navy's mitigation and detection capabilities, we would not expect
marine mammals to typically be exposed to a more severe blast located
closer to the source--so the impacts likely would be less severe. In
addition, most non-auditory injuries and mortalities or serious
injuries are predicted for stocks with medium to large group sizes
(mostly delphinids), which increases sightability. It is still
difficult to evaluate how these injuries may or may not impact an
animal's fitness; however, these effects are seen only in very limited
numbers (single digits for all stocks) and mostly in species of
moderate, high, and very high abundances. In short, it is unlikely that
any, much less all, of the limited number of injuries accrued to any
one stock would result in reduced reproductive success of any
individuals. Even if a few injuries did result in
[[Page 50640]]
reduced reproductive success of individuals, the status of the affected
stocks are such that it would not be expected to adversely impact rates
of reproduction (and auditory injury of the low severity anticipated
here is not expected to affect the survival of any individual marine
mammals).
Serious Injury and Mortality
NMFS is authorizing a very limited number of serious injuries or
mortalities that could occur in the event of a vessel strike or as a
result of marine mammal exposure to explosive detonations (mostly
during ship shock trials). We note here that the takes from potential
vessel strikes or explosive exposures enumerated below could result in
non-serious injury, but their worst potential outcome (i.e., mortality)
is analyzed for the purposes of the negligible impact determination.
The MMPA requires that PBR be estimated in SARs and that it be used
in applications related to the management of take incidental to
commercial fisheries (i.e., the take reduction planning process
described in section 118 of the MMPA and the determination of whether a
stock is ``strategic'' as defined in section 3). While nothing in the
statute requires the application of PBR outside the management of
commercial fisheries interactions with marine mammals, NMFS recognizes
that as a quantitative metric, PBR may be useful as a consideration
when evaluating the impacts of other human-caused activities on marine
mammal stocks. Outside the commercial fishing context, and in
consideration of all known human-caused mortality, PBR can help inform
the potential effects of M/SI requested to be authorized under section
101(a)(5)(A). As noted by NMFS and the U.S. Fish and Wildlife Service
(Services) in our implementing regulations for the 1986 amendments to
the MMPA (54 FR 40341, September 29, 1989), the Services consider many
factors, when available, in making a negligible impact determination,
including, but not limited to: (1) the status of the species or stock
relative to optimum sustainable population (if known); (2) whether the
recruitment rate for the species or stock is increasing, decreasing,
stable, or unknown; (3) the size and distribution of the population;
and (4) existing impacts and environmental conditions. In this multi-
factor analysis, PBR can be a useful indicator for when, and to what
extent, the agency should take an especially close look at the
circumstances associated with the potential mortality, along with any
other factors that could influence annual rates of recruitment or
survival.
Below we describe how PBR is considered in NMFS M/SI analysis.
Please see the 2020 Northwest Training and Testing Final Rule (85 FR
72312, November 12, 2020) for a background discussion of PBR and how it
was adopted for use authorizing incidental take under section
101(a)(5)(A) for specified activities such as the Action Proponent's
training and testing in the AFTT Study Area.
When considering PBR during evaluation of effects of M/SI under
section 101(a)(5)(A), we utilize a two-tiered analysis for each stock
for which M/SI is proposed for authorization:
Tier 1: Compare the total human-caused average annual M/SI estimate
from all sources, including the M/SI proposed for authorization from
the specific activity, to PBR. If the total M/SI estimate is less than
or equal to PBR, then the specific activity is considered to have a
negligible impact on that stock. If the total M/SI estimate (including
from the specific activity) exceeds PBR, conduct the Tier 2 analysis.
Tier 2: Evaluate the estimated M/SI from the specified activity
relative to the stock's PBR. If the M/SI from the specified activity is
less than or equal to 10 percent of PBR and other major sources of
human-caused mortality have mitigation in place, then the individual
specified activity is considered to have a negligible impact on that
stock. If the estimate exceeds 10 percent of PBR, then, absent other
mitigating factors, the specified activity is considered likely to have
a non-negligible impact on that stock.
Additional detail regarding the two tiers of the evaluation is
provided below.
As indicated above, the goal of the Tier 1 assessment is to
determine whether total annual human-caused mortality, including from
the specified activity, would exceed PBR. To aid in the Tier 1
evaluation and get a clearer picture of the amount of annual M/SI that
remains without exceeding PBR, for each species or stock, we first
calculate a ``residual PBR,'' which equals PBR minus the ongoing annual
human-caused M/SI (i.e., Residual PBR = PBR-(annual M/SI estimate from
the SAR + other M/SI authorized under 101(a)(5)(A)). If the ongoing
human-caused M/SI from other sources does not exceed PBR, then residual
PBR is a positive number, and we consider how the authorized incidental
M/SI from the specified activities being evaluated compares to residual
PBR using the Tier 1 framework in the following paragraph. If the
ongoing anthropogenic mortality from other sources already exceeds PBR,
then residual PBR is a negative number and we move to the Tier 2
discussion further below to consider the M/SI from the specific
activities.
To reiterate the Tier 1 analysis overview in the context of
residual PBR, if the M/SI from the specified activity does not exceed
PBR, the impacts of the authorized M/SI on the species or stock are
generally considered to be negligible. As a simplifying analytical tool
in the Tier 1 evaluation, we first consider whether the M/SI from the
specified activities could cause incidental M/SI that is less than 10
percent of residual PBR, which we consider an ``insignificance
threshold.'' If so, we consider M/SI from the specified activities to
represent an insignificant incremental increase in ongoing
anthropogenic M/SI for the marine mammal stock in question that alone
will clearly not adversely affect annual rates of recruitment and
survival and for which additional analysis or discussion of the
anticipated M/SI is not required because the negligible impact standard
clearly will not be exceeded on that basis alone.
When the M/SI from the specified activity is above the
insignificance threshold in the Tier 1 evaluation, it does not indicate
that the M/SI associated with the specified activities is necessarily
approaching a level that would exceed negligible impact. Rather, it is
used as a cue to look more closely if and when the M/SI for the
specified activity approaches residual PBR, as it becomes increasingly
necessary (the closer the M/SI from the specified activity is to 100
percent residual PBR) to carefully consider whether there are other
factors that could affect reproduction or survival, such as take by
Level A and/or Level B harassment that has been predicted to impact
reproduction or survival of individuals, or other considerations such
as information that illustrates high uncertainty involved in the
calculation of PBR for some stocks. Recognizing that the impacts of
harassment of any authorized incidental take (by Level A or Level B
harassment from the specified activities) would not combine with the
effects of the authorized M/SI to adversely affect the stock through
effects on recruitment or survival, if the authorized M/SI for the
specified activity is less than residual PBR, the M/SI, alone, would be
considered to have a negligible impact on the species or stock. If the
authorized M/SI is greater than residual PBR, then the assessment
should proceed to Tier 2.
[[Page 50641]]
For the Tier 2 evaluation, recognizing that the total annual human-
caused M/SI exceeds PBR, we consider whether the incremental effects of
the authorized M/SI for the specified activity, specifically, would be
expected to result in a negligible impact on the affected species or
stocks. For the Tier 2 assessment, consideration of other factors
(positive or negative), including those described above (e.g., the
certainty in the data underlying PBR and the impacts of any harassment
authorized for the specified activity), as well as the mitigation in
place to reduce M/SI from other activities is especially important to
assessing the impacts of the M/SI from the specified activity on the
species or stock. PBR is a conservative metric and not sufficiently
precise to serve as an absolute predictor of population effects upon
which mortality caps would appropriately be based. For example, in some
cases stock abundance (which is one of three key inputs into the PBR
calculation) is underestimated because marine mammal survey data within
the U.S. EEZ are used to calculate the abundance even when the stock
range extends well beyond the U.S. EEZ. An underestimate of abundance
could result in an underestimate of PBR. Alternatively, we sometimes
may not have complete M/SI data beyond the U.S. EEZ to compare to PBR,
which could result in an overestimate of residual PBR. The accuracy and
certainty around the data that feed any PBR calculation, such as the
abundance estimates, must be carefully considered to evaluate whether
the calculated PBR accurately reflects the circumstances of the
particular stock.
Also, as referenced above, in some cases the ongoing human-caused
mortality from activities other than those being evaluated already
exceeds PBR and, therefore, residual PBR is negative. In these cases,
any additional mortality, no matter how small, and no matter how small
relative to the mortality caused by other human activities, would
result in greater exceedance of PBR. PBR is helpful in informing the
analysis of the effects of mortality on a species or stock because it
is important from a biological perspective to be able to consider how
the total mortality in a given year may affect the population. However,
section 101(a)(5)(A) of the MMPA indicates that NMFS shall authorize
the requested incidental take from a specified activity if we find that
``the total of such taking [i.e., from the specified activity] will
have a negligible impact on such species or stock.'' In other words,
the task under the statute is to evaluate the applicant's anticipated
take in relation to their take's impact on the species or stock, not
other entities' impacts on the species or stock. Neither the MMPA nor
NMFS' implementing regulations call for consideration of other
unrelated activities and their impacts on the species or stock.
Accordingly, we may find that the impacts of the taking from the
specified activity may (alone) be negligible even when total human-
caused mortality from all activities exceeds PBR (in the context of a
particular species or stock). Specifically, where the authorized M/SI
would be less than or equal to 10 percent of PBR and management
measures are being taken to address M/SI from the other contributing
activities (i.e., other than the specified activities covered by the
incidental take authorization under consideration), the impacts of the
authorized M/SI would be considered negligible. In addition, we must
also still determine that any impacts on the species or stock from
other types of take (i.e., harassment) caused by the applicant do not
combine with the impacts from mortality or serious injury addressed
here to result in adverse effects on the species or stock through
effects on annual rates of recruitment or survival.
As noted above, while PBR is useful in informing the evaluation of
the effects of M/SI in section 101(a)(5)(A) determinations, it is one
consideration to be assessed in combination with other factors and is
not determinative. For example, as explained above, the accuracy and
certainty of the data used to calculate PBR for the species or stock
must be considered. And we reiterate the considerations discussed above
for why it is not appropriate to consider PBR an absolute cap in the
application of this guidance. Accordingly, we use PBR as a trigger for
concern while also considering other relevant factors to provide a
reasonable and appropriate means of evaluating the effects of potential
mortality on rates of recruitment and survival, while acknowledging
that it is possible for total human-caused M/SI to exceed PBR (or for
the M/SI from the specified activity to exceed 10 percent of PBR in the
case where other human-caused mortality is exceeding PBR, as described
in the last paragraph) by some small amount and still make a negligible
impact determination under section 101(a)(5)(A).
We note that on June 17, 2020, NMFS finalized new Criteria for
Determining Negligible Impact under MMPA section 101(a)(5)(E). The
guidance explicitly notes the differences in the negligible impact
determinations required under paragraph (a)(5)(E) of section 101, as
compared to paragraphs (a)(5)(A) and (D) of section 101, and specifies
that the procedure in that document is limited to how the agency
conducts negligible impact analyses for commercial fisheries under
section 101(a)(5)(E). In this rule, NMFS has described its method for
considering PBR to evaluate the effects of potential mortality in the
negligible impact analysis. NMFS has reviewed the 2020 guidance and
determined that our consideration of PBR in the evaluation of mortality
as described above and in the rule remains appropriate for use in the
negligible impact analysis for the Action Proponents' activities under
section 101(a)(5)(A).
Our evaluation of the M/SI for each of the species and stocks for
which mortality or serious injury could occur follows.
We first consider maximum potential incidental M/SI from the Action
Proponents' vessel strike analysis for the affected large whales (table
47) and from the Action Proponents' explosive detonations for the
affected small cetaceans (table 48) in consideration of NMFS' threshold
for identifying insignificant M/SI take. By considering the maximum
potential incidental M/SI in relation to PBR and ongoing sources of
anthropogenic mortality, as described above, we begin our evaluation of
whether the potential incremental addition of M/SI through vessel
strikes and explosive detonations may affect the species' or stocks'
annual rates of recruitment or survival. We also consider the
interaction of those mortalities with incidental taking of that species
or stock by harassment pursuant to the specified activity.
Based on the methods discussed previously, NMFS is authorizing six
mortalities of large whales due to vessel strike over the course of the
7-year rule, three by each Action Proponent. Across the 7-year duration
of the rule, two takes by mortality (annual average of 0.29 takes) of
fin whale (Western North Atlantic stock), minke whale (Canadian East
Coast stock), sei whale (Nova Scotia stock), and sperm whale (North
Atlantic stock) could occur and are authorized (table 47); one take by
mortality (annual average of 0.14 takes) of the Northern Gulf of
America stock of sperm whale could occur and is authorized; four takes
by mortality (annual average of 0.57 takes) of humpback whale (Gulf of
Maine stock) could occur and are authorized (table 47). To calculate
the annual average of M/SI by vessel strike,
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we divided the 7-year take by serious injury or mortality by seven.
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The Action Proponents also requested a limited number of takes by
M/SI from explosives. Across the 7-year duration, NMFS is authorizing
five takes by M/SI (annual average of 0.71 takes) of pantropical
spotted dolphin (Northern
[[Page 50644]]
Gulf of America stock), two takes by M/SI (annual average of 0.29
takes) of striped dolphin (Northern Gulf of America stock), two takes
by M/SI (annual average of 0.29 takes) of bottlenose dolphin (Western
North Atlantic Offshore stock), one take by M/SI (annual average of
0.14 takes) of Tamanend's bottlenose dolphin (Western North Atlantic
South Carolina/Georgia Coastal), and three takes by M/SI (annual
average of 0.43 takes) of Clymene dolphin (Western North Atlantic
stock) (table 48). To calculate the annual average of M/SI from
explosives, we divided the 7-year take by serious injury or mortality
by seven (table 48), the same method described for vessel strikes.
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As described above, NMFS M/SI analysis includes two tiers and our
discussion is organized into sections that mirror that framework, as
[[Page 50646]]
applicable. Specifically, we standardly first address stocks analyzed
within Tier 1 (i.e., those for which total known human-caused M/SI is
below PBR (i.e., the M/SI from the specified activity is below residual
PBR)), considering those with proposed M/SI both below and above the
insignificance threshold. Then, if applicable, we discuss stocks for
which total mortality exceeds PBR in a Tier 2 analysis in which we
compare the proposed M/SI of the specified activity alone against PBR
and consider other factors as necessary. Of note, for some stocks total
M/SI is not known, in which case a Tier 1 analysis is not possible and,
therefore, we move directly to a Tier 2 analysis. In rare cases, PBR
itself cannot be calculated, in which case we consider other known
factors and/or surrogate stocks to inform the NID analysis.
Stocks With Total Average Annual Human-Caused M/SI Below PBR (Tier 1)
and Authorized M/SI From the Specified Activity Is Below the
Insignificance Threshold--
As noted above, for a species or stock with authorized M/SI less
than 10 percent of residual PBR, we consider M/SI from the specified
activities to represent an insignificant incremental increase in
ongoing anthropogenic M/SI that alone (i.e., in the absence of any
other take and barring any other unusual circumstances) will clearly
not adversely affect annual rates of recruitment and survival. In this
case, as shown in table 47 and table 48, the following species or
stocks have potential for estimated take by M/SI from vessel strike and
explosives, respectively, and authorized below their insignificance
threshold: fin whale (Western North Atlantic stock); humpback whale
(Gulf of Maine stock); minke whale (Canadian East Coast stock); sei
whale (Nova Scotia stock); sperm whale (North Atlantic stock);
pantropical spotted dolphin (Northern Gulf of America Stock);
bottlenose dolphin (Western North Atlantic Offshore); Tamanend's
bottlenose dolphin (Western North Atlantic South Carolina/Georgia
Coastal Stock); Clymene dolphin (Western North Atlantic Stock). While
the authorized M/SI of humpback whales (Gulf of Maine stock) and minke
whales (Canadian East Coast stock) are each below the insignificance
threshold, because of the current UMEs, we further address how the
authorized M/SI and the UMEs inform the negligible impact
determinations immediately below. For the other seven stocks with
authorized M/SI below the insignificance threshold, there are no other
known factors, information, or unusual circumstances that indicate
anticipated M/SI below the insignificance threshold could have adverse
effects on annual rates of recruitment or survival and they are not
discussed further. For the remaining stocks with potential M/SI above
the insignificance threshold, how that M/SI compares to residual PBR,
as well as additional factors, are discussed below as well.
Humpback Whale (Gulf of Maine Stock)
For this stock, PBR is currently set at 22. The total annual M/SI
from other sources of anthropogenic mortality is estimated to be 12.15.
This yields a residual PBR of 9.85. The additional 0.57 annual
mortalities that are authorized in this rule are below the
insignificance threshold (10 percent of residual PBR, in this case
0.985). Nonetheless, since January 2016, elevated humpback whale
mortalities have occurred along the Atlantic coast from Maine to
Florida. As of September 4, 2025, there have been 257 known strandings,
and of the whales examined, about 40 percent had evidence of human
interaction either from vessel strike or entanglement. NOAA is
consulting with researchers that are conducting studies on the humpback
whale populations, and these efforts may provide information on changes
in whale distribution and habitat use that could provide additional
insight into how these vessel interactions occurred. However, even in
consideration of the UME, the incremental increase in annual mortality
from the Action Proponents' specified activities is not expected to
adversely affect annual rates of recruitment or survival.
Minke Whale (Canadian East Coast Stock)
For this stock, PBR is currently set at 170. The total annual M/SI
from other sources of anthropogenic mortality is estimated to be 9.4.
In addition, 1 annual mortality has been authorized for this same stock
in the current incidental take regulations for NMFS' Northeast
Fisheries Science Center (86 FR 58434, October 21, 2021). This yields a
residual PBR of 159.6. The additional 0.29 annual mortalities that are
authorized in this rule are well below the insignificance threshold (10
percent of residual PBR, in this case 16.0). Nonetheless, minke whale
mortalities detected along the Atlantic coast from Maine through South
Carolina resulted in the declaration of an on-going UME in 2017.
Preliminary findings show evidence of human interactions or infectious
disease, but these findings are not consistent across all of the minke
whales examined, so more research is needed. As of September 4, 2025, a
total of 205 minke whales have stranded during this UME, averaging
about 25 animals per year. However, even in consideration of the UME,
the incremental increase in annual mortality from the Action
Proponents' activities is not expected to adversely affect annual rates
of recruitment or survival.
Stocks With Total Average Human-Caused M/SI Above PBR (Tier 2))--
Sperm Whale (Northern Gulf of America Stock)
For the Northern Gulf of America stock of sperm whale, PBR is
currently set at 2 and the total annual M/SI is estimated at 9.6,
yielding a residual PBR of -7.6. This rule authorizes 1 M/SI (Navy
only) over the 7-year duration of the rule (indicated as 0.14 annually
for the purposes of comparing to PBR and evaluating overall effects on
annual rates of recruitment and survival), which means that residual
PBR is exceeded by 7.74. However, as described above, given that the
negligible impact determination is based on the assessment of take of
the activity being analyzed, when total annual mortality from human
activities is higher, but the impacts from the specific activity being
analyzed are very small, NMFS may still find the impact of the
authorized take from a specified activity to be negligible even if
total human-caused mortality exceeds PBR (specifically if the
authorized mortality is less than 10 percent of PBR and management
measures are being taken to address serious injuries and mortalities
from the other activities causing mortality (i.e., other than the
specified activities covered by the incidental take authorization in
consideration)). When those considerations are applied here, the
authorized lethal take (0.14 annually) of the Northern Gulf of America
stock of sperm whale is less than 10 percent of PBR (PBR is 2).
Additionally, there are management measures in place to address M/SI
from activities other than those the Action Proponents are conducting
(as discussed below). Immediately below, we explain the information
that supports our finding that the M/SI authorized by this rule is not
expected to result in more than a negligible impact on this stock. As
described previously, NMFS must also ensure that impacts by the
applicant on the species or stock from other types of take (i.e.,
harassment) do not combine with the impacts from mortality to adversely
affect the species or stock via
[[Page 50647]]
impacts on annual rates of recruitment or survival, which we have done
further below in the stock-specific conclusion sections.
As discussed, we also take into consideration management measures
in place to address M/SI caused by other activities. As reported in the
SAR, of the total annual M/SI of this stock (9.6), 9.4 of those M/SI
are from the DWH oil spill. (The remaining 0.2 are fishery-related M/
SI.) Since the DWH spill, there have been numerous recovery efforts for
marine mammals. The DWH oil spill Natural Resource Damage Assessment
(NRDA) settlement allocated $144,000,000 to marine mammal restoration,
and as of 2021, $30,968,016 has been allocated (DWH NRDA Trustees,
2021). Projects have focused on understanding and assessing Gulf
cetacean populations, enhancing the capacity of stranding and response
programs, enhancing our understanding of, and reducing, stressors on
cetaceans, and developing and implementing decision support tools for
cetaceans. Recovery efforts have included some efforts to minimize
impacts to marine mammals from ocean noise. Proposals and planning for
additional pilot projects, including projects to test existing
alternatives to traditional airgun seismic surveys, engineering
solutions for vessel quieting, and operational approaches for quieting
commercial vessels while underway (Southall et al., 2024b).
In this case, 0.14 M/SI means one mortality in 1 of the 7 years and
zero mortalities in 6 of those 7 years. Therefore, the Action
Proponents would not be contributing to the total human-caused
mortality at all in 6 of the 7, or 85.7 percent, of the years covered
by this rulemaking. That means that even if a Northern Gulf of America
stock of sperm whale were to be taken by mortality from vessel strike,
in 6 of the 7 years there could be no effect on annual rates of
recruitment or survival from Action Proponent-caused M/SI.
Additionally, the loss of a male would have far less, if any, effect on
population rates and absent any information suggesting that one sex is
more likely to be struck than another, we can reasonably assume that
there is a 50 percent chance that the single strike authorized by this
rulemaking would be a male, thereby further decreasing the likelihood
of impacts on the population rate. In situations like this where
potential M/SI is fractional, consideration must be given to the
lessened impacts anticipated due to the absence of M/SI in 6 of the 7
years and the fact that the single strike could be a male. Lastly, we
reiterate that PBR is a conservative metric and also not sufficiently
precise to serve as an absolute predictor of population effects upon
which mortality caps would appropriately be based. This is especially
important given the minor difference between zero and one across the 7-
year period covered by this rulemaking, which is the smallest
distinction possible when considering mortality. As noted above, Wade
et al. (1998) (authors of the paper from which the current PBR equation
is derived) note, ``Estimating incidental mortality in 1 year to be
greater than the PBR calculated from a single abundance survey does not
prove the mortality will lead to depletion; it identifies a population
worthy of careful future monitoring and possibly indicates that
mortality-mitigation efforts should be initiated.'' Importantly, M/SI
authorized by this rule is below 10 percent of PBR, and management
actions are in place to support recovery of the stock following the DWH
oil spill impacts. Based on the presence of the factors described
above, we do not expect lethal take from Navy activities, alone, to
adversely affect Northern Gulf of America stock of sperm whales through
effects on annual rates of recruitment or survival. Nonetheless, the
fact that total human-caused mortality exceeds PBR necessitates close
attention to the remainder of the impacts (i.e., harassment) on the
Northern Gulf of America stock of sperm whale from the Action
Proponents' activities to ensure that the total authorized takes have a
negligible impact on the species or stock. Therefore, this information
will be considered in combination with our assessment of the impacts of
authorized harassment takes in the Group and Species-Specific Analyses
section that follows.
Striped Dolphin (Northern Gulf of America Stock)
For striped dolphin (Northern Gulf of America stock), PBR is
currently set at 12 and the total annual M/SI is estimated at greater
than or equal to 13. As described in the SAR, these 13 M/SI are
predicted M/SI from the DWH oil spill. In addition, 0.6 annual
mortalities have been authorized for this same stock in the current
incidental take regulations for NMFS' Southeast Fisheries Science
Center (85 FR 27028, May 6, 2020). This yields a residual PBR of -1.6.
This rule authorizes two M/SI for the Navy over the 7-year duration of
the rule (indicated as 0.29 annually for the purposes of comparing to
PBR and evaluating overall effects on annual rates of recruitment and
survival), which means that residual PBR is exceeded by 1.89. However,
as described above, given that the negligible impact determination is
based on the assessment of take of the activity being analyzed, when
total annual mortality from human activities is higher, but the impacts
from the specific activity being analyzed are very small, NMFS may
still find the impact of the authorized take from a specified activity
to be negligible even if total human-caused mortality exceeds PBR--
specifically if the authorized mortality is less than 10 percent of PBR
and management measures are being taken to address serious injuries and
mortalities from the other activities causing mortality (i.e., other
than the specified activities covered by the incidental take
authorization in consideration). When those considerations are applied
here, the authorized lethal take (0.29 annually) of Northern Gulf of
America stock of striped dolphin is less than 10 percent of PBR (PBR is
12). Additionally, there are management measures in place to address M/
SI from activities other than those the Action Proponents are
conducting (as discussed below). Immediately below, we explain the
information that supports our finding that the M/SI authorized by this
rule is not expected to result in more than a negligible impact on this
stock. As described previously, NMFS must also ensure that impacts by
the applicant on the species or stock from other types of take (i.e.,
harassment) do not combine with the impacts from mortality to adversely
affect the species or stock via impacts on annual rates of recruitment
or survival, which we have done further below in the stock-specific
conclusion sections.
As discussed, we also take into consideration management measures
in place to address M/SI caused by other activities. As reported in the
SAR, all 13 of the total annual M/SI of this stock are from the DWH oil
spill. As described in the previous section in more detail, since the
DWH spill, there have been numerous recovery efforts for marine
mammals, including some efforts to minimize impacts to marine mammals
from ocean noise, such as pilot projects to test existing alternatives
to traditional airgun seismic surveys, engineering solutions for vessel
quieting, and operational approaches for quieting commercial vessels
while underway (Southall et al. 2024b).
Additionally of note, in this case, 0.29 M/SI means zero
mortalities in at least 5 of the 7 years that would be covered by this
authorization. Therefore, the Action Proponents would not be
contributing to the total human-caused
[[Page 50648]]
mortality at all in 5 of the 7, or 71.4 percent, of the years covered
by this rulemaking. That means that even if two striped dolphins were
to be taken by mortality from explosives, in 5 of the 7 years there
could be no effect on annual rates of recruitment or survival from
Action Proponent-caused M/SI. Additionally, the loss of a male would
have far less, if any, effect on population rates and absent any
information suggesting that one sex is more likely to be taken than
another, we can reasonably assume that one of the mortalities
authorized by this rulemaking would be a male, thereby further
decreasing the likelihood of impacts on the population rate. In
situations like this where potential M/SI is fractional, consideration
must be given to the lessened impacts anticipated due to the absence of
M/SI in 6 of the 7 years and the fact that the single strike could be a
male. Lastly, we reiterate that PBR is a conservative metric and also
not sufficiently precise to serve as an absolute predictor of
population effects upon which mortality caps would appropriately be
based. This is especially important given the minor difference between
zero and one across the 7-year period covered by this rulemaking, which
is the smallest distinction possible when considering mortality. As
noted previously, Wade et al. (1998) state, ``Estimating incidental
mortality in 1 year to be greater than the PBR calculated from a single
abundance survey does not prove the mortality will lead to depletion;
it identifies a population worthy of careful future monitoring and
possibly indicates that mortality-mitigation efforts should be
initiated.'' Further, M/SI authorized by this rule is below 10 percent
of PBR, and management actions are in place to support recovery of the
stock following the DWH oil spill impacts. Based on the presence of the
factors described above, we do not expect lethal take from Navy
activities, alone, to adversely affect Northern Gulf of America stock
of striped dolphins through effects on annual rates of recruitment or
survival. Nonetheless, the fact that total human-caused mortality
exceeds PBR necessitates close attention to the remainder of the
impacts (i.e., harassment) on the Northern Gulf of America stock of
striped dolphins from the Action Proponents' activities to ensure that
the total authorized takes have a negligible impact on the species or
stock. Therefore, this information will be considered in combination
with our assessment of the impacts of authorized harassment takes in
the Group and Species-Specific Analyses section that follows.
Deepwater Horizon Oil Spill
As discussed in the Deepwater Horizon Oil Spill section of the
proposed rule, the DWH oil spill caused a suite of adverse health
effects to marine mammals in the Gulf of America. Coastal and estuarine
bottlenose dolphin populations were some of the most severely injured
(Hohn et al., 2017; Rosel et al., 2017; Thomas et al., 2017), but
oceanic species were also exposed and experienced increased mortality,
increased reproductive failure, and a higher likelihood of other
adverse health effects.
Due to the scope of the DWH oil spill, the magnitude of potentially
injured populations, and the difficulties and limitations of working
with marine mammals, it is impossible to quantify injury without
uncertainty. Wherever possible, the quantification results represent
ranges of values that encapsulate the uncertainty inherent in the
underlying datasets. The population model outputs shown in table 49
best represent the temporal magnitude of the injury and the potential
recovery time from the injury (DWH NRDA Trustees, 2016). The values in
the table inform the baseline levels of both individual health and
susceptibility to additional stressors, as well as stock status, with
which the effects of the Action Proponents' takes are considered in the
negligible impact analysis. Additionally, estimates of annual mortality
for many stocks now include mortality attributed to the effects of the
DWH oil spill (see table 49) (Hayes et al., 2024), and these mortality
estimates are considered as part of the environmental baseline.
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Group and Species-Specific Analyses
In this section, we build on the general analysis that applies to
all marine mammals in the AFTT Study Area from the previous sections.
We first include information and analysis that applies to mysticetes
or, separately, odontocetes, or pinnipeds, and then within those three
sections, more specific information that applies to smaller groups,
where applicable, and the affected species or stocks. The specific
authorized take numbers are also included in the analyses below, so
here we provide some additional context and discussion regarding how we
consider the authorized take numbers in those analyses.
The maximum amount and type of incidental take of marine mammals
reasonably likely to occur and therefore authorized from exposures to
sonar and other active acoustic sources and explosions during the 7-
year activity period are shown in table 2, table 3, and table 4, and
the subset attributable to ship shock trials is included in table 12.
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 Level A harassment takes are far more
likely to be associated with separate individuals), and in some cases
individuals may be taken more than one time. As part of our evaluation
of the magnitude and severity of impacts to marine mammal individuals
and the species, and specifically in an effort to better understand the
degree to which the modeled and estimated takes likely represent
repeated takes of the individuals of a given species/stock, we consider
the total annual numbers of take by harassment (AUD INJ, non-auditory
injury, TTS, and behavioral disturbance) for species or stocks as
compared to their associated abundance estimates--specifically, take
numbers higher than the stock abundance clearly indicate that some
number of individuals are being taken on more than 1 day in the year,
and broadly higher or lower ratios of take to abundance may reasonably
be considered to equate to higher or lower likelihood of repeated
takes, respectively, other potentially influencing factors being equal.
In addition to the mathematical consideration of estimated take
compared to abundance, we also consider other factors or circumstances
that may influence the likelihood of repeated takes, where known, such
as circumstances where activities resulting in take are focused in an
area and time (e.g., instrumented ranges or a homeport, or long-
duration activities such as MTEs) and/or where the same individual
marine mammals are known to congregate over longer periods of time
(e.g., pinnipeds at a haulout, mysticetes in a known foraging area, or
resident odontocetes with smaller home ranges). Similarly, and all else
being equal, estimated takes that are largely focused in one region
and/or season (see appendix A of the application and table 50, table
52, table 54, table 56, table 58, and table 60 of this final rule) may
indicate a higher likelihood of repeated takes of the same individuals.
Occasional, milder behavioral responses are unlikely to cause long-
term consequences for individual animals or populations, and even if
some smaller subset of the takes is in the form of a longer (several
hours or a day) and more severe response, if they are not expected to
be repeated over a comparatively longer duration of 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., 2018; King et al., 2015; NAS 2017; New et
al., 2014; Southall et al., 2007; Villegas-Amtmann et al., 2015;
Hoekendijk et al., 2018; Wisniewska et al., 2018; Czapanskiy et al.,
2021; Pirotta, 2022). Generally speaking, and in the case of most
species impacted by the planned activities, in the cases where some
number of individuals may reasonably be expected to be taken on more
than 1 day within a year, that number of days would be comparatively
small and also with no reason to expect that those takes would occur on
sequential days. In the rarer cases of species where individuals might
be expected to be taken on a comparatively higher number of days of the
year and there are reasons to think that these days might be sequential
or clumped together, the likely impacts of this situation are discussed
explicitly in the species discussions.
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 AUD INJ or TTS may sometimes, for example, also
be subject to behavioral disturbance at the same time. As described
above in this section, the degree of auditory injury, 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 accrues auditory injury or TTS and
is also subjected to behavioral disturbance would result in impacts to
reproduction or survival. Alternately, we recognize that if an
individual is subjected to behavioral disturbance repeatedly for a
longer duration and on consecutive days, effects could accrue to the
point that reproductive success is impacted. Accordingly, in analyzing
the number of takes and the likelihood of repeated and sequential
takes, we consider the total takes, not just the takes by Level B
harassment by behavioral disturbance, so that individuals potentially
exposed to both threshold shift and behavioral disturbance are
appropriately considered. The number of takes by Level A harassment by
AUD INJ are so low (and zero in some cases) compared to abundance
numbers that it is considered highly unlikely that any individual would
be taken at those levels more than once.
Use of sonar and other transducers would typically be transient and
temporary. The majority of acoustic effects to most marine mammal
stocks from sonar and other active sound sources during the specified
military readiness activities would be primarily from anti-submarine
warfare events. 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
expected to occur infrequently. In addition to the proximity to the
source, the type of activity and the season and location during which
an animal is exposed can inform the impacts. These factors, including
the numbers and types of effects that are estimated in areas known to
be biologically important for certain species are discussed in the
group and species-specific sections, below.
Further, as described in the Mitigation Measures section, this rule
includes mitigation measures that would reduce the probability and/or
severity of
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impacts expected to result from acute exposure to acoustic sources or
explosives, vessel strike, and impacts to marine mammal habitat.
Specifically, the Action Proponents would use a combination of delayed
starts, powerdowns, and shutdowns to avoid mortality or serious injury,
minimize the likelihood or severity of AUD INJ or non-auditory injury,
and reduce instances of TTS or more severe behavioral disturbance
caused by acoustic sources or explosives. The Action Proponents would
also implement multiple time/area restrictions that would reduce take
of marine mammals in areas or at times where they are known to engage
in important behaviors, such as calving, where the disruption of those
behaviors would have a higher probability of resulting in impacts on
reproduction or survival of individuals that could lead to population-
level impacts.
These time/area restrictions include ship shock trial mitigation
areas throughout the AFTT Study Area, MTE Planning Awareness Mitigation
Areas in the Northeast and Mid-Atlantic, a Gulf of Maine Marine Mammal
Mitigation Area, several mitigation areas specific to NARW, and a
Rice's Whale Mitigation Area. Mitigation areas for NARW and Rice's
whale specifically are discussed in those species-specific sections
below. However, it is important to note that measures in those areas,
while developed to protect those species, would also benefit other
marine mammals in those areas.
Regarding ship shock trials, the Action Proponents will not conduct
ship shock trials within the Rice's whale core distribution area in the
northern Gulf of America or within the portion of the ship shock trial
box that overlaps the Jacksonville OPAREA from November 15 through
April 15. These mitigation measures would avoid potential exposure of
Rice's whales to injurious levels of sound and avoid potential
injurious and behavioral impacts to NARW during calving season.
Additionally, pre-event planning for ship shock trials will include the
selection of sites where marine mammal abundance is expected to be the
lowest during the planned event and prioritize sites more than 2 nmi
(3.7 km) from the western boundary of the Gulf Stream where marine
mammals would be expected in greater concentrations for foraging and
migration. Overall, the benefits of Ship Shock Trial Mitigation Areas
would be substantial for all marine mammal taxa because ship shock
trials use the largest NEW of any explosive activity conducted in the
AFTT Study Area.
Regarding MTEs, the Action Proponents will not conduct any MTEs or
any portion of any MTE in the Major Training Exercise Planning
Awareness Mitigation Areas in the northeast. This would restrict MTEs
from occurring within NARW foraging critical habitat, on Georges Bank,
and in areas that contain underwater canyons (e.g., Hydrographer
Canyon, and a portion of the Northeast Canyons and Seamounts National
Marine Monument), as these locations have been associated with high
marine mammal abundance, feeding, and mating. In the Major Training
Exercise Planning Awareness Mitigation Areas in the mid-Atlantic, the
Action Proponents will not conduct any MTEs or any portion of any MTE
to the maximum extent practicable and would conduct no more than four
(or a portion of more than four) MTEs per year. This would restrict the
number of MTEs that could occur within large swaths of shelf break that
contain underwater canyons or other habitats (e.g., Norfolk Canyon,
part of the Cape Hatteras Special Research Area) associated with high
marine mammal diversity in this region.
In the Gulf of Maine Marine Mammal Mitigation Area, the Action
Proponents would use no more than 200 hours of surface ship hull-
mounted MFAS annually. This measure is designed to reduce exposure of
marine mammals to potentially injurious levels of sound from surface
ship hull-mounted MFAS, the type of active sonar with the highest power
source used in the AFTT Study Area.
Additionally, the Action Proponents would implement four mitigation
areas specifically designed to protect NARW. These include the
Northeast North Atlantic Right Whale Mitigation Area, Jacksonville
Operating Area North Atlantic Right Whale Mitigation Area, Southeast
North Atlantic Right Whale Mitigation Area, and the Dynamic North
Atlantic Right Whale Mitigation Area. These areas are designed to
reduce exposure of NARWs to acoustic and explosive stressors as well as
vessel strike risk in foraging critical habitat, reproduction critical
habitat, and in areas and times when the species has a higher
occurrence in these areas. The Northeast North Atlantic Right Whale
Mitigation Area would also protect other marine mammal species,
including those with BIAs that overlap the mitigation area, including
fin whale, humpback whale, minke whale, sei whale, and harbor porpoise
(LaBrecque et al., 2015).
In addition to the nature and context of the disturbance, including
whether take occurs in a known BIA, species-specific factors affect the
severity of impacts to individual animals and population consequences
of disturbance. Keen et al. (2021) identify three population
consequences of disturbance themes: life history traits, environmental
conditions, and disturbance source characteristics. Life history traits
considered in Keen et al. (2021) include movement ecology (whether
animals are resident, nomadic, or migratory), reproductive strategy
(capital breeders, income breeders, or mixed), body size (based on size
and life stage), and pace of life (slow or fast).
Regarding movement ecology, resident animals that have small home
ranges relative to the size and duration of an impact zone have a
higher risk of repeated exposures to an ongoing activity. Animals that
are nomadic over a larger range may have less predictable risk of
repeated exposure. For resident and nomadic populations, overlap of a
stressor with feeding or reproduction depends more on time of year
rather than location in their habitat range. In contrast, migratory
animals may have higher or reduced potential for exposure during
feeding and reproduction based on both location, time of the year, and
duration of an activity. The risk of repeated exposure during
individual events may be lower during migration as animals maintain
directed transit through an area.
Reproduction is energetically expensive for female marine mammals,
and reproductive strategy can influence an animal's sensitivity to
disturbance. Mysticetes, with the exception of Bryde's whales and
Rice's whales, and phocids are capital breeders. Capital breeders rely
on their capital, or energy stores, to migrate, maintain pregnancy, and
nurse a calf. Capital breeders would be more resilient to short-term
foraging disruption due to their reliance on built-up energy reserves
but are vulnerable to prolonged foraging impacts during gestation.
Bryde's whales, Rice's whales, otariids, and most odontocetes are
income breeders, which rely on some level of income, or regular
foraging, to give birth and nurse a calf. Income breeders would be more
sensitive to the consequences of disturbances that impact foraging
during lactation. Some species exhibit traits of both, such as beaked
whales.
Smaller animals require more food intake per unit body mass than
large animals. They must consume food on a regular basis and are likely
to be non-migratory and income breeders. The smallest odontocetes, the
porpoises, must maintain high metabolisms to maintain thermoregulation
and cannot rely on blubber stores for long periods
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of time, whereas larger odontocetes can more easily thermoregulate. The
larger size of other odontocetes is an adaptation for deep diving that
allows them to access high quality mesopelagic and bathypelagic prey.
Both small and large odontocetes have lower foraging efficiency than
the large whales. The filter-feeding large whales (mysticetes) consume
most of their food within several months of the year and rely on
extensive lipid reserves for the remainder of the year. The metabolism
of mysticetes allows for fasting while seeking prey patches during
foraging season and prolonged periods of fasting outside of foraging
season (Goldbogen et al., 2023). Their energy stores support capital
breeding and long migrations. The effect of a temporary feeding
disturbance is likely to have inconsequential impacts to a mysticete
but may be consequential for small cetaceans. Despite their relatively
smaller size, amphibious pinnipeds have lower thermoregulatory
requirements because they spend a portion of time on land. For purposes
of this assessment, marine mammals were generally categorized as small
(less than 10 ft (3.05 m)), medium (10-30 ft (3.05-9.1 m)), or large
(more than 30 ft (9.1 m)) based on length.
Populations with a fast pace of life are characterized by early age
of maturity, high birth rates, and short life spans, whereas
populations with a slow pace of life are characterized by later age of
maturity, low birth rates, and long life spans. The consequences of
disturbance in these populations differ. Although reproduction in
populations with a fast pace of life is more sensitive to foraging
disruption, these populations are quick to recover. Reproduction in
populations with a slow pace of life is resilient to foraging
disruption, but late maturity and low birth rates mean that long-term
impacts to breeding adults have a longer-term effect on population
growth rates. Pace of life was categorized for each species in this
analysis by comparing age at sexual maturity, birth rate interval, life
span, body size, and feeding and reproductive strategy.
Southall et al. (2023) also identified factors that inform a
population's vulnerability. The authors describe a framework to assess
risk to populations from specific industry impact scenarios at
different locations or times of year. While this approach may not be
suitable for many military readiness activities, for which alternate
spatial or seasonal scenarios are not usually feasible, the concepts
considered in that framework's population vulnerability assessment are
useful in this analysis, including population status (e.g., endangered
or threatened), population trend (i.e., decreasing, stable, or
increasing), population size, and chronic exposure to other
anthropogenic or environmental stressors (e.g., fisheries interactions,
pollution). These factors are also considered when assessing the
overall vulnerability of a stock to repeated effects from acoustic and
explosive stressors.
In consideration of the factors outlined above, if impacts to
individuals increase in magnitude or severity such that repeated and
sequential higher severity impacts occur (the probability of this goes
up for an individual the higher total number of takes it has) or the
total number of moderate to more severe impacts increases
substantially, especially if occurring across sequential days, then it
becomes more likely that the aggregate effects could potentially
interfere with feeding enough to reduce energy budgets in a manner that
could impact reproductive success via longer cow-calf intervals,
terminated pregnancies, or calf mortality. It is important to note that
these impacts accrue exclusively to females, which comprise only
approximately 50 percent of the population. Based on energetic models,
it takes energetic impacts of a significantly greater magnitude to
cause the death of an adult marine mammal, and females will always
terminate a pregnancy or stop lactating before allowing their health to
deteriorate. Also, the death of an adult female has significantly more
impact on population growth rates than reductions in reproductive
success, while the death of an adult male has very little effect on
population growth rates. However, as explained earlier, such severe
impacts from the specified activities would be very infrequent and not
considered likely to occur at all for most species and stocks. We note
that the negligible impact analysis is inherently a two-tiered
assessment that first evaluates the anticipated impacts of the
activities on marine mammals individuals, and then if impacts are
expected to reproduction or survival of any individuals further
evaluates the effects of those individual impacts on rates of
reproduction and survival of the species or stock, in the context of
the status of the species or stock. The analyses below in some cases
address species collectively if they occupy the same functional hearing
group (i.e., VLF, LF, HF, and VHF cetaceans), share similar life
history strategies, and/or are known to behaviorally respond similarly
to acoustic 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 specified
activities on each affected species or stock even where discussion is
organized by functional hearing group and/or information is evaluated
at the group level. Where there are meaningful differences between a
species or stock that would further differentiate the analysis, they
are either described within the section or the discussion for those
species or stocks 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 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 stocks will incur, the applicable mitigation for each stock,
and the status and life history of the stocks to support the negligible
impact determinations for each stock. We have already described above
why we believe the incremental addition of the limited number of low-
level auditory injury takes will not have any meaningful effect towards
inhibiting reproduction or survival. We have also described above in
this section the unlikelihood of any masking or habitat impacts having
effects that would impact the reproduction or survival of any of the
individual marine mammals affected by the Action Proponents'
activities. For mysticetes, there is no predicted non-auditory injury
from explosives for any stock. Regarding the severity of individual
takes by Level B harassment by behavioral disturbance for mysticetes,
the majority of these responses are anticipated to occur at received
levels below 172 dB, and last from a few minutes to a few hours, at
most, with associated responses most likely in the form of moving away
from the source, foraging interruptions, vocalization changes, or
disruption of other social behaviors, lasting from a few minutes to
several hours. Much of the discussion below focuses on the behavioral
effects and the mitigation measures that reduce the probability or
severity of effects in BIAs or other habitat. Because there are
multiple stock-specific factors in relation to the status of the
species, as well as mortality take for several stocks,
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at the end of the section we break out stock-specific findings.
In table 50 below for mysticetes, we indicate the total annual
mortality, Level A harassment, and Level B harassment, and the maximum
annual harassment as a percentage of stock abundance.
In table 51 below, we indicate the status, life history traits,
important habitats, and threats that inform our analysis of the
potential impacts of the estimated take on the affected mysticete
stocks.
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North Atlantic Right Whale (Western Stock)--
NARW are listed as endangered under the ESA and as both a depleted
and strategic stock under the MMPA. The current stock abundance
estimate is 372 animals. As described in the Unusual Mortality Events
section, a UME has been designated for NARW. NARW are migratory, though
they have been detected across their range year-round. Detections in
the mid-Atlantic are occurring more frequently (Engelhaupt et al.
2023), and the Density Technical Report predicts a NARW density in the
Mid-Atlantic Bight that is almost an order of magnitude higher from
2010 to 2019 compared to 2003 to 2009, which is consistent with visual
and acoustic surveys showing an increase in the use of the region
(Davis et al., 2020; O'Brien et al., 2022).
As described in the Description of Marine Mammals and Their Habitat
in the Area of the Specified Activities section, the AFTT Study Area
overlaps with the NARW migratory corridor BIA, which represents areas
and months within which a substantial portion of a species or
population is known to migrate (LaBrecque et al. 2015). The Study Area
also overlaps three seasonal feeding BIAs in the northeast Atlantic, a
seasonal mating BIA in the central Gulf of Maine, and a seasonal
calving BIA in the southeast Atlantic (LaBrecque et al. 2015), as well
as important feeding habitat in southern New England, primarily along
the western side of Nantucket Shoals (Estabrook et al., 2022; Kraus et
al., 2016; Leiter et al., 2017; O'Brien et al., 2022, Quintano-Rizzo et
al., 2021). Additionally, the AFTT Study Area overlaps ESA-designated
critical habitat for the NARW (Unit 1 and Unit 2) as described in the
Critical Habitat section of this rule.
NARW are threatened due to a low population abundance, compromised
body condition, high mortality rates, and low reproductive rates. They
face several chronic anthropogenic and non-anthropogenic risk factors,
including vessel strike, and entanglement, among others. Recent studies
have reported individuals showing high stress levels (e.g., Corkeron et
al., 2017) and poor health, which has further implications on
reproductive success and calf survival (Christiansen et al., 2020;
Stewart et al., 2021; Stewart et al., 2022; Pirotta et al. 2024). Given
these factors, the status of the NARW population is of heightened
concern and, therefore, additional analysis is warranted.
As shown in table 50, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment are 2
and 414, respectively. Given the current status of the NARW, the loss
of even one individual could significantly impact the population.
However, no mortality is anticipated or authorized, nor is any non-
auditory injury. The total take allowable across all 7 years of the
rule is indicated in table 16.
Regarding the potential takes associated with auditory impairment,
as described in the Auditory Injury from Sonar Acoustic Sources and
Explosives and Non-Auditory Injury from Explosives section of the
proposed rule (90 FR 19858, May 9, 2025), any takes in the form of TTS
are expected to be lower-level, of short duration (from minutes to, at
most, several hours or less than a day), and mostly not in a frequency
band that would be expected to interfere with NARW communication or
other important low-frequency cues. Any associated lost opportunities
or capabilities individuals might experience as a result of TTS would
not be at a level or duration that would be expected to impact
reproductive success or survival. For similar reasons, while auditory
injury impacts last longer, the low anticipated levels of AUD INJ that
could be reasonably expected to result from these activities are
unlikely to have any effect on fitness.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 172 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. NARWs are
large-bodied capital breeders with a slow pace of life, which would
generally be less susceptible to impacts from shorter duration foraging
disruptions.
Further, as described in the Group and Species-Specific Analyses
section above and the Mitigation Measures section, mitigation measures,
several of which are designed specifically to reduce impacts to NARW,
are expected to further reduce the potential severity of impacts
through real-time operational measures that minimize higher level/
longer duration exposures and time/area measures that reduce impacts in
high value habitat. Specifically, this rule includes the following
geographic mitigation areas for NARW: (1) Northeast North Atlantic
Right Whale Mitigation Area; (2) Gulf of Maine Mitigation Area; (3)
Martha's Vineyard North Atlantic Right Whale Mitigation Area; (4)
Jacksonville Operating Area North Atlantic Right Whale Mitigation Area;
(5) Southeast North Atlantic Right Whale Mitigation Area; (6) Dynamic
North Atlantic Right Whale Mitigation Area; (7) MTE Planning Awareness
Mitigation Areas in the northeast and mid-Atlantic; and (8) ship shock
trial mitigation areas. The Northeast North Atlantic Right Whale
Mitigation Area and Southeast North Atlantic Right Whale Mitigation
Area in particular would reduce exposures in times and areas where
impacts would be more likely to affect feeding and energetics (note
that these mitigation areas are not quantitatively accounted for in the
modeling, which means that the mitigation may prevent some of the takes
predicted, though the analysis considers that they could all occur).
Also, because of the required mitigation measures, the estimated takes
would be less likely to occur in areas or at times where impacts would
be likely to affect feeding and energetics or important cow/calf
interactions that could lead to reduced reproductive success or
survival, including those in areas known to be biologically important,
and such impacts are not anticipated. Any impacts predicted in the east
coast migratory corridor are less likely to impact individuals during
feeding or breeding behaviors.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
number of takes by harassment as compared to the stock/species
abundance (see table 50), it is likely that some portion of the
individuals taken are taken repeatedly over a limited number of days,
particularly in the northeast (70 percent of the takes predicted are in
this region) during the winter and spring where and when a combined 58
percent of takes of this stock would occur and animals are likely
feeding. This is when NARW have a higher density at feeding grounds
located near and south of Cape Cod, including areas overlapped by the
Narragansett Bay OPAREA in the Northeast Range Complexes, and in the
migratory corridor through the northeast region. However, given the
variety of activity types that contribute to take across separate
exercises conducted at different times and in different areas, the fact
that many result from transient activities conducted at sea, and fact
that the number of takes as compared to the abundance is just above 100
percent
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(112 percent), it is unlikely that takes would be in high enough
numbers for any one individual or occur clumped across sequential days
in a manner likely to impact foraging success and energetics, or that
other behaviors such that reproduction or survival of any individuals
is likely to be impacted.
Given the magnitude and severity of the impacts discussed above to
NARW (considering annual take maxima and the total across 7 years) and
their habitat, and in consideration of the required mitigation measures
and other information presented, the Action Proponents' activities are
unlikely to result in impacts on the reproduction or survival of any
individuals and, thereby, unlikely to affect annual rates of
recruitment or survival. Further, we have considered the UME for NARW
species described above, and even in consideration of the fact that
some of the affected individuals may have compromised health, given the
anticipated impacts of the activity, the take authorized by this rule
is not expected to exacerbate the effects of the UME or otherwise
impact the population. For these reasons, we have determined that the
take by harassment anticipated and authorized will have a negligible
impact on the Western stock of NARW.
Blue Whale (Western North Atlantic Stock)--
Blue whales are listed as endangered under the ESA and as both
depleted and strategic under the MMPA. The stock abundance is currently
unknown, though NMFS' SAR reports an Nmin of 402. The
stock's primary range is outside of the AFTT Study Area. There are no
UMEs or other factors that cause particular concern for this stock, and
there are no known BIAs for blue whales in the AFTT Study Area. They
are frequently located in continental shelf waters near eastern Canada
but have also been sighted off the coast of Florida and along the mid-
Atlantic ridge (likely the southern portion of their feeding range).
Blue whales face several chronic anthropogenic and non-anthropogenic
risk factors, including vessel strike, and entanglement, among others.
As shown in table 50, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment are 1
and 71, respectively. No mortality is anticipated or authorized, nor is
any non-auditory injury. The total take allowable across all 7 years of
the rule is indicated in table 16.
Regarding the potential takes associated with auditory impairment,
as described in the Auditory Injury from Sonar Acoustic Sources and
Explosives and Non-Auditory Injury from Explosives section of the
proposed rule (90 FR 19858, May 9, 2025), any takes in the form of TTS
are expected to be lower-level, of short duration, and mostly not in a
frequency band that would be expected to interfere with blue whale
communication or other important low-frequency cues. Any associated
lost opportunities or capabilities individuals might experience as a
result of TTS would not be at a level or duration that would be
expected to impact reproductive success or survival. For similar
reasons, while auditory injury impacts last longer, the low anticipated
levels of AUD INJ that could be reasonably expected to result from
these activities are unlikely to have any effect on fitness.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 172 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Blue whales are
large-bodied capital breeders with a slow pace of life and are
therefore generally less susceptible to impacts from shorter duration
foraging disruptions. Further, as described in the Group and Species-
Specific Analyses section above and the Mitigation Measures section,
mitigation measures are expected to further reduce the potential
severity of impacts through real-time operational measures that
minimize higher level/longer duration exposures and time/area measures
that reduce impacts in high value habitat.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
lower number of takes by harassment as compared to the stock/species
abundance (see table 50), their migratory movement pattern, and the
absence of take concentrated in areas in which animals are known to
congregate, it is unlikely that any individual blue whales would be
taken on more than a limited number of days within a year and,
therefore, the anticipated behavioral disturbance is not expected to
affect reproduction or survival.
Given the magnitude and severity of the impacts discussed above to
blue whales (considering annual take maxima and the total across 7
years) and their habitat, and in consideration of the required
mitigation measures and other information presented, the Action
Proponents' activities are not expected to result in impacts on the
reproduction or survival of any individuals, much less affect annual
rates of recruitment or survival. For these reasons, we have determined
that the take by harassment anticipated and authorized will have a
negligible impact on the Western North Atlantic stock of blue whales.
Bryde's Whale (Primary)--
This population of Bryde's whales spans the mid- and southern
Atlantic. They have not been designated as a stock under the MMPA, are
not ESA-listed, and there is no current reported population trend.
There are no UMEs or other factors that cause particular concern for
this stock and no known BIAs for Bryde's whale in the AFTT Study Area.
Most Bryde's whales congregate in tropical waters south of the AFTT
Study Area, and only occasionally travel as far north as Virginia.
Bryde's whales generally face several chronic anthropogenic and non-
anthropogenic risk factors, including vessel strike, and entanglement,
among others.
As shown in table 50, the maximum annual allowable instances of
take under this rule by Level B harassment is 11. No mortality is
anticipated or authorized, nor is any auditory or non-auditory injury
(Level A harassment). The total take allowable across all 7 years of
the rule is indicated in table 16.
Regarding the potential takes associated with TTS, as described in
the Temporary Threshold Shift section of the proposed rule (90 FR
19858, May 9, 2025), any takes in the form of TTS are expected to be
lower-level, of short duration, and mostly not in a frequency band that
would be expected to interfere with Bryde's whale communication or
other important low-frequency cues. Any associated lost opportunities
or capabilities individuals might experience as a result of TTS would
not be at a level or duration that would be expected to impact
reproductive success or survival.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 172 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a
[[Page 50661]]
few minutes to several hours. Bryde's whales are large-bodied income
breeders with a slow pace of life and may be susceptible to energetic
costs from foraging disruption, especially during lactation.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
low number of takes by harassment (see table 50), their migratory
movement pattern, and the absence of take concentrated in areas in
which animals are known to congregate, it is unlikely that any
individual Bryde's whales would be taken on more than a limited number
of days within a year and, therefore, the anticipated behavioral
disturbance is not expected to affect reproduction or survival.
Given the magnitude and severity of the impacts discussed above to
this population of Bryde's whales (considering annual take maxima and
the total across 7 years) and their habitat, and in consideration of
the required mitigation measures and other information presented, the
Action Proponents' activities are not expected to result in impacts on
the reproduction or survival of any individuals, much less affect
annual rates of recruitment or survival. For these reasons, we have
determined that the take by harassment anticipated and authorized will
have a negligible impact on Bryde's whales.
Fin Whale (Western North Atlantic Stock)--
Fin whales are listed as endangered under the ESA throughout the
species' range and as both depleted and strategic under the MMPA. The
Western North Atlantic stock abundance is 6,802 animals. There are no
UMEs or other factors that cause particular concern for this stock. As
described in the Description of Marine Mammals and Their Habitat in the
Area of the Specified Activities section, the AFTT Study Area overlaps
three fin whale feeding BIAs: (1) June to October in the northern Gulf
of Maine; (2) year-round in the southern Gulf of Maine; and (3) March
to October east of Montauk Point (LaBrecque et al. 2015). More recent
data supports that these areas remain biologically important (King et
al., 2021; Lomac-MacNair et al., 2022). There is no ESA-designated
critical habitat for fin whales in the AFTT Study Area. The Western
North Atlantic stock of fin whales may be present year-round in the
Atlantic with higher densities near the shelf break in the northeast
and mid-Atlantic. Densities near feeding areas on the shelf in the
northeast are higher in the summer. Fin whales face several chronic
anthropogenic and non-anthropogenic risk factors, including vessel
strike, and entanglement, among others.
As shown in table 50, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment are
21 and 2,616, respectively. As indicated, the rule also allows for up
to 2 takes by serious injury or mortality over the course of the 7-year
rule, the impacts of which are discussed above in the Serious Injury
and Mortality section. No non-auditory injury is anticipated or
authorized. The total take allowable across all 7 years of the rule is
indicated in table 16.
Regarding the potential takes associated with auditory impairment,
as described in the Auditory Injury from Sonar Acoustic Sources and
Explosives and Non-Auditory Injury from Explosives section of the
proposed rule (90 FR 19858, May 9, 2025), any takes in the form of TTS
are expected to be lower-level, of short duration (even the longest
recovering in less than a day), and mostly not in a frequency band that
would be expected to interfere with fin whale communication or other
important low-frequency cues. Any associated lost opportunities or
capabilities individuals might experience as a result of TTS would not
be at a level or duration that would be expected to impact reproductive
success or survival. For similar reasons, while auditory injury impacts
last longer, the low anticipated levels of AUD INJ that could be
reasonably expected to result from these activities are unlikely to
have any effect on fitness.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 172 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Of the takes by
Level B harassment, 5 would occur east of Montauk Point between March
and October, and 52 would occur in the southern Gulf of Maine, both
areas known to be biologically important for fin whale foraging. None
of the takes by Level A harassment would occur in areas known to be
biologically important. However, given that fin whales are large-bodied
capital breeders with a slow pace of life and are therefore generally
less susceptible to impacts from shorter duration foraging disruptions,
as well as the limited number of takes anticipated to occur in the BIA,
we do not anticipate that takes in this BIA would occur to any
individual fin whale on more than a limited number of days within a
year, as described further below. Further, as described in the Group
and Species-Specific Analyses section above and the Mitigation Measures
section, mitigation measures are expected to further reduce the
potential severity of impacts through real-time operational measures
that minimize higher level/longer duration exposures and time/area
measures that reduce impacts in high value habitat.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
number of takes by harassment as compared to the stock/species
abundance (see table 50), it is likely that some portion of the
individuals taken are taken repeatedly over a limited number of days.
However, given the variety of activity types that contribute to take
across separate exercises conducted at different times and in different
areas, and the fact that many result from transient activities
conducted at sea, it is unlikely that repeated takes would occur either
in numbers or clumped across sequential days in a manner likely to
impact foraging success and energetics or other behaviors such that
reproduction or survival of any individuals are likely to be impacted.
Further, this stock is migratory, and the takes are not concentrated
within a specific season.
As analyzed and described in the Mortality section above, given the
status of the stock and in consideration of other ongoing human-caused
mortality, the M/SI authorized by this rule for the Western North
Atlantic stock of fin whales (2 over the course of the 7-year rule, or
0.29 annually) would not, alone, be expected to adversely affect the
stock through rates of recruitment or survival. Given the magnitude and
severity of the take by harassment discussed above and any anticipated
habitat impacts, and in consideration of the required mitigation
measures and other information presented, the take by harassment
authorized is unlikely to result in impacts on the reproduction or
survival of any individuals and, thereby, unlikely to affect annual
rates of recruitment or survival either alone or in combination with
the M/SI authorized by this rule. For these
[[Page 50662]]
reasons, we have determined that the take anticipated and authorized
will have a negligible impact on the Western North Atlantic stock of
fin whales.
Humpback Whale (Gulf of Maine Stock)--
The West Indies distinct population segment (DPS) of humpback
whales is not listed as threatened or endangered under the ESA, and the
Gulf of Maine stock, which includes individuals from the West Indies
DPS, is not considered depleted or strategic under the MMPA. The stock
abundance is 1,396 animals. As described in the Description of Marine
Mammals and Their Habitat in the Area of the Specified Activities
section, humpback whales along the Atlantic Coast have been
experiencing an active UME as elevated humpback whale mortalities have
occurred along the Atlantic coast from Maine through Florida since
January 2016. Of the cases examined, approximately 40 percent had
evidence of human interaction (vessel strike or entanglement). As also
described in the Description of Marine Mammals and Their Habitat in the
Area of the Specified Activities section, the AFTT Study Area overlaps
a humpback whale feeding BIA (LaBrecque et al. 2015). This BIA is
further supported by more recent information that suggests that the
Gulf of Maine, Mid-Atlantic Shelf, New York Bight, and south New
England are all important for humpback whale feeding (Brown et al.,
2019; Hayes et al., 2019; Aschettino et al., 2020; Davis et al., 2020;
Zeh et al., 2020; King et al., 2021; Pershing et al., 2021; Stepanuk et
al., 2021; Zoidis et al., 2021; Lomac-MacNair et al., 2022; Smith et
al., 2022). There is no ESA-designated critical habitat for the Gulf of
Maine stock of humpback whales given that the associated DPS is not
ESA-listed. The Gulf of Maine stock of humpback whales have
particularly strong site fidelity in the Gulf of Maine feeding grounds
March to December and in the Caribbean calving grounds from December to
May. Humpback whales, however, may occur in the AFTT Study Area,
particularly in the mid-Atlantic and northeast, year-round. They occur
near the Chesapeake Bay mouth except in the summer. Humpback whales
face several chronic anthropogenic and non-anthropogenic risk factors,
including vessel strike, and entanglement, among others.
As shown in table 50, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment are
12 and 844, respectively. As indicated, the rule also allows for up to
four takes by serious injury or mortality over the course of the 7-year
rule, the impacts of which are discussed above in the Serious Injury
and Mortality section. No non-auditory injury is anticipated or
authorized. The total take allowable across all 7 years of the rule is
indicated in table 16.
Regarding the potential takes associated with auditory impairment,
as described in the Auditory Injury from Sonar Acoustic Sources and
Explosives and Non-Auditory Injury from Explosives section of the
proposed rule (90 FR 19858, May 9, 2025), any takes in the form of TTS
are expected to be lower-level, of short duration (even the longest
recovering in several hours or less than a day), and mostly not in a
frequency band that would be expected to interfere with humpback whale
communication or other important low-frequency cues. Any associated
lost opportunities or capabilities individuals might experience as a
result of TTS would not be at a level or duration that would be
expected to impact reproductive success or survival. For similar
reasons, while auditory injury impacts last longer, the low anticipated
levels of AUD INJ that could be reasonably expected to result from
these activities are unlikely to have any effect on fitness.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 172 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Humpback whales
are large-bodied capital breeders with a slow pace of life and are
therefore generally less susceptible to impacts from shorter duration
foraging disruptions. Further, as described in the Group and Species-
Specific Analyses section above and the Mitigation Measures section,
mitigation measures are expected to further reduce the potential
severity of impacts through real-time operational measures that
minimize higher level/longer duration exposures and time/area measures
that reduce impacts in high value habitat.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
number of takes by harassment as compared to the stock/species
abundance (see table 50) and the fact that a portion of the takes occur
in BIAs, it is likely that some portion of the individuals taken are
taken repeatedly over a limited number of days. However, given the
migratory nature of the stock, the variety of activity types that
contribute to take across separate exercises conducted at different
times and in different areas (i.e., not concentrated within a specific
region and season), and the fact that many result from transient
activities conducted at sea, it is unlikely that repeated takes would
occur either in numbers or clumped across sequential days in a manner
likely to impact foraging success and energetics or other behaviors
such that reproduction or survival of any individuals is are likely to
be impacted. Further, as noted above, humpback whales are large-bodied
capital breeders with a slow pace of life and are therefore generally
less susceptible to impacts from shorter duration foraging disruptions.
As analyzed and described in the Serious Injury and Mortality section
above, given the status of the stock and in consideration of other
ongoing human-caused mortality, the M/SI authorized by this rule for
Gulf of Maine humpback whales (four over the course of the 7-year rule,
or 0.57 annually) would not, alone, be expected to adversely affect the
stock through rates of recruitment or survival. Given the magnitude and
severity of the take by harassment discussed above and any anticipated
habitat impacts, and in consideration of the required mitigation
measures and other information presented, the take by harassment
authorized by this rule is unlikely to result in impacts on the
reproduction or survival of any individuals and, thereby, unlikely to
affect annual rates of recruitment or survival either alone or in
combination with the M/SI authorized by this rule. Last, we have both
considered the effects of the UME on this stock in our analysis and
findings regarding the impact of the activity on the stock and also
determined that we do not expect the authorized take to exacerbate the
effects of the UME or otherwise impact the population. For these
reasons, we have determined that the anticipated and authorized take
will have a negligible impact on the Gulf of Maine stock of humpback
whales.
Minke Whale (Canadian East Coast Stock)--
Minke whales are not listed as threatened or endangered under the
ESA and are not considered depleted or strategic under the MMPA. The
stock abundance is 21,968 animals (Hayes et al., 2024). The stock's
range extends beyond the AFTT Study Area. There is
[[Page 50663]]
an ongoing UME for minke whales along the Atlantic Coast from Maine
through South Carolina, with the highest number of deaths in
Massachusetts, Maine, and New York. Preliminary findings in several of
the whales have shown evidence of human interactions or infectious
diseases. However, we note that the stock abundance is greater than
21,000 and the take authorized is not expected to exacerbate the UME in
any way. As described in the Description of Marine Mammals and Their
Habitat in the Area of the Specified Activities section, the AFTT Study
Area overlaps two minke whale feeding BIAs (LaBrecque et al., 2015;
CETAP, 1982; Murphy, 1995). There is no ESA-designated critical habitat
for minke whales, as the species is not ESA-listed. Minke whales face
several chronic anthropogenic and non-anthropogenic risk factors,
including vessel strike and entanglement, among others.
As shown in table 50, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment are
56 and 4,643, respectively. As indicated, the rule also allows for up
to two takes by serious injury or mortality over the course of the 7-
year rule, the impacts of which are discussed above in the Serious
Injury and Mortality section. The total take allowable across all 7
years of the rule is indicated in table 16.
Regarding the potential takes associated with auditory impairment,
as described in the Auditory Injury from Sonar Acoustic Sources and
Explosives and Non-Auditory Injury from Explosives section of the
proposed rule (90 FR 19858, May 9, 2025), any takes in the form of TTS
are expected to be lower-level, of short duration, and mostly not in a
frequency band that would be expected to interfere with minke whale
communication or other important low-frequency cues. Any associated
lost opportunities or capabilities individuals might experience as a
result of TTS would not be at a level or duration that would be
expected to impact reproductive success or survival. For similar
reasons, while auditory injury impacts last longer, the low anticipated
levels of AUD INJ that could be reasonably expected to result from
these activities are unlikely to have any effect on fitness.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 172 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Minke whales
are medium-to-large-bodied capital breeders with a slow pace of life
and are therefore generally less susceptible to impacts from shorter
duration foraging disruptions. Further, as described in the Group and
Species-Specific Analyses section above and the Mitigation Measures
section, mitigation measures are expected to further reduce the
potential severity of impacts through real-time operational measures
that minimize higher level/longer duration exposures and time/area
measures that reduce impacts in high value habitat.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
lower number of takes by harassment as compared to the stock/species
abundance (see table 50), their migratory movement pattern, and the
absence of take concentrated in areas in which animals are known to
congregate, it is unlikely that any individual minke whales would be
taken on more than a limited number of days within a year and,
therefore, the anticipated behavioral disturbance is not expected to
affect reproduction or survival.
As analyzed and described in the Mortality section above, given the
status of the stock and in consideration of other ongoing human-caused
mortality, the M/SI authorized by this rule for Canadian East Coast
minke whales (two over the course of the 7-year rule, or 0.29 annually)
would not, alone, be expected to adversely affect the stock through
rates of recruitment or survival. Given the magnitude and severity of
the take by harassment discussed above and any anticipated habitat
impacts, and in consideration of the required mitigation measures and
other information presented, the take by harassment authorized by this
rule is unlikely to result in impacts on the reproduction or survival
of any individuals and, thereby, unlikely to affect annual rates of
recruitment or survival either alone or in combination with the M/SI
authorized by this rule. Last, we have both considered the effects of
the UME on this stock in our analysis and findings regarding the impact
of the activity on the stock, and, also, determined that we do not
expect the authorized take to exacerbate the effects of the UME or
otherwise impact the population. For these reasons, we have determined
that the take anticipated and authorized will have a negligible impact
on the Canadian East Coast stock of minke whales.
Rice's Whale (Northern Gulf of America Stock)--
Rice's whales are listed as endangered under the ESA and as both
depleted and strategic under the MMPA. The stock abundance is 51
animals (Hayes et al., 2024). The AFTT Study Area overlaps the Rice's
whale small and resident population BIA (LaBrecque et al. 2015, further
supported by more recent information (e.g., Rosel et al. 2021, Garrison
et al. 2024)), as well as proposed ESA-designated critical habitat (88
FR 47453, July 24, 2023), as described in the Description of Marine
Mammals in the Area of Specified Activities section. Rice's whales face
several chronic anthropogenic and non-anthropogenic risk factors,
including vessel strike, energy exploration and development, and a
limited population size and distribution, among others. Although this
stock is not experiencing a UME, given the stock's status, low
abundance and vulnerability, constricted range, and lingering effects
of exposure to oil from the DWH oil spill (which include adverse health
effects on individuals, as well as population effects), additional
analysis is warranted.
Although there is new evidence of Rice's whale occurrence in the
central and western Gulf of America from passive acoustic detections
(Soldevilla et al., 2022; 2024), the highest densities of Rice's whales
remain confined to the northeastern Gulf of America core habitat, where
their occurrence would overlap activities conducted in the offshore
portions of the Naval Surface Warfare Center, Panama City Division
Testing Area. The number of individuals that occur in the central and
western Gulf of America and nature of their use of this area is poorly
understood. Soldevilla et al. (2022) suggest that more than one
individual was present on at least one occasion, as overlapping calls
of different call subtypes were recorded in that instance, but also
state that call detection rates suggest that either multiple
individuals are typically calling or that individual whales are
producing calls at higher rates in the central/western Gulf of America.
Soldevilla et al. (2024) provide further evidence that Rice's whale
habitat encompasses all 100-400 m (328-1,312 ft) depth waters
encircling the entire Gulf of America (including Mexican waters), but
they also note that further research is needed to understand the
density of whales in these areas, seasonal changes in whale density,
and other aspects of habitat usage.
[[Page 50664]]
As shown in table 50, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment are 3
and 303, respectively. No mortality is anticipated or authorized, nor
is any non-auditory injury. The total take allowable across all 7 years
of the rule is indicated in table 16. Most impacts to Rice's whale are
due to UUV testing, which may use sonars at a variety of frequencies
for multiple hours most days of the year on the testing range. 44
percent of takes of this stock would occur during the winter when
Rice's whale densities are predicted to be highest in the northeastern
Gulf of America.
Regarding the potential takes associated with auditory impairment,
as described in the Auditory Injury from Sonar Acoustic Sources and
Explosives and Non-Auditory Injury from Explosives section of the
proposed rule (90 FR 19858, May 9, 2025), any takes in the form of TTS
are expected to be lower-level, of short duration (from minutes to, at
most, several hours or less than a day), and mostly not in a frequency
band that would be expected to interfere with Rice's whale
communication or other important low-frequency cues. Any associated
lost opportunities or capabilities individuals might experience as a
result of TTS would not be at a level or duration that would be
expected to impact reproductive success or survival. For similar
reasons, while auditory injury impacts last longer, the low anticipated
levels of AUD INJ that could be reasonably expected to result from
these activities are unlikely to have any effect on fitness.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 172 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Rice's whales
are large-bodied income breeders (Constantine et al., 2018) with a slow
pace of life, which may make them susceptible to repeated short-term
foraging losses over time. As described in the Group and Species-
Specific Analyses section above and the Mitigation Measures section,
mitigation measures are expected to further reduce the potential
severity of impacts through real-time operational measures that
minimize higher level/longer duration exposures and time/area measures
that reduce impacts in high value habitat. In particular, this
rulemaking includes a Rice's Whale Mitigation Area that overlaps the
Rice's whale small and resident population area identified by NMFS in
its 2016 status review (Rosel et al., 2016). This area encompasses the
area where Rice's whales are most likely to occur as well as most of
the eastern portion of proposed critical habitat. Within this area, the
Action Proponents must not use more than 200 hours of surface ship
hull-mounted mid-frequency active sonar annually and must not detonate
in-water explosives (including underwater explosives and explosives
deployed against surface targets) except during mine warfare
activities. Additionally, the Ship Shock Trial Mitigation Area would
ensure that the northern Gulf of America ship shock trial box is
situated outside of the Rice's whale core distribution area. These
restrictions would reduce the severity of impacts to Rice's whales by
reducing their exposure to levels of sound from sonar or explosives
that would have the potential to cause injury or mortality, thereby
reducing the likelihood of those effects and further minimizing the
severity of behavioral disturbance.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
number of takes by harassment as compared to the stock/species
abundance (see table 50), it is likely that some portion of the
individuals taken are taken repeatedly over a moderate number of days.
Whereas most large whales exhibit migratory movement patterns, Rice's
whales are a resident species within the Gulf of America, where they
live year-round, so the risk of repeated impacts on individuals is
likely similar within the population as animals move throughout their
range. Further, given the variety of activity types that contribute to
take across separate exercises conducted at different times and in
different areas, and the fact that many result from transient
activities conducted at sea, it is unlikely that takes would occur
either in numbers or clumped across sequential days in a manner likely
to impact foraging success and energetics or other behaviors such that
reproduction or survival are likely to be impacted. While Rice's whale
core habitat is in the northeastern portion of the Gulf of America
which has been identified as biologically important (LaBrecque et al.
2015), and a majority of takes would occur in that area, additional
important Rice's whale habitat occurs between the 100-400 m (328-1,312
ft) isobath in the Gulf of America (Soldevilla et al., 2024; 88 FR
47453, July 24, 2023).
Given the magnitude and severity of the impacts discussed above on
Rice's whale (considering annual take maxima and the total across 7
years) and their habitat, and in consideration of the required
mitigation measures and other information presented, the Action
Proponents' activities are unlikely to result in impacts on the
reproduction or survival of any individuals and, thereby, unlikely to
affect annual rates of recruitment or survival. Last, we are aware that
Rice's whales have experienced lower rates of reproduction and survival
since the DWH oil spill; however, those effects are reflected in the
SARs and other data considered in these analyses and do not change our
findings. For these reasons, we have determined that the take by
harassment anticipated and authorized will have a negligible impact on
Rice's whale.
Sei Whale (Nova Scotia Stock)--
Sei whales are listed as endangered under the ESA throughout its
range and are considered depleted and strategic under the MMPA. The
Nova Scotia stock abundance is 6,292 animals. There are no UMEs or
other factors that cause particular concern for this stock. As
described in the Description of Marine Mammals and Their Habitat in the
Area of the Specified Activities section, the AFTT Study Area overlaps
a sei whale feeding BIA. There is no ESA-designated critical habitat
for sei whales in the AFTT Study Area. The highest sei whale abundance
in U.S. waters occurs during spring, with sightings concentrated along
the eastern margin of Georges Bank, into the Northeast Channel area,
south of Nantucket, and along the southwestern edge of Georges Bank
(CETAP 1982; Hayes et al. 2024; Kraus et al. 2016; Roberts et al. 2016;
Palka et al. 2017; Cholewiak et al. 2018). Sei whales face several
chronic anthropogenic and non-anthropogenic risk factors, including
vessel strike, and entanglement, among others.
As shown in table 50, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment are 7
and 747, respectively. As indicated, the rule also allows for up to two
takes by serious injury or mortality over the course of the 7-year
rule, the impacts of which are discussed above in the Serious Injury
and Mortality section. The total take allowable across all 7 years of
the rule is indicated in table 16.
Regarding the potential takes associated with auditory impairment,
as
[[Page 50665]]
described in the Auditory Injury from Sonar Acoustic Sources and
Explosives and Non-Auditory Injury from Explosives section of the
proposed rule (90 FR 19858, May 9, 2025), any takes in the form of TTS
are expected to be lower-level, of short duration, and mostly not in a
frequency band that would be expected to interfere with sei whale
communication or other important low-frequency cues. Any associated
lost opportunities or capabilities individuals might experience as a
result of TTS would not be at a level or duration that would be
expected to impact reproductive success or survival. For similar
reasons, while auditory injury impacts last longer, the low anticipated
levels of AUD INJ that could be reasonably expected to result from
these activities are unlikely to have any effect on fitness.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 172 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Sei whales are
large-bodied capital breeders with a slow pace of life and are
therefore generally less susceptible to impacts from shorter duration
foraging disruptions. Further, as described in the Group and Species-
Specific Analyses section above and the Mitigation Measures section,
mitigation measures are expected to further reduce the potential
severity of impacts through real-time operational measures that
minimize higher level/longer duration exposures and time/area measures
that reduce impacts in high value habitat.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
lower number of takes by harassment as compared to the stock/species
abundance (see table 50) and their migratory movement pattern, it is
unlikely that any individual sei whales would be taken on more than a
limited number of days within a year and, therefore, the anticipated
behavioral disturbance is not expected to affect reproduction or
survival.
As analyzed and described in the Mortality section above, given the
status of the stock and in consideration of other ongoing human-caused
mortality, the M/SI authorized by this rule for the Nova Scotia stock
of sei whales (two over the course of the 7-year rule, or 0.29
annually) would not, alone, be expected to adversely affect the stock
through rates of recruitment or survival. Given the magnitude and
severity of the take by harassment discussed above and any anticipated
habitat impacts, and in consideration of the required mitigation
measures and other information presented, the take by harassment
authorized by this rule is unlikely to result in impacts on the
reproduction or survival of any individuals and, thereby, unlikely to
affect annual rates of recruitment or survival either alone or in
combination with the M/SI authorized by this rule. For these reasons,
we have determined that the take anticipated and authorized will have a
negligible impact on the Nova Scotia stock of sei 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 stocks will incur, the applicable mitigation for each stock,
and the status and life history of the stocks to support the negligible
impact determinations for each stock. We have already described above
why we believe the incremental addition of the limited number of low-
level auditory injury takes will not have any meaningful effect towards
inhibiting reproduction or survival. We have also described above in
this section the unlikelihood of any masking or habitat impacts having
effects that would impact the reproduction or survival of any of the
individual marine mammals affected by the Action Proponents'
activities. Some odontocete stocks have predicted non-auditory injury
from explosives, discussed further below. Regarding the severity of
individual takes by Level B harassment by behavioral disturbance for
odontocetes, the majority of these responses are anticipated to occur
at received levels below 178 dB for most odontocete species and below
154 dB for sensitive species (i.e., beaked whales and harbor porpoises,
for which a lower behavioral disturbance threshold is applied), and
last from a few minutes to a few hours, at most, with associated
responses most likely in the form of moving away from the source,
foraging interruptions, vocalization changes, or disruption of other
social behaviors, lasting from a few minutes to several hours. Much of
the discussion below focuses on the behavioral effects and the
mitigation measures that reduce the probability or severity of effects
in BIAs or other habitat. Because there are multiple stock-specific
factors in relation to the status of the species, as well as mortality
take for several stocks, at the end of the section we break out stock-
or group-specific findings.
Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales--
In table 52 (sperm whales, dwarf sperm whales, and pygmy sperm
whales), table 54 (beaked whales), table 56 (dolphins and small
whales), table 58 (porpoises), and table 60 (pinnipeds) below, we
indicate the total annual mortality, Level A harassment, and Level B
harassment, and the maximum annual harassment as a percentage of stock
abundance.
In table 53 (sperm whales, dwarf sperm whales, and pygmy sperm
whales), table 55 (beaked whales), table 57 (dolphins and small
whales), table 59 (porpoises), and table 61 (pinnipeds), below, we
indicate the status, life history traits, important habitats, and
threats that inform our analysis of the potential impacts of the
estimated take on the affected odontocete stocks.
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Sperm Whale (North Atlantic Stock), Dwarf Sperm Whale (Western North
Atlantic and Northern Gulf of America Stocks), Pygmy Sperm Whale
(Western North Atlantic and Northern Gulf of America Stocks)
Sperm whales are listed as endangered under the ESA and the North
Atlantic stock is considered depleted and strategic under the MMPA.
Neither the dwarf sperm whale nor the pygmy sperm whale is listed under
the ESA, and none of the stocks is considered depleted or strategic.
The stock abundances range from 510 (combined estimate for the Northern
Gulf of America stocks of dwarf and pygmy sperm whales from Navy's
NMSDD) to 5,895 for the North Atlantic stock of sperm whale. There are
no UMEs or other factors that cause particular concern for the stocks
in the Atlantic Ocean, and there are no known BIAs for these stocks in
the AFTT Study Area. These stocks face several chronic anthropogenic
and non-anthropogenic risk factors, including entanglement, among
others.
As shown in table 52, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment range
from 7 (North Atlantic stock of sperm whale) to 180 (Western North
Atlantic stock of dwarf sperm whale) and 175 (Northern Gulf of America
stock of pygmy sperm whale) to 12,590 (North Atlantic stock of sperm
whale), respectively. As indicated, the rule also allows for up to two
takes by serious injury or mortality of North Atlantic sperm whales
over the course of the 7-year rule, the impacts of which are discussed
above in the Serious Injury and Mortality section. The total take
allowable for each stock across all 7 years of the rule is indicated in
table 16.
Regarding the potential takes associated with auditory impairment,
as described in the Auditory Injury from Sonar Acoustic Sources and
Explosives and Non-Auditory Injury from Explosives section of the
proposed rule (90 FR 19858, May 9, 2025), any takes in the form of TTS
are expected to be lower-level, of short duration (even the longest
recovering in several hours or less than a day), and mostly not in a
frequency band that would be expected to interfere with odontocete
echolocation, overlap more than a relatively narrow portion of the
vocalization range of any single species or stock, or preclude
detection or interpretation of important low-frequency cues. Any
associated lost opportunities or capabilities individuals might
experience as a result of TTS would not be at a level or duration that
would be expected to impact reproductive success or survival. For
similar reasons, while auditory injury impacts last longer, the low
anticipated levels of AUD INJ that could be reasonably expected to
result from these activities are unlikely to have any effect on
fitness. The rule also allows for one take of North Atlantic sperm
whale by non-auditory injury (table 17). As described above, given the
limited number of potential exposures and the anticipated effectiveness
of the mitigation measures in minimizing the pressure levels to which
any individuals are exposed, these injuries are unlikely to impact
reproduction or survival.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 178 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Pygmy and dwarf
sperm whales are small-medium bodied income breeders with a fast pace
of life. They are generally more sensitive to missed foraging
opportunities, especially during lactation, but would be quick to
recover given their fast pace of life. Sperm whales are large-bodied
income breeders with a slow pace of life and are likely more resilient
to missed foraging opportunities due to acoustic disturbance than
smaller odontocetes. However, they may be more susceptible to impacts
due to lost foraging opportunities during reproduction, especially if
they occur during lactation (Farmer et al., 2018). Further, as
described in the Group and Species-Specific Analyses section above and
the Mitigation Measures section, mitigation measures are expected to
further reduce the potential severity of impacts through real-time
operational measures that minimize higher level/longer duration
exposures and time/area measures that reduce impacts in high value
habitat.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
number of takes by harassment as compared to the stock/species
abundance (see table 52) and the fact that the majority of takes of the
Northern Gulf of America stock of pygmy and dwarf sperm whale occur in
the Gulf of America (95 and 96 percent, respectively), and the majority
of takes of the North Atlantic stock of sperm whale and Western North
Atlantic stock of pygmy and dwarf sperm whale occur in the mid-Atlantic
(80, 72, and 73 percent, respectively) it is likely that some portion
of the individuals taken are taken repeatedly over a limited number of
days. However, given the variety of activity types that contribute to
take across separate exercises conducted at different times and in
different areas, and the fact that many result from transient
activities conducted at sea, it is unlikely that repeated takes would
occur either in numbers or clumped across sequential days in a manner
likely to impact foraging success and energetics or other behaviors
such that reproduction or survival are likely to be impacted. Further,
sperm whales are nomadic, and there are no known foraging areas or
other areas within which animals from any of these stocks are known to
congregate.
As analyzed and described in the Serious Injury and Mortality
section above, given the status of the stock and in consideration of
other ongoing human-caused mortality, the M/SI authorized by this rule
for the North Atlantic stock of sperm whales (2 over the course of the
7-year rule, or 0.29 annually) would not, alone, be expected to
adversely affect the stock through rates of recruitment or survival.
Given the magnitude and severity of the take by harassment for each
stock discussed above and any anticipated habitat impacts, and in
consideration of the required mitigation measures and other information
presented, the authorized take by harassment is unlikely to result in
impacts on the reproduction or survival of any individuals and,
thereby, unlikely to affect annual rates of recruitment or survival of
any of these stocks either alone or, for the North Atlantic stock of
sperm whale, in combination with the M/SI authorized by this rule.
Last, we are aware that some Northern Gulf of America stocks have
experienced lower rates of reproduction and survival since the DWH oil
spill; however, those effects are reflected in the SARs and other data
considered in these analyses and do not change our findings. For these
reasons, we have determined that the authorized take by harassment will
have a negligible impact on the North Atlantic stock of sperm whale,
Northern Gulf of America stocks of dwarf and pygmy sperm whales, and
Western North Atlantic stocks of dwarf and pygmy sperm whales.
[[Page 50670]]
Sperm Whale (Northern Gulf of America Stock)
Sperm whales are listed as endangered under the ESA and the
Northern Gulf of America stock is considered depleted and strategic
under the MMPA. The Navy's NMSDD estimates the stock abundance as 1,614
animals. Sperm whales aggregate at the mouth of the Mississippi River
and along the continental slope in or near cyclonic cold-core eddies
(i.e., counterclockwise water movements in the northern hemisphere with
a cold center) or anticyclone eddies (i.e., clockwise water movements
in the northern hemisphere) (Davis et al., 2007). Habitat models for
sperm whale occurrence indicate a high probability of suitable habitat
along the shelf break off the Mississippi delta, Desoto Canyon, and
western Florida (Best et al., 2012; Weller et al., 2000), and this area
may be important for feeding and reproduction (Baumgartner et al.,
2001; Jochens et al., 2008; NMFS, 2010), although the seasonality of
breeding in Northern Gulf of America stock of sperm whales is not known
(Jochens et al., 2008). This stock faces several chronic anthropogenic
and non-anthropogenic risk factors, including vessel strike,
entanglement, and oil spills, among others.
As shown in table 52, the maximum annual allowable instances of
take under this rule by Level B harassment is 275. As indicated, the
rule also allows for up to one take by serious injury or mortality over
the course of the 7-year rule, the impacts of which are discussed above
in the Serious Injury and Mortality section. No Level A harassment
(auditory or non-auditory injury) is authorized. The total take
allowable across all 7 years of the rule is indicated in table 16.
Regarding the potential takes associated with TTS, as described in
the Temporary Threshold Shift section of the proposed rule (90 FR
19858, May 9, 2025), any takes in the form of TTS are expected to be
lower-level, of short duration (even the longest recovering in several
hours or less than a day), and mostly not in a frequency band that
would be expected to interfere with sperm whale communication or other
important low-frequency cues. Any associated lost opportunities or
capabilities individuals might experience as a result of TTS would not
be at a level or duration that would be expected to impact reproductive
success or survival.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 178 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Sperm whales
are large-bodied income breeders with a slow pace of life and are
likely more resilient to missed foraging opportunities due to acoustic
disturbance than smaller odontocetes. However, they may be more
susceptible to impacts due to lost foraging opportunities during
reproduction, especially if they occur during lactation (Farmer et al.,
2018).
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
lower number of takes by harassment as compared to the stock/species
abundance (see table 52), their migratory movement pattern, and the
absence of take concentrated in areas in which animals are known to
congregate, it is unlikely that any individual sperm whales would be
taken on more than a limited number of days within a year and,
therefore, the anticipated behavioral disturbance is not expected to
affect reproduction or survival.
As analyzed and described in the Serious Injury and Mortality
section above, given the status of the stock and in consideration of
other ongoing human-caused mortality, the M/SI authorized by this rule
for the Northern Gulf of America stock of sperm whales (one over the
course of the 7-year rule, or 0.14 annually) would not, alone, be
expected to adversely affect the stock through rates of recruitment or
survival. Given the magnitude and severity of the take by harassment
discussed above and any anticipated habitat impacts, and in
consideration of the required mitigation measures and other information
presented, the authorized take by harassment is unlikely to result in
impacts on the reproduction or survival of any individuals and,
therefore, unlikely to affect annual rates of recruitment or survival
either alone or in combination with the M/SI authorized by this rule.
Last, we are aware that some Northern Gulf of America stocks have
experienced lower rates of reproduction and survival since the DWH oil
spill; however, those effects are reflected in the SARs and other data
considered in these analyses and do not change our findings. For these
reasons, we have determined that the take anticipated and authorized
will have a negligible impact on the Northern Gulf of America stock of
sperm whales.
Beaked Whales--
This section builds on the broader odontocete discussion above
(i.e., that information applies to beaked whales as well), and brings
together the discussion of the different types and amounts of take that
different beaked whale species and stocks will likely incur, any
additional applicable mitigation, and the status of the species and
stocks to support the negligible impact determinations for each species
or stock.
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Beaked Whales (Western North Atlantic Stocks)
These stocks are not listed as endangered or threatened under the
ESA, and they are not considered depleted or strategic under the MMPA.
The stock abundance estimates generally range from 1,279 (Sowerby's
beaked whale, NMSDD) to 8,595 (Gervais' beaked whale). The SAR states
that the abundance of Western North Atlantic northern bottlenose whale
is unknown, and the NMSDD estimates the stock abundance as 82 animals,
but reports that the estimate is from within the EEZ and is lower than
the overall population abundance given that the range of the stock
exceeds the EEZ boundary. See the Density Technical Report for
additional information. There are no UMEs or other factors that cause
particular concern for this stock, and there are no known BIAs for
beaked whales in the AFTT Study Area, though of note, these stocks
generally occur in higher densities year-round in deep waters over the
Atlantic continental shelf margins. The Western North Atlantic stocks
of goose-beaked whales and Blainville's beaked whales generally
congregate over continental shelf margins from Canada to North
Carolina, with goose-beaked whales reported as far south as the
Caribbean and Blainville's beaked whales as far south as the Bahamas.
The Western North Atlantic stock of Gervais' beaked whales generally
congregates over continental shelf margins from New York to North
Carolina. The Western North Atlantic stock of Sowerby's beaked whales
is the most northerly distributed stock of deep-diving mesoplodonts,
and they generally congregate over continental shelf margins from
Labrador to Massachusetts. The Western North Atlantic stock of True's
beaked whales generally congregate over continental shelf margins from
Nova Scotia to Cape Hatteras, with northern occurrence likely relating
to the Gulf Stream. The Western North Atlantic stock of northern
bottlenose whales is uncommon in U.S. waters and generally congregates
in areas of high relief, including shelf breaks and submarine canyons
from the Davis Strait to New England, although strandings have occurred
as far south as North Carolina. Western North Atlantic beaked whales
face several chronic anthropogenic and non-anthropogenic risk factors,
including entanglement, among others.
As shown in table 54, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment range
from 0 to 2 and 1,651 to 112,070, respectively. No mortality is
anticipated or authorized, nor is any non-auditory injury. The total
take allowable across all 7 years of the rule is indicated in table 16.
Regarding the potential takes associated with auditory impairment
(for True's beaked whale, TTS only), as described in the Auditory
Injury from Sonar Acoustic Sources and Explosives and Non-Auditory
Injury from Explosives section of the proposed rule (90 FR 19858, May
9, 2025), any takes in the form of TTS are expected to be lower-level,
of short duration (from minutes to, at most, several hours or less than
a day), and mostly not in a frequency band that would be expected to
interfere with odontocete echolocation, overlap more than a relatively
narrow portion of the vocalization range of any single species or
stock, or preclude detection or interpretation of important low-
frequency cues. Any associated lost opportunities or capabilities
individuals might experience as a result of TTS would not be at a level
or duration that would be expected to impact reproductive success or
survival. For similar reasons, while auditory injury impacts last
longer, the low anticipated levels of AUD INJ that could be reasonably
expected to result from these activities (for all Western North
Atlantic beaked whales except True's beaked whales) are unlikely to
have any effect on fitness.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 154 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Beaked whales
are medium-to-large-bodied odontocetes with a medium pace of life and
likely moderately resilient to missed foraging opportunities due to
acoustic disturbance. They are mixed breeders (i.e., behaviorally
income breeders), and they demonstrate capital breeding strategies
during gestation and lactation (Keen et al., 2021). Therefore, they may
be more vulnerable to prolonged loss of foraging opportunities during
gestation. Further, as described in the Group and Species-Specific
Analyses section above and the Mitigation Measures section, mitigation
measures are expected to further reduce the potential severity of
impacts through real-time operational measures that minimize higher
level/longer duration exposures and time/area measures that reduce
impacts in high value habitat.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
number of takes by harassment as compared to the stock/species
abundance (see table 54), it is likely that some portion of the
individuals taken are taken repeatedly over a small (Western North
Atlantic northern bottlenose whale and Gervais' beaked whale) to
moderate (all other stocks) number of days, with the exception of
Sowerby's beaked whales and goose-beaked whales (discussed below).
However, given the variety of activity types that contribute to take
across separate exercises conducted at different times and in different
areas, and the fact that many result from transient activities
conducted at sea, it is unlikely that takes would occur clumped across
sequential days in a manner likely to impact foraging success and
energetics or other behaviors such that reproduction or survival are
likely to be impacted. Further, while there are several known high-
density areas for goose-beaked whales, around canyons, seamounts, and
Cape Hatteras, which is common for multiple species, there are no known
foraging areas or other areas within which animals are known to
congregate for reproductive or other important behaviors, and nor are
the takes concentrated within a specific region and season.
Regarding the magnitude of repeated takes for the Sowerby's beaked
whales and goose-beaked whales, given the high number of takes by
harassment as compared to the stock abundance, it is more likely that
some number of individuals would experience a comparatively higher
number of repeated takes over a potentially fair number of sequential
days. Due to the higher number of repeated takes, it is more likely
that a portion of the individuals taken by harassment (approximately 50
percent of which would be female) could be repeatedly interrupted
during foraging in a manner and amount such that impacts to the energy
budgets of a limited number of females (from either losing feeding
opportunities or expending considerable energy moving away from sound
sources or finding alternative feeding options) could cause them to
forego reproduction for a year (noting that beaked whale calving
intervals may be about 2 years) (New et al., 2013). Energetic impacts
to males are generally
[[Page 50675]]
meaningless to population rates unless they cause death, and it takes
extreme energy deficits beyond what would ever be likely to result from
these activities to cause the death of an adult marine mammal, male or
female. While the population trend of the Western North Atlantic stock
of Sowerby's beaked whale is not known, it is not considered depleted
or strategic, and there are no known sources of human-caused mortality
indicated in the SARs. Importantly, the increase in a calving interval
by a year would have far less of an impact on a population rate than a
mortality would and, accordingly, a limited number of instances of
foregone reproduction would not be expected to adversely affect this
stock through effects on annual rates of recruitment or survival
(noting also that no mortality is predicted or authorized for this
stock). The population trend of the Western North Atlantic stock of
goose-beaked whales is not known but possibly increasing, and, like the
Sowerby's beaked whale stock, it is not considered depleted or
strategic, and there are no known sources of human-caused mortality
indicated in the SARs. Importantly, the increase in a calving interval
by a year would have far less of an impact on a population rate than a
mortality would and, accordingly, a limited number of instances of
foregone reproduction would not be expected to adversely affect this
stock through effects on annual rates of recruitment or survival
(noting also that no mortality is predicted or authorized for this
stock).
Given the magnitude and severity of the take by harassment
discussed above and any anticipated habitat impacts, and in
consideration of the required mitigation measures and other information
presented, the Action Proponents' activities are unlikely to result in
impacts on the reproduction or survival of any individuals of the
Western North Atlantic stocks of beaked whales (Blainville's beaked
whale, Gervais' beaked whale, northern bottlenose dolphin, and True's
beaked whale), with the exception of Sowerby's beaked whales and goose-
beaked whales, and thereby unlikely to affect annual rates of
recruitment or survival. For Sowerby's beaked whales and goose-beaked
whales, as described above, we do not anticipate the relatively limited
number of individuals that might be taken over repeated days within the
year in a manner that results in a year of foregone reproduction to
adversely affect either stock through effects on rates of recruitment
or survival, given the statuses of these stocks. For these reasons, we
have determined that the total take (considering annual maxima and
across 7 years) anticipated and authorized will have a negligible
impact on all Western North Atlantic beaked whales.
Beaked Whales (Northern Gulf of America Stocks)
These stocks are not listed as endangered or threatened under the
ESA, and they are not considered depleted or strategic under the MMPA.
The estimated abundances of these stocks of Blainville's beaked whale,
goose-beaked whale, and Gervais' beaked whale are 99, 368, and 386,
respectively, as indicated in the Navy's NMSDD estimates. There are no
known BIAs for beaked whales in the Gulf of America. These stocks all
occur year-round in deep water areas in the Gulf of America and Key
West. Beaked whales in the Gulf of America face several chronic
anthropogenic and non-anthropogenic risk factors, including energy
exploration and development, and entanglement, among others.
As shown in table 54, the maximum annual allowable instances of
take under this rule by Level B harassment are 126, 460, and 125 for
Blainville's beaked whale, goose-beaked whale, and Gervais' beaked
whale, respectively. No mortality is anticipated or authorized, nor is
any auditory or non-auditory injury (Level A harassment). The total
take allowable across all 7 years of the rule is indicated in table 16.
Regarding the potential takes associated with TTS, as described in
the Temporary Threshold Shift section of the proposed rule (90 FR
19858, May 9, 2025), any takes in the form of TTS are expected to be
lower-level, of short duration (from minutes to, at most, several hours
or less than a day), and mostly not in a frequency band that would be
expected to interfere with odontocete echolocation, overlap more than a
relatively narrow portion of the vocalization range of any single
species or stock, or preclude detection or interpretation of important
low-frequency cues. Any associated lost opportunities or capabilities
individuals might experience as a result of TTS would not be at a level
or duration that would be expected to impact reproductive success or
survival.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 154 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Beaked whales
are medium-bodied odontocetes with a medium pace of life and likely
moderately resilient to missed foraging opportunities due to acoustic
disturbance. They are mixed breeders (i.e., behaviorally income
breeders) and they demonstrate capital breeding strategies during
gestation and lactation (Keen et al., 2021), so they may be more
vulnerable to prolonged loss of foraging opportunities during
gestation.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
number of takes by harassment as compared to the stock/species
abundances (see table 54) and the fact that 60-65 percent of the takes
occur around Key West, it is likely that some portion of the
individuals taken are taken repeatedly over a limited number of days.
However, given the variety of activity types that contribute to take
across separate exercises conducted at different times and in different
areas, and the fact that many result from transient activities
conducted at sea, it is unlikely that repeated takes would occur either
in numbers or clumped across sequential days in a manner likely to
impact foraging success and energetics or other behaviors such that
reproduction or survival are likely to be impacted.
Given the magnitude and severity of the impacts discussed above to
Northern Gulf of America stocks of beaked whales (considering annual
take maxima and the total across 7 years) and their habitat, and in
consideration of the other information presented, the Action
Proponents' activities are unlikely to result in impacts on the
reproduction or survival of any individuals and, thereby, unlikely to
affect annual rates of recruitment or survival. Last, we are aware that
some Northern Gulf of America stocks of beaked whales have experienced
lower rates of reproduction and survival since the DWH oil spill;
however, those effects are reflected in the SARs and other data
considered in these analyses and do not change our findings. For these
reasons, we have determined that the take by harassment anticipated and
authorized will have a negligible impact on the Northern Gulf of
America stocks of beaked whales.
Dolphins and Small Whales--
Of the 53 stocks of dolphins and small whales (Delphinidae) for
which incidental take is authorized (see table
[[Page 50676]]
56), none is listed as endangered or threatened under the ESA. Only
spinner dolphins are listed as depleted under the MMPA; however, about
a third of the species are listed as strategic, including 14 stocks of
bottlenose dolphins, Northern Gulf of America stocks of Clymene,
striped, and spinner dolphins, and the Western Northern Atlantic stocks
of spinner dolphins and short-finned pilot whales. As shown in table 56
and table 57, these delphinids vary in stock abundance, body size, and
movement ecology from, for example, the small-bodied, nomadic/migratory
Western North Atlantic white-beaked dolphins that range well beyond the
U.S. EEZ and outside the AFTT Study Area and have a SAR abundance over
500,000, to the medium-sized resident bay stocks of bottlenose dolphins
with abundances under 200, to the large-bodied nomadic Western North
Atlantic killer whale, for which the abundance is unknown. While there
are several small and resident populations of bottlenose dolphins,
there are no other known BIAs (e.g., foraging, reproduction) for any of
these delphinid stocks. Delphinids face a number of chronic
anthropogenic and non-anthropogenic risk factors including biotoxins,
chemical contaminants, fishery interaction, habitat alteration, illegal
feeding/harassment, ocean noise, oil spills and energy exploration,
vessel strikes, and disease, the impacts of which vary depending
whether the stock is more coastal (e.g., biotoxins and some fishing
interactions more seen in bottlenose dolphins), more or less deep-
diving (e.g., entanglement more common in deep divers like pygmy killer
whales and pilot whales), in the Gulf of America (e.g., lingering lower
reproductive rates for some stocks affected by DWH oil spill impacts),
and other behavioral differences (e.g., vessels strikes more concern
for killer whales).
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As shown in table 56, the maximum annual allowable instances of
take by Level B harassment for delphinid stocks range from 1 (Sabine
Lake bottlenose dolphin stock) to 269,405 for the Western North
Atlantic common dolphin, with 26 stocks below 2,000, 7 stocks above
70,000, and the remainder between 2,000 and 38,000. Take by Level A
harassment is 0 for 17 of the 53 stocks, above 15 for 11 stocks, and 11
or fewer for the remaining stocks. As indicated, the rule also allows
for 1-2 takes annually by M/SI for five stocks (the Northern Gulf of
America stocks of striped and pantropical dolphins, the Western North
Atlantic offshore stock of bottlenose dolphins, the Western North
Atlantic South Carolina/Georgia Coastal stock of Tamanend's bottlenose
dolphins, and the Western North Atlantic stock of Clymene dolphins),
the impacts of which are discussed above in the Mortality section. The
total take allowable across all 7 years of the rule is indicated in
table 16.
All but two delphinid stocks are expected to incur some number of
takes in the form of TTS. As described in the Auditory Injury from
Sonar Acoustic Sources and Explosives and Non-Auditory Injury from
Explosives section of the proposed rule (90 FR 19858, May 9, 2025),
these temporary hearing impacts are expected to be lower-level, of
short duration (from minutes to at most several hours or less than a
day), and mostly not in a frequency band that would be expected to
interfere with delphinid echolocation, overlap more than a relatively
narrow portion of the vocalization range of any single species or
stock, or preclude detection or interpretation of important low-
frequency cues. Any associated lost opportunities or capabilities
individuals might experience as a result of TTS would not be at a level
or duration that would be expected to impact reproductive success or
survival. About two-thirds of the affected Delphinid stocks will incur
some number of takes by AUD INJ, the majority of single digits, with
higher numbers exceeding 50 and up to 161 for several stocks. For
reasons similar to those discussed for TTS, while AUD INJ impacts are
permanent, given the anticipated effectiveness of the mitigation and
the likelihood that individuals are expected to avoid higher levels
associated with more severe impacts, the lower anticipated levels of
PTS that could be reasonably expected to result from these activities
are unlikely to affect the fitness of any individuals. Five stocks are
projected to incur notably higher numbers of take by AUD INJ (85-161,
the Western North Atlantic stocks of Atlantic spotted dolphins, common
dolphins, Clymene dolphins, striped dolphins, and offshore bottlenose
dolphins) and while the conclusions above are still applicable, it is
further worth noting that these five stocks have relatively large
abundances and limited annual mortality as compared to PBR. The rule
also allows for a limited number of takes by non-auditory injury (1-3)
for 15 stocks. As described above in the Auditory Injury from Sonar
Acoustic Sources and Explosives and Non-Auditory Injury from Explosives
section of the proposed rule (90 FR 19858, May 9, 2025), given the
limited number of potential exposures and the anticipated effectiveness
of the mitigation measures in minimizing the pressure levels to which
any individuals are exposed, these non-auditory injuries are unlikely
to be of a nature or level that would impact reproduction or survival.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 178 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, foraging
interruptions, vocalization changes, or disruption of other social
behaviors, lasting from a few minutes to several hours. Delphinids are
income breeders with a medium pace of life, meaning that while they can
be sensitive to the consequences of disturbances that impact foraging
during lactation, from a population standpoint, they can be moderately
quick to recover. Further, as described in the Group and Species-
Specific Analyses section above and the Mitigation Measures section,
mitigation measures are expected to further reduce the potential
severity of impacts through real-time operational measures that
minimize higher level/longer duration exposures and time/area measures
that reduce impacts in higher value habitat.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In the case of just over
half of the delphinid stocks (see the Maximum Annual Harassment As
Percentage of Stock Abundance column in table 56), given the low number
of takes by harassment as compared to the stock/species abundance
alone, and also in consideration of their migratory movement pattern
and whether take is concentrated in areas in which animals are known to
congregate, it is unlikely that these individual Delphinids would be
taken on more than a limited number
[[Page 50697]]
of days within a year and, therefore, the anticipated behavioral
disturbance is not expected to affect reproduction or survival. In the
case of the rest of the stocks, with the exception of the Northern
North Carolina Estuarine System stock of bottlenose dolphins (addressed
below), given the number of takes by harassment as compared to the
stock/species abundance, it is likely that some portion of the
individuals taken are taken repeatedly over a small to moderate number
of days (as indicated in the Greatest Degree Any Individual Expected to
be Taken Repeatedly Across Multiple days column of table 56). However,
given the variety of activity types that contribute to take across
separate exercises conducted at different times and in different areas,
and the fact that many result from transient activities conducted at
sea, for all but one of the stocks (addressed below), it is unlikely
that the anticipated small to moderate number of repeated takes for a
given individual would occur clumped across sequential days in a manner
likely to impact foraging success and energetics or other behaviors
such that reproduction or survival of any individuals are likely to be
impacted. Further, many of these stocks are nomadic or migratory and
apart from the few small resident dolphin populations, there are no
known foraging areas or other areas within which animals are known to
congregate for important behaviors, and nor are the takes concentrated
within a specific region and season.
Regarding the magnitude of repeated takes for the Northern North
Carolina Estuarine System stock of bottlenose dolphins, given the
number of takes by harassment as compared to the stock/species
abundance, the small resident population, the fact that the predicted
takes all occur in summer and are primarily from hull-mounted sonar
pierside or navigating out of Norfolk (see appendix A to the
application), it is more likely that some number of individuals
occupying that area during the summer months would experience a
comparatively higher number of repeated takes over a potentially fair
number of sequential days. Due to the higher number of repeated takes
focused within a limited time period, it is thereby more likely that a
portion of the individuals occupying the area near Norfolk in the
summer (approximately 50 percent of which would be female) could be
repeatedly interrupted during foraging in a manner and amount such that
impacts to the energy budgets of a limited number of females (from
either losing feeding opportunities or expending considerable energy
moving away from sound sources or finding alternative feeding options)
could cause them to forego reproduction for a year (noting that
bottlenose dolphin calving intervals are typically 3 or more years).
Energetic impacts to males are generally meaningless to population
rates unless they cause death, and it takes extreme energy deficits
beyond what would ever be likely to result from these activities to
cause the death of an adult marine mammal, male or female. This stock
is considered potentially stable and, while strategic, is not depleted.
Importantly, the increase in a calving interval by a year would have
far less of an impact on a population rate than a mortality would and,
accordingly, a limited number of instances of foregone reproduction
would not be expected to adversely affect this stock through effects on
annual rates of recruitment or survival (noting also that no mortality
is predicted or authorized for this stock).
Given the magnitude and severity of the take by harassment
discussed above and any anticipated habitat impacts, and in
consideration of the required mitigation measures and other information
presented, the Action Proponents' activities are unlikely to result in
impacts on the reproduction or survival of any individuals of delphinid
stocks, with the exception of the five stocks for which one to two
takes by M/SI are predicted and the one stock for which an increased
calving interval could potentially occur. Regarding the Northern North
Carolina Estuarine System stock of bottlenose dolphins, as described
above, we do not anticipate the relatively limited number of
individuals that might be taken over repeated days within the year in a
manner that results in a year of foregone reproduction to adversely
affect the stock through effects on rates of recruitment or survival,
given the status of the stock. Regarding the Northern Gulf of America
stocks of striped and pantropical dolphins, the Western North Atlantic
offshore stock of bottlenose dolphins, the Western North Atlantic South
Carolina/Georgia stock of Tamanend's bottlenose dolphins, and the
Western North Atlantic Clymene dolphins, as described in the Mortality
section, given the status of the stocks and in consideration of other
ongoing anthropogenic mortality, the amount of allowed M/SI take
authorized here would not, alone, nor in combination with the impacts
of the take by harassment discussed above (which are not expected to
impact the reproduction or survival of any individuals for those
stocks), be expected to adversely affect rates of recruitment and
survival. Last, we are aware that some Northern Gulf of America stocks
of delphinids have experienced lower rates of reproduction and survival
since the DWH oil spill; however, those effects are reflected in the
SARs and other data considered in these analyses and do not change our
findings. For these reasons, we have determined that the total take
(considering annual maxima and across 7 years) anticipated and
authorized will have a negligible impact on all delphinid species and
stocks.
Porpoises--
Harbor porpoises are not listed as endangered or threatened under
the ESA, and the Gulf of Maine/Bay of Fundy stock is not considered
depleted or strategic under the MMPA. The stock abundance is 85,765
animals. There are no UMEs or other factors that cause particular
concern for this stock. A small and resident population BIA has been
identified for this stock (LaBrecque et al., 2015). There is no ESA-
designated critical habitat for harbor porpoise, as the species is not
ESA-listed. While the Gulf of Maine/Bay of Fundy stock of harbor
porpoises can be found from Greenland to North Carolina, they are
primarily concentrated in the southern Bay of Fundy and northern Gulf
of Maine during warmer months (summer), and from Maine to New Jersey
during colder months (fall and spring). Harbor porpoises face several
chronic anthropogenic and non-anthropogenic risk factors, including
fishery interaction, and ocean noise.
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As shown in table 58, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment are
147 and
[[Page 50700]]
87,119, respectively. No mortality is anticipated or authorized, nor is
any non-auditory injury. The total take allowable across all 7 years of
the rule is indicated in table 16.
Regarding the potential takes associated with auditory impairment,
as VHF cetaceans, harbor porpoises are more susceptible to auditory
impacts in mid- to high frequencies and from explosives than other
species. As described in the Temporary Threshold Shift section of the
proposed rule (90 FR 19858, May 9, 2025), any takes in the form of TTS
are expected to be lower-level, of short duration (even the longest
recovering in less than a day), and mostly not in a frequency band that
would be expected to interfere with porpoise communication or other
important auditory cues. Any associated lost opportunities or
capabilities individuals might experience as a result of TTS would not
be at a level or duration that would be expected to impact reproductive
success or survival. For similar reasons, while auditory injury impacts
last longer, the low anticipated levels of AUD INJ that could be
reasonably expected to result from these activities are unlikely to
have any effect on fitness.
Harbor porpoises are more susceptible to behavioral disturbance
than other species. They are highly sensitive to many sound sources and
generally demonstrate strong avoidance of most types of acoustic
stressors. The information currently available regarding harbor
porpoises suggests a very low threshold level of response for both
captive (Kastelein et al., 2000; Kastelein et al., 2005) and wild
(Johnston, 2002) animals. Southall et al. (2007) concluded that harbor
porpoises are likely sensitive to a wide range of anthropogenic sounds
at low received levels (approximately 90 to 120 dB). Research and
observations of harbor porpoises for other locations show that this
species is wary of human activity and will display profound avoidance
behavior for anthropogenic sound sources in many situations at levels
down to 120 dB re: 1 [micro]Pa (Southall, 2007). Harbor porpoises
routinely avoid and swim away from large, motorized vessels (Barlow et
al., 1988; Evans et al., 1994; Palka and Hammond, 2001; Polacheck and
Thorpe, 1990). Accordingly, and as described in the Estimated Take of
Marine Mammals section, the threshold for behavioral disturbance is
lower for harbor porpoises, and the number of estimated takes is
higher, with many occurring at lower received levels than other taxa.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 154 dB SPL and last from a
few minutes to a few hours, at most. Associated responses would likely
include avoidance, foraging interruptions, vocalization changes, or
disruption of other social behaviors, lasting from a few minutes to
several hours and not likely to exceed 24 hours.
As small odontocetes and income breeders with a fast pace of life,
harbor porpoises are less resilient to missed foraging opportunities
than larger odontocetes. Although reproduction in populations with a
fast pace of life is more sensitive to foraging disruption, these
populations are quick to recover. Further, as described in the Group
and Species-Specific Analyses section above and the Mitigation Measures
section, mitigation measures are expected to further reduce the
potential severity of impacts through real-time operational measures
that minimize higher level/longer duration exposures and time/area
measures that reduce impacts in high value habitat.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. In this case, given the
number of takes by harassment as compared to the stock/species
abundance (see table 58), the small resident population and
concentration of takes (85 percent) in the Northeast, it is likely that
some portion of the individuals taken are taken repeatedly over a
limited number of days. However, given the variety of activity types
that contribute to take across separate exercises conducted at
different times and in different areas, and the fact that many result
from transient activities conducted at sea, it is unlikely that
repeated takes would occur either in numbers or clumped across
sequential days in a manner likely to impact foraging success and
energetics or other behaviors such that reproduction or survival of any
individuals are likely to be impacted.
Given the magnitude and severity of the impacts discussed above to
harbor porpoises (considering annual take maxima and the total across 7
years) and their habitat, and in consideration of the required
mitigation measures and other information presented, the Action
Proponents' activities are unlikely to result in impacts on the
reproduction or survival of any individuals and, thereby, unlikely to
affect annual rates of recruitment or survival. For these reasons, we
have determined that the take by harassment anticipated and authorized
will have a negligible impact on the Gulf of Maine/Bay of Fundy stock
of harbor porpoises.
Pinnipeds
This section builds on the broader discussion above and brings
together the discussion of the different types and amounts of take that
different stocks will incur, the applicable mitigation for each stock,
and the status and life history of the stocks to support the negligible
impact determinations for each stock. We have already described above
why we believe the incremental addition of the limited number of low-
level auditory injury takes will not have any meaningful effect towards
inhibiting reproduction or survival. We have also described above in
this section the unlikelihood of any masking or habitat impacts having
effects that would impact the reproduction or survival of any of the
individual marine mammals affected by the Action Proponents'
activities. For pinnipeds, there is no predicted non-auditory injury
from explosives for any stock, and no predicted mortality for any
stock. Regarding the severity of individual takes by Level B harassment
by behavioral disturbance for pinnipeds, the majority of these
responses are anticipated to occur at received levels below 172 dB, and
last from a few minutes to a few hours, at most, with associated
responses most likely in the form of moving away from the source,
foraging interruptions, vocalization changes, or disruption of other
social behaviors, lasting from a few minutes to several hours. Because
of the small magnitude and severity of effects for all of the species,
it is not necessary to break out the findings by species or stock.
In table 60 below for pinnipeds, we indicate the total annual
mortality, Level A harassment, Level B harassment, and the maximum
annual harassment as a percentage of stock abundance. In table 61
below, we indicate the status, life history traits, important habitats,
and threats that inform our analysis of the potential impacts of the
estimated take on the affected pinniped stocks.
Gray seal, harbor seal, harp seal, and hooded seal are not listed
as endangered or threatened under the ESA, and these stocks are not
considered depleted or strategic under the MMPA. The abundance
estimates for both Western North Atlantic gray seals and harbor seals
are 27,911 and 61,336, but both of those estimates are for the U.S.
portion of the stock only, while each stock's range extends into
Canada. The
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estimated abundance of Western North Atlantic harp seals is 7,600,600,
and a current abundance estimate for hooded seals is not available,
though the most recent SAR (2018; Hayes et al., 2019) estimated an
abundance of 593,500 individuals. The range of both harp seals and
hooded seals also extends into Canada. In 2018, NMFS declared a UME
affecting both gray seals and harbor seals (Northeast Pinniped UME, see
Unusual Mortality Events section), but the UME is currently non-active
and pending closure, with infectious disease determined to be the cause
of the UME. The only known important areas for pinnipeds in the AFTT
Study Area are known gray whale pupping areas on: Green Island, Maine;
Seal Island, Maine; and Muskeget Island, Maine. Pinnipeds in the AFTT
Study Area face several chronic anthropogenic and non-anthropogenic
risk factors, including entanglement, and disease, among others.
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As shown in table 60, the maximum annual allowable instances of
take under this rule by Level A harassment and Level B harassment range
from 2
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(hooded seal) to 32 (harbor seal) and 1,726 (hooded seal) to 25,792
(harp seal), respectively. No mortality is anticipated or authorized,
nor is any non-auditory injury. The total take allowable across all 7
years of the rule for each stock is indicated in table 16.
Regarding the potential takes associated with auditory impairment,
as described in the Temporary Threshold Shift section of the proposed
rule (90 FR 19858, May 9, 2025), any takes in the form of TTS are
expected to be lower-level, of short duration, and mostly not in a
frequency band that would be expected to interfere with pinniped
communication or other important low-frequency cues. Any associated
lost opportunities or capabilities individuals might experience as a
result of TTS would not be at a level or duration that would be
expected to impact reproductive success or survival. For similar
reasons, while auditory injury impacts last longer, the low anticipated
levels of AUD INJ that could be reasonably expected to result from
these activities are unlikely to have any effect on fitness.
Regarding the likely severity of any single instance of take by
behavioral disturbance, as described above, the majority of the
predicted exposures are expected to be below 172 dB SPL and last from a
few minutes to a few hours, at most, with associated responses most
likely in the form of moving away from the source, increased swimming
speeds, increased surfacing time, or foraging interruptions, lasting
from a few minutes to several hours. Pinnipeds have a fast pace of life
but have a relatively lower energy requirement for their body size,
which may moderate any impact due to foraging disruption. However, harp
seals have a large inter-annual variability in reproductive rates due
to variations in prey abundance (rely primarily on capelin as their
preferred prey) and mid-winter ice coverage and may not reproduce as
quickly as other pinnipeds. Also of note, gray seals are likely to be
exposed to Navy noise sources when in their more southern habitats in
the northeast region, especially in colder months when they breed and
give birth.
As described above, in addition to evaluating the anticipated
impacts of the single instances of takes, it is important to understand
the degree to which individual marine mammals may be disturbed
repeatedly across multiple days of the year. For gray seals and harbor
seals the SARs do not provide stock abundances that reflect the full
ranges of the stocks. For hooded seals, the SAR does not provide an up-
to-date abundance estimate for any portion of the stock's range. The
Navy's NMSDD abundance estimate for hooded seals was 1,097; however,
this estimate appears to be underestimated by several orders of
magnitude, as the most recent SAR estimate (2018 SAR; Hayes et al.
2019) was 593,500 animals. For all pinniped species, given the lower
number of takes by harassment as compared to the stock/species
abundance (accounting for the factors described above regarding
abundance estimates; see table 60) and their migratory or nomadic-
migratory movement patterns, it is unlikely that any individual
pinnipeds would be taken on more than a limited number of days within a
year and, therefore, the anticipated behavioral disturbance is not
expected to affect reproduction or survival.
Given the magnitude and severity of the impacts discussed above
(considering annual maxima and across 7 years) and in consideration of
the required mitigation measures and other information presented, for
each pinniped stock, the Action Proponents' activities are not expected
to result in impacts on the reproduction or survival of any
individuals, much less affect annual rates of recruitment or survival.
Last, we have both considered the effects of the Northeast Pinniped
UME, pending closure, in our analysis and findings regarding the impact
of the activity on these stocks and also determined that we do not
expect the authorized take to exacerbate the effects of the UME or
otherwise impact the populations. For these reasons, we have determined
that the take by harassment anticipated and authorized will have a
negligible impact on all pinniped stocks.
Determination
Based on the analysis contained herein of the likely effects of the
specified activities on marine mammals and their habitat, and taking
into consideration the implementation of the required monitoring and
mitigation measures, NMFS finds that the total marine mammal take from
the specified activity will have a negligible impact on all affected
marine mammal species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
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 AFTT Study Area: blue whale, fin whale,
NARW, Rice's whale, sei whale, and sperm whale. The NARW has critical
habitat designated under the ESA in the AFTT Study Area (81 FR 4837,
February 26, 2016) and the Rice's whale has proposed critical habitat
in the AFTT Study Area (88 FR 47453, July 24, 2023).
The Action Proponents consulted with NMFS pursuant to section 7 of
the ESA for AFTT activities, and NMFS also consulted internally on the
promulgation of this rule and the issuance of LOAs under section
101(a)(5)(A) of the MMPA. NMFS issued a biological and conference
opinion concluding that the promulgation of the rule and issuance of
subsequent LOAs are not likely to jeopardize the continued existence of
threatened and endangered species under NMFS' jurisdiction and are not
likely to result in the destruction or adverse modification of
designated or proposed critical habitat in the AFTT Study Area. The
biological and conference opinion is available at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
National Marine Sanctuaries Act
Federal agency actions that are likely to injure sanctuary
resources are subject to consultation with NOAA's Office of National
Marine Sanctuaries (ONMS) under section 304(d) of the National Marine
Sanctuaries Act (NMSA) (16 U.S.C. 1431 et seq.).
On November 20, 2024, NMFS and the Action Proponents jointly
requested consultation with NOAA's ONMS to fulfill our responsibilities
under the NMSA, as warranted. At that time, NMFS and the Action
Proponents submitted a Sanctuary Resource Statement (SRS), as the
Action Proponents concluded that their training and testing activities
in the AFTT Study Area will likely injure sanctuary resources that
reside within Gerry E. Studds Stellwagen Bank NMS, Gray's Reef NMS,
Florida Keys NMS, and Hudson Canyon proposed NMS arising from sound and
other environmental stressors, and NMFS concluded that proposed MMPA
[[Page 50705]]
regulations and associated LOAs that would allow the Action Proponents
to incidentally take marine mammals include a subset of those impacts
that could occur to NMS resources.
ONMS reviewed the SRS and found the SRS sufficient for the purposes
of making an injury determination and developing recommended
alternatives as required by the NMSA. On March 14, 2025, ONMS concurred
with NMFS and the Action Proponents' joint injury determination for the
above mentioned sanctuaries that were subject to consultation and did
not provide additional recommended alternatives. On April 15, 2025,
NMFS and the Navy submitted a joint response concluding consultation
under the NMSA.
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 review our proposed actions with respect to potential impacts
on the human environment. NMFS participated as a cooperating agency on
the 2025 AFTT Supplemental EIS/OEIS, which was published on August 15,
2025 (90 FR 39392), and is available at: https://www.nepa.navy.mil/aftteis/. Pursuant to NAO 216-6A and its accompanying Companion Manual
(as amended), NMFS independently reviewed and evaluated the 2025 AFTT
Supplemental EIS/OEIS and determined that it is adequate and sufficient
to meet our responsibilities under NEPA for the issuance of this rule
and associated LOAs. NOAA, therefore, has adopted the 2025 AFTT
Supplemental EIS/OEIS. NMFS has prepared a separate Record of Decision.
NMFS' Record of Decision for adoption of the 2025 AFTT Supplemental
EIS/OEIS and issuance of this final rule and subsequent LOAs can be
found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
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 during the
proposed rule stage that this action would not have a significant
economic impact on a substantial number of small entities. The factual
basis for the certification was published in the proposed rule and is
not repeated here. No comments were received regarding this
certification. As a result, a final regulatory flexibility analysis was
not required and none was prepared.
Paperwork Reduction Act
This action does not contain any collection of information
requirements for purposes of the Paperwork Reduction Act of 1980 (44
U.S.C. 3501 et seq.).
Executive Order 12866
The Office of Management and Budget has determined that this rule
is not significant for purposes of Executive Order 12866.
Executive Order 14192
This final rule is not an Executive Order 14192 regulatory action
because this action is not significant under Executive Order 12866.
Waiver of Delay in Effective Date
NMFS has determined that there is good cause under the
Administrative Procedure Act (APA) (5 U.S.C. 553(d)(3)) to waive the
30-day delay in the effective date of this final rule. No individual or
entity other than the Action Proponents are affected by the provisions
of these regulations. The Action Proponents have requested that this
final rule take effect on or before November 14, 2025, to accommodate
the Navy's LOAs that expire on November 13, 2025, so as to not cause a
disruption in training and testing activities. The waiver of the 30-day
delay of the effective date of the final rule will ensure that the MMPA
final rule and LOAs are in place by the time the previous
authorizations expire. Any delay in effectiveness of the final rule
would result in either: (1) a suspension of planned naval training and
testing, which would disrupt vital training and testing essential to
national security; or (2) the Action Proponents' procedural non-
compliance with the MMPA (should the Action Proponents conduct training
and testing without LOAs), thereby resulting in the potential for
unauthorized takes of marine mammals. Moreover, the Action Proponents
are ready to implement the regulations immediately. For these reasons,
NMFS finds good cause to waive the 30-day delay in the effective date.
In addition, the rule authorizes incidental take of marine mammals that
would otherwise be prohibited under the statute. Therefore, by granting
an exception to the Action Proponents, the rule relieves restrictions
under the MMPA, which provides a separate basis for waiving the 30-day
effective date for the rule under section 553(d)(1) of the APA.
List of Subjects in 50 CFR Part 218
Administrative practice and procedure, Endangered and threatened
species, Fish, Fisheries, Marine mammals, Penalties, Reporting and
recordkeeping requirements, Transportation, Wildlife.
Dated: November 4, 2025.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
For the reasons set forth in the preamble, NMFS amends 50 CFR part
218 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.
0
2. Revise subpart I to read as follows:
Subpart I--Taking and Importing Marine Mammals; Military Readiness
Activities in the Atlantic Fleet Training and Testing Study Area
Sec.
218.80 Specified activity and geographical region.
218.81 Effective dates.
218.82 Permissible methods of taking.
218.83 Prohibitions.
218.84 Mitigation requirements.
218.85 Requirements for monitoring and reporting.
218.86 Letters of Authorization.
218.87 Modifications of Letters of Authorization.
218.88-218.89 [Reserved]
Sec. 218.80 Specified activity and geographical region.
(a) Regulations in this subpart apply only to the U.S. Navy (Navy)
and U.S. Coast Guard (Coast Guard) (collectively referred to as the
``Action Proponents'') 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.
Requirements imposed on the Action Proponents must be implemented by
those persons they authorize or fund to conduct activities on their
behalf.
(b) The taking of marine mammals by the Action Proponents under
this subpart may be authorized in letters of authorization (LOAs) only
if it occurs within the Atlantic Fleet Training and Testing (AFTT)
Study Area. The AFTT Study Area includes areas of the western Atlantic
Ocean along the east coast of North America, the Gulf of America, and
portions of the Caribbean
[[Page 50706]]
Sea, covering approximately 2.6 million nmi\2\ (8.9 million km\2\) of
ocean, oriented from the mean high tide line along the U.S. coast and
extending east to 45[deg] W longitude line, north to 65[deg] N latitude
line, and south to approximately the 20[deg] N latitude line. It also
includes Navy and Coast Guard pierside locations, port transit
channels, bays, harbors, inshore waterways (e.g., channels, rivers),
civilian ports where military readiness activities occur, and vessel
and aircraft transit routes among homeports, designated operating areas
(OPAREAs), and testing and training ranges.
BILLING CODE 3510-22-P
[[Page 50707]]
Figure 1 to Paragraph (b)--Map of the AFTT Study Area
[GRAPHIC] [TIFF OMITTED] TR07NO25.132
[[Page 50708]]
BILLING CODE 3510-22-C
(c) The taking of marine mammals by the Action Proponents is only
authorized if it occurs incidental to the Action Proponents conducting
military readiness activities, including those in the following
categories:
(1) Amphibious warfare;
(2) Anti-submarine warfare;
(3) Expeditionary warfare;
(4) Mine warfare;
(5) Surface warfare;
(6) Vessel evaluation;
(7) Unmanned systems;
(8) Acoustic and oceanographic science and technology;
(9) Vessel movement; and
(10) Other training and testing activities.
Sec. 218.81 Effective dates.
Regulations in this subpart are effective from November 14, 2025,
through November 13, 2032.
Sec. 218.82 Permissible methods of taking.
(a) Under LOAs issued pursuant to Sec. 216.106 of this chapter and
this subpart, the Action Proponents may incidentally, but not
intentionally, take marine mammals within the area described in Sec.
218.80(b) by Level A harassment and Level B harassment associated with
the use of active sonar and other acoustic sources and explosives, as
well as serious injury or mortality associated with vessel strikes and
explosives, provided the activity is in compliance with all terms,
conditions, and requirements of this subpart and the applicable LOAs.
(b) The incidental take of marine mammals by the activities listed
in Sec. 218.80(c) is limited to the following species:
Table 1 to Paragraph (b)
------------------------------------------------------------------------
Species Stock
------------------------------------------------------------------------
North Atlantic right whale............. Western.
Blue whale............................. Western North Atlantic.
Bryde's whale.......................... Primary.
Fin whale.............................. Western North Atlantic.
Humpback whale......................... Gulf of Maine.
Minke whale............................ Canadian Eastern Coast.
Rice's whale........................... Northern Gulf of America.
Sei whale.............................. Nova Scotia.
Sperm whale............................ North Atlantic.
Sperm whale............................ Northern Gulf of America.
Dwarf sperm whale...................... Northern Gulf of America.
Pygmy sperm whale...................... Northern Gulf of America.
Dwarf sperm whale...................... Western North Atlantic.
Pygmy sperm whale...................... Western North Atlantic.
Blainville's beaked whale.............. Northern Gulf of America.
Goose-beaked whale..................... Northern Gulf of America.
Gervais' beaked whale.................. Northern Gulf of America.
Blainville's beaked whale.............. Western North Atlantic.
Goose-beaked whale..................... Western North Atlantic.
Gervais' beaked whale.................. Western North Atlantic.
Northern bottlenose whale.............. Western North Atlantic.
Sowerby's beaked whale................. Western North Atlantic.
True's beaked whale.................... Western North Atlantic.
Atlantic spotted dolphin............... Northern Gulf of America.
Bottlenose dolphin..................... Gulf of America Eastern
Coastal.
Bottlenose dolphin..................... Gulf of America Northern
Coastal.
Bottlenose dolphin..................... Gulf of America, Oceanic.
Bottlenose dolphin..................... Gulf of America Western
Coastal.
Bottlenose dolphin..................... Mississippi Sound, Lake Borgne,
and Bay Boudreau.
Bottlenose dolphin..................... Northern Gulf of America
Continental Shelf.
Bottlenose dolphin..................... Nueces and Corpus Christi Bays.
Bottlenose dolphin..................... Sabine Lake.
Bottlenose dolphin..................... St. Andrew Bay.
Bottlenose dolphin..................... St. Joseph Bay.
Bottlenose dolphin..................... Tampa Bay.
Clymene dolphin........................ Northern Gulf of America.
False killer whale..................... Northern Gulf of America.
Fraser's dolphin....................... Northern Gulf of America.
Killer whale........................... Northern Gulf of America.
Melon-headed whale..................... Northern Gulf of America.
Pygmy killer whale..................... Northern Gulf of America.
Risso's dolphin........................ Northern Gulf of America.
Rough-toothed dolphin.................. Northern Gulf of America.
Short-finned pilot whale............... Northern Gulf of America.
Striped dolphin........................ Northern Gulf of America.
Pantropical spotted dolphin............ Northern Gulf of America.
Spinner dolphin........................ Northern Gulf of America.
Atlantic white-sided dolphin........... Western North Atlantic.
Common dolphin......................... Western North Atlantic.
Atlantic spotted dolphin............... Western North Atlantic.
Bottlenose dolphin..................... Indian River Lagoon Estuarine
System.
Bottlenose dolphin..................... Jacksonville Estuarine System.
Bottlenose dolphin..................... Northern Georgia/Southern South
Carolina Estuarine System.
Bottlenose dolphin..................... Northern North Carolina
Estuarine System.
Bottlenose dolphin..................... Southern Georgia Estuarine
System.
[[Page 50709]]
Bottlenose dolphin..................... Southern North Carolina
Estuarine System.
Tamanend's bottlenose dolphin.......... Western North Atlantic Central
Florida Coastal.
Tamanend's bottlenose dolphin.......... Western North Atlantic Northern
Florida Coastal.
Bottlenose dolphin..................... Western North Atlantic Northern
Migratory Coastal.
Bottlenose dolphin..................... Western North Atlantic
Offshore.
Tamanend's bottlenose dolphin.......... Western North Atlantic South
Carolina/Georgia Coastal.
Bottlenose dolphin..................... Western North Atlantic Southern
Migratory Coastal.
Clymene dolphin........................ Western North Atlantic.
False killer whale..................... Western North Atlantic.
Fraser's dolphin....................... Western North Atlantic.
Killer whale........................... Western North Atlantic.
Long-finned pilot whale................ Western North Atlantic.
Melon-headed whale..................... Western North Atlantic.
Pantropical spotted dolphin............ Western North Atlantic.
Pygmy killer whale..................... Western North Atlantic.
Risso's dolphin........................ Western North Atlantic.
Rough-toothed dolphin.................. Western North Atlantic.
Short-finned pilot whale............... Western North Atlantic.
Spinner dolphin........................ Western North Atlantic.
Striped dolphin........................ Western North Atlantic.
White-beaked dolphin................... Western North Atlantic.
Harbor porpoise........................ Gulf of Maine/Bay of Fundy.
Gray seal.............................. Western North Atlantic.
Harbor seal............................ Western North Atlantic.
Harp seal.............................. Western North Atlantic.
Hooded seal............................ Western North Atlantic.
------------------------------------------------------------------------
Sec. 218.83 Prohibitions.
Except incidental take described in Sec. 218.82 and authorized by
a LOA issued under this subpart, it shall be unlawful for any person to
do the following in connection with the activities described in this
subpart:
(a) Violate, or fail to comply with, the terms, conditions, and
requirements of this subpart or a LOA issued under Sec. 216.106 of
this chapter and this subpart;
(b) Take any marine mammal not specified in Sec. 218.82(b);
(c) Take any marine mammal specified in Sec. 218.82(b) in any
manner other than as specified in the LOAs; or
(d) Take a marine mammal specified in Sec. 218.82(b) after NMFS
determines such taking results in more than a negligible impact on the
species or stock of such marine mammal.
Sec. 218.84 Mitigation requirements.
(a) When conducting the activities identified in Sec. 218.80(c),
the mitigation measures contained in this section and any LOA issued
under this subpart must be implemented by Action Proponent personnel or
contractors who are trained according to the requirements in the LOA.
If Action Proponent contractors are serving on behalf of Action
Proponent personnel, Action Proponent contractors must follow the
mitigation applicable to Action Proponent personnel. These mitigation
measures include, but are not limited to:
(1) Activity-based mitigation. Activity-based mitigation is
mitigation that the Action Proponents must implement whenever and
wherever an applicable military readiness activity takes place within
the AFTT Study Area. The Action Proponents must implement the
mitigation described in paragraphs (a)(1)(i) through (xxii) of this
section, except as provided in paragraph (a)(1)(xxiii) of this section.
(i) Active acoustic sources with power down and shut down
capabilities. For active acoustic sources with power down and shutdown
capabilities (low-frequency active sonar >=200 decibels (dB), mid-
frequency active sonar sources that are hull mounted on a surface ship
(including surfaced submarines), and broadband and other active
acoustic sources >200 dB):
(A) Mitigation zones and requirements. During use of active
acoustic sources with power down and shutdown capabilities, the
following mitigation zone requirements apply:
(1) Within 1,000 yards (yd; 914.4 meters (m)) from a marine mammal,
Action Proponent personnel must power down active acoustic sources by 6
dB total.
(2) Within 500 yd (457.2 m) from a marine mammal, Action Proponent
personnel must power down active acoustic sources by an additional 4 dB
(10 dB total).
(3) Within 200 yd (182.9 m) from a marine mammal, Action Proponent
personnel must shut down active acoustic sources.
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout in or on one of the following: aircraft; pierside,
moored, or anchored vessel; underway vessel with space/crew
restrictions (including small boats); or underway vessel already
participating in the event that is escorting (and has positive control
over sources used, deployed, or towed by) an unmanned platform.
(2) Two Lookouts on an underway vessel without space or crew
restrictions.
(3) Lookouts must use information from passive acoustic detections
to inform visual observations when passive acoustic devices are already
being used in the event.
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals and floating vegetation immediately
prior to the initial start of use of active acoustic sources (e.g.,
while maneuvering on station).
(2) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals during use of active acoustic
sources.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of
[[Page 50710]]
the commencement or recommencement conditions in paragraph (a)(1)(xxi)
of this section is met prior to the initial start of the activity (by
delaying the start) or during the activity (by not recommencing or
powering up active sonar transmission). The wait period for this
activity is 30 minutes for activities conducted from vessels and for
activities conducted by aircraft that are not fuel constrained and 10
minutes for activities involving aircraft that are fuel constrained
(e.g., rotary-wing aircraft, fighter aircraft).
(ii) Active acoustic sources with shut down capabilities only (no
power down capability). For active acoustic sources with shut down
capabilities only (no power down capability) (low-frequency active
sonar <200 dB, mid-frequency active sonar sources that are not hull
mounted on a surface ship (e.g., dipping sonar, towed arrays), high-
frequency active sonar, air guns, and broadband and other active
acoustic sources <200 dB):
(A) Mitigation zones and requirements. During use of active
acoustic sources with shut down capabilities only, the following
mitigation zone requirements apply:
(1) At 200 yd (182.9 m) from a marine mammal, Action Proponent
personnel must shut down active acoustic sources.
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout in or on one of the following: aircraft; pierside,
moored, or anchored vessel; underway vessel with space/crew
restrictions (including small boats); or underway vessel already
participating in the event that is escorting (and has positive control
over sources used, deployed, or towed by) an unmanned platform.
(2) Two Lookouts on an underway vessel without space or crew
restrictions.
(3) Lookouts must use information from passive acoustic detections
to inform visual observations when passive acoustic devices are already
being used in the event.
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals and floating vegetation immediately
prior to the initial start of use of active acoustic sources (e.g.,
while maneuvering on station).
(2) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals during use of active acoustic
sources.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing or powering up active sonar
transmission). The wait period for this activity is 30 minutes for
activities conducted from vessels and for activities conducted by
aircraft that are not fuel constrained and 10 minutes for activities
involving aircraft that are fuel constrained (e.g., rotary-wing
aircraft, fighter aircraft).
(iii) Pile driving and extraction. For pile driving and extraction:
(A) Mitigation zones and requirements. During vibratory and impact
pile driving and extraction, the following mitigation zone requirements
apply:
(1) Action Proponent personnel must cease pile driving or
extraction if a marine mammal is sighted within 100 yd (91.4 m) of a
pile being driven or extracted.
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout in or on one of the following: shore, pier, or
small boat.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals and floating vegetation for 15 minutes prior to the
initial start of pile driving or pile extraction.
(2) Action Proponent personnel must use soft start standard
operating procedures when impact pile driving. Soft start requires the
Action Proponent to conduct three sets of strikes (three strikes per
set) at reduced hammer energy with a 30-second waiting period between
each set. A soft start must be implemented at the start of each day's
impact pile driving and at any time following cessation of impact pile
driving for a period of 30 minutes or longer.
(3) Action Proponent personnel must observe the mitigation zone for
marine mammals during pile driving or extraction.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing vibratory or impact pile driving or
extraction). The wait period for this activity is 15 minutes.
(iv) Weapons firing noise. For weapons firing noise:
(A) Mitigation zones and requirements. During explosive and non-
explosive large-caliber (57 millimeter (mm) and larger) gunnery firing
noise (surface-to-surface and surface-to-air), the following mitigation
zone requirements apply:
(1) Action Proponent personnel must cease weapons firing if a
marine mammal is sighted within 30 degrees on either side of the firing
line out to 70 yd (64 m) from the gun muzzle (cease fire).
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout on a vessel.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals and floating vegetation immediately prior to the initial
start of large-caliber gun firing (e.g., during target deployment).
(2) Action Proponent personnel must observe the mitigation zone for
marine mammals during large-caliber gun firing.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing explosive and non-explosive large-caliber
gunnery firing noise (surface-to-surface and surface-to-air)). The wait
period for this activity is 30 minutes.
(v) Explosive bombs. For explosive bombs:
(A) Mitigation zones and requirements. During the use of explosive
bombs of any net explosive weight (NEW), the following mitigation zone
requirements apply:
(1) Action Proponent personnel must cease use of explosive bombs if
a marine mammal is sighted within 2,500 yd (2,286 m) from the intended
target.
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout in an aircraft.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
[[Page 50711]]
(1) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals and floating vegetation immediately
prior to the initial start of bomb delivery (e.g., when arriving on
station).
(2) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals during bomb delivery. If a marine
mammal is visibly injured or killed as a result of detonation, use of
explosives in the event must be suspended immediately.
(3) After the event, when practical, Action Proponent personnel
must observe the detonation vicinity for injured or dead marine
mammals. If any injured or dead marine mammals are observed, Action
Proponent personnel must follow established incident reporting
procedures (the Notification and Reporting Plan is available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities).
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing use of explosive bombs of any NEW). The
wait period for this activity is 10 minutes.
(vi) Explosive gunnery. For explosive gunnery:
(A) Mitigation zones and requirements. During the use of air-to-
surface medium-caliber ordnance (larger than 50 caliber and less than
57 mm), surface-to-surface medium-caliber ordnance, and surface-to-
surface large-caliber ordnance, the following mitigation zone
requirements apply:
(1) Action Proponent personnel must cease use of air-to-surface
medium-caliber ordnance if a marine mammal is sighted within 200 yd
(182.9 m) of the intended impact location.
(2) Action Proponent personnel must cease use of surface-to-surface
medium-caliber ordnance if a marine mammal is sighted within 600 yd
(548.6 m) of the intended impact location.
(3) Action Proponent personnel must cease use of surface-to-surface
large-caliber ordnance if a marine mammal is sighted within 1,000 yd
(914.4 m) of the intended impact location.
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout on a vessel or in an aircraft.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals and floating vegetation immediately
prior to the initial start of gun firing (e.g., while maneuvering on
station).
(2) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals during gunnery fire. If a marine
mammal is visibly injured or killed as a result of detonation, use of
explosives in the event must be suspended immediately.
(3) After the event, when practical, Action Proponent personnel
must observe the detonation vicinity for injured or dead marine
mammals. If any injured or dead marine mammals are observed, Action
Proponent personnel must follow established incident reporting
procedures.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing air-to-surface medium-caliber, surface-
to-surface medium-caliber, surface-to-surface large-caliber explosive
gunnery). The wait period for this activity is 30 minutes for
activities conducted from vessels and for activities conducted by
aircraft that are not fuel constrained and 10 minutes for activities
involving aircraft that are fuel constrained (e.g., rotary-wing
aircraft, fighter aircraft).
(vii) Explosive line charges. For explosive line charges:
(A) Mitigation zones and requirements. During the use of explosive
line charges of any NEW, the following mitigation zone requirements
apply:
(1) Action Proponent personnel must cease use of explosive line
charges if a marine mammal is sighted within 900 yd (823 m) of the
detonation site.
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout on a vessel.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals and floating vegetation immediately prior to the initial
start of detonations (e.g., while maneuvering on station).
(2) Action Proponent personnel must observe the mitigation zone for
marine mammals during detonations. If a marine mammal is visibly
injured or killed as a result of detonation, use of explosives in the
event must be suspended immediately.
(3) After the event, when practical, Action Proponent personnel
must observe the detonation vicinity for injured or dead marine
mammals. If any injured or dead marine mammals are observed, Action
Proponent personnel must follow established incident reporting
procedures.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing use of explosive line charges of any
NEW). The wait period for this activity is 30 minutes.
(viii) Explosive mine countermeasure and neutralization (no
divers). For explosive mine countermeasure and neutralization (no
divers):
(A) Mitigation zones and requirements. During explosive mine
countermeasure and neutralization using 0.1-5 pound (lb) (0.05-2.3
kilogram (kg)) NEW and >5 lb (2.3 kg) NEW, the following mitigation
zone requirements apply:
(1) Action Proponent personnel must cease use of 0.1-5 lb (0.05-2.3
kg) NEW if a marine mammal is sighted within 600 yd (548.6 m) from the
detonation site.
(2) Action Proponent personnel must cease use of >5 lb (2.3 kg) NEW
if a marine mammal is sighted within 2,100 yd (1,920.2 m) from the
detonation site.
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout on a vessel or in an aircraft during 0.1-5 lb
(0.05-2.3 kg) NEW use.
(2) Two Lookouts, one on a small boat and one in an aircraft during
>5 lb (2.3 kg) NEW use.
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals and floating vegetation immediately
prior to the initial start of detonations (e.g., while maneuvering on
station; typically, 10 or 30 minutes depending on fuel constraints).
(2) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals during detonations
[[Page 50712]]
or fuse initiation. If a marine mammal is visibly injured or killed as
a result of detonation, use of explosives in the event must be
suspended immediately.
(3) After the event, when practical, Action Proponent personnel
must observe the detonation vicinity for 10 or 30 minutes (depending on
fuel constraints) for injured or dead marine mammals. If any injured or
dead marine mammals are observed, Action Proponent personnel must
follow established incident reporting procedures.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing explosive mine countermeasure and
neutralization using 0.1-5 lb (0.05-2.3 kg) NEW and >5 lb (2.3 kg)
NEW). The wait period for this activity is 30 minutes for activities
conducted from vessels and for activities conducted by aircraft that
are not fuel constrained and 10 minutes for activities involving
aircraft that are fuel constrained (e.g., rotary-wing aircraft, fighter
aircraft).
(ix) Explosive mine neutralization (with divers). For explosive
mine neutralization (with divers):
(A) Mitigation zones and requirements. During explosive mine
neutralization (with divers) using 0.1-20 lb (0.05-9.1 kg) NEW
(positive control), 0.1-20 lb (0.05-9.1 kg) NEW (time-delay), and >20-
60 lb (9.1-27.2 kg) NEW (positive control), the following mitigation
zone requirements apply:
(1) Action Proponent personnel must cease use of 0.1-20 lb (0.05-
9.1 kg) NEW (positive control) if a marine mammal is sighted within 500
yd (457.2 m) of the detonation site (cease fire).
(2) Action Proponent personnel must cease use of 0.1-20 lb (0.05-
9.1 kg) NEW (time-delay) and >20-60 lb (9.1-27.2 kg) NEW (positive
control) if a marine mammal is sighted within 1,000 yd (914.4 m) of the
detonation site (cease fire).
(B) Lookout requirements. The following Lookout requirements apply:
(1) Two Lookouts in two small boats (one Lookout per boat) or one
small boat and one rotary-wing aircraft (with one Lookout each) during
use of 0.1-20 lb (0.05-9.1 kg) NEW (positive control).
(2) Four Lookouts in two small boats (two Lookouts per boat) and
one additional Lookout in an aircraft if used in the event during use
of 0.1-20 lb (0.05-9.1 kg) NEW (time-delay) and >20-60 lb (9.1-27.2 kg)
NEW (positive control).
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Time-delay devices must be set not to exceed 10 minutes.
(2) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals and floating vegetation immediately
prior to the initial start of detonations or fuse initiation for
positive control events (e.g., while maneuvering on station) or for 30
minutes prior for time-delay events.
(3) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals, during detonations or fuse
initiation. If a marine mammal is visibly injured or killed as a result
of detonation, use of explosives in the event must be suspended
immediately.
(4) When practical based on mission, safety, and environmental
conditions: (i) Boats must observe from the mitigation zone radius mid-
point.
(ii) When two boats are used, boats must observe from opposite
sides of the mine location.
(iii) Platforms must travel a circular pattern around the mine
location.
(iv) Boats must have one Lookout observe inward toward the mine
location and one Lookout observe outward toward the mitigation zone
perimeter.
(v) Divers must be part of the Lookout Team.
(5) After the event, when practical, Action Proponent personnel
must observe the detonation vicinity for 30 minutes for injured or dead
marine mammals. If any injured or dead marine mammals are observed,
Action Proponent personnel must follow established incident reporting
procedures.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing explosive mine neutralization (with
divers) using 0.1-20 lb (0.05-9.1 kg) NEW (positive control), 0.1-20 lb
(0.05-9.1 kg) NEW (time-delay), and >20-60 lb (9.1-27.2 kg) NEW
(positive control)). The wait period for this activity is 30 minutes
for activities conducted from vessels and for activities conducted by
aircraft that are not fuel constrained and 10 minutes for activities
involving aircraft that are fuel constrained (e.g., rotary-wing
aircraft, fighter aircraft).
(x) Explosive missiles and rockets. For explosive missiles and
rockets:
(A) Mitigation zones and requirements. During the use of explosive
missiles and rockets using 0.6-20 lb (0.3-9.1 kg) NEW (air-to-surface)
and >20-500 lb (9.1-226.8 kg) NEW (air-to-surface), the following
mitigation zone requirements apply:
(1) Action Proponent personnel must cease use of 0.6-20 lb (0.3-9.1
kg) NEW (air-to-surface) if a marine mammal is sighted within 900 yd
(823 m) of the intended impact location (cease fire).
(2) Action Proponent personnel must cease use of >20-500 lb (9.1-
226.8 kg) NEW (air-to-surface) if a marine mammal is sighted within
2,000 yd (1,828.8 m) of the intended impact location (cease fire).
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout in an aircraft.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals and floating vegetation immediately
prior to the initial start of missile or rocket delivery (e.g., during
a fly-over of the mitigation zone).
(2) Action Proponent personnel must observe the applicable
mitigation zone for marine mammals during missile or rocket delivery.
If a marine mammal is visibly injured or killed as a result of
detonation, use of explosives in the event must be suspended
immediately.
(3) After the event, when practical, Action Proponent personnel
must observe the detonation vicinity for injured or dead marine
mammals. If any injured or dead marine mammals are observed, Action
Proponent personnel must follow established incident reporting
procedures.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing use of explosive missiles and rockets
using 0.6-20 lb (0.3-9.1 kg) NEW (air-to-surface) and >20-500 lb (9.1-
226.8 kg) NEW (air-to-surface)). The wait period for this activity is
30 minutes for activities conducted from vessels and for activities
conducted by aircraft that are not fuel constrained and 10 minutes for
activities involving
[[Page 50713]]
aircraft that are fuel constrained (e.g., rotary-wing aircraft, fighter
aircraft).
(xi) Explosive sonobuoys and research-based sub-surface explosives.
For explosive sonobuoys and research-based sub-surface explosives:
(A) Mitigation zones and requirements. During the use of any NEW of
explosive sonobuoys and 0.1-5 lb (0.05-2.3 kg) NEW for other types of
sub-surface explosives used in research applications, the following
mitigation zone requirements apply:
(1) Action Proponent personnel must cease use of any NEW of
sonobuoys and 0.1-5 lb (0.05-2.3 kg) NEW for other types of sub-surface
explosives used in research applications if a marine mammal is sighted
within 600 yd (548.6 m) of the device or detonation sites (cease fire).
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout on a small boat or in an aircraft.
(2) Conduct passive acoustic monitoring for marine mammals; use
information from detections to assist visual observations.
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals and floating vegetation immediately prior to the initial
start of detonations (e.g., during sonobuoy deployment, which typically
lasts 20-30 minutes).
(2) Action Proponent personnel must observe the mitigation zone for
marine mammals during detonations. If a marine mammal is visibly
injured or killed as a result of detonation, use of explosives in the
event must be suspended immediately.
(3) After the event, when practical, Action Proponent personnel
must observe the detonation vicinity for injured or dead marine
mammals. If any injured or dead marine mammals are observed, Action
Proponent personnel must follow established incident reporting
procedures.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing use of any NEW of sonobuoys and 0.1-5 lb
(0.05-2.3 kg) NEW for other types of sub-surface explosives used in
research applications). The wait period for this activity is 30 minutes
for activities conducted from vessels and for activities conducted by
aircraft that are not fuel constrained and 10 minutes for activities
involving aircraft that are fuel constrained (e.g., rotary-wing
aircraft, fighter aircraft).
(xii) Explosive torpedoes. For explosive torpedoes:
(A) Mitigation zones and requirements. During the use of explosive
torpedoes of any NEW, the following mitigation zone requirements apply:
(1) Action Proponent personnel must cease use of explosive
torpedoes of any NEW if a marine mammal is sighted within 2,100 yd
(1,920.2 m) of the intended impact location.
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout in an aircraft.
(2) Conduct passive acoustic monitoring for marine mammals; use
information from detections to assist visual observations.
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals, floating vegetation, and jellyfish aggregations
immediately prior to the initial start of detonations (e.g., during
target deployment).
(2) Action Proponent personnel must observe the mitigation zone for
marine mammals and jellyfish aggregations during torpedo launches. If a
marine mammal is visibly injured or killed as a result of detonation,
use of explosives in the event must be suspended immediately.
(3) After the event, when practical, Action Proponent personnel
must observe the detonation vicinity for injured or dead marine
mammals. If any injured or dead marine mammals are observed, Action
Proponent personnel must follow established incident reporting
procedures.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing use of explosive torpedoes of any NEW).
The wait period for this activity is 30 minutes for activities
conducted from vessels and for activities conducted by aircraft that
are not fuel constrained and 10 minutes for activities involving
aircraft that are fuel constrained (e.g., rotary-wing aircraft, fighter
aircraft).
(xiii) Ship shock trials. For ship shock trials:
(A) Mitigation zones and requirements. During ship shock trials
using any NEW, the following mitigation zone requirements apply:
(1) Action Proponent personnel must cease ship shock trials of any
NEW if a marine mammal is sighted within 3.5 nmi (6.5 km) of the target
ship hull (cease fire).
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) On the day of the event, 10 observers (Lookouts and third-party
observers combined), spread between aircraft or multiple vessels as
specified in the event-specific mitigation plan.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must develop a detailed, event-
specific monitoring and mitigation plan in the year prior to the event
and provide it to NMFS for review.
(2) Beginning at first light on days of detonation until the moment
of detonation (as allowed by safety measures), Action Proponent
personnel must observe the mitigation zone for marine mammals, floating
vegetation, jellyfish aggregations, large schools of fish, and flocks
of seabirds.
(3) If any injured or dead marine mammals are observed after an
individual detonation, Action Proponent personnel must follow
established incident reporting procedures and halt any remaining
detonations until Action Proponent personnel consults with NMFS and
review or adapt the event-specific mitigation plan, if necessary.
(4) During the 2 days following the event (minimum) and up to 7
days following the event (maximum), and as specified in the event-
specific mitigation plan, Action Proponent personnel must observe the
detonation vicinity for injured or dead marine mammals.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing ship shock trials). The wait period for
this activity is 30 minutes.
[[Page 50714]]
(xiv) Sinking exercises. For Sinking Exercises (SINKEX):
(A) Mitigation zones and requirements. During SINKEX using any NEW,
the following mitigation zone requirements apply:
(1) Action Proponent personnel must cease SINKEX of any NEW if a
marine mammal is sighted within 2.5 nmi (4.6 km) of the target ship
hull (cease fire).
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) Two Lookouts, one on a vessel and one in an aircraft.
(2) Conduct passive acoustic monitoring for marine mammals; use
information from detections to assist visual observations.
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) During aerial observations for 90 minutes prior to the initial
start of weapon firing, Action Proponent personnel must observe the
mitigation zone for marine mammals, floating vegetation, and jellyfish
aggregations.
(2) From the vessel during weapon firing, and from the aircraft and
vessel immediately after planned or unplanned breaks in weapon firing
of more than 2 hours, Action Proponent personnel must observe the
mitigation zone for marine mammals. If a marine mammal is visibly
injured or killed as a result of detonation, use of explosives in the
event must be suspended immediately.
(3) Action Proponent personnel must observe the detonation vicinity
for injured or dead marine mammals for 2 hours after sinking the vessel
or until sunset, whichever comes first. If any injured or dead marine
mammals are observed, Action Proponent personnel must follow
established incident reporting procedures.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing SINKEX). The wait period for this
activity is 30 minutes.
(xv) Non-explosive aerial-deployed mines and bombs. For non-
explosive aerial-deployed mines and bombs:
(A) Mitigation zones and requirements. During the use of non-
explosive aerial-deployed mines and non-explosive bombs, the following
mitigation zone requirements apply:
(1) Action Proponent personnel must cease use of non-explosive
aerial-deployed mines and non-explosive bombs if a marine mammal is
sighted within 1,000 yd (914.4 m) of the intended target (cease fire).
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout in an aircraft.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals and floating vegetation immediately prior to the initial
start of mine or bomb delivery (e.g., when arriving on station).
(2) Action Proponent personnel must observe the mitigation zone for
marine mammals during mine or bomb delivery.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing use of non-explosive aerial-deployed
mines and non-explosive bombs). The wait period for this activity is 10
minutes.
(xvi) Non-explosive gunnery. For non-explosive gunnery:
(A) Mitigation zones and requirements. During the use of non-
explosive surface-to-surface large-caliber ordnance, non-explosive
surface-to-surface and air-to-surface medium-caliber ordnance, and non-
explosive surface-to-surface and air-to-surface small-caliber ordnance,
the following mitigation zone requirements apply:
(1) Action Proponent personnel must cease non-explosive surface-to-
surface large-caliber ordnance, non-explosive surface-to-surface and
air-to-surface medium-caliber ordnance, and non-explosive surface-to-
surface and air-to-surface small-caliber ordnance use if a marine
mammal is sighted within 200 yd (182.9 m) of the intended impact
location (cease fire).
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout on a vessel or in an aircraft.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals and floating vegetation immediately prior to the start
of gun firing (e.g., while maneuvering on station).
(2) Action Proponent personnel must observe the mitigation zone for
marine mammals during gunnery firing.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing use of non-explosive surface-to-surface
large-caliber ordnance, non-explosive surface-to-surface and air-to-
surface medium-caliber ordnance, and non-explosive surface-to-surface
and air-to-surface small-caliber ordnance). The wait period for this
activity is 30 minutes for activities conducted from vessels and for
activities conducted by aircraft that are not fuel constrained and 10
minutes for activities involving aircraft that are fuel constrained
(e.g., rotary-wing aircraft, fighter aircraft).
(xvii) Non-explosive missiles and rockets. For non-explosive
missiles and rockets:
(A) Mitigation zones and requirements. During the use of non-
explosive missiles and rockets (air-to-surface), the following
mitigation zone requirements apply:
(1) Action Proponent personnel must cease use of non-explosive
missile and rocket (air-to-surface) if a marine mammal is sighted
within 900 yd (823 m) of the intended impact location.
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout in an aircraft.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals and floating vegetation immediately prior to the start
of missile or rocket delivery (e.g., during a fly-over of the
mitigation zone).
(2) Action Proponent personnel must observe the mitigation zone for
marine mammals during missile or rocket delivery.
(D) Commencement or recommencement conditions. Action Proponent
personnel must ensure one of the commencement or recommencement
conditions in paragraph (a)(1)(xxi) of this section is met prior to the
initial start of the activity (by delaying the start) or during the
activity (by not recommencing use of non-explosive missiles and rockets
(air-to-surface)).
[[Page 50715]]
The wait period for this activity is 30 minutes for activities
conducted from vessels and for activities conducted by aircraft that
are not fuel constrained and 10 minutes for activities involving
aircraft that are fuel constrained (e.g., rotary-wing aircraft, fighter
aircraft).
(xviii) Manned surface vessels. For manned surface vessels:
(A) Mitigation zones and requirements. During the use of manned
surface vessels, including surfaced submarines, the following
mitigation zone requirements apply:
(1) Underway manned surface vessels must maneuver themselves (which
may include reducing speed) to maintain the following distances as
mission and circumstances allow:
(i) 500 yd (457.2 m) from whales.
(ii) 200 yd (182.9 m) from other marine mammals.
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One or more Lookouts on manned underway surface vessels in
accordance with the most recent navigation safety instruction.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals immediately prior to manned surface vessels getting
underway and while underway.
(2) [Reserved]
(xix) Unmanned vehicles. For unmanned vehicles:
(A) Mitigation zones and requirements. During the use of unmanned
surface vehicles and unmanned underwater vehicles already being
escorted (and operated under positive control) by a manned surface
support vessel, the following mitigation zone requirements apply:
(1) A surface support vessel that is already participating in the
event, and has positive control over the unmanned vehicle, must
maneuver the unmanned vehicle (which may include reducing its speed) to
ensure it maintains the following distances as mission and
circumstances allow:
(i) 500 yd (457.2 m) from whales.
(ii) 200 yd (182.9 m) from other marine mammals.
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout on a surface support vessel that is already
participating in the event and has positive control over the unmanned
vehicle.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals immediately prior to unmanned vehicles getting underway
and while underway.
(2) [Reserved]
(xx) Towed in-water devices. For towed in-water devices:
(A) Mitigation zones and requirements. During the use of in-water
devices towed by an aircraft, a manned surface vessel, or an unmanned
surface vehicle or unmanned underwater vehicle already being escorted
(and operated under positive control) by a manned surface vessel, the
following mitigation zone requirements apply:
(1) Manned towing platforms, or surface support vessels already
participating in the event that have positive control over an unmanned
vehicle that is towing an in-water device, must maneuver itself or the
unmanned vehicle (which may include reducing speed) to ensure towed in-
water devices maintain the following distances as mission and
circumstances allow:
(i) 250 yd (228.6 m) from marine mammals.
(ii) [Reserved]
(2) [Reserved]
(B) Lookout requirements. The following Lookout requirements apply:
(1) One Lookout on the manned towing vessel or aircraft, or on a
surface support vessel that is already participating in the event and
has positive control over an unmanned vehicle that is towing an in-
water device.
(2) [Reserved]
(C) Mitigation zone observation. Action Proponent personnel must
observe the mitigation zones in accordance with the following:
(1) Action Proponent personnel must observe the mitigation zone for
marine mammals immediately prior to and while in-water devices are
being towed.
(2) [Reserved]
(xxi) Commencement or recommencement conditions. Action Proponents
must not commence or recommence an activity after a marine mammal is
observed within a relevant mitigation zone until one of the following
conditions has been met:
(A) Observed exiting. A Lookout observes the marine mammal exiting
the mitigation zone;
(B) Concluded to have exited. A Lookout concludes that the marine
mammal has exited the mitigation zone based on its observed course,
speed, and movement relative to the mitigation zone;
(C) Clear from additional sightings. A Lookout affirms the
mitigation zone has been clear from additional sightings for the
activity-specific wait period; or
(D) Stressor transit. For mobile events, the stressor has transited
a distance equal to double the mitigation zone size beyond the location
of the last sighting.
(xxii) Exceptions to activity-based mitigation for acoustic and
explosive stressors. Activity-based mitigation for acoustic and
explosive stressors will not apply to:
(A) Sources not operated under positive control (e.g., moored
oceanographic sources);
(B) Sources used for safety of navigation (e.g., fathometers);
(C) Sources used or deployed by aircraft operating at high
altitudes (e.g., bombs deployed from high altitude);
(D) Sources used, deployed, or towed by unmanned platforms except
when escort vessels are already participating in the event and have
positive control over the source;
(E) Sources used by submerged submarines (e.g., sonar);
(F) De minimis sources (e.g., those >200 kilohertz);
(G) Unattended sources, such as moored buoys used for acoustic and
oceanographic research; and
(H) Vessel-based, unmanned vehicle-based, or towed in-water sources
when marine mammals (e.g., dolphins) are determined to be intentionally
swimming at the bow or alongside or directly behind the vessel,
vehicle, or device (e.g., to bow-ride or wake-ride).
(I) Explosives deployed by aircraft operating at high altitudes
(i.e., altitudes at which marine mammals on the surface cannot be
distinguished);
(J) Explosives deployed by submerged submarines, except for
explosive torpedoes;
(K) Explosives deployed against aerial targets;
(L) Explosives during vessel-launched missile or rocket events;
(M) Explosives used at or below the de minimis threshold (<=0.1 lb
(0.05 kg) NEW);
(N) Explosives deployed by unmanned platforms except when escort
vessels are already participating in the event and have positive
control over the explosive;
(O) Non-explosive ordnance deployed by aircraft operating at high
altitudes (i.e., altitudes at which marine mammals on the surface
cannot be distinguished);
(P) Non-explosive ordnance deployed against aerial targets;
[[Page 50716]]
(Q) Non-explosive ordnance deployed during vessel-launched missile
or rocket events; and
(R) Non-explosive ordnance deployed by unmanned platforms except
when escort vessels are already participating in the event and have
positive control over ordnance deployment.
(xxiii) Exceptions to activity-based mitigation for physical
disturbance and strike stressors. Activity-based mitigation for
physical disturbance and strike stressors will not be implemented:
(A) By submerged submarines;
(B) By unmanned vehicles except when escort vessels are already
participating in the event and have positive control over the unmanned
vehicle movements;
(C) When marine mammals (e.g., dolphins) are determined to be
intentionally swimming at the bow, alongside the vessel or vehicle, or
directly behind the vessel or vehicle (e.g., to bow-ride or wake-ride);
(D) When pinnipeds are hauled out on man-made navigational
structures, port structures, and vessels; and
(E) When impractical based on mission requirements (e.g., during
certain aspects of amphibious exercises).
(2) Geographic mitigation areas. The Action Proponents must
implement the geographic mitigation requirements described in
paragraphs (a)(2)(i) through (ix) of this section.
(i) Ship shock trial mitigation area. Figure 1 to this paragraph
(a)(2) shows the location of the mitigation areas. Within the ship
shock trial mitigation areas, the following requirements apply:
(A) Jacksonville Operating Area. Navy personnel must not conduct
ship shock trials within the portion of the ship shock trial box that
overlaps the Jacksonville Operating Area from November 15 through April
15.
(B) Pre-event planning. Pre-event planning for ship shock trials
must include the selection of one primary and two secondary sites
(within one of the ship shock trial boxes) where marine mammal
abundance is expected to be the lowest during an event, with the
primary and secondary locations located more than 2 nmi (3.7 km) from
the western boundary of the Gulf Stream for events planned within the
portion of the ship shock trial box that overlaps the Jacksonville
Operating Area.
(C) Environmentally unsuitable site. If Action Proponent personnel
determine during pre-event visual observations that the primary site is
environmentally unsuitable (e.g., continuous observations of marine
mammals), personnel must evaluate the potential to move the event to
one of the secondary sites as described in the LOAs.
(ii) Major Training Exercise Planning Awareness Mitigation Areas.
Figure 1 to this paragraph (a)(2) shows the location of the mitigation
area. Within the major training exercise (MTE) planning awareness
mitigation areas, the following requirements apply:
(A) Northeast. Within Major Training Exercise Planning Awareness
Mitigation Areas located in the northeast (i.e., the combined areas
within the Gulf of Maine, over the continental shelves off Long Island,
Rhode Island, Massachusetts, and Maine), the Action Proponents must not
conduct any full or partial MTEs.
(B) Mid-Atlantic. Within Major Training Exercise Planning Awareness
Mitigation Areas located in the mid-Atlantic (i.e., the combined areas
off Maryland, Delaware, and North Carolina), the Action Proponents must
not conduct any full or partial MTEs to the maximum extent practical
and must not conduct more than four full or partial MTEs per year.
(C) Gulf of America. Within the combined MTE Planning Awareness
Mitigation Areas located in the Gulf of America, the Action Proponents
will not conduct any MTEs.
(iii) Northeast North Atlantic Right Whale Mitigation Area. Figure
1 to this paragraph (a)(2) shows the location of the mitigation area.
Within the Northeast North Atlantic Right Whale Mitigation Area, the
following requirements apply:
(A) Active sonar. The Action Proponents must minimize the use of
low-frequency active sonar, mid-frequency active sonar, and high-
frequency active sonar in the mitigation area to the maximum extent
practical.
(B) In-water explosives. The Action Proponents must not detonate
in-water explosives (including underwater explosives and explosives
deployed against surface targets) within the mitigation area.
(C) Explosive sonobuoys. The Action Proponents must not detonate
explosive sonobuoys within 3 nmi (5.6 km) of the mitigation area.
(D) Non-explosive bombs. The Action Proponents must not use non-
explosive bombs within the mitigation area.
(E) Non-explosive torpedoes. During non-explosive torpedoes events
within the mitigation area:
(1) The Action Proponents must conduct activities during daylight
hours in Beaufort sea state 3 or less.
(2) The Action Proponents must post two Lookouts in an aircraft
during dedicated aerial surveys, and one Lookout on the submarine
participating in the event (when surfaced), in addition to Lookouts
required as described in paragraph (a)(1)(xvii) of this section.
(i) Lookouts must begin conducting visual observations immediately
prior to the start of an event.
(ii) If floating vegetation or marine mammals are observed in the
event vicinity, the event must not commence until the vicinity is clear
or the event is relocated to an area where the vicinity is clear.
(iii) Lookouts must continue to conduct visual observations during
the event.
(iv) If marine mammals are observed in the vicinity, the event must
cease until one of the commencement or recommencement conditions in
paragraph (a)(1)(xxi) of this section is met.
(3) During transits and normal firing, surface ships must maintain
a speed of no more than 10 knots (kn; 18.5 kilometer/hour (km/hr));
during submarine target firing, surface ships must maintain speeds of
no more than 18 kn (33.3 km/hr); and during vessel target firing,
surface ship speeds may exceed 18 kn (33.3 km/hr) for brief periods of
time (e.g., 10-15 minutes).
(F) Vessel transits. For vessel transits within the mitigation
area:
(1) North Atlantic right whale sightings. The Action Proponents
must conduct a web query or email inquiry to the North Atlantic Right
Whale Sighting Advisory System or WhaleMap (https://whalemap.org/) to
obtain the latest North Atlantic right whale sightings data prior to
transiting the mitigation area.
(2) Sightings data to Lookouts. To the maximum extent practical,
the Action Proponents must provide Lookouts the sightings data prior to
standing watch. Lookouts must use that data to help inform visual
observations during vessel transits.
(3) Speed reductions. Surface ships must implement speed reductions
after observing a North Atlantic right whale, if transiting within 5
nmi (9.3 km) of a sighting reported to the North Atlantic Right Whale
Sighting Advisory System within the past week, and when transiting at
night or during periods of restricted visibility.
(iv) Gulf of Maine Marine Mammal Mitigation Area. Figure 1 to this
paragraph (a)(2) shows the location of the mitigation area. Within the
Gulf of Maine Marine Mammal Mitigation Area, the following requirements
apply:
(A) Surface ship hull-mounted mid-frequency active sonar. The
Action Proponents must not use more than 200 hours of surface ship
hull-mounted mid-
[[Page 50717]]
frequency active sonar annually within the mitigation area.
(B) [Reserved]
(v) Martha's Vineyard North Atlantic Right Whale Mitigation Area.
Figure 1 to this paragraph (a)(2) shows the location of the mitigation
area. Within the Martha's Vineyard North Atlantic Right Whale
Mitigation Area, the following requirements apply:
(A) Propulsion testing. The Action Proponents must avoid conducting
vessel propulsion testing events in the Martha's Vineyard North
Atlantic Right Whale Mitigation Area, to the maximum extent practical.
(B) [Reserved]
(vi) Jacksonville Operating Area North Atlantic Right Whale
Mitigation Area. Figure 1 to this paragraph (a)(2) shows the location
of the mitigation area. Within the Jacksonville Operating Area North
Atlantic Right Whale Mitigation Area, the following requirements apply:
(A) November 15 to April 15. From November 15 to April 15 within
the mitigation area, prior to vessel transits or military readiness
activities involving active sonar, in-water explosives (including
underwater explosives and explosives deployed against surface targets),
or non-explosive ordnance deployed against surface targets (including
aerial-deployed mines), the Action Proponents must initiate
communication with Fleet Area Control and Surveillance Facility,
Jacksonville to obtain Early Warning System data. The facility must
advise of all reported North Atlantic right whale sightings in the
vicinity of planned vessel transits and military readiness activities.
Sightings data must be used when planning event details (e.g., timing,
location, duration) to minimize impacts to North Atlantic right whale
to the maximum extent practical.
(B) Sightings data to Lookouts. To the maximum extent practical,
Action Proponent personnel must provide the sightings data to Lookouts
prior to standing watch to help inform visual observations.
(vii) Southeast North Atlantic Right Whale Mitigation Area. Figure
1 to this paragraph (a)(2) shows the location of the mitigation area.
Within the Southeast North Atlantic Right Whale Mitigation Area, the
following requirements apply:
(A) Helicopter dipping sonar and low-frequency or surface ship
hull-mounted mid-frequency active sonar during navigation training or
object detection. From November 15 to April 15 within the mitigation
area, to the maximum extent practical, the Action Proponents must
minimize use of helicopter dipping sonar (a mid-frequency active sonar
source) and low-frequency or surface ship hull-mounted mid-frequency
active sonar during navigation training or object detection.
(B) All other high-frequency, mid-frequency, or low-frequency
active sonars. From November 15 to April 15 within the mitigation area,
the Action Proponents must not use high-frequency active sonar; or low-
frequency or mid-frequency active sonar with the exception of the
sources listed in paragraph (a)(2)(vi)(A) of this section in accordance
with that paragraph.
(C) Explosives. From November 15 to April 15 within the mitigation
area, the Action Proponents must not detonate in-water explosives
(including underwater explosives and explosives deployed against
surface targets).
(D) Explosive sonobuoys. From November 15 to April 15, the Action
Proponents must not detonate explosive sonobuoys within 3 nmi (5.6 km)
of the mitigation area.
(E) Physical disturbance. From November 15 to April 15 within the
mitigation area, the Action Proponents must not deploy non-explosive
ordnance against surface targets (including aerial-deployed mines).
(F) Vessel strike. From November 15 to April 15 within the
mitigation area, surface ships must minimize north-south transits to
the maximum extent practical and must implement speed reductions to the
maximum extent practicable after they observe a North Atlantic right
whale, if they are within 5 nmi (9.3 km) of an Early Warning System
sighting reported within the past 12 hours, and at night and in
restricted visibility.
(G) Vessel propulsion testing. From November 15 to April 15 within
the mitigation area, the Action Proponents must not conduct vessel
propulsion testing.
(H) Acoustic, explosives, and physical disturbance and vessel
strike. From November 15 to April 15 within the mitigation area, prior
to vessel transits or military readiness activities involving active
sonar, in-water explosives (including underwater explosives and
explosives deployed against surface targets), or non-explosive ordnance
deployed against surface targets (including aerial-deployed mines), the
Action Proponents must initiate communication with Fleet Area Control
and Surveillance Facility, Jacksonville to obtain Early Warning System
sightings data. The facility must advise of all reported North Atlantic
right whale sightings in the vicinity of planned vessel transits and
military readiness activities. To the maximum extent practical, the
Action Proponents must provide Lookouts the sightings data prior to
standing watch to help inform visual observations.
(viii) Dynamic North Atlantic Right Whale Mitigation Area. The
mitigation area extent matches the boundary of the U.S. Exclusive
Economic Zone on the East Coast, which is the full extent of where
Dynamic Management Areas could potentially be established by NMFS year-
round. Within the Dynamic North Atlantic Right Whale Mitigation Areas,
the following requirements apply:
(A) North Atlantic Right Whale Dynamic Management Area
notifications. The Action Proponents must provide North Atlantic Right
Whale Dynamic Management Area information (e.g., location and dates) to
applicable assets transiting and training or testing in the vicinity of
the Dynamic Management Area.
(1) Alert assets. The information must alert assets (and their
Lookouts) to the possible presence of North Atlantic right whale in
their vicinity.
(2) Visual observations. Lookouts must use the information to help
inform visual observations during military readiness activities that
involve vessel movements, active sonar, in-water explosives (including
underwater explosives and explosives deployed against surface targets),
or non-explosive ordnance deployed against surface targets in the
mitigation area.
(B) PMAP reports. In Protective Measures Assessment Protocol (PMAP)
reports generated in the Dynamic North Atlantic Right Whale Mitigation
Area, Action Proponents must do the following:
(1) WhaleMap. Provide the WhaleMap web address (https://whalemap.org);
(2) Strike risk. Advise that risk of whale strike is increased
after observing a North Atlantic right whale (NARW); when operating
within 5 nmi (9.3 km) of a known NARW sighting reported within the past
24 hours; within a NMFS-designated Seasonal Management Area, Dynamic
Management Area, or Slow Zone; and when transiting at night or during
periods of restricted visibility; and
(3) Reinforce collision prevention. Reinforce the requirement of
the International Regulations for Preventing Collisions at Sea
(COLREGS) for vessels to proceed at a safe speed appropriate to the
prevailing circumstances and conditions, to avoid a collision with any
sighted object or disturbance, including any marine mammal (33 CFR part
83).
(C) Propulsion testing. Sightings data must be used when planning
propulsion testing event details (e.g., timing, location, duration) to
minimize impacts
[[Page 50718]]
to NARW to the maximum extent practical. During propulsion testing in
the mitigation area, to the maximum extent practical, Lookouts must be
provided recent https://whalemap.org sightings data to help inform
visual observations.
(ix) Rice's Whale Mitigation Area. Figure 1 to this paragraph
(a)(2) shows the location of the mitigation area. Within the Rice's
Whale Mitigation Area, the following requirements apply:
(A) Surface ship mid-frequency active sonar. The Action Proponents
must not use more than 200 hours of surface ship hull-mounted mid-
frequency active sonar annually within the mitigation area.
(B) Explosives. The Action Proponents must not detonate in-water
explosives (including underwater explosives and explosives deployed
against surface targets) within the mitigation area, except during mine
warfare activities.
(C) Explosive sonobuoys. The Action Proponents must not detonate
explosive sonobuoys within 3 nmi (5.6 km) of the mitigation area.
(D) Propulsion testing. The Action Proponents must avoid conducting
vessel propulsion testing events in the Rice's Whale Mitigation Area,
to the maximum extent practical.
(E) Awareness message. The Action Proponents must issue an annual
awareness message to Navy vessels that routinely train or test in the
vicinity of the Rice's whale proposed critical habitat, and Coast Guard
vessels that routinely train anywhere in the Gulf of America. The
message will advise that risk of whale strike is increased when
transiting through Rice's whale proposed critical habitat (i.e., within
the 100-400 m isobaths), particularly at night or during periods of
restricted visibility, and reinforce the requirement of the COLREGS for
ships to proceed at a safe speed appropriate to the prevailing
circumstances and conditions, to avoid a collision with any sighted
object or disturbance, including any marine mammal.
(x) National security requirement. Should national security require
the Action Proponents to exceed a requirement(s) in paragraphs
(a)(2)(i) through (ix) of this section, Action Proponent personnel must
provide NMFS with advance notification and include the information
(e.g., sonar hours, explosives usage, or restricted area use) in its
annual activity reports submitted to NMFS.
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[[Page 50719]]
Figure 1 to Paragraph (a)(2)--Geographic Mitigation Areas for Marine
Mammals in the AFTT Study Area
[GRAPHIC] [TIFF OMITTED] TR07NO25.133
[[Page 50720]]
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(3) Cetacean live stranding. In the event of a cetacean live
stranding (or near-shore atypical milling) event within the AFTT Study
Area or within 50 km (27 nmi) of the boundary of the AFTT Study Area,
where the NMFS Stranding Network is engaged in herding or other
interventions to return marine mammals to the water, NMFS Office of
Protected Resources will advise the Action Proponents of the need to
implement shutdown procedures for all active acoustic sources or
explosive devices within 50 km of the stranding. Following this initial
shutdown, NMFS will communicate with the Action Proponents to determine
whether circumstances support modification of the shutdown zone. The
Action Proponents may decline to implement all or part of the shutdown
if the holder of the LOA, or his/her designee, determines that it is
necessary for national security. Shutdown procedures for live stranding
or milling cetaceans include the following:
(i) Shutdown no longer needed. If at any time, the marine mammal(s)
die or are euthanized, or if herding/intervention efforts are stopped,
NMFS will immediately advise that the shutdown around the marine
mammals' location is no longer needed;
(ii) Shutdown procedures remain in effect. Otherwise, shutdown
procedures will remain in effect until NMFS determines and advises that
all live marine mammals involved have left the area (either of their
own volition or following an intervention); and
(iii) Further observations. If further observations of the marine
mammals indicate the potential for re-stranding, additional
coordination will be required to determine what measures are necessary
to minimize that likelihood (e.g., extending the shutdown or moving
operations farther away) and to implement those measures as
appropriate.
(4) North Atlantic right whale persistence. Within the first year
of effectiveness of the LOA(s), the Action Proponents shall work
collaboratively with the NMFS Endangered Species Act Interagency
Cooperation Division and the NMFS Permits and Conservation Division to:
(1) Analyze and discuss the application of new information from the
NMFS North Atlantic Right Whale Persistence Modelling Efforts toward
AFTT mitigation measures;
(2) Evaluate the practicability and conservation benefits of newly
proposed mitigation measure and/or changes to existing measures based
on information from the model; and
(3) Implement any new mitigation measures or changes to existing
measures that meet the Action Proponents' Practicability Criteria and
Sufficiently Beneficial requirements.
(b) [Reserved]
Sec. 218.85 Requirements for monitoring and reporting.
The Action Proponents must implement the following monitoring and
reporting requirements when conducting the specified activities:
(a) Notification of take. If the Action Proponent reasonably
believes that the specified activity identified in Sec. 218.80
resulted in the mortality or serious injury of any marine mammals, or
in any Level A harassment or Level B harassment of marine mammals not
identified in this subpart, then the Action Proponent shall notify NMFS
immediately or as soon as operational security considerations allow.
(b) Monitoring and reporting under the LOAs. The Action Proponents
must conduct all monitoring and reporting required under the LOAs.
(c) Notification of injured, live stranded, or dead marine mammals.
Action Proponent personnel must abide by 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/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
(d) Annual AFTT Study Area marine species monitoring report. The
Navy, on behalf of the Action Proponents, must submit an annual AFTT
Study Area marine species monitoring report describing the
implementation and results from the previous calendar year. Data
collection methods will be standardized across range complexes and the
AFTT Study Area to allow for comparison in different geographic
locations. The draft report must be submitted to the Director, Office
of Protected Resources, NMFS, annually. NMFS will submit comments or
questions on the report, if any, within 3 months of receipt. The report
will be considered final after the Action Proponents have addressed
NMFS' comments, or 3 months after submittal of the draft if NMFS does
not provide comments on the draft report. The report must describe
progress of knowledge made with respect to intermediate scientific
objectives within the AFTT Study Area associated with the Integrated
Comprehensive Monitoring Program. Similar study questions must be
treated together so that progress on each topic can be summarized
across all Navy ranges. The report need not include analyses and
content that do not provide direct assessment of cumulative progress on
the monitoring plan study questions.
(e) Quick look reports. In the event that the sound levels analyzed
in the preambles of the Marine Mammal Protection Act (MMPA) proposed
rule (90 FR 19858, May 9, 2025) and final rule (90 FR [INSERT FEDERAL
REGISTER PAGE NUMBER], November 7, 2025) were exceeded within a given
reporting year, the Action Proponents must submit a preliminary
report(s) detailing the exceedance within 21 days after the anniversary
date of issuance of the LOAs.
(f) Annual AFTT training and testing reports. Regardless of whether
analyzed sound levels were exceeded, the Navy must submit a detailed
report (AFTT Annual Training Exercise Report and Testing Activity
Report) and the Coast Guard must submit a detailed report (AFTT Annual
Training Exercise Report) to the Director, Office of Protected
Resources, NMFS, annually. NMFS will submit comments or questions on
the reports, if any, within 1 month of receipt. The reports will be
considered final after the Action Proponents have addressed NMFS'
comments, or 1 month after submittal of the drafts if NMFS does not
provide comments on the draft reports. The annual reports must contain
a summary of all sound sources used (total hours or quantity (per the
LOAs) of each bin of sonar or other non-impulsive source; total annual
number of each type of explosive exercises; and total annual expended/
detonated rounds (missiles, bombs, sonobuoys, etc.) for each explosive
bin). The annual reports must also contain cumulative sonar and
explosive use quantity from previous years' reports through the current
year. Additionally, if there were any changes to the sound source
amount analyzed in the reporting year, or cumulatively, the reports
would 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 2025 AFTT Supplemental Environmental Impact Statement/Overseas
Environmental Impact Statement (https://www.nepa.navy.mil/aftteis/) and
the analysis in the MMPA final rule (90 FR [INSERT FEDERAL REGISTER
PAGE NUMBER], November 7, 2025). The annual reports must also include
the details regarding specific requirements associated with the
[[Page 50721]]
mitigation areas listed in paragraph (f)(4) of this section. The
analysis in the detailed report must be based on the accumulation of
data from the current year's report and data collected from previous
annual reports. The final annual/close-out reports at the conclusion of
the authorization period (year 7) will also serve as the comprehensive
close-out reports and provide the annual totals for each sound source
bin with a comparison to the annual amount analyzed and the 7-year
total for each sound source bin with a comparison to the 7-year amount
analyzed. The AFTT Annual Training and Testing Reports must include the
specific information described in the LOAs.
(1) MTEs. This section of the report must contain the following
information for MTEs completed that year in the AFTT Study Area.
(i) Exercise information (for each MTE). For exercise information
(for each MTE):
(A) Exercise designator.
(B) Date that exercise began and ended.
(C) Location.
(D) Number and types of active sonar sources used in the exercise.
(E) Number and types of passive acoustic sources used in exercise.
(F) Number and types of vessels, aircraft, and other platforms
participating in each exercise.
(G) Total hours of all active sonar source operation.
(H) Total hours of each active sonar source bin.
(I) Wave height (high, low, and average) during exercise.
(ii) Individual marine mammal sighting information for each
sighting in each exercise where mitigation was implemented. For
individual marine mammal sighting information for each sighting in each
exercise where mitigation was implemented:
(A) Date, time, and location of sighting.
(B) Species (if not possible, indication of whale/dolphin/
pinniped).
(C) Number of individuals.
(D) Initial detection sensor (e.g., passive sonar, Lookout).
(E) Indication of specific type of platform observation was made
from (including, for example, what type of surface vessel or testing
platform).
(F) Length of time observers maintained visual contact with marine
mammal.
(G) Sea state.
(H) Visibility.
(I) Sound source in use at the time of sighting.
(J) Indication of whether marine mammal was less than 200 yd (182.9
m), 200 to 500 yd (182.9 to 457.2 m), 500 to 1,000 yd (457.2 m to 914.4
m), 1,000 to 2,000 yd (914.4 m to 1,828.8 m), or greater than 2,000 yd
(1,828.8 m) from sonar source.
(K) Whether operation of sonar sensor was delayed, or sonar was
powered or shut down, and the length of the delay.
(L) If source in use was hull-mounted, true bearing of marine
mammal from the vessel, true direction of vessel's travel, and
estimation of marine mammal's motion relative to vessel (opening,
closing, parallel).
(M) Lookouts must report the observed behavior of the marine
mammal(s) in plain language and without trying to categorize in any way
(such as marine mammal closing to bow ride, paralleling course/speed,
floating on surface and not swimming, etc.) and if any calves were
present.
(iii) An evaluation (based on data gathered during all of the MTEs)
of the effectiveness of mitigation measures designed to minimize the
received level to which marine mammals may be exposed. For an
evaluation (based on data gathered during all of the MTEs) of the
effectiveness of mitigation measures designed to minimize the received
level to which marine mammals may be exposed:
(A) This evaluation must identify the specific observations that
support any conclusions the Navy reaches about the effectiveness of the
mitigation.
(B) [Reserved]
(2) Sinking exercises. This section of the report must include the
following information for each SINKEX completed that year in the AFTT
Study Area:
(i) Exercise information. For exercise information:
(A) Location.
(B) Date and time exercise began and ended.
(C) Total hours of observation by Lookouts before, during, and
after exercise.
(D) Total number and types of explosive source bins detonated.
(E) Number and types of passive acoustic sources used in exercise.
(F) Total hours of passive acoustic search time.
(G) Number and types of vessels, aircraft, and other platforms
participating in exercise.
(H) Wave height in feet (high, low, and average) during exercise.
(I) 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 Action Proponent
Lookouts) information for each sighting where mitigation was
implemented. For individual marine mammal observation (by Action
Proponent Lookouts) information for each sighting where mitigation was
implemented:
(A) Date/time/location of sighting.
(B) Species (if not possible, indicate whale, dolphin, or
pinniped).
(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 (182.9 m), 200 to 500 yd
(182.9 to 457.2 m), 500 to 1,000 yd (457.2 to 914.4 m), 1,000 to 2,000
yd (914.4 to 1,828.8 m), or greater than 2,000 yd (1,828.8 m).
(J) Lookouts must report the observed behavior of the marine
mammal(s) in plain language and without trying to categorize in any way
(such as marine mammal 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.
(3) Summary of sources used. This section of the report must
include the following information summarized from the analyzed sound
sources used in all training and testing events:
(i) Totals for sonar or other acoustic source bins. Total annual
hours or quantity (per the LOA) of each bin of sonar or other acoustic
sources (e.g., pile driving and air gun activities); and
(ii) Total for explosive bins. Total annual expended/detonated
ordnance (missiles, bombs, sonobuoys, etc.) for each explosive bin.
(4) Special reporting for geographic mitigation areas. This section
of the report must contain the following information for activities
conducted in geographic mitigation areas in the AFTT Study Area:
(i) Northeast North Atlantic Right Whale Mitigation Area. The
Action Proponents must report the total annual hours and counts of
active sonar and in-water explosives (including underwater
[[Page 50722]]
explosives and explosives deployed against surface targets) used in the
mitigation area.
(ii) Gulf of Maine Marine Mammal Mitigation Area. The Action
Proponents must report the total annual hours and counts of active
sonar and in-water explosives (including underwater explosives and
explosives deployed against surface targets) used in the mitigation
area.
(iii) Southeast North Atlantic Right Whale Mitigation Area. The
Action Proponents must report the total annual hours and counts of
active sonar and in-water explosives (including underwater explosives
and explosives deployed against surface targets) used in the mitigation
area from November 15 to April 15.
(iv) Southeast North Atlantic Right Whale Special Reporting
Mitigation Area. The Action Proponents must report the total annual
hours and counts of active sonar and in-water explosives (including
underwater explosives and explosives deployed against surface targets)
used within the mitigation area from November 15 to April 15.
(v) Rice's Whale Mitigation Area. The Action Proponents must report
the total annual hours and counts of active sonar and in-water
explosives (including underwater explosives and explosives deployed
against surface targets) used in the mitigation area.
(vi) National security requirement. If an Action Proponent(s)
evokes the national security requirement described in Sec.
218.84(a)(2)(ix), the Action Proponent personnel must include
information about the event in its Annual AFTT Training and Testing
Report.
(5) Foreign military sonar and explosives. Navy personnel must
confirm that foreign military use of sonar and explosives, when such
militaries are participating in a U.S. Navy-led exercise or event,
combined with the Action Proponents' use of sonar and explosives, would
not cause exceedance of the analyzed levels within each NAEMO modeled
sonar and explosive bin used for estimating predicted impacts.
(g) MTE sonar exercise notification. The Action Proponents must
submit to NMFS (contact as specified in the LOAs) an electronic report
within 15 calendar days after the completion of any MTE indicating:
(1) Location. Location of the exercise;
(2) Dates. Beginning and end dates of the exercise; and
(3) Type. Type of exercise.
Sec. 218.86 Letters of Authorization.
(a) To incidentally take marine mammals pursuant to this subpart,
the Action Proponents must apply for and obtain LOAs.
(b) An LOA, unless suspended or revoked, may be effective for a
period of time not to exceed the expiration date of this subpart.
(c) In the event of projected changes to the activity or to
mitigation, monitoring, or reporting measures (excluding changes made
pursuant to the adaptive management provision of Sec. 218.87(c)(1))
required by an LOA, the Action Proponent must apply for and obtain a
modification of the LOA as described in Sec. 218.87.
(d) 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 and stocks of marine mammals and their
habitat; and
(4) Requirements for monitoring and reporting.
(e) Issuance of the LOA(s) must be based on a determination that
the level of taking is consistent with the findings made for the total
taking allowable under the regulations of this subpart.
(f) Notice of issuance or denial of the LOA(s) will be published in
the Federal Register within 30 days of a determination.
Sec. 218.87 Modifications of Letters of Authorization.
(a) An LOA issued under Sec. Sec. 216.106 of this chapter and
218.86 for the activity identified in Sec. 218.80(c) shall be
modified, upon request by an Action Proponent(s), provided that:
(1) The 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 LOAs under this subpart were
implemented.
(b) For LOA modification requests by the applicants 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), the LOA should be
modified provided that:
(1) NMFS determines that the change(s) to the activity or the
mitigation, monitoring, or reporting do not change the findings made
for this subpart and do not result in more than a minor change in the
total estimated number of takes (or distribution by species or stock or
years); and
(2) NMFS may publish a notice of proposed modified 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
218.86 for the activities identified in Sec. 218.80(c) may be modified
by NMFS Office of Protected Resources under the following
circumstances:
(1) After consulting with the Action Proponents regarding the
practicability of the modifications, through adaptive management, NMFS
may modify (including remove, revise, or add to) 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 measures set forth in this subpart.
(i) Possible sources of data that could contribute to the decision
to modify the mitigation, monitoring, or reporting measures in an LOA
include, but are not limited to:
(A) Results from the Action Proponents' monitoring report and
annual exercise reports from the previous year(s);
(B) Results from other marine mammal and/or sound research or
studies; or
(C) Any information that reveals marine mammals may have been taken
in a manner, extent, or number not authorized by this subpart or
subsequent LOAs.
(ii) If, through adaptive management, the modifications to the
mitigation, monitoring, or reporting measures are substantial, NMFS
shall publish a notice of proposed LOA(s) in the Federal Register and
solicit public comment.
(2) If the NMFS Office of Protected Resources determines that an
emergency exists that poses a significant risk to the well-being of the
species or stocks of marine mammals specified in LOAs issued pursuant
to Sec. Sec. 216.106 of this chapter and 218.86, a LOA may be modified
without prior notice or opportunity for public comment. Notice would be
published in the Federal Register within 30 days of the action.
Sec. Sec. 218.88-218.89 [Reserved]
[FR Doc. 2025-19806 Filed 11-6-25; 8:45 am]
BILLING CODE 3510-22-P