Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to U.S. Marine Corps Training Exercises at Cherry Point Range Complex, North Carolina, 14886-14901 [2020-05233]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 85, Number 51 (Monday, March 16, 2020)]
[Notices]
[Pages 14886-14901]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-05233]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XR102]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to U.S. Marine Corps Training 
Exercises at Cherry Point Range Complex, North Carolina

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from the U.S. Marine Corps (USMC) 
for authorization to take marine mammals incidental to training 
exercises at Marine Corps Air Station (MCAS) Cherry Point Range 
Complex, North Carolina. Pursuant to the Marine Mammal Protection Act 
(MMPA), NMFS is requesting comments on its proposal to issue an 
incidental harassment authorization (IHA) to incidentally take marine 
mammals during the specified activities. NMFS is also requesting 
comments on a possible one-year renewal that could be issued under 
certain circumstances and if all requirements are met, as described in 
Request for Public Comments at the end of this notice. NMFS will 
consider public comments prior to making any final decision on the 
issuance of the requested MMPA authorizations and agency responses will 
be summarized in the final notice of our decision. The USMC's 
activities are considered military readiness activities pursuant to the 
MMPA, as amended by the National Defense Authorization Act for Fiscal 
Year 2004 (NDAA).

[[Page 14887]]


DATES: Comments and information must be received no later than April 
15, 2020.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. All comments 
received are a part of the public record and will generally be posted 
online at www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities without 
change. All personal identifying information (e.g., name, address) 
voluntarily submitted by the commenter may be publicly accessible. Do 
not submit confidential business information or otherwise sensitive or 
protected information.

FOR FURTHER INFORMATION CONTACT: Ben Laws, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: 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 above.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.
    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 and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth.
    The NDAA (Pub. L. 108-136) removed the ``small numbers'' and 
``specified geographical region'' limitations indicated above and 
amended the definition of ``harassment'' as it applies to a ``military 
readiness activity.'' The activity for which incidental take of marine 
mammals is being requested addressed here qualifies as a military 
readiness activity. The definitions of all applicable MMPA statutory 
terms cited above are included in the relevant sections below.

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, we 
must review our proposed action (i.e., the issuance of an incidental 
harassment authorization) with respect to potential impacts on the 
human environment. In 2015, NMFS developed an Environmental Assessment 
(EA) evaluating the impacts of authorizing take of marine mammals 
incidental to the USMC's training activities at MCAS Cherry Point. 
Following review of this analysis, NMFS determined that the activity 
would not have a significant effect on the quality of the human 
environment and issued a Finding of No Significant Impact (FONSI).
    NMFS has preliminarily determined that there are no substantive 
changes to the evaluated action or new environmental impacts and, 
therefore, the previous NEPA analysis remains valid. The 2015 EA and 
FONSI are posted online at www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. We will review all comments submitted in response to this 
notice prior to concluding our NEPA process or making a final decision 
on the IHA request.

Summary of Request

    On September 28, 2019, NMFS received a request from the USMC for an 
IHA to take marine mammals incidental to training exercises conducted 
at MCAS Cherry Point Range Complex in North Carolina. Following NMFS' 
review of the request, USMC submitted a revised application that was 
deemed adequate and complete on January 22, 2020. The USMC's request is 
for take of bottlenose dolphin (Tursiops truncatus) by Level A and 
Level B harassment. Neither the USMC nor NMFS expect serious injury or 
mortality to result from this activity. Therefore, an IHA is 
appropriate. The proposed IHA would be effective for a period of one 
year from the date of issuance.
    NMFS previously issued incidental take authorizations to the USMC 
for the same activities, including three IHAs associated with training 
activities from 2010-2014 (75 FR 72807, November 26, 2010; 77 FR 87, 
January 3, 2012; and 78 FR 42042, July 15, 2013) and incidental take 
regulations and a subsequent Letter of Authorization issued in 
association with training activities conducted from 2015-2020 (80 FR 
13264, March 13, 2015). The USMC complied with all the requirements 
(e.g., mitigation, monitoring, and reporting) of the previous 
incidental take authorizations and information regarding their 
monitoring results may be found in the Estimated Take section.

Description of Proposed Activity

Overview

    The USMC conducts training to meet its statutory responsibility to 
organize, train, equip, and maintain combat-ready forces. The training 
activities include air-to-surface and surface-to-surface weapons 
delivery, weapons firing, and water-based training occurring at the 
Brant Island Bombing Target (BT-9) and Piney Island Bombing Range (BT-
11) located within the MCAS Cherry Point Range Complex in Pamlico 
Sound, North Carolina. The USMC training activities are military 
readiness activities under the MMPA as defined by the National Defense 
Authorization Act for Fiscal Year 2004 (NDAA; Public Law 108-136).

Dates and Duration

    The proposed activities could occur at any time during the one year 
period of effectiveness of the proposed IHA. Activities are typically 
conducted during daylight hours but may occur at night.

[[Page 14888]]

Specific Geographic Region

    The USMC's BT-9 and BT-11 bombing targets (See Figures 1-1 and 2-1 
in the USMC application) are located in inshore waters of Pamlico 
Sound, North Carolina in the vicinity of the convergence of the Neuse 
River and Pamlico River, North Carolina.
    The BT-9 area is a water-based bombing target and mining exercise 
area located approximately 52 kilometers (km) (32.3 miles (mi)) 
northeast of MCAS Cherry Point. The U.S. Army Corps of Engineers, 
Wilmington District has defined a danger zone (prohibited area) by a 6 
statute-mile (sm) diameter boundary around BT-9 (33 CFR 334.420). This 
restriction prohibits non-military vessels within the designated area. 
The BT-9 target area ranges in depth from 1.2 to 6.1 meters (m) (3.9 to 
20 feet (ft)), with the shallow areas concentrated along the Brant 
Island Shoal. The target itself consists of three ship hulls grounded 
on Brant Island Shoals, located approximately 4.8 km (3.0 mi) southeast 
of Goose Creek Island. The BT-9 target and associated danger zone is 
entirely in/over water.
    The BT-11 area encompasses a total of 50.6 square kilometers 
(km\2\) (19.5 square miles (mi\2\)) on Piney Island located in Carteret 
County, NC. The target prohibited area, at a radius of 1.8 sm, is 
roughly centered on Rattan Bay and includes approximately 9.3 km\2\ 
(3.6 mi\2\) of water and water depths range from 0.3 m (1.0 ft) along 
the shoreline to 3.1 m (10.1 ft) in the center of Rattan Bay. Water 
depths in the center of Rattan Bay range from approximately 2.4 to 3 m 
(8 to 10 ft) with bottom depths ranging from 0.3 to 1.5 m (1 to 5 ft) 
adjacent to the shoreline of Piney Island. The in-water stationary 
targets of BT-11 consist of a barge and patrol boat located in roughly 
the center of Rattan Bay. The USMC also use a second danger zone, also 
roughly centered on Rattan Bay, on an intermittent basis for strafing 
at water- and land-based targets, with an inner radius of 1.8 sm and 
outer radius of 2.5 sm. Note that at BT-11, only a portion of the 
associated composite danger zone is over water (36 percent). Therefore, 
the USMC assumes that only 36 percent of expended ordnance would 
potentially strike water.
    The USMC conducts all inert and live-fire exercises at BT-9 and BT-
11 so that all ammunition and other ordnances strike and/or fall on the 
land or water-based targets or within the existing danger zones or 
water restricted areas. Military forces close danger zones to the 
public on an intermittent or full-time basis for hazardous operations 
such as target practice and ordnance firing. They also prohibit or 
limit public access to water restricted areas to provide security for 
government property and/or to protect the public from the risks of 
injury or damage that could occur from the government's use of that 
area (33 CFR 334.2). Surface danger zones are designated areas of 
rocket firing, target practice, or other hazardous operations (33 CFR 
334.420). The surface danger zone (prohibited area) for BT-9 is a 4.8 
km (3.0 mi) radius centered on the south side of Brant Island Shoal. 
The surface danger zone for BT-11 is a 2.9 km (1.8 mi) radius centered 
on a barge target in Rattan Bay.

Detailed Description of Specific Activity

    The following sections describe the training activities that have 
the potential to affect marine mammals present within the BT-9 and BT-
11 bombing targets. These activities fall into two categories based on 
the ordnance delivery method: (1) Surface-to-surface gunnery exercises; 
and (2) air-to-surface bombing exercises. Note that deployment of live 
ordnance is only permitted at BT-9; all munitions fired at BT-11 are 
inert.
Surface-to-Surface Exercises
    Gunnery exercises are the only category of surface-to-surface 
activity currently conducted within BT-9 or BT-11. BT-9 is the most 
common target used for gunnery exercises. Surface-to-surface gunnery 
firing exercises typically involve Special Boat Team personnel firing 
munitions from a machine gun and 40 mm grenade launchers at a water-
based target or throwing concussion grenades into the water (e.g., not 
at a specific target) from a small boat. The number and type of boats 
used depend on the unit using the boat and the particular training 
mission. These include: Small unit river craft, combat rubber raiding 
craft, rigid hull inflatable boats, and patrol craft. These boats may 
use inboard or outboard, diesel or gasoline engines with either 
propeller or water jet propulsion systems. Each boat would travel 
between 0 to 20 knots (kts) (0 to 23 miles per hour (mph)) with an 
average of two vessels to approach and engage the intended targets. The 
boats typically travel in linear paths and do not operate erratically.
    Boat sorties occur in all seasons and the number of sorties 
conducted at each range may vary from year to year based on training 
needs and worldwide operational tempo. The majority of boat sorties at 
BT-9 originate from MCAS Cherry Point's Navy boat docks, but they may 
also originate from the State Port in Morehead City, NC; Marine Corps 
Base Camp Lejeune; and U.S. Coast Guard Station Hobucken in Pamlico 
Sound. The majority of boat sorties at BT-11 originate from launch 
sites within the range complex.
    There is no specific schedule associated with the use of BT-9 or 
BT-11 by the small boat teams. However, the USMC schedules the 
exercises for 5-day blocks with exercises at various times throughout 
the year. Variables such as deployment status, range availability, and 
completion of crew-specific training requirements influence the 
exercise schedules.
    The direct-fire gunnery exercises (i.e., all targets are within the 
line of sight of the military personnel) at BT-9 would typically use 
7.62 millimeter (mm) or .50 caliber (cal) machine guns; 40 mm grenade 
machine guns; or G911 concussion hand grenades. The proposed exercises 
at BT-9 are usually live-fire exercises. At times USMC personnel would 
use blanks (inert ordnance) so that the boat crews could practice ship-
handling skills during training without being concerned with the safety 
requirements involved with live weapons.
Air-to-Surface Exercises
    Air-to-surface training exercises involve fixed-, rotary-, or tilt-
wing aircraft firing munitions at targets on the water's surface or on 
land (in the case of BT-11). There are four types of air-to-surface 
activities conducted within BT-9 and BT-11. They include: Mine laying, 
bombing, gunnery, or rocket exercises. The following sections provide 
more detail on each exercise type that would be conducted.
Mine Laying Exercises
    Mine laying exercises are simulations only, meaning that mine 
detonations would not occur during training. These exercises, regularly 
conducted at the BT-9 bombing target, involve the use of fixed-wing 
aircraft flying to the target area using either a low- or high-altitude 
tactical flight pattern. When the aircraft reaches the target area, the 
pilot deploys a series of inert mine shapes in an offensive or 
defensive pattern into the water. The aircraft would make multiple 
passes along a pre-determined flight azimuth dropping one or more of 
the inert shapes each time.
    The mine-laying exercises at BT-9 would include the use of MK-62, 
MK-63, MK-76, BDU-45, and BDU-48 inert training shapes. Each inert 
shape weighs 500, 1,000, 25, 500, and 10 pounds (lbs) (227, 454, 11, 
227, and 5 kg), respectively.

[[Page 14889]]

Bombing Exercises
    Pilots train to destroy or disable enemy ships or boats during 
bombing exercises. These exercises, conducted at BT-9 or BT-11, 
normally involve the use of two to four fixed-wing aircraft approaching 
the target area from an altitude of approximately 152 m (500 ft) up to 
4,572 m (15,000 ft). When the aircraft reach the target area, they 
establish a predetermined racetrack pattern relative to the target and 
deliver the bombs. Participating aircraft follow the same flight path 
during subsequent target ingress, ordnance delivery, target egress, and 
downwind pattern. This type of pattern is used to ensure that only one 
aircraft releases ordnance at any given time.
    The pilots deliver the bombs against targets at BT-9 or BT-11, day 
or night; the average time to complete this type of exercise is 
approximately one hour. There is no set level or pattern of amount of 
sorties conducted. There are no cluster munitions authorized for use 
during bombing exercises.
    The bombing exercises would typically use unguided MK-76 and BDU-45 
inert training bombs or precision-guided munitions consisting of laser-
guided bombs (inert) and laser-guided training rounds.
Gunnery Exercises
    During air-to-surface gunnery exercises with cannons, pilots train 
to destroy or disable enemy ships, boats, or floating/near-surface 
mines from aircraft with mounted cannons equal to or larger than 20 mm. 
The USMC would use either fixed-wing or rotary-wing, tilt-rotor, and 
other aircraft to conduct gunnery exercises at BT-9 or BT-11. During 
the exercise (i.e., strafing run), two aircraft would approach the 
target area from an altitude of approximately 914 m (3,000 ft) and 
within a distance of 1,219 m (4,000 ft) from the target, begin to fire 
a burst of approximately 30 rounds of munitions before reaching an 
altitude of 305 m (1,000 ft) to break off the attack. Each aircraft 
would reposition for another strafing run until each aircraft expends 
its exercise ordnance of approximately 250 rounds (approximately 8-12 
passes per aircraft per exercise). This type of gunnery exercise would 
typically use a 20 mm or 25 mm cannon. The USMC uses inert munitions 
for these exercises. The aircraft deliver the ordnance against targets 
at BT-9 or BT-11, day or night. The average time to complete this type 
of exercise is approximately 1 hour.
    During air-to-surface gunnery exercises with machine guns, pilots 
train to destroy or disable enemy ships, boats, or floating/near-
surface mines with aircraft using mounted machine guns. The USMC 
typically uses rotary-wing aircraft to conduct gunnery exercises at BT-
9 or BT-11. During the exercise an aircraft would fly around the target 
area at an altitude between 15 and 30 m (50 and 100 ft) in a 91 m (300 
ft) racetrack pattern around the water-based target. Each gunner would 
expend approximately 800 rounds of 7.62 mm ammunition or 200 rounds of 
.50 cal ammunition in each exercise. The aircraft deliver the ordnance 
against the bombing targets at BT-9 or BT-11, day or night. The average 
time to complete this type of exercise is approximately 1 hour.
Rocket Exercises
    Rocket exercises are similar to the bombing exercises. Fixed- and 
rotary-wing aircraft crews launch rockets at surface maritime targets, 
day and night, to train for destroying or disabling enemy ships or 
boats. These operations employ 2.75-inch and 5-inch (70- and 127-mm) 
rockets (4.8 and 15.0 lbs net explosive weight, respectively). 
Generally, personnel would deliver an average of approximately 14 
rockets per sortie. As with the bombing exercises, there is no set 
level or pattern of amount of sorties conducted.
Munitions and Estimated Expenditures
    There are several varieties of ordnance and net explosive weights 
(for live munition used at BT-9) can vary according to type. All 
practice bombs are inert but simulate the same ballistic properties of 
service type bombs. They are either solid cast metal bodies or thin 
sheet metal containers. Since practice bombs contain no explosive 
filler, a practice bomb signal cartridge (smoke) serves as a visual 
observation of weapon target impact. Please refer to Table 1-1 in 
USMC's application for a full list of all munitions authorized for use 
at BT-9 and BT-11.
    The estimated amount of ordnance to be annually expended at BT-9 
and BT-11 under the activity is 1,238,614 and 1,254,684, respectively 
(Tables 1 and 2). The amounts of ordnance expended at the BTs account 
for all uses of the targets, including use by other services. All 
ordnance expended at BT-11 would be inert. There are five types of 
explosive sources used at BT-9: 2.75-in Rocket High Explosives (HE), 5-
in Rocket HE, 30 mm HE, 40 mm HE, and G911 grenades. The estimated 
ordnance expenditure at BT-9 includes less than 2 percent high 
explosive rounds and less than 0.1 percent each of live rockets and 
grenades. The approximate quantities of ordnance listed in Tables 1 and 
2 represent conservative figures, meaning that the volume of each type 
of inert and explosive ordnance proposed is the largest number that 
personnel could expend but is not necessarily expected. As noted 
previously, only 36 percent of expended ordnance at BT-11 is assumed to 
potentially strike water.

 Table 1--Type of Ordnance, Net Explosive Weight, and Proposed Levels of
                       Annual Expenditures at BT-9
------------------------------------------------------------------------
                                                             Proposed
         Proposed ordnance          Net explosive weight     number of
                                       in pounds (lbs)        rounds
------------------------------------------------------------------------
Small arms excluding .50 cal (7.62  N/A, inert..........         525,610
 mm).
.50 cal...........................  N/A, inert..........         568,515
Large arms--live (30 mm)..........  0.1019..............           3,432
Large arms--live (40 mm)..........  0.1199..............          10,420
Large arms--inert.................  N/A.................         120,405
Rockets--live (2.75-inch).........  4.8.................             220
Rockets--live (5-inch)............  15.0................              68
Rockets--inert....................  N/A.................             844
Grenades--live (G911).............  0.5.................             144
Bombs--inert......................  N/A.................           4,460
Pyrotechnics--inert...............  N/A.................           2,500
------------------------------------------------------------------------


[[Page 14890]]


 Table 2--Type of Ordnance, Net Explosive Weight, and Proposed Levels of
                      Annual Expenditures at BT-11
------------------------------------------------------------------------
                                                             Proposed
         Proposed ordnance          Net explosive weight     number of
                                       in pounds (lbs)        rounds
------------------------------------------------------------------------
Small arms excluding .50 cal (7.62  N/A, inert..........       1,250,000
 mm).
.50 cal...........................  N/A, inert..........         425,000
Large arms--inert.................  N/A.................         240,334
Rockets--inert....................  N/A.................           6,250
Bombs and grenades--inert.........  N/A.................          22,114
Pyrotechnics--inert...............  N/A.................           8,912
------------------------------------------------------------------------

    Take of marine mammals is not anticipated to result from direct 
strike by inert ordnance or as a result of vessel strike during small 
boat maneuvers. The USMC has estimated that the probability of direct 
strike of a dolphin by inert ordnance during any given ordnance 
deployment is 2.61 x 10-7 or 9.4 x 10-8 at BT-9 
and BT-11, respectively. These estimated probabilities result in 
estimated numbers of ordnance strikes of <0.5 at both target areas and, 
therefore, in context of the required mitigation requirements, the 
USMC's conclusion is that no take is reasonably anticipated to occur as 
a result of direct strike from inert ordnance. Please see the USMC 
application for further detail on the analysis. The USMC has also 
determined that vessel strike is not a reasonably anticipated outcome 
of the specified activity, due to the limited number of small boat 
maneuvers and low concentrations of dolphins expected to be present. No 
incidents of direct strike from inert ordnance or of vessel strike have 
been recorded during prior years of activity monitoring. NMFS concurs 
with these determinations, and vessel maneuvers and inert ordnance are 
not discussed further in this document.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Summary of Previous Monitoring

    During monitoring conducted over the period 2015-2019, USMC 
expended an annual average amount of ordnance of 818,512 and 1,535,404 
at BT-9 and BT-11, respectively. During this period, no high explosive 
munitions were used. On 50 occasions, dolphins were observed by 
contracted range sweep aircraft along the pre-defined flight path of 
the range sweep. No marine mammals were observed during air-to-surface 
training activities (rotary-wing or fixed-wing aircraft), or by 
maintenance vessels. For additional detail, please see section 7 of the 
USMC's application.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected stocks of 
bottlenose dolphin. Additional information regarding population trends 
and threats may be found in NMFS's Stock Assessment Reports (SARs; 
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (www.fisheries.noaa.gov/find-species).
    Table 3 lists all species with expected potential for occurrence in 
the project area and summarizes information related to the population 
or stock, including regulatory status under the MMPA and ESA and 
potential biological removal (PBR), where known. PBR is defined by the 
MMPA as the maximum number of animals, not including natural 
mortalities, that may be removed from a marine mammal stock while 
allowing that stock to reach or maintain its optimum sustainable 
population (as described in NMFS's SARs). While no mortality or serious 
injury is anticipated or authorized here, PBR and annual serious injury 
and mortality from anthropogenic sources are included here as gross 
indicators of the status of the species and other threats. All managed 
stocks in this region are assessed in NMFS' U.S. Atlantic SARs (e.g., 
Hayes et al., 2018). All values presented in Table 3 are the most 
recent available at the time of publication and are available in the 
draft 2019 Atlantic SARs, which are available online at: 
www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports.

                                         Table 3--Marine Mammal Species Potentially Present in the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      ESA/MMPA     Stock abundance (CV,
                                                                                      status;        Nmin, most recent                         Annual M/
            Common name                Scientific name             Stock          strategic (Y/N)    abundance survey)          PBR \3\          SI \4\
                                                                                        \1\                 \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
                                                                   Family Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin................  Tursiops truncatus     Northern Migratory     -/D; Y           6,639 (0.41, 4,759,   48..................   6.1-13.2
                                     truncatus.             Coastal.                                2016).
                                                           Southern Migratory     -/D; Y           3,751 (0.06, 2,353,   23..................     0-14.3
                                                            Coastal.                                2016).
                                                           Northern North         -/-; Y           823 (0.06, 782,       7.8.................   0.8-18.2
                                                            Carolina Estuarine.                     2013).
                                                           Southern North         -/-; Y           Unknown.............  Unknown.............    0.4-0.6
                                                            Carolina Estuarine.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR (see
  footnote 3) or which is determined to be declining and likely to be listed under the ESA within the foreseeable future.
\2\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. The most recent abundance survey that is reflected in the abundance
  estimate is presented; there may be more recent surveys that have not yet been incorporated into the estimate.

[[Page 14891]]

 
\3\ Potential biological removal, defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a
  marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population size (OSP).
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a range.

    Bottlenose dolphins range widely in temperate and tropical waters 
and are found from deep, offshore to coastal areas, including bays, 
estuaries and river mouths. In the western North Atlantic, there are 
two morphologically and genetically distinct bottlenose dolphin 
morphotypes described as the coastal and offshore forms (Duffield et 
al., 1983; Hersh and Duffield, 1990; Mead and Potter, 1995; Curry and 
Smith, 1997; Rosel et al., 2009). These forms are genetically distinct 
based upon both mitochondrial and nuclear markers (Hoelzel et al., 
1998; Rosel et al., 2009). The offshore morphotype does not occur in 
waters of Pamlico Sound and is not discussed here. The coastal 
morphotype is continuously distributed in nearshore coastal and 
estuarine waters along the U.S. Atlantic coast south of Long Island, 
New York, around the Florida peninsula and into the Gulf of Mexico. 
Primary habitat for coastal dolphins generally includes waters less 
than 20 m deep (e.g., Garrison et al., 2003).
    Initially, a single stock of coastal bottlenose dolphins was 
thought to migrate seasonally between New Jersey (summer months) and 
central Florida based on seasonal patterns in strandings during a large 
scale mortality event occurring during 1987-1988 (Scott et al., 1988). 
However, re-analysis of stranding data and extensive analysis of 
genetic, photo-identification, and satellite telemetry data demonstrate 
a complex mosaic of coastal bottlenose dolphin stocks (Zolman, 2002; 
McLellan et al., 2002; Rosel et al., 2009; Hayes et al., 2018). 
Integrated analysis of these multiple lines of evidence suggests that 
there are five coastal stocks of bottlenose dolphins, including the 
migratory stocks that may be present in the action area.
    The coastal morphotype inhabits inshore estuarine waters in 
addition to coastal nearshore and continental shelf waters, with 
multiple lines of evidence supporting demographic separation between 
bottlenose dolphins residing within different estuaries along the 
Atlantic coast (Wells et al., 1987; Scott et al., 1990; Wells et al., 
1996; Zolman, 2002; Speakman et al., 2006; Stolen et al., 2007; Balmer 
et al., 2008; Mazzoil et al., 2008). In some cases, studies have 
identified communities of resident dolphins that are seen within 
relatively restricted home ranges year-round, as well as year-round 
resident dolphins repeatedly observed across multiple years (Zolman, 
2002; Speakman et al., 2006; Stolen et al., 2007; Mazzoil et al., 
2008). A few published studies demonstrate that these resident animals 
are genetically distinct from animals in nearby coastal waters and/or 
from animals residing in nearby estuarine areas (Caldwell, 2001; Rosel 
et al., 2009; Litz et al., 2012). However, the degree of spatial 
overlap between estuarine and coastal populations remains unclear, and 
the degree of movement of resident estuarine animals into coastal 
waters on seasonal or shorter time scales is poorly understood (Hayes 
et al., 2018). Bottlenose dolphins inhabiting primarily estuarine 
habitats are considered distinct stocks from those inhabiting coastal 
habitats.
    The spatial extent of the coastal stocks, their potential seasonal 
movements, and their relationships with estuarine stocks are poorly 
understood (Hayes et al., 2018). The coastal stocks include migratory 
stocks that move south seasonally from mid-Atlantic coastal waters. The 
northern migratory stock is best defined by its distribution during 
warm water months (best described by July and August) when it overlaps 
with the fewest stocks (Hayes et al., 2018). During warm water months, 
this stock occupies coastal waters from the shoreline to approximately 
the 20-m isobath between Assateague, Virginia, and Long Island, New 
York (Garrison et al., 2017b). The stock migrates in late summer and 
fall and, during cold water months (best described by January and 
February), occupies coastal waters from approximately Cape Lookout, 
North Carolina, to the North Carolina/Virginia border (Garrison et al., 
2017b).
    The spatial distribution and migratory movements of the southern 
migratory stock are poorly understood and have been defined based on 
movement data from telemetry and photo-ID studies, and stable isotope 
studies. The stock is best delimited in warm water months, when it 
overlaps least with other stocks, as bottlenose dolphins that occupy 
coastal waters from Cape Lookout to Assateague, Virginia. Telemetry 
data provide evidence for a stock of dolphins migrating seasonally 
along the coast between North Carolina and northern Florida (Garrison 
et al., 2017b), and suggest that during October-December the stock 
occupies waters of southern North Carolina (south of Cape Lookout). 
During January-March, the stock appears to move as far south as 
northern Florida and, during April-June, the stock moves back north to 
North Carolina to Cape Hatteras. During the warm water months of July-
August, the stock is presumed to occupy coastal waters north of Cape 
Lookout, North Carolina, to Assateague, Virginia.
    The northern North Carolina estuarine system (NNCES) stock is best 
defined as animals that occupy primarily waters of the Pamlico Sound 
estuarine system (which also includes Core, Roanoke, and Albemarle 
sounds, and the Neuse River) during warm water months (July-August). 
Members of this stock also use coastal waters (<=1 km from shore) of 
North Carolina from Beaufort north to Virginia Beach, Virginia 
(Garrison et al. 2017a). Many of these animals move out of the 
estuaries during colder water months and occupy coastal waters (<=3 km 
from shore) between the New River and Oregon Inlet, North Carolina 
(Garrison et al. 2017a). However, others continue to be present in the 
Pamlico Sound estuarine system during cold water months (Goodman Hall 
et al. 2013). The timing of the seasonal movements into and out of 
Pamlico Sound and north along the coast likely occurs with some inter-
annual variability related to seasonal changes in water temperatures 
and/or prey availability.
    The southern North Carolina estuarine system (SNCES) stock is best 
defined as animals occupying estuarine and nearshore coastal waters 
(<=3 km from shore) between the Little River Inlet estuary (33.9[deg] 
N), inclusive of the estuary (near the North Carolina/South Carolina 
border), and the New River (34.5[deg] N) during cold water months (best 
defined as January and February). Members of this stock do not 
undertake large-scale migratory movements. Instead, they expand their 
range only slightly northward during warmer months into estuarine 
waters and nearshore waters (<=3 km from shore) of southern North 
Carolina as far as central Core Sound and southern Pamlico Sound 
(Garrison et al. 2017b). SNCES stock animals have not been observed to 
move north of Cape Lookout in coastal waters nor into the main portion 
of Pamlico Sound during warm water months (Garrison et al. 2017b).
    The four potentially affected stocks likely exhibit seasonal 
spatial overlap to varying degrees. The northern and southern migratory 
stocks may overlap in coastal waters of northern North Carolina and 
Virginia during spring and

[[Page 14892]]

fall migratory periods, but the degree of overlap is unknown and it may 
vary depending on annual water temperature (Garrison et al. 2016). When 
the northern migratory stock has migrated in cold water months to 
coastal waters from just north of Cape Hatteras, North Carolina, to 
just south of Cape Lookout, North Carolina, it overlaps spatially with 
the NNCES stock (Garrison et al. 2017b). Depending on the timing of the 
northward migration in the spring, it may overlap with the NNCES stock 
in coastal waters (<1 km from shore) as far north as Virginia Beach, 
Virginia, and the mouth of the Chesapeake Bay. The northern migratory 
stock may also overlap with the SNCES stock (Garrison et al. 2017b) in 
nearshore coastal waters south of Cape Hatteras in winter, although the 
degree of overlap with is not well defined. The southern migratory 
stock may overlap with the SNCES stock in coastal waters <=3 km from 
shore during October-December (Garrison et al. 2017b). During April-
June, the southern migratory stock overlaps in coastal waters with both 
the SNCES and NNCES stocks and, during July-August, likely overlaps in 
coastal waters with the NNCES stock. During warm water months (best 
defined as July and August), the NNCES and SNCES stocks overlap in 
estuarine waters near Beaufort, North Carolina, and in southern Pamlico 
Sound (Garrison et al. 2017b). However, SNCES stock animals were not 
observed to move north of Cape Lookout in coastal waters nor into the 
main portion of Pamlico Sound during warm water months (Garrison et al. 
2017b) thereby limiting the amount of overlap between the two stocks. 
Overall, most overlap between the coastal migratory stocks and the 
estuarine stocks is likely to occur within nearshore coastal waters 
outside of Pamlico Sound. Based on the information related to seasonal 
distribution discussed above, we assume that animals from the various 
stocks could occur in the vicinity of the training areas as follows: 
Northern migratory dolphins from August-June, southern migratory 
dolphins from April-December, NNCES stock animals year-round, and SNCES 
stock animals from June-October.
    The current population size of the SNCES stock is considered 
unknown due to the age of existing survey data. An initial abundance 
estimate for common bottlenose dolphins occurring within the boundaries 
of the SNCES stock was based on a photo-ID mark-recapture survey of 
North Carolina waters inshore of the barrier islands, conducted during 
July 2000 (Read et al., 2003). This study estimated the number of 
animals in the inshore waters of North Carolina occupied by the SNCES 
stock at 141 (CV=0.15, 95 percent CI: 112-200), but the estimate did 
not account for the portion of the stock that may have occurred in 
coastal waters. Summer aerial survey data from 2002 (Garrison et al., 
2016) were therefore used to account for the portion of the stock in 
coastal waters. The abundance estimate for a 3-km strip from Cape 
Lookout to the North Carolina-South Carolina border was 2,454 
(CV=0.53), yielding a total of 2,595 (CV=0.50). This estimate is likely 
positively biased as some animals in coastal waters may have belonged 
to a coastal stock.
    A photo-ID mark-recapture study was conducted by Urian et al. 
(2013) in July 2006 using similar methods to those in Read et al. 
(2003) and included estuarine waters of North Carolina from, and 
including, the Little River Inlet estuary (near the North Carolina/
South Carolina border) to, and including, Pamlico Sound. The 2006 
survey also included coastal waters up to Cape Hatteras extending up to 
1 km from shore. In order to estimate abundance for the SNCES stock 
alone, only sightings south of 34[deg]46' N in central Core Sound were 
used. The resulting abundance estimate included a correction for the 
proportion of dolphins with non-distinct fins in the population. The 
abundance estimate for the SNCES stock based upon photo-ID mark-
recapture surveys in 2006 was 188 animals (CV=0.19, 95 percent CI: 118-
257; Urian et al. 2013). This estimate is probably negatively biased as 
the survey covered waters only to 1 km from shore and did not include 
habitat in southern Pamlico Sound.
Bottlenose Dolphin Occurrence within Pamlico Sound
    In Pamlico Sound, bottlenose dolphins concentrate in shallow water 
habitats along shorelines, and few, if any, individuals are present in 
the central portions of the sound (Gannon, 2003; Read et al., 2003a, 
2003b). The dolphins utilize shallow habitats, such as tributary creeks 
and the edges of the Neuse River, where the bottom depth is less than 
3.5 m (11.5 ft) (Gannon, 2003). Fine-scale distribution of dolphins 
seems to relate to the presence of topography or vertical structure, 
such as the steeply-sloping bottom near the shore and oyster reefs. 
Bottlenose dolphins may use these features to facilitate prey capture 
(Gannon, 2003).
    In 2000, Duke University Marine Lab (Duke) conducted a boat-based 
mark-recapture survey throughout the estuaries, bays and sounds of 
North Carolina (discussed above in context of the SNCES stock 
population abundance; Read et al., 2003). The 2000 boat-based survey 
produced an estimate of 919 dolphins for the northern inshore waters 
divided by an estimated 5,015 km\2\ (1,936 mi\2\) survey area (equating 
to a density estimate of 0.183 dolphins per km\2\). In a follow-on 
aerial study (July, 2002 to June, 2003) specifically in and around BT-9 
and BT-11, Duke reported one sighting in the restricted area 
surrounding BT-9, two sightings in proximity to BT-11, and seven 
sightings in waters adjacent to the bombing targets (Maher, 2003). In 
total, the study observed 276 bottlenose dolphins ranging in group size 
from 2 to 70 animals.
    Aerial surveys were flown in Pamlico and Core sounds from July 2004 
to April 2006 (Goodman et al. 2007). These surveys yielded density 
estimates for bottlenose dolphins in the western portion of Pamlico 
Sound (including the MCAS Cherry Point Range Complex) ranging from 
0.0272/km\2\ in winter to 0.2158/km\2\ in autumn. Correction factors 
were incorporated for both animals residing at the surface but not 
sighted during the aerial survey and animals below the surface that 
were not sighted.
    Results of a passive acoustic monitoring effort conducted from 
2006-2007 by Duke University researchers detected that dolphin 
vocalizations in the BT-11 vicinity were higher in August and September 
than vocalization detection at BT-9 (Read et al., 2007). Additionally, 
detected vocalizations of dolphins were more frequent at night for the 
BT-9 area and during early morning hours at BT-11 (Read et al., 2007).
    Biologically Important Areas--LaBrecque et al. (2015) recognize 
multiple biologically important areas (BIA) for small and resident 
populations of bottlenose dolphins in the mid- and south Atlantic. 
Small and resident population BIAs are areas and times within which 
small and resident populations occupy a limited geographic extent, and 
are therefore necessarily important areas for those populations. Here, 
these include areas defined for the SNCES and NNCES populations and 
correspond with the stock boundaries described above.
    Unusual Mortality Events (UME)--A UME is defined under the MMPA as 
``a stranding that is unexpected; involves a significant die-off of any 
marine mammal population; and demands immediate response.'' Beginning 
in July 2013, elevated strandings of bottlenose dolphins were observed 
along the Atlantic coast from New York to Florida. The investigation 
was closed in

[[Page 14893]]

2015, with the UME ultimately being attributed to cetacean 
morbillivirus (though additional contributory factors are under 
investigation; www.fisheries.noaa.gov/national/marine-life-distress/2013-2015-bottlenose-dolphin-unusual-mortality-event-mid-atlantic; 
accessed February 24, 2020). Dolphin strandings during 2013-15 were 
greater than six times higher than the annual average from 2007-12, 
with the most strandings reported from Virginia, North Carolina, and 
Florida. A total of approximately 1,650 bottlenose dolphins stranded 
from June 2013 to March 2015. Only one offshore ecotype dolphin has 
been identified, meaning that over 99 percent of affected dolphins were 
of the coastal ecotype. Research, to include analyses of stranding 
samples and post-UME monitoring and modeling of surviving populations, 
will continue in order to better understand the impacts of the UME on 
the affected stocks. Notably, an earlier major UME in 1987-88 was also 
caused by morbillivirus, and led to the current designation of all 
coastal stocks of Atlantic bottlenose dolphin as depleted under the 
MMPA. Over 740 stranded dolphins were recovered during that event.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans).
    Subsequently, NMFS (2018) described generalized hearing ranges for 
these marine mammal hearing groups. Generalized hearing ranges were 
chosen based on the approximately 65 decibel (dB) threshold from the 
normalized composite audiograms, with the exception for lower limits 
for low-frequency cetaceans where the lower bound was deemed to be 
biologically implausible and the lower bound from Southall et al. 
(2007) retained. Marine mammal hearing groups and their associated 
hearing ranges are provided in Table 4.

                  Table 4--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
               Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen         7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,      150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true          275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus cruciger &
 L. australis).
Phocid pinnipeds (PW) (underwater) (true     50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea     60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Bottlenose dolphins are categorized as mid-frequency cetaceans.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    Sections 6, 7, and 9 of the USMC's application includes a summary 
of the ways that components of the specified activity may impact marine 
mammals and their habitat, including specific discussion of potential 
effects to marine mammals from noise and other stressors produced 
through the use of munitions in training exercises, and a summary of 
the results of monitoring during previous years' training exercises. We 
have reviewed the USMC's discussion of potential effects for accuracy 
and completeness in its application and refer to that information 
rather than repeating it here. Here, we provide a brief technical 
background on sound, on the characteristics of certain sound types, and 
on metrics used in this proposal, as well as a brief overview of the 
potential effects to marine mammals associated with use of explosive 
munitions and the associated criteria for evaluation of these potential 
effects.
    Alternatively, NMFS has included a lengthy discussion of the 
potential effects of similar activities on marine mammals, including 
specifically from training exercises using munitions, in other Federal 
Register notices, including prior notices for the same specified 
activity. For full detail, we refer the reader to these notices. For 
previous discussion provided in context of the same specified activity, 
please see 79 FR 41374 (July 15, 2014). This previous discussion of 
potential effects remains relevant. For more recent discussion of 
similar effects incorporating the most current literature, please see, 
e.g., 85 FR 5782 (January 31, 2020); 83 FR 29872 (June 26, 2018); 82 FR 
61372 (December 27, 2017), or view documents available online at 
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
    The planned training exercises have the potential to cause take of 
marine mammals by exposing them to impulsive noise and pressure waves 
generated by live ordnance detonation at or near the surface of the 
water. Exposure to energy or pressure resulting from these detonations 
could result in non-lethal injury (Level A harassment) or disturbance 
(Level B harassment). Under the previous incidental take authorization 
issued to USMC, serious injury and/or mortality was authorized as a 
precaution. However, no such incidents have ever been recorded in 
association with USMC training activities and none are expected. As 
such, they are not proposed for authorization herein. In addition, NMFS 
also considered the potential for harassment from vessel and aircraft 
operations. The potential effects of impulsive sound sources 
(underwater detonations) from the proposed training

[[Page 14894]]

activities may include one or more of the following: tolerance, 
masking, disturbance, hearing threshold shift, and stress responses.
    The Estimated Take section later in this document includes a 
quantitative analysis of the number of individuals that are expected to 
be taken by the specified activity. The Negligible Impact Analysis and 
Determination section includes an analysis of how these activities will 
impact marine mammals and considers the content of this section, the 
Estimated Take section, and the Proposed Mitigation section, to draw 
conclusions regarding the likely impacts of these activities on the 
reproductive success or survivorship of individuals and from that on 
the affected marine mammal populations.

Description of Sound Sources

    This section contains a brief technical background on sound, on the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document. For general 
information on sound and its interaction with the marine environment, 
please see, e.g., Au and Hastings (2008); Richardson et al. (1995); 
Urick (1983).
    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in hertz or cycles per second. Wavelength is the distance 
between two peaks or corresponding points of a sound wave (length of 
one cycle). Higher frequency sounds have shorter wavelengths than lower 
frequency sounds, and typically attenuate (decrease) more rapidly, 
except in certain cases in shallower water. Amplitude is the height of 
the sound pressure wave or the ``loudness'' of a sound and is typically 
described using the relative unit of the decibel (dB). A sound pressure 
level (SPL) in dB is described as the ratio between a measured pressure 
and a reference pressure (for underwater sound, this is 1 microPascal 
([mu]Pa)), and is a logarithmic unit that accounts for large variations 
in amplitude. Therefore, a relatively small change in dB corresponds to 
large changes in sound pressure. The source level (SL) represents the 
SPL referenced at a distance of 1 m from the source (referenced to 1 
[mu]Pa), while the received level is the SPL at the listener's position 
(referenced to 1 [mu]Pa).
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Root mean square is calculated by squaring 
all of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick, 1983). Root mean square accounts for 
both positive and negative values; squaring the pressures makes all 
values positive so that they may be accounted for in the summation of 
pressure levels (Hastings and Popper, 2005). This measurement is often 
used in the context of discussing behavioral effects, in part because 
behavioral effects, which often result from auditory cues, may be 
better expressed through averaged units than by peak pressures.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy in a stated frequency band over a stated 
time interval or event and considers both intensity and duration of 
exposure. The per-pulse SEL is calculated over the time window 
containing the entire pulse (i.e., 100 percent of the acoustic energy). 
SEL is a cumulative metric; it can be accumulated over a single pulse, 
or calculated over periods containing multiple pulses. Cumulative SEL 
represents the total energy accumulated by a receiver over a defined 
time window or during an event. Peak sound pressure (also referred to 
as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous 
sound pressure measurable in the water at a specified distance from the 
source and is represented in the same units as the rms sound pressure.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in a 
manner similar to ripples on the surface of a pond and may be either 
directed in a beam or beams or may radiate in all directions 
(omnidirectional sources), as is the case for sound produced by the 
pile driving activity considered here. The compressions and 
decompressions associated with sound waves are detected as changes in 
pressure by aquatic life and man-made sound receptors such as 
hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound, which is 
defined as environmental background sound levels lacking a single 
source or point (Richardson et al., 1995). The sound level of a region 
is defined by the total acoustical energy being generated by known and 
unknown sources. These sources may include physical (e.g., wind and 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
(e.g., vessels, dredging, construction) sound. A number of sources 
contribute to ambient sound, including wind and waves, which are a main 
source of naturally occurring ambient sound for frequencies between 200 
Hz and 50 kHz (Mitson, 1995). In general, ambient sound levels tend to 
increase with increasing wind speed and wave height. Precipitation can 
become an important component of total sound at frequencies above 500 
Hz, and possibly down to 100 Hz during quiet times. Marine mammals can 
contribute significantly to ambient sound levels, as can some fish and 
snapping shrimp. The frequency band for biological contributions is 
from approximately 12 Hz to over 100 kHz. Sources of ambient sound 
related to human activity include transportation (surface vessels), 
dredging and construction, oil and gas drilling and production, 
geophysical surveys, sonar, and explosions. Vessel noise typically 
dominates the total ambient sound for frequencies between 20 and 300 
Hz. In general, the frequencies of anthropogenic sounds are below 1 kHz 
and, if higher frequency sound levels are created, they attenuate 
rapidly.
    The sum of the various natural and anthropogenic sound sources that 
comprise ambient sound at any given location and time depends not only 
on the source levels (as determined by current weather conditions and 
levels of biological and human activity) but also on the ability of 
sound to propagate through the environment. In turn, sound propagation 
is dependent on the spatially and temporally varying properties of the 
water column and sea floor, and is frequency-dependent. As a result of 
the dependence on a large number of varying factors, ambient sound 
levels can be expected to vary widely over both coarse and fine spatial 
and temporal scales. Sound levels at a given frequency and location can 
vary by 10-20 decibels (dB) from day to day (Richardson et al., 1995). 
The result is that, depending on the source type and its intensity, 
sound from the specified activity may be a negligible addition to the 
local environment or could form a distinctive signal that may affect 
marine mammals. Details of source types are described in the following 
text.
    Sounds are often considered to fall into one of two general types: 
Pulsed and non-pulsed (defined in the following). The distinction 
between these two sound types is important because they have differing 
potential to

[[Page 14895]]

cause physical effects, particularly with regard to hearing (e.g., 
Ward, 1997 in Southall et al., 2007). Please see Southall et al. (2007) 
for an in-depth discussion of these concepts. The distinction between 
these two sound types is not always obvious, as certain signals share 
properties of both pulsed and non-pulsed sounds. A signal near a source 
could be categorized as a pulse, but due to propagation effects as it 
moves farther from the source, the signal duration becomes longer 
(e.g., Greene and Richardson, 1988).
    Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic 
booms, impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur 
either as isolated events or repeated in some succession. Pulsed sounds 
are all characterized by a relatively rapid rise from ambient pressure 
to a maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or intermittent (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems. The 
duration of such sounds, as received at a distance, can be greatly 
extended in a highly reverberant environment.

Mortality

    Mortality risk assessment may be considered in terms of direct 
injury, which includes primary blast injury and barotrauma. The 
potential for direct injury of marine mammals has been inferred from 
terrestrial mammal experiments and from post-mortem examination of 
marine mammals believed to have been exposed to underwater explosions 
(Finneran and Jenkins, 2012; Ketten et al., 1993; Richmond et al., 
1973). Actual effects on marine mammals may differ from terrestrial 
animals due to anatomical and physiological differences, such as a 
reinforced trachea and flexible thoracic cavity, which may decrease the 
risk of injury (Ridgway and Dailey, 1972).
    Primary blast injuries result from the initial compression of a 
body exposed to a blast wave, and are usually limited to gas-containing 
structures (e.g., lung and gut) and the auditory system (U.S. 
Department of the Navy, 2001b). Barotrauma refers to injuries caused 
when large pressure changes occur across tissue interfaces, normally at 
the boundaries of air-filled tissues such as the lungs. Primary blast 
injury to the respiratory system may be fatal depending upon the 
severity of the trauma. Rupture of the lung may introduce air into the 
vascular system, producing air emboli that can restrict oxygen delivery 
to the brain or heart.
    Thresholds for evaluation of potential for mortality are based on 
the level of impact that would cause extensive lung injury to one 
percent of exposed animals (i.e., an impact level from which one 
percent of exposed animals would not recover) (Finneran and Jenkins, 
2012). The threshold represents the expected onset of mortality, where 
99 percent of exposed animals would be expected to survive. Most 
survivors would have moderate blast injuries. The lethal exposure level 
of blast noise, associated with the positive impulse pressure of the 
blast, is expressed as Pa[middot]s and is determined using the Goertner 
(1982) modified positive impulse equation. This equation incorporates 
source/animal depths and the mass of a newborn calf for the affected 
species. The threshold is conservative because animals of greater mass 
can withstand greater pressure waves, and newborn calves typically make 
up a very small percentage of any cetacean group.

Injury (Level A Harassment)

    Potential injuries that may occur to marine mammals include blast 
related injury: Gastrointestinal (GI) tract injury and slight lung 
injury, and irrecoverable auditory damage. These injury categories are 
all types of Level A harassment as defined in the MMPA.
    Slight Lung Injury--This threshold is based on a level of lung 
injury from which all exposed animals are expected to survive (zero 
percent mortality) (Finneran and Jenkins, 2012). Similar to the 
mortality determination, the metric is positive impulse and the 
equation for determination is that of the Goertner injury model (1982), 
corrected for atmospheric and hydrostatic pressures and based on the 
cube root scaling of body mass (Richmond et al., 1973; U.S. Department 
of the Navy, 2001b).
    Gastrointestinal Tract Injuries--GI tract injuries are correlated 
with the peak pressure of an underwater detonation. GI tract injury 
thresholds are based on the results of experiments in which terrestrial 
mammals were exposed to small charges. The peak pressure of the shock 
wave was found to be the causal agent in recoverable contusions 
(bruises) in the GI tract (Richmond et al., 1973, in Finneran and 
Jenkins, 2012).
    Auditory Damage--Auditory injury, or permanent threshold shift 
(PTS), is not fully recoverable and therefore results in a permanent 
decrease in hearing sensitivity. As there have been no studies to 
determine the onset of PTS in marine mammals, this threshold is 
estimated from available information associated with temporary 
threshold shift (TTS), i.e., recoverable auditory damage.

Non-Injurious Impacts (Level B Harassment)

    Two categories of Level B harassment are currently recognized: TTS 
and behavioral impacts. Although TTS is a physiological impact, it is 
not considered injury because auditory structures are temporarily 
fatigued instead of being permanently damaged.

Behavioral Impacts

    Behavioral impacts refer to disturbances that may occur at sound 
levels below those considered to cause TTS in marine mammals, 
particularly in cases of multiple detonations. During an activity with 
a series of explosions (not concurrent multiple explosions shown in a 
burst), an animal is expected to exhibit a startle reaction to the 
first detonation followed by a behavioral response after multiple 
detonations. At close ranges and high sound levels, avoidance of the 
area around the explosions is the assumed behavioral response in most 
cases. Other behavioral impacts may include decreased ability to feed, 
communicate, migrate, or reproduce, among others.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform NMFS' 
negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. For this military readiness activity, the MMPA defines 
harassment as (i) Any act that injures or has the significant potential 
to injure a marine mammal or marine mammal stock in the wild (Level A 
harassment); or (ii) Any act that disturbs or is likely to disturb a 
marine mammal or marine mammal stock in the wild by causing disruption 
of natural

[[Page 14896]]

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 would primarily be by Level B harassment, in the 
form of disruption of behavioral patterns and temporary threshold 
shift, for individual marine mammals resulting from exposure to 
acoustic stressors. A small amount of Level A harassment, in the form 
of permanent threshold shift, is anticipated and proposed for 
authorization. No Level A harassment is anticipated to occur in the 
form of gastrointestinal (GI) tract or lung injury. No serious injury 
or mortality is anticipated or proposed to be authorized for this 
activity. Below we describe how the take is estimated.
    Generally speaking, we estimate take from exposure to sound by 
considering: (1) Acoustic thresholds above which NMFS believes the best 
available science indicates marine mammals will be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day; (3) the density or occurrence of marine mammals within these 
ensonified areas; and, (4) and the number of days of activities. For 
this proposed IHA, the U.S. Navy employed a sophisticated model known 
as the Navy Acoustic Effects Model (NAEMO) for assessing the impacts of 
underwater sound. The USMC then incorporated these results into their 
application.

Acoustic Thresholds

    Using the best available science, NMFS applies acoustic thresholds 
that identify the received level of underwater sound above which 
exposed marine mammals would be reasonably expected to be behaviorally 
harassed (equated to Level B harassment) or to incur PTS of some degree 
(equated to Level A harassment). Thresholds have also been developed to 
identify the pressure levels above which animals may incur different 
types of tissue damage from exposure to pressure waves from explosive 
detonation.
    The criteria and thresholds used to estimate potential pressure and 
energy impacts to marine mammals resulting from detonations are as 
presented in the U.S. Navy's Phase III criteria documentation (DoN, 
2017). These criteria represent the best available science. Criteria 
used to analyze impacts to marine mammals include mortality, harassment 
that causes or is likely to cause injury (Level A harassment) and 
harassment that disrupts or is likely to disrupt natural behavior 
patterns (Level B harassment).
    Harassment (Auditory and Behavioral)--In order to evaluate the 
potential for harassment resulting from auditory damage, NMFS's 
``Technical Guidance for Assessing the Effects of Anthropogenic Sound 
on Marine Mammal Hearing'' (NMFS, 2018) identifies dual criteria to 
assess the potential for permanent (Level A harassment) and temporary 
(Level B harassment) threshold shift to occur for different marine 
mammal groups (based on hearing sensitivity) as a result of exposure to 
noise. The technical guidance identifies the received levels, or 
thresholds, above which individual marine mammals are predicted to 
experience changes in their hearing sensitivity for all underwater 
anthropogenic sound sources, and reflects the best available science on 
the potential for noise to affect auditory sensitivity by:
     Dividing sound sources into two groups (i.e., impulsive 
and non-impulsive) based on their potential to affect hearing 
sensitivity;
     Choosing metrics that best address the impacts of noise on 
hearing sensitivity, i.e., peak sound pressure level (peak SPL) 
(reflects the physical properties of impulsive sound sources to affect 
hearing sensitivity) and cumulative sound exposure level (cSEL) 
(accounts for not only level of exposure but also duration of 
exposure); and
     Dividing marine mammals into hearing groups and developing 
auditory weighting functions based on the science supporting that not 
all marine mammals hear and use sound in the same manner.
    The premise of the dual criteria approach is that, while there is 
no definitive answer to the question of which acoustic metric is most 
appropriate for assessing the potential for injury, both the received 
level and duration of received signals are important to an 
understanding of the potential for auditory injury. Therefore, peak SPL 
is used to define a pressure criterion above which auditory injury is 
predicted to occur, regardless of exposure duration (i.e., any single 
exposure at or above this level is considered to cause auditory 
injury), and cSEL is used to account for the total energy received over 
the duration of sound exposure (i.e., both received level and duration 
of exposure) (South all et al., 2007, 2019; NMFS, 2018). As a general 
principle, whichever criterion is exceeded first (i.e., results in the 
largest insolent) would be used as the effective injury criterion 
(i.e., the more precautionary of the criteria). Note that cSEL acoustic 
threshold levels incorporate marine mammal auditory weighting 
functions, while peak pressure thresholds do not (i.e., flat or un 
weighted). Weighting functions for each hearing group (e.g., low-, mid-
, and high-frequency cetaceans) are described in NMFS (2018).
     NMFS (2018) recommends 24 hours as a maximum accumulation period 
relative to cSEL thresholds. These thresholds were developed by 
compiling and synthesizing the best available science, and are provided 
in Table 5 below. The references, analysis, and methodology used in the 
development of the thresholds are described in NMFS (2018), which is 
available online at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
    In order to evaluate the potential for Level B (behavioral) 
harassment resulting from multiple, successive explosive detonations 
(i.e., detonations happening at the same location within a 24-hour 
period), the threshold is set 5 dB below the SEL-based TTS threshold.
    Non-Auditory Impacts--As described previously, explosive 
detonations have the potential to cause non-serious injury (Level A 
harassment) or mortality/serious injury. These potential effects are 
assumed to occur due to the effects of pressure waves on gas-filled 
structures (i.e., lungs, GI tract). Mortality and slight lung injury 
thresholds are calculated using equations incorporating the assumed 
mass and depth of the mammal:

Mortality threshold (50 percent risk of extensive lung injury) = 
144M1/3(1 + D/10.1)\1/6\ Pas
Injury threshold (50 percent risk of slight lung injury) = 
65.8M1/3(1 + D/10.1)\1/6\ Pas

    Adult and calf mass for bottlenose dolphin are defined based on 
data from ``Criteria and Thresholds for U.S. Navy Acoustic and 
Explosive Impacts to Marine Mammals and Sea Turtles.'' A peak SPL 
threshold determined through experiments on terrestrial mammals is 
assumed to represent the potential for GI tract injury. Relevant 
thresholds for bottlenose dolphins (i.e., mid-frequency cetaceans) are 
provided in Table 5.

[[Page 14897]]



                       Table 5--Explosive Criteria and Thresholds Used for Impact Analyses
----------------------------------------------------------------------------------------------------------------
                      Level A harassment                                       Level B harassment
----------------------------------------------------------------------------------------------------------------
           GI tract injury                     PTS \1\                  TTS \1\                  Behavior
----------------------------------------------------------------------------------------------------------------
243 dB SPL (Pak) \2\.................  185 dB SE L............  170 dB SE L............  165 dB SEL.\3\
                                       230 dB SPL.............  224 dB SPL.............
----------------------------------------------------------------------------------------------------------------
\1\ Dual metric criteria. SEL thresholds are cumulative, referenced to 1 [mu]Pa\2\-s, and weighted according to
  appropriate auditory weighting function. SPL thresholds are peak pressure referenced to 1 [mu]Pa and un
  weighted within generalized hearing range.
\2\ Threshold for 50 percent risk of GI tract injury, used in modeling to assess potential for injuries due to
  underwater explosions. Threshold for 1 percent risk of GI tract injury (237 dB SPL Pak) is used in modeling
  range to effect.
\3\ Applicable to events with multiple explosive detonations within any given 24-hr period. For single
  explosions at received sound levels below hearing loss thresholds, the most likely behavioral response is a
  brief alerting or orienting response. Since no further sounds follow the initial brief impulses, significant
  behavioral reactions would not be expected to occur.

Marine Mammal Occurrence

    Please see Description of Marine Mammals in the Area of Specified 
Activities for details regarding past marine mammal survey effort 
conducted in the Alnico Sound region. A density of 0.183 dolphins per 
square kilometer was used year-round (Read et al., 2003). The USMC and 
NMFS believe that this value, which is consistent with the information 
used to support prior USMC requests for authorization, is most 
appropriate. Although the aerial survey study (Goodman et al., 2007) 
provides seasonal density values, and reports a higher density value 
for some seasons, the USMC believes the Read et al. (2003) survey data 
to represent the better density estimate.
    In order to apportion any predicted exposures to the potentially 
affected stocks, USMC calculated monthly stock-specific proportions of 
each stock expected to be present in the vicinity of the training 
exercises, based on relative stock-specific abundance and available 
information about stock movements and seasonal occurrence in the area. 
Please see Table 3-2 in the USMC application.

Exposure Modeling

    NAEMO is the standard model used by the Navy to estimate the 
potential acoustic effects of proposed Navy training and testing 
activities on marine mammals and was employed by the Navy in this case 
to evaluate the potential effects of the proposed USMC training 
activities. NAEMO is comprised of multiple modules that, in a stepwise 
process (1) define the activity, including sound source 
characteristics, location, and duration; (2) incorporate site-specific 
oceanographic and environmental data required for a scenario 
simulation; (3) generate acoustic propagation data; (4) distribute 
marine species within the modeling environment; (5) execute the 
simulation and record the sound received by each virtual marine mammal 
in the area for every time step that sound is emitted; incorporating 
the scenario definition, sound propagation data, and marine species 
distribution data, ultimately providing raw data output for each 
simulation; (6) provide the computation of estimated effects that 
exceed defined threshold criteria; and (7) generate a report of 
simulation results over multiple scenario runs.
    In summary, source characteristics are integrated with 
environmental data (bathymetry, sound speed, bottom characterization, 
and wind speed) to calculate the three-dimensional sound field for each 
source. Marine species density information is then processed to develop 
a series of distribution files for each species present in the study 
area. Each distribution file varies the abundance and placement of the 
animals based on uncertainty defined in the density and published group 
size. The scenario details, three-dimensional sound field data, and 
marine species distributions are then combined in NAEMO to build 
virtual three-dimensional representations of each event and 
environment. This information is then processed by NAEMO to determine 
the number of marine species exposed in each scenario.
    The NAEMO simulation process is run multiple times for each season 
to provide an average of potential effects on marine species. Each 
iteration reads in the species dive data and introduces variations to 
the marine species distributions in addition to the initial position 
and direction of each platform and ordnance within the designated area. 
Effects criteria and thresholds are then applied to quantify the 
predicted number of marine mammal effects. Results from each iteration 
are averaged to provide the number of marine species effects for a 
given period. A complete description of the NAEMO model and modeling 
approach used for this analysis can be found in the Navy's Phase III 
Quantitative Analysis Technical Report (Blackstock et al., 2017).
    As noted previously, all ordnance expenditure at BT-11 is inert 
and, therefore, only ordnance use at BT-9 is considered in the effects 
analysis described here. The following types of ordnance were modeled: 
Bomb (GBU, BDU, MK), 2.75-in Rocket HE, 5-in Rocket HE, G911 Grenades, 
30 mm HE, and 40 mm HE. Note that live bombs are not planned for use. 
Therefore, we do not provide information related to the modeling. All 
explosives are modeled as detonating at a 0.1-meter depth. Relevant 
parameters are provided in Table 6. For further detail regarding the 
modeling, including details concerning environmental data sources, 
please the USMC application. Table 7 shows the quantitative exposure 
modeling results.

                                         Table 6--Source Characteristics
----------------------------------------------------------------------------------------------------------------
                                                                                  Peak one-third
                                                                   Net explosive   octave (OTO)       Center
                             Source                                weight (lbs)    source level    frequency of
                                                                                       (dB)        peak OTO (Hz)
----------------------------------------------------------------------------------------------------------------
5-in rocket.....................................................              15             229            1008
2.75-in rocket..................................................             4.8             224            1270
Grenade.........................................................             0.5             214            2540
40 mm...........................................................          0.1199             208            4032

[[Page 14898]]

 
30 mm...........................................................          0.1019             207            4032
----------------------------------------------------------------------------------------------------------------


                                                         Table 7--Quantitative Modeling Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Level B harassment                      Level A harassment
                                                         --------------------------------------------------------------------------------
                         Species                                                                             GI tract                        Mortality
                                                            Behavioral          TTS             PTS           injury        Lung injury
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin......................................           72.09           29.99            1.81            0.13            0.01           <0.01
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The exposure modeling results shown in Table 7 support proposed 
bottlenose dolphin take authorization numbers of 102 incidents of Level 
B harassment and 2 incidents of Level A harassment (PTS only). No 
incidents of GI tract injury or lung injury are anticipated.

Proposed Mitigation

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

Mitigation for Marine Mammals and Their Habitat

    NMFS and the USMC have worked to identify potential practicable and 
effective mitigation measures. These measures include the following:
    Visual Monitoring--Range operators conduct or direct visual surveys 
to monitor the target areas for protected species before and after each 
exercise. Range operation and control personnel would monitor the 
target area through two tower-mounted safety and surveillance cameras. 
In addition, when small boats are part of planned exercises and already 
on range, visual checks by boat crew would be performed.
    The remotely operated range cameras are high-resolution cameras 
that allow viewers to see animals at the surface and breaking the 
surface (though not underwater). The camera system has night vision 
(IR) capabilities. Lenses on the camera system have a focal length of 
40 mm to 2200 mm (56x), with view angles of 18 degrees 10' and 13 
degrees 41' respectively. The field of view when zoomed in on the 
Rattan Bay targets will be 23' wide by 17' high, and on the mouth of 
Rattan Bay itself 87' wide by 66' high. Observers using the cameras are 
able to clearly identify ducks floating on waters near the target.
    In the event that a marine mammal is sighted within 914 m (3,000 
ft) of the BT-9 target area, personnel would declare the area as fouled 
and cease training exercises. Personnel would commence operations in 
BT-9 only after the animal has moved 914 m (3,000 ft) away from the 
target area.
    For BT-11, in the event that a marine mammal is sighted anywhere 
within the confines of Rattan Bay, personnel would declare the water-
based targets within Rattan Bay as fouled and cease training exercises. 
Personnel would commence operations in BT-11 only after the animal has 
moved out of Rattan Bay.
    Range Sweeps--MCAS Cherry Point contracts range sweeps with 
commercial support aircraft each weekday morning prior to the 
commencement of the day's range operations. The pilot and aircrew are 
trained in spotting objects in the water. The primary goal of the pre-
exercise sweep is to ensure that the target area is clear of 
unauthorized vessels or persons and protected species. Range sweeps 
would not occur on weekend mornings.
    The sweeps are flown at at 100 to 300 ft (30-90 m) above the water 
surface, at airspeeds between 60 to 100 knots (69 to 115 mph). The crew 
communicates directly with range personnel and can provide immediate 
notification to range operators of a fouled target area due to the 
presence of protected species.
    Aircraft Cold Pass--Standard operating procedures for waterborne 
targets require the pilot to perform a visual check prior to ordnance 
delivery to ensure the target area is clear of unauthorized civilian 
boats and personnel, and protected species. This is referred to as a 
``cold'' or clearing pass. Pilots requesting entry onto the BT-9 and 
BT-11 airspace must perform a low-altitude, cold first pass (a pass

[[Page 14899]]

without any release of ordnance) immediately prior to ordnance delivery 
at the bombing targets both day and night.
    Pilots would conduct the cold pass with the aircraft (helicopter or 
fixed-winged) flying straight and level at altitudes of 61 to 914 m 
(200 to 3,000 ft) over the target area. The viewing angle is 
approximately 15 degrees. A blind spot exists to the immediate rear of 
the aircraft. Based upon prevailing visibility, a pilot can see more 
than one mile forward upon approach. If marine mammals are not present 
in the target area, the Range Controller may grant ordnance delivery as 
conditions warrant.
    Delay of Exercises--The USMC would consider an active range as 
fouled and not available for use if a marine mammal is present within 
914 m (3,000 ft) of the target area at BT-9 or anywhere within Rattan 
Bay (BT-11). Therefore, if USMC personnel observe a marine mammal 
within 914 m (3,000 ft) of the target at BT-9 or anywhere within Rattan 
Bay at BT-11 during the cold pass or from range camera detection, they 
would delay training until the marine mammal moves beyond and on a path 
away from 914 m (3,000 ft) from the BT-9 target or moved out of Rattan 
Bay at BT-11. This mitigation applies to air-to-surface and surface-to-
surface exercises day or night.
    Approximately 15 percent of training activities take place during 
nighttime hours. During these training events, monitoring procedures 
mirror day time operations as range operators first visually search the 
target area with the high-resolution camera. Pilots will then conduct a 
low-altitude first cold pass and utilize night vision capabilities to 
visually check the target area for any surfacing mammals.
    Vessel Operation--All vessels used during training operations would 
abide by NMFS' Southeast Regional Viewing Guidelines designed to 
prevent harassment to marine mammals.
    Stranding Network Coordination--The USMC would coordinate with the 
local NMFS Stranding Coordinator to discuss any unusual marine mammal 
behavior and any stranding, beached live/dead, or floating marine 
mammals that may occur at any time during training activities or within 
24 hours after completion of training.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of such species or stock for subsistence uses.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas).
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
     Mitigation and monitoring effectiveness.
    The USMC proposes to conduct the following monitoring activities:
    Protected Species Observer Training--Operators of small boats, and 
other personnel monitoring for marine mammals from watercraft shall be 
required to take the U.S. Navy's Marine Species Awareness Training. 
Pilots conducting range sweeps shall be instructed on marine mammal 
observation techniques during routine Range Management Department 
briefings. This training would make personnel knowledgeable of marine 
mammals, protected species, and visual cues related to the presence of 
marine mammals and protected species.
    Pre- and Post-Exercise Monitoring--The USMC would conduct pre-
exercise monitoring the morning of an exercise and post-exercise 
monitoring the morning following an exercise, unless an exercise occurs 
on a Friday, in which case the post-exercise sweep would take place the 
following Monday. If the crew sights marine mammals during a range 
sweep, they would collect sighting data and immediately provide the 
information to range personnel who would take appropriate management 
action. Range staff would relay the sighting information to training 
Commanders scheduled on the range after the observation. Range 
personnel would enter the data into the USMC sighting database. 
Sighting data includes the following (collected to the best of the 
observer's ability): (1) Location (either an approximate location or 
latitude and longitude); (2) the platform that sighted the animal; (3) 
date and time; (4) species; (5) number of animals; (6) the animals' 
direction of travel and/or behavior; and (7) weather.
    Long-term Monitoring--MCAS Cherry Point has contracted Duke 
University to develop and test a real-time passive acoustic monitoring 
system that will allow automated detection of bottlenose dolphin 
whistles. The work has been performed in two phases. Phase I was the 
development of an automated signal detector (a software program) to 
recognize the whistles of dolphins at BT-9 and BT-11. Phase II included 
the assembly and deployment of a real-time monitoring unit on one of 
the towers on the BT-9 range. The knowledge base gain from this effort 
helped direct current monitoring initiatives and activities within the 
MCAS Cherry Point Range Complex. The current system layout includes a 
pair of autonomous monitoring units at BT-9 and a single unit in Rattan 
Bay, BT-11. The system is not currently functional due to storm related 
damage and communication link issues. It may be on-line during the 
course of the IHA period. In that case, the Passive Acoustic Monitoring 
system

[[Page 14900]]

will serve as an additional mitigation measure to reduce impacts.
    Reporting--The USMC will submit a report to NMFS no later than 90 
days following expiration of this IHA. This report must summarize the 
type and amount of training exercises conducted, all marine mammal 
observations made during monitoring, and if mitigation measures were 
implemented. The report will also address the effectiveness of the 
monitoring plan in detecting marine mammals.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the training activities 
discover an injured or dead marine mammal, the USMC shall report the 
incident to the Office of Protected Resources (OPR), NMFS and to the 
regional stranding coordinator as soon as feasible. The report must 
include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (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'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. 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's 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, ongoing sources of human-caused mortality, or 
ambient noise levels).
    In order to evaluate the number of takes that might be expected to 
accrue to the different potentially affected stocks, the USMC estimated 
the proportion of dolphins present (based on density information from 
Read et al., 2003) that would belong to each of the potentially 
affected stocks. Please see Table 3-2 of the USMC's application. Based 
on these assumptions, we assume that the total take proposed for 
authorization of 102 incidents of Level B harassment and 2 incidents of 
Level A harassment would proportionally impact the various stocks as 
shown in Table 8.

                                     Table 8--Proportional Effects to Stocks
----------------------------------------------------------------------------------------------------------------
                                                                        Level B harassment            Level A
                              Stock                              --------------------------------   harassment
                                                                    Behavioral          TTS            (PTS)
----------------------------------------------------------------------------------------------------------------
Northern migratory..............................................           38.68           15.19            1.23
Southern migratory..............................................           25.86           10.39            0.45
NNCES...........................................................            6.74            3.70            0.06
SNCES...........................................................            0.82            0.70            0.06
----------------------------------------------------------------------------------------------------------------

    NMFS expects short-term effects such as stress during underwater 
detonations. However, the time scale of individual explosions is very 
limited, and the USMC disperses its training exercises in space and 
time. Consequently, repeated exposure of individual bottlenose dolphins 
to sounds from underwater explosions is not likely and most acoustic 
effects are expected to be short-term and localized. NMFS does not 
expect long-term consequences for populations because the BT-9 and BT-
11 areas continue to support bottlenose dolphins in spite of ongoing 
missions. The best available data do not suggest that there is a 
decline in the Pamlico Sound population due to these exercises.
    The probability that detonation events will overlap in time and 
space with marine mammals is low, particularly given the densities of 
marine mammals in the vicinity of BT-9 and BT-11 and the implementation 
of monitoring and mitigation measures. Moreover, NMFS does not expect 
animals to experience repeat exposures to the same sound source, as 
bottlenose dolphins would likely move away from the source after being 
exposed. In addition, NMFS expects that these isolated exposures, when 
received at distances associated with Level B harassment (behavioral), 
would cause brief startle reactions or short-term behavioral 
modification by the animals. These brief reactions and behavioral 
changes would likely cease when the exposures cease. The Level B 
harassment takes would likely result in dolphins being temporarily 
affected by bombing or gunnery exercises.
    Individual bottlenose dolphins may sustain some level of temporary 
threshold shift (TTS) from underwater detonations. TTS can last from a 
few minutes to days, be of varying degree, and occur across various 
frequency bandwidths. Although the degree of TTS depends on the 
received noise levels and exposure time, studies show that TTS is 
reversible. NMFS expects the animals' sensitivity to recover fully in 
minutes to hours based on the fact that the proposed underwater 
detonations are small in scale and isolated. In summary, we do not 
expect that these levels of received impulse noise from detonations 
would affect annual rates of recruitment or survival. The potential for 
permanent hearing impairment and injury is low due to the incorporation 
of the proposed mitigation measures specified in the proposed 
rulemaking.
    NMFS considers if the specified activities occur during and within 
habitat important to vital life functions to better inform the 
preliminary

[[Page 14901]]

negligible impact determination. Read et al. (2003) concluded that 
dolphins rarely occur in open waters in the middle of North Carolina 
sounds and large estuaries, but instead are concentrated in shallow 
water habitats along shorelines. However, no specific areas have been 
identified as vital reproduction or foraging habitat.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     Impacts will be limited to Level B harassment, primarily 
in the form of behavioral disturbance, and only two incidents of Level 
A harassment in the form of PTS;
     Of the number of total takes proposed to be authorized, 
the expected proportions that may accrue to individual affected stocks 
are low relative to the estimated abundances of the affected stocks;
     There will be no loss or modification of habitat and 
minimal, temporary impacts on prey; and
     Mitigation requirements would minimize impacts.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

    There are no relevant subsistence uses of marine mammals implicated 
by these actions. Therefore, we have 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.

Endangered Species Act (ESA)

    No marine mammal species listed under the ESA are expected to be 
affected by these activities. Therefore, we have determined that 
section 7 consultation under the ESA is not required.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the USMC for conducting training activities in Pamlico 
Sound for a period of one year, provided the previously mentioned 
mitigation, monitoring, and reporting requirements are incorporated. A 
draft of the proposed IHA can be found at www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA. We also request 
comment on the potential renewal of this proposed IHA as described in 
the paragraph below. Please include with your comments any supporting 
data or literature citations to help inform decisions on the request 
for this IHA or a subsequent renewal.
    On a case-by-case basis, NMFS may issue a one-year IHA renewal with 
an additional 15 days for public comments when (1) another year of 
identical or nearly identical activities as described in the 
Description of Proposed Activity section of this notice is planned or 
(2) the activities as described in the Description of Proposed Activity 
section of this notice would not be completed by the time the IHA 
expires and a renewal would allow for completion of the activities 
beyond that described in the Dates and Duration section of this notice, 
provided all of the following conditions are met:
     A request for renewal is received no later than 60 days 
prior to expiration of the current IHA.
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested renewal are identical to the activities analyzed under the 
initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take 
because only a subset of the initially analyzed activities remain to be 
completed under the Renewal); and
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
     Upon review of the request for renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: March 10, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2020-05233 Filed 3-13-20; 8:45 am]
 BILLING CODE 3510-22-P